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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

An electrophysiological analysis of maxilliped beating in the blue crab, Callinectes sapidus.

Charlton, Milton Peter. January 1971 (has links)
No description available.
102

Topograhic distribution of human brain electrical activity associated with schizophrenia

Ciorciari, Joseph, jciorciari@swin.edu.au January 1999 (has links)
A literature review of the schizophrenia brain electrophysiology was undertaken with specific emphasis placed on the topographical distribution of evoked potentials (EPs). The outcomes of this review suggests that schizophrenia brain electrophysiology, demonstrate some differences, but with a variability reflective of the symptom heterogeneity. The literature associated with the use of attentional tasks while recording EPs, tended to demonstrate some consistency. The methodological issues associated with the EEG and EP recordings may also account for this variability. An evoked potential technique, which has been demonstrated to be sensitive to the changes in cognitive processes associated with attention, is the Steady State Probe Topography (SSPT) technique. The SSPT is a combination of both the Steady State Visual Evoked Potential (SSVEP) and the Probe-ERP paradigm. This technique allows the SSVEP to be measured continuously, is relatively insensitive to artifact, and can display the topographic distribution of the SSVEP measures during the attentional task. The technique employs the use of a sixty-four channel EEG recording system. This consists of a multichannel electrode helmet; multichannel amplifier/filter, task presentation computer and a computer controlled data acquisition system. Software was also developed to analyse the recorded brain electrical activity to produce the SSVEP magnitude and phase versus time series for each electrode site. The topographic distribution of the SSVEP measures associated with specific events during attentional tasks could also be displayed. At the time of the pilot study, this technique had not been applied previously to the study of schizophrenia and therefore warranted further study. Two separate studies are reported; an investigative pilot study and a chronic group study. The pilot SSVEP and schizophrenia study was designed to examine the changes in the SSVEP and its topography, during the performance of a number of attentional or activation tasks to examine the possibility of hypofrontality. The tasks selected for the study were those previously used for the examination of hypofrontality with metabolic imaging techniques; the Continuous Performance Task (CPT) and the Wisconsin Card Sort (WCS). The SSVEP was elicited by a superimposed 13Hz flicker on the visual field, while subjects performed computerised versions of the neuropsychological tasks. Topographical maps of the SSVEP magnitude distribution were then interpolated and displayed as an animated sequence synchronised with particular events occurring during the tasks. In comparison to the male control group, male schizophrenic patients exhibited differences in the SSVEP topography for all tasks, possibly reflecting the deficits in behavioural indices. Overall, the findings indicated that the technique demonstrated some merit for further examination of frontal SSVEP topography in schizophrenia. In a larger study of twenty chronic schizophrenia patients, the frontal topographical distribution of the SSVEP was examined. The earlier pilot study finding of reduced frontal SSVEP amplitude was replicated. The issue of hypofrontality in schizophrenia was applied as a possible interpretation.
103

Reciprocal Interactions Between Monoamines as a Basis for the Antidepressant Response Potential

