Seventy-four patients with focal brain lesions were compared to a neurologically normal control group on tasks of letter-based and category-based list generation. When patients were divided only by right frontal, left frontal, or nonfrontal lesion sites, the pattern of fluency impairments confirmed prior claims. When more precise lesion sites within the frontal lobes were compared between groups classified based on their fluency performance, much more specific brain–behavior relations were uncovered. Damage to the right dorsolateral cortical or connecting striatal regions, the right posterior area, or the medial inferior frontal lobe of either hemisphere did not significantly affect letter-based fluency performance. Superior medial frontal damage, right or left, resulted in moderate impairment. Patients with left dorsolateral and/or striatal lesions were most impaired. Left parietal damage led to performance relatively equivalent to the superior medial and left dorsolateral groups. The same lesion sites produced impairments in category based fluency, but so did lesions of right dorsolateral and inferior medial regions. Task analysis and correlations with other measures revealed that different cognitive processes related to different brain regions underlie performance on verbal fluency tests. (JINS, 1998, 4, 265–278.)

Former neuropsychological studies with Chronic Fatigue Syndrome (CFS) patients evaluated a broad range of cognitive functions. Several, but not all, reported subtle attentional and memory impairments suggesting possible mild cerebral involvement. In this study, a battery of attentional tests and a verbal memory task were administered to 20 CFS patients and 22 healthy controls (HC) in order to clarify the specific nature of attention and memory impairment in these patients. The results provide evidence for attentional dysfunction in patients with CFS as compared to HC. CFS patients performed more poorly on a span test measuring attentional capacity and working memory. Speeded attentional tasks with a more complex element of memory scanning and divided attention seem to be a sensitive measure of reduced attentional capacity in these patients. Focused attention, defined as the ability to attend to a single stimulus while ignoring irrelevant stimuli, appears not to be impaired. CFS patients were poorer on recall of verbal information across learning trials, and poor performance on delayed recall may be due to poor initial learning and not only to a retrieval failure. (JINS, 1998, 4, 456–466.)

The Landau-Kleffner Syndrome (LKS) is characterized by acquired receptive aphasia and EEG abnormality with onset between the ages of 3 and 8 years. This study presents neuropsychological assessments in 5 children with LKS. The aims were (1) to specify the neuropsychological deficits characteristic of these children; and (2) to clarify the nature of the receptive aphasia by comparing nonverbal and verbal auditory discrimination. Receptive aphasia was present in all children. Retardation, poor motor coordination, hyperkinesia, and conduct problems were frequent but variable. All children exhibited a dissociation between the discrimination of environmental sounds and phonological auditory discrimination, the latter being more impaired than the former. This suggests that the primary deficit of the receptive aphasia is an impairment of auditory phonological discrimination rather than a generalized auditory agnosia. (JINS, 1998, 4, 566–575.)

Two components of verbal fluency performance—clustering (i.e., generating words within subcategories) and switching (i.e., shifting between subcategories)—were examined in patients with dementia of the Alzheimer type (DAT), patients with dementia with Parkinson's disease (DPD), nondemented patients with Parkinson's disease (NPD), and demographically matched controls. The DAT and DPD groups were impaired in the number of words generated on both phonemic and semantic fluency. The DAT group produced smaller clusters on both tasks and switched less often on semantic fluency than controls. The DPD group switched less often on both tasks and produced smaller clusters on phonemic fluency than controls. The NPD group was not impaired on any fluency variable. Thus, the total number of words generated on phonemic and semantic fluency did not discriminate the dementia groups from their respective control groups, but measures of clustering and switching did. This differential pattern of performance provides evidence for the potential usefulness of measures of switching and clustering in the assessment of dementia. (JINS, 1998, 4, 137–143.)

