Patterns of cortical activity in schizophrenia

1994 ◽  
Vol 24 (4) ◽  
pp. 947-955 ◽  
Author(s):  
J. Schroeder ◽  
M. S. Buchsbaum ◽  
B. V. Siegel ◽  
F. J. Geider ◽  
R. J. Haier ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Parietal Cortex ◽  
Hemispheric Asymmetry ◽  
Performance Test ◽  
Temporal Cortex ◽  
Continuous Performance Test ◽  
Healthy Controls ◽  
Positron Emission ◽  
Schizophrenic Patients ◽  
Schizophrenic Group

SynopsisEighty-three patients with schizophrenia and 47 healthy controls received positron emission tomography (PET) with 18F-2-deoxyglucose uptake while they were executing the Continuous Performance Test (CPT). The entire cortex was divided into 16 regions of interest in each hemisphere, four in each lobe of the brain, and data from corresponding right and left hemispheric regions were averaged. Data from the schizophrenic patients were subjected to a factor analysis, which revealed five factors that explained 80% of the common variance. According to their content, the factors were identified and labelled ‘parietal cortex and motor strip’, ‘associative areas’, ‘temporal cortex’, ‘hypofrontality’ (which included midfrontal and occipital areas) and ‘frontal cortex’. Hemispheric asymmetry was only confirmed for the temporal cortex. Factor weights obtained in the schizophrenic group were applied to the metabolic data of the healthy controls and factor scales computed. Schizophrenics were significantly more hypofrontal than the controls, with higher values on the ‘parietal cortex and motor strip’ factor and a trend towards higher values in the temporal cortex. A canonical discriminant analysis confirmed that the ‘hypofrontality’ and ‘parietal cortex and motor strip’ factors accurately separated the schizophrenic group from the healthy controls. Hemispheric asymmetry was only confirmed for the temporal lobe. Significantly higher factor scores for the left temporal lobe in schizophrenics than in normals were obtained when calculated for the right and left hemisphere separately. Taken together, our results confirm the importance of hypofrontality as a pattern of cortical metabolic rate and point to the potential importance of parietal and motor strip function in schizophrenia.

Feigned ADHD Associated Cognitive Impairment: Utility of Integrating an Eye-trAcker and the MOXO-dCPT

2021 ◽  
pp. 108705472110636
Author(s):  
Astar Lev ◽  
Tomer Elbaum ◽  
Corinne Berger ◽  
Yoram Braw
Keyword(s):  
Cognitive Impairment ◽  
Performance Test ◽  
Continuous Performance Test ◽  
Gaze Direction ◽  
Lower Sensitivity ◽  
Healthy Controls ◽  
Continuous Performance ◽  
Eye Tracker ◽  
Validity Indicators ◽  
Initial Exploration

Objective: The current study assessed the utility of eye-movements measures, gathered while participants performed a commercially available Continuous Performance Test (CPT), to detect feigned ADHD-associated cognitive impairment. Method: Healthy simulators ( n = 37), ADHD patients ( n = 33), and healthy controls ( n = 36) performed an eye-tracker integrated MOXO-dCPT and a stand-alone validity indicator. Results: Simulators gazed significantly longer at regions that were irrelevant for successful MOXO-dCPT performance compared to ADHD patients and healthy controls. This eye-movement measure, however, had lower sensitivity than traditional MOXO-dCPT indices. Discussion: Gaze direction measures, gathered while performing a CPT, show initial promise as validity indicators. Traditional CPT measures, however, are more sensitive and therefore offer a more promising path for the establishment of CPT-based validity indicators. The current study is an initial exploration of the issue and further evaluation of both theoretical and practical aspects is mandated.

Laterality of visuo-spatial attention in acute and chronic schizophrenia, major depression and in healthy controls

1995 ◽  
Vol 25 (5) ◽  
pp. 1091-1095 ◽  
Author(s):  
R. E. O'Carroll ◽  
A. Rogers ◽  
S. M. Lawrie ◽  
C. Murray ◽  
M. Van Beck ◽  
...  
Keyword(s):  
Major Depression ◽  
Spatial Attention ◽  
Chronic Schizophrenia ◽  
Healthy Controls ◽  
Opposite Pattern ◽  
Chronic Schizophrenic ◽  
Schizophrenic Patients ◽  
Schizophrenic Group ◽  
Two Measures

SYNOPSISPrevious studies have suggested that schizophrenia is characterized by an asymmetry of visuo-spatial attention, in particular that acute unmedicated schizophrenics demonstrate relative inattention to right hemispace, whereas chronically medicated patients demonstrate the opposite pattern. In the present study, 30 unmedicated schizophrenic patients, 32 chronically medicated schizophrenic patients, 30 patients suffering from major depression and 60 healthy controls were assessed using two measures of hemispatial attentional neglect, namely letter and star cancellation. The results demonstrated that the chronic schizophrenic group made more total omissions for star cancellation (in both right and left hemispace), but that there was no difference between the groups in terms of omission asymmetry for either letter or star cancellation.

