A creation myth or cosmogonic myth is a type of cosmogony, a symbolicnarrative of how the world began and how people first came to inhabit it. While in popular usage the term myth often refers to false or fanciful stories, members of cultures often ascribe varying degrees of truth to their creation myths. In the society in which it is told, a creation myth is usually regarded as conveying profound truths – metaphorically, symbolically, historically, or literally. They are commonly, although not always, considered cosmogonical myths – that is, they describe the ordering of the cosmos from a state of chaos or amorphousness.
Creation myths often share several features. They often are considered sacred accounts and can be found in nearly all known religious traditions. They are all stories with a plot and characters who are either deities, human-like figures, or animals, who often speak and transform easily. They are often set in a dim and nonspecific past that historian of religion Mircea Eliade termed in illo tempore ('at that time'). Creation myths address questions deeply meaningful to the society that shares them, revealing their central worldview and the framework for the self-identity of the culture and individual in a universal context.
Creation myths develop in oral traditions and therefore typically have multiple versions; found throughout human culture, they are the most common form of myth.
A "symbolic narrative of the beginning of the world as
understood in a particular tradition and community. Creation myths are
of central importance for the valuation of the world, for the
orientation of humans in the universe, and for the basic patterns of
life and culture."
"Creation myths tell us how things began. All cultures have creation
myths; they are our primary myths, the first stage in what might be
called the psychic life of the species. As cultures, we identify
ourselves through the collective dreams we call creation myths, or cosmogonies.
... Creation myths explain in metaphorical terms our sense of who we
are in the context of the world, and in so doing they reveal our real
priorities, as well as our real prejudices. Our images of creation say a
great deal about who we are."
A "philosophical and theological elaboration of the primal myth of
creation within a religious community. The term myth here refers to the
imaginative expression in narrative form of what is experienced or
apprehended as basic reality ... The term creation refers to the
beginning of things, whether by the will and act of a transcendent
being, by emanation from some ultimate source, or in any other way."
Religion professor Mircea Eliade defined the word myth in terms of creation:
Myth narrates a sacred history; it relates an event that took place
in primordial Time, the fabled time of the "beginnings." In other words,
myth tells how, through the deeds of Supernatural Beings, a reality
came into existence, be it the whole of reality, the Cosmos, or only a
fragment of reality – an island, a species of plant, a particular kind
of human behavior, an institution.
Meaning and function
In Daoist creation myth, "The Way gave birth to unity; unity gave birth to duality; duality gave birth to trinity; trinity gave birth to the myriad creatures." (Daodejing, 4th century BCE)
Creation myths have been around since ancient history and have served important societal roles. Over 100 "distinct" ones have been discovered. All creation myths are in one sense etiological because they attempt to explain how the world formed and where humanity came from. Myths attempt to explain the unknown and sometimes teach a lesson.
Ethnologists and anthropologists who study origin myths say that in the modern context theologians try to discern humanity's meaning from revealed truths and scientists investigate cosmology with the tools of empiricism and rationality, but creation myths define human reality in very different terms. In the past, historians of religion and other students of myth thought of such stories as forms of primitive or early-stage science or religion and analyzed them in a literal
or logical sense. Today, however, they are seen as symbolic narratives
which must be understood in terms of their own cultural context. Charles Long, for example, writes: "The beings referred to in the myth – gods,
animals, plants – are forms of power grasped existentially. The myths
should not be understood as attempts to work out a rational explanation
of deity."
While creation myths are not literal explications,
they do serve to define an orientation of humanity in the world in
terms of a birth story. They provide the basis of a worldview that
reaffirms and guides how people relate to the natural world, to any assumed spiritual world, and to each other. A creation myth acts as a cornerstone for distinguishing primary reality from relative reality, the origin and nature of being from non-being. In this sense cosmogonic myths serve as a philosophy of life – but one expressed and conveyed through symbol rather than through systematic reason. And in this sense they go beyond etiological myths
(which explain specific features in religious rites, natural phenomena,
or cultural life). Creation myths also help to orient human beings in
the world, giving them a sense of their place in the world and the
regard that they must have for humans and nature.
Historian David Christian has summarized issues common to multiple creation myths:
How did everything begin? This is
the first question faced by any creation myth and ... answering it
remains tricky. ... Each beginning seems to presuppose an earlier
beginning. ... Instead of meeting a single starting point, we encounter
an infinity of them, each of which poses the same problem. ... There are
no entirely satisfactory solutions to this dilemma. What we have to
find is not a solution but some way of dealing with the mystery .... And
we have to do so using words. The words we reach for, from God to gravity,
are inadequate to the task. So we have to use language poetically or
symbolically; and such language, whether used by a scientist, a poet, or
a shaman, can easily be misunderstood.
Mythologists
have applied various schemes to classify creation myths found
throughout human cultures. Eliade and his colleague Charles Long
developed a classification based on some common motifs that reappear in stories the world over. The classification identifies five basic types:
Creation ex nihilo in which the creation is through the thought, word, dream, or bodily secretions of a divine being.
Earth-diver creation in which a diver, usually a bird or amphibian sent by a creator, plunges to the seabed through a primordial ocean to bring up sand or mud which develops into a terrestrial world.
Emergence myths in which progenitors pass through a series of worlds and metamorphoses until reaching the present world.
Creation by the dismemberment of a primordial being.
Creation by the splitting or ordering of a primordial unity such as the cracking of a cosmic egg or a bringing order from chaos.
Marta Weigle further developed and refined this typology to highlight nine themes, adding elements such as deus faber,
a creation crafted by a deity, creation from the work of two creators
working together or against each other, creation from sacrifice and
creation from division/conjugation, accretion/conjunction, or secretion.
An alternative system based on six recurring narrative themes was designed by Raymond Van Over:
Primeval abyss, an infinite expanse of waters or space
Originator deity which is awakened or an eternal entity within the abyss
The belief that Godcreated the world out of nothing – ex nihilo – is central today to Judaism, Christianity, and Islam, and the medieval Jewish philosopher Maimonides felt it was the only concept that the three religions shared. Nonetheless, the concept is not found anywhere in the Hebrew Bible. The authors of Genesis 1 were concerned not with the origins of matter
(the material which God formed into the habitable cosmos), but with
assigning roles so that the cosmos should function. In the early 2nd century CE, early Christian scholars were beginning to
see a tension between the idea of world-formation and the omnipotence
of God, and by the beginning of the 3rd century creation ex nihilo had become a fundamental tenet of Christian theology.
Ex nihilo creation is found in creation stories from ancient Egypt, the Rig Veda, and many animistic cultures in Africa, Asia, Oceania, and North America. In most of these stories, the world is brought into being by the
speech, dream, breath, or pure thought of a creator but creation ex
nihilo may also take place through a creator's bodily secretions.
The literal translation of the phrase ex nihilo is "from
nothing" but in many creation myths the line is blurred whether the
creative act would be better classified as a creation ex nihilo or creation from chaos. In ex nihilo
creation myths, the potential and the substance of creation springs
from within the creator. Such a creator may or may not be existing in
physical surroundings such as darkness or water, but does not create the
world from them, whereas in creation from chaos the substance used for
creation is pre-existing within the unformed void.
