One way of viewing cognitive changes in abstinent alcoholics is to emphasize alcohol-related changes in brain structure that may cause the impairments. The brain encompasses a layer of tissue that lies just underneath the skull. This layer, called the cerebral cortex, is thought to “house” many cognitive functions (for locations and definitions of this and other brain areas, see the figure, pp. 136–137). According to one view (Lishman 1990), shrinkage of the cerebral cortex, as well as possible atrophy of basal forebrain regions, is thought to be caused by alcohol’s direct neurotoxic effects. Furthermore, thiamine deficiency may result in damage to a region deep within the brain called the diencephalon (perhaps because blood vessels break in that region when the body’s thiamine levels are deficient).
