Journal of the International Neuropsychological Society : JINS
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J Int Neuropsychol Soc · Jan 2000
Comparative StudyExploring the relationship between age, executive abilities, and psychomotor speed.
Age-related declines in executive abilities have been widely reported and are thought to result from neuropathological changes in the prefrontal cortex. Some investigators have suggested that age-related changes in cognition may be the result of slowed information processing speed rather than declines in specific cognitive abilities. We examined the relationships among age, executive abilities, and psychomotor speed in 40 older adults and 46 young adults. ⋯ Our results revealed that poorer executive performance was associated with increasing age. Further, although psychomotor speed attenuated the relationship, age accounted for a unique and significant proportion of variance in executive performance after controlling for psychomotor speed. These results suggest that age has an effect on prefrontally mediated executive abilities that cannot be explained solely in terms of psychomotor slowing.
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J Int Neuropsychol Soc · Nov 1999
Comparative StudyPolysubstance abuse and traumatic brain injury: quantitative magnetic resonance imaging and neuropsychological outcome in older adolescents and young adults.
Few studies have examined the consequences of alcohol and drug abuse on TBI though they commonly co-occur. Both TBI and substance abuse independently result in neuropathological changes in the brain such as ventricular enlargement and cortical atrophy, thus it is reasonable to hypothesize that the combination of the two would result in more significant cerebral damage. In this study, 3 groups of patients--traumatically brain injured (TBI) with substance abuse (N = 19), TBI without substance abuse (N = 19), and substance abuse with no TBI (N = 16)--were compared with normal controls (N = 20) on several quantitative MRI (QMRI) measures. ⋯ When controlling for head injury severity, the effects of substance abuse in combination with TBI resulted in greater atrophic changes than seen in any other group. TBI and substance abuse patients' neuropsychological test performances also were examined, and no differences were found among patient groups on any measures. These findings have implications for the deleterious interaction of substance abuse combining with TBI to result in greater neuropathological changes that can be detected by QMRI techniques.
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J Int Neuropsychol Soc · Jul 1998
Verbal learning and memory in alcohol abusers and polysubstance abusers with concurrent alcohol abuse.
To define the combined effects of drug and alcohol abuse on verbal learning and memory, 70 alcoholic and 80 polysubstance abuse (PSA) individuals with concurrent alcohol abuse were compared on a list learning task, the California Verbal Learning Test (CVLT). Despite demonstrating similar learning strategies, response styles, and error patterns, the PSA group nontheless exhibited significantly greater recall deficits than the alcoholic group on the CVLT. ⋯ This pattern of greater deficits on recall than on recognition memory, as well as poor consolidation, is consistent with the initiation-retrieval difficulties of patient groups with subcortical dysfunction. It is concluded that the combined use of alcohol and drugs, cocaine in particular, may compound memory difficulties beyond what is typically observed in alcoholic individuals.