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Jaswinder Singh , C. R. Mukundan , B. S. Das , B. Y. T. Arya

Abstract

The present investigation aims at understanding the nature of early and late components of Contingent Negative Variation (CNV) in patients with cortical lesion. C. T. Scan was used for determining the site of lesions. 12 space occupying lesion (SOL) patients matched with equal number of normal controls were studied. CNV was recorded with the conventional paradigm in which first stimulus was a click followed by a flash after a preset interval of 3 secs; the inter-trial interval was 4 secs. Cz and Fz electrode sites with linked ear-lobe reference electrodes were used. On line analysis was carried out with the help of a signal analyser. Results are indicative of deficits in the amplitudes of CNV measures in the patient group with respect to early and late components. An attempt was made to examine the effect of the caudality of lesion on the CNV components. Patients with anterior SOL showed more impairment as compared to the patients with posterior SOL, with respect to the early and late component of CNV. Results are discussed in the light of frontal lobe functions.

Keywords

Slow Potentials, Expectancy Wave, Anticipation, Attentional Processes, Frontal Lobes

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C. R. Mukundan , G. N. Narayana Reddy , A. S. Hegde , Jayanthi Shankar , V. G. Kaliaperumal

Abstract

A prospective study of 42 patients with head trauma was conducted with the aim of determining the clinical recovery pattern and its relationship with the recovery of neuropsychological functions. Clinical evaluation was carried out at admission, fifteen days, one month, three months, and one year after the trauma. Neuropsychological assessment was made during the first month, third month, and at the one year follow up. Functions assessed were attentional processes, mental arithmetics, psychomotor functions, ideational fluency, visuospatial perception, and verbal and visual learning and memory functions. Results showed that maximum rate of clinical recovery was evident in the first month after the trauma, whereas neuropsychological deficits persisted. Significant recovery of ideational fluency, psychomotor functions, and verbal learning and memory functions occurred by the third month. Modality specific attentional deficits, impairment of visual learning and mental arithmetics were present in the third month assessment, and these deficits continued to persist even in the one year assessment. The findings are indicative of a discrepancy in the recovery rate of right and left hemisphere functions, with the right hemisphere functions showing slow or poor recovery.

Keywords

Head Trauma, Neuropsychological Deficits, Recovery, Right Hemisphere Functions

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Deepa Thakur , C. R. Mukundan

Abstract

Hemispheric lateralization was assessed in schizophrenics and manics using dichotic listening tasks. The sample consisted of 113 schizophrenics, 11 manics and 20 normals. Laterality indices were determined for each of the three groups. Schizophrenics had a significant left ear advantage and mancis had a significant right ear advantage. As expected, the normals had a significant right ear advantage. The left ear advantage seen in schizophrenics may be an indication of a left hemisphere dysfunction. No definite evidence of a lateralized hemispheric dysfunction emerged with respect to the manics.

Keywords

Dichotic Listening, Lateralized Hemispheric Dysfunction, Schizophrenia, Manic Psychosis

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P. Dwivedi , C. R. Mukundan

Abstract

An attempt was made to determine the cerebral loci of distractibility and impairment in visual search. Sample size consisted of eight right hemispheric lesion cases, nine left hemispheric lesion cases and nine healthy controls. A battery of auditory tasks and another task based on visuomotor scanning were used to assess distractibility and impairment in visual search. Results evidenced greater distractibility in right hemisphere lesion cases and provided some evidence for right cerebral dominance in visual search.

Keywords

Visual Attention, Distractibility, Lateralization

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Aaron Mohanty , B. S. Das , C. R. Mukundan , N. Jamuna

Abstract

Thirteen patients who were operated for aneurysmal subarachnoid haemorrhage (SAH) were prospectively studied (prospective study group) at regular intervals in the post-operative period for cognitive deficits by complex neuropsychological tests. They were compared with 13 aneurysmal SAH patients operated on an average 2 years earlier (retrospective study group), 11 patients of lumbart disc proplase (patient control group) and 15 subjects (normal control group). The prospective study group as compared to the patient control and normal group had significant impairment in all the cognitive functions at discharge, which however, showed a constant improvement and reached near normal levels at the end of one year study period. The patients of the retrospective study group still had residual cognitive deficits.

