A 16th century woodcut of Archimedes' eureka moment
The eureka effect (also known as the Aha! moment or eureka moment)
refers to the common human experience of suddenly understanding a
previously incomprehensible problem or concept. Some research describes
the Aha! effect (also known as insight or epiphany) as a memory advantage,
but conflicting results exist as to where exactly it occurs in the
brain, and it is difficult to predict under what circumstances one can
predict an Aha! moment
Insight is a psychological term that attempts to describe the
process in problem solving when a previously unsolvable puzzle becomes
suddenly clear and obvious. Often this transition from not understanding
to spontaneous comprehension is accompanied by an exclamation of joy or
satisfaction, an Aha! moment. A person utilizing insight to solve a
problem is able to give accurate, discrete, all-or-nothing type
responses, whereas individuals not using the insight process are more
likely to produce partial, incomplete responses.
A recent theoretical account of the Aha! moment started with four
defining attributes of this experience. First, the Aha! moment appears
suddenly; second, the solution to a problem can be processed smoothly,
or fluently; third, the Aha! moment elicits positive affect; fourth, a
person experiencing the Aha! moment is convinced that a solution is
true. These four attributes are not separate but can be combined because
the experience of processing fluency, especially when it occurs surprisingly (for example, because it is sudden), elicits both positive affect and judged truth.
Insight can be conceptualized as a two phase process. The first
phase of an Aha! experience requires the problem solver to come upon an
impasse, where they become stuck and even though they may seemingly have
explored all the possibilities, are still unable to retrieve or
generate a solution. The second phase occurs suddenly and unexpectedly.
After a break in mental fixation or re-evaluating the problem, the
answer is retrieved.
Some research suggest that insight problems are difficult to solve
because of our mental fixation on the inappropriate aspects of the
problem content. In order to solve insight problems, one must "think outside the box".
It is this elaborate rehearsal that may cause people to have better
memory for Aha! moments. Insight is believed to occur with a break in
mental fixation, allowing the solution to appear transparent and
obvious.
History and etymology
The effect is named from a story about the ancient Greek polymath Archimedes.
In the story, Archimedes was asked (c. 250 BC) by the local king to
determine whether a crown was pure gold. During a subsequent trip to a
public bath, Archimedes noted that water was displaced when his body
sank into the bath, and particularly that the volume
of water displaced equaled the volume of his body immersed in the
water. Having discovered how to measure the volume of an irregular
object, and conceiving of a method to solve the king's problem,
Archimedes allegedly leaped out and ran home naked, shouting "eureka" (I
have found it). This story is now thought to be fictional, because it
was first mentioned by the Roman writer Vitruvius nearly 200 years after the date of the alleged event, and because the method described by Vitruvius would not have worked. However, Archimedes certainly did important, original work in hydrostatics, notably in his On Floating Bodies.
Research
Initial research
Research
on the Aha! moment dates back more than 100 years, to the Gestalt
psychologists' first experiments on chimpanzee cognition. In his 1921 book, Wolfgang Köhler
described the first instance of insightful thinking in animals: One of
his chimpanzees, Sultan, was presented with the task of reaching a
banana that had been strung up high on the ceiling so that it was
impossible to reach by jumping. After several failed attempts to reach
the banana, Sultan sulked in the corner for a while, then suddenly
jumped up and stacked a few boxes upon each other, climbed them and thus
was able to grab the banana. This observation was interpreted as
insightful thinking. Köhler's work was continued by Karl Duncker and Max Wertheimer.
The Eureka effect was later also described by Pamela Auble,
Jeffrey Franks and Salvatore Soraci in 1979. The subject would be
presented with an initially confusing sentence such as "The haystack was
important because the cloth ripped". After a certain period of time of
non-comprehension by the reader, the cue word (parachute) would be
presented, the reader could comprehend the sentence, and this resulted
in better recall on memory tests.
