Sudeshna Das

Bio: Sudeshna Das is an academic researcher from Department of Health and Family Welfare. The author has contributed to research in topics: Vigilance (psychology) & Positive and Negative Syndrome Scale. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.

Does hallucination affect vigilance performance in schizophrenia? An exploratory study.

Abstract: The present study investigates the role of "auditory verbal hallucination" (AVH) in the attentional processes of individuals diagnosed with schizophrenia compared with healthy participants. The sample consisted of 26 participants diagnosed with schizophrenia divided into - "schizophrenia with hallucination" (N=12) and "schizophrenia without hallucination" (N=14). 13 matched healthy participants were taken. A general health questionnaire was used to screen out psychiatric morbidity in healthy participants. The presence and/or absence of AVH were substantiated through the administration of the Positive and Negative Syndrome Scale (PANSS). Only individuals having higher composite scores in the positive scale were included. Edinburgh Handedness Inventory was administered to all participants. Software designed to measure vigilance was used to assess attentional deficits in the three groups included in the study. The complexity of the "vigilance task" was varied across three parameters: (1) spatial position of the target stimulus and buffer, (2) frequency of the target stimulus and buffer and (3) colour of target stimulus and buffer. The performances of the 3 groups were compared statistically in terms of Hit, Miss and False Alarm scores. Results revealed that schizophrenia patients are deficient as compared to their healthy counterparts in the ability to focus on a specific target while inhibiting non-relevant information across all conditions. Also, schizophrenia patients who have AVH are relatively more deficient as compared to the schizophrenia patients without AVH. It can be concluded that perceptual abnormality in schizophrenia patients with hallucination has an additional negative impact on attentional processes.

Disturbances of selective attention in traumatic brain injury and schizophrenia: What is common and what is different?

Abstract: There are hypotheses that traumatic brain injury (TBI) and schizophrenia might exhibit similar patterns of cognitive disorders in attention, executive function and memory. Yet, empirical studies comparing directly the two populations are extremely rare. The aim of this exploratory study was to compare performance of patients with TBI and schizophrenia in a task of selective attention. A group of TBI patients ( n = 18), a group of patients with schizophrenia ( n = 21), and a control group with no history of neurologic or psychiatric illness ( n = 31) participated in this study. A paced paper-and-pencil cancellation task was completed by each participant, allowing for discrimination between intact and impaired attention subcomponents. Compared to the controls, both patient groups had (a) slower processing speed, (b) reduced target processing efficiency, (c) instant attentional overload, and (d) difficulties in discriminating targets from distractors. However, these deficits were of different degrees between the groups. Furthermore, (e) a marked selective impairment of processing of distractors was observed in patients with schizophrenia only, as well as (f) a failure to regulate attentional resources over time. Finally, (g) none of the groups showed any shifts in response strategies. These results suggest that there are large similarities in disturbances in selective attention between these two pathologies. Yet, whenever similar, these disturbances are of different degrees. Furthermore, there are some qualitative differences between the two pathologies.