scholarly journals Neurodevelopmental correlates in schizophrenia

2003 ◽  
Vol 131 (7-8) ◽  
pp. 294-299 ◽  
Author(s):  
Maja Ivkovic ◽  
Aleksandar Damjanovic ◽  
Vladimir Paunovic
Keyword(s):  
Developmental Disorders ◽  
Healthy Controls ◽  
Birth Complications ◽  
Maternal Recall ◽  
Structural Abnormalities ◽  
Schizophrenic Patients ◽  
Schizophrenic Group ◽  
Neuro Imaging ◽  
Minor Physical Anomalies

Contemporary aetiopathogenetic considerations, based on neuro-imaging genetic and developmental neurobiology studies, suggest neurodevelopmental origin of schizophrenia. Several lines of evidence including structural abnormalities on in vivo brain imaging, the excess of prenatal and obstetric complications and the association of congenital and minor physical anomalies with schizophrenia, strongly indicate the neurodevelopmental pathogenesis of schizophrenia. On the other hand, controversial concept of psychotic continuum suggests schizophrenia and depression sharing the same genetic contribution to the pathogenesis. If this would be the case, depression could also be considered as neuro developmental disorder. The aims of the study were to investigate the association between: a) pregnancy and birth complications (PBC), and b) minor physical anomalies (MPA) and schizophrenia or depression. Experimental groups consisted of 60 schizophrenic, 28 major depression patients and 30 healthy controls. All patients were diagnosed according to DSM-IV. Schizophrenic group was divided with regard to PANSS score into positive (n=32) and negative form (n=28) subgroups. PBC information were gathered from maternal recall while MPA were examined by using Waldrop scale for adults. The results showed that negative and positive schizophrenic subgroups had significantly more PBC than depressive group (p<0,05), as well than controls (p<0,001; p<0,05; respectively). There was no significant trend for more PBC in negative than in positive subgroup. All schizophrenic patients had higher rates of MPA than depressives (p<0,05). This trend for more MPA was not significant in comparison with healthy controls. These findings suggest that schizophrenia, especially its negative forms, could be considered as a member of the spectrum of neuro developmental disorders, which does not seem to be the case with depression. PBC and MPA could also be valuable in evaluation of risks for schizophrenia and possible predictive indicators of its development.

scholarly journals Strength of attention-sampling parietal EEG theta rhythm is linked to impaired inhibition in adult ADHD

2020 ◽  
Author(s):  
Benjamin Ultan Cowley ◽  
Kristiina Juurmaa ◽  
Jussi Palomäki
Keyword(s):  
Test Performance ◽  
Adult Adhd ◽  
Performance Test ◽  
Phase Locking ◽  
Continuous Performance Test ◽  
Adhd Group ◽  
Healthy Controls ◽  
Sensitivity Indices ◽  
Impaired Attention ◽  
Phase Locking Value

Attention-deficit hyperactivity disorder (ADHD) in adults is understudied, especially regarding neural mechanisms such as oscillatory control of attention sampling. We report an EEG study of such cortical oscillations, in ADHD-diagnosed adults taking a continuous performance test that measures the ability to sustain attention and inhibit impulsivity for a prolonged period of time.We recorded 53 adults (28f, 25m, aged 18-60), and 18 matched healthy controls, using 128-channel EEG. We analysed features with established links to neural correlates of attention: event-related (de)synchronisation (ERS/D), alpha and theta frequency band activation, phase-locking value (PLV), and timing-sensitivity indices; in frontal and parietal scalp regions.Test performance distinguished healthy controls from ADHD adults. The ADHD group manifested significantly less parietal pre-stimulus 8Hz theta ERS during correct inhibition trials, less frontal & parietal post-stimulus 4Hz theta ERS during inhibition & response trials, and increased frontal & parietal pre-stimulus alpha ERS during inhibition & response. They showed significantly reduced fronto-parietal connectivity that lagged across trials and was strongly lateralised. In addition, they had reduced sensitivity to targets in stimulus-locking measures.Building on the hypothesis of parietal attention sampling, our results suggest that ADHD adults have impaired attention sampling in relational categorisation tasks.

scholarly journals High Order Linguistic Features Such as Ambiguity Processing as Relevant Diagnostic Markers for Schizophrenia

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Daniel Ketteler ◽  
Anastasia Theodoridou ◽  
Simon Ketteler ◽  
Matthias Jäger
Keyword(s):  
High Order ◽  
Test Battery ◽  
Healthy Controls ◽  
Linguistic Features ◽  
Performance Deficits ◽  
Linguistic Performance ◽  
Order Language ◽  
Function Test ◽  
Schizophrenic Patients ◽  
Schizophrenic Group

Due to the deficits of schizophrenic patients regarding the understanding of vague meanings (D. Ketteler and S. Ketteler (2010)) we develop a special test battery called HOLF (high order linguistic function test), which should be able to detect subtle linguistic performance deficits in schizophrenic patients. HOLF was presented to 40 schizophrenic patients and controls, focussing on linguistic features such as ambiguity, synonymy, hypero-/hyponymy, antinomy, and adages. Using the HOLF test battery we found that schizophrenic patients showed significant difficulties in discriminating ambiguities, hypero- and hyponymy, or synonymy compared to healthy controls. Antonyms and adages showed less significant results in comparing both groups. The more difficult a linguistic task was, the more confusion was measured in the schizophrenic group while healthy controls did not show significant problems in processing high order language tasks.

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