The goal of this study was to further characterize episodic memory functioning in schizophrenia. This study compared verbal and visual learning and memory performance in (1) patients with schizophrenia (N = 35), (2) patients with temporal lobe epilepsy (TLE; N = 30), and (3) normal controls (N = 25). Results indicated significant memory impairments in patients with schizophrenia and TLE. “Savings” score measures of memory decay showed that the loss of information in schizophrenia and TLE was approximately equal, and quantitatively mild compared to that found in most neurologic groups with memory disorders. The severe difficulty shown by the schizophrenia group on a task of incidental recall suggested that the absence of instructional set added to a vulnerability to memory deficit. In contrast, relatively mildly impaired performance on paired associate learning suggested that patients with schizophrenia benefited from retrieval cues, multiple trials, and short (nonsupraspan) informational loads. Because patients with schizophrenia consisted of a relatively nonchronic sample with a mean IQ of 99.7, their memory disorder could not be attributed to schizophrenic dementia, nor was it accounted for by other potential confounds. Patients with schizophrenia, even those relatively early in the course of illness, have a mild episodic memory disorder. (JINS, 1998, 4, 342–352.)

No previous comparison of test performance in probable Alzheimer's disease (pAD) and Parkinson's disease (PD) dementia has provided information about potential differences in the dementing process. This study compared the evolution of cognitive changes associated with these dementias. Generalized estimating equations (GEE) applied to regression analyses with repeated measures were used to evaluate cognitive changes over 1 to 3 years prior to the point when dementia was diagnosed in 40 matched pairs of patients with incident pAD and PD dementia. Both groups' performance declined on the Short Blessed, Selective Reminding Test (SRT; total recall, long-term retrieval, and delayed recall), Boston Naming Test, Category Fluency, and Similarities. The decline on naming and SRT delayed recall was more rapid in the PD dementia group, suggesting that these performance deficits emerge earlier in the development of pAD. The PD dementia group performed worse on Category Fluency throughout the follow-up period, suggesting either that dementia is overlaid on this preexisting performance deficit or that this type of executive deficit is an early manifestation of dementia in PD. The pAD group performed more poorly throughout the follow-up period on SRT delayed recognition, consistent with a pAD-specific encoding deficit. We conclude that while pAD and PD dementia are similar in many respects, differences in their evolution support previous observation of unique features in the 2 dementias and suggest different underlying pathologies. (JINS, 1998, 4, 279–284.)

A cluster analytic solution based upon a battery of tests consisting of the Halstead Category and Tactual Performance Tests, the Trail Making Test, and the Wisconsin Card Sorting Test was compared with a solution based on the subtests of the Wechsler intelligence scales, utilizing a sample of 221 schizophrenic patients. Both analyses permitted four-cluster solutions, and we found a weak but significant degree of association between solutions. Examination of external validity of the two solutions revealed stronger associations with clinical variables for the Wechsler-scale-based solution. The major conclusions were that the existence of cognitive heterogeneity in schizophrenia exists across a broad range of abilities, and appears to reflect a combination of continuity of ability level and existence of possible subtypes requiring further neuropsychological and neurobiological verification. (JINS, 1998, 4, 353–362.)

This study investigated the nature of selective attention deficits after severe closed head injury (CHI). Twenty participants with severe CHI (greater than 1 year postinjury) and 20 matched controls completed search and nonsearch visual selective attention tasks under conditions of low (Experiment 1) and high (Experiment 2) target–distractor similarity. In the search situations, participants searched visual displays that contained 1, 4, or 8 items for the targets. In the nonsearch situations, the location of the targets was visually cued with a peripheral arrow. The results revealed that in both the low and high target–distractor similarity search conditions, CHI participants required a longer time than controls to locate and identify the target. In contrast, in the nonsearch condition, CHI participants were able to successfully ignore irrelevant task information when target–distractor similarity was low. However, when target–distractor similarity was high, CHI participants had more difficulty than controls ignoring the irrelevant information. These results suggest that, in comparison to controls, CHI participants may be at a disadvantage in selective attention situations when visual search is required and when the discriminability between targets and distractors is difficult. (JINS, 1998, 4, 144–159.)

Recent studies have detected basal ganglia atrophy in clinically asymptomatic persons with the genetic mutation that causes Huntington's disease (HD). Whether reductions in caudate and putamen volume on MRI scans are associated with changes in cognitive and neurologic functioning was examined in 13 healthy adults with the IT-15 mutation. Reduced striatal volume was found to correlate with greater neurologic (largely motor) impairment, slower mental processing speed, and poorer verbal learning, although none of the participants met even liberal criteria for clinical diagnosis of HD. These correlations are strikingly similar to those observed in symptomatic HD patients, possibly reflecting the earliest manifestations of disease. (JINS, 1998, 4, 467–473.)

