Searching for the biological basis of human mental abilitites: The relationship between attention and intelligence studied with P3

Abstract

There is consensus that general intelligence is closely related to the efficiency of brain functioning. This idea has roots in Spearman’s theory of intelligence, and is later expanded by Cattell and Horn. Modern psychologists commonly believe that brain activity plays a central role in intelligence, but there is no commonly accepted theory in which this role is accurately described. The main aim of the experiments presented in the thesis was to investigate the relationship between fluid intelligence and the functioning of the neuronal correlates of the attention system. Brain activity was recorded using Event-Related Potentials (ERPs) methodology, in subjects distinguished by their score on psychometric tests of intelligence. Latency and amplitude of the P3 subcomponents of the ERP were used as indices of the early phase of attentional resource allocation The experimental outcomes support the thesis that the frontal and parietal cortical regions constitute the neuronal basis of human fluid intelligence. This is consistent with findings from previous electrophysiological and neuroimaging studies, suggesting that the brain activity within these regions differs significantly between subjects scoring ‘low’ and ‘high’ on tests measuring fluid intelligence. It has also been previously suggested that the same brain parts form the network are involved in attention mechanism. Due to this, it is proposed that the efficiency of the attention functioning can be closely related to fluid intelligence.