Mental Speed

The impact of sex-specific personality traits has often been investigated for visuospatial tasks such as mental rotation, but less is known about the influence of personality traits on visual search. We investigated whether the Big Five personality traits Extroversion (E), Openness (O), Agreeableness (A), Conscientiousness (C), and Neuroticism (N) and the Autism Quotient (AQ) influence visual search in a sample of N = 65 men and women. In three experiments, we varied stimulus complexity and predictability. As expected, latencies were longer when the target was absent. Pop-out search was faster than conjunction search. A large number of distracters slowed down reaction times (RTs). When stimulus complexity was not predictable in Experiment 3, this reduced search accuracy by about half. As could be predicted based on previous research on long RT tails, conjunction search in target absent trials revealed the impact of personality traits. The RT effect in visual search of the accelerating "less social" AQ score was specific to men, while the effects of the "more social" decelerating Big Five Inventory factors agreeableness and conscientiousness were specific to women. Thus, sex-specific personality traits could explain decision-making thresholds, while visual stimulus complexity yielded an impact of the classic personality traits neuroticism and extroversion.

A 'flash' backward masking procedure was designed to overcome the problems that apparent movement cues create when measuring inspection time (IT). This was evaluated against the backward mask widely used in previous research. A significant increase in mean IT, together with subjects' responses to a post-experiment questionnaire about strategy use, confirmed the effectiveness of the flash masking procedure. Correlations between IT and WAIS-R IQ scores were consistent with previous findings;-0.6 for IT-Performance IQ but not significant for IT-Verbal IQ.

Background and Purpose Epilepsy is highly prevalent in developing African countries with significant morbidity, social stigmatization, poor quality of life and preventable mortality. There are scanty reports on the contributions of seizure variables like seizure types, frequency of seizures, duration of epilepsy, age at onset and anti-epileptic drugs to cognitive disturbances in Nigerian Africans. This study assessed the effects of seizure variables on the cognitive performances of patients with epilepsy. Methods The cognitive functions of 41 patients with epilepsy and 41 controls were assessed with a computerassisted cognitive test battery, Iron Psychology (acronym-FePsy) using the simple and complex reaction time tasks for mental speed, recognition memory test (RMT) for memory and continuous performance test for attention. Results The cognitive performances of the patients using complex reaction time and the recognition memory tasks were worse than those of the controls (p<0.05). The duration of treatment with anti-epileptic drugs negatively affected all cognitive domains assessed. The seizure frequency, duration of epilepsy and the use of phenytoin were associated with psychomotor retardation and impaired memory. Conclusions The seizure variables negatively affected cognitive performances of Nigerian patients with epilepsy. Cognitive assessment is recommended as part of regular evaluation of patients with epilepsy.

