The present study sought to delineate empirically derived memory subtypes using the California Verbal Learning Test (CVLT; Delis et al., 1987) in a sample of adults with HIV-1 infection (N 5 154). Confirmatory factor analysis was used to evaluate eight models of the CVLT structure suggested by Wiegner and Donders (1999). A four-factor model, consisting of Attention Span, Learning Efficiency, Delayed Recall, and Inaccurate Recall appeared to be the best fitting model. Variables with the highest factor loadings from the model were entered in a two-stage cluster analysis. Four reliable CVLT clusters or subtypes were identified: Normal, Atypical, Subsyndromal, and Frontal-striatal. Internal and external validation of subtypes demonstrated that clusters were stable and clinically interpretable. Subtypes were meaningfully related to neuropsychological functioning, and to some extent, depressive symptomatology. Subtypes did not differ significantly with respect to subjective neurocognitive complaints and markers of HIV-1 disease. The present findings highlight the heterogeneity of memory profiles in HIV-1 infection and support a frontal-striatal conceptualization of verbal memory performance. The identification of robust HIV-1 memory subtypes may have important implications for the clinical management of adults infected with HIV-1 infection. (JINS, 2003, 9, 1–16.)

To identify the cognitive characteristics predictive of incident dementia in Parkinson’s disease (PD), we examined the baseline neuropsychological profiles of 18 initially non-demented patients with PD who met diagnostic criteria for dementia (PDD) at one-year follow-up. PDD participants’ baseline neuropsychological test scores were compared to the baseline performance of 18 patients with PD who did not meet criteria for dementia at one-year follow-up (PDND) and 18 normal controls (NC). The three groups were matched on baseline demographic and disease variables. Relative to the PDND group, the incident PDD participants demonstrated significantly poorer performance on digits backward (Wechsler Memory Scale–Revised), word list learning and recognition (California Verbal Learning Test), and perseverative errors on the Wisconsin Card Sorting Test. Each of these baseline neuropsychological variables exhibited adequate diagnostic classification accuracy in predicting PDD and PDND group membership at follow-up. These results suggest that subtle frontal0executive dysfunction is evident during the immediate PDD prodrome and may be of prognostic value in identifying PD patients at risk for dementia. Accordingly, neuropsychological evaluation may facilitate early identification of PDD and thereby inform appropriate dispositional planning. (JINS, 2003, 9, 17–24.)

Efficient behavioral functioning requires early perceptual inhibition of irrelevant stimuli and later motor inhibition of inappropriate responses. The Perceptual and Motor Conflict Tasks were developed to differentially assess perceptual and motor inhibition, and to determine whether these processes utilize separate or shared cognitive resources. The computerized tasks include six subtests involving a box or an arrow appearing in various locations. Subjects respond by pressing a key on the left or right side of a keyboard. In different subtests, arrow direction or stimulus location determines correct responses. Perceptual inhibition assessment requires the subject to respond to a conflicting arrow direction while ignoring stimulus location. Motor inhibition assessment involves the subject responding in the direction opposite to that indicated by a centrally located arrow. In a neurologically normal sample (N = 44), reaction time analyses yielded significant Perceptual and Motor Conflict main effects, with slower performance under conflict conditions, but no significant Perceptual × Motor interaction. The lack of a significant Perceptual × Motor interaction, according to the additive factor model, indicates that these two processes utilize distinct cognitive resources. Nevertheless, performance on the two conflict tasks was significantly correlated with each other, and Perceptual Conflict performance was significantly correlated with Stroop interference. (JINS, 2003, 9, 25–30.)

Shallice and Burgess (1991) reported the utility of the Multiple Errands Test (MET) in discriminating executive deficits in three frontal lobe patients with preserved high IQ, who were otherwise unimpaired on tests of executive function. The aim of this study was to ascertain the value of a simplified version of the MET (MET–SV) for use with the range of people more routinely encountered in clinical practice. Main findings were as follows: 1) The test discriminated well between neurological patients and controls, and the group effects remained when the difference in current general cognitive functions (WAIS–R FSIQ) was taken into account. 2) The best predictors of performance in the healthy control group (n = 46) were age and the number of times participants asked for help (with more requests associated with poorer performance). 3) In the neurological group, two clear patterns of failure emerged, with performance either characterized by rule breaking or failure to achieve tasks. These two patterns were associated with different dysexecutive symptoms in everyday life. 4) The patients not only made more errors than controls, but also different ones. A scoring method that took this into account markedly increased test sensitivity. 5) Many patients passed traditional tests of executive frontal lobe function but still failed the MET–SV. This pattern was strongly associated with observed dysexecutive symptoms in everyday life. The results demonstrate the clinical utility of the test, and suggest that there are two common and independent sources of failure on multitasking tests in a general neurological population: memory dysfunction, and initiation problems. (JINS, 2003, 9, 31–44.)

