Human visual evoked responses are related to heart rate.

The purpose of the present experiment was to determine the relation between changes in heart rate and averaged evoked potentials. Sixteen male subjects with variable heart rates received 50 flashes of light during fast heart beats, 50 during slow heart beats, and 50 during midrange heart rate level. Evoked responses were recorded from the scalp overlying the right and left occipital lobes. Heart rate, respiration, eye movements, and cephalic blood flow were also recorded. The results indicated that spontaneous changes in heart rate are related to changes in visual evoked responses and that this relation differs for the two cerebral hemispheres. Furthermore, cephalic pulse amplitude was largest following slow heart beats and smallest following fast heart beats, which suggests that changes in heart rate are related to changes in cerebrovascular as well as electrocortical activity. The results are discussed in terms of formulations derived from behavioral studies regarding the relation between cardiovascular activity and attentional processes.     

Effects of learned helplessness training on instrumental heart rate control in humans

In Experiment 1, subjects who received feedback contingent on short interbeat intervals (relative to a baseline period) learned to accelerate their heart rates, but subjects who received noncontingent feedback did not. In Experiment 2, subjects who were exposed to noncontingent aversive noises later showed significant performance deficits on both an instrumental and a cognitive task. Attributional style predicted helplessness deficits on the cognitive but not the instrumental task. Experiment 3 demonstrated that experimentally induced helplessness interferes with biofeedback learning. Attributional style did not predict the occurrence of helplessness deficits in this context. Results are discussed in terms of the nature of biofeedback training and the range of behaviors that learned helplessness training affects.     

Cognitive reappraisal increases heart rate variability in response to an anger provocation

Adaptive self-regulatory responses to negative events are associated with good mental health, social functioning, and physical health. Two forms of emotion regulation that have received attention within the context of anger are cognitive reappraisal and expressive suppression. Research suggests that greater heart rate variability (HRV) is a physiological indicator of adaptive emotion regulation and decreased mental load. In the present experiment, we recorded HRV while 131 undergraduate women viewed an anger-inducing video of a fellow student arguing for a position counter to that of the participant on an important political issue. Immediately prior to viewing, participants were instructed to reappraise, suppress their emotions, or simply watch the video as normal. Participants in the reappraisal condition showed increased HRV whereas those in the suppression and control condition showed no such increase. These results provide support for increased HRV as a biological correlate of adaptive emotion regulation. One implication is that cognitive reappraisal might afford greater autonomic flexibility when an individual is confronted with anger-inducing events.     

Awareness of the response after feedback training for changes in heart rate and sudomotor laterality

What is the relation between the ability to control visceral responding on a biofeedback task and the ability to report behaviors actually contributing to this performance? Subjects received biofeedback training for unidentified visceral responses and then gave written reports about what they had done to control the feedback displays. Independent judges were given these reports and, on the basis of knowledge about activities known to contribute to visceral activity, were asked to determine the visceral responses for which the subjects had been trained. The reports of subjects who succeeded at bidirectional control of heart rate (Experiment 1) or sudomotor laterality (Experiment 2) showed awareness of behaviors related to feedback as assessed by this procedure, whereas the reports of subjects who failed at bidirectional control did not. Subsequent experiments indicated that these results did not depend on a learning strategy that might have been specific to the initial studies. These findings call into question the view that people are unaware of what they have done to produce the response after training on biofeedback tasks. Earlier studies reporting lack of awareness in biofeedback are discussed in light of factors that affect the measurement of biofeedback learning and response awareness.     

Development of physiological response patterns concomitant with the learning of voluntary heart rate control.

Thirty-six male undergraduate students were instructed to raise or lower heart rate in a multiple-session biofeedback experiment. Systolic and diastolic blood pressure, frontalis electromyographic activity, and skin conductance level were simultaneously recorded throughout biofeedback training. Principal axes factor analyses showed that physiological response patterning concomitant with the development of heart rate control was different early in training (Training Session 1) than it was late in training (Training Session 4) for both speeding and slowing conditions. These results indicate that different heart rate control strategies were used by the subjects early and late in training. The factor patterns also indicated a tendency for greater heart rate response specificity as training progressed for both speeding and slowing. Heart rate speeding sessions were also found to be associated with a significant increase in perceived state anxiety as measured by the State-Trait Anxiety Inventory. No significant change in perceived anxiety state, however, was associated with heart rate slowing.     

Wisconsin Card Sorting in adolescents: analysis of performance, response times and heart rate

Forty-nine adolescents performed the Wisconsin Card Sorting Test (WCST). A main PCA component of WCST performance was identified as 'efficiency of reasoning'. This factor was related to feedback processing. From the WCST, a perseveration score can be derived. Perseveration is the continued application of a rule, after it has been disconfirmed. We compared more and less perseverating subjects in relation to stimulus-response (SR) time, feedback inspection time and cardiac acceleration and deceleration. Less perseverating subjects responded faster, and had longer and more adaptive inspection times of error feedback. We examined the switch from rule application to rule search, and the difference between correct and error responses. A transient cardiac deceleration at the initiation of rule search was interpreted as a change in supervisory attention. An error-related deceleration to negative feedback was interpreted as a disturbance of higher control processing. Previous trial feedback influenced current processing time, feedback inspection time, and the cardiac acceleration and deceleration responses.     

