William W. Beatty

Neuropsychological performance of recently abstinent alcoholics and cocaine abusers

To examine possible influences of premorbid and comorbid factors on the neuropsychological test performance of recently abstinent (3-5 weeks) drug abusers, we studied 24 alcoholics, 23 cocaine abusers, and 22 healthy controls of comparable age and education. Both alcoholics and cocaine abusers performed significantly more poorly than controls on most measures of learning and memory, problem solving and abstraction and perceptual-motor speed, but the groups did not differ on the measure of sustained attention. Correlational analyses revealed no significant relationships between measures of childhood and residual hyperactivity and neuropsychological performance; scores on the Beck Depression Inventory were related only to performance on the Wisconsin Card Sorting Test. The findings indicate that abuse of cocaine or alcohol is associated with deficits on neuropsychological tests which cannot be attributed to specific premorbid or comorbid factors such as depression or childhood or residual attention deficit disorder.

Cortical and subcortical influences on clustering and switching in the performance of verbal fluency tasks

Impairments on lexical and semantic fluency tasks occur in both cortical and subcortical dementia. Recent reports that the average size of phonemic and semantic clusters is reduced in Alzheimers disease (AD), but not in Parkinsons disease (PD) could support the hypothesis that in AD verbal fluency deficits arise from degraded memory storage while in PD the same impairments result from defective retrieval. In the present study, patients with AD, PD with dementia, or Huntingtons disease produced fewer words, fewer switching responses and smaller semantic cluster sizes. Patients with multiple sclerosis, regardless of whether or not they were demented, produced fewer words and switching responses, but normal size clusters, and patients with PD without dementia performed normally on all fluency measures. These results indicate that reductions in cluster size on verbal fluency tests are best interpreted as changes in the efficiency of access to lexical and semantic memory stores. The findings are also consistent with the idea that patterns of cognitive impairment may differ among diseases that result in subcortical dementia.

Demographic, Clinical, and Cognitive Characteristics of Multiple Sclerosis Patients Who Continue to Work

To determine the factors that contribute to maintaining employment by MS patients, we compared thirty-eight patients who were still working to sixty-four patients who retired prematurely. The employed group was younger, better educated, had less severe physical disability, a shorter duration of disease, an earlier age at diagnosis, and per formed significantly better on nearly all neuropsychological variables examined. Mul tiple regression analysis indicated that walking ability, age, two measures of memory, and one test of verbal fluency, taken together, accounted for 49% of the variance in employment status. Although most patients who maintained employment had only mild to moderate physical and cognitive impairments, nine patients who continued to work were impaired on three or more of the seven cognitive domains tested. Implications for more effective rehabilitation are considered.

Verbal fluency deficits in multiple sclerosis

A quantitative review of 35 studies with 3673 participants was conducted to estimate and compare the magnitude of deficits upon tests of phonemic and semantic fluency for participants with multiple sclerosis (MS) relative to healthy controls. Participants with MS were substantially but similarly impaired on tests of phonemic and semantic fluency. These deficits were larger than deficits on measures of verbal intelligence, confrontation naming and another widely used measure of executive functioning, the Wisconsin Card Sorting Test, but were of a comparable or smaller magnitude relative to deficits on the oral version of the Symbol Digit Modalities Test (SDMT). This is consistent with other research suggesting that measures of verbal fluency and the SDMT may be amongst the most sensitive neuropsychological measures to cognitive impairment in MS. Increased neurological disability and a chronic progressive (as opposed to a relapsing remitting) disease course were associated with larger deficits on tests of phonemic and semantic fluency. However, it is suggested that this latter finding is attributable to the distinct clinical features of chronic progressive and relapsing remitting sub-types. Thus, patients who follow a chronic progressive course tend to be older, have an increased duration of illness and experience greater neurological disability. Once these variables were controlled for, differences between the two sub-types were substantially attenuated.