In creation from chaos myths, there is nothing initially but a
formless, shapeless expanse. In these stories the word "chaos" means
"disorder", and this formless expanse, which is also sometimes called a
void or an abyss, contains the material with which the created world
will be made. Chaos may be described as having the consistency of vapor
or water, dimensionless, and sometimes salty or muddy. These myths
associate chaos with evil and oblivion, in contrast to "order" (cosmos)
which is the good. The act of creation is the bringing of order from
disorder, and in many of these cultures it is believed that at some
point the forces preserving order and form will weaken and the world
will once again be engulfed into the abyss. One example is the Genesis creation narrative from the first chapter of the Book of Genesis.
There are two types of world parent myths, both describing a
separation or splitting of a primeval entity, the world parent or
parents. One form describes the primeval state as an eternal union of
two parents, and the creation takes place when the two are pulled apart.
The two parents are commonly identified as Sky (usually male) and Earth
(usually female), who were so tightly bound to each other in the
primeval state that no offspring could emerge. These myths often depict
creation as the result of a sexual union and serve as genealogical
record of the deities born from it.
In the second form of world parent myths, creation itself springs
from dismembered parts of the body of the primeval being. Often, in
these stories, the limbs, hair, blood, bones, or organs of the primeval
being are somehow severed or sacrificed to transform into sky, earth,
animal or plant life, and other worldly features. These myths tend to
emphasize creative forces as animistic in nature rather than sexual, and
depict the sacred as the elemental and integral component of the
natural world. One example of this is the Norse creation myth described in "Völuspá", the first poem in the Poetic Edda, and in Gylfaginning.
Emergence
In emergence myths, humanity emerges from another world into the one
they currently inhabit. The previous world is often considered the womb
of the earth mother,
and the process of emergence is likened to the act of giving birth. The
role of midwife is usually played by a female deity, like the spider
woman of several mythologies of Indigenous peoples in the Americas. Male
characters rarely figure into these stories, and scholars often
consider them in counterpoint to male-oriented creation myths, like
those of the ex nihilo variety.
Emergence myths commonly describe the creation of people and/or supernatural beings as a staged ascent or metamorphosis
from nascent forms through a series of subterranean worlds to arrive at
their current place and form. Often the passage from one world or stage
to the next is impelled by inner forces, a process of germination or
gestation from earlier, embryonic forms. The genre is most commonly found in Native American cultures where the
myths frequently link the final emergence of people from a hole opening
to the underworld to stories about their subsequent migrations and
eventual settlement in their current homelands.
The earth-diver is a common character in various traditional creation
myths. In these stories a supreme being usually sends an animal (most
often a type of bird, but also crustaceans, insects, and fish in some
narratives) into the primal waters to find bits of sand or mud with which to build habitable land. Some scholars interpret these myths psychologically while others interpret them cosmogonically. In both cases emphasis is placed on beginnings emanating from the depths.
American anthropologist Gladys Reichard
located the distribution of the motif across "all parts of North
America", save for "the extreme north, northeast, and southwest". David Adams Leeming pointed to its existence among the populations of the eastern United States. In a 1977 study, anthropologist Victor Barnouw surmised that the earth-diver motif appeared in "hunting-gathering societies", mainly among northerly groups such as the Hare, Dogrib, Kaska, Beaver, Carrier, Chipewyan, Sarsi, Cree, and Montagnais.
Similar tales are also found among the Chukchi and Yukaghir, the Tatars, and many Finno-Ugric traditions, as well as among the Buryat and the Samoyed. In addition, the earth-diver motif also exists in narratives from Eastern Europe, namely Romani, Romanian, Slavic (namely, Bulgarian, Polish, Ukrainian, and Belarusian), and Lithuanian mythological traditions.
The pattern of distribution of these stories suggest they have a common origin in the eastern Asiatic coastal region, spreading as peoples migrated west into Siberia and east to the North American continent. However, there are examples of this mytheme found well outside of this boreal distribution pattern, for example the West African Yoruba creation myth of Ọbatala and Oduduwa.
Native American narrative
Characteristic of many Native American myths, earth-diver creation
stories begin as beings and potential forms linger asleep or suspended
in the primordial realm. The earth-diver is among the first of them to
awaken and lay the necessary groundwork by building suitable lands where
the coming creation will be able to live. In many cases, these stories
will describe a series of failed attempts to make land before the
solution is found.
Among the indigenous peoples of the Americas, the earth-diver cosmogony is attested in Iroquois mythology: a female sky deity falls from the heavens, and certain animals, the beaver, the otter, the duck, and the muskrat dive in the waters to fetch mud to construct an island.
In a similar story from the Seneca,
people lived in a sky realm. One day, the chief's daughter was
afflicted with a mysterious illness, and the only cure recommended for
her (revealed in a dream) was to lie beside a tree and to have it be dug
up. The people do so, but a man complains that the tree was their
livelihood, and kicks the girl through the hole. She ends up falling
from the sky to a world of only water, but is rescued by waterfowl.
A turtle offers to bear her on its shell, but asked where would be a
definitive dwelling place for her. They decide to create land, and the toad
dives into the depths of the primal sea to get pieces of soil. The toad
puts it on the turtle's back, which grows larger with every deposit of
soil.
In another version from the Wyandot, the Wyandot lived in heaven. The daughter of the Big Chief (or Mighty Ruler) was sick, so the medicine man
recommends that they dig up the wild apple tree that stands next to the
Lodge of the Mighty Ruler, because the remedy is to be found on its
roots. However, as the tree has been dug out, the ground begins to sink
away, and the treetops catch and carry down the sick daughter with it.
As the girl falls from the skies, two swans rescue her on their backs.
The birds decide to summon all the Swimmers and the Water Tribes. Many
volunteer to dive into the Great Water to fetch bits of earth from the
bottom of the sea, but only the toad (female, in the story) is the one
successful.
On several different levels, from neurotransmitters through neuron firing rates to overall activity, the brain seems to "ramp up" before movements. This image depicts the readiness potential (RP), a ramping-up activity measured using EEG.
The onset of the RP begins before the onset of a conscious intention or
urge to act. Some have argued that this indicates the brain
unconsciously commits to a decision before consciousness awareness.
Others have argued that this activity is due to random fluctuations in
brain activity, which drive arbitrary, purposeless movements.
The neuroscience of free will, an area within neurophilosophy, is the study of topics related to free will (including volition and the sense of agency), using neuroscience and the analysis of how findings from such studies may impact the free will debate.
As medical and scientific technology has advanced, neuroscientists have become able to study the brains of living humans, allowing them to observe the brain's decision-making processes and revealing insights into human agency, moral responsibility, and consciousness. One of the pioneering studies in this field was conducted by Benjamin Libet and his colleagues in 1983, and has been the foundation of many studies in the years since. Other studies have attempted to predict the actions of participants before they happen, explore how we know we are responsible for voluntary movements as opposed to being moved by an external force, or how the role of consciousness in decision-making may differ depending on the type of decision being made.
Some areas of the human brain implicated in mental disorders that might be related to free will. Area 25 refers to Brodmann's area 25, related to major depression.
Some philosophers, such as Alfred Mele and Daniel Dennett,
have questioned the language used by researchers, suggesting that "free
will" means different things to different people (e.g., some notions of
"free will" posit that free will is compatible with determinism, while others do not). Dennett insisted that many important and common
conceptions of "free will" are compatible with the emerging evidence
from neuroscience.
