Emotion processing and theory of mind in schizophrenia patients and their unaffected first-degree relatives

Previous studies have suggested that social cognition is affected in individuals with schizophrenia. The purpose of this study was to explore to what extent social cognition deficits are shared by unaffected first-degree relatives, and the nature of the relationship between performance in different paradigms of social cognition. 20 Schizophrenia patients (7 females, 31 ± 10 years), 20 healthy age- and gender-matched individuals, 20 unaffected first-degree relatives of the schizophrenia patients (11 females, 50 ± 20 years), and 20 healthy individuals matched for age and gender were recruited. Patients showed deficits in the detection of social Faux Pas (0.80 ± 0.17 vs. controls: 0.94 ± 0.09, p = 0.025) and the correct identification of Theory of Mind stories (0.71 ± 0.13 vs. controls: 0.82 ± 0.12, p = 0.038). Relatives performed poorly in the Faces Test (0.83 ± 0.14 vs. controls: 0.9 ± 0.08, p = 0.048), the Reading the Mind in the Eyes Test (0.59 ± 0.17 vs. controls: 0.71 ± 0.14, p = 0.046) and the detection of social Faux Pas (0.8 ± 0.2 vs. controls: 0.93 ± 0.09, p = 0.024). Abnormalities were independent of age, years of education, and general cognitive performance in patients and their relatives. Performance in an Emotion Processing task (Faces Test) was correlated with performance in theory of mind tests in healthy individuals and relatives of patients with schizophrenia only. These results suggest that schizophrenia patients and their unaffected first-degree relatives display similar but nonidentical patterns of social cognition processing.     

Executive attention in schizophrenic males and the impact of COMT Val108/158Met genotype on performance on the attention network test

Background: Executive control of attention in schizophrenia has recently been assessed by means of the Attention Network Test (ANT). In the past, for tasks assessing executive attention, findings in schizophrenia have been contradictory, among others suggesting a lack of increased stimulus interference effects. Attention and executive functioning are substantially influenced by candidate genes of schizophrenia, including the functional single-nucleotide polymorphism catechol-o-methyltransferase (COMT) Val^108/158Met, with task-dependent, specific effects of Met allele load on cognitive function. Therefore, we aimed at investigating executive attention in schizophrenic patients (SZP) as compared with healthy controls (HC), and to assess the specific impact of COMT Val^108/158Met on executive attention, using ANT. Methods: We applied ANT to 63 SZP and 40 HC. We calculated a general linear model to investigate the influence of affection status and the COMT Val^108/158Met genotype on executive attention as assessed by the ANT. Results: Multivariate analysis of variance revealed a significant effect of group on executive attention. SZP exhibited smaller conflict effects in the ANT. Met allele load significantly modulated executive attention efficiency, with homozygous Met individuals showing low overall reaction time but increased effects conflicting stimulus information in executive attention. Conclusions: Our data suggest a disease-related dissociation of executive attention with reduced conflict effects in SZP. Furthermore, they support the hypothesis of differential tonic-phasic dopamine activation and specific dopamine level effects in different cognitive tasks, which helps interpreting contradictory findings of Met allele load on cognitive performance. Disease status seems to modulate the impact of COMT Val^108/158Met on cognitive performance.     

Longitudinal alterations of executive function in non-psychotic adolescents at familial risk for schizophrenia

Genetic diathesis to schizophrenia may involve alterations of adolescent neurodevelopment manifesting as cognitive deficits. Brain regions mediating executive function (fronto-striatal circuits) develop during adolescence while those supporting elementary aspects of attention (e.g. sustained focused attention) have a more protracted maturation beginning in childhood. We hence predicted that adolescents at risk for schizophrenia would show a failure of normal maturation of executive function. We prospectively assessed 18 offspring and 6 siblings of schizophrenia patients (HR) and 28 healthy controls at baseline, year-1 and year-2 follow-up using the Continuous Performance Test [visual-d′] and Wisconsin Card Sort Test (WCST). Perseverative errors on the WCST in HR remained stable but decreased in controls over the follow-up (study-group by assessment–time interaction, p = 0.01, controlling for IQ). No significant study-group by assessment-time interactions were seen for sustained attentional performance. HR may not improve while healthy subjects progressively improve on executive function during adolescence and early adulthood. Our results suggest an altered maturational trajectory of executive function during adolescence in individuals at familial risk for schizophrenia.     

