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PubMed2006

A comparison of cognitive structure in schizophrenia patients and healthy controls using confirmatory factor analysis.

There is evidence that cognitive task performance breaks down into the same broad domains in schizophrenia as in healthy populations. However, this does not mean that the domains are independent of one another or that the interrelationships among domains are the same between groups. We used confirmatory factor analysis (CFA) to compare the latent structure of a broad neuropsychological battery in schizophrenia patients (n = 148) and healthy controls (n = 157). Main analyses examined the fit of a hierarchical six-factor model, in which associations among the factors were assumed to reflect their strong shared relationship to a general cognitive ability factor. The model incorporated the factors of verbal comprehension, perceptual organization, verbal memory, spatial memory, processing speed, and executive/working memory. The hierarchical model provided a good overall fit to data from both groups. However multiple groups CFA revealed significant differences in factor loadings between groups, reflecting a more generalized latent structure of cognitive ability in schizophrenia. This was also evident in higher bivariate correlations among cognitive domain composite scores calculated from the observed test data. Cognitive ability, as reflected in test performance, appears to be more unitary in schizophrenia than in healthy subjects. This finding may have measurement and treatment implications.

Adult↗

PubMed2006

Cognitive deficits and levels of IQ in adolescent onset schizophrenia and other psychotic disorders.

Cognitive deficits have been found to be prevalent in early onset schizophrenia. Whether these deficits also characterise other early onset psychotic disorders to a similar degree is unclear, as very few comparative studies have been done. The primary purpose of this study was to compare the profile and severity of cognitive impairments in first-episode early onset psychotic patients who received the schizophrenia diagnosis to those diagnosed with other non-organic, non-affective psychotic disorders. The secondary purpose was to examine whether the profile of cognitive deficits, in terms of intelligence, executive functions, memory, attention and processing speed was global or specific. First-episode psychotic adolescents (N = 39) between the ages 11 and 17 years were included, 18 of whom were diagnosed with schizophrenia, and 21 with other non-organic, non-affective psychoses, using ICD-10 criteria. A healthy control group (N = 40) was included, matched on gender and age. Cognitive functions were assessed using WISC-III/R, the CANTAB battery, WCST, Trail Making B, fluency tasks, and Buschke's selective reminding task. A similar profile and level of impairment was found on measures of attention, executive functions, reaction time, and memory in the schizophrenic and psychotic adolescent groups. However, analyses of WISC-III factor profiles suggested that early onset schizophrenia patients may have more global IQ deficits than non-organic, non-affective psychoses when examined recently after illness onset. Compared to the deficits of adult schizophrenia described in the literature, the results suggest relatively spared simple reaction times in early onset patients.

Adolescent↗

PubMed2006

Ziprasidone-induced cognitive enhancement in schizophrenia: specificity or pseudospecificity?

OBJECTIVE: Ziprasidone may improve cognition in schizophrenia; however, this could be related to clinical symptom improvement, reflecting "pseudospecificity". We tested the hypothesis that ziprasidone improves cognition in the absence of clinical improvement. METHODS: We conducted a 12-week, open-label study of ziprasidone in 10 schizophrenia patients who met non-response criteria (<20% reduction in BPRS scores over 12 weeks). We conducted comprehensive cognitive testing and assessed change from baseline to end of study. RESULTS: We detected significant improvement on three measures of episodic memory (p<0.01) in these clinically non-responsive patients. Trend-level improvements were noted on tests involving processing speed and executive function. CONCLUSIONS: These data suggest that ziprasidone has cognitive benefits unrelated to an influence on other disease parameters.

Adolescent↗

PubMed2006

Reaction time of the Continuous Performance Test is an endophenotypic marker for schizophrenia: a study of first-episode neuroleptic-naive schizophrenia, their non-psychotic first-degree relatives and healthy population controls.