Subjects spend a considerable amount of time attempting to solve the
problem, and initially it was hypothesized that elaboration towards
comprehension may play a role in increased recall. There was no evidence
that elaboration had any effect for recall. It was found that both
"easy" and "hard" sentences that resulted in an Aha! effect had
significantly better recall rates than sentences that subjects were able
to comprehend immediately. In fact equal recall rates were obtained for
both "easy" and "hard" sentences which were initially
non-comprehensible. It seems to be this non-comprehension to comprehension
which results in better recall. The essence of the aha feeling
underling insight problem solving was systemically empirically
investigated by Danek et al. and Shen and his colleagues.
How people solve insight problems
Currently there are two theories for how people arrive at the solution for insight problems. The first is the progress monitoring theory.
The person will analyze the distance from their current state to the
goal state. Once a person realizes that they cannot solve the problem
while on their current path, they will seek alternative solutions. In
insight problems this usually occurs late in the puzzle. The second way
that people attempt to solve these puzzles is the representational change theory.
The problem solver initially has a low probability for success because
they use inappropriate knowledge as they set unnecessary constraints on
the problem. Once the person relaxes his or her constraints, they can
bring previously unavailable knowledge into working memory to solve the
problem. The person also utilizes chunk
decomposition, where he or she will separate meaningful chunks into
their component pieces. Both constraint relaxation and chunk
decomposition allow for a change in representation, that is, a change in
the distribution of activation across working memory, at which point
they may exclaim, "Aha!" Currently both theories have support, with the
progress monitoring theory being more suited to multiple step problems,
and the representational change theory more suited to single step
problems.
The Eureka effect on memory occurs only when there is an initial confusion.
When subjects were presented with a clue word before the confusing
sentence was presented, there was no effect on recall. If the clue was
provided after the sentence was presented, an increase in recall
occurred.
Memory
It had
been determined that recall is greater for items that were generated by
the subject versus if the subject was presented with the stimuli.
There seems to be a memory advantage for instances where people are
able to produce an answer themselves, recall was higher when Aha!
reactions occurred.
They tested sentences that were initially hard to understand, but when
presented with a cued word, the comprehension became more apparent.
Other evidence was found indicating that effort in processing visual
stimuli was recalled more frequently than the stimuli that were simply
presented.
This study was done using connect-the-dots or verbal instruction to
produce either a nonsense or real image. It is believed that effort made
to comprehend something when encoding induces activation of alternative
cues that later participate in recall.
Cerebral lateralization
Functional magnetic resonance imaging and electroencephalogram studies have found that problem solving requiring insight involves increased activity in the right cerebral hemisphere
as compared with problem solving not requiring insight. In particular,
increased activity was found in the right hemisphere anterior superior temporal gyrus.
Sleep
Some
unconscious processing may take place while a person is asleep, and
there are several cases of scientific discoveries coming to people in
their dreams. Friedrich August Kekulé von Stradonitz said that the ring structure of benzene came to him in a dream where a snake was eating its own tail.
Studies have shown increased performance at insight problems if the
subjects slept during a break between receiving the problem and solving
it. Sleep may function to restructure problems, and allow new insights
to be reached. Henri Poincaré stated that he valued sleep as a time for "unconscious thought" that helped him break through problems.
Other theories
Professor Stellan Ohlsson
believes that at the beginning of the problem-solving process, some
salient features of the problem are incorporated into a mental
representation of the problem. In the first step of solving the problem,
it is considered in the light of previous experience. Eventually, an impasse
is reached, where all approaches to the problem have failed, and the
person becomes frustrated. Ohlsson believes that this impasse drives
unconscious processes which change the mental representation of a
problem, and cause novel solutions to occur.
General procedure for conducting ERP and EEG studies
When studying insight, or the Aha! effect, ERP or EEG
general methods are used. Initially a baseline measurement is taken,
which generally asks the subject to simply remember an answer to a
question. Following this, subjects are asked to focus on the screen
while a logogriph
is shown, and then they are given time with a blank screen to get the
answer, once they do they are required to press a key. After which the
answer appears on the screen. The subjects are then asked to press one
key to indicate that they thought of the correct answer and another to
indicate if they got the answer wrong, finally, not to press a key at
all if they were unsure or did not know the answer.
