Integrated theories of brain function contend that damage to a specific brain area leads to loss of all higher skills dependent on that area.

• A. Higher cognitive abilities are distributed and cannot be lost by damaging a single area.
• B. Brain functions are entirely subcortical.
• C. Only motor skills are affected by focal lesions.
• D. Damaging a specific brain area causes the loss of all higher skills dependent on that area.

Answer: (D)

Integrated theories say that specific brain regions contribute in specialized ways to higher-level skills, so when a particular area is damaged, the higher abilities that depend on that area tend to be impaired. This reflects a close link between structure and function: a lesion can disrupt the domain that region supports, leading to deficits across the dependent skills. The brain, however, works in networks, so the exact pattern of impairment can vary and some related abilities may be partially spared or helped by compensatory pathways.

For example, damage to language-related areas often produces clear difficulties in speech production and comprehension, because those high-level language skills rely on those particular regions. The key idea is that the loss is tied to the functions those areas specifically support, rather than implying that every higher skill tied to that region would indiscriminately disappear.

This view differs from the notion that all higher cognitive abilities are so distributed that a single lesion cannot erase them, and it also rejects the idea that brain function is entirely subcortical or that only motor skills are affected by focal damage.