Psychotic features associated with multiple sclerosis

Although once considered rare, several more recent investigations have been published describing psychotic features in multiple sclerosis (MS). The association between the two conditions, however, remains unclear. Large-scale hospital-based, epidemiological and case studies have suggested a relationship between psychosis and MS through demonstrating their higher than chance co-occurrence, their temporal relationship, and their association with particular structural abnormalities in the brain (i.e., periventricular white matter and temporal demyelination). The etiology of psychosis in MS has also not been explained adequately. Regional demyelination and the use of corticosteroids have been implicated, yet their mechanisms of action have not been elucidated. The present review addresses what is known at this point in time regarding the occurrence of psychosis in the context of MS, the data regarding possible etiological factors, and the implications of these data and suggestions regarding diagnosis and treatment. Future research should explore the underlying pathophysiology of psychosis and multiple sclerosis to further our understanding of the central nervous system disease process. This research could help determine the features which would guide clinicians in identifying patients at risk of developing psychosis in the context of MS, as well as propose the optimal pharmacological intervention.

Assessment and rehabilitation of cognitive impairment in multiple sclerosis

Patients with multiple sclerosis (MS) have a substantial risk of cognitive dysfunction, even in the earliest stages of the disease, where there is minimum physical disability. Despite the high prevalence rates and the significant impact of cognitive dysfunction on quality of life in this population, cognitive functions are not routinely assessed due to the high cost and time consumption. This article provides an overview of the current state of knowledge related to cognition in MS and on the optimal approach to neuropsychological assessment of this population. It then focuses on the pharmacological and other treatment options available for MS patients with, or at risk for developing, cognitive impairment. The available immune-modulating agents may reduce the development of new lesions and therefore prevent or minimize the progression of cognitive decline. However, there is currently insufficient evidence concerning the efficiency of symptomatic treatment in MS. There is also currently no optimal non-pharmacological treatment strategy for cognitive decline in MS, as the studies published to date report heterogeneous results. Nevertheless, non-pharmacological treatments such as cognitive rehabilitation may benefit some MS patients. As cognition is increasingly recognized as a major feature of MS, its assessment and rehabilitation will become a greater priority.

Assessment of Memory Skills in Illiterates: Strategy Differences or Test Artifact?

Previous studies have reported that illiterates perform more poorly than literates on a variety of neuropsychological measures. We investigated the hypothesis that putative memory deficits in illiterates are an artifact of the assessment tools used rather than a reflection of an 'underdeveloped' ability. In order to accomplish this, we designed two tests, a word list learning test and an object learning test. The illiterate group performed more poorly than semiliterate and literate groups on most variables of the word list learning test, but only on delayed recall and semantic clustering on the object learning test. Our findings suggest that poor memory performance among illiterates can be attributed both to the nature of the task, as well as to the use of different cognitive mechanisms to recall learned information. Presumably, formal education may enhance the innate ability of learning through training individuals in efficient learning and retrieval strategies. We emphasize the importance of developing and using ecologically valid neuropsychological tests to assess illiterate individuals.

Non-pulsatile circulation with axial-flow left ventricular assist device preserves neurocognitive function

Concerns about the potential impact of the non-pulsatile circulation pattern generated by the new generation axial-flow left ventricular assist devices on neurocognitive function led us to evaluate a patient in whom a Jarvik 2000 pump was implanted. We assessed the patient’s baseline neurocognitive function preoperatively as well as at 1-month and 6-month follow-up, using a comprehensive battery of neuropsychological tests. A slight improvement in circumscribed neurocognitive domains was noted, with no evidence of further decline at the end of a 6-month follow-up period.

Sex differences in neuropsychological functioning among schizophrenia patients

OBJECTIVES

Evidence from the literature addressing sex differences in cognition in schizophrenia remains equivocal, with some researchers suggesting that male schizophrenia patients are more impaired than female subjects, while others report no significant sex differences in cognitive functioning. The aim of the present study was to investigate whether the differential pattern of cognitive performance observed in healthy men and women is preserved in male and female schizophrenia patients.