Keywords

Subarachnoid Haemorrhage, Cognition, Quality of Life, Outcome

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Aaron Mohanty , B. S. Das , N. Jamuna , C. R. Mukundan

Abstract

Thirteen patients who were operated for aneurysmal subarachnoid haemorrhage (SAH) were prospectively studied (prospective study group) at regular intervals in the post-operative period. Quality of life was assessed in term of adjustments in occupation, social life, home life and emotional changes. The results were compared with 13 patients operated for aneurysmal SAH on an average 2 years earlier (retrospective study group), 11 patients of lumbar disc proplase (patient control group). About 50% of the prospective group and 75% of the retrospective study group had returned to work 3 months after surgery and 20% of either of the groups had changed occupation due to illness. The patients of both the study group had relatively better social outcome. Emotional changes were seen to be present as a major complaint in the anterior communicating and posterior communicating artery aneurysm patients.

Keywords

Subarachnoid Haemorrhage, Cognition, Quality of Life, Outcome

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Chitra Andrade , C. R. Mukundan

Abstract

The aim of the study was to determine if any difference existed in cognitive processing between social drinkers and teetotallers. Twenty-six male social drinkers and equal number of male teetotallers were tested on a battery neuropsychological of tests comprising of Visual and Verbal Learning and Memory Functions, Digit-Symbol Substitution Test, Trail Making Test and Raven's Standard Progressive Matrices. The results indicate a significant disadvantage in the social drinkers compared to the teetotallers on some of the functions involving immediate memory, psychomotor performance and abstract reasoning. No significant association emerged between test scores and drinking variables except trends in regard to correlation between quality of alcohol consumed in the most recent past and test performances.

Keywords

Social Drinking, Teetotallers, Neuropsychological Tests, Information Processing

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Chitra Andrade , C. R. Mukundan

Abstract

The study aimed to determine if any neurophysiological evidence supporting cognitive changes exist in social drinkers. The sample comprised of 44 male social drinkers and 22 teetotallers matched for age and education. Details of drinking habits were elicited through interviews of the subjects. The experiments consisted of tests for late Auditory Evoked Potentials (AEP), Auditory P300 and Contingent Negative Variation (CNV). EEG was recorded from the Fz and Cz electrode sites of the 10-20 International electrode placement system. The two groups were compared on the mean amplitudes and latencies of P1-N1-P2 components of the AEP, the P300 and the early and late components of the CNV. Results showed that the two groups did not differ significantly on both the amplitude and latency measures of the various components, indicating that there is no electrophysiological evidence of change in cognitive processing or brain dysfunction in social drinkers.

Keywords

Social Drinking, Event Related Potentials, AEP, P 300, CNV

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Vandana Varma , C. R. Mukundan , D. Nagaraja

Abstract

The Contingent Negative Variation (CNV) is a slow DC shift seen over the scalp during states of anticipation. The present investigation is an attempt to study the differences in the CNV between patients with dementia and the normal controls. The sample consisted of 8 patients with dementia, of which 4 had cortical atrophy and 4 had subcortical atrophy and 8 age and gender-matched normal subjects. CNV and auditory evoked potentials (AEP) were recorded on a Biologic Topographic Mapping System. Results indicated that in normals a typical topographic distribution of early and late components of CNV show greater amplitudes in the anterior and central electrodes. Of the 8 dementia patients, 4 patients with subcortical atrophy and 2 with cortical atrophy showed only early component. All the patients showed the NI component and there was no significant difference in the latency compared with the normal controls. However, significant amplitude reduction was noticed in the patients.

Keywords

Dementia, Contingent Negative Variation, Auditory Evoked Potential

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Shobini L. Rao , C. R. Mukundan , N. Jamuna , B. S. Das , K. V. R. Shastry , T. Hegde , M. V. Reddy

Abstract

Post traumatic syndrome/Post concussion syndrome (PCS) is frequently present after head injury. Symptoms are often multiple and patients report different symptoms. Neuropsychological deficits are also not uniform in patients with PCS. This variability of presentation may signify different patterns of symptoms and deficits. We studied the patterns of association between symptoms and neuropsychological deficits through cluster analysis. Ward's method of hierarchical clustering was followed by K-means partitioning method. Five clusters grouped the neuropsychological deficits into core cognitive domains. The core cognitive domains were either at the elementary level of cognitive functioning or at a system level of cognitive functioning. Different symptoms were associated with different deficits in the elementary and system level cognitive domains. Disruption of neural networks arising out of head injury was hypothesized to be the basis for the association between the symptoms and the cognitive deficits.