Chernoloz, Olga 19 March 2012 (has links)
Despite substantial progress in the area of depression research, the current treatments for Major Depressive Disorder (MDD) remain suboptimal. Therefore, various medications are often used as augmenting agents in pharmacotherapy of treatment-resistant MDD. Despite the relative clinical success, little is known about the precise mechanisms of their antidepressant action. The present work was focused on describing the effects of three drugs with distinctive pharmacological properties (pramipexole, aripiprazole, and quetiapine) on function of the monoaminergic systems involved in the pathophysiology and treatment of MDD. Reciprocal interactions between the monoamines serotonin, norepinephrine, and dopamine systems allow the drugs targeting one neuronal entity to modify the function of the other two chemospecific entities. Electrophysiological experiments were carried out in anaesthetized rats after 2 and 14 days of drug administration to determine their immediate and the clinically-relevant long-term effects upon monoaminergic systems. Pramipexole is a selective D2-like agonist with no affinity for any other types of receptors. It is currently approved for use in Parkinson’s disorder and the restless leg syndrome. Long-term pramipexole administration resulted in a net increase in function of both dopamine and serotonin systems. Aripiprazole is a unique antipsychotic medication. Unlike all other representatives of this pharmacological class that antagonize D2 receptor, this drug acts as a partial agonist at this site. Chronic administration of aripiprazole elevated the discharge rate of the serotonin neurons, presumably increasing the overall serotonergic neurotransmission. Like aripiprazole, quetiapine is one of three atypical antypsicotic drugs approved for use in MDD. Prolonged administration of quetiapine led to a significant increase in both noradrenergic and serotonergic neurotransmission. Importantly, the clinically counter-productive decrease in the spontaneous firing of catecholaminergic neurons, induced by SSRIs, was overturned by the concomitant administration of both aripiprazole and quetiapine. The increase in serotonergic neurotransmission was a consistent finding between all three drugs studied herein. In every case this enhancement was attained in a distinctive manner. Understanding of the precise mechanisms leading to the amplification/normalization of function of monoamines enables potential construction of optimal treatment strategies thereby allowing clinicians greater pharmacological flexibility in the management of depressive symptoms.
104

An analysis of galvanic skin response measurements correlated with student participation in the electronic response programs of a general education biology course

Ketcham, Beverly Lynn, 03 June 2011 (has links)
Educators frequently neglect efforts to evaluate the affective components of instructional programs even though most agree that the affective domain is as important, or even more important, than the cognitive domain in learning. Measurement of cognitive attainment is easily accomplished, however, measurement of students' feelings, attitudes, concerns and values is difficult to accomplish.The purpose of the present research was to measure galvanic skin response (GSR) reactions of students to multi-media programs which were created to effect attitude change toward biological concepts in nonscience majors, and to thereby identify learning strategies or combinations of strategies that produce emotional and physiological reactions.The electronic response (ER) system of the Department of Biology at Ball State University was utilized in conducting the study. The effectiveness of producing emotional arousal by the strategies involved in nine ER programs was sampled by using the galvanic skin response (GSR) to measure the change in electrical skin conductance. The population tested for each ER program consisted of 30 subjects. An approximately equal number of males and females and an approximately equal number of morning, mid-day and afternoon sessions were sampled.In the treatment of data, the maximum GSR resistance, following specific ER program events, was calculated using a latency of approximately three seconds. Resistance per unit area of electrode plate surface was calculated in ohms/mm2 and converted to conductance (mhos/mm2). To establish a basis for comparing the emotional and attitudinal impact of each electronic response program, the maximum conductance for each event and information components of each event sequence was averaged for the 30 subjects.A dependent t-test for paired observations was utilized to determine the significant conductance change of corresponding components of the initial and final event sequences in each ER program. In those situations which were significant at the .05 probability level, farther comparisons were made between corresponding components of the initial and middle and middle and final event sequences. The t-test was also utilized to determine the significance of mean changes in conductance between selected information and question and question and answer slides within event sequences which produced a greater or lower conductance than previous event sequences, and those in which little variance or observable differences among components occurred.The principal conclusion drawn from the study is that the electronic response programs provide an effective mechanism for increasing emotional arousal, increasing involvement, and creating attitude change. All of the nine electronic response programs produced a gradual rise in average conductance from the beginning to the end of each program.Extremes in GSR reactions occurred in response to different types and combinations of narrative, pictorial presentations and musicalselections. Situations which created a mood or conveyed a feeling, possessed emotionally toned narrative or slides, or required a value stance or judgment produced the greatest GSR reactions. Calming, quiet, and relaxing music, unmoving slides, unemotional narration, questions lacking challenge or treating non-controversial subject matter, produced the smallest GSR reactions.The present study supports the contention that multiple stimuli, which increase the number of senses incorporated in the learning process and the interaction (response-reinforcement) of the learner, produce a greater emotional reaction than stimuli in one sense modality.The author considers that emotional responses involved and related with affective learning are as important, or more important, than cognitive attainment. Further investigations of the relationship between multimedia components and emotional arousal need to be carried out to ascertain the appropriate blending or combinations of stimuli which provide the best or most effective learning situations. Data obtained through research in the cognitive and affective aspects of instructional designs should also be correlated to determine how the most effective learning strategies can be developed.
105

