Benha University

أنسام عبد السلام أحمدى

أستاذ مساعد

كلية الآداب علم النفس

الرسائل العلمية

3 الرسائل العلمية

Cognitive/Neural Compensatory Mechanisms in Schizophrenia: Reaction Times-Brain Activity Correlates

PhD
2021
المشرفون

Angus Macdonald

الملخص

Cognitive deficiency in schizophrenia (SZ) was found to be associated with decreased PFC activity compared to healthy controls (HC). Other studies referred to increased / intact patterns of PFC activity. Parallel to those inconsistent neuroimaging findings, schizophrenia patients also showed increased intra-individual reaction times variability (RT_IIV). In the current work, we suggested that inconsistent findings in schizophrenia neuroimaging literature are driven by their increased RT-IIV. We hypothesized that performance with increased reaction times in SZ patients reflects compensatory cognitive/neural mechanisms. To address that general hypothesis, we conducted three studies as follow: 1. Activation likelihood Estimation (ALE) meta analysis of (90 fMRI studies in SZ); In that study we were first concerned with extracting the most consistent neuroimaging findings in the previous SZ literature. Second, we conducted ALE analyses within two categories: experiment with impaired RT (effect sizes > 0.3) vs. experiments with unimpaired RT (effect sizes

الجامعة

university of minnesota

الدولة

USA

الرسالة كاملة ---

Spatial Attentional Control Is Not Impaired In Schizophrenia: Dissociating Specific Deficits From Generalized Impairments

PhD
2013
المشرفون

Angus Macdonald

الملخص

A large literature has established that people with schizophrenia are impaired on tasks that require attentional control. However, evidence is mixed as to whether these impairments are specific deficits (Oltmanns & Neale, 1975) or merely reflect a generalized impairment (Dickinson & Harvey, 2009). Recent evidence also suggests visual attentional control for encoding into working memory may be selectively spared in people with schizophrenia (Gold et al., 2006). The current study used a cued backward masking task to investigate 23 people with schizophrenia and 27 healthy controls. People with schizophrenia were hypothesized to perform better on invalidly cued trials when making a simple identification or location judgment. However, we found schizophrenia impaired performance on both valid and invalid cues to the same degree whether the cue was a stored representation (top-down) or presented at the location of the stimulus (bottom-up). In contrast to a large neuropsychological literature, these findings suggest that people with schizophrenia show no specific spatial attentional control deficit. The errors that they make on such task may be consistent with a generalized impairment.

الجامعة

university of minnesota

الدولة

USA

الرسالة كاملة ---

الفروق في المؤشرات النيوروسيكولوجية و الكيماوية العصبية بين مرضي الفصام و مرضي الوسواس القهري

MSc
2006
المشرفون

السيد ابو شعيشع ، عبد العزيز باتع

الجامعة

benha university

الدولة

egypt

الرسالة كاملة ---