Changes in the general activation level in psychophysiologic studies--II. Values of auditory evoked potentials in relation to impression and perception and heart rate

In psychophysiology all procedures used are accompanied with changes of general activation level (GAL) of the subjects. In our study these changes are characterized by self-assessment of the internal state and by the mean heart rate (HR) of each period. On the basis of these data group mean auditory evoked potentials (AEPs) were computed. The influence of the GAL on the N 110- and P 190-amplitudes of the AEPs was analysed. There was no effect on the P 190-amplitude whereas the N 110-amplitude shows distinct responses on changes in GAL. These amplitudes diminished when the subjects reported a change of internal state. The diminishing of N 110-amplitudes took place as well at an increase as at a decrease of the internal state factors. Comparing the HR and the N 110 of the AEPs we found an inverse U-shaped dependence. These results are discussed in comparison to the literature. Furthermore a model which could elucidate the observed findings is presented for a critical discussion.     

Spatial summation in the evoked cortical response to auditory stimuli

Six Ss were presented monaurally and binaurally with stimuli of 0.5, 2.0, and 4.0 kHz at 40 and 70 dB sensation levels. Their computer averaged evoked potentials indicated substantially larger amplitudes (N₁ -P₂) with bilateral stimulation, regardless of frequency. Stimulation at 70 dB SL gave greater responses than that to 40 dB.     

Neurochemical aspects of the sexual response cycle

What drives the human sexual response cycle? The human sexual response cycle is a highly complex phenomenon that encompasses many transmitters and transmitter systems centrally and peripherally. The endocrine system is also intricately involved in the brain and in the periphery organs. Integration of these systems is a function of the nervous system that ultimately produces a vast array of cognitive, emotional, physiological, and behavioral responses. Therefore, it is not surprising that a disturbance in even a single system will lead to dysfunction in one or more phases of the sexual response cycle. This article highlights the complex roles the aminergic system plays along with key hormones that are equally involved. The article also points out how rudimentary and fragmented our knowledge is in this field and how few controlled studies are available. The potential for development of specific agents that target selective sexual dysfunctions is exemplified in sildenafil, the first such agent ever to be brought to market.     

A comparison of chinchilla auditory evoked response and behavioral response thresholds

The auditory sensitivity of the chinchilla was measured by both a behavioral and auditory evoked-response (AER) procedure. There was no significant difference in either the waveform or the threshold of the AER recorded over the tentorium from awake and anesthetized chinchillas. The chinchilla threshold for pure tones appears to be more sensitive when measured by the behavioral technique than by the AER method. Both the AER and behavioral response of three chinchillas exposed to a 105 dB SPL octave band of noise centered at 2 KHz for 3 h shifted markedly after the exposure. However, the difference between the AER and behavioral response threshold was reduced or absent. During the process of recovery the difference between the two responses begins to reappear.     

Infant temperament and the brainstem auditory evoked response in later childhood.

Brainstem auditory evoked responses (BAERs) were evaluated on 10-12-year-old children (N = 56) who had been classified as high or low reactive to unfamiliar stimuli at 4 months of age. BAER measurement was selected because high reactive infants tend to become inhibited or fearful young children, and adult introverts have a faster latency to wave V of the BAER than do extroverts. Children previously classified as high reactive at 4 months had larger wave V components than did low reactive children, a finding that possibly suggests greater excitability in projections to the inferior colliculus. The fact that a fundamental feature of brainstem activity differentiated preadolescent children belonging to two early temperamental groups supports the value of gathering physiological data in temperament research.     

Random fluctuations of response rate

A simple model for fluctuating interresponse times is developed and studied. It involves a mechanism that generates regularly spaced excitations, each of which can trigger off a response after a random delay. The excitations are not observable, but their periodicity is reflected in a regular patterning of responses. The probability distribution of the time between responses is derived and its properties are analyzed. Several limiting cases are also examined.This paper was completed while the writer was a visiting summer scientist at the Lincoln Laboratory, Lexington, Mass.     

Effect of lingual vibrotactile stimulation on the averaged cortical evoked response

This study was designed to determine the feasibility of using lingual vibrotactile stimulation to elicit an averaged evoked response and to investigate the effects of two supra-threshold intensity levels of lingual vibrotactile stimulation on the electro-cortical activity of the brain. The evoked responses were analyzed according to the amplitude of N1-P2 (in microvolts). Analysis indicates that the tongue can successfully be used as a stimulus site in the elicitation of an evoked response. The amplitudes of the evoked response elicited by 2 micrometers sensation level and 5 micrometers sensation level on the tongue are essentially the same. The relative difference between these levels is not sufficient to produce significant differences in the amplitudes of their respective evoked responses.     

The structure of response rate

Interresponse time distributions of the terminal rate under fixed-interval and fixed-ratio schedules were examined, using data from three rats in each case. By means of a sequential analysis, the overall interresponse time distributions were separated into orderly components. Consideration of the component distributions suggested that multiple determinants of rate act in succession, not simultaneously, and that probability of reinforcement has an important effect on the probability of occurrence of interresponse times.     

Decision making and the P300 component of the cortical evoked response

The amplitude of P300, and of other components of the evoked potentials, was examined during a task which required Ss to make a response appropriate to the conjoint properties of two rapidly successive visual patterns. In one set of conditions, the task was structured such that both stimuli were needed for the choice judgment. In another set of conditions, the task was changed from choice to simple RT by presenting the patterns in a predictable order. It was observed that P300 was enhanced during the choice RT conditions and that this enhancement was present only for the P300 following the stimulus permitting the choice and not the other, relevant but not decisive, stimulus appearing in close temporal proximity. An appreciable degree of independence between P300 and other components was indicated by the appearance of P300 under conditions in which other evoked potential components were entirely refractory. The data support an account for P300 in terms of poststimulus processes, such as decision making, and not in terms of preparatory adjustments.