Current views of long-term memory presume that both the hippocampal complex and the neocortex play interactive, but separate, roles in the storage of memories. While the neocortex is considered the eventual and permanent store for our memories, the encoding of recently experienced events is thought to be initially dependent upon the hippocampus and closely related structures. Neuropsychological studies have demonstrated that damage to the medial temporal lobe results in a retrograde amnesia extending back in time, with better preservation of older memories. The converse pattern has been shown in patients with semantic dementia, who have focal atrophy of the inferolateral temporal neocortex, but relative sparing of the hippocampal complex (Graham & Hodges, 1997). Here we demonstrate that such patients can show relatively preserved new learning on a forced-choice recognition memory test (based on real and chimeric animals), while patients in the early amnestic phase of Alzheimer's disease show severely impaired learning on the same test. This result provides support for the view that new learning is primarily dependent upon the hippocampus and related structures. (JINS, 1997, 3, 534–544.)

Endogenous and exogenous shifts of attention were examined in nondemented patients with Parkinson's disease (PD). In the endogenous condition, an arrow was used to cue participants' attention to the possible location of an impending target, whereas in the exogenous condition, a brightened box was used to cue attention. Cues were either valid (i.e., the target appeared in the cued location) or invalid (i.e., the target appeared in a noncued location). The time between cue onset and target onset (stimulus onset asynchrony or SOA) was varied in each condition. The results indicated that PD patients were not differentially impaired in shifting attention at the shorter SOAs relative to normal controls. However, at longer SOAs, the PD patients demonstrated less of an effect from cueing than did the normal control participants. PD patients' differential effect from cueing was evident in both exogenous and endogenous conditions. These results suggest that PD patients may experience a rapid decay of attentional inhibition and do not support the notion that a decrement in processing resources underlies their attentional deficits. Moreover, these findings further support the notion that the basal ganglia may play an important role in attentional functions. (JINS, 1997, 3, 337–347.)

We tested the validity of the 48-Pictures Test, a 2-alternative forced-choice recognition test, in detecting exaggerated memory impairments. This test maximizes subjective difficulty, through a large number of stimuli and shows minimal objective difficulty. We compared 17 suspected malingerers to 39 patients with memory impairments (6 amnesic, 15 frontal lobe dysfunctions, 18 other etiologies), and 17 normal adults instructed to simulate malingering on three memory tests: the 48-Pictures Test, the Rey Auditory Verbal Learning Test (RAVLT), and the Rey Complex Figure Test (RCFT). On the 48-Pictures Test, the clinical groups showed good recognition performance (amnesics: 85%; frontal dysfunction: 94%; other memory impairments: 97%), whereas the two simulator groups showed a poor performance (suspected malingerers: 62% correct; volunteer simulators 68% correct). The two other tests did not show a high degree of discrimination between the clinical groups and the simulator groups, except in 2 measures: the 2 simulator groups tended to show a performance decrement from the last recall trial to immediate recognition of the RAVLT and also performed better than the clinical groups on the immediate recall of the RCFT. A discriminant analysis with the latter 2 measures and the 48-Pictures Test correctly classified 96% of the participants. These results suggest that the 48-Pictures Test is a useful tool for the detection of possible simulated memory impairment and that when combined to the RAVLT recall–recognition difference score and to the immediate recall score on the RCFT can provide strong evidence of exaggerated memory impairment. (JINS, 1997, 3, 545–552.)

This longitudinal study examines the sensitivity of 2 computerized neuropsychological tests, delayed matching to sample and paired associate learning, to early dementia of the Alzheimer type (DAT). Normal controls, patients in the early stages of DAT, and individuals with questionable dementia (QD) were studied. At 6 and 12 months after initial presentation, almost half of the QD group exhibited lower scores on the computerized subtests, maintaining their scores on standard testing. Over the same period NC subjects maintained their performance levels, while DAT patients continued to deteriorate. Linear discriminant function analyses of the computerized subtests at 6 and 12 months correctly classified 100% of the early DAT patients. Eighty-four and 79 percent of normal controls were correctly classified at 6 and 12 months respectively. Further development of these subtests for the detection of early dementia and the documentation of ongoing change in DAT is warranted. The findings are discussed in terms of the special sensitivity of these tests to the neuropathology of Alzheimer's Disease. (JINS, 1997, 3, 139–146.)

