Ideasthesia

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Ideasthesia 

 

Example of associations between graphemes and colors that are described more accurately as ideasthesia than as synesthesia

Ideasthesia (alternative spelling ideaesthesia) is a neuroscientific phenomenon in which activations of concepts (inducers) evoke perception-like sensory experiences (concurrents). The name comes from the Ancient Greek ἰδέα (idéa) and αἴσθησις (aísthēsis), meaning "sensing concepts" or "sensing ideas". The notion was introduced by neuroscientist Danko Nikolić as an alternative explanation for a set of phenomena traditionally covered by synesthesia.

While "synesthesia" meaning "union of senses" implies the association of two sensory elements with little connection to the cognitive level, empirical evidence indicated that most phenomena linked to synesthesia are in fact induced by semantic representations. That is, the linguistic meaning of the stimulus is what is important rather than its sensory properties. In other words, while synesthesia presumes that both the trigger (inducer) and the resulting experience (concurrent) are of sensory nature, ideasthesia presumes that only the resulting experience is of sensory nature while the trigger is semantic.

Research have later extended the concept to topics other than synesthesia and as it turned out applicable to everyday perception the concept have developed into a theory of how we perceive. For example ideasthesia has been applied to the theory of art and could bear important implications in explaining human conscious experience, which, according to ideasthesia, is grounded in how we activate concepts.

Examples and evidence

A drawing by a synesthete which illustrates time unit-space synesthesia/ideasthesia. The months in a year are organized into a circle surrounding the synesthete's body, each month having a fixed location in space and a unique color.

A common example of synesthesia is the association between graphemes and colors, usually referred to as grapheme-color synesthesia. Here, letters of the alphabet are associated with vivid experiences of color. Studies have indicated that the perceived color is context-dependent and is determined by the extracted meaning of a stimulus. For example, an ambiguous stimulus '5' that can be interpreted either as 'S' or '5' will have the color associated with 'S' or with '5', depending on the context in which it is presented. If presented among numbers, it will be interpreted as '5' and will associate the respective color. If presented among letters, it will be interpreted as 'S' and will associate the respective synesthetic color.

Evidence for grapheme-color synesthesia comes also from the finding that colors can be flexibly associated to graphemes, as new meanings become assigned to those graphemes. In one study synesthetes were presented with Glagolitic letters that they have never seen before, and the meaning was acquired through a short writing exercise. The Glagolitic graphemes inherited the colors of the corresponding Latin graphemes as soon as the Glagolitic graphemes acquired the new meaning.

In another study, synesthetes were prompted to form novel synesthetic associations to graphemes never seen before. Synesthetes created those associations within minutes or seconds - which was time too short to account for creation of new physical connections between color representation and grapheme representation areas in the brain, pointing again towards ideasthesia. Although the time course is consistent with postsynaptic AMPA receptor upregulation and/or NMDA receptor coactivation, which would imply that the realtime experience is invoked at the synaptic level of analysis prior to establishment of novel wiring per se, a very intuitively appealing model.

For lexical-gustatory synesthesia evidence also points towards ideasthesia: In lexical-gustatory synesthesia, verbalisation of the stimulus is not necessary for the experience of concurrents. Instead, it is sufficient to activate the concept.

Another case of synesthesia is swimming-style synesthesia in which each swimming style is associated with a vivid experience of a color. These synesthetes do not need to perform the actual movements of a corresponding swimming style. To activate the concurrent experiences, it is sufficient to activate the concept of a swimming style (e.g., by presenting a photograph of a swimmer or simply talking about swimming).

It has been argued that grapheme-color synesthesia for geminate consonants also provides evidence for ideasthesia.

In pitch-color synesthesia, the same tone will be associated with different colors depending on how it has been named; do-sharp (i.e. di) will have colors similar to do (e.g., a reddish color) and re-flat (i.e. ra) will have color similar to that of re (e.g., yellowish), although the two classes refer to the same tone. Similar semantic associations have been found between the acoustic characteristics of vowels and the notion of size.