Neuropsychological impairments in HIV/AIDS have been extensively researched and reported in developed countries, usually reflecting the prominence of initial sub-cortical involvement and characterized by memory loss (usually impaired retrieval), general slowing of psychomotor speed and thought processes and impaired manipulation of acquired knowledge. 1,2 Memory impairment, both verbal and non-verbal, is characteristic of HIV-associated dementia. 3 During the early years of the HIV epidemic, cognitive symptoms were thought to be common even during the initial ABSTRACT: Background: Memory impairment, usually impaired retrieval of information, has been described in HIV/AIDS, especially among those with severe illness. Neuro-cognitive disturbances in HIV/AIDS have been linked to poor quality of life and medication adherence. This prospective, case-control study was designed to assess the verbal and non-verbal memory as well as the attention abilities of Nigerian Africans with HIV/AIDS and correlate their performances with their CD4+ T lymphocytes (CD4+) counts. Methods: A total of 288 randomly selected subjects, comprising 96 HIV-positive symptomatic patients, 96 HIV-positive asymptomatic patients and 96 HIV-negative controls, participated in the study. The subjects were age-, sex-, and level of education matched. The Recognition Memory Test and Choice Reaction Time tasks, components of the computer-assisted neuropsychological tests battery-the Iron Psychology 'FePsy' were used for cognitive assessments. Results: The mean memory scores of the HIV-positive asymptomatic subjects did not differ significantly from the controls (p>0.05) but the HIV-positive symptomatic subjects' scores were significantly lower than the controls (p<0.05). Both HIV-positive groups had psychomotor slowing and impaired attention (p<0.05). The HIVpositive subjects with CD4+ counts <200/µl and between 200 and 499/µl had significant memory impairment (p<0.001 and p<0.001 respectively) but there was no significant impairment among those with count ≥500/µl. Impaired ability for sustained attention was however present irrespective of the CD4+ level relative to controls (p<0.001). Conclusions: We concluded that there was no significant memory disturbance among HIV-positive asymptomatic subjects despite the presence of impaired attention and psychomotor slowing, and that the severity of immune suppression (as indicated by the CD4+ T lymphocytes count) is a strong determinant of cognitive decline in HIV/AIDS. RÉSUMÉ: Étude prospective cas-témoin du fonctionnement mnésique chez les patients atteints du VIH/SIDA. Contexte : Une atteinte de la mémoire, habituellement de la récupération de l'information, a été décrite chez les patients atteints du VIH/SIDA, spécialement chez ceux dont la maladie est sévère. Les perturbations neuro-cognitives dans le VIH/SIDA ont été associées à une faible qualité de vie et de fidélité à la médication. Cette étude prospective cas-témoin a été conçue dans le but d'évaluer la mémoire verbale et non verbale ainsi que l'attention chez des Africains Nigériens atteints du VIH/SIDA et d'évaluer s'il existe une corrélation avec le décompte des lymphocytes T CD4+ (CD4+). Méthodes : 288 sujets choisis au hasard, soit 96 patients VIH-positifs symptomatiques, 96 patients VIH-positifs asymptomatiques et 96 témoins VIH-négatifs ont participé à l'étude. Les sujets ont été appariés pour l'âge, le sexe et le niveau de scolarité. L'évaluation cognitive a été effectuée au moyen du Recognition Memory Test (RMT) et du Choice Reaction Time Tasks, qui font partie d'une batterie de tests neuropsychologiques informatisés, le Iron Psychology « FePsy ». Résultats : Les scores mnésiques moyens des sujets asymptomatiques VIH-positifs n'étaient pas significativement différents de ceux des témoins (p > 0,05). Cependant, les scores des sujets VIH-positifs symptomatiques étaient significativement plus bas que ceux des témoins (p < 0,05). Les deux groupes de patients VIH-positifs avaient un ralentissement psychomoteur et un déficit d'attention (p < 0,05). Les sujets VIH-positifs dont le décompte CD4+ était inférieur à 200/Ìl et entre 200 et 499/Ìl avaient une atteinte mnésique significative (p < 0,001 et p < 0,001 respectivement). Il n'existait pas d'atteinte significative chez ceux dont le décompte était ? 500/Ìl. Cependant, ils avaient un déficit de l'attention soutenue par rapport aux témoins (p < 0,001), quel que soit leur décompte CD4+. Conclusions : Il n'y a pas de perturbation significative de la mémoire chez les sujets VIH-positifs asymptomatiques, malgré la présence d'un déficit de l'attention et d'un ralentissement psychomoteur. La sévérité de la suppression immunitaire (basée sur le décompte des lymphocytes T CD4+) est un déterminant puissant du déclin cognitif chez les sujets atteints du VIH/SIDA.

On two occasions one year apart, the cognitive performance of 12 patients with presenile dementia Alzheimer type (ATD) and 14 with alcoholic Korsakoff syndrome (KS) was assessed both psychologically using the Christensen version of Luria&#39;s neuropsychological investigation and physiologically by measuring P300 (P3) and other long-latency auditory event-related potentials. All patients with ATD showed evidence of psychological deterioration and most also showed changes in auditory P3, whereas on all measures the KS group remained essentially unchanged. The extent of the changes in the ATD group varied, but in general those patients with most psychological deterioration also displayed the biggest changes in P3 wave form. There were two patterns of decline: a majority followed the traditional progressive course associated with Alzheimer disease; and in a minority, decline was slower. Methods for determining the rate of decline in individual patients with ATD, together with the progn...

Background and Purpose Epilepsy is highly prevalent in developing African countries with significant morbidity, social stigmatization, poor quality of life and preventable mortality. There are scanty reports on the contributions of seizure variables like seizure types, frequency of seizures, duration of epilepsy, age at onset and anti-epileptic drugs to cognitive disturbances in Nigerian Africans. This study assessed the effects of seizure variables on the cognitive performances of patients with epilepsy. Methods The cognitive functions of 41 patients with epilepsy and 41 controls were assessed with a computerassisted cognitive test battery, Iron Psychology (acronym-FePsy) using the simple and complex reaction time tasks for mental speed, recognition memory test (RMT) for memory and continuous performance test for attention. Results The cognitive performances of the patients using complex reaction time and the recognition memory tasks were worse than those of the controls (p<0.05). The duration of treatment with anti-epileptic drugs negatively affected all cognitive domains assessed. The seizure frequency, duration of epilepsy and the use of phenytoin were associated with psychomotor retardation and impaired memory. Conclusions The seizure variables negatively affected cognitive performances of Nigerian patients with epilepsy. Cognitive assessment is recommended as part of regular evaluation of patients with epilepsy.