Arithmetical reasoning ability has been investigated in a group study of patients with unilateral cerebral lesions. Two series of 38 and 39 patients, who had suffered unilateral cerebral lesions of the right and left cerebral hemisphere, respectively, were investigated. They completed a neuropsychological battery that included a test of computation (Graded Difficulty Arithmetic, GDA; Jackson & Warrington, 1986), and a new test of numerical series completion (Arithmetical Reasoning Test, ART). Whereas the left-hemisphere lesion group were markedly more impaired on the GDA compared to both the right-hemisphere lesion group and a standardization sample, both lesion groups were equally severely impaired on the ART. It is suggested that the abstraction of numerical relations, which is essential to numerical series completion, relies on the integrity of the right hemisphere. A global model of arithmetic processing that incorporates these findings is proposed. (JINS, 1997, 3, 260–268.)

HIV+ subjects have shown impairment on tests of executive function including automatic attention and verbal tasks. Impairment of semantic priming in HIV patients would suggest a disruption of automatic semantic activation. We examined semantic priming in HIV+ individuals and HIV− control participants with no history of substance abuse, neurologic or psychiatric disorder unrelated to HIV. HIV+ participants were divided into cognitively normal and cognitively impaired subgroups on the basis of a neuropsychological battery of 15 tests. Participants were presented with English words and nonword letter strings and indicated if the stimulus was a word or nonword. The nonwords were orthographically and phonologically correct and were created by rearranging the letter sequence of words (“ulpit”). All words had an obvious antonym (“deep”); two-thirds were presented as sequential antonym pairs (“enter”–“exit”). There were no group differences in speed of response to nonwords, indicating no generalized reaction time deficit. While control and cognitively normal HIV+ participants showed an effect of priming on reaction time to correctly detected words, cognitively impaired HIV+ participants did not. The lack of semantic priming demonstrated by cognitively impaired HIV+ participants suggests that they have lessened activation of automatic semantic networks. (JINS, 1997, 3, 348–358.)

Learning to read and write generates new rules within the language processing systems. These new rules significantly change the manner in which some operations are performed. This finding was studied, by comparing the performance of literate and illiterate persons in several tasks. It was found that illiterate individuals (1) had difficulties in repeating pseudowords, (2) were worse at memorizing pairs of phonologically related words compared to pairs of semantically related words, and (3) were unable to generate words according to a formal criterion. Illiterate persons use strategies that are good for semantic processing, but inadequate for phonological analysis, while literate individuals are able to use several parallel running strategies. (JINS, 1997, 3, 444–450.)

A recent theory of ADHD predicts a deficiency in sense of time in the disorder. Two studies were conducted to test this prediction, and to evaluate the effects of interval duration, distraction, and stimulant medication on the reproductions of temporal durations in children with ADHD. Study I: 12 ADHD children and 26 controls (ages 6–14 years) were tested using a time reproduction task in which subjects had to reproduce intervals of 12, 24, 36, 48, and 60 s. Four trials at each duration were presented with a distraction occurring on half of these trials. Control subjects were significantly more accurate than ADHD children at most durations and were unaffected by the distraction. ADHD children, in contrast, were significantly less accurate when distracted. Both groups became less accurate with increasing durations to be reproduced. Study II: Tested three doses of methylphenidate (MPH) and placebo on the time reproductions of the 12 ADHD children. ADHD children became less accurate with increasing durations and distraction was found to reduce accuracy at 36 s or less. No effects of MPH were evident. The results of these preliminary studies seem to support the prediction that sense of time is impaired in children with ADHD. The capacity to accurately reproduce time intervals in ADHD children does not seem to improve with administration of stimulant medication. (JINS, 1997, 3, 359–369.)