It is controversial whether age of disease onset is related to cognitive decline in Parkinson's disease (PD). We administered 7 cognitive measures assessing visuospatial skills, memory, and executive functions to 222 patients with idiopathic PD and 108 normal control participants. Regression analyses demonstrated that older age of disease onset consistently predicted cognitive decline above and beyond normative aging and duration of illness. These findings suggest that older age of disease onset is a critical determinant of cognitive deterioration in PD. (JINS, 1998, 4, 285–290.)

This study examined the effect of varying the number of potential target words on amnesic patients' category exemplar production performance. In Experiment 1, 4 words from each of 6 categories were presented to amnesic patients and normal control participants. This was followed by an indirect task in which each participant produced the first 8 words that came to mind when presented with a category cue. On this task the amnesic patients were impaired. This outcome stands in sharp contrast to most other category exemplar production tasks that have been reported. However, these other paradigms tend to restrict participants' processing during target item presentation while our procedure allowed them to analyze the target words as they chose. Our procedure may have allowed the control participant more opportunity to “cluster” target words from the same category during list presentation and this, in turn, may have given them an advantage at the time of category exemplar production. Therefore, in Experiment 2, only 1 word per category was presented in the target list and only 2 words per category were requested during category exemplar production. Surprisingly, the amnesic patients still exhibited impaired performance. Therefore, it was suggested that perhaps amnesic patients' known inability to perform semantic levels of processing during individual target word presentation may have resulted in impaired priming for categorical features for these patients. (JINS, 1998, 4, 576–583.)

Several tests from the CANTAB neuropsychological test battery previously shown to be sensitive to frontal lobe dysfunction were administered to a large group of normal volunteers (N = 341) ranging in age from 21 to 79 years. The main tests included a computerized form of the Tower of London test of planning, a self-ordered spatial working memory task, and a test of attentional set formation and shifting. A computerized form of the Corsi spatial span task was also given. Age-related graded declines in performance were seen, sometimes in a discontinuous manner, especially for the attentional set shifting task (at the extradimensional shift stage). Patterns of deficits reminiscent of frontal lobe or basal ganglia damage were observed in the oldest age group (74–79). However, overall the data were only partially consistent with the hypothesis that frontal lobe functions are the most sensitive to effects of aging. Factor analyses showed that performance in the executive tests was not simply related to a measure of fluid intelligence, and their performance had a factor loading structure distinct from that for the CANTAB tests of visual memory and learning previously administered to the same sample. Finally, only limited support was found for the hypothesis that cognitive aging depends on slowed information processing. (JINS, 1998, 4, 474–490.)

Two samples of participants from the U.S.–Mexico Borderland (N = 185) versus Spain (N = 205) were compared on 16 Spanish-language neuropsychological measures. In most measures the two samples obtained similar results. There were some significant main effects of place of birth and some significant interactions between education and place of birth. Differences between the samples diminished with increasing levels of education. Within the Borderland sample, percent of life span spent in the U.S. and bilingual status were correlated with performance in some tests. Increased percent of life span spent in the U.S. was negatively correlated with performance on a Spanish word-generation task, and positively correlated with performance on the Wisconsin Card Sorting Test. Bilingual Borderland participants performed significantly better than monolingual speakers in learning a list of words. We suggest that the most likely causes for the observed interaction effects are documented regional differences in early SES-related nutrition, medical care, quality of educational experiences, and general socioeconomic conditions. (JINS, 1998, 4, 363–379.)

The purpose of this study was to examine regional cerebral blood flow using positron emission tomography (PET) during the performance of tasks related to visual confrontation naming. Ten healthy, young participants were scanned twice in each of 5 conditions; blood flow was measured using standard PET [15O]-water technology. Two major findings have replicated previous studies. First, the naming of visually presented objects, whether covert or overt, requires a region of the left inferior cortex including the fusiform gyrus. Second, during overt naming, there is an increase in activity in the inferior or frontal cortex and insula as a consequence of generating speech code. These data are consistent with other studies demonstrating the importance of the inferior temporal regions for semantic processing, and the frontal cortex for word form generation. (JINS, 1998, 4, 160–166.)

