The eureka effect (also known as the Aha! Moment or eureka moment ) refers to the common human experience of a previously unknown incomprehensible problem or concept. Some research describes the Aha! effect (also known as insight or epiphany ) as a memory advantage,  but conflicting results, which is quite likely to occur in the brain, and it is difficult to predict an Aha! moment.
Insight is a psychological term that attempts to describe the process Often this transition is accompanied by an exclamation of joy or satisfaction, an Aha! moment. A person who uses insight to solve a problem is able to give an accurate, discrete, all-or-nothing type of response. 
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 positive elicits 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! The problem is one of failing, where they are likely to be able to survive, but they are unlikely to be able to solve the problem. The second phase suddenly and unexpectedly. After a break in mental fixation or re-evaluating the problem, the answer is retrieved.  Some research suggests that problems are difficult to solve.  In order to solve problems, one must think outside the boxIt is this elaborate rehearsal that it is possible to have a break in mental fixation, allowing the solution to appear transparent and obvious.
History and etymology
The effect is named after 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. 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. Uncategorized, the concept of an irregular object, and the conception of a method of solving the problem, Archimedes allegedly leaped out and ran home naked, shouting “eureka” (I have found it). This story is now fictional, because it was first mentioned by the Roman writer Vitruviusnearly 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 .
The Eureka effect was first described by Pamela Auble, Jeffrey Franks and Salvatore Soraci in 1979. The subject would be presented with an initial 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 understand the sentence, and this resulted in better memory on memory tests. Subjects spend a considerable amount of time attempting to solve the problem, and it is hypothesized that understanding towards understanding. 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 been significantly improved. In fact, they have been obtained for easy and hard sentences which are initially incomprehensible. It seems to be this noncomprehension to understand which results in better recall. The essence of the aha feeling underling insight problem solving was systemically empirically investigated by Shen and his colleagues. 
How people solve insight problems
Currently there are two theories for how to 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. They can not solve the problem while on their path, they will seek alternative solutions. In insight problems this usually happens 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 the success of the problem. Once the person relaxes his or her constraints, they can make a mistake. They also use chunk decomposition, where they will separate their 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, to which point they may exclaim, “Aha!” Currently, 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 is an initial confusion.  When subjects were presented with a 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.
It had been determined that the subject was greater than that of the subject when it was generated by the subject.  There seems to be a memory where they are able to produce an answer themselves, recall was higher when Aha! reactions occurred.  They have been tested to a greater or lesser extent, but when presented with a word, the understanding becomes more apparent. Other evidence was presented that stimuli was more often used than the stimuli that were presented. This study was done using the golden dots or verbal instruction to produce a real gold image. It is believed that effort is made to understand something when encoding and activation of the alternative. 
Functional magnetic resonance imaging and electroencephalogram studies  -have found Requiring insight problem solving That Involves Increased activity in the right cerebral hemisphere as Compared with problem solving not Requiring insight. In particular, increased activity in the right hemisphere anterior superior temporal gyrus .
Some unconscious processing can take place while you are in your dreams, 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 he was eating his own tail .  Studies have shown increased performance in the field of problem solving. Sleep can function to restructure problems, and allow new insights to be achieved.  Henri Poincaré stated that he is thinking of a time for “unconscious thought” that helped him break through problems. [ citation needed]
Professor Stellan Ohlsson believes that the beginning of the problem-solving process, some salient features of the problem is 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 changes the mental representation of a problem, and causes 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 asks the question to answer 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, do they ounce They are required to press a key. After which the answer appears on the screen. If they were unsure or did not know the answer, then they would not answer the question.
Evidence in EEG studies
Resting-state neural activity has a positive influence on cognitive strategies used when solving problems, particularly in the case of solutions by methodical search or by sudden insight.  The two cognitive strategies used in both problem and problem solving, while the problem is noticeable. 
