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Biomedical subjects

P J Mikulka

Publications and source records attributed to P J Mikulka.

At least 19 recordsLinked to original sources
PubMed2000

Evaluation of a psychophysiologically controlled adaptive automation system, using performance on a tracking task.

Three experiments were conducted to evaluate the performance of a psychophysiologically controlled adaptive automation system. Subjects were asked to perform a compensatory tracking task while their electroencephalogram (EEG) was recorded and an engagement index was derived from the EEG, using the alpha, beta, and theta bandwidths: beta/(alpha + theta) and beta/theta. In Experiment I, EEG was recorded from three different sites: frontal, parietal, and temporal. Although tracking performance did not differ as a function of site, the number of task mode allocations was greater under a negative feedback contingency than under a positive feedback contingency. This effect was seen primarily from frontal sites. Experiments II and III evaluated the adaptive automation system, using extended runs under positive and negative feedback with either a slope (Experiment II) or absolute (Experiment III) criterion used to drive the system. Using either criterion, performance was found to be significantly better under negative feedback. Future evaluation and use of psychophysiologically controlled adaptive automation systems are discussed.

Adaptation, Physiological↗
PubMed2000

A closed-loop system for examining psychophysiological measures for adaptive task allocation.

A closed-loop system was evaluated for its efficacy in using psychophysiological indexes to moderate workload. Participants were asked to perform either 1 or 3 tasks from the Multiattribute Task Battery and complete the NASA Task Load Index after each trial. An electroencephalogram (EEG) was sampled continuously while they performed the tasks, and an EEG index (beta/alpha plus theta) was derived. The system made allocation decisions as a function of the level of operator engagement based on the value of the EEG index. The results of the study demonstrated that it was possible to moderate an operator's level of engagement through a closed-loop system driven by the operator's own EEG. In addition, the system had a significant impact on behavioral, subjective, and psychophysiological correlates of workload as task load increased. The theoretical and practical implications of these results for adaptive automation are discussed.

Adaptation, Psychological↗
PubMed1999

Evaluation of an adaptive automation system using three EEG indices with a visual tracking task.

A system was evaluated for use in adaptive automation using two experiments with electroencephalogram (EEG) indices based on the beta, alpha, and theta bandwidths. Subjects performed a compensatory tracking task while their EEG was recorded and converted to one of three engagement indices: beta/(alpha + theta), beta/alpha, or 1/alpha. In experiment one, the tracking task was switched between manual and automatic modes depending on whether the subject's engagement index was increasing or decreasing under a positive or negative feedback condition. Subjects were run for three consecutive 16-min trials. In experiment two, the task was switched depending on whether the absolute level of the engagement index for the subject was above or below baseline levels. It was hypothesized that negative feedback would produce more switches between manual and automatic modes, and that the beta/(alpha + theta) index would be most effective. The results confirmed these hypotheses. Tracking performance was better under negative feedback in both experiments; also, the use of absolute levels of engagement in experiment two resulted in better performance. There were no systematic changes in these effects over three 16-min trials. The implications for the use of such systems for adaptive automation are discussed.

Adaptation, Biological↗
PubMed1992

An alternative biofeedback-based behavior modification treatment for a case of chronic constipation.

A 31-year old female with chronic constipation was referred for treatment of a paradoxical contraction of the external anal sphincter (EAS) muscle during straining to defecate. The patient was dependent on laxative use and the digital removal of feces. The present program emphasized biofeedback training of the EAS utilizing the inexpensive, noninvasive procedure of disposable surface electrodes placed on the anal verge. Outcome of treatment resulted in an 89% decrease in laxatives used, complete termination of the digital removal of feces, and a notable decrease in EAS tension. The patient was able to maintain these gains at an 8 month follow-up.

Adult↗
PubMed1991

Transfer of training of the biofeedback-assisted control of hand temperature.

This study examined the effect of prior biofeedback-assisted training of hand warming or hand cooling on the subsequent ability to train the opposite response. A two-group crossover design employed 43 subjects with one group receiving three days of hand warming followed by three days of hand cooling, while the second group received the opposite sequence. Analysis indicated subjects were able to produce the appropriate changes in hand temperature and were more successful at hand cooling than hand warming. During the transfer of training phase, subjects with prior training in hand cooling were able to produce warming above baseline levels compared with subjects initially trained to hand warm. In contrast, prior training of hand warming had no effect on the subsequent ability to cool hands.

Adult↗
PubMed1990

Attitudinal body-image assessment: factor analysis of the Body-Self Relations Questionnaire.