METHOD

Ninety-six schizophrenia patients (56 men) were compared with 62 age- and gender-ratio matched healthy controls (31 men), on a battery of neuropsychological tests that assessed basic cognitive abilities: attention, working memory, abstraction, inhibition, fluency, verbal learning and memory, visual memory, visuospatial skills, and psychomotor speed.

RESULTS

As a group, schizophrenia patients were significantly impaired in each of the cognitive domains assessed, with the exception of psychomotor speed. The effect of sex was significant for verbal learning and memory, wherein women outperformed men. No significant group x sex interactions were found in any cognitive domains, indicating that the female advantage typically observed in verbal learning and memory remained the same in the schizophrenia patients.

CONCLUSION

The degree of cognitive impairment is the same for male and female schizophrenia patients. Those sex differences found among the patients were typical of the healthy population as well. Therefore, differential decrements in basic cognitive domains do not appear to account for the favourable course of schizophrenia in women relative to men.

Factor structure of the Greek translation of the Scale for the Assessment of Thought, Language and Communication

OBJECTIVE

The Scale for the Assessment of Thought, Language and Communication (TLC) is a widely used instrument for the assessment of formal thought disorder. TLC disorders were initially conceptualized as having only two underlying dimensions, a negative and a positive one. But studies of the factorial structure of the TLC have not provided confirmation for the positive-versus-negative distinction. The aim of the present study was to assess the factorial structure of the Greek translation of the TLC.

METHOD

Subjects were 103 patients (69 male, 34 female) with psychotic disorders randomly recruited from both inpatient and outpatient facilities. The TLC was assessed by two raters based on a 20 min clinical interview.

RESULTS

Principal component analysis with varimax rotation yielded a three-factor structure; the three factors consisted off items reflecting (i) disorganization of speech; (ii) peculiarities of speech; and (iii) verbosity. The disorganization factor could be further divided into two dimensions reflecting disturbances in the flow of ideas and in the structure of speech.

CONCLUSION

The investigation of the factorial structure of the Greek translation of the TLC scale found no support for the positive-versus-negative distinction of TLC disorders. Three factors (disorganization, speech peculiarities, and verbal productivity) were found to underlie the variance of the scale.

Impaired perception of affective prosody in remitted patients with bipolar disorder

Patients with bipolar disorder present deficits in facial emotion perception, both during a manic episode as well as upon recovery. Our goal in the present study was to investigate the ability of remitted patients with bipolar disorder to perceive affective prosody and to explore potential differences in the specific emotions that are troublesome for them. Participants included 19 patients with bipolar disorder I, currently in remission, and 22 healthy comparison subjects, matched on age, education, and gender. An affective prosody test (APT) was administered to all participants. Bipolar patients had significantly lower overall scores on the APT than healthy individuals. This impairment was specific to female patients and certain emotions (e.g., fear and surprise).

Ruff 2 and 7 Selective Attention Test: normative data, discriminant validity and test-retest reliability in Greek adults

Rapidly expanding interest in neuropsychological assessment in Greece has made the development of appropriate culture-specific normative data for core neuropsychological measures essential. In the present study, we sought to establish normative, test-retest reliability and discriminant validity data for the Ruff 2 and 7 Selective Attention Test in the Greek adult population. We administered the test using standard procedures to 218 healthy Greek adults (95 men), aged 17-80 years and two adult patient groups (26 detoxified opiate addicts and 23 HIV seropositive individuals). Using linear regression analyses, we examined the contribution of age, education and gender on Ruff 2 and 7 performance. We further examined test-retest reliability by administering the test on two occasions to 40 healthy adults, with an intersession interval of 12-14 weeks. The regression analyses revealed that age and education, but not gender, contributed significantly to participants performance, with older age and lower education contributing to poorer performance on Speed scores, but only education contributing moderately to Automatic Detection Accuracy scores. Test-retest reliability was very high (.94-.98) for Speed scores, and adequate to high (.73-.89) for Accuracy scores. Younger adults also demonstrated larger practice effects compared to older participants. The test appears to discriminate adequately between the performance of detoxified opiate addicts and HIV seropositive patients and matched healthy controls, as both patient groups performed more poorly than their respective control group. We present normative data for Speed and Accuracy scores stratified by age and education for the Greek adult population.