Sustained attention has been proposed as an endophenotype of schizophrenia, and consequently may be useful as a quantitative trait in genetic studies. In the present study, we used the continuous performance test (CPT) to measure sustained attention in 112 first-episode and neuroleptic-naive schizophrenic patients, 296 of their non-psychotic first-degree relatives, and 452 normal controls. Compared with controls, probands with schizophrenia showed worse performance on all measures of CPT. Parents, siblings and offspring of probands were also impaired on 'hit reaction time', an index of psychomotor processing speed of the correct response. Hit reaction time was also independent of the acute clinical features of the disease, indicating it is a trait rather than a state marker. Our findings supported the use of the hit reaction time measure of the CPT as an endophenotype marker for schizophrenia.

Adolescent↗

PubMed2006

Computer-assisted cognitive remediation in schizophrenia: what is the active ingredient?

An emerging body of research has shown that computer-assisted cognitive remediation, consisting of training in attention, memory, language and/or problem-solving, produces improvement in neurocognitive function that generalizes to untrained neurocognitive tests and may also impact symptoms and work functioning in patients with schizophrenia. The active ingredient of these interventions, however, remains unknown as control groups in these studies have typically included few, if any, of the elements of these complex behavioral treatments. This study compared the effects of an extended (12-month), standardized, computer-assisted cognitive remediation intervention with those of a computer-skills training control condition that consisted of many of the elements of the experimental intervention, including hours spent on a computer, interaction with a clinician and non-specific cognitive stimulation. Forty-two patients with schizophrenia were randomly assigned to one of two conditions and were assessed with a comprehensive neuropsychological test battery before and after treatment. Results revealed that cognitive-remediation training produced a significant improvement in working memory, relative to the computers-skills training control condition, but that there was overall improvement in both groups on measures of working memory, reasoning/executive-function, verbal and spatial episodic memory, and processing speed. Taken together, these findings suggest that specific practice in neurocognitive exercises targeted at attention, memory and language, produce improvements in neurocognitive function that are not solely attributable to non-specific stimulation associated with working with a computer, interacting with a clinician or cognitive challenge, but that non-specific stimulation has a salutary effect on neurocognition as well.

Adult↗

PubMed2025

Mediterranean and standard American diet consumption in psychosis and non-psychosis affective disorders groups: Symptoms and cognition.

UNLABELLED: Research supports an association between diet and health, and emerging evidence suggests that diet is associated with neuropsychiatric symptoms. However, no human study has examined an anti-inflammatory diet across rigorously defined psychiatric diagnoses and its associations with symptom severity and cognition. As inflammation is implicated in mental illness, we investigated adherence to the Mediterranean diet (MD), an anti-inflammatory diet, and the standard American diet (SAD), and examined cross-sectional relationships with psychiatric symptoms and cognition. METHOD: Participants included 54 individuals with psychotic disorders, 30 with non-psychosis affective disorders and 40 healthy controls. Participants underwent diagnostic interviews, PANSS symptom ratings, and MATRICS cognitive assessments. The self-report GBAQ was used to assess adherence to the MD versus SAD. RESULTS: The psychosis group was significantly more likely to consume the SAD than healthy controls (p = 0.007), with MD adherence predicting better working memory (r = 0.461, p < 0.001). In the non-psychosis affective disorders group, MD adherence predicted slower processing speed (r = -0.376, p = 0.049). In the non-psychosis affective disorders group, MD predicted reduced PANSS General Psychopathology scale (r = -0.449, p = 0.013), as well as the Activation (r = -0.362, p = 0.049), and Dysphoric Mood factors (r = -0.403, p = 0.027). DISCUSSION: This first-of-its kind study identified poor dietary choices in persons with psychosis, showing significantly lower symptoms and better cognition in association with the MD in transdiagnostic analyses. It supports the study of dietary interventions for prevention and treatment of psychiatric conditions.

Humans↗

PubMed2006

Neuropsychological changes in a large sample of liver transplant candidates.