This study compared postmeningitic children (N = 130) with grade and sex matched controls (N = 130) selected from target children's schools on measures of intellectual, linguistic, learning, and reading skills. Results showed that children with a history of meningitis are at greater risk for impairment in these areas, with experience of the disease prior to 12 months of age being an important risk factor. Within the postmeningitic sample presence of medical complications was associated with poorer verbal abilities. Finally, a significant relationship was identified between depressed language skills and later educational difficulty, with these findings interpreted with respect to both developmental and neuropsychological principles. (JINS, 1997, 3, 147–158.)

Journeymen painters were evaluated with a comprehensive battery of neuropsychological tests and compared to demographically similar nonexposed controls. For painters, a cumulative exposure to solvents was estimated from a structured interview that derived an index based on lifetime exposure and exposure in the past year. Painters were tested either shortly after having painted or after an exposure-free interval. Significant between-group differences were found on a cluster of tests measuring learning and memory. Within the painter group, scores on the learning and memory tests were significantly related to the interaction of condition and exposure. That is, those painters who were tested soon after painting and who also had a higher overall lifetime exposure, performed worst on tests of learning and memory. These results are consistent with the view that neuropsychological function — particularly learning and memory — may be compromised in active workers with a history of chronic solvent exposure. Furthermore, both the chronicity of solvent exposure, as well as the acuteness of the exposure, are significant factors in cognitive performance. (JINS, 1997, 3, 269–275.)

This is the third symposium to be published in JINS. The idea for the symposium arose following the presentation of a group of papers on pediatric head injury at the February 1996 meeting of the International Neuropsychological Society in Chicago. During that paper session, speakers shared not only their research data, but also the methodological and conceptual dilemmas involved in evaluating the consequences of head injury in children. Several of these dilemmas occur as themes throughout the set of articles presented in the symposium.

We studied the integrity of working memory operations in 38 HIV-seropositive and 20 seronegative drug users, using a modified version of the Tower of London task. This new task, the Tower of London–Working Memory version (TOL–WM), includes a delayed-response component in addition to the planning required for successful performance of the standard TOL. Symptomatic HIV-seropositive participants solved significantly fewer TOL–WM problems compared to matched seronegative controls. However, seropositive and seronegative subjects showed similar overall levels of planning efficiency, suggesting that the TOL–WM deficit may be associated primarily with failure to encode or maintain an adequate online memory representation. The results of this study confirm our previous report of a possible working memory deficit in HIV-1 infection and suggest that measures of working memory have particular utility in the evaluation of HIV-related cognitive deficits. (JINS, 1997, 3, 451–456.)

Despite considerable sparing of function following some forms of early brain disease, neural plasticity is far from complete. Many children with early brain insults, including those who sustain traumatic brain injury (TBI), are susceptible to both immediate and long-term neurobehavioral impairments. To introduce this symposium, the present article reviews existing research on the effects of 3 age-related factors on outcomes: age at injury, time since injury, and age at testing. Research findings support the hypothesis that development is more adversely affected the younger the child at the time of brain insult. Although we know less about how outcomes are related to the other developmental factors, there is little evidence that sequelae resolve with age. Potential brain mechanisms responsible for age-related differences are explored and methodological problems are considered. Emphasis is placed on the importance of prospective designs, measurement of developmental change, comprehensive assessments of outcome, and evaluation of factors contributing to variability in outcomes, such as premorbid status, type of brain injury, and environmental influences. Papers in this series demonstrate the utility of these methods and shed new light on developmental processes associated with childhood brain insults. (JINS, 1997, 3, 555–567.)