Humor appreciation deficit in schizophrenia: the relevance of basic neurocognitive functioning

The purpose in undertaking the present study was to investigate humor appreciation in patients with schizophrenia. Moreover, we sought to explore the potential relationship of humor appreciation with measures of psychopathology and cognitive functioning among the patients. Thirty-six patients with schizophrenia were compared with 31 normal controls matched for age, sex, and education on a computerized test comprising captionless cartoons: Penn's Humor Appreciation Test (PHAT). The patients were also evaluated on the symptom dimensions derived from the Positive and Negative Symptom Scale (positive symptoms, negative symptoms, cognitive symptoms, depression, and excitement), as well as a battery of neuropsychological tests measuring executive functions, attention, working memory, verbal and visual memory, visuospatial ability, and psychomotor speed. Patients with schizophrenia had significantly lower scores on the PHAT than normal controls. The patients' performance on the PHAT correlated with scores on Penn's Continuous Performance Test, the Stroop Color-Word Test, and the phonological subscale of the Greek Verbal Fluency Test. Our findings indicated impaired humor appreciation among patients with schizophrenia. The relationship found between the appreciation of captionless cartoons involved an incongruous detail and performance on a broad neuropsychological battery suggested that the deficit in humor appreciation in schizophrenia could be attributed to impairment in more basic neurocognitive domains, namely, selective and sustained attention as well as phonological word fluency.

Cultural Appropriateness of the Hooper Visual Organization Test? Greek Normative Data

Cross-cultural differences may affect performance on neuropsychological tests, even on those, which are non-verbal. We examined the appropriateness of the Hooper Visual Organization Test (HVOT) for use in the Greek population. In doing so, we sought to establish the internal consistency of its items, determine the influence of demographic characteristics on performance, create a normative database, and establish its ability to differentiate patient groups from healthy individuals for the Greek population. We administered the full test to 206 healthy adults in Greece (109 women), a group of 67 psychiatric patients with schizophrenia and a group of 31 neurological patients with multiple sclerosis. With respect to the healthy group, the reliability analysis of the 30-item scale yielded a Cronbach's alpha of .85, while item analysis was also very high for all items. Seventy percent of the items were perceived correctly by more than 60% of the sample. The remaining items yielded lower accuracy rates, which we attributed to their level of difficulty, rather than unfamiliarity (or low familiarity) in the Greek population. Regression analyses revealed that age and education level, but not sex, significantly influenced participants' performance, with older age and lower level of education contributing to poorer performance. Both patient groups performed more poorly on the test, compared to age- and education-matched healthy controls. Finally, we present norms for the Greek population according to age and level of education. The traditional form of the HVOT appears to be a reliable and valid neuropsychological tool for the Greek population.

Impaired emotion perception in schizophrenia: a differential deficit

We investigated previously reported contradictory findings regarding the nature of deficits in emotion perception among patients with schizophrenia. Some studies have concluded that such deficits are due to a generalized impairment in visual processing of faces, while others have found it to be restricted to facial emotional expressions. We examined 37 patients and 32 healthy controls, matched on age and education, using three computerized tests: matching facial identity, matching facial emotional expressions, and discrimination of subtle differences in the valence of facial emotional expressions. Our results showed impaired matching of emotions in patients with schizophrenia. This impairment did not manifest on tasks that depended on perceiving the identity of faces or cues of the relative valence of facial emotional expressions. Our findings support the differential deficit hypothesis of emotion perception in schizophrenia.

Shared cognitive processes underlying performance on the Wisconsin Card Sorting Test and the Stroop Test in patients with schizophrenia: a measurement artifact?