One-hundred forty-eight pre-liver transplant candidates completed a psychological interview and brief neuropsychological testing. Assessment measures included the Repeatable Battery of Neuropsychological Status, Shipley Institute of Living Scale, Trail Making Test Parts A and B (TMT-A and TMT-B), and the Folstein Mini Mental State Exam. Participants in our sample scored in the Below Average range of functioning (mean score = 100; SD = 10) on measures of memory (mean = 89.51, SD = 17.43), attention (mean = 87.62, SD = 17.23), and spatial perception (mean = 88.69, SD = 20.39). Scores reflected moderate to severe impairment in organization and processing speed (TMT-B completion time in seconds: mean = 137.22, SD = 88.64). Controlling for the effects of prior education, MELD scores were strongly correlated with poorer performance on immediate and delayed memory subtests (both P < .01), as well as with diminished attentional capacity (P = .03). MELD scores also were significantly related to slower completion times on the TMT-A and TMT-B (both P < .05). Furthermore, independent sample t tests indicated that patients with higher MELD scores (>10) experienced significantly greater difficulty with executive functioning (P < .05) and delayed memory (P < .05) than those with lower MELD scores. Thorough evaluations of cognitive functioning are needed pretransplant to identify and treat cases of subclinical hepatic encephalopathy before daily functioning becomes significantly impaired.

Attention↗

PubMed2006

Neuropsychiatric profiles of patients with juvenile myoclonic epilepsy treated with valproate or topiramate.

In this cross-sectional study, the neuropsychiatric profiles of 42 patients with juvenile myoclonic epilepsy (JME) who were treated with valproate (VPA) or topiramate (TPM) in monotherapy were compared with the aim of verifying the relationship between cognitive dysfunction, psychiatric disorders, and factors related to epilepsy. Patients with JME taking VPA 500-1750 mg/day or TPM 50-175 mg/day were selected. For all patients, psychiatric profiles were evaluated with the Scheduled Clinical Interview, axes I and II (SCID I and SCID II), or the Brazilian version of the Schedule for Affective Disorders and Schizophrenia for School-Aged Children (K-SADS-PL). Neuropsychological measures included intellectual functions, attention, memory, executive functions, and language. Patients taking TPM exhibited worse neuropsychological performance on attention, short-term memory, processing speed, and verbal fluency functions related to frontal lobes, which may be dysfunctional in JME. Anxiety disorders were associated with lack of seizure control and having had more than 20 lifetime generalized tonic-clonic seizures.

Adolescent↗

PubMed1997

Aging and multiple cue probability learning: the case of inverse relationships.

Multiple Cue Probability Learning (MCPL) is an important cognitive ability for all age groups that, like other cognitive abilities, depends on information processing speed and working memory capacity--skills that have been found to decline with age. The relation between age and ability to learn direct and inverse probabilistic relationships was studied in two MCPL experiments involving subjects in three age groups. In the first experiment, subjects learned two three-cue tasks following the MCPL paradigm. In the first task, all cues had a direct relation (DR) with the criterion. In the second, one cue had an inverse relation (IR) with the criterion. In the DR task, older subjects were able to learn nearly as well as younger subjects. In the IR task, older subjects performed significantly worse than younger subjects due to an inability to use the inverse cue. In a second experiment involving the IR task, task information (TI) was given, that is, the relation between each cue and the criterion was explicitly described. This eliminated the need for subjects to discover the inverse relation on their own, thus reducing the burden on working memory. Provision of TI resulted in improved performance for the 20-30 and 65-75 year old groups, but not in the 76-90 year old group. Significant differences in performance among age groups remained. These results cannot be fully explained by differences in working memory capacity. It is suggested that flexibility of functioning also plays a role.

Adult↗

PubMed1999

Brief foveal masking during scene perception.

In the present experiment, participants were exploring line drawings of scenes in the context of an object-decision task, while eye-contingent display changes manipulated the appearance of the foveal part of the image. Foveal information was replaced by an ovoid noise mask for 83 ms, after a preset delay of 15, 35, 60, or 85 ms following the onset of fixations. In control conditions, a red ellipse appeared for 83 ms, centered around the fixation position, after the same delays as in the noise-mask conditions. It was found that scene exploration was hampered especially when foveal masking occurred early during fixations, replicating earlier findings. Furthermore, fixation durations were shown to increase linearly as the mask delay decreased, which validates the fixation duration as a measure of perceptual processing speed.