Evidence from neuroimaging studies suggests that intelligence differences may be supported by a parietofrontal network. Research shows that this network is also relevant for cognitive functions such as working memory and attention. However, previous studies have not explicitly analyzed the commonality of brain areas between a broad array of intelligence factors and cognitive functions tested in the same sample. Here fluid, crystallized, and spatial intelligence, along with working memory, executive updating, attention, and processing speed were each measured by three diverse tests or tasks. These twenty-one measures were completed by a group of one hundred and four healthy young adults. Three cortical measures (cortical gray matter volume, cortical surface area, and cortical thickness) were regressed against psychological latent scores obtained from a confirmatory factor analysis for removing test and task specific variance. For cortical gray matter volume and cortical surface area, the main overlapping clusters were observed in the middle frontal gyrus and involved fluid intelligence and working memory. Crystallized intelligence showed an overlapping cluster with fluid intelligence and working memory in the middle frontal gyrus. The inferior frontal gyrus showed overlap for crystallized intelligence, spatial intelligence, attention, and processing speed. The fusiform gyrus in temporal cortex showed overlap for spatial intelligence and attention. Parietal and occipital areas did not show any overlap across intelligence and cognitive factors. Taken together, these findings underscore that structural features of gray matter in the frontal lobes support those aspects of intelligence related to basic cognitive processes.

As part of the Medical Research Council prospective study of the neurological and neuropsychological complications of human immunodeficiency virus (HIV) infection, long-latency event-related potentials were recorded in a cohort of homosexual and bisexual men. The latencies and amplitudes of the potentials, recorded from three scalp sites, were compared with the scores from neuropsychological tests of memory, attention, and concentration and with markers of immune function. The findings from 94 men were analyzed in the cross-sectional study of whom 47 were HIV seropositive without symptoms or signs of HIV type 1 (HIV-1) infection, 24 had progressed to the symptomatic stages of the disease, and 23 were persistently HIV seronegative. There were no consistently significant differences between the three subject groups in mean latencies and amplitudes of the P300 and N200 or in the numbers of abnormal P300 latencies. There were no significant correlations between either the neuropsychological tests scores or the immune measures (CD4 lymphocyte count and p2 microglobulin level) and the neurophysiological parameters. On repeated testing an average of 2 years later, there was no evidence of a significant trend towards deterioration in 30 HIVseropositive subjects who remained asymptomatic compared with 22 HIV seronegatives. These findings indicate that there is no neurophysiological evidence of cognitive dysfunction in the asymptomatic stages of HIV-1 infection.

Evidence from neuroimaging studies suggests that intelligence differences may be supported by a parietofrontal network. Research shows that this network is also relevant for cognitive functions such as working memory and attention. However, previous studies have not explicitly analyzed the commonality of brain areas between a broad array of intelligence factors and cognitive functions tested in the same sample. Here fluid, crystallized, and spatial intelligence, along with working memory, executive updating, attention, and processing speed were each measured by three diverse tests or tasks. These twenty-one measures were completed by a group of one hundred and four healthy young adults. Three cortical measures (cortical gray matter volume, cortical surface area, and cortical thickness) were regressed against psychological latent scores obtained from a confirmatory factor analysis for removing test and task specific variance. For cortical gray matter volume and cortical surface area, the main overlapping clusters were observed in the middle frontal gyrus and involved fluid intelligence and working memory. Crystallized intelligence showed an overlapping cluster with fluid intelligence and working memory in the middle frontal gyrus. The inferior frontal gyrus showed overlap for crystallized intelligence, spatial intelligence, attention, and processing speed. The fusiform gyrus in temporal cortex showed overlap for spatial intelligence and attention. Parietal and occipital areas did not show any overlap across intelligence and cognitive factors. Taken together, these findings underscore that structural features of gray matter in the frontal lobes support those aspects of intelligence related to basic cognitive processes.

Epilepsy is highly prevalent in developing African countries with significant morbidity, social stigmatization, poor quality of life and preventable mortality. There are scanty reports on the contributions of seizure variables like seizure types, frequency of seizures, duration of epilepsy, age at onset and anti-epileptic drugs to cognitive disturbances in Nigerian Africans. This study assessed the effects of seizure variables on the cognitive performances of patients with epilepsy. The cognitive functions of 41 patients with epilepsy and 41 controls were assessed with a computerassisted cognitive test battery, Iron Psychology (acronym -FePsy) using the simple and complex reaction time tasks for mental speed, recognition memory test (RMT) for memory and continuous performance test for attention. The cognitive performances of the patients using complex reaction time and the recognition memory tasks were worse than those of the controls (p<0.05). The duration of treatment with anti-epileptic drugs negatively affected all cognitive domains assessed. The seizure frequency, duration of epilepsy and the use of phenytoin were associated with psychomotor retardation and impaired memory. The seizure variables negatively affected cognitive performances of Nigerian patients with epilepsy. Cognitive assessment is recommended as part of regular evaluation of patients with epilepsy.