We explored the hypothesis that, while sensitive to different aspects of executive functioning in patients with schizophrenia, the Wisconsin Card Sorting Test (WCST) and the Stroop Test also measure the same construct, namely, inhibitory control. Specifically, our goal was to confirm and extend previous findings [A. Rossi, E. Daneluzzo, P. Mattei, M. Bustini, M. Cassachia, P. Stratta, Wisconsin Card Sorting Test and Stroop performance in schizophrenia: a shared construct, Neurosci. Lett. 226 (1997) 87-90] by demonstrating the independence of this construct from other abilities necessary to successfully perform the tasks. More importantly, we sought to improve on this previous study by eliminating the influence of the variance of speed of responding. We examined 55 patients with schizophrenia and initially found that performance on the Stroop Color-Word condition could, indeed, be predicted only by the percentage of perseverative errors on the WCST, and not variables reflective of other cognitive skills, thus replicating and extending previous findings. Once we removed the influence of speed of responding from our measure, however, thus isolating the inhibitory process, this finding disappeared. Therefore, our findings highlight the importance of isolating the individual components of interest from complex measures before drawing conclusions regarding the cognitive processes underlying particular test performance.

Impaired perception of affective prosody in schizophrenia

The authors aimed to explore schizophrenia patients' ability to perceive affective prosody. Specifically, certain emotions that may be more troublesome for patients and possible gender differences in prosody perception were assessed. Thirty six schizophrenia patients and 32 age-, education-, and gender-matched healthy comparison subjects assessed on an affective prosody test were examined. Patients were impaired on recognition of affective prosody overall, and their difficulties with prosody perception may be attributed to those emotions with negative valence, specifically anger and sadness. Findings revealed that only male patients were impaired on prosody perception. Deficits in the perception of affective prosody were principally evident in emotions with negative valence and male patients with schizophrenia. Future studies should explore the influence of these deficits on social and interpersonal functioning more directly.

Community dysfunction in schizophrenia: rate-limiting factors

The purpose of the present study was to investigate the impact of cognitive functioning, psychopathology, and severity of extrapyramidal side effects on community outcome in a group of Greek outpatients with schizophrenia. Participants were 40 outpatients with schizophrenia (25 men). Social adjustment was assessed with the Quality of Life Scale (QLS). Severity of symptoms of schizophrenia was measured with the Positive and Negative Syndrome Scale (PANNS), and extrapyramidal symptoms with the Extrapyramidal Symptom Rating Scale (ESRS). Finally, a battery of neuropsychological tests was administered in order to assess the following cognitive domains: executive functioning/set shifting, executive functioning/inhibition, fluency, verbal memory, visual memory, working memory, attention, visuospatial ability, and psychomotor speed/visual scanning. Total scores on the QLS were significantly correlated with negative symptoms, parkinsonism, and performance on the fluency tasks. Interpersonal relations subscale was significantly related with negative symptoms and fluency. No significant relationship was found between the Instrumental Role Functioning subscale and the PANSS, ESRS, or any cognitive domain. Scores on the Intrapsychic Foundation subscale were significantly correlated with negative symptoms and fluency. Finally, scores on the Common Objects and Activities subscale were significantly related with severity of negative symptoms, parkinsonism and visual memory. Our findings suggest that severity of negative symptoms, cognitive dysfunction, especially performance on fluency tasks and visual memory, as well as parkinsonism, are important determinants of functional outcome in schizophrenia.

Neuropsychological profile of cognitively impaired patients with schizophrenia

OBJECTIVE

Our purpose in undertaking the present study was to explore the existence of specific areas of cognitive deficits within the context of generalized poor performance in a group of Greek patients with schizophrenia. We also sought to identify any patients who might be cognitively normal.

METHOD

Participants were 70 patients with schizophrenia and 42 healthy control subjects. The 2 groups were matched on age and male-female ratio but differed in their level of education. A battery of neuropsychological tests was selected to assess executive functions/abstraction, fluency, verbal and spatial working memory, verbal and nonverbal memory, attention, visuospatial ability, and psychomotor speed.