Evidence in EEG studies
Resting-state
neural activity has a standing influence on cognitive strategies used
when solving problems, particularly in the case of deriving solutions by
methodical search or by sudden insight.[3]
The two cognitive strategies used involve both search and analysis of
current state of a problem, to the goal state of that problem, while
insight problems are a sudden awareness of the solution to a problem.
Subjects studied were first recorded on the base-line resting
state of thinking. After being tested using the method described in the General Procedure for Conducting ERP and EEG Studies,
the ratio of insight versus non-insight solution were made to determine
whether an individual is classified as a high insight (HI) or a low
insight (LI) individual. Discriminating between HI and LI individuals
were important as both groups use different cognitive strategies to
solve anagram problems used in this study. Right hemisphere activation is believed to be involved in Aha! effects,
so it comes as no surprise that HI individuals would show greater
activation in the right hemisphere than the left hemisphere when
compared to the LI individuals. Evidence was found to support this idea,
there was greater activation in HI subjects at the right dorsal-frontal
(low-alpha band), right inferior-frontal (beta and gamma bands) and the
right parietal (gamma band) areas. As for LI subjects, left inferior-frontal and left anterior-temporal areas were active (low-alpha band).
There were also differences in attention between individuals of
HI and LI. It has been suggested that individuals who are highly
creative exhibit diffuse attention, thus allowing them a greater range
of environmental stimuli.
It was found that individuals who displayed HI would have less resting
state occipital alpha-band activity, meaning there would be less
inhibition of the visual system. Individuals that were less creative were found to focus their attention, thus causing them to sample less of their environment. Although, LI individuals were shown to have more occipital beta activity, consistent with heightened focused attention.
Evidence in ERP studies
These results are more reflective of models, rather than empirical evidence,
as source localization is hard to determine precisely.
Due to the nature of these studies that use Chinese logographs, there is
a difficulty in an exact translation; a language barrier certainly
exists.
There are some difficulties that exist in brain imaging when it
comes to insight, thus making it hard to discuss neural mechanisms.
Issues include: that insight occurs when an unwarranted mental fixation
is broken and when novel task related associations are formed on top of
old cognitive skills.
One theory discussed found that "Aha" answers produced more negative ERP results, N380 in the ACC, than the "No-Aha" answers, 250–500 ms, after an answer was produced. The authors suspected that this N380 in the ACC,
which plays the role of a warning sign of breaking the mental set, was a
reflection of the Aha! effect. Another study was done showed that an
Aha! effect was elicited at N320 which has a strong activation in the
central-posterior region. These previous studies reflective the premise of the study, that the Aha! effect occurs in the anterior cingulate cortex, while this study finds results indicating the posterior cingulate cortex is responsible. It was found that there was a N350 in the posterior cingulate cortex for successful guessing of logographs, not in the anterior cingulate cortex. The posterior cingulate cortex seems to play a more non-executive function in monitoring and inhibiting the mind set and cognitive function.
Another significant finding of this study done by Qiu and Zhang
(2008), was a late positive component (LPC) in successful guessing of
the logograph and then recognition of the answer at 600 and 700 ms,
post-stimulus, in the parahippocampal gyrus (BA34). The data suggests that the parahippocampus
is involved in searching of a correct answer by manipulating it in
working memory, and integrating relationships between the base of the
target logograph. The parahippocampal gyrus may reflect the formation of
novel associations while solving insight problem.
Another ERP study is fairly similar to the Qiu and Zhang, 2008 study, however, this study claims to have anterior cingulate cortex activation at N380, which may be responsible for the mediation of breaking the mental set. Other areas of interest were prefrontal cortex (PFC), the posterior parietal cortex, and the medial temporal lobe.
If subjects failed to solve the riddle, and then were shown the correct
answer, they displayed the feeling of insight, which reflected the electroencephalogram recordings.