Fovea Centralis↗

PubMed1998

The influence of ondansetron and m-chlorophenylpiperazine on scopolamine-induced cognitive, behavioral, and physiological responses in young healthy controls.

BACKGROUND: There is evidence from animal and human experiments that learning and memory come under the separate influence of both cholinergic and serotonergic pathways. We were interested in learning whether serotonergic drugs could attenuate or exacerbate the memory-impairing effects of anticholinergic blockade in humans. METHODS: The selective serotonin 5-HT3 receptor antagonist ondansetron (0.15 mg/kg i.v.) and the serotonergic agent m-chlorophenylpiperazine (m-CPP; 0.08 mg/kg i.v.) were administered in combination with the anticholinergic agent scopolamine (0.4 mg PO) and compared to scopolamine alone in 10 young, healthy volunteers. Testing occurred on three separate days. RESULTS: As expected, i.v. administration of scopolamine induced significant impairments in episodic memory and processing speed; however, these scopolamine-induced cognitive deficits were not attenuated by pretreatment with i.v. ondansetron (0.15 mg/kg), nor were they exacerbated by administration of i.v. m-CPP (0.8 mg/kg) in addition to scopolamine; however, administration of i.v. m-CPP was followed by a significant increase of self-rated functional impairment, altered self-reality, and dysphoria ratings, and scopolamine's effect on pupil size was potentiated. CONCLUSIONS: Together, these results suggest that in young, healthy volunteers scopolamine-induced changes of cognitive performance are only minimally modulated by the serotonergic effects on ondansetron and m-CPP. Further studies with older controls are needed to test whether these findings may be influenced by age.

Adult↗

PubMed1999

The differentiation of DSM-III-R psychotic depression in later life from nonpsychotic depression: comparisons of brain changes measured by multispectral analysis of magnetic resonance brain images, neuropsychological findings, and clinical features.

BACKGROUND: Psychotic depression has been proposed as a distinct subtype of major depression. There is considerable evidence for this in younger patients, although the neuroimaging has been rudimentary. Volumetric imaging studies are required of consecutive cohorts of patients with depression. METHODS: Ninety-nine consecutive elderly patients were diagnosed with DSM-III-R major depression. Eighteen were psychotic, and 81 were not. Sixty-six patients were given a neuropsychological test battery, and 44 had a magnetic resonance imaging brain scan. A model integrating clinical, psychological, and neuroimaging findings for the explanation of delusion formation during depression is proposed. RESULTS: Psychotic depression was characterized by worse physical health, more family history of depression, a poorer response to antidepressant drugs, and more severe lowering of mood; however, the strongest predictors of the presence of delusions were diencephalic atrophy, reticular activating system lesions, brain stem atrophy, and left-sided frontotemporal atrophy. The psychotic patients had poorer performance on tests of frontal lobe function and mental processing speed. CONCLUSIONS: In the elderly, psychotic depression is etiologically, clinically, and neuroradiologically distinct, and has different treatment requirements, from nonpsychotic major depression.

Age Factors↗

PubMed1999

Age-related slowing of control processes: evidence from a response coordination task.

Normal aging is associated with slowing of performance mostly due to a slowed functioning of central response-related processes. In this paper we set out to discover whether slowing occurs also when the process controlling the coordination of responses is engaged by the task. To this end, we compared the mean-reaction time performance of two groups of subjects (young vs. elderly) in single- and dual-task experimental paradigm. The response coordination process is required only by the dual-task paradigm. The results indicate that, in the dual-task situation, the elderly are markedly slower than young subjects. The eventual relevance of information-processing speed in determining the cognitive performance of the elderly is considered in the discussion of the results.

Adult↗

PubMedDate not supplied

[Cognitions in eating disorders and their assessment].