Sex differences in cognition among persons with schizophrenia and healthy first-degree relatives

Previous research suggests differences between women and men in the clinical features of schizophrenia, but studies examining sex differences in neuropsychological functioning have reached inconsistent results. In the present study, sex differences in cognition and clinical features were investigated in population-based samples of participants with schizophrenia (n = 218), their healthy first-degree relatives (n = 438) and controls (n = 123). Sex differences in illness features were small; nevertheless, women with schizophrenia had less negative symptoms and lived independently more often than men. The schizophrenia group had impairments in all studied neuropsychological domains, and the relatives were impaired in processing speed and set-shifting. In all groups, women performed better than men in processing speed, set-shifting and verbal episodic memory, whereas men outperformed women in visual working memory. The group-by-sex interaction was significant in two variables: women outperformed men in the relatives group in immediate verbal reproduction and in the use of semantic clustering as a learning strategy, while there was no sex difference in the schizophrenia group. In conclusion, sex differences in cognition are mostly similar in schizophrenia to those among controls, despite sex differences in illness features. The preservation of sex differences also in first-degree relatives supports the conclusion.     

Vulnerability to schizophrenia. III: Importance and limits of the Identical Pairs Continuous Performance Test

Since several investigations have shown attentional deficits both in patients with schizophrenia and in subjects at high risk for schizophrenia, these deficits could be valuable vulnerability markers for schizophrenia. The aim of this study was to investigate wether non psychotic relatives of schizophrenic probands have deficits in sustained attention as measured by the Continuous Performance Test, Identical Pairs (CPT-IP) version. The study subjects were 25 schizophrenic probands, 50 of their first-degree relatives and 46 normal controls. For each subject, attention was assessed during 6 experimental conditions (2 standard, 2 slow, 2 easy conditions) of visual stimuli (digit-numbers and shapes). In each of the six conditions, the value of the sensitive index d' in the first-degree relative group was at an intermediate level between the patient and control groups. Moreover, in the standard shape condition, the d' value was significantly lower in the schizophrenic and in the relative groups than in the control group. This deficit was all the more interesting since it was not explained by a deficit in general intellectual abilities or by psychopathology such as anxiety or depression. Furthermore, the schizophrenic patients made more random errors in the standard and in the slow number conditions than both other groups. All groups improved their performance when the stimulus duration increased and when the processing load decreased. As a conclusion, this investigation seems: 1) to confirm the existence of an attentional deficit in the first-degree relatives of patients with schizophrenia; 2) to demonstrate the interest of the CPT-IP to detect this deficit. It must be emphasized that in order to detect the deficit, one only needs to explore the standard shape condition and that under such circumstances, the CPT-IP test has the advantage of being less time consuming than tests used in previous studies.     

