Brain Dysfunction in Social Drinkers

The Effects of Brain Damage on the Performance of Hand Movement Sequences

The frontal lobes, if damaged, may lead to a host of divergent abnormalities, depending on the extent, site, depth, and laterality of the damage. Because of the extensive connections which exist between the frontal lobes and the other systems of the brain, damage to a more remote system may cause frontal system disorder through disconnection. The Hand Movement Test (HMT, Kaufman & Kaufman, 1983) is thought to be sensitive to damage affecting these systems, although the test was developed for use with children rather than adults. This paper examines the effects of three diverse neuropsychological disorders, where damage to the frontal lobes or to their interconnections has been implicated, on hand movement sequencing performance in adults. The three groups studied included patients diagnosed with alcohol-related brain damage (n = 57), patients diagnosed with mild traumatic brain injury (n = 21), and patients diagnosed with age-related dementia (n = 30). HMT performance was significantly poorer in all three clinical groups relative to controls, supporting the addition of this brief, paediatric test in neuropsychological evaluations assessing these disorders.

Effect of social drinking on neuropsychological performance

The effects of social drinking on neuropsychological function have been assessed in a group of healthy male volunteers. Subjects were divided into three groups according to their daily alcohol consumption: (1) 40 g or less (n = 93), (2) 41-80 g (n = 22), (3) 81-130 g (n = 16). Group 1 had been drinking at the present level for a mean of 12.6 years, group 2 for 16.9 years and group 3 for 15.1 years; the differences are not significant. There are no significant differences on any neuropsychological tests variables between groups 1 and 2. However, subjects in group 3 were found to perform at a significantly lower level than groups 1 and 2 on the Rey Auditory Verbal Learning Test, the Austin Maze, and the Little Man and Spatial Memory Tests of the Bexley Maudsley Automated Psychological Screening Test. The pattern of deficits found in heavy social drinkers is less severe but otherwise similar to that found in alcoholics.