Evidence from neuroimaging studies suggests that intelligence differences may be supported by a parietofrontal network. Research shows that this network is also relevant for cognitive functions such as working memory and attention. However, previous studies have not explicitly analyzed the commonality of brain areas between a broad array of intelligence factors and cognitive functions tested in the same sample. Here fluid, crystallized, and spatial intelligence, along with working memory, executive updating, attention, and processing speed were each measured by three diverse tests or tasks. These twenty-one measures were completed by a group of one hundred and four healthy young adults. Three cortical measures (cortical gray matter volume, cortical surface area, and cortical thickness) were regressed against psychological latent scores obtained from a confirmatory factor analysis for removing test and task specific variance. For cortical gray matter volume and cortical surface area, the main overlapping clusters were observed in the middle frontal gyrus and involved fluid intelligence and working memory. Crystallized intelligence showed an overlapping cluster with fluid intelligence and working memory in the middle frontal gyrus. The inferior frontal gyrus showed overlap for crystallized intelligence, spatial intelligence, attention, and processing speed. The fusiform gyrus in temporal cortex showed overlap for spatial intelligence and attention. Parietal and occipital areas did not show any overlap across intelligence and cognitive factors. Taken together, these findings underscore that structural features of gray matter in the frontal lobes support those aspects of intelligence related to basic cognitive processes.

Evidence from neuroimaging studies suggests that intelligence differences may be supported by a parieto-frontal network. Research shows that this network is also relevant for cognitive functions such as working memory and attention. However, previous studies have not explicitly analyzed the commonality of brain areas between a broad array of intelligence factors and cognitive functions tested in the same sample. Here fluid, crystallized, and spatial intelligence, along with working memory, executive updating, attention, and processing speed were each measured by three diverse tests or tasks. These twenty-one measures were completed by a group of one hundred and four healthy young adults. Three cortical measures (cortical gray matter volume, cortical surface area, and cortical thickness) were regressed against psychological latent scores obtained from a confirmatory factor analysis for removing test and task specific variance. For cortical gray matter volume and cortical surface area...

An auditory discrimination paradigm was employed to elicit event-related brain potentials in 13 patients with Alzheimer's disease and 14 patients with multi-infarct dementia. The P300 latency was significantly prolonged in 12 patients with dementia compared with age-matched controls and showed a significant negative correlation with the score of Wechsler Adult Intelligence Scale (WAIS), especially with that of Digit Span subtest. There was no disease specificity. After physostigmine treatment, P300 latency decreased and WAIS score increased in 6 among 10 cases. A long-latency component of the event-related potential (ERP), especially P300, occurs when a subject attends and discriminates stimulus events which differ from one another along some dimension (for example intensity, duration or modality).' P300 has been reported to be associated with cognitive processing,2 and the temporal lobes including hippocampus and amygdala have been proposed as its possible generator sites.34 Thus, any factor which modifies the timing of neural mechanisms underlying perception and cognition may lead to changes in the morphology or latency of P300. There is a general consensus that P300 latency evoked by an auditory target stimulus increases with age by 1-0 to 1-8 m s per year for ages ranging from 20 to 80 years. Goodin et al'0 demonstrated that P300 latency in demented patients was significantly prolonged as compared with normal controls regardless of the aetiology of dementia. This finding has been supported by other subsequent studies.7" Furthermore, Goodin and Aminoff'2 distinguished between cortical and subcortical dementia by comparing each component of event-related potentials. The purpose of this study was to examine the utility of P300 as a diagnostic test of dementia both in Alzheimer's disease (AD) and in multi-infarct

Background:Memory impairment, usually impaired retrieval of information, has been described in HIV/AIDS, especially among those with severe illness. Neuro-cognitive disturbances in HIV/AIDS have been linked to poor quality of life and medication adherence. This prospective, case-control study was designed to assess the verbal and non-verbal memory as well as the attention abilities of Nigerian Africans with HIV/AIDS and correlate their performances with their CD4+ T lymphocytes (CD4+) counts.Methods:A total of 288 randomly selected subjects, comprising 96 HIV-positive symptomatic patients, 96 HIV-positive asymptomatic patients and 96 HIV-negative controls, participated in the study. The subjects were age-, sex-, and level of education matched. The Recognition Memory Test and Choice Reaction Time tasks, components of the computer-assisted neuropsychological tests battery- the Iron Psychology ‘FePsy’ were used for cognitive assessments.Results:The mean memory scores of the HIV-positiv...