One-shot synesthesia: There are synesthetic experiences that can occur just once in a lifetime, and are thus dubbed one-shot synesthesia. Investigation of such cases has indicated that such unique experiences typically occur when a synesthete is involved in an intensive mental and emotional activity such as making important plans for one's future or reflecting on one's life. It has been thus concluded that this is also a form of ideasthesia.

In normal perception

Which one would be called Bouba and which Kiki? Responses are highly consistent among people. This is an example of ideasthesia as the conceptualization of the stimulus plays an important role.

Over the past decade, it has been suggested that the Bouba/Kiki phenomenon is a case of ideasthesia. Most people will agree that the star-shaped object on the left is named Kiki and the round one on the right Bouba. It has been assumed that these associations come from direct connections between visual and auditory cortices. For example, according to that hypothesis, representations of sharp inflections in the star-shaped object would be physically connected to the representations of sharp inflection in the sound of Kiki. However, Gomez et al. have shown that Kiki/Bouba associations are much richer as either word and either image is associated semantically to a number of concepts such as white or black color, feminine vs. masculine, cold vs. hot, and others. These sound-shape associations seem to be related through a large overlap between semantic networks of Kiki and star-shape on one hand, and Bouba and round-shape on the other hand. For example, both Kiki and star-shape are clever, small, thin and nervous. This indicates that behind Kiki-Bouba effect lies a rich semantic network. In other words, our sensory experience is largely determined by the meaning that we assign to stimuli. Food description and wine tasting is another domain in which ideasthetic association between flavor and other modalities such as shape may play an important role. These semantic-like relations play a role in successful marketing; the name of a product should match its other characteristics.

Implications for development of synesthesia

The concept of ideasthesia bears implications for understanding how synesthesia develops in children. Synesthetic children may associate concrete sensory-like experiences primarily to the abstract concepts that they have otherwise difficulties dealing with. Synesthesia may thus be used as a cognitive tool to cope with the abstractness of the learning materials imposed by the educational system — referred to also as a "semantic vacuum hypothesis". This hypothesis explains why the most common inducers in synesthesia are graphemes and time units — both relating to the first truly abstract ideas that a child needs to master.

Implications for art theory

The concept of ideasthesia has been often discussed in relation to art, and also used to formulate a psychological theory of art. According to the theory, we consider something to be a piece of art when experiences induced by the piece are accurately balanced with semantics induced by the same piece. Thus, a piece of art makes us both strongly think and strongly experience. Moreover, the two must be perfectly balanced such that the most salient stimulus or event is both the one that evokes strongest experiences (fear, joy, ... ) and strongest cognition (recall, memory, ...) — in other words, idea is well balanced with aesthesia.

Ideasthesia theory of art may be used for psychological studies of aesthetics. It may also help explain classificatory disputes about art as its main tenet is that experience of art can only be individual, depending on person's unique knowledge, experiences and history. There could exist no general classification of art satisfactorily applicable to each and all individuals.

Neurophysiology of ideasthesia

Ideasthesia is congruent with the theory of brain functioning known as practopoiesis. According to that theory, concepts are not an emergent property of highly developed, specialized neuronal networks in the brain, as is usually assumed; rather, concepts are proposed to be fundamental to the very adaptive principles by which living systems and the brain operate.

A study using magnetoencephalography has shown that the information on synesthetic colors is available in the brain signals only about 200 milliseconds after the stimulus, which is consistent with conceptual mediation. The study supports the idea that synesthesia is a semantic phenomenon—i.e., ideasthesia.

Explanatory gap

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Explanatory_gap 

In philosophy of mind and consciousness, the explanatory gap is the difficulty that physicalist theories have in explaining how physical properties give rise to the way things feel when they are experienced. It is a term introduced by philosopher Joseph Levine. In the 1983 paper in which he first used the term, he used as an example the sentence, "Pain is the firing of C fibers", pointing out that while it might be valid in a physiological sense, it does not help us to understand how pain feels.

The explanatory gap has vexed and intrigued philosophers and AI researchers alike for decades and caused considerable debate. Bridging this gap (that is, finding a satisfying mechanistic explanation for experience and qualia) is known as "the hard problem".