Overall, it is quite apparent that there are many aspects that
can explain the Aha! effect. No particular area has been determined but
from the information gathered, it seems that insight occurs in many
parts of the brain, within a given time period.
Evidence in fMRI studies
A study with the goal of recording the activity that occurs in the brain during an Aha! moment using fMRIs
was conducted in 2003 by Jing Luo and Kazuhisa Niki. Participants in
this study were presented with a series of Japanese riddles, and asked
to rate their impressions toward each question using the following
scale: (1) I can understand this question very well and know the answer;
(2) I can understand this question very well and feel it is
interesting, but I do not know the answer; or (3) I cannot understand
this question and do not know the answer.
This scale allowed the researchers to only look at participants who
would experience an Aha! moment upon viewing the answer to the riddle.
In previous studies on insight, researchers have found that participants
reported feelings of insight when they viewed the answer to an unsolved
riddle or problem.
Luo and Niki had the goal of recording these feelings of insight in their participants using fMRIs.
This method allowed the researchers to directly observe the activity
that was occurring in the participant's brains during an Aha! moment.
- An example of a Japanese riddle used in the study: The thing that can move heavy logs, but cannot move a small nail → A river.
Participants were given 3 minutes to respond to each riddle, before
the answer to the riddle was revealed. If the participant experienced an
Aha! moment upon viewing the correct answer, any brain activity would
be recorded on the fMRI.
The fMRI results for this study showed that when participants were given the answer to an unsolved riddle, the activity in their right hippocampus increased significantly during these Aha! moments. This increased activity in the right hippocampus may be attributed to the formation of new associations between old nodes. These new associations will in turn strengthen memory for the riddles and their solutions.
Although various studies using EEGs, ERPs, and fMRI's report
activation in a variety of areas in the brain during Aha! moments, this
activity occurs predominantly in the right hemisphere. More details on
the neural basis of insight see a recent review named "New advances in
the neural correlates of insight: A decade in review of the insightful
brain"
Insight problems and problems with insight
Insight problems
The Nine Dot Problem
The
Nine Dot Problem with solution. Most individuals fail to draw lines
beyond the dots that compose the square, and are unable to solve this
puzzle.
The Nine Dot Problem is a classic spatial problem used by
psychologists to study insight.
The problem consists of a 3 × 3 square created by 9 black dots. The task
is to connect all 9 dots using exactly 4 straight lines, without
retracing or removing one's pen from the paper. Kershaw & Ohlsson report that in a laboratory setting with a time limit of 2 or 3 minutes, the expected solution rate is 0%.
The difficulty with the Nine Dot Problem is that it requires
respondents to look beyond the conventional figure-ground relationships
that create subtle, illusory spatial constraints and (literally) "think outside of the box".
Breaking the spatial constraints shows a shift in attention in working
memory and utilizing new knowledge factors to solve the puzzle.
Verbal riddles
Verbal riddles are becoming popular problems in insight research.
Example: "A man was washing windows on a high-rise building when
he fell from the 40-foot ladder to the concrete path below. Amazingly,
he was unhurt. Why? [Answer] He slipped from the bottom rung!"
Matchstick arithmetic
Matchstick arithmetic, which was developed and used by G. Knoblich,
involves matchsticks that are arranged to show a simple but incorrect
math equation in Roman numerals. The task is to correct the equation by
moving only one matchstick.
Two examples of Matchstick Arithmetic Problems.
Anagrams
Anagrams
involve manipulating the order of a given set of letters in order to
create one or many words. The original set of letters may be a word
itself, or simply a jumble.
Example: Santa can be transformed to spell Satan.
Rebus puzzles
Rebus
puzzles, also called "wordies", involve verbal and visual cues that
force the respondent to restructure and "read between the lines" (almost
literally) to solve the puzzle.
Some examples:
- Puzzle: you just me [Answer: just between you and me]
- Puzzle: PUNISHMENT [Answer: capital punishment]
- Puzzle:
i i i
OOOOO
[Answer: circles under the eyes]
Remote Associates Test (RAT)
The Remote Associates Test (known as the RAT) was developed by Martha Mednick in 1962 to test creativity. However, it has recently been utilized in insight research.