UNLABELLED: Cognitions are of crucial importance in the -aetiology and the maintenance of eating disorders. Dysfunctional cognitions in eating disorders are related to body image, self-esteem and feeding. The aim of this paper is to review the actual knowledge in this area. First, we will display -cognitive models in eating disorders. Cognitive factors in -eating disorders are logical errors, cognitive slippage and conceptual complexity. Eating disorder patients seem to have a deficient cognitive development. Some cognitive models stipulate that eating disorder patients may develop organised cognitive structures schemas concerning the issues of weight and its implications for the self. These schemas can account for the persistence and for the understanding the "choice of the eating disorder symptomatology. Cognitive pheno-mena of interest are self-schema, weight-related schema and weight-related self-schema. The maintenance model of ano-rexia nervosa argued that, initially there is an extreme need to control eating which is supported by low self-esteem. The maintenance of the disorder is reinforced by three mechanisms: dietary restriction enhances the sense of being in control; aspects of starvation encourage further dietary restriction; concerns about shape and weight encourage restriction. The development and maintenance of bulimic symptomatology are explained by placing a high value on attaining an idealised weight and body shape accompanied by inaccurate beliefs. The cognitive model of specific family of origin experiences puts forward the development of -maladaptative expectancies for eating and thinness. Second, we discuss distortions in information processing. a) In feeding laboratories, bulimics show a wide range of caloric intake and a disruption of circadian feeding patterns. In overeating bulimics, large meals occurred mainly during afternoon and evening with high fat and carbohydrate intake, but the majority of meals were of normal size and frequency. Responsivity to food cues indicates that bulimics were more responsive to sight, smell and taste of their favourite binge food, and a greater responsivity was associated with increasing -cue salience. Eating disorder patients appear to have internalised a mediated social rule concerning "good food" and make drastic selections thus removing the possibility of choice of foodstuffs. b) Experimental processes: temporal factors in the processing of threat seem to be of importance in patients with high levels of eating psychopathology. There is no evidence for preattentive processing biases among anorectics. Changes in information processing speed after treatment were not linked to treatment condition or treatment response. c) Judgement and emotions: in eating disorder patients, distortions of depressogenic nature are found that influence the cognitive style; thoughts about eating, weight and shape are characterised by negative affective tone; negative emotions could account for bulimic behaviour; anxiety and distress are correlated to thought control strategies. Information treating seems to be impaired in a non-homogeneous way. d) Cognitive schemas are seriously maladaptive and not well investigated. In eating disorder patients, core beliefs are absolute, unconditional and dichotomous cognitions about oneself and the world. There are only few studies in this field moreover showing controversial results. Core beliefs can explain links between personality disorders and eating psychopathology. Pathological core beliefs have to be taken in to account because they influence the outcome and the efficacy of cognitive behavioural therapy. Third, the last part of this paper summarises actually available rating scales eva-luating distorted cognitions in eating disorders. There are different methods for evaluation: specific and non-specific self-report questionnaires, thought-sampling procedures, -methods derived from cognitive psychology. The Mizes Anorectic Cognition questionnaire (MAC) is a well-known self-rating scale with good psychometric properties. The revised form of the MAC appears to be an improvement in the area of internal consistency, sensitivity, and reliability. It is obvious that there is no particular rating scale referring to specific cognitions on food. IN CONCLUSION: the main result of this literature review reflects that the cognitive treatment in eating disorders is altered in a specific way on an emotional basis and on self-representation.

Attitude to Health↗

PubMedDate not supplied

Persistence of cognitive impairment in geriatric patients following antidepressant treatment: a randomized, double-blind clinical trial with nortriptyline and paroxetine.

Cognitive dysfunction is common in older persons suffering from a major depression. However, the degree to which this dysfunction is reversible with successful treatment of the depression remains uncertain. The present study examined the effects that treatment (randomized double-blind design) with either an SSRI (paroxetine) or a tricyclic antidepressant (nortriptyline) had on cognition in older depressed patients. The patients' performance was compared to that of a group of normal controls of similar age and education. Patients and controls were administered measures of working memory, information-processing speed, episodic memory and attention five times over the course of a 12 week trial. At baseline, the patients performed more poorly than the elderly controls on all cognitive measures. While the patients' performance did improve over the course of their treatment, the magnitude of this improvement did not exceed that produced in the elderly controls by practice alone. The same pattern of results was evident in both intent-to-treat and responder analyses. Thus, there was no evidence that the depressed patients' cognitive performance normalized after response to antidepressant therapy. Neither the patients' age at onset nor their baseline level of cognitive functioning influenced the amount by which their performance improved over the 12 week trial. There was no difference between paroxetine and nortriptyline in the amount of cognitive change associated with treatment. The present results suggest that cognitive dysfunction persists in older depressed patients even after their mood disorder has responded to antidepressant medications.