This study sought to determine if human immunodeficiency virus–type 1 (HIV-1) infected depressed men were more likely to be neuropsychologically impaired than their nondepressed counterparts. Subjects were 47 HIV-1 infected men who met DSM–III–R criteria for current major depressive disorder (MDD) and 47 HIV-1 infected nondepressed male controls (M age = 34.2 years) equated on HIV-1 disease severity, demographics, and drug use. The psychiatric interview included the Structured Clinical Inventory for the DSM–III–R, and Hamilton Rating Scale for Depression. The neuropsychological battery included tests covering 8 functional domains based on an expanded Halstead-Reitan Battery. The medical assessment included a history and physical examination, immunologic staging, and evaluation of prescription and recreational drug use. Prevalence of global neuropsychological impairment in the two groups (depressed vs. control) did not differ [53% vs. 38% respectively; χ2(1, N = 94) = 2.11, p > .05]. While syndromically depressed patients performed less well than nondepressed individuals on memory tests [delayed retention portions of the Story Memory Test: F(1,91) = 5.34, p < .05; and Figure Memory Test: F(1,90) = 4.16, p < .05], the majority of depressed participants (64%) did not have clinically impaired memory. No relationship between neuropsychological impairment and severity of depression was observed. The results suggest that, while HIV-1 infected men with major depression may perform more poorly than nondepressed men on some aspects of memory tasks, they are not more likely to evidence clinically significant neurocognitive impairment. (JINS, 1997, 3, 457–463.)

HIV infection often results in MRI-detectable brain atrophy and white matter signal hyperintensities (WMSHs). Magnetic resonance images were obtained from 31 HIV+ male patients and 10 high-risk controls. Variation within the HIV+ group on neuropsychological (NP) impairment and stage of systemic disease were relatively independent, allowing examination of the relative association of MRI measures with NP impairment versus with systemic stage of disease. HIV+ patients compared to high-risk controls evidenced global atrophy, reduced caudate nuclei volume, and a trend to gray matter volume loss but no difference in white matter volume or in WMSHs. These effects were progressive with CDC clinical stage such that patients at CDC stage A had values very close to those of controls, while patients at CDC stage C had the most abnormal values. In contrast, the relationship between these MRI variables and severity of NP impairment was much less dramatic, with the mildly to moderately impaired HIV+ subjects showing MRI volume effects greater than or equal to those of the severely impaired HIV+ subjects. These results suggest that MRI-detectable brain atrophy secondary to HIV infection is not the primary substrate underlying the progressive NP impairment in HIV disease. (JINS, 1997, 3, 276–287.)

Neuropsychological assessment has been extensively used in the presurgical evaluation of temporal lobe epilepsy (TLE) patients to assist in determining lateralization of seizure onset. Very few studies have examined the accuracy with which commonly used neuropsychological instruments provide this information in the individual patient. In 81 patients (49 right-, 32 left-TLE) without space-occupying lesions in whom correct seizure lateralization was inferred on the basis of postsurgical seizure-free status, we compared the frequency with which discrepancies between the Wechsler Memory Scale–Revised (WMS–R; Wechsler, 1987) Verbal and Visual Memory Indices, Warrington Recognition Memory Test (WRMT; Warrington, 1984) Words and Faces scaled scores, and Intracarotid Amobarbital Procedure (IAP) hemispheric memory scores correctly predicted seizure lateralization in the individual patient. Using both clinical analysis and discriminant function analyses (DFA), the IAP was found to be a clearly superior predictor of seizure laterality to the neuropsychological measures, whether used individually or in combination with one another. Using clinical analysis the WRMT was found to be a superior predictor to the WMS–R, which frequently gave false lateralizing information. Using all 3 measures in combination with one another, 87.1% of patients were correctly lateralized using DFA. Correctly lateralized patients were older and had longer durations of seizure disorder. (JINS, 1997, 3, 159–168.)

In 1985, Gualtieri and Hicks proposed the immunoreactive theory to explain the higher prevalence of childhood neurodevelopmental disorders in males. The theory claimed that male fetuses are more antigenic to mothers, resulting in increased immunologic attack on the developing central nervous system, and increased probability of atypical brain development. Individuals with systemic lupus erythematosus (SLE) provide a unique situation in which to investigate this theory. We evaluated the parent-reported prevalence of five developmental problems (stuttering, other speech problems, hyperactivity, attention deficit, and reading problems) in two groups: 154 individuals ages 8–20 years born to women with SLE, drawn from six cities, and 154 controls of comparable age and sex whose mothers did not have SLE. Controls were drawn from a comparison group ascertained from randomly selected schools in one of the cities. Questions about handedness, immune disorders, and pregnancy and birth complications were also evaluated. Children of SLE mothers were shown to have more evidence of developmental difficulties, immune related disorders, and nonrighthandedness. For developmental problems, these findings were most marked in male children of SLE mothers. These results suggest that maternal immunoreactivity, as represented by women with SLE, may present a special risk factor for subsequent learning difficulties in their children, particularly males. (JINS, 1997, 3, 370–376.)