首发精神分裂症患者神经认知功能的遗传学分析

目的 探索精神分裂症患者及其亲属共同存在的神经认知功能损害,并对22号染色体上儿茶酚氧位甲基转移酶(COMT)基因和脯氨酸脱氢酶(PRODH)基因的5个候选单核苷酸多态性(SNP)位点进行相关的遗传学分析。方法 采用14个神经心理测验(共29项)对235例首发精神分裂症患者(患者组)、322名未患病亲属(亲属组)和133名正常对照(正常对照组)进行有关智力、注意、记忆、言语功能和执行功能等评定,比较各组间的神经认知功能有无差异,并对上述神经认知功能测验与COMT和PRODH基因的5个候选SNP进行定量性状的传递不平衡测试。结果 (1)患者组所有测验的成绩均差于正常对照组,差异有显著性(P<0.01和P<0.05),而亲属组的记忆、注意、言语功能和执行功能界于患者与正常对照之间;(2)PRODH1 195G/A与即刻逻辑记忆测验(P=0.03)、言语流畅性测验的正确数(P=0.03)和连线测验B的犯规数(P=0.01)相关,PRODH1945G/A与数字符号测验(P:0.01)、连线测验A的错误数(P:0.02)、HANOI塔测验的总分(P=0.01)、威斯康星卡片分类测验(WCST)的总错误数(P=0.01)、WCST的非持续错误数(P:0.02)和WCST的总分类数(P=0.02)相关。结论 精神分裂症患者在记忆、注意、言语功能和执行功能等方面存在广泛的神经认知功能损害,这种损害可能是精神分裂症的遗传“内表     

Vulnerability to schizophrenia: neuropsychological performance and schizotypal personality traits]

Although some neuropsychological deficits and a high rate of schizotypal personality disorders have been found in the first-degree relatives of patients with schizophrenia, few studies have looked for a link between those two types of potential marker of vulnerability to this disease. The aims of this study were: 1) to confirm some executive/attentional deficits in a group of first-degree relatives including not only siblings but also parents; 2) to evaluate the schizotypal traits using the French version of 4 self-reporting scales proposed by Chapman and his colleagues; 3) to look for a dependence or independence between the neuropsychological performance and the scores on the scales of schizotypy. Twenty four patients with schizophrenia, 48 of their first-degree relatives and 31 controls were included in the study. Both attentional tests (a Digit Symbol Substitution Test and a Degraded Stimulus-Continuous Performance Test) confirmed a worse performance in the patient and in the first-degree relative groups than in the control group. On the opposite side, the executive performance assessed by the Wisconsin Sorting Card Test, was poorer in the patient group only. Scores of the first-degree relative group on the social anhedonia, physical anhedonia and perceptual aberrations scales were at an intermediate level between those of the patient and control groups; moreover, only scores on the social anhedonia scale tended to be significantly higher in the first-degree relative group than in the control group. Among the first-degree relative group, the only significant correlation found was between the number of perseverative errors on the WCST and the scores on the physical anhedonia scale.     

Impaired working speed and executive functions as frontal lobe dysfunctions in young first-degree relatives of schizophrenic patients

The aim of the investigation was to detect neuropsychological markers, such as sustained and selective attention and executive functions, which contribute to the vulnerability to schizophrenia especially in young persons. Performance was assessed in 32 siblings and children of schizophrenic patients and 32 matched controls using Wisconsin Card Sorting Test, Colour-Word-Interference-Test, Trail Making Test, and d2-Concentration-Test. The first-degree relatives showed certain impairments on all four tests, in particular, slower times on all time-limited tests. These results suggest the need for more time when completing neuropsychological tasks involving selected and focused attention, as well as cognitive flexibility, as a possible indicator of genetic vulnerability to schizophrenia.     

Dimensions underlying psychotic and manic symptomatology: Extending normal-range personality traits to schizophrenia and bipolar spectra

Objective

Covariance among psychiatric disorders can be accounted for by higher-order internalizing, externalizing, and psychosis dimensions, but placement of bipolar disorder within this framework has been inconsistent. Moreover, whether deviations in normal-range personality can explain psychosis and vulnerability to severe mood lability, as seen in schizophrenia and bipolar disorder, remains unclear.

Methods

Exploratory factor analysis of interviewer-rated clinical symptoms in patients with schizophrenia or bipolar disorder, their first-degree biological relatives, and nonpsychiatric controls (total N = 193), followed by examination of associations between symptom dimensions and self reports on personality questionnaires.

