Sources of information which affect training and raising of heart rate

TIM3+ cells in gastric cancer: clinical correlates and association with immune context

BACKGROUND

T cell immunoglobulin and mucin domain-containing protein 3 (TIM3) is a crucial immune checkpoint and is considered as an emerging target for cancer treatment. However, the clinical significance and immune-related role of TIM3⁺ cells in gastric cancer remain unknown. This study aimed to investigate the clinical significance of tumour-infiltrating TIM3⁺ cells and their association with immune contexture in gastric cancer.

METHODS

This study enrolled three cohorts, including 436 tumour tissue microarray specimens and 58 fresh tumour tissues of gastric cancer patients from Zhongshan Hospital, and 330 transcriptional data from The Cancer Genome Atlas. TIM3⁺ cells and their association with CD8⁺ T cells were evaluated by immunohistochemistry and flow cytometry analyses. Kaplan-Meier curves, Cox model and interaction test were performed to assess clinical outcomes.

RESULTS

Tumour-infiltrating TIM3⁺ cells' high subgroups experienced poorer overall survival and disease-free survival and predicted inferior therapeutic responsiveness to fluorouracil-based adjuvant chemotherapy. TIM3 indicated CD8⁺ T cell dysfunction, which impeded chemotherapeutic responsiveness. Besides, HAVCR2 messenger RNA expression was associated with specific molecular characteristics.

CONCLUSIONS

The abundance of tumour-infiltrating TIM3⁺ cells could identify an immunoevasive subtype gastric cancer with CD8⁺ T cell dysfunction, suggesting that TIM3 might serve as a promising target for immunotherapy in gastric cancer.

Changes in heart rate during feedback control of respiration

Subjects received one of eight treatments: practice at increasing heart rate with heart-rate feedback, practice at decreasing heart rate with heart-rate feedback, practice at increasing heart rate without heart-rate feedback, practice at decreasing heart rate without heart-rate feedback, practice at increasing respiration rate with respiratory feedback, practice at decreasing respiration rate with respiratory feedback, practice at increasing respiration rate with respiratory instructions only, practice at decreasing respiration rate with respiratory instructions only. Heart rate, Respiration rate, and Respiration depth were measured. Analysis indicated that subjects who controlled respiration with respiratory feedback reliably increased and decreased heart rate; subjects who controlled respiration with respiratory instructions only reliably increased but not decreased heart rate; subjects in the respiratory-feedback conditions showed higher heart-rate increase and decrease than heart-rate increase and decrease of subjects in the other six conditions.

Heart rate discrimination and heart rate control: A test of Brener's theory

Three experiments were conducted to examine predictions from Brener's theory regarding the relationship between autonomic discrimination and autonomic control. Experiment 1 examined the possibility that training subjects to discriminate their heart rates would enhance their skill at controlling that response. Twenty subjects participated in two sessions during which one group of 10 subjects received training (knowledge of results) on the Ashton discrimination technique. The second group performed the discrimination task but received no training. All subjects then took part in a third session of heart rate (HR) control (both increase and decrease) where half of each of the aforementioned groups received feedback during the control task, while the other half performed the HR control task without feedback. Results indicated that for the control of both HR increases and decreases, there was no significant difference between those subjects trained to discriminate their HR, and those who had received no training to discriminate HR. The second experiment investigated the hypothesis that training subjects with feedback to control their HR would enhance their capacity to discriminate their heart activity. Ten subjects participated in two sessions of HR control during which half the subjects received feedback training to increase HR. During a third session, all subjects underwent a test of discrimination ability using the Ashton technique, and no knowledge of results regarding performance was provided. Results confirmed the hypothesis. The final experiment in the series investigated the discrimination/control relationship within a problem-solving framework and used 20 subjects. Results confirmed the hypothesis that subjects forewarned at the time of discrimination training that a heart rate control task was to follow would perform better than 10 subjects receiving no forewarning of the task objective. This effect took place independently of cardiac discrimination ability. A second finding from this experiment was that subjects trained to discriminate heart rate were better able to increase heart rate than untrained subjects. This result contradicts that of Experiment 1, and reasons for this anomaly are discussed in detail.

Heart rate decrease: a comparison of feedback modalities and biofeedback with other procedures

Sixty subjects were divided into six groups in a comparison of heart rate (HR) decreases obtained with (1) visual feedback, (2) auditory biofeedback, (3) combined visual and auditory biofeedback, (4) instructions to decrease HR without biofeedback, (5) sitting quietly, (6) abbreviated relaxation training, and, as a comparison, a group of 10 experienced mediators were also studied. Biofeedback stimuli were pulsed signals generated by the R-wave of the heartbeat. The results indicated that (a) there was no differential advantage on a HR decrease task to subjects receiving visual, auditory or combined biofeedback; and (b) all groups showed evidence of some decline in HR over the testing session. The mediation group showed the greatest overall decline.

Effects of health locus of control and health value upon EMG biofeedback training

Subjects who scored highly internal or external on a health locus of control scale and who scored high or low on the value each attached to good health were each given two sessions of frontalis EMG biofeedback training in accordance with a 2 x 2 x 2 factorial design. It was predicted that both internality and high health value would be positively associated with ability to control EMG and that these influences would combine additively. The predictions were not supported but a significant interaction between internality and health value was found. This interaction could be explained by assuming that both internality and high health value increased drive which in turn produced greater muscle tension, the relationship between drive and muscle tension being an ascending sigmoid function.

The role of biofeedback in the operant modification of human heart rate

The recent literature on the role played by biofeedback in the modification of human heart rate is reviewed. Emphasis is placed on research pertinent to the issue of whether biofeedback is more productively conceived as a reinforcer of an operant response or as a source of information enabling the development of a voluntary motor skill. Criticisms of the operant paradigm are answered, and limitations of the motor skills analogy are discussed. It is concluded that the operant conditioning paradigm best accounts for most available data on the role of biofeedback in heart rate control, and that it is superior to the motor skills model because it is more parsimonious and makes fewer untestable assumptions.

Information and reward in voluntary heart rate control

Two studies are reported which examined the relative effects of the pressence and absence of monetary incentives and instructions in a heart rate (HR) regulation task. Twelve male undergraduates were offered seven sessions of feedback assisted voluntary HR control training. In Experiment 1 six S s attempted to increase their HR with the aid of a "success," or positive binary visual signal. In Experiment 2 six S s were instructed to decrease their HR and were assisted by a "failure," or negative binary visual signal. In both studies the presence or absence of E's specific instructions to control HR was systematically varied from sessions 4 to 7. S s were paid on only half of the feedback trials of each session. These variables were thus systematically varied in a within-subject design. The main results suggest that (a) the instructions and monetary incentives significantly facilitated HR acceleration while showing no effects on HR deceleration; (b) in the no-instructions, no-incentive condition, HR control was minimal. The general hypothesis that Estes' interpretation of information and reward apply to human voluntary HR control received some support. It would appear that contrary to a traditional view, the exteroceptive feedback per se does not necessarily act as a reinforcer of the behavior, as witnessed for instance in the no-instructions, no-incentive conditions.

Voluntary heart rate lowering following a cardiovascular arousing task

The purpose of the research was