It has been argued that young children's brains are “plastic,” and may sustain substantial brain insult with little loss of function. Recent research suggests that this notion may not apply for generalized cerebral pathology. The present study aimed to evaluate this proposition using a sample of 73 young children, divided into 3 groups: severe head injury (HI; N = 17); mild–moderate HI (N = 32); and noninjured controls (N = 24). Preinjury screening established equivalence across groups for age, sex, preinjury ability, behavioral adjustment, socioeconomic status, and family functioning. Children were evaluated as soon as possible postinjury, and again 12 months postinjury, in three domains: intellectual ability, language, and memory. Results indicated that severe HI was associated with substantial, persisting difficulties in all areas. In contrast, children with mild–moderate HI experienced fewer difficulties, and often performed similarly to controls, both acutely and 12 months postinjury. There was no evidence of differential recovery of function associated with injury severity, with performance increments consistent across groups and probably due to either age-appropriate developmental gains, or test–related practice effects. Poorer outcome at 12 months postinjury was predicted by injury severity primarily, with earlier age at injury, and premorbid ability associated with outcome in specific domains. (JINS, 1997, 3, 568–580.)

Objective: To examine the relationship between antiphospholipid antibody positivity (expressed as the lupus anticoagulant) and cognitive dysfunction in patients with systemic lupus erythematosus (SLE). Methods: Cross-sectional comparisons of lupus anticoagulant (LA) positive (N = 39) and negative (N = 79) patients and controls (N = 35) on a cognitive test battery; 22 LA-positive and 53 LA-negative patients who had never experienced neuropsychiatric events (never-NP–SLE) were also compared separately. Results: LA-positive patients were 2 to 3 times more likely than were LA-negative patients to be designated as cognitively impaired. As a group, LA-positive patients, particularly those in the never-NP–SLE group, demonstrated lower performance primarily on tasks of verbal memory, cognitive flexibility, and psychomotor speed. Conclusions: LA positivity is associated with subclinical nervous system compromise, and a pattern of deficits compatible with subcortical involvement, possibly on the basis of ongoing LA-related microthrombotic events or vasculopathy. (JINS, 1997, 3, 377–386.)

A traumatic spinal cord injury (SCI) is accompanied by a documented moderate to severe head injury in significant numbers of SCI patients. In a previous study (Dowler et al., 1995), cognitive deficits were found in 41% of the SCI individuals who were studied with a chronic injury from a traumatic event. The present study investigated whether clinically useful subtypes of normal and impaired cognition could be identified in a chronic (M = 17 years postinjury) SCI sample using a cluster analysis of neuropsychological test performance. A battery of 16 neuropsychological tests was administered to 91 SCI patients and 75 control participants. Composite scores, reflecting performance in different cognitive domains, were derived from a factor analysis of the battery, and these scores were then used in the cluster analysis. A six-cluster solution generated the most distinct and clinically relevant SCI group profiles. Two of the cognitive profiles were characterized by normal functioning in all cognitive domains, but they were distinguished by differences in performance levels. The remaining four SCI groups (60% of the sample) showed clinically significant deficits in one or more cognitive domains, with different groups showing moderate attention and processing speed deficits, mild deficits in processing speed, executive processing difficulties, or moderate memory impairments. Though age and premorbid intellectual ability were strong predictors of the cognitive profiles of some SCI groups, when these factors were controlled, the findings suggested that the patterns of cognitive impairment were likely due to a potential concomitant head injury. (JINS, 1997, 3, 464–472.)