Background:Memory impairment, usually impaired retrieval of information, has been described in HIV/AIDS, especially among those with severe illness. Neuro-cognitive disturbances in HIV/AIDS have been linked to poor quality of life and medication adherence. This prospective, case-control study was designed to assess the verbal and non-verbal memory as well as the attention abilities of Nigerian Africans with HIV/AIDS and correlate their performances with their CD4+ T lymphocytes (CD4+) counts.Methods:A total of 288 randomly selected subjects, comprising 96 HIV-positive symptomatic patients, 96 HIV-positive asymptomatic patients and 96 HIV-negative controls, participated in the study. The subjects were age-, sex-, and level of education matched. The Recognition Memory Test and Choice Reaction Time tasks, components of the computer-assisted neuropsychological tests battery- the Iron Psychology ‘FePsy’ were used for cognitive assessments.Results:The mean memory scores of the HIV-positiv...

An abnormally prolonged latency of the P 300 event-related potential has been reported in several types of dementing illnesses, including Parkinson's disease (PD). While some PD patients have dementia, a significant number of PD patients have less severe cognitive impairments. We examined the relationship between the auditory P 300 and a neuropsychological battery of 11 tasks in 43 PD patients. The quantitative relationship between the individual neuropsychological measures and the P 300 was examined using partial correlation and analysis of covariance techniques which controlled for age, education, and illness duration. The strongest correlations were between P 300 and both shortterm memory and visual perception. Global cognitive deficits do not appear to relate to the abnormal P 300 responses in PD: instead, specific aspects of cognitive decline accounted for the electrophysiological abnormalities. An abnormally long or absent P300 correlated with deficits on select cognitive tasks: those involving memory, visual perception, and abstract reasoning. The interactions between anatomical and neurochemical abnormalities in PD are discussed in light of the pattern of deficits seen in this study.

Thirty-six HIV-1-infected predominantly well-functioning subjects were followed up for one year by repeated neuropsychological, clinical neurological, neuroradiological, and immunological examinations. Changes in cognitive performance related to the severity of HIV-1 infection as well as to neuroradiological or immunological changes were studied. A decline in cognitive speed and flexibility was found in symptomatic subjects (ARC, AIDS). The impairment was especially pronounced in patients with progression of brain atrophy. These findings suggest a brain pathology underlying the cognitive decline in ambulatory outpatients with symptomatic HIV-1 infection. A practice effect was found in asymptomatic subjects (ASX, LAS) and in those with unchanged CT/MRI scans. No systematic relationship was found between

Thirty-six HIV-1-infected predominantly well-functioning subjects were followed up for one year by repeated neuropsychological, clinical neurological, neuroradiological, and immunological examinations. Changes in cognitive performance related to the severity of HIV-1 infection as well as to neuroradiological or immunological changes were studied. A decline in cognitive speed and flexibility was found in symptomatic subjects (ARC, AIDS). The impairment was especially pronounced in patients with progression of brain atrophy. These findings suggest a brain pathology underlying the cognitive decline in ambulatory outpatients with symptomatic HIV-1 infection. A practice effect was found in asymptomatic subjects (ASX, LAS) and in those with unchanged CT/MRI scans. No systematic relationship was found between

HIV-I infection may be complicated by a number of psychopathological conditions. While organic mental disorders, such as H1V-related psychosis and dementia, are late manifestations, mood disorders may occur during both asymptomatic and symptomatic stages of infection. The possible impact of brain involvement due to neurotropism of H1V-1 has not been investigated systematically in these latter conditions. The psychiatric caseness of HIV-seropositive individuals without AIDS and seronegative controls was assessed using a standardized clinical interview (Present State Examination). A comparison was made between individuals with and without psychiatric caseness using clinical, neuropsychological, and neurophysiological assessments. An increased prevalence of current psychiatric illness was found in subjects with early symptomatic HIV infection compared to those with asymptomatic infection and controls'. This couM not be attributed to psychiatric history, as well as to clinical and immunological markers of HIV infection, however, psychiatric caseness in early symptomatic infection was associated with marked neurophysiological changes, detectable by quantitative electroencephalography. Altogether, this study provided preliminary evidence that psychiatric symptoms in symptomatic but not asymptomatic HIV infection may be associated with subtle brain invoh,ement preceding the immunological and neurocognitive impairment characteristic for AIDS.

As part of the Medical Research Council prospective study of the neurological and neuropsychological complications of human immunodeficiency virus (HIV) infection, long-latency event-related potentials were recorded in a cohort of homosexual and bisexual men. The latencies and amplitudes of the potentials, recorded from three scalp sites, were compared with the scores from neuropsychological tests of memory, attention, and concentration and with markers of immune function. The findings from 94 men were analyzed in the cross-sectional study of whom 47 were HIV seropositive without symptoms or signs of HIV type 1 (HIV-1) infection, 24 had progressed to the symptomatic stages of the disease, and 23 were persistently HIV seronegative. There were no consistently significant differences between the three subject groups in mean latencies and amplitudes of the P300 and N200 or in the numbers of abnormal P300