Subjects studied were first recorded on the base-line resting state of thinking. After being white tested using the method Described in the General Procedure for Conducting ERP and EEG Studies , the ratio of insight versus non-insight solutions Were made to determine whether an individual is classified as a high Insight (HI) gold low Insight (LI) individual. Discriminating between HI and Cognitive strategies were used to solve problems in this study.  Right hemisphere activation is believed to be involved in Aha! effects, so it comes as no surprise that it 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 the dorsal-frontal (low-alpha band), right inferior-frontal (beta and gamma band) 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 is suggested that individuals who are highly creative exhibit diffuse attention, thus allowing them a greater range of environmental stimuli.  It would have been less than occipital state alpha-band activity, meaning there would be less inhibition of the visual system.  Individuals who were less creative were found to focus their attention, thus causing them to sample less of their environment.  Although, 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 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 more “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 that year Aha! effect was elicited at N320 which has a strong activation in the central-posterior region.  These previous studies reflect the premise of the study, that the Aha! OCCURS effect in the anterior cingulate cortex , while this study finds results indicating indication the posterior cingulate cortexis responsible. It has been found in the post- mortem cortexfor successful guessing of logographs, not in the anterior cingulate cortex . The posterior cingulate cortex seems to play a more important role in cognitive function. 
Another significant finding of this study 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 a search for 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, they 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 specific area has been determined, but 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 towards each question using the following scale: (1) I can understand this question very well and know the answer; (2) I can understand this question and feel it is interesting, but I do not know the answer; or (3) I can not understand this question and do not know the answer. This scale allowed the researchers to attend participants who would experience an Aha! moment when viewing the answer to the riddle. In previous studies on insight, researchers found that participants reported feelings of insight when they read the answer to an unsolved problem.  Luo and Niki had the goal of recording these feelings of insight in their participants using fMRIs . This method allowed the researchers to be directly involved 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 can not 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! the moment when 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 a problem, the activity in their right hippocampus increased significantly during these aha! times. This activity in the right hippocampus can be attributed to the formation of new associations between old nodes.  These new associations will be in turn for their memory and their solutions.
Although various studies using EEGs, ERPs, and fMRI’s report in a variety of areas in the brain during Aha! moments, it is interesting to note that this activity occurs predominantly in the right hemisphere. More details on the neural basis of insight 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
The Nine Dot Problem
The Nine Dot Problem is a classic space problem used by psychologists to study insight. The problem consists of 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 a certain amount of thinking about the notion of ” outside the box “. Breaking the spatial constraints shows a shift in attention to working memory and using new knowledge factors to solve the puzzle.
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, which was developed and used by G. Knoblich,  involves matchsticks that are arranged to show a simple but incorrect mathematical equation in Roman numerals. The task is to correct the equation by moving only one matchstick.
Anagrams involve manipulating the order of a set of letters. The original set of letters may be a word itself, or simply a jumble.
Example: Santa can be transformed to spell Satan .
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.
- Puzzle: you just me [ Answer: just between you and me ]
- Puzzle: PUNISHMENT [ Answer: capital punishment ]
[ 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 been used in insight research.
The test consists of presenting 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 out 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 corners is arranged in a certain configuration, and the subject is told to move 2 corners so that all corners touch exactly 3 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 case is largely 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”.
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 can be used in many ways. “Pure” insight problems are those that require the use of insight, whereas “hybrid” insights are the only ones that can be solved by other methods, such as the trial and error. As Weberg (1996) points out, the existence of hybrid problems in insight research poses a significant threat to any evidence of employment. Uncategorized the concept of insight-solving (non-insight-solving), the risk of non-insight-solving . Likewise, issues surrounding the validity of insight is also threatened by the characteristically small sample sizes. Experimenters may only be successful in the first instance, but only because of the level of difficulty; serious limits on usable data.
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: “I’ve been working on a problem today.” We discussed every aspect of this problem. Then suddenly I understand where the key to this problem lay. Next day I came back to him again, 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 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 watching the movie X-ray image of a DNA experiment at 9:05 am on Monday, September 10, 1984, which unexpectedly showed both similarities and differences between the DNA of different members his technician’s family.   Within 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 with detective work, and in resolving paternity and immigration disputes.  It can also be applied to non-human species, such as in wildlifepopulation genetics studies. Before his methods were commercialized in 1987, Jeffreys’ laboratory was the only center carrying DNA fingerprinting in the world. [ quote needed ]
In popular psychology
Popular culture has its own views of the Aha! effect. Although both are defined as the moment of insight that changes one’s state of mind, its applications greatly differ. Where scientists have focused on understanding the mechanisms of insights and where Aha! moments occur in the brain, Oprah Winfrey has taken this phenomenon and turned it into a popular and well-recognized state of mind. By Oprah views the Aha! effect a sudden moment of realization, where an individual recognizes that they need to make a change or move forward in life. Oprah includes Aha! Moments in her monthly magazine, O: The Oprah Magazine, and commonly made references to these moments of television, Oprah . 