To take an example of a phenomenon in which there is no gap, a modern computer's behavior can be adequately explained by its physical components alone, such as its circuitry and software.In contrast, it is thought by many mind-body dualists (e.g. René Descartes, David Chalmers) that subjective conscious experience constitutes a separate effect that demands another cause that is either outside the physical world (dualism) or due to an as yet unknown physical phenomenon (see for instance quantum mind, indirect realism).

Proponents of dualism claim that the mind is substantially and qualitatively different from the brain and that the existence of something metaphysically extra-physical is required to "fill the gap". Similarly, some argue that there are further facts—facts that do not follow logically from the physical facts of the world—about conscious experience. For example, they argue that what it is like to experience seeing red does not follow logically from the physical facts of the world.

Implications

The nature of the explanatory gap has been the subject of some debate. For example, some consider it to simply be a limit on our current explanatory ability. They argue that future findings in neuroscience or future work from philosophers could close the gap. However, others have taken a stronger position and argued that the gap is a definite limit on our cognitive abilities as humans—no amount of further information will allow us to close it. There has also been no consensus regarding what metaphysical conclusions the existence of the gap provides. Those wishing to use its existence to support dualism have often taken the position that an epistemic gap—particularly if it is a definite limit on our cognitive abilities—necessarily entails a metaphysical gap.

Levine and others have wished to either remain silent on the matter or argue that no such metaphysical conclusion should be drawn. He agrees that conceivability (as used in the Zombie and inverted spectrum arguments) is flawed as a means of establishing metaphysical realities; but he points out that even if we come to the metaphysical conclusion that qualia are physical, they still present an explanatory problem.

While I think this materialist response is right in the end, it does not suffice to put the mind-body problem to rest. Even if conceivability considerations do not establish that the mind is in fact distinct from the body, or that mental properties are metaphysically irreducible to physical properties, still they do demonstrate that we lack an explanation of the mental in terms of the physical.

However, such an epistemological or explanatory problem might indicate an underlying metaphysical issue—the non-physicality of qualia, even if not proven by conceivability arguments is far from ruled out.

In the end, we are right back where we started. The explanatory gap argument doesn't demonstrate a gap in nature, but a gap in our understanding of nature. Of course a plausible explanation for there being a gap in our understanding of nature is that there is a genuine gap in nature. But so long as we have countervailing reasons for doubting the latter, we have to look elsewhere for an explanation of the former.

At the core of the problem, according to Levine, is our lack of understanding of what it means for a qualitative experience to be fully comprehended. He emphasizes that we don't even know to what extent it is appropriate to inquire into the nature of this kind of experience. He uses the laws of gravity as an example, which laws seem to explain gravity completely yet do not account for the gravitational constant. Similarly to the way in which gravity appears to be an inexplicable brute fact of nature, the case of qualia may be one in which we are either lacking essential information or in which we're exploring a natural phenomenon that simply is not further apprehensible. Levine suggests that, as qualitative experience of a physical or functional state may simply be such a brute fact, perhaps we should consider whether or not it is really necessary to find a more complete explanation of qualitative experience.

Levine points out that the solution to the problem of understanding how much there is to be known about qualitative experience seems even more difficult because we also lack a way to articulate what it means for actualities to be knowable in the manner that he has in mind. He does conclude that there are good reasons why we wish for a more complete explanation of qualitative experiences. One very significant reason is that consciousness appears to only manifest where mentality is demonstrated in physical systems that are quite highly organized. This, of course, may be indicative of a human capacity for reasoning that is no more than the result of organized functions. Levine expresses that it seems counterintuitive to accept this implication that the human brain, so highly organized as it is, could be no more than a routine executor. He notes that although, at minimum, Materialism appears to entail reducibility of anything that is not physically primary to an explanation of its dependence on a mechanism that can be described in terms of physical fundamentals, that kind of reductionism doesn't attempt to reduce psychology to physical science. However, it still entails that there are inexplicable classes of facts which are not treated as relevant to statements pertinent to psychology.