We examined the contribution of perceptual processes to cognitive ability with respect to stimulus complexity, response mode, level of encoding, and attention. The participants were 124 university students. Stimulus complexity due to presenting both irrelevant and relevant information led to a substantial increase in correlation between reaction time and measures of cognitive ability. Two different response modes, correctness in brief exposures and motor response, yielded correlations of equal size. Three levels of encoding were compared. These were related to signal detection, stimulus discrimination, and stimulus identification. It was very interesting to find that the correlation of the level relating to stimulus discrimination exceeded the other correlations. The consideration of attention showed clearly that about 70% of the common variance of perceptual processes and cognitive ability were due to attentive processes and 30% to preattentive processes. D

To assess whether the movement artifacts reported in visual inspection time (IT) tasks were under metacognitive control, 29 subjects were tested on a dual-task paradigm in which IT was conducted in conjunction with a concurrent, attention-dominating task. The 17 subjects who reported movement artifacts on a simple IT task did not subjectively report them in the dual-task condition, despite their estimated ITs in the dual-task IT situation being lower than those of the 12 subjects who could not perceive apparent motion effects. Subjects who reported movement artifacts had significantly higher verbal ability, but were no different to control subjects on performance measures of ability, or on tests of attention. The IT-IQ correlation was higher for performance measures of ability, for ITs performed in the dual-task condition, and for subjects who had previously reported movement artifacts. With the disappearance of movement artifact reports when conscious attention is allocated predominantly to a concurrent, heavily IQ-loaded task, it is hypothesized that the reports of movement artifacts on IT tasks are largely the product of highverbal subjects describing processes that are typically preconscious, rather than examples of metacognitive processing.

An abnormally prolonged latency of the P 300 event-related potential has been reported in several types of dementing illnesses, including Parkinson's disease (PD). While some PD patients have dementia, a significant number of PD patients have less severe cognitive impairments. We examined the relationship between the auditory P 300 and a neuropsychological battery of 11 tasks in 43 PD patients. The quantitative relationship between the individual neuropsychological measures and the P 300 was examined using partial correlation and analysis of covariance techniques which controlled for age, education, and illness duration. The strongest correlations were between P 300 and both shortterm memory and visual perception. Global cognitive deficits do not appear to relate to the abnormal P 300 responses in PD: instead, specific aspects of cognitive decline accounted for the electrophysiological abnormalities. An abnormally long or absent P300 correlated with deficits on select cognitive tasks: those involving memory, visual perception, and abstract reasoning. The interactions between anatomical and neurochemical abnormalities in PD are discussed in light of the pattern of deficits seen in this study.

An abnormally prolonged latency of the P 300 event-related potential has been reported in several types of dementing illnesses, including Parkinson's disease (PD). While some PD patients have dementia, a significant number of PD patients have less severe cognitive impairments. We examined the relationship between the auditory P 300 and a neuropsychological battery of 11 tasks in 43 PD patients. The quantitative relationship between the individual neuropsychological measures and the P 300 was examined using partial correlation and analysis of covariance techniques which controlled for age, education, and illness duration. The strongest correlations were between P 300 and both shortterm memory and visual perception. Global cognitive deficits do not appear to relate to the abnormal P 300 responses in PD: instead, specific aspects of cognitive decline accounted for the electrophysiological abnormalities. An abnormally long or absent P300 correlated with deficits on select cognitive tasks: those involving memory, visual perception, and abstract reasoning. The interactions between anatomical and neurochemical abnormalities in PD are discussed in light of the pattern of deficits seen in this study.

Evidence from neuroimaging studies suggests that intelligence differences may be supported by a parietofrontal network. Research shows that this network is also relevant for cognitive functions such as working memory and attention. However, previous studies have not explicitly analyzed the commonality of brain areas between a broad array of intelligence factors and cognitive functions tested in the same sample. Here fluid, crystallized, and spatial intelligence, along with working memory, executive updating, attention, and processing speed were each measured by three diverse tests or tasks. These twenty-one measures were completed by a group of one hundred and four healthy young adults. Three cortical measures (cortical gray matter volume, cortical surface area, and cortical thickness) were regressed against psychological latent scores obtained from a confirmatory factor analysis for removing test and task specific variance. For cortical gray matter volume and cortical surface area, the main overlapping clusters were observed in the middle frontal gyrus and involved fluid intelligence and working memory. Crystallized intelligence showed an overlapping cluster with fluid intelligence and working memory in the middle frontal gyrus. The inferior frontal gyrus showed overlap for crystallized intelligence, spatial intelligence, attention, and processing speed. The fusiform gyrus in temporal cortex showed overlap for spatial intelligence and attention. Parietal and occipital areas did not show any overlap across intelligence and cognitive factors. Taken together, these findings underscore that structural features of gray matter in the frontal lobes support those aspects of intelligence related to basic cognitive processes.

