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http://hdl.handle.net/11375/13045
Title: | Determinants of Voluntary Electrodermal and Cardiac Control |
Authors: | Lacroix, Michael John |
Advisor: | Roberts, L. E. |
Department: | Psychology |
Keywords: | Psychology;Psychology;Psychology |
Publication Date: | 1976 |
Abstract: | <p>The thesis was concerned with the general question of how voluntary control, defined as compliance with verbal instructions to change the response, is achieved over skin conductance and heart rate. This question encompasses three separate but related issues. First, what features of the experimental procedure contribute to the establishment of voluntary elecotrodermal and cardiac control? Second, what other response systems are affected when control is achieved over electrodermal and cardiac functions, and hnw are changes in these systems related to the occurrence of the target response? Finally, what is the process by which subjects learn to comply with an instruction to control skin conductance and heart rate, and is this process different for the two responses? The thesis bears on all three of these issues.</p> <p>Experiment 1 was designed to develop and test a procedure for producing voluntary control of skin conductance and heart rate. Ten subjects received either two days of training to control skin conductance followed by two days of training to control heart rate, or the converse. Subjects attempted to produce increases and decreases in the target response during discrete 30-second trials. They were given instructions to control sweating or heart rate, were provided with strategy suggestions likely to facilitate control, and also with auditary feedback whenever they produced changes exceeding a predetermined criterion. The results provided evidence of control over both skin conductance and heart rate.</p> <p>This control could have resulted from the instructions to control sweating and heart rate which were given to the subjects, from the strategy suggestions which were also provided, and/or from the exteroceptive feedback which was also provided. Experiment 2 examined the role of these variables in electrodermal and cardiac control. Sixty-four subjects were divided into eight groups. Four of these received three days of electrodermal training; the other four received three days of heart rate training. Two groups (one electrodermal and one cardiac) received only instructions to produce increases and decreases in the target response. Two others received strategy suggestions in addition to these instructions. Two more received instructions plus response-contingent feedback. Finally, the last two received instructions, strategy suggestions, and feedback.</p> <p>Instructions to control palmar sweating were insufficient to generate reliable bi-directional control of skin conductance. However, electrodermal control was established when feedback for skin conductance changes was also provided. On the other hand, providing subjects with strategy suggestions appeared to interfere with electrodermal control, when such control was evident in the first place. The results with respect to heart rate were somewhat different. Instructions to control heart rate were sufficient to generate reliable, bidirectional heart rate differences. Adding feedback to these instructions had little effect on performance. However, adding strategy suggestions clearly interfered with performance.</p> <p>Bi-directional differences in skin conductance were accompanied by differences in heart rate, body movement, respiration amplitude, and in a number of affective scales. However, these correlates did not appear to be intrinsically related to the skin conductance changes, and were probably due to the increase-decrease component of the instructions. Bi-directional differences in heart rate when heart rate was controlled were accompanied by differences in skin conductance, body movement, respiration frequency, respiration amplitude, and in several affective scales. Contrary to what was obtained with respect to skin conductance, however, there was evidence that the autonomic, somatomotor, and respiratory correlates of heart rate change were intrinsically involved in the performance of the heart rate response. It was suggested that the production of skln conductance changes was embedded in either the neural systems controlling specific hand movements or in those controlling a nonmotor arousal process. On the other hand, the production of heart rate changes was viewed as embedded in the neural systems controlling somatomotor and respiration functions.</p> <p>While the production of skin conductance and heart rate changes appeared to involve different processes, the acquisition of control over the two responses was viewed as involving the same basic process. That process was depicted as one in which feedback related to the occurrence of the larget response was utilized to identify response strategies which led to appropriate changes in target behaviour. It was suggested that changes in cardiovascular activity produced discriminable interoceptive afferentation that allowed subjects to identify effective response strategies without having to undergo training with exteroceptive feedback. On the other hand, it was suggested that afferentation arising as a consequence of electrodermal activity was less discriminable than that associated with cardiovascular function. Consequently, training with exteroceptive feedback was necessary in order to identify response strategies which led to appropriate changes in electrodermal responding.</p> |
URI: | http://hdl.handle.net/11375/13045 |
Identifier: | opendissertations/7878 8949 4262617 |
Appears in Collections: | Open Access Dissertations and Theses |
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fulltext.pdf | 84.39 MB | Adobe PDF | View/Open |
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