Overview
...the current work is in broad agreement with a general trend in
neuroscience of volition: although we may experience that our conscious
decisions and thoughts cause our actions, these experiences are in fact
based on readouts of brain activity in a network of brain areas that
control voluntary action... It is clearly wrong to think of [feeling of
willing something] as a prior intention, located at the very earliest
moment of decision in an extended action chain. Rather, W seems to mark
an intention-in-action, quite closely linked to action execution.
Patrick Haggard discussing an in-depth experiment by Itzhak Fried
The neuroscience of free will encompasses two main fields of study: volition and agency.
Volition, as in the study of voluntary actions, is difficult to define. If human actions are considered as lying along a spectrum based on
conscious involvement in initiating the actions, then reflexes would be
on one end, and fully voluntary actions would be on the other. How these actions are initiated and consciousness' role in producing them is a major area of study in volition.
Agency is the capacity of an actor to act in a given environment.
Within the neuroscience of free will, the sense of agency—the
subjective awareness of initiating, executing, and controlling one's
volitional actions—is usually what is studied.
One significant finding of modern studies is that a person's
brain seems to commit to certain decisions before the person becomes
aware of having made them. Researchers have found a delay of about half a
second or more (discussed in sections below). With contemporary brain
scanning technology, scientists in 2008 were able to predict with 60%
accuracy whether 12 subjects would press a button with their left or
right hand up to 10 seconds before the subject became aware of having
made that choice. These and other findings have led some scientists, like Patrick Haggard, to reject some definitions of "free will".
However, it is very unlikely that a single study could disprove
all definitions of free will. Definitions of free will can vary greatly,
and each must be considered separately in light of existing empirical evidence. There have also been a number of problems regarding studies of free will. Particularly in earlier studies, research relied on self-reported
measures of conscious awareness, but introspective estimates of event
timing were found to be biased or inaccurate in some cases. There is no
agreed-upon measure of brain activity corresponding to conscious
generation of intentions, choices, or decisions, making studying
processes related to consciousness difficult. The existing conclusions
drawn from measurements are also debatable, as they don't necessarily
tell, for example, what a sudden dip in the readings represents. Such a
dip might have nothing to do with unconscious decision because many
other mental processes are going on while performing the task. Although early studies mainly used electroencephalography, more recent studies have used fMRI, single-neuron recordings, and other measures. Researcher Itzhak Fried says that available studies do at least suggest
that consciousness comes in a later stage of decision-making than
previously expected – challenging any versions of "free will" where
intention occurs at the beginning of the human decision process.
Free will as illusion
It may be possible that our intuitions about the role of our
conscious "intentions" have led us astray; it may be the case that we
have confused correlation with causation by believing that conscious awareness necessarily causes the body's movement. This possibility is bolstered by findings in neurostimulation, brain damage, but also research into introspection illusions.
Such illusions show that humans do not have full access to various
internal processes. The discovery that humans possess a determined will
would have implications for moral responsibility or lack thereof.
Neuroscientist, philosopher, and author Sam Harris
believes that we are mistaken in believing the intuitive idea that
intention initiates actions. Harris criticizes the idea that free will
is "intuitive": and that careful introspection will cast doubt on free
will. Harris argues: "Thoughts simply arise in the brain. What else
could they do? The truth about us is even stranger than we may suppose:
The illusion of free will is itself an illusion".
In contrast to this claim, neuroscientist Walter Jackson Freeman III,
discusses the impact of unconscious systems and actions to change the
world according to human intention. Freeman writes: "our intentional
actions continually flow into the world, changing the world and the
relations of our bodies to it. This dynamic system is the self in each
of us, it is the agency in charge, not our awareness, which is
constantly trying to keep up with what we do." To Freeman, the power of intention and action can be independent of awareness.
An important distinction to make is the difference between proximal and distal intentions. Proximal intentions are immediate in the sense that they are about acting now.
For instance, a decision to raise a hand now or press a button now, as
in Libet-style experiments. Distal intentions are delayed in the sense
that they are about acting at a later point in time. For instance,
deciding to go to the store later. Research has mostly focused on
proximal intentions; however, it is unclear to what degree findings will
generalize from one sort of intention to the other.
Relevance of scientific research
Some thinkers like neuroscientist and philosopher Adina Roskies
think that these studies can still only show, unsurprisingly, that
physical factors in the brain are involved before decision-making. In
contrast, Haggard believes that "We feel we choose, but we don't". Researcher John-Dylan Haynes adds: "How can I call a will 'mine' if I don't even know when it occurred and what it has decided to do?". Philosophers Walter Glannon and Alfred Mele think that some scientists
are getting the science right, but misrepresenting modern philosophers.
This is mainly because "free will"
can mean many things: it is unclear what someone means when they say
"free will does not exist". Mele and Glannon say that the available
research is more evidence against any dualistic notions of free will – but that is an "easy target for neuroscientists to knock down". Mele says that most discussions of free will are now in materialistic
terms. In these cases, "free will" means something more like "not
coerced" or that "the person could have done otherwise at the last
moment". The existence of these types of free will is debatable. Mele
agrees, however, that science will continue to reveal critical details
about what goes on in the brain during decision-making.
[Some senses of free will] are compatible with what we are learning
from science... If only that was what scientists were telling people.
But scientists, especially in the last few years, have been on a
rampage – writing ill-considered public pronouncements about free will
which... verge on social irresponsibility.
This issue may be controversial for good reason: there is evidence to suggest that people normally associate a belief in free will with their ability to affect their lives. Philosopher Daniel Dennett, author of Elbow Room and a supporter of deterministic free will,
believes that scientists risk making a serious mistake. He says that
there are types of free will that are incompatible with modern science,
but those kinds of free will are not worth wanting. Other types of "free
will" are pivotal to people's sense of responsibility and purpose (see
also: "believing in free will"), and many of these types are actually compatible with modern science.
The other studies described below have only just begun to shed
light on the role that consciousness plays in actions, and it is too
early to draw very strong conclusions about certain kinds of "free
will". It is worth noting that such experiments so far have dealt only with
free-will decisions made in short time frames (seconds) and may not have
direct bearing on free-will decisions made ("thoughtfully") by the
subject over the course of many seconds, minutes, hours or longer.
Scientists have also only so far studied extremely simple behaviors
(e.g., moving a finger). Adina Roskies points out five areas of neuroscientific research:
Action initiation
Intention
Decision
Inhibition and control
The phenomenology of agency.
For each of these areas Roskies concludes that the science may be
developing our understanding of volition or "will", but it yet offers
nothing for developing the "free" part of the "free will" discussion.
There is also the question of the influence of such interpretations in people's behavior. In 2008, psychologists Kathleen Vohs and Jonathan Schooler
published a study on how people behave when they are prompted to think
that determinism is true. They asked their subjects to read one of two
passages: one suggesting that behavior boils down to environmental or
genetic factors not under personal control; the other neutral about what
influences behavior. The participants then did a few math problems on a
computer. But just before the test started, they were informed that
because of a glitch in the computer it occasionally displayed the answer
by accident; if this happened, they were to click it away without
looking. Those who had read the deterministic message were more likely
to cheat on the test. "Perhaps, denying free will simply provides the
ultimate excuse to behave as one likes", Vohs and Schooler suggested.However, although initial studies suggested that believing in free will
is associated with more morally praiseworthy behavior, some recent
studies have reported contradictory findings.