Access the most recent version at doi: 1993 162: 604-610 The British Journal of Psychiatry M Fell, S Newman, M Herns, P Durrance, H Manji, S Connolly, R McAllister, I Weller and M Harrison time Mood and psychiatric disturbance in HIV and AIDS: changes over References http://bjp.rcpsych.org/cgi/content/abstract/162/5/604#otherarticles Article cited in: permissions Reprints/ permissions@rcpsych.ac.uk to To obtain reprints or permission to reproduce material from this paper, please write to this article at You can respond http://bjp.rcpsych.org/cgi/eletter-submit/162/5/604

Long latency auditory evoked potentials were recorded in 55 homosexual men infected with human immunodeficiency virus (HIV). Forty-one of these patients were asymptomatic from the infection and 14 had clinical signs of illness. Nine of the symptomatic patients were demented and 8 (6 of whom were demented) met other diagnostic criteria for acquired immunodeficiency syndrome (AIDS). Cerebral responses were recorded from Fz, Cz, and Pz electrode placements referred to linked mastoids and averaged separately to rare (2,000 Hz) and frequent (1,000 Hz) tones presented in a pseudorandom sequence. Electroencephalography (EEG) was performed in 54 of the patients and magnetic resonance imaging (MRI) or computed tomography (CT) was done in 14 (13 of whom were symptomatic from the infection). The latency of N1, P2, N2, and P3 components was delayed in HIV-positive patients compared to normal and this was particularly so for the N1, N2, and P3 components. These changes were more marked in those patients who were symptomatic from their infection, especially in those who were demented. They were, however, present to a lesser degree even in asymptomatic (Class 11) patients. Thus, 78% of the demented patients and 28% of nondemented patients had a delay in latency of at least one of the evoked potential components beyond the upper limit of our normal population. By contrast, the EEG was normal in all patients with asymptomatic HIV infection and most symptomatic patients, although 5 patients in this latter group had mild generalized slowing. MRI and CT findings were similarly nonspecific, particularly in the nondemented group. Our findings suggest that long latency auditory evoked potentials may be particularly useful in the evaluation of HIV-infected patients, possibly permitting the early recognition of HIV encephalopathy and identifying those patients with a worse prognosis or in need of more aggressive management; perhaps, also, recording these potentials will permit the course of this disorder, and its response to therapy, to be followed.

We have previously described the development and initial validation of a telephone administered cognitive test battery (TACT). This report investigates the retest reliability of the TACT battery between telephone administration and face-to-face administration and measures the concurrent validity of the test components against a standard test of cognitive ability, the WAIS-R UK . Data were collected on 27 participants aged 62-63 years. There was a two-to 10-month interval between time 1 (telephone) and time 2 (face-to-face) administration. Intra-class correlation coefficients for telephone versus face-to-face administration of the TACT were satisfactory for all component measures except for 'object rotation' and WAIS similarities. There was no evidence of systematic cheating on the telephone-administered test. Tests of concurrent validity showed stronger correlations for the TACT battery components with verbal tests rather than performance tests, as measured by the WAIS-R UK . A few administration difficulties are noted and recommendations for change are outlined. The TACT is a convenient assessment tool with potential for measuring cognitive change in epidemiological studies.

An abnormally prolonged latency of the P300 event-related potential has been reported in several types of dementing illnesses, including Parkinson's disease (PD). While some PD patients have dementia, a significant number of PD patients have less severe cognitive impairments. We examined the relationship between the auditory P300 and a neuropsychological battery of 11 tasks in 43 PD patients. The quantitative relationship between the individual neuropsychological measures and the P300 was examined using partial correlation and analysis of covariance techniques which controlled for age, education, and illness duration. The strongest correlations were between P300 and both shortterm memory and visual perception. Global cognitive deficits do not appear to relate to the abnormal P300 responses in PD: instead, specific aspects of cognitive decline accounted for the electrophysiological abnormalities. An abnormally long or absent P300 correlated with deficits on select cognitive tasks: those involving memory, visual perception, and abstract reasoning. The interactions between anatomical and neurochemical abnormalities in PD are discussed in light of the pattern of deficits seen in this study.

One hundred and six HIV-positive drug users were tested with a two-tone auditory evoked potential (AEP) task and a small battery of neuropsychological tests, to examine the relationship between the latency of the P300 component (P3) of the AEP, intellectual function, mood and drug use. Principal components analysis revealed a significant correlation between P3 latency and the first principal component (r = −0·43, P < 0·001). Varimax rotation generated three orthogonal components which we interpreted as intellectual performance, memory, and mood. Intellectual performance and self-reported mood were individually correlated with P3 latency, but memory was not (r = −0·36, P < 0·001; r = 0·23, P < 0·05; and r = −0·18, NS, respectively).  Subjects with symptomatic HIV disease had a higher correlation between P3 latency and intellectual performance than subjects with asymptomatic HIV disease and, among patients with symptomatic HIV disease, poorer memory was associated with a lower CD4 count. Opiate or benzodiazepine consumption did not correlate with poor intellectual performance, memory, or selfrated mood in our sample. These results indicate that there is a relationship between AEP latency and neuropsychological measures of intellectual function, and that it is influenced by subjective mood. Surprisingly, declared current drug use has no discriminable effect on these relationships.