This article presents an analysis of the factor structure of the Body-Self Relations Questionnaire (BSRQ), an attitudinal body-image instrument. Random stratified samples, drawn from a national survey, included 1,064 females and 988 males. In order to evaluate the replicability of the BSRQ factor structure, separate split-sample factor analyses (principal components with varimax rotation) were conducted for each sex. Largely consistent with the conceptual basis of the BSRQ, the resultant factors derived from each analysis were: Appearance Evaluation, Appearance Orientation, Fitness Evaluation, Fitness Orientation, Health Evaluation, Health Orientation, and Illness Orientation. Subsequent concordance analyses revealed marked stability of the factor structure both within and between sexes. Females demonstrated somewhat greater differentiation of body-image attitudes than did males. The utility of the BSRQ is discussed relative to extant body-image measures.

Adolescent↗
PubMed1989

Validity of Million's computerized interpretation system for the MCMI: comment on Moreland and Onstad.

Moreland and Onstad (1987) reported the results of a "controlled study" to determine the incremental validity of Million's computerized interpretive system for the Million Clinical Multiaxial Inventory (MCMI) in relation to the Barnum effect. Eight clinicians rated the accuracy of actual case reports and paired control reports that were randomly generated but designated experimental. However, in view of several limitations of their experimental design and statistical analyses, the authors may have prematurely concluded that the perceived accuracy of the interpretive system exceeds a Barnum base rate.

Diagnosis, Computer-Assisted↗
PubMed1984

The effect of amygdala-kindled seizures on the acquisition of taste and odor aversions.

Two experiments were conducted to investigate the effect of amygdala-kindled seizures on the acquisition of fluid aversions using taste, odor, and compound taste-odor cues. In Experiment 1 all subjects were poisoned with lithium chloride 30 minutes after ingesting a novel taste. Experimental subjects were either kindled 15 minutes following ingestion or 15 minutes following LiCl injection. The strength of the taste aversion in the kindled animals was significantly attenuated compared to nonkindled controls. There was a tendency for kindling within the CS-US interval to be more disruptive than kindling that occurred after LiCl injection. The second study explored the effect of kindling after the CS on the development of aversions to an odor cue or a compound taste-odor cue. This study found that kindling after drinking effectively blocked the acquisition of both odor and taste aversions and compounding did not affect the strength of the odor aversion.

Amygdala↗
PubMed1981

Multidimensionality of the Nowicki-Strickland locus of control scale for adults.

In order to investigate the dimensionality of the Adult Nowicki-Strickland Locus of Control Scale (ANS-IE), the responses of 120 undergraduate psychology majors were subjected to one principal components factor analysis using Kaiser's varimax criterion, Five meaningful factors emerged which accounted or 80.6% of the total variance. Results were discussed in terms of their similarity to other factor analyses using the children's version of this scale and to a factor analysis of the ANS-IE (chandler & Dugovics, 1977) which used a modified response format.

Journal Article↗
PubMed1977

Illness-alone exposure as a source of interference with the acquisition and retention of a taste aversion.

Four studies were conducted to explore the effects of unpaired lithium chloride (LiCl) injections, the unconditioned stimulus (US), on the acquisition and retention of a taste aversion. In Experiment 1, subjects were preexposed to a US; for one group the US was paired with a distinctive taste, whereas for a second group it was not. Following this preparation, both groups received the US paired with a novel taste. Only the US-alone group showed a retardation of subsequent taste-aversion conditioning. Experiment 2 indicated that an exposure to LiCl without a specific gustatory cue will interfere with the avoidance of a specific taste, regardless of whether the US experience occurs before or after a single taste-LiCl pairing. Following sucrose-LiCl pairings in Experiment 3A, LiCl-alone exposures retroactively interfered with the retention of the prior aversion to sucrose, with the level of post-US interference becoming an increasing function of the number of US-alone experiences. In Experiment 3B, the association of sucrose with LiCl did not interfere with the development of an almond aversion, whereas LiCl-alone exposures following the acquisition of a sucrose aversion proactively interfered with the development of a second taste aversion (almond). It is suggested that a physiological explanation will not adequately account for the present results of these experiments. The results are discussed within the framework of alternative associative models.

Animals↗
PubMed1977

Effect of whole-body vibration in combined axes and with noise on subjective evaluation of ride quality.

The effects on ratings of ride quality of discomfort produced by complex vibration and noise stimuli were investigated. The initial study examined effects of simultaneous vibration in the vertical and lateral axes in a simulated passenger aircraft. The second study examined the effects of simultaneously presented vertical vibration and noise stimuli. In both studies the components of complex stimuli were found to combine their effects at low levels of stimulation but to act separately at higher levels.

Adolescent↗