Notable experiments
Libet Experiment
A pioneering experiment in this field was conducted by Benjamin Libet
in the 1980s, in which he asked each subject to choose a random moment
to flick their wrist while he measured the associated activity in their
brain (in particular, the build-up of electrical signal called the Bereitschaftspotential (BP), which was discovered by Kornhuber & Deecke in 1965). Although it was well known that the "readiness potential" (German: Bereitschaftspotential)
preceded the physical action, Libet asked how it corresponded to the
felt intention to move. To determine when the subjects felt the
intention to move, he asked them to watch the second hand of a clock and
report its position when they felt that they had felt the conscious
will to move.
Libet's experiment: (0) repose, until (1) the Bereitschaftspotential is detected, (2-Libet's W) the volunteer memorizes a dot position upon feeling their intention, and then (3) acts.
Libet found that the unconscious brain activity leading up to the conscious decision by the subject to flick their wrist began approximately half a second before the subject consciously felt that they had decided to move. Libet's findings suggest that decisions made by a subject are first
being made on an unconscious level and only afterward being translated
into a "conscious decision", and that the subject's belief that it
occurred at the behest of their will was only due to their retrospective
perspective on the event.
The interpretation of these findings has been criticized by Daniel Dennett,
who argues that people will have to shift their attention from their
intention to the clock, and that this introduces temporal mismatches
between the felt experience of will and the perceived position of the
clock hand. Consistent with this argument, subsequent studies have shown that the exact numerical value varies depending on attention. Despite the differences in the exact numerical value, however, the main finding has held. Philosopher Alfred Mele criticizes this design for other reasons.
Having attempted the experiment himself, Mele explains that "the
awareness of the intention to move" is an ambiguous feeling at best. For
this reason he remained skeptical of interpreting the subjects'
reported times for comparison with their Bereitschaftspotential.
Criticisms
Typical recording of the Bereitschaftspotential that was discovered by Kornhuber and Deecke in 1965).
Benjamin Libet investigated whether this neural activity corresponded
to the "felt intention" (or will) to move of experimental subjects.
In a variation of this task, Haggard and Eimer (1999) asked subjects
to decide not only when to move their hands, but also to decide which hand to move. In this case, the felt intention correlated much more closely with the "lateralized readiness potential" (LRP), an event-related potential
(ERP) component that measures the difference between left and right
hemisphere brain activity. Haggard and Eimer argue that the feeling of
conscious will must therefore follow the decision of which hand to move,
since the LRP reflects the decision to lift a particular hand.
A more direct test of the relationship between the Bereitschaftspotential
and the "awareness of the intention to move" was conducted by Banks and
Isham (2009). In their study, participants performed a variant of the
Libet's paradigm in which a delayed tone followed the button press.
Subsequently, research participants reported the time of their intention
to act (e.g., Libet's W). If W were time-locked to the Bereitschaftspotential, W would remain uninfluenced by any post-action information. However, findings from this study show that W in fact shifts systematically with the time of the tone presentation, implicating that W is, at least in part, retrospectively reconstructed rather than pre-determined by the Bereitschaftspotential.
A study conducted by Jeff Miller and Judy Trevena (2010) suggests that the Bereitschaftspotential
(BP) signal in Libet's experiments doesn't represent a decision to
move, but that it's merely a sign that the brain is 'paying attention'. In this experiment the classical Libet experiment was modified by
playing an audio tone indicating to volunteers to decide whether to tap a
key or not. The researchers found that there was the same RP signal in
both cases, regardless of whether or not volunteers actually elected to
tap, which suggests that the RP signal doesn't indicate that a decision
has been made.
In a second experiment, researchers asked volunteers to decide on
the spot whether to use left hand or right to tap the key while
monitoring their brain signals, and they found no correlation among the
signals and the chosen hand. This criticism has itself been criticized
by free-will researcher Patrick Haggard, who mentions literature that
distinguishes two different circuits in the brain that lead to action: a
"stimulus-response" circuit and a "voluntary" circuit. According to
Haggard, researchers applying external stimuli may not be testing the
proposed voluntary circuit, nor Libet's hypothesis about internally
triggered actions.
Libet's interpretation of the ramping up of brain activity prior
to the report of conscious "will" continues to draw heavy criticism.
Studies have questioned participants' ability to report the timing of
their "will". Authors have found that preSMA
activity is modulated by attention (attention precedes the movement
signal by 100 ms), and the prior activity reported could therefore have
been product of paying attention to the movement. They also found that the perceived onset of intention depends on neural
activity that takes place after the execution of action. Transcranial magnetic stimulation (TMS) applied over the preSMA
after a participant performed an action shifted the perceived onset of
the motor intention backward in time, and the perceived time of action
execution forward in time.
Others have speculated that the preceding neural activity
reported by Libet may be an artefact of averaging the time of "will",
wherein neural activity does not always precede reported "will". In a similar replication they also reported no difference in
electrophysiological signs before a decision not to move and before a
decision to move.
Benjamin Libet himself did not interpret his experiment as
evidence of the inefficacy of conscious free will — he points out that
although the tendency to press a button may be building up for 500
milliseconds, the conscious will retain a right to veto any action at
the last moment. According to this model, unconscious impulses to perform a volitional
act are open to suppression by the conscious efforts of the subject
(sometimes referred to as "free won't"). A comparison is made with a golfer,
who may swing a club several times before striking the ball. The action
simply gets a rubber stamp of approval at the last millisecond.
Some studies have replicated Libet's findings, whilst addressing some of the original criticisms. A 2011 study conducted by Itzhak Fried found with a greater than 80%
accuracy that individual neurons fire 700 ms before a reported "will" to
act (long before EEG activity predicted such a response). This was accomplished with the help of volunteer epilepsy patients, who needed electrodes
implanted deep in their brain for evaluation and treatment anyway. Now
able to monitor awake and moving patients, the researchers replicated
the timing anomalies that were discovered by Libet. Similarly to these tests, Chun Siong Soon, Anna Hanxi He, Stefan Bode and John-Dylan Haynes
have conducted a study in 2013 claiming to be able to predict by 4 s
the choice to sum or subtract before the subject reports it.
William R. Klemm pointed out the inconclusiveness of these tests
due to design limitations and data interpretations and proposed less
ambiguous experiments, while affirming a stand on the existence of free will, like Roy F. Baumeister, or Catholic neuroscientists such as Tadeusz Pacholczyk.
Adrian G. Guggisberg and Annaïs Mottaz have also challenged Libet and
Fried's findings, stating that "the instantaneous appearance of
conscious intentions might be an artifact of the method used for
assessing the contents of consciousness" and that "studies using
alternatives to the Libet clock have suggested that intention
consciousness is a multistage process just as the neural mechanisms of
motor decisions", concluding that "the time of conscious intentions
reported by the participants therefore might be only the culmination of
preceding conscious deliberations, not a unique and instantaneous event"
and "if this is true, the delay between the onset of neural predictors
of motor decisions and conscious intentions reported with the Libet
clock is not due to unconscious neural processes but due to conscious
evaluations which are not final yet".
Another criticism stems from the fact that, despite being treated
as the same by Libet, an urge, a wish and a desire are not the same
thing as an intention, a decision, and a choice.
In an empirical study in 2019, researchers found that readiness
potentials were absent for deliberate decisions, and preceded arbitrary
decisions only.
