The cognitive and neural mechanism of chunk decomposition: A particular form of insight

Abstract

Chunk decomposition refers to decompose familiar patterns into their component elements so that they can be regrouped in a meaningful manner. It is a creative process that can lead to insight. According to the Representation Change Theory, chunk decomposition can help problem solvers to update their interpretation of the problem situation and then restructure the starting states of the problem′s representation. The concept chunk decomposition was put forward by theoretical psychologist Ohlsson S. in 1980s. Since then, studies about the cognitive and neural mechanisms of chunk decomposition have been going on for more than thirty years. Up to now, it has been largely explored. The main findings are as follows: Firstly, chunk decomposition has typical insight attribute, such as ″suddenly″ and ″directly″ finding right solution. Secondly, it is a particular form of insight that occurs at the perceptual level. The early visual cortex shows a tendency of negative activation, whereas the higher visual cortex shows a tendency of positive activation. It suggests that, in order to successfully decompose a chunk, the higher visual areas must at least partly be ′disconnected′ from the input provided by early visual processing. This allows simple features to be rearranged into a different perceptual chunk. Meanwhile, chunk decomposition activates both the dorsal visual pathway and the ventral visual pathway, suggesting that subjects need to perceive both where the chunks are and what the chunks are. Thirdly, there are multiple causes of difficulty to block chunk decomposition, which may exert a ″1+1>2″ enlarged effect. For example, the factors of chunk tightness and familiarity increase the effective connectivity not only between the ″what″ and the ″where″ pathways, but also the functional connection from LITG to LSPL, i.e., from the terminal of the ″what″ pathway to the terminal of the ″where″ pathway. Fourthly, chunk decomposition is a product produced by the co-operation of brain′s left and right cerebral hemisphere. The right hemispheric lateralization advantage is limited to the stage after the failure in insight problem solving. The Zeigarnik effect shows that, the right hemisphere might be more positive in preserve the unsolved problem in mind and also more responsive to the external hint for problem solving. Fifthly, chunk decomposition is the synthesis of consciousness and unconsciousness processing. Probably, the novel processing of insight problem solving is unconscious, while the appropriate processing is conscious; or maybe the incubation stage in Wallace′s four-stage model of problem solving is unconscious, whereas both the illumination and verification stages are conscious.