The test consists of presenting participants with a set of words, such as lick, mine, and shaker. The task is to identify the word that connects these three seemingly unrelated ones. In this example, the answer is salt.
The link between words is associative, and does not follow rules of
logic, concept formation or problem solving, and thus requires the
respondent to work outside of these common heuristical constraints.
Performance on the RAT is known to correlate with performance on other standard insight problems.
The Eight Coin Problem
In
this problem a set of 8 coins is arranged on a table in a certain
configuration, and the subject is told to move 2 coins so that all coins
touch exactly three others. The difficulty in this problem comes from
thinking of the problem in a purely 2-dimensional way, when a
3-dimensional approach is the only way to solve the problem.
Problems with insight
Insight research is problematic because of the ambiguity and lack of agreement among psychologists of its definition.
This could largely be explained by the phenomenological nature of
insight, and the difficulty in catalyzing its occurrence, as well as the
ways in which it is experimentally "triggered".
An example where another solution than the evident solution (number 6) must be found.
The pool of insight problems currently employed by psychologists is
small and tepid, and due to its heterogeneity and often high difficulty
level, is not conducive of validity or reliability.
One of the biggest issues surrounding insight problems is that
for most participants, they're simply too difficult. For many problems,
this difficulty revolves around the requisite restructuring or
re-conceptualization of the problem or possible solutions, for example,
drawing lines beyond the square composed of dots in the Nine-Dot
Problem.
Furthermore, there are issues related to the taxonomy of insight
problems. Puzzles and problems that are utilized in experiments to
elicit insight may be classified in two ways. "Pure" insight problems
are those that necessitate the use of insight, whereas "hybrid" insight
problems are those that can be solved by other methods, such as the
trial and error.
As Weisberg (1996) points out, the existence of hybrid problems in
insight research poses a significant threat to any evidence gleaned from
studies that employ them. While the phenomenological experience of
insight can help to differentiate insight-solving from non-insight
solving (by asking the respondent to describe how they solved the
problem, for example), the risk that non-insight solving has been
mistaken for insight solving still exists. Likewise, issues surrounding
the validity of insight evidence is also threatened by the
characteristically small sample sizes. Experimenters may recruit an
initially adequate sample size, but because of the level of difficulty
inherent to insight problems, only a small fraction of any sample will
successfully solve the puzzle or task given to them; placing serious
limits on usable data. In the case of studies using hybrid problems, the
final sample is at even greater risk of being very small by way of
having to exclude whatever percentage of respondents solved their given
puzzle without utilizing insight.
The Aha! effect and scientific discovery
There
are several examples of scientific discoveries being made after a
sudden flash of insight. One of the key insights in developing his special theory of relativity came to Albert Einstein while talking to his friend Michele Besso:
I started the conversation with him in the following way: "Recently I have been working on a difficult problem. Today I come here to battle against that problem with you." We discussed every aspect of this problem. Then suddenly I understood where the key to this problem lay. Next day I came back to him again and said to him, without even saying hello, "Thank you. I've completely solved the problem."
However, Einstein has said that the whole idea of special relativity did not come to him as a sudden, single eureka moment, and that he was "led to it by steps arising from the individual laws derived from experience". Similarly, Carl Friedrich Gauss said after a eureka moment: "I have the result, only I do not yet know how to get to it."
Sir Alec Jeffreys had a eureka moment in his lab in Leicester after looking at the X-ray film image of a DNA
experiment at 9:05 am on Monday 10 September 1984, which unexpectedly
showed both similarities and differences between the DNA of different
members of his technician's family. Within about half an hour, he realized the scope of DNA profiling, which uses variations in the genetic code to identify individuals. The method has become important in forensic science to assist detective work, and in resolving paternity and immigration disputes. It can also be applied to non-human species, such as in wildlife population genetics
studies. Before his methods were commercialized in 1987, Jeffreys'
laboratory was the only center carrying out DNA fingerprinting in the
world.