In a study published in 2012, Aaron Schurger, Jacobo D. Sitt, and Stanislas Dehaene published in Proceedings of the National Academy of Sciences of the United States of America
(PNAS), proposed that the occurrence of the readiness potentials
observed in Libet-type experiments is stochastically occasioned by
ongoing spontaneous subthreshold fluctuations in neural activity, rather
than an unconscious goal-directed operation,and challenged assumptions about the causal nature of the Bereitschaftspotential
itself (and the "pre-movement buildup" of neural activity in general
when faced with a choice), thus denying the conclusions drawn from
studies such as Libet's and Fried's. See The Information Philosopher, New Scientist, and The Atlantic, for commentary on this study.
Unconscious actions
Timing intentions compared to actions
A study by Masao Matsuhashi and Mark Hallett,
published in 2008, claims to have replicated Libet's findings without
relying on subjective report or clock memorization on the part of
participants. The authors believe that their method can identify the time (T) at which a subject becomes aware of his own movement. Matsuhashi and Hallet argue that T not only varies, but often occurs after early phases of movement genesis have already begun (as measured by the readiness potential). They conclude that a person's awareness cannot be the cause of movement, and may instead only notice the movement.
The experiment
Matsuhashi and Hallett's study can be summarized thus. The
researchers hypothesized that, if our conscious intentions are what
causes movement genesis (i.e. the start of an action), then naturally,
our conscious intentions should always occur before any movement has
begun. Otherwise, if we ever become aware of a movement only after it
has already been started, our awareness could not have been the cause of
that particular movement. Simply put, conscious intention must precede
action if it is its cause.
To test this hypothesis, Matsuhashi and Hallet had volunteers
perform brisk finger movements at random intervals, while not counting
or planning when to make such (future) movements, but rather immediately
making a movement as soon as they thought about it. An externally
controlled "stop-signal" sound was played at pseudo-random intervals,
and the volunteers had to cancel their intent to move if they heard a
signal while being aware of their own immediate intention to move.
Whenever there was an action (finger movement), the authors
documented (and graphed) any tones that occurred before that action. The
graph of tones before actions therefore only shows tones (a) before the
subject is even aware of his "movement genesis" (or else they would
have stopped or "vetoed" the movement), and (b) after it is too late to
veto the action. This second set of graphed tones is of little
importance here.
In this work, "movement genesis" is defined as the brain process
of making movement, of which physiological observations have been made
(via electrodes) indicating that it may occur before conscious awareness
of intent to move (see Benjamin Libet).
By looking to see when tones started preventing actions, the
researchers supposedly know the length of time (in seconds) that exists
between when a subject holds a conscious intention to move and performs
the action of movement. This moment of awareness is called T (the
mean time of conscious intention to move). It can be found by looking
at the border between tones and no tones. This enables the researchers
to estimate the timing of the conscious intention to move without
relying on the subject's knowledge or demanding them to focus on a
clock. The last step of the experiment is to compare time T for each subject with their event-related potential (ERP) measures (e.g., seen in this page's lead image), which reveal when their finger movement genesis first begins.
The researchers found that the time of the conscious intention to move T
normally occurred too late to be the cause of movement genesis. See the
example of a subject's graph below on the right. Although it is not
shown on the graph, the subject's readiness potentials (ERP) tells us
that his actions start at −2.8 seconds, and yet this is substantially
earlier than his conscious intention to move, time T
(−1.8 seconds). Matsuhashi and Hallet concluded that the feeling of the
conscious intention to move does not cause movement genesis; both the
feeling of intention and the movement itself are the result of
unconscious processing.
Analysis and interpretation
This study is similar to Libet's in some ways: volunteers were again
asked to perform finger extensions in short, self-paced intervals. In
this version of the experiment, researchers introduced randomly timed
"stop tones" during the self-paced movements. If participants were not
conscious of any intention to move, they simply ignored the tone. On the
other hand, if they were aware of their intention to move at the time
of the tone, they had to try to veto the action, then relax for a bit
before continuing self-paced movements. This experimental design allowed
Matsuhashi and Hallet to see when, once the subject moved his finger,
any tones occurred. The goal was to identify their own equivalent of
Libet's W, their own estimation of the timing of the conscious intention to move, which they would call T (time).
Testing the hypothesis that "conscious intention occurs after
movement genesis has already begun" required the researchers to analyse
the distribution of responses to tones before actions. The idea is that,
after time T, tones will lead to vetoing and thus a reduced representation in the data. There would also be a point of no return P
where a tone was too close to the movement onset for the movement to be
vetoed. In other words, the researchers were expecting to see the
following on the graph: many unsuppressed responses to tones while the
subjects are not yet aware of their movement genesis, followed by a drop
in the number of unsuppressed responses to tones during a certain
period of time during which the subjects are conscious of their
intentions and are stopping any movements, and finally a brief increase
again in unsuppressed responses to tones when the subjects do not have
the time to process the tone and prevent an action – they have passed
the action's "point of no return". That is exactly what the researchers
found (see the graph on the right, below).
Graphing
tones as they appeared (or didn't) in the time before any action. In
this case, researchers believe that the subject becomes aware of his
actions at about 1.8 seconds (this is time T). A typical subject's ERP recordings suggest movement preparation as early as −2.8 seconds.
The graph shows the times at which unsuppressed responses to tones
occurred when the volunteer moved. He showed many unsuppressed responses
to tones (called "tone events" on the graph) on average up until
1.8 seconds before movement onset, but a significant decrease in tone
events immediately after that time. Presumably this is because the
subject usually became aware of his intention to move at about
−1.8 seconds, which is then labelled point T. Since most actions are vetoed if a tone occurs after point T,
there are very few tone events represented during that range. Finally,
there is a sudden increase in the number of tone events at 0.1 seconds,
meaning that this subject has passed point P. Matsuhashi and Hallet were thus able to establish an average time T (−1.8 seconds) without subjective report. This, they compared to ERP measurements of movement, which had detected movement beginning at about −2.8 seconds on average for this participant. Since T, like Libet's original W,
was often found after movement genesis had already begun, the authors
concluded that the generation of awareness occurred afterwards or in
parallel to action, but most importantly, that it was probably not the
cause of the movement.
Criticisms
Haggard describes other studies at the neuronal levels as providing
"a reassuring confirmation of previous studies that recorded neural
populations" such as the one just described. Note that these results were gathered
using finger movements and may not necessarily generalize to other
actions such as thinking, or even other motor actions in different
situations. Indeed, the human act of planning
has implications for free will, and so this ability must also be
explained by any theories of unconscious decision-making. Philosopher
Alfred Mele also doubts the conclusions of these studies. He explains
that simply because a movement may have been initiated before our
"conscious self" has become aware of it does not mean that our
consciousness does not still get to approve, modify, and perhaps cancel
(called vetoing) the action.
A 2021 meta-analysis
of Libet-style studies found that while a pattern exists in which the
readiness potential precedes the conscious intention to act, the effect
is uncertain and based on only a small number of studies, indicating
that the evidence is weaker than often claimed.
Unconsciously cancelling actions
Retrospective judgement of free choice
Recent research by Simone Kühn and Marcel Brass suggests that
consciousness may not be what causes some actions to be vetoed at the
last moment. First of all, their experiment relies on the simple idea
that we ought to know when we consciously cancel an action (i.e. we
should have access to that information). Secondly, they suggest that
access to this information means humans should find it easy to
tell, just after completing an action, whether it was "impulsive" (there
being no time to decide) and when there was time to "deliberate" (the
participant decided to allow/not to veto the action). The study found
evidence that subjects could not tell this important difference. This
again leaves some conceptions of free will vulnerable to the introspection illusion.
