Prodigious calculation performance and neural plasticity

• ¹ Dept. of Neuropsychology/Behavioral Neurobiology, University of Bremen, Germany
• ² Dept. of Neurologie II, Otto-von-Guericke-University , Germany
• ³ Center for Advanced Imaging – Bremen, University of Bremen, Germany

Prodigies are individuals with exceptional mental abilities. We examined CP, a mental calculation prodigy, and a control group of 11 normal calculators for moderate mental arithmetic tasks. CP has also repeatedly been tested for exceptionally difficult exponentiations with a time gap of 20 months. We hypothesized that, if CP would activate similar brain regions as controls for both moderate and very difficult tasks, his special exceptional abilities could rather be explained by neuroplastic changes as a result of obsessive practice than by unusual neuro-cognitive mechanisms. For very difficult exponentiation tasks (first measurement), CP showed activation patterns in brain regions adjacent to those which were activated during moderate task calculation both by CP and control participants. We hypothesize that most importantly neo-cortical networks should be involved in highly over-learned and excessively trained appliance of constantly used algorithms and the recall of number-related chunk knowledge. For mental arithmetic task processing, these networks were discussed to include particularly neo-cortical parietal and frontal brain regions (e.g., Fehr et al., 2007, 2008). For complex exponentiations, CP showed remarkable changes in activation patterns between measurement sessions. These changes inter alia suggest a regional shift of brain activation foci from intra-parietal to adjacent regions, and from the posterior to the anterior part of the middle frontal gyrus (Fig. 1). Left perisylvian activation patterns were observed for the second measurement session only. Inconsistencies of results between sessions were discussed in relation to both potential neural plastic changes due to pronounced involvement of language-related arithmetic processing and strategy-related changes in recall schemes. We concluded that CP´s exceptional calculation performance is based on neuroplastic changes sub-stantially caused by years of daily hours of training com-bined with excellent working memory capabilities. Furthermore, results of the present study imply that the neural substrate, which is necessary to enhance specific skills dramatically by excessive mental training, is highly adaptive and potentially present in every individual.