Results

Covariance in symptoms was accounted for by five factors: positive symptoms of psychosis, negative symptoms of psychosis, disorganization, mania, and depression/anxiety. Schizophrenia and bipolar patients/relatives reported elevated negative emotionality and absorption and lower positive emotionality relative to controls. Personality did not differ between schizophrenia and bipolar patients/relatives, but there was a different pattern of associations between symptoms and personality in these groups.

Conclusions

Discrete dimensions reflecting psychotic, manic, and depressive symptoms emerge when a broad set of clinical symptoms is examined in a sample overrepresented by psychotic experiences and affective disturbances. Although normal-range personality traits index common phenotypes spanning schizophrenia and bipolar spectra, the same symptoms may carry different significance across disorders.     

A comparison of euthymic bipolar patients with unaffected first-degree relatives and healthy controls in terms of neuropsychological functions

Objective. Cognitive dysfunction in bipolar disorder (BD) is well established in the literature. The neurocognitive deficits have been considered to be endophenotypic markers of BD, and studies have examined whether neurocognitive deficits exist in first-degree relatives of individuals with BD I. We hypothesized that performance in tests of neurocognitive function would be impaired in euthymic BD I patients and their unaffected first-degree relatives compared to that of healthy controls. Methods. We compared the performance of bipolar patients, their first-degree relatives, and healthy controls in a battery of neurocognitive tests to reveal possible endophenotypes of BD. A diagnostic interview and neuropsychological test battery were administered to 30 BD I patients, 55 of their unaffected first-degree relatives and 32 healthy controls. Results. The patients and their first-degree relatives were significantly impaired in executive function assessed using the Wisconsin Card Sorting Test (WCST) and Trail Making Test-B (TMT-B) relative to the controls (WCST; perseverative errors: p < 0.0005, categories completed: p = 0.002, TMT-B; p = 0.002). There were no significant differences between the groups in terms of attention, psychomotor speed, verbal memory, or learning. Conclusion. Our study suggests that the deficits in executive function may be endophenotypic markers of genetic vulnerability to BD I.     

Neural correlates of the attention network test in schizophrenia

Attentional deficits are prominent in schizophrenia, affecting nearly all cognitive functions. Human attention comprises three essential components: alerting, orienting and executive control. For the assessment of these functions, the attention network test (ANT) has been proposed and used in healthy controls and patients. In schizophrenia, the ANT has revealed behavioral deficits; however, the corresponding neural correlates have not been examined. In the present study, neural correlates of attention were investigated in 17 schizophrenia patients and 17 healthy controls using the ANT with fMRI. Behavioral deficits emerged in the alertness system with a reduced efficiency for temporal cues. In fMRI, changes were observed for all three domains-alerting, orienting and conflict-and revealed hyper- as well as hypoactivation in patients. Affected regions during alerting comprised a broad fronto-temporo-parieto-occipito-cerebellar network, while differences during orienting mainly tapped fronto-parietal regions and during conflict processing a thalamo-frontal-temporal occipital network including the postcentral regions. In general, hyperactivations were positively correlated with more severe psychopathologial symptoms.     

Heritability of Trail Making Test performance in multiplex schizophrenia families: implications for the search for an endophenotype

The impairment of the Trail Making Test (TMT) performance as a measure of executive function deficits has been found both in patients with schizophrenia and in their unaffected first-degree relatives, suggesting that it might be considered as a familial vulnerability marker, but its heritability estimates are not well known. This study investigated the genetic heritability of impairments in TMT performance using a sample of 80 schizophrenia patients, 145 unaffected first-degree relatives and 127 healthy controls from families with multiple members with schizophrenia. Consistent with previous reports in the literature, relatives performed in between healthy controls and schizophrenia patients. Based on these results, a variance component-analysis provided small, but significant additive heritability estimates for performance indices relating performance in TMT-version A to TMT-version B. These results showed that this significant but small evidence of heritability on the one hand suggests an association with genetic predisposition to schizophrenia, but that TMT performance is also associated with epigenetic or environmental factors.     