Two studies were conducted to examine the relationship of acculturation to neuropsychological test performance among (1) medically healthy, neurologically normal African Americans (N = 170); and (2) HIV positive (HIV+) subgroups of African Americans and Whites (Ns = 20) matched on age, education, sex, and HIV disease stage. Acculturation was measured through self report for all participants, and linguistic behavior (Black English use) was assessed in a subset of medically healthy individuals (N = 25). After controlling for the effects of age, education, and sex, medically healthy African Americans who reported less acculturation obtained lower scores on the WAIS–R Information subtest and the Boston Naming Test than did more acculturated individuals. Black English use was associated with poor performance on Trails B and the WAIS–R Information subtest. HIV+ African Americans scored significantly lower than their HIV+ White counterparts on the Category Test, Trails B, WAIS–R Block Design and Vocabulary subtests, and the learning components of the Story and Figure Memory Tests. However, after accounting for acculturation, ethnic group differences on all measures but Story Learning became nonsignificant. These results suggest that there are cultural differences within ethnic groups that relate to neuropsychological test performance, and that accounting for acculturation may improve the diagnostic accuracy of certain neuropsychological tests. (JINS, 1998, 4, 291–302.)

Studies of speed of cognitive processing in Parkinson's disease (PD) have yielded mixed results. This may relate in part to a differential effect on cognitive speed by the type of information to be processed. In the present study, we compared medication fasted, nondemented individuals with mild idiopathic PD (N = 26) with age-matched controls (N = 12) on a test requiring easy and hard same–different discriminations for verbal, quantitative, and spatial information, as well as on a traditional memory scanning paradigm. A voice-activated relay rather than a key press was used to eliminate the need for limb and finger movements. Simple reaction time and movement time were also measured in a task requiring subjects to move a hand held stylus to a designated target. The PD group performed as fast as the control group across all tasks except movement time. Thus, in our paradigm, the presence of PD alone does not predict cognitive slowing in the presence of motor slowing. (JINS, 1998, 4, 584–592.)

Cognitive deficits associated with neurologic disease or damage are quite common and they are known to negatively impact the lives of patients, caregivers and society at large. Unfortunately, documented effective rehabilitation of cognitive deficits is extremely scarce. In addition the concept of cognitive rehabilitation is usually viewed with tremendous skepticism. This pessimism is manifested in so many ways: It is found in the reluctance of skeptical physicians to refer patients to rehabilitation clinicians, it is seen in the reluctance of service payers to fund clinical efforts, it gets reflected in the graduate training programs which place cognitive rehabilitation in the lower echelons of curricular priorities, it underlies the dearth of funded programs in cognitive rehabilitation research, and it even permeates professional organizations and journals where “treatment studies” represent an extreme minority of presentations and articles. The most salient explanation for this therapeutic nihilism is the implicit belief that “everyone knows it doesn't work.”

Fourteen patients with body dysmorphic disorder (BDD) were assessed with neuropsychological measures, including tests of executive, mnestic, and motor functions. Performance in these patients was compared to 10 patients with obsessive-compulsive disorder (OCD), 14 patients with schizophrenia, and 24 normal controls. Findings indicated normal performance of the BDD group on measures of mnestic and motor function, but poor performance of this group on tests of executive function (p < .05). The overall performance of the BDD and OCD groups on the neuropsychological measures was similar, while the schizophrenic groups showed a wider spectrum of neuropsychological deficits to these groups. These findings are discussed in terms of current theories of executive functions and the possible relationship between BDD and OCD. (JINS, 1998, 4, 167–171.)

Impaired awareness of the effects of brain injury is a commonly observed and poorly understood finding in traumatic brain injury survivors. Nonetheless, impaired awareness has been identified as a major factor in determining outcome for traumatic brain injury survivors. Review of previous studies of impaired awareness in this patient population revealed a number of preliminary findings regarding the nature of this phenomenon. The present paper presents the results of 2 new studies with a total of 111 traumatic brain injury patients conducted to bring further clarity to this area. Findings confirmed and extended many results of previous investigations. Specific findings included patient overestimation of functioning as compared to family member ratings, patient report of greater physical than nonphysical impairment, greater patient–family agreement on specific ratings of patient functioning than on general ratings, greater agreement of family and clinician ratings of patient functioning with each other than with patient self-ratings, and partial disagreement of different methods of measuring impaired awareness. (JINS, 1998, 4, 380–387.)