The researchers interpret their results to mean that the decision to
"veto" an action is determined unconsciously, just as the initiation of
the action may have been unconscious in the first place.
The experiment
The experiment involved asking volunteers to respond to a go-signal
by pressing an electronic "go" button as quickly as possible. In this experiment the go-signal was represented as a visual stimulus
shown on a monitor. The participants' reaction times (RT) were gathered
at this stage, in what was described as the "primary response trials".
The primary response trials were then modified, in which 25% of
the go-signals were subsequently followed by an additional signal –
either a "stop" or "decide" signal. The additional signals occurred
after a "signal delay" (SD), a random amount of time up to 2 seconds
after the initial go-signal. They also occurred equally, each
representing 12.5% of experimental cases. These additional signals were
represented by the initial stimulus changing colour (e.g., to either a
red or orange light). The other 75% of go-signals were not followed by
an additional signal, and therefore considered the "default" mode of the
experiment. The participants' task of responding as quickly as possible
to the initial signal (i.e. pressing the "go" button) remained.
Upon seeing the initial go-signal, the participant would
immediately intend to press the "go" button. The participant was
instructed to cancel their immediate intention to press the "go" button
if they saw a stop signal. The participant was instructed to select
randomly (at their leisure) between either pressing the "go" button or
not pressing it, if they saw a decide signal. Those trials in which the
decide signal was shown after the initial go-signal ("decide trials"),
for example, required that the participants prevent themselves from
acting impulsively on the initial go-signal and then decide what to do.
Due to the varying delays, this was sometimes impossible (e.g., some
decide signals simply appeared too late in the process of them both intending to and pressing the go button for them to be obeyed).
Those trials in which the subject reacted to the go-signal
impulsively without seeing a subsequent signal show a quick RT of about
600 ms. Those trials in which the decide signal was shown too late, and
the participant had already enacted their impulse to press the go-button
(i.e. had not decided to do so), also show a quick RT of about 600 ms.
Those trials in which a stop signal was shown and the participant
successfully responded to it, do not show a response time. Those trials
in which a decide signal was shown, and the participant decided not to
press the go-button, also do not show a response time. Those trials in
which a decide signal was shown, and the participant had not already
enacted their impulse to press the go-button, but (in which it was
theorised that they) had had the opportunity to decide what to do, show a
comparatively slow RT, in this case closer to 1400 ms.
The participant was asked at the end of those "decide trials" in
which they had actually pressed the go-button whether they had acted
impulsively (without enough time to register the decide signal before
enacting their intent to press the go-button in response to the initial
go-signal stimulus) or based upon a conscious decision made after seeing
the decide signal. Based upon the response time data, however, it
appears that there was discrepancy between when the user thought that
they had had the opportunity to decide (and had therefore not acted on
their impulses) – in this case deciding to press the go-button, and when
they thought that they had acted impulsively (based upon the initial
go-signal) – where the decide signal came too late to be obeyed.
The rationale
Kühn and Brass wanted to test participant self-knowledge. The first
step was that after every decide trial, participants were next asked
whether they actually had time to decide. Specifically, the volunteers
were asked to label each decide trial as either failed-to-decide (the
action was the result of acting impulsively on the initial go-signal) or
successful decide (the result of a deliberated decision). See the
diagram on the right for this decide trial split: failed-to-decide and
successful decide; the next split in this diagram (participant correct
or incorrect) will be explained at the end of this experiment. Note also
that the researchers sorted the participants' successful decide trials
into "decide go" and "decide no-go", but were not concerned with the
no-go trials, since they did not yield any RT data (and are not featured
anywhere in the diagram on the right). Note that successful stop trials
did not yield RT data either.
The different types of trials and their different possible outcomes
Kühn and Brass now knew what to expect: primary response trials, any
failed stop trials, and the "failed-to-decide" trials were all instances
where the participant obviously acted impulsively – they would show the
same quick RT. In contrast, the "successful decide" trials
(where the decision was a "go" and the subject moved) should show a
slower RT. Presumably, if deciding whether to veto is a conscious
process, volunteers should have no trouble distinguishing impulsivity
from instances of true deliberate continuation of a movement. Again,
this is important, since decide trials require that participants rely on
self-knowledge. Note that stop trials cannot test self-knowledge
because if the subject does act, it is obvious to them that they reacted impulsively.
Results and implications
The
general distribution of reaction times for the different trials. Notice
the timing of the two peaks for trials labelled "successful decide".
Unsurprisingly, the recorded RTs for the primary response trials,
failed stop trials, and "failed-to-decide" trials all showed similar
RTs: 600 ms seems to indicate an impulsive action made without time to
truly deliberate. What the two researchers found next was not as easy to
explain: while some "successful decide" trials did show the tell-tale
slow RT of deliberation (averaging around 1400 ms), participants had
also labelled many impulsive actions as "successful decide". This result
is startling because participants should have had no trouble
identifying which actions were the results of a conscious "I will not
veto", and which actions were un-deliberated, impulsive reactions to the
initial go-signal. As the authors explain:
[The results of the experiment]
clearly argue against Libet's assumption that a veto process can be
consciously initiated. He used the veto in order to reintroduce the
possibility to control the unconsciously initiated actions. But since
the subjects are not very accurate in observing when they have [acted
impulsively instead of deliberately], the act of vetoing cannot be
consciously initiated.
In decide trials, the participants, it seems, were not able to
reliably identify whether they had really had time to decide;– at least,
not based on internal signals. The authors explain that this result is
difficult to reconcile with the idea of a conscious veto, but is simple
to understand if the veto is considered an unconscious process. Thus it seems that the intention to move might not only arise from the
unconscious mind, but it may only be inhibited if the unconscious mind
says so.
Criticisms
After the above experiments, the authors concluded that subjects
sometimes could not distinguish between "producing an action without
stopping and stopping an action before voluntarily resuming", or in
other words, they could not distinguish between actions that are
immediate and impulsive as opposed to delayed by deliberation. To be clear, one assumption of the authors is that all the early
(600 ms) actions are unconscious, and all the later actions are
conscious. These conclusions and assumptions have yet to be debated
within the scientific literature or even replicated (it is a very early
study).
The results of the trial in which the so-called "successful
decide" data (with its respective longer time measured) was observed may
have possible implications for our understanding of the role of consciousness as the modulator of a
given action or response, and these possible implications cannot merely
be omitted or ignored without valid reasons, especially when the
authors of the experiment suggest that the late decide trials were
actually deliberated.
It is worth noting that Libet consistently referred to a veto of an action that was initiated endogenously. That is, a veto that occurs in the absence of external cues, instead
relying on only internal cues (if any at all). This veto may be a
different type of veto than the one explored by Kühn and Brass using
their decide signal.
Daniel Dennett also argues that no clear conclusion about
volition can be derived from Benjamin Libet's experiments supposedly
demonstrating the irrelevance of conscious volition. According to
Dennett, ambiguities in the timings of the different events are
involved. Libet tells when the readiness potential occurs objectively,
using electrodes, but relies on the subject reporting the position of
the hand of a clock to determine when the conscious decision was made.
As Dennett points out, this is only a report of where it seems to the subject that various things come together, not of the objective time at which they actually occur:
Suppose Libet knows that your readiness potential peaked at
millisecond 6,810 of the experimental trial, and the clock dot was
straight down (which is what you reported you saw) at millisecond 7,005.