Selective attention deficits reflect increased genetic vulnerability to schizophrenia

BACKGROUND: Impairment in attention is prominent in schizophrenia and may be a valuable genetic indicator for vulnerability to this disease. AIMS: We set out to characterize the attention deficits that may be associated with genetic liability to schizophrenia. METHODS: We compared attention performance in 55 people with schizophrenia, 95 of their first-degree relatives, and 61 unrelated controls. We also segregated presumed obligate carriers of genetic risk (POCs, N=12) and compared their performance with that of controls. RESULTS: Although the relatives of people with schizophrenia did not significantly differ from the normal controls on the tasks of attention, their scores were significantly ordered such that patients>relatives>normal controls during tasks of sustained and selective attention as measured by the Jonckheere-Terpstra Test (p<.05). Additionally, POCs were significantly worse than normal controls during selective attention tasks such as the Stroop (p=.03) and Letter Cancellation Task (p=.04). CONCLUSIONS: Heterogeneity in the first-degree relatives may have diluted the attention deficits present in those who are at genetic risk for schizophrenia. On the other hand, our findings in the more homogeneous group of POCs suggest that selective attention may be an indicator of genetic liability for schizophrenia.     

Executive dysfunctions as potential markers of familial vulnerability to bipolar disorder and schizophrenia

Attentional and executive impairments have been found both in patients with schizophrenia and in their unaffected first-degree relatives, suggesting that they might be considered as familial vulnerability markers. Several studies have shown that the performance of bipolar patients does not significantly differ from that of schizophrenic patients, so that executive and attentional deficits might not be specific to schizophrenia. In the present study, we aimed to identify executive dysfunctions in schizophrenia and bipolar disorder that might be vulnerability trait markers specific to one or common to both of these diseases. We assessed cognitive performance of euthymic bipolar and schizophrenic patients, their unaffected first-degree relatives and a healthy control group, using neuropsychological tasks to test different components of executive function: the Verbal Fluency Test, the Stroop Word Colour Test, the Wisconsin Card Sorting Test and the Trail Making Test. The two groups of patients and their unaffected relatives demonstrated disproportionately increased slowness on the Stroop test in comparison to the normal healthy group. Patients with schizophrenia performed poorly on all the tests in comparison to the normal healthy subjects, while no other impairment was observed in the bipolar patients and in the relatives of schizophrenic and bipolar patients. Enhanced susceptibility to interference and reduced inhibition could be transnosographical markers for a shared familial vulnerability common to schizophrenia and bipolar disorders.     

Action blind: Disturbed self-other integration in schizophrenia

Recent research using individual task settings suggests that a major problem in schizophrenia is a dysfunctional theory of mind system leading to false mental state attributions. However, if a more low-level deficit to integrate own and other's actions (action blindness) is present in schizophrenia is still unknown. Using a Social Simon task, we tested if schizophrenia patients have a deficit in self-other integration. Further, we tested for a possible genetic bias of this dysfunction by studying clinically unaffected first-degree relatives of schizophrenia patients. While schizophrenia patients showed no Social Simon effect, we found a reliable Social Simon effect in healthy participants and first-degree relatives of schizophrenia patients. Joint task performance differed statistically between patients and healthy controls. We did not find any differences in the size of the Social Simon effects of relatives and healthy controls. The present findings suggest that schizophrenia patients have severe problems with self-other integration, which may lead to problems in social interactions. Since first-degree relatives of schizophrenia patients showed a reliable Social Simon effect, the evidence for a genetic bias of this social dysfunction in schizophrenia however is weak.     