- Rubber duck debugging
- ^ Jump up to:a b c d Auble, P .; Franks, J .; Soraci, S. (1979). “Effort towards comprehension: Elaboration or aha !?”. Memory & Cognition . 7 : 426-434. doi : 10.3758 / bf03198259 .
- ^ Jump up to:a b c d e f g Kounios, Fleck; Green, Payne; Stevenson, Bowden; Jung-Beeman (2008). “The Origins of Insight in Resting-State Brain Activity”. Neuropsychologia . 46 : 281-291. doi : 10.1016 / j.neuropsychologia.2007.07.013 .
- Jump up^ Topolinski, S .; Reber, R. (2010). “Gaining insight into the” Aha “-experience”. Current Directions in Psychological Science . 19 : 402-405. doi :10.1177 / 0963721410388803 .
- Jump up^ Wray, H. (2011). “Aha! The 23-Across Phenomenon”. APS Observer . 24 : 1.
- ^ Jump up to:a b Qui & Zhang (2008) “Aha! Effects in a Chinese Guessing Logograph Task: An Event-Related Potential Study.” Chinese Science Bulletin, 53 (3), 384-391.
- ^ Jump up to:a May B , Luo; Wu; Lo, Y. (2004). ” ” Aha! “Effects in a Guessing Riddle Task: An Event-Related Potential Study”. Human Brain Mapping . 22 : 261-270. doi : 10.1002 / hbm.20030 .
- Jump up^ Fact or Fiction ?: Archimedes Coined the Term “Eureka!” in the Bath, Scientific American
- Jump up^ Shen, W .; Yuan, Y .; Liu, C .; Luo, J. (2015). “In search of the ‘Aha!’ experiment: Elucidating the emotionality of insight problem-solving “. British Journal of Psychology . 107 : 281-298. doi : 10.1111 / bjop.12142 .
- Jump up^ MacGregor, J .; Ormerod, T .; Chronicle, E. (2001). “Information processing and insight: A process model of performance on the nine-dot and related problems”. Journal of Experimental Psychology: Learning, Memory, and Cognition . 27 : 176-201. doi : 10.1037 / 0278-73184.108.40.206 .
- Jump up^ Knoblich, G .; Ohlsson, S .; Raney, GE (2001). “An eye movement study of insight problem solving”. Memory & Cognition . 29 : 1000-1009. doi : 10.3758 / bf03195762 .
- Jump up^ Jones, G (2003). “Testing two cognitive theories of insight”. Journal of Experimental Psychology: Learning, Memory, and Cognition . 29 (5): 1017-1027. doi : 10.1037 / 0278-73220.127.116.117 .
- Jump up^ Wills, TW; et al. (2006). “The Aha Effect in Groups and Other Dynamic Learning Contexts”. The Journal of General Psychology . 133 (3): 221-236. doi : 10.3200 / genp.133.3.221-236 .
- Jump up^ Peynircioglu, F (1989). “The generation effect with pictures and nonsense figures”. Acta Psychologica . 70 : 153-160. doi : 10.1016 / 0001-6918 (89) 90018-8 .
- Jump up^ Wills, T .; Soraci, S .; Chechile, R .; Taylor, H. (2000). ” ” Aha “effects in the generation of pictures”. Memory & Cognition . 28 : 939-948. doi : 10.3758 / bf03209341 .
- Jump up^ Jung-Beeman, Mark; Bowden, Edward M .; Haberman, Jason; Frymiare, Jennifer L .; Arambel-Li, Stella; Greenblatt, Richard; Rebe, Paul J .; Kounios, John (2004), “Neural Activity When People Solve Verbal Problems with Insight” , PLoS Biology , 2 (4), p. e97, PMC 387268 , PMID 15094802 , doi : 10.1371 / journal.pbio.0020097
- ^ Jump up to:a b Scientific American Mind , October / November 2006
- Jump up^ Wagner, U. et al. (2004)Sleep Inspires Insight, Nature 427, pp. 352-355.