The present study aimed to examine the clinical validity and applicability of the Chinese version of Mattis Dementia Rating Scale (CDRS) for elderly Chinese individuals. The scale was found to have good reliability with internal consistency ranging from 0.7 to 0.9. Its significant correlation with the Chinese version of Mini-Mental State Examination (CMMSE) suggested satisfactory construct validity of the scale. The discriminant validity of the CDRS in differentiating Alzheimer's disease (AD) patients and Normal Control (NC) elderly was also supported by the Receiver Operating Characteristics (ROC) analysis. Several cut-off points were presented for different clinical or research applications, and formulas to adjust for the age and educational level of the CDRS total score were provided. The Initiation/Perseveration and Memory subscales were suggested to be an abbreviated version of the CDRS for a quick screening. The present results also showed the association between the impairment of the CDRS performance and the progress of the AD. (JINS, 2003, 9, 45–55.)

Neuropsychological deficits are considered by many to be core features of schizophrenia. However, about 20% of patients with schizophrenia appear to have normal neuropsychological function. This study investigates this subgroup by comparing a “neuropsychologically normal” schizophrenia group to a non-schizophrenic, non-brain damaged patient comparison (PC) sample, and to patients with definitive brain damage who performed normally on neuropsychological testing. All patients completed the Halstead-Reitan Neuropsychological Test Battery and were classified as neuropsychologically normal or impaired using the Average Impairment Rating (AIR). In a sample of 113 patients with schizophrenia, 19.5% were classified as neuropsychologically normal. The brain damaged neuropsychologically normal group (BD-NN) consisted of 14.3% of 124 subjects. These groups were compared with a patient non-schizophrenic, non-brain damaged group who were selected on the basis of having an Average Impairment Rating in the neuropsychologically normal range. The neuropsychologically normal schizophrenic group performed less well than the non-brain damaged, non-schizophrenic patient comparison group on a number of tests, indicating that patients in this group may not be completely neuropsychologically normal, and would be better characterized as “high-functioning” or near normal. The results are discussed in regard to possible neurobiological differences between neuropsychologically impaired and intact schizophrenic patients, and implications for course and outcome. (JINS, 2003, 9, 56–63.)

In recent years, interest in the use of computerized neuropsychological (NP) assessment measures has increased. However, there are limited data regarding how performance on these measures relates to performance on more traditional, clinical instruments. In the present study, 82 HIV+ men, who were all believed on clinical grounds to have neurobehavioral impairment, completed a traditional NP battery (TNB) and the California Computerized Assessment Package (CalCAP, a collection of computerized reaction time tests). Summary scores based on a TNB, as well as those based on the CalCAP, demonstrated significant associations with both degree of immunosuppression (CD4 count) and detectable viral load in cerebrospinal fluid, but not with detectable viral load in plasma. Established norms on the TNB and CalCAP batteries resulted in classifying 57% and 49% of the HIV+ sample as impaired, respectively. When using the TNB as the “gold standard,” impairment classifications based on CalCAP summary scores exhibited a sensitivity of 68% and a specificity of 77%. Overall agreement on impairment classifications between batteries was low (kappa = .44). Data from this study suggest that traditional NP batteries and computerized reaction time tests do not measure the same thing, and are not interchangeable in examining HIV-related NP impairments. (JINS, 2003, 9, 64–71.)

Psychophysical functions are used to characterize both normal perception and altered perception among patients with neglect, yet the reliability of these functions is rarely examined. The present study examined two-week, test-retest reliability for power functions derived from line bisection data among 58 normal, young and old, male and female subjects. Power function exponents and constants were, at best, moderately reliable over time. The size of the exponent tended to decrease at retesting. Reliability coefficients varied by age and gender; they were highly significant for young men, marginally significant for older men, and non-significant for women. Race influenced reliability as coefficients were significant for Caucasian subjects but not for African American subjects. Age and gender effects in this study parallel those in the literature on pseudoneglect, and they may reflect hemispheric differences in visuo-spatial processing, magnitude estimation, or both. (JINS, 2003, 9, 72–78.)