Attentional deficits in patients with schizophrenia and in their non-psychotic first-degree relatives

The aim of this study was to investigate whether non-psychotic relatives of schizophrenic probands have deficits in sustained attention as measured by the Continuous Performance Test, Identical Pairs version (CPT-IP) and whether such deficits are associated with negative schizotypal personality disorders. The study subjects were 23 schizophrenic probands, 45 of their first-degree relatives and 36 normal controls. For each subject, attention was assessed during five conditions (2 standard, 2 slow, 1 easy) of visual stimuli (numbers and shapes). Schizotypy status was determined with the physical anhedonia and social anhedonia scales of Chapman et al. (Chapman, L.J., Chapman, J.P., Raulin, M.L., 1976. Scales for physical and social anhedonia. Journal of Abnormal Psychology 42, 374-382). The CPT-IP sensitive index d' in the standard shape condition was significantly lower in schizophrenics and in their relatives than in controls. For all d' values, the percentage of impaired first-degree relatives was at an intermediate level between patients and control individuals. Furthermore, the schizophrenic probands made more random errors in the standard and in the slow number conditions than the other two groups. None of the schizotypy measures correlated with the CPT-IP deficits. These results suggest that spatial sustained attention deficit may be a vulnerability marker for schizophrenia; however, this deficit and the negative dimension of schizotypal personality disorders may be distinct traits.     

Complications obstétricales dans la schizophrénie : étude comparative en population tunisienne

The neurodevelopmental hypothesis in schizophrenia argues that this disorder may be a result of abnormal brain development due to genetic risk and or to environmental injury such as those due to obstetric complications. Very few studies from emerging countries have been published concerning obstetric complications in schizophrenia. However, meteorological, demographic and health factors in most of these countries are different from those in Western countries, and studies in this field may bring more findings. Our objectives were to compare the frequency of obstetric complications in a group of schizophrenic patients compared to two other groups: a group of first-degree relatives and a healthy control group, and to search for the relationships between these complications and the epidemiological and clinical features of schizophrenic patients. The study is a retrospective case-controlled one: a schizophrenic patient group (N = 55, 43 males and 12 females, median age = 30 years) was compared to a group of non-affected first degree relatives (N = 40, 31 males and 9 females, median age = 29 years) and to healthy controls without familial psychiatric history (N = 38, 25 males and 13 females, median age = 29 years), all matched according to age and sex. Obstetric complications were collected at home from the biological mothers at the time of a visit using the McNeil-Sjostrom questionnaire. Schizophrenic patients were clinically assessed using the Positive and Negative Symptoms (PANSS), the General Assessment of Functioning (GAF) and the Clinical Global Impressions (CGI). Obstetric complications frequency was significantly higher in schizophrenic patients: 67,3 versus 20,0% in their non affected relatives and 28,9% in the healthy controls (P < 0,001). The mean total score of obstetric complications was significantly higher in the schizophrenic group: 1,52 ± 1,47 versus 0,8 ± 1,77 in the non affected relatives and 0,5 ± 0,97 in the healthy controls (P < 0,001). In the schizophrenic patients, obstetric complications were more frequent during delivery period (50,9%) and neonatal period (45,5 %). More particularly in pre-term births (21,8%), low birth weight and fetal distress (18,2%) and premature rupture of the membranes (16,4%). A statistical relationship was established between obstetric complications frequency, autumn-wintry birth season, low school level and negative symptoms in the PANSS. However, no significant correlation was found between obstetric complications frequency, family psychiatric history and age of onset of schizophrenia. Through an investigation involving mental recall, our results proved a higher frequency of obstetric complications in schizophrenic patients. Our results support the role of obstetric complications in the etio-pathology of schizophrenia, in interaction with other environmental or genetic factors. This association favors the neuro-developmental hypothesis in schizophrenia. Further studies assessing influence of weather, specific infectious agents, and demographic factors could also be relevant.     