The use of apparent motion cues to guide discriminations on the inspection time (IT) task has been taken to imply the vulnerability of IT to strategic processes by higher IQ subjects, and the questionable generality of the IT/IQ correlation. The current study examined verbal and non-verbal intelligence, personality and IT in 74 young adults, using light-emitting diodes to present IT, obtaining perceptual self-reports during IT itself. Forty-three (58 per cent) subjects in the sample reported using motion cues to guide IT discriminations; these subjects had faster ITs than individuals who did not use motion cues (t = 2.97, p < .005; effect size = .73). Cue users did not have higher verbal or non-verbal IQ than non-users. Although cue users were lower in neuroticism than non-cue users, this did not account for their faster ITs. Slower IT correlated with lower scores on a measure of non-verbal intelligence (r = -0.41, p < .001); the size of this correlation remained similar when the sample was divided into groups reporting the use of motion cues or not. Thus, despite motion cues enhancing performance on an IT task, the perception of these cues neither causes, nor reduces, the correlation between IT and IQ.

Although brain volumes calculated from magnetic resonance (MR) imaging have been found to correlate with IQ, the relationship between MR-derived brain volume and other mental processes has not been examined. Fifty normal-ability adults had their brain volume calculated using MR scanning, along with tasks measuring IQ, memory, and information-processing speed, and an auditory evoked potential (AEP) task. All MR scans were corrected for artefacts arising from inhomogenous coil response. Of the three AEP components measured, only P3 latency and amplitude were associated with measures of mental ability. Out of the 50 adults tested, 40 had usable MR records. Corrected for height and weight, total brain volume was associated with Full-Scale IQ (r = 0.32, P < 0.025); when this correlation was corrected for restricted range, the correlation increased to 0.66. Although there was no systematic pattern of associations between brain volume and individual measures of memory or information-processing speed for the bivariate correlations, adjusted R2s from exploratory multiple regression suggested that while information-processing speed shared 7% of test variance with brain volume, memory might account for 22%, and the complete test battery might account for as much as 32%. Our study therefore suggests a partial dissociation between mechanisms underlying intelligence, in that brain volume is associated with mental ability and memory, but not especially with information-processing speed.

To assess whether the movement artifacts reported in visual inspection time (IT) tasks were under metacognitive control, 29 subjects were tested on a dual-task paradigm in which IT was conducted in conjunction with a concurrent, attention-dominating task. The 17 subjects who reported movement artifacts on a simple IT task did not subjectively report them in the dual-task condition, despite their estimated ITs in the dual-task IT situation being lower than those of the 12 subjects who could not perceive apparent motion effects. Subjects who reported movement artifacts had significantly higher verbal ability, but were no different to control subjects on performance measures of ability, or on tests of attention. The IT-IQ correlation was higher for performance measures of ability, for ITs performed in the dual-task condition, and for subjects who had previously reported movement artifacts. With the disappearance of movement artifact reports when conscious attention is allocated predominantly to a concurrent, heavily IQ-loaded task, it is hypthesized that the reports of movement artifacts on IT tasks are largely the product of high-verbal subjects describing processes that are typically preconscious, rather than examples of metacognitive processing.

To examine the neuropsychiatric effects of infection with HIV, 220 drug users (27 HIV negative, 193 HIV positive) completed tests evaluating premorbid intelligence, memory, non-verbal performance, information processing speed, and mood. When these measures were compared cross- sectionally by the severity of HIV illness, symptomatic patients (in CDC stage IV) were impaired on Trails B, two-choice decision time, delayed recall of the Wechsler Logical Memory Test and most components of the Auditory Verbal Learning Test. These findings imply reduced capacity for concentration, speed of thought and memory. When 101 patients were retested a mean of 16 months after their initial assessment, performance on Trails A and B, Block Design and delayed recall of the Wechsler Logical Memory Test deteriorated more for patients at, or progressing within, CDC stage IV, than performance of patients at stage III. The results broadly correspond to the cross- sectional findings. However, there was a decline in all tests of memory function for the sample independent of clinical staging. This may be evidence of brain involvement before the appearance of other symptoms. Self-rated measures of mood did not change cross-sectionally, progressively, or interactively with time and stage of HIV illness, and cannot account for the changes in cognitive function observed. Change in drug use, similarly, does not account for the cognitive findings. Four (5%) of the retested subjects developed AIDS dementia complex, but most of the performance and memory impairments seen were subclinical despite the destructive neuropathology presumed to underlie intellectual decline in patients with HIV infection.