Aged↗

PubMed2001

Cognitive resources during sentence processing in Alzheimer's disease.

This study assessed sentence comprehension in Alzheimer's disease (AD) while minimizing executive resource demands. AD patients (n=17) and healthy elderly control subjects (n=17) were asked to detect a word in a sentence. Unbeknownst to subjects, the target word at times followed an incorrect grammatical or semantic agreement. Control subjects took significantly longer to respond to a target word when it immediately followed an agreement violation compared to a coherent agreement, a difference that was not evident when the target word followed the agreement by several syllables. AD patients did not demonstrate a discrepancy between a violation and a coherent agreement in the immediate vicinity of the agreement, but demonstrated a significant delay in their response to a target word when it followed an agreement violation--particularly a violation of a grammatical agreement--by several syllables. Analyses of individual patient performance profiles revealed the pattern of delayed sensitivity to agreements in a majority of AD patients. Correlation and regression analyses associated AD patients' sensitivity to agreement violations over an abnormally delayed time course with a measure of inhibitory control, although weaker associations were also evident with measures of planning and short-term memory. We hypothesize that difficulty understanding grammatically complex sentences in AD is related to slowed information processing speed that restricts the timely construction of a sentence's structure and limits inhibition of canonical sentence interpretations such as first-noun-is-subject.

Aged↗

PubMed2002

On the dissociation between clustering and switching in verbal fluency: comment on Troyer, Moscovitch, Winocur, Alexander and Stuss.

Troyer, Moscovitch, Winocur, Alexander and Stuss (Neuropsychologia 36 (1998) 499) used a procedure originally introduced by Troyer, Moscovitch and Winocur (Neuropsychology 11 (1997) 138) for distinguishing two different components of verbal fluency-clustering and switching-in frontal and temporal-lobe patients. Application of this procedure yielded results that suggested a frontal-lobe switching deficit, but intact 'clustering'. I demonstrate here that the proposed procedure may lead to incorrect conclusions because it does not allow an unambiguous dissociation between a general reduction in processing speed and a selective switching deficit. Some implications of this critique for inferences about the neurocognitive components involved in verbal fluency tasks are discussed.

Adult↗

PubMed2003

Deficits of memory, executive functioning and attention following infarction in the thalamus; a study of 22 cases with localised lesions.

The thalamus plays a crucial role in memory, executive functioning and attention. It remains, however, unclear whether thalamic structures have specific roles in each of these functions. We tested 22 cases of thalamic infarction, proven with MR imaging, using experimental and established neuropsychological tests. We performed a lesion-overlap study in standardised stereotactic space of patients sharing a certain deficit, corrected for the lesion distribution of patients without such deficits and determined the regions of interest using an atlas of the human thalamus. We checked for additional, non-thalamic, damage and for deficient comprehension and perception that would preclude interpretation of the results. Non-thalamic damage such as white matter lesions, hippocampal atrophy, sulcal widening and infarctions occur significantly more often in patients aged over 60. The patients with additional damage overlapped to a major degree with those who showed loss of orientation, or lack of comprehension of the test requirements. In the 10 patients judged 'clean', we observed a deficit of episodic long-term memory with relative sparing of intellectual capacities and short-term memory when the mammillo-thalamic tract was damaged. Lesions including the medial dorsal nucleus, midline nuclei and/or intralaminar nuclei accompany executive dysfunctioning. Reduced simple processing speed and attention are associated with age, but not with a particular structure in the thalamus. Complex attention deficits follow damage to the intralaminar nuclei.We conclude that the analysis of structure-function relationships must take into account extra-structure damage which may explain cognitive deficits. Separate thalamic structures are involved in memory, executive functioning and attention.

Adult↗