The N1 auditory evoked potential component as an endophenotype for schizophrenia: high-density electrical mapping in clinically unaffected first-degree relatives,first-episode,and chronic schizophrenia patients

The N1 component of the auditory evoked potential (AEP) is a robust and easily recorded metric of auditory sensory-perceptual processing. In patients with schizophrenia, a diminution in the amplitude of this component is a near-ubiquitous finding. A pair of recent studies has also shown this N1 deficit in first-degree relatives of schizophrenia probands, suggesting that the deficit may be linked to the underlying genetic risk of the disease rather than to the disease state itself. However, in both these studies, a significant proportion of the relatives had other psychiatric conditions. As such, although the N1 deficit represents an intriguing candidate endophenotype for schizophrenia, it remains to be shown whether it is present in a group of clinically unaffected first-degree relatives. In addition to testing first-degree relatives, we also sought to replicate the N1 deficit in a group of first-episode patients and in a group of chronic schizophrenia probands. Subject groups consisted of 35 patients with schizophrenia, 30 unaffected first-degree relatives, 13 first-episode patients, and 22 healthy controls. Subjects sat in a dimly lit room and listened to a series of simple 1,000-Hz tones, indicating with a button press whenever they heard a deviant tone (1,500 Hz; 17% probability), while the AEP was recorded from 72 scalp electrodes. Both chronic and first-episode patients showed clear N1 amplitude decrements relative to healthy control subjects. Crucially, unaffected first-degree relatives also showed a clear N1 deficit. This study provides further support for the proposal that the auditory N1 deficit in schizophrenia is linked to the underlying genetic risk of developing this disorder. In light of recent studies, these results point to the N1 deficit as an endophenotypic marker for schizophrenia. The potential future utility of this metric as one element of a multivariate endophenotype is discussed.     

Executive attention deficits in schizophrenia: Putative mandatory and differential cognitive pathology domains in medicated schizophrenia patients

Executive attention (EA) is a core-construct of working memory (WM) capacity. EA performance is directly related to dorsolateral prefrontal cortex (DLPFC) activation, a neural mechanism that is dysfunctional in schizophrenia. We examined the differences in particular types of EA failure in schizophrenia patients and healthy controls. We evaluated executive attention in 60 medicated schizophrenia patients and 60 matched healthy individuals. We used a standard WM task, a verbal n-Back task, to measure executive attention (WM accuracy). Our standard-version WM task (control block, 10 min long) was designed to examine baseline executive attention function and was followed by one out of three different experimental blocks (revised n-Back tasks). Baseline executive attention performance was significantly related to psychosis severity and functional capacity in the psychiatric group. In both healthy and psychiatric groups, experimental-block conditions revealed that domain-general recall had a differential effect on WM scores, and was related to the patient's clinical condition. Only in the psychiatric group domain-specific recall impairments were mandatory, most severe, and independent of baseline WM scores. The results revealed the importance of domain-general recall WM scores in the evaluation of executive attention deficits in patients and controls. Disruption in domain-specific recall may represent a specifier of cognitive impairment in schizophrenia spectrum disorders.     

Antisaccade performance is related to genetic loading for schizophrenia

Disturbances of the oculomotor system are promising endophenotypes for schizophrenia. Increased error rates in the antisaccade task and prolonged antisaccade latencies have been found in patients with schizophrenia and their first degree relatives. We investigated oculomotor performance in 41 parents of schizophrenia patients and 22 controls with a prosaccade task and an antisaccade task. Parents were grouped into parents with a positive family history for schizophrenia (N = 9) and parents with a negative family history for schizophrenia (N = 32). An overlap-paradigm was applied; eye movements were recorded using infrared oculography. The combined group of parents made more antisaccade direction errors than controls (p = 0.005) and there was a linear increase in direction errors from controls via negative family history parents to positive family history parents (p = 0.008). Antisaccade latencies were prolonged in the combined parent group (p = 0.057) compared to controls and there was a linear increase in latency with genetic loading (p = 0.018). No group differences were found for prosaccade parameters. These results support the hypothesis that antisaccade impairment is associated with genetic loading for schizophrenia.