How many milliseconds should he have to add to this number to get the
time you were conscious of it? The light gets from your clock face to
your eyeball almost instantaneously, but the path of the signals from
retina through lateral geniculate nucleus to striate cortex takes 5 to
10 milliseconds — a paltry fraction of the 300 milliseconds offset, but
how much longer does it take them to get to you. (Or are you
located in the striate cortex?) The visual signals have to be processed
before they arrive at wherever they need to arrive for you to make a
conscious decision of simultaneity. Libet's method presupposes, in
short, that we can locate the intersection of two trajectories:
the rising-to-consciousness of signals representing the decision to flick
the rising to consciousness of signals representing successive clock-face orientations
so that these events occur side-by-side as it were in place where their simultaneity can be noted.
The point of no return
In early 2016, Proceedings of the National Academy of Sciences of the United States of America (PNAS) published an article by researchers in Berlin, Germany, The point of no return in vetoing self-initiated movements,
in which the authors set out to investigate whether human subjects had
the ability to veto an action (in this study, a movement of the foot)
after the detection of its Bereitschaftspotential (BP). The Bereitschaftspotential, which was discovered by Kornhuber & Deecke in 1965, is an instance of unconsciouselectrical activity within the motor cortex, quantified by the use of EEG,
that occurs moments before a motion is performed by a person: it is
considered a signal that the brain is "getting ready" to perform the
motion. The study found evidence that these actions can be vetoed even
after the BP is detected (i. e. after it can be seen that the brain has
started preparing for the action). The researchers maintain that this is
evidence for the existence of at least some degree of free will in
humans: previously, it had been argued that, given the unconscious nature of the BP and its usefulness in
predicting a person's movement, these are movements that are initiated
by the brain without the involvement of the conscious will of the
person. The study showed that subjects were able to "override" these signals
and stop short of performing the movement that was being anticipated by
the BP. Furthermore, researchers identified what was termed a "point of
no return": once the BP is detected for a movement, the person could
refrain from performing the movement only if they attempted to cancel it
at least 200 milliseconds before the onset of the movement. After this point, the person was unable to avoid performing the movement. Previously, Kornhuber and Deecke underlined that absence of conscious will during the early Bereitschaftspotential
(termed BP1) is not a proof of the non-existence of free will, as also
unconscious agendas may be free and non-deterministic. According to
their suggestion, man has relative freedom, i.e. freedom in degrees,
that can be increased or decreased through deliberate choices that
involve both conscious and unconscious (panencephalic) processes.
Neuronal prediction of free will
Despite criticisms, experimenters are still trying to gather data
that may support the case that conscious "will" can be predicted from
brain activity. fMRImachine learning
of brain activity (multivariate pattern analysis) has been used to
predict the user choice of a button (left/right) up to 7 seconds before
their reported will of having done so. Brain regions successfully trained for prediction included the frontopolar cortex (anteriormedialprefrontal cortex) and precuneus/posteriorcingulate cortex (medial parietal cortex).
In order to ensure report timing of conscious "will" to act, they
showed the participant a series of frames with single letters (500 ms
apart), and upon pressing the chosen button (left or right) they were
required to indicate which letter they had seen at the moment of
decision. This study reported a statistically significant 60% accuracy
rate, which may be limited by experimental setup; machine-learning data
limitations (time spent in fMRI) and instrument precision.
Another version of the fMRI multivariate pattern analysis
experiment was conducted using an abstract decision problem, in an
attempt to rule out the possibility of the prediction capabilities being
product of capturing a built-up motor urge. Each frame contained a central letter like before, but also a central
number, and 4 surrounding possible "answers numbers". The participant
first chose in their mind whether they wished to perform an addition or
subtraction operation, and noted the central letter on the screen at the
time of this decision. The participant then performed the mathematical
operation based on the central numbers shown in the next two frames. In
the following frame the participant then chose the "answer number"
corresponding to the result of the operation. They were further
presented with a frame that allowed them to indicate the central letter
appearing on the screen at the time of their original decision. This
version of the experiment discovered a brain prediction capacity of up
to 4 seconds before the conscious will to act.
Multivariate pattern analysis using EEG has suggested that an
evidence-based perceptual decision model may be applicable to free-will
decisions. It was found that decisions could be predicted by neural activity
immediately after stimulus perception. Furthermore, when the participant
was unable to determine the nature of the stimulus, the recent decision
history predicted the neural activity (decision). The starting point of
evidence accumulation was in effect shifted towards a previous choice
(suggesting a priming bias). Another study has found that subliminally
priming a participant for a particular decision outcome (showing a cue
for 13 ms) could be used to influence free decision outcomes. Likewise, it has been found that decision history alone can be used to
predict future decisions. The prediction capacities of the Chun Siong
Soon et al. (2008) experiment were successfully replicated using a
linear SVM model based on participant decision history alone (without
any brain activity data). Despite this, a recent study has sought to confirm the applicability of a perceptual decision model to free will decisions. When shown a masked and therefore invisible stimulus, participants were
asked to either guess between a category or make a free decision for a
particular category. Multivariate pattern analysis using fMRI could be
trained on "free-decision" data to successfully predict "guess
decisions", and trained on "guess data" in order to predict "free
decisions" (in the precuneus and cuneus region).
Criticisms
Contemporary voluntary decision prediction tasks have been criticised
based on the possibility the neuronal signatures for pre-conscious
decisions could actually correspond to lower-conscious processing rather
than unconscious processing. People may be aware of their decisions before making their report, yet
need to wait several seconds to be certain. However, such a model does
not explain what is left unconscious if everything can be conscious at
some level (and the purpose of defining separate systems). Yet
limitations remain in free-will prediction research to date. In
particular, the prediction of considered judgements from brain activity
involving thought processes beginning minutes rather than seconds before
a conscious will to act, including the rejection of a conflicting
desire. Such are generally seen to be the product of sequences of
evidence accumulating judgements.
Other related phenomena
Retrospective construction
It has been suggested that sense authorship is an illusion. Unconscious causes of thought and action might facilitate thought and
action, while the agent experiences the thoughts and actions as being
dependent on conscious will. The idea behind retrospective construction
is that, while part of the "yes, I did it" feeling of agency
seems to occur during action, there also seems to be processing
performed after the fact – after the action is performed – to establish
the full feeling of agency. However, to assign agency, one does not have to believe that agency is free.
In the moment, unconscious agency processing can alter how we perceive the timing of sensations or actions.Kühn and Brass apply retrospective construction to explain the two
peaks in "successful decide" RTs. They suggest that the late decide
trials were actually deliberated, but that the impulsive early decide
trials that should have been labelled "failed-to-decide" were mistaken
during unconscious agency processing. They say that people "persist in
believing that they have access to their own cognitive processes" when
in fact we do a great deal of automatic unconscious processing before
conscious perception occurs.
Criticisms
Criticism to Daniel Wegner's claims regarding the significance of introspection illusion for the notion of free will has been published.
Some research suggests that TMS can be used to manipulate the perception of authorship of a specific choice. Experiments showed that neurostimulation could affect which hands
people move, even though the subjective experience of will was intact.
An early TMS study revealed that activation of one side of the neocortex could be used to bias the selection of one's opposite side hand in a forced-choice decision task. K. Ammon and S. C. Gandevia found that it was possible to influence which hand people move by stimulating frontal regions that are involved in movement planning using transcranial magnetic stimulation in the left or right hemisphere of the brain.
