Aha-oplevelsen i hjernen

I det foregående indlæg prøvede jeg at koble forskellige tilgange til Aha-oplevelsen sammen: En psykologisk, en dramaturgisk og en kognitiv-lingvistisk.
   Når man kan finde korrespondancer og analogier mellem sproglige udtryk i form af fortællinger på den ene side, og kreativitetspsykologiske processer på den anden side, så er det nærliggende at spørge om der ikke også skulle findes hjerneforskning om Aha-oplevelsen.

Og det gør der - nemlig i forhold til den version af Aha-oplevelse som i den kreative proces beskrives som "illumination" - den pludselige indsigt i hvordan et problem skal løses på en ny måde. Indsigt, ikke baseret på linær, logisk og bevidst skridt-for-skridt tænkning og problemløsning, men baseret på det "uforklarlige": intuition. 
   I Anders And-tegneseriern var det visuelle udtryk for den oplevelse: en glødepærer der tændte. Georg Gearløs-figuren havde en sådan "glødepære-makker" i nogle af historierne, husker jeg.
 
Her følger et uddrag af en artikel i NYT, der refererer flere sådanne undersøgelser der har undersøgt hjernens reaktioner når den har en aha-oplevelse:

The “light bulb” or “aha!” experience, in which an answer seems to appear from thin air, relies on a very different method of thinking from standard problem- solving, according to research in the United States.
   Abrupt insights such as Archimedes’ discovery of water displacement, which supposedly prompted the mathematician to jump from his bath shouting “eureka”, produce a characteristic pattern of activity in a specific region of the brain’s right hemisphere, scans have shown. When people work out an answer in deliberative, methodical fashion, however, this eureka centre remains quiet, suggesting that the brain has at least two distinct ways of solving difficult problems.
   Mark Jung-Beeman, of Northwestern University in Chicago, who led the study, said the results suggested that inspiration was qualitatively different from ordinary contemplation and thought.
   “For thousands of years, people have said that insight feels different from more straightforward problem-solving,” he said.
   “We believe this is the first research showing that distinct computational and neural mechanisms lead to these breakthrough moments.
   Edward Bowden, his colleague, said: “As supposedly happened to Archimedes, prior to solving problems with insight people often reach an impasse and are unable to make any progress. They need to reinterpret the problem and integrate information in a new way.
   “Sometimes the mind does this unconsciously, and then the solution suddenly appears in consciousness. To the solver, the solution seems to have come out of thin air, yet is obviously correct.”
   In the study, conducted jointly at Northwestern University and Drexel University in Philadelphia, details of which are published today in the journal Public Library of Science Biology, Dr Jung-Beeman and Dr Bowden asked volunteers to solve a series of word problems. Participants were given a series of three words, such as “fence”, “card” and “master”, and told to think of a single word that would go with each to form a compound word. The answer in this example is “post” — “fencepost”, “postcard”, “postmaster”.
The problems were designed so that most people would solve them methodically and by insight about half of the time each. The volunteers’ brains were scanned using functional magnetic resonance imaging (fMRI) as they solved the problems. When the subjects reported having an “aha! moment”, a region of the brain known as the anterior superior temporal gyrus, in the right temporal lobe, tended to fire with activity. When they solved the problems through methodical working, that region was inactive.
   The anterior superior temporal gyrus is thought to play a critical part in pulling together distantly related information, and may be activated subconsciously to produce sudden insights when all the pieces fall into place.
   A second experiment, which used an electroencephalogram (EEG), measured brainwave activity as subjects solved the problems.
   About a third of a second before a problem was solved with insight, there was a sudden burst of high-frequency activity. This appears to mark the moment of inspiration.

Altså, det ser ud til at der er et særligt center i højre hjernehalvdel kaldet "the anterior superior temporal gyrus", der aktiveres i forbindelse med indsigtsgivende AHA-oplevelser, og som ikke aktiveres ved almindelig skridt for skridt problemløsning. Man må vel antage at det center aktiveres fordi det er indrettet til, som en slags katalysator, at kunne skabe neurale forbindelser mellem lagrede konceptuelle rum som ellers ligger fjernt fra hinanden og som ikke er fast og automatisk neuralt forbundet.
   Metaforisk sagt, så lyser det "eureka-center" op som en glødepære der tænder, når der er "hul igennem". Søger man undersøgelsens forfattere på nette, så finder man dem på følgende adresse: http://groups.psych.northwestern.edu/mbeeman/PLoS_Supp.htm, hvor de skriver:

This right anterior temporal area helps make connections across distantly related information during comprehension. Although all problem solving relies on a largely shared cortical network, the sudden flash of insight occurs when solvers engage distinct neural and cognitive processes that allow them to see connections that previously eluded them.

Jeg har tidligere noteret den bemærkelsesværdige grafiske analogi mellem den biologiske kønnede befrugtning, og den kreative tankeoperation kaldet blending. Her synes jeg også der er tale om en klar analogi mellem den form for "kortslutning" i hjernens processer, og så den kognitive lingvistiks begreb om blending. Man kan sige at forskerne med "eureka-centret" har fundet det sted i hjernen der muliggør konceptuel blending.