Keywords

Cognition Disorders, Head Injuries, Memory Disorders, Neuropsychological Tests, Post Concussion Syndrome

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C. R. Mukundan ¹, C. Kamarajan ², P. Ajayan ³, B. N. Roopesh ⁴, M. Sharma ⁴

Affiliations
1 Institute of Behavioral Sciences, Gujarat Forensic Sciences University, Gandhinagar, IN
2 Henri Begleiter Neurodynamics Laboratory, Department of Psychiatry, SUNY Downstate Medical Center Brooklyn, New York, US
3 Kirby Forensic Psychiatric Center Wards Island Complex, New York, US
4 Department of Clinical Psychology, National Institute of Mental Health & Neuro Sciences, Bangalore, karnataka, IN

Abstract

The paper evaluates the event related potential (ERP) findings reported on the effects of hypnotic suggestions on recognition. Tie findings indicated that sensory registration indicated by Pl, Nl and P2 components was unaffected in hypnotic trance and suggestion. However, hypnotic suggestions could block the recognition of the infrequent tone in an oddball paradigm and the P300 amplitude significantly reduced. On the other hand, hypnotic suggestion could enhance the amplitude of the P300 when suggestion was given that the participant would hear loud tones, even though the intensity of the tone was half of that used in the earlier paradigm. Studies using hypnotic suggestions clearly indicate that the genesis and strength of the P300 potential can be influenced by hypnotic suggestions. The findings are examined in the paper to understand the neurocognitive processes involved in recognition of external reality and to explain how recognition involves experiential interpretations of the individual, which cannot be objectively shared by others. The findings strongly support how suggestions and the mindset thereby created influence the functioning of the brain. The extraordinary outcome is the dual phase processing between the brain and the mind resulting in the development of a cognitive capacity to create mental concepts larger than reality, and use them for interpreting reality.

Keywords

Hypnotic Suggestions, Sensory Registration, P300 ERP, Recognition, Engrams, Psychogenesis.

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Shilpa Jasubhai ¹, Ritu Sharma ², C. R. Mukundan ³

Affiliations
1 Consultant Clinical Psychologist Ahmedabad, Gujarat, IN
2 Department ofPsychology, School ofLiberal Studies, Pandit Deendayal Petroleum University Raisan, Gandhinagar, Gujarat, IN
3 Axxonet Brain Research Laboratory, Axxonet System Technology, Bangalore, Karnataka, IN

Abstract

Encoding strategies are significant in determining individual's emotional control and mapping personality traits. The purpose of the present study is to investing association between encoding strategies, personality and emotional factors. This study documents result of responses trom 50 students trom undergraduate and post graduate program using psychological tests namely Neo Five Factor Inventory-3 (NEO-FFI-3), Emotional Intelligence Scale, Verbal Encoding Test and Visual Memory Test. Extroversion and introversion. Self-control (SE) and managing emotions (ME), simultaneous or sequential processing style, verbal encoding and verbal memory were measured. Inferences are drawn on student's preferences to attend to external stimulations versus preference to introspect along with preference to simultaneous visual processing or sequential visual processing. The presence of self-control of emotional responses is an important factor that controls the occurrences of several responses, which possibly will contribute to understanding of conflicts and personality problems. Absence or reduction in sequential processing of signals in verbal and visual modes could weaken rational processing abilities and strengthen holistic processing of relevant and irrelevant issues, which could again pose decision making difficulties. Development of emotional control must occur during the developmental stages and social conditioning plays very important role in deciding the development of such self-control. Present research work can facilitate ground across several domains for further investigations and tries to highlight that there is an acute need to address these problems from neuroscience and social psychology point of view, especially when developments of such controls are minimally present within the social network.

Keywords

Encoding, Extroversion, Introversion, Self-Control, Visual and Auditory Memory.

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