Evolution of cognitive function via redeployment of brain areas

0.0475). For average minimum graph distance, language is greater than perception by

1.11 (p = 0.0121) and greater than attention by 1.69 (p = 0.0003). Differences between
other categories are not significant (Table 2).

Table 2: Results for all category comparisons on average number of brain regions activated per task and

average minimum graph distance between the activated regions. Note that only the differences between
language and perception and language and attention are significant.

The last important prediction of the redeployment hypothesis to be discussed here is that
evolutionarily older brain areas should be deployed in more cognitive functions. Figure 2
gives the results of plotting the number of tasks that activate a given Brodmann area
versus the Y-coordinate of the area, based on the simplifying assumption that areas in the
rear of the cerebral cortex (occipital lobe) are evolutionarily older than those in the front
(pre-frontal cortex), ceterus paribus. Although the data are highly variable, as expected,
there is nevertheless a significant linear correlation.

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