Gonadal Hormones and Sex Differences in Nonreproductive Behaviors

Experimental investigations of the influence of gonadal hormones on sex differences in nonreproductive behaviors have been guided by concepts and methods applied to the study of sexual behavior. In 1959, Phoenix, Goy, Gerall, and Young reported that administration of testosterone propionate to pregnant guinea pigs caused the female offspring to display high levels of male mounting behavior but very low levels of female receptive behavior when tested as adults. This original observation has been confirmed and extended in literally hundreds of published reports. In general the findings indicated that mammals are biased to develop feminine patterns of reproductive function and will only display male-like characteristics if exposed to testicular hormones early in life. The important concept that emerged from this work is that gonadal hormones exert two distinct actions, which are termed organizational and activational effects.

Problem solving by patients with multiple sclerosis Comparison of performance on the Wisconsin and California Card Sorting Tests

Problem solving by patients with clinically definite multiple sclerosis (MS) was examined using the Wisconsin and California Card Sorting Tests (WCST and CCST). On the WCST, the MS patients achieved fewer categories and made more perseverative responses and errors than controls, confirming results of several previous studies. On the CCST, the MS patients generated and identified fewer concepts, but they performed normally when sorting was cued by the experimenter and they made no more perseverations than controls. Although findings from the WCST indicate that the problem solving deficits by MS patients closely resemble those exhibited by patients with various conditions that produce frontal lobe dysfunction, results from the CCST indicate that the problem solving difficulties exhibited by patients with MS are distinct and probably represent a primary deficit in concept formation.

Evidence for deficits in facial affect recognition and theory of mind in multiple sclerosis

Multiple sclerosis (MS) is a white matter disease associated with neurocognitive difficulties. More recently the potential for white matter pathology to also disrupt important aspects of emotion understanding has been recognized. However, no study to date has assessed whether capacity for facial affect recognition and theory of mind (ToM) is disrupted in MS, or whether any observed deficits are related to more general cognitive impairment. In the present study MS participants (n = 27) and nonclinical controls (n = 30) were administered measures of facial affect recognition, ToM, and cognitive functioning. MS participants were significantly impaired on the ToM task, and also presented with specific deficits decoding facial emotions of anger and fear. Performance on the measures of facial affect recognition and ToM were related to general cognitive functioning, and in particular, measures sensitive to executive dysfunction and information processing speed. These data highlight the need for future research to more fully delineate the extent and implications of emotion understanding difficulties in this population.

Psychological and neuropsychological predictors of coping patterns by patients with multiple sclerosis

To determine the relative contribution of psychological and neuropsychological (NP) variables to the prediction of patterns of coping with disease-related stressors and satisfaction with their coping efforts, 56 patients with multiple sclerosis (MS) were administered the Ways of Coping Checklist, the Symptom Checklist-90-Revised, and a battery of NP tests chosen for their sensitivity to MS. Higher levels of psychological distress were associated with greater use of emotion-focused coping strategies and reduced perceived effectiveness of the coping strategies employed. Psychological distress was not related to the use of problem-focused strategies and NP variables did not predict coping style or effectiveness. MS patients who display heightened psychological distress may be good candidates for psychotherapeutic interventions aimed at improving perceived coping effectiveness.

Memory and “frontal lobe” dysfunction in multiple sclerosis

The characteristics of memory disturbance in multiple sclerosis (MS) are briefly reviewed and the interactions of conceptual and memory dysfunction in MS are considered. Although conceptual functions such as abstraction and problem solving traditionally have been considered to be frontal lobe functions, there is now convincing evidence from studies of patients with focal brain lesions that these capacities are not localized to the frontal lobes. Thus, the concept of frontal lobe dysfunction in MS is without empirical support. Nevertheless, studies examining the relationship between memory and conceptual impairment in MS have value for both basic and clinical neuroscience.

Declines in switching underlie verbal fluency changes after unilateral pallidal surgery in Parkinson’s disease

Declines in verbal fluency are consistently reported in patients with Parkinsons disease (PD) after pallidal surgery. In the present study, the clustering and switching components of semantic or category fluency (oral naming of items obtainable in supermarkets) were examined at baseline and four months after unilateral deep brain stimulation or pallidotomy in 45 patients with PD (30 left, 15 right pallidal surgery). Post-operative declines were observed for supermarket fluency total score and switching, but not for average cluster size. These findings support the proposal that semantic fluency decrements after pallidal surgery reflect a disruption of frontal-basal ganglia circuits mediating efficient shifting between semantic categories, or perhaps efficient access to categories, rather than a degradation of semantic stores.