Phonemic and semantic fluency involve the capacity to generate words beginning with particular letters or belonging to particular categories, respectively. The former has been associated with frontal lobe function and the latter with temporoparietal function, but neuroimaging studies indicate overlap of underlying neural networks. Schizophrenia patients may experience disproportionate semantic fluency impairment owing to abnormal semantic organization; however, executive dysfunction in schizophrenia suggests possible disproportionate phonemic fluency impairment. Moreover, little is known about the diagnostic specificity of either verbal fluency deficit to schizophrenia or their stability over time. We examined 83 schizophrenia patients, 15 bipolar disorder patients, and 83 normal controls. Both fluency types were impaired in schizophrenia patients. Schizophrenia patients as a whole manifested disproportionate semantic fluency impairment relative to bipolar disorder patients, but only a subset of schizophrenia patients manifested disproportionate semantic fluency impairment relative to controls. Few characteristics, except to some extent paranoid-nonparanoid subtype, meaningfully differentiated schizophrenia patients with and without this disproportionate impairment. Verbal fluency measures were moderately stable over a 4-year period in schizophrenia patients and controls (.48 < rs < .79). These results mirror a literature that overall suggests a small degree of disproportionate semantic fluency impairment in schizophrenia, but also some heterogeneity in fluency deficits. (JINS, 2003, 9, 79–88.)

The standardization sample from the WMS–III (N = 1250), which varied in age from 16 to 89, was used to determine whether encoding, retrieval, or storage of verbal and spatial information was most affected by normal aging. Immediate and delayed recall and recognition of Logical Memory and Visual Reproduction were examined. Immediate verbal and spatial recall significantly deteriorated with increasing age, and the age-associated deterioration in delayed recall and recognition was largely explained by poorer immediate memory. These findings, in concert with the smaller aging effects for percent retention after a delay, suggest that the aging effect is due to deterioration in encoding more than retrieval or storage of new information. While Visual Reproduction deteriorated more rapidly with age than Logical Memory, the pattern of performance decrements as a function of age were comparable across both tests. Decreases in performance were first seen in the fifth decade with gradual deterioration until the eighth decade when there was another precipitous drop. These results suggest that functions that are more dependent on the frontal lobes are more vulnerable to aging than those that are more dependent on the temporal lobes. (JINS, 2003, 9, 89–96.)

Age and gender effects on verbal episodic memory are well established. However, the possibility of interactions between age and gender has been raised by studies linking estrogen and verbal memory performance, and by research suggesting gender differences in age-related cortical atrophy. We evaluated whether age by gender interactions in verbal memory were present. Subjects within three years of the median age of menopause were excluded from a large cohort of normal subjects, resulting in a younger sample (16–47 years) of 288 men and 285 women, and an older sample (55–89 years) of 201 men and 245 women. All subjects were administered the CVLT-2, a multiple-trial list-learning task. Verbal memory was negatively correlated with age for younger men, older men, and older women, but not for younger women. Multivariate analyses indicated age by gender interactions on memory for the younger group but not the older group. Results indicate that verbal memory declines with age for younger men but not younger women, whereas both older men and older women show age-related declines. These findings are consistent with hypotheses linking estrogen and verbal memory performance, and with imaging data suggesting that age-related hippocampal atrophy is found in younger men but not younger women. The role of estrogen on cognition in normal aging warrants further study. (JINS, 2003, 9, 97–102.)

The exact role of the basal ganglia in both the motor and non-motor domains has proven elusive since it is virtually impossible to refer to its function in isolation of cortical, and especially frontal cortical circuits. The result is that we often speak of frontal-striatal circuits and functions but this still leaves us in the dark when trying to specify basal ganglia information processing. A critical review of the data from both basic science and clinical studies suggests that we should break down processing along a temporal continuum, including the domains of context, sequential information processing, and feedback or reinforcement (i.e., the consequences of action). This analysis would cut across other theoretical constructs, such as attention, central executive, memory, and learning functions, traditionally employed in the neuropsychological literature. Under specified behavioral constraint, the basal ganglia can then be seen to be involved in fundamental aspects of attentional control (often covert), in the guidance of the early stages of learning (especially reinforcement-based, but also encoding strategies in explicit paradigms), and in the associative binding of reward to cue salience and response sequences via dopaminergic mechanisms. Parkinson’s disease is considered to offer only a limited view of basal ganglia function due to partial striatal depletion of dopamine and the potential involvement of other structures and transmitters in its pathology. It is hoped that the present formulation will suggest new heuristic research strategies for basal ganglia research, permitting a closer link to be established between neurophysiological, functional imaging and neuropsychological paradigms. (JINS, 2003, 9, 103–127.)

Qualitative and quantitative performance on the Halstead Finger Tapping test may help differentiate brain dysfunctional patients from normal controls. “Normal” and “abnormal” finger tapping patterns during this task have been characterized and illustrated pictorially. Data from 65 patients with traumatic brain injury (TBI) and 15 normal controls support the dual proposition that (1) abnormal finger tapping patterns are more commonly observed in TBI patients than in controls and (2) the frequency of abnormal finger movements may relate to the severity of TBI during the acute stages after trauma. Future prospective studies are needed to replicate these findings. (JINS, 2003, 9, 128–133.)