- Jump up^ Bowden, EM; Jung-Beeman, M .; Fleck, J .; Kounios, J. (2005). “New approaches to demystifying insight”. Trends in Cognitive Sciences . 9 : 322-328. doi : 10.1016 / j.tics.2005.05.012 .
- ^ Jump up to:a b Friedman, RS; Forster, J. (2005). “Effects of motivational cues on perceptual asymmetry: implications for creativity and analytical problem solving”. Journal of Personality and Social Psychology . 88 : 263-275. doi : 10.1037 / 0022-3518.104.22.1683 .
- Jump up^ Zhang, Q .; Qiu, J .; Cao, G. (2004). “A review and hypothesis about the cognitive mechanism of insight”. Psychology Science . 27 : 1435-1437.
- ^ Jump up to:a b c d e Luo Jing; Niki, Kazuhisa (2003). “Function of Hippocampus in” Insight “of Problem Solving”. Hippocampus . 13 : 316-323. doi : 10.1002 / hipo.10069 .
- Jump up^ Shen, WangBing; Luo, Jing; Liu, Chang; Yuan, Yuan (2013). “New advances in the neural correlates of insight: A decade in review of the insightful brain.” Chinese Science Bulletin . 58 (13): 1497-1511. doi : 10.1007 / s11434-012-5565-5 .
- Jump up^ Kershaw, T .; Ohlsson, S. (2004). “Multiple Causes of Difficulty in Insight: The Case of Nine-Dot Problem”. Journal of Experimental Psychology: Learning, Memory, and Cognition . 30 : 3-13. doi : 10.1037 / 0278-7322.214.171.124 .
- Jump up^ Knoblich, G .; Ohlsson, S .; Haider, H .; Rhenius, D. (1999). “Constraint, Relaxation and Chunk Decomposition in Solving Problem Solving”. Journal of Experimental Psychology: Learning, Memory and Cognition . 25 : 1534-1555. doi : 10.1037 / 0278-73126.96.36.1994 .
- Jump up^ Mednick, M (1963). “Research Creativity in Psychology Graduate Students”. Journal of Consulting Psychology . 27 : 265-266. doi : 10.1037 / h0042429 .
- Jump up^ Ollinger, M .; Jones, G .; Knoblich, G. (2008). “Investigating the Effect of Mental Set on Insight Problem Solving”. Experimental Psychology . 55 : 269-282. doi : 10.1027 / 1618-3188.8.131.529 .
- Jump up^ Ormerod, T .; Chronicle, E .; Macgregor, J. (2002). “Dynamics and Constraints in Solving Problem Solving”. Journal of Experimental Psychology: Learning, Memory and Cognition . 23 : 791-799.
- Jump up^ MacGregor, J .; Cunningham, B. (2008). “Rebus puzzles as insight problems”. Behavior Research Methods . 40 : 263-268. doi : 10.3758 / brm.40.1.263 .
- Jump up^ Chronicle, E .; MacGregor, J .; Ormerod, T. (2004). “What Makes an Insight Problem? The Roles of Heuristics, Goal Design, and Recoding Solution in Knowledge Learning-Problems”. Journal of Experimental Psychology: Learning, Memory and Cognition . 30 : 14-27. doi : 10.1037 / 0278-73184.108.40.206 .
- Jump up^ Einstein, Albert (August 1982), “How I created the theory of relativity”(PDF) , Physics Today , pp. 45-47 , retrieved 2013-05-15
- ^ Jump up to:a b c Moszkowski, Alexander (1972). Conversations with Einstein . London: Sidgwick & Jackson. pp. 96-97. ISBN 0-283-97924-0 .
- Jump up^ Dunnington, Guy Waldo; Gray, Jeremy; Dohse, Fritz-Egbert (2004). Carl Friedrich Gauss: Titan of Science . The Mathematical Association of America. p. 418. ISBN 0-88385-547-X .
- ^ Jump up to:a b “Desert Island Discs with Alec Jeffreys’ . Desert Island Discs . 2007-12-09. BBC . Radio 4 .
- Jump up^ Newton, Giles (2004-02-04). “Discovering DNA fingerprinting: Sir Alec Jeffreys describes its development” . Wellcome Trust . Archived from the original on 15 November 2010 . Retrieved 23 December 2007 .
- Jump up^ http://www.oprah.com/packages/aha-moments.html