Reciprocal Interactions Between Monoamines as a Basis for the Antidepressant Response Potential

Chernoloz, Olga 19 March 2012 (has links)
Despite substantial progress in the area of depression research, the current treatments for Major Depressive Disorder (MDD) remain suboptimal. Therefore, various medications are often used as augmenting agents in pharmacotherapy of treatment-resistant MDD. Despite the relative clinical success, little is known about the precise mechanisms of their antidepressant action. The present work was focused on describing the effects of three drugs with distinctive pharmacological properties (pramipexole, aripiprazole, and quetiapine) on function of the monoaminergic systems involved in the pathophysiology and treatment of MDD. Reciprocal interactions between the monoamines serotonin, norepinephrine, and dopamine systems allow the drugs targeting one neuronal entity to modify the function of the other two chemospecific entities. Electrophysiological experiments were carried out in anaesthetized rats after 2 and 14 days of drug administration to determine their immediate and the clinically-relevant long-term effects upon monoaminergic systems. Pramipexole is a selective D2-like agonist with no affinity for any other types of receptors. It is currently approved for use in Parkinson’s disorder and the restless leg syndrome. Long-term pramipexole administration resulted in a net increase in function of both dopamine and serotonin systems. Aripiprazole is a unique antipsychotic medication. Unlike all other representatives of this pharmacological class that antagonize D2 receptor, this drug acts as a partial agonist at this site. Chronic administration of aripiprazole elevated the discharge rate of the serotonin neurons, presumably increasing the overall serotonergic neurotransmission. Like aripiprazole, quetiapine is one of three atypical antypsicotic drugs approved for use in MDD. Prolonged administration of quetiapine led to a significant increase in both noradrenergic and serotonergic neurotransmission. Importantly, the clinically counter-productive decrease in the spontaneous firing of catecholaminergic neurons, induced by SSRIs, was overturned by the concomitant administration of both aripiprazole and quetiapine. The increase in serotonergic neurotransmission was a consistent finding between all three drugs studied herein. In every case this enhancement was attained in a distinctive manner. Understanding of the precise mechanisms leading to the amplification/normalization of function of monoamines enables potential construction of optimal treatment strategies thereby allowing clinicians greater pharmacological flexibility in the management of depressive symptoms.
106

Attentional workload and the ERPS negative difference (ND) and mismatch negativity (MMN) /

Singhal, Anthony. January 1998 (has links)
Thesis (M.A.)--York University, 1998. Graduate Programme in Kinesiology and Health Science. / Typescript. Includes bibliographical references (leaves 52-59). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ39233.
107

An electrophysiological study on the sacculo-oculo-motor relation in cats.

Poon, Wai-fung, Paul. January 1974 (has links)
Thesis--M. Phil., University of Hong Kong. / Mimeographed.
108

Fast signal processing techniques for surface somatosensory evoked potentials measurement

Lam, Shing-chun, Benny., 林成俊. January 2003 (has links)
published_or_final_version / abstract / toc / Orthopaedics and Traumatology / Master / Master of Philosophy
109

MOVEMENT-RELATED CEREBRAL POTENTIALS AND THEIR ASSOCIATION WITH MOVEMENT TERMINATION

Wilke, John Thomas January 1973 (has links)
No description available.
110

Changes in brain oxygen tension evoked by sensory stimulation.

Gijsbers, Karel J. January 1966 (has links)
The use of physiological concepts in psychological theory has led to attempts by psychologists and physiologists to establish neurophysiological correlates of behaviour (Hebb, 1955; John & Killam, 1959). While studies of the effects of lesions and electrical or chemical stimulation of cerebral tissue have provided useful insights into the physiological basis of behaviour, attempts to observe the ongoing activity of the central nervous system in an awake, behaving organism have encountered serious problems. [...]

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