Right-handed people would normally choose to move their right
hand 60% of the time, but when the right hemisphere was stimulated, they
would instead choose their left hand 80% of the time (recall that the
right hemisphere of the brain is responsible for the left side of the
body, and the left hemisphere for the right). Despite the external
influence on their decision-making, the subjects were apparently unaware
of any influence, as when questioned they felt that their decisions
appeared to be made in an entirely natural way. In a follow-up experiment, Alvaro Pascual-Leone
and colleagues found similar results, but also noted that the
transcranial magnetic stimulation must occur within the motor area and
within 200 milliseconds, consistent with the time-course derived from
the Libet experiments: with longer response times (between 200 and 1100
ms), magnetic stimulation had no effect on hand preference regardless of
the site stimulated.
In late 2015, following a previous 2010 study, both based on earlier investigations on both monkeys and humans, a team
of researchers from the UK and the US published an article
demonstrating similar findings. The researchers concluded that "motor
responses and the choice of hand can be modulated using tDCS". However, a different attempt by Y. H. Sohn et al. failed to replicate such results.
Manipulating the perceived intention to move
Various studies indicate that the perceived intention to move (have moved) can be manipulated. Studies have focused on the pre-supplementary motor area
(pre-SMA) of the brain, in which readiness potential indicating the
beginning of a movement genesis has been recorded by EEG. In one study,
directly stimulating the pre-SMA caused volunteers to report a feeling
of intention, and sufficient stimulation of that same area caused
physical movement. In a similar study, it was found that people with no visual awareness
of their body can have their limbs be made to move without having any
awareness of this movement, by stimulating premotor
brain regions. When their parietal cortices were stimulated, they
reported an urge (intention) to move a specific limb (that they wanted
to do so). Furthermore, stronger stimulation of the parietal cortex
resulted in the illusion of having moved without having done so.
This suggests that awareness of an intention to move may
literally be the "sensation" of the body's early movement, but certainly
not the cause. Other studies have at least suggested that "The greater
activation of the SMA, SACC, and parietal areas during and after
execution of internally generated actions suggests that an important
feature of internal decisions is specific neural processing taking place
during and after the corresponding action. Therefore, awareness of
intention timing seems to be fully established only after execution of
the corresponding action, in agreement with the time course of neural
activity observed here."
Another experiment involved an electronic ouija
board where the device's movements were manipulated by the
experimenter, while the participant was led to believe that they were
entirely self-conducted. The experimenter stopped the device on occasions and asked the
participant how much they themselves felt like they wanted to stop. The
participant also listened to words in headphones, and it was found that
if experimenter stopped next to an object that came through the
headphones, they were more likely to say that they wanted to stop there.
If the participant perceived having the thought at the time of the
action, then it was assigned as intentional. It was concluded that a
strong illusion of perception of causality requires: priority (we assume
the thought must precede the action), consistency (the thought is about
the action), and exclusivity (no other apparent causes or alternative
hypotheses).
Hakwan C. Lau et al. set up an experiment where subjects would
look at an analog-style clock, and a red dot would move around the
screen. Subjects were told to click the mouse button whenever they felt
the intention to do so. One group was given a transcranial magnetic stimulation
(TMS) pulse, and the other was given a sham TMS. Subjects in the
perceived intention condition were told to move the cursor to where it
was when they felt the inclination to press the button. In the movement
condition, subjects moved their cursor to where it was when they
physically pressed the button. TMS applied over the pre-SMA after a
participant performed an action shifted the perceived onset of the motor
intention backward in time, and the perceived time of action execution
forward in time. Results showed that the TMS was able to shift the
perceived intention condition forward by 16 ms, and shifted back by
14 ms for the movement condition. Perceived intention could be
manipulated up to 200 ms after the execution of the spontaneous action,
indicating that the perception of intention occurred after the executive
motor movements. The results of three control studies suggest that this
effect is time-limited, specific to modality, and also specific to the
anatomical site of stimulation. The investigators conclude that the
perceived onset of intention depends, at least in part, on neural
activity that takes place after the execution of action. Often it is thought that if free will were to exist, it would require
intention to be the causal source of behavior. These results show that
intention may not be the causal source of all behavior.
Related models
The idea that intention co-occurs with (rather than causes) movement
is reminiscent of "forward models of motor control" (FMMC), which have
been used to try to explain inner speech.
FMMCs describe parallel circuits: movement is processed in parallel
with other predictions of movement; if the movement matches the
prediction, the feeling of agency occurs. FMMCs have been applied in
other related experiments. Janet Metcalfe and her colleagues used an
FMMC to explain how volunteers determine whether they are in control of a
computer game task. On the other hand, they acknowledge other factors
as well. The authors attribute feelings of agency to desirability of the
results (see self-serving biases) and top-down processing (reasoning and inferences about the situation).
There is also a model, called epiphenomenalism, that argues that conscious will is an illusion, and that consciousness is a by-product of physical states of the world. Others have argued that data such as the Bereitschaftspotential
undermine epiphenomenalism for the same reason, that such experiments
rely on a subject reporting the point in time at which a conscious
experience and a conscious decision occurs, thus relying on the subject
to be able to consciously perform an action. That ability would seem to
be at odds with epiphenomenalism, which, according to Thomas Henry Huxley, is the broad claim that consciousness is "completely without any power… as the steam-whistle which accompanies the work of a locomotive engine is without influence upon its machinery".
Related brain disorders
Various brain disorders implicate the role of unconscious brain processes in decision-making tasks. Auditory hallucinations produced by schizophrenia seem to suggest a divergence of will and behaviour. The left brain of people whose hemispheres have been disconnected has
been observed to invent explanations for body movement initiated by the
opposing (right) hemisphere, perhaps based on the assumption that their
actions are consciously willed. Likewise, people with "alien hand syndrome" are known to conduct complex motor movements against their will.
Neural models of voluntary action
A neural model for voluntary action proposed by Haggard comprises two major circuits. The first involving early preparatory signals (basal gangliasubstantia nigra and striatum), prior intention and deliberation (medial prefrontal cortex), motor preparation/readiness potential (preSMA and SMA), and motor execution (primary motor cortex, spinal cord and muscles). The second involving the parietal-pre-motor circuit for object-guided actions, for example grasping (premotor cortex, primary motor cortex, primary somatosensory cortex, parietal cortex, and back to the premotor cortex).
He proposed that voluntary action involves external environment input
("when decision"), motivations/reasons for actions (early "whether
decision"), task and action selection ("what decision"), a final
predictive check (late "whether decision") and action execution.
Another neural model for voluntary action also involves what, when, and whether (WWW) based decisions. The "what" component of decisions is considered a function of the anterior cingulate cortex, which is involved in conflict monitoring. The timing ("when") of the decisions are considered a function of the preSMA and SMA, which is involved in motor preparation. Finally, the "whether" component is considered a function of the dorsal medial prefrontal cortex.
Martin Seligman
and others criticize the classical approach in science that views
animals and humans as "driven by the past" and suggest instead that
people and animals draw on experience to evaluate prospects they face
and act accordingly. The claim is made that this purposive action
includes evaluation of possibilities that have never occurred before and
is experimentally verifiable.
Seligman and others argue that free will and the role of
subjectivity in consciousness can be better understood by taking such a
"prospective" stance on cognition and that "accumulating evidence in a
wide range of research suggests [this] shift in framework".