RESULTS

Patients with schizophrenia performed more poorly than healthy control subjects, when we controlled for differences in level of education, on executive functions, working memory, verbal memory, nonverbal memory, fluency, visuospatial ability, and attention. In contrast, no significant differences were found between the 2 groups on psychomotor speed. Patients showed a more pronounced deficit on executive functions, verbal and visual memory, and visuospatial ability. Overall, 13% to 62% of the patients with schizophrenia scored within 1 SD of the mean z scores of healthy control group depending on the cognitive domains examined. In the entire sample of patients with schizophrenia, however, no individual scored within 1 SD of the mean z scores of the control group in all cognitive domains.

CONCLUSIONS

We found a generalized deficit in cognitive functioning in a group of patients with schizophrenia. We failed to find any individual patients who were healthy across all cognitive areas. The current neuropsychological profile, indicating widespread impairment, is comparable to that reported in the international literature and thus appears to be characteristic of schizophrenia. Our findings of increased difficulties with executive functions, verbal and visual memory, and visuospatial ability support previous suggestions of generalized brain dysfunction in the pathophysiology of schizophrenia.

Impaired emotion processing in remitted patients with bipolar disorder

In the present study, we examined whether there is an impairment in affect matching abilities in remitted patients with bipolar disorder and if this could be attributed to problems with facial perception per se and/or the ability to perceive the relative valence of facial expressions indicating emotions. We examined 19 patients with bipolar disorder I, currently remitted, and 30 healthy controls (15 men), matched on age, education, and gender, using two computerized tests: matching facial identity [Kinney's Identity Matching Test (KIMT)] and matching facial emotional expressions [Kinney's Affect Matching Test (KAMT)]. Patients with bipolar disorder performed significantly worse than the healthy group on the KAMT, but not on the KIMT. Performance on the KAMT and KIMT did not correlate with age of onset and duration of illness, or with manic or depressive residual symptoms. The present findings support the differential deficit hypothesis regarding impaired affect perception in bipolar disorder during remission. Patients' deficits were restricted to the matching of facial emotional expressions despite their intact perception of facial identity.

Lexical Processing in Illiteracy: Effect of Literacy or Education?

Difficulties in phonological processing in illiterates have been attributed to their limited phonological awareness, a consequence of their lack of literacy. We sought to explore the potential influence of education on auditory lexical processing above and beyond literacy per se. In order to achieve this goal, we compared a lexical decision making paradigm with a repetition paradigm using words and pseudo-words. We based this choice of tasks on previous research, which has shown that pseudo-word repetition is dependent on the phonological loop; such studies have thus demonstrated a literacy effect on repetition. Instead, lexical decision making is known to depend on the size of one's vocabulary, which is influenced by the level of education attained. Our sample comprised three groups: illiterate no education, literate/low education and literate/high education, individuals. The pattern of our findings confirmed that literacy has an effect on the capacity of the phonological loop, as our illiterate group alone had difficulty with repetition, as compared with both literate/educated groups. Also, our findings suggested an education effect on lexical decision making, as we found a gradation in the performance of the three groups. Therefore, we succeeded in dissecting the effect of literacy and education on auditory lexical processing through the application and comparison of two simple paradigms.

Closed head injury-related information processing deficits: An event-related potential analysis

Event-related potentials (ERPs) can elucidate aspects of sensory and cognitive processing that have been compromised due to closed head injury. We present the results of two investigations, one previously unreported, in which we used ERPs to evaluate information processing in head-injury survivors. In the first study, we used visual and auditory reaction time tasks differing in attentional demands to assess processing after head trauma. We found numerous changes in auditory processing in survivors: longer reaction times (but normal accuracy), longer N200 and P300 latencies, and reduced N100 and N200 amplitudes. In contrast, on visual tasks, only reduced N200 amplitude distinguished survivors and controls. To increase attentional demands, in a second study, we administered the continuous performance test (CPT). Survivors performed with lower accuracy than controls on visual and auditory tasks, and their ERPs were characterized by smaller visual and auditory N200s and P300s and smaller auditory N100s. We also present a synthesis, derived from a review of the literature, of closed head-injury effects on ERPs. Our own findings are in agreement with that synthesis. Namely, cognitive ERP components are more sensitive than sensory components to the effects of trauma. Specifically, in survivors, the amplitudes of N200 and P300 are often reduced, and their latencies prolonged. In general, as compared with visual ERPs, auditory ERPs may be more susceptible to the effects of closed head injury, suggesting that the auditory processing system is more vulnerable than the visual system. We conclude by discussing the potential use of ERPs to monitor clinical course and recovery in survivors of closed head injury.

Deficits in sustained attention in schizophrenia but not in bipolar disorder

The aim of the present study was to investigate sustained attention in remitted patients with bipolar disorder and in patients with schizophrenia, as compared to each other and to healthy controls; a secondary aim was to investigate the correlations of different symptom dimensions with performance on sustained attention in the two patient groups. Participants were 29 (18 men) outpatients with schizophrenia (SZ), 19 (8 men) patients with bipolar disorder I (BP) in remission, and 30 (15 men) healthy controls (HC); all three groups were matched on age, sex ratio, and level of education. Symptom severity (positive symptoms, negative symptoms, and general psychopathology) of patients with SZ were assessed with the Greek version of the Positive and Negative Syndrome Scale (PANSS); residual affective symptoms of patients with BP were assessed with the Young Mania Rating Scale (YMRS) and the Montgomery-Asberg Depression Rating Scale (MADRS). Sustained attention was measured by means of the Penn Continuous Performance Test (PCPT). The three groups differed significantly on the PCPT scores. Patients with SZ performed more poorly than both the BP and HC groups, whereas patients with BP did not differ significantly from HC. Performance on the PCPT did not correlate significantly with scores on the YMRS and MADRS in patients with BP. Also, scores on the PCPT did not correlate significantly with scores on any of the three subscales of the PANSS. Outpatients with schizophrenia presented deficits in sustained attention, whereas patients with bipolar disorder I in remission did not manifest such impairment. These results imply that impaired sustained attention might be a more enduring deficit in schizophrenia than it appears to be in bipolar disorder.

Verbal fluency in institutionalized patients with schizophrenia: age-related performance decline

Several studies have reported a relatively stable level of cognitive deficits among patients with schizophrenia regardless of age, while others have suggested continued deterioration with age. We compared the performance of 42 institutionalized patients with schizophrenia and 42 age- and education-matched healthy controls on a semantic and phonemic verbal fluency test. Each group was divided into young participants (<65 years old) and elderly participants (> or =65 years old). We found a fluency condition x diagnostic group x age group interaction on total words produced, a fluency condition x diagnostic group interaction on the number of cluster-related words, and a fluency condition x age group interaction on the number of switches. Patients with schizophrenia generally used similar strategies (i.e., semantic or phonemic cluster-related words and switches) as healthy individuals when generating words, but to a lesser degree. We found a disproportionate decline in the elderly schizophrenic patients relative to that of healthy controls only on the phonemic, relative to the semantic test. This decline in performance appears related to the effects of aging rather than severity or chronicity of illness, duration of institutionalization, or a progressive degenerative process associated with the disorder.

Disproportionate impairment in semantic verbal fluency in schizophrenia: differential deficit in clustering

The purpose of the current study was to investigate whether patients with schizophrenia present disproportionate impairment in semantic, relative to phonemic, fluency. Specifically, we explored whether this impairment could be explained by differential deficits in clustering or switching strategies. The Greek Verbal Fluency Test was administered to 119 patients with schizophrenia and 150 age-, education-, and gender-matched healthy controls. We calculated the total number of words generated, the number of cluster related words, and the number of switches on the semantic and phonological fluency tasks separately. Patients with schizophrenia generated fewer total words, cluster related words and switches than healthy controls on both fluency tasks. When controlling for the total number of words produced, however, the differences between the two groups in the number of cluster related words and switches disappeared. We found a disproportionate impairment in semantic, compared with phonemic, fluency in schizophrenia for total word production and the number of cluster related words, but not for the number of switches. In conclusion, patients with schizophrenia used the same strategies as healthy controls to perform on a word fluency test, but they used them less effectively. Disproportionate impairment in semantic fluency in schizophrenia resulted from a differential deficit only in clustering. Therefore, disproportionately impaired category fluency in schizophrenia may be primarily due to disorganization and not to inefficient access to and retrieval from semantic store.

Semantic and phonological processing in illiteracy

Researchers of cognitive processing in illiteracy have proposed that the acquisition of literacy modifies the functional organization of the brain. They have suggested that, while illiterate individuals have access only to innate semantic processing skills, those who have learned the correspondence between graphemes and phonemes have several mechanisms available to them through which to process oral language. We conducted 2 experiments to verify that suggestion with respect to language processing, and to elucidate further the differences between literate and illiterate individuals in the cognitive strategies used to process oral language, as well as hemispheric specialization for these processes. Our findings suggest that semantic processing strategies are qualitatively the same in literates and illiterates, despite the fact that overall performance is augmented by increased education. In contrast, explicit processing of oral information based on phonological characteristics appears to be qualitatively different between literates and illiterates: effective strategies in the processing of phonological information depend upon having had a formal education, regardless of the level of education. We also confirmed the differential abilities needed for the processing of semantic and phonological information and related them to hemisphere-specific processing.

Relationship between psychopathology and cognitive functioning in schizophrenia

The purpose of this study was to delineate the relationship between positive, negative, cognitive, depressive, and excitement symptom dimensions of schizophrenia and cognitive functioning. Fifty-eight patients with schizophrenia (DSM-IV criteria) were assessed using the Positive and Negative Syndrome Scale (PANSS) and a battery of neuropsychological tests (executive function/abstraction, verbal and spatial working memory, verbal and nonverbal memory/learning, attention, visuospatial ability, and psychomotor speed). The cognitive symptom dimension correlated with executive functions, attention, verbal memory, and spatial ability. Severity of the negative symptom dimension was related to impairment in the structure of the semantic knowledge system, verbal memory, and auditory attention. In contrast, severity of the positive symptom dimension correlated only with impairment in the structure of the semantic knowledge system, and psychomotor speed. Finally, severity of the depressive and excitement symptom dimension was not associated with cognition. Correlations between symptom dimensions and cognitive measures were at best modest. Severity of cognitive and negative symptoms was mainly correlated with deficits on executive functions, semantic memory, and verbal memory, while positive symptoms only with semantic memory. These correlations were modest, suggesting that psychopathology and cognitive deficits in schizophrenia are caused, at least partially, by distinct pathophysiological processes.

Relationship of affect recognition with psychopathology and cognitive performance in schizophrenia

The purpose of the present study was to explore the relationship between emotion perception and both psychopathology and cognitive functioning in a group of Greek patients with schizophrenia. Thirty-five patients with schizophrenia were assessed with computerized tests of emotion perception, using visual faces (Kinney's Affect Matching Test, KAMT), prosody (Affective Prosody Test, APT), and visual everyday scenarios (Fantie's Cartoon Test, FCT), as well as a facial recognition test (Kinney's Identity Matching Test, KIMT). The patients were also evaluated with the symptoms dimensions derived from the PANSS (positive, negative, cognitive, depression, and excitement) and a battery of neuropsychological tests measuring executive functions, attention, working memory, verbal and visual memory, visuospatial ability, and visual scanning/psychomotor speed. The three emotion perception and face recognition tests correlated significantly with each other. The KAMT was significantly related to the cognitive symptoms dimension of the PANSS and executive functions. The FCT was significantly related to level of education and attention. Finally, the APT was significantly related to the cognitive symptoms dimension, executive functions, and attention. Our findings regarding the significant relationships of affect perception, both facial and vocal, as well as in everyday scenarios, with several cognitive abilities support the notion that deficits in decoding affective information in schizophrenia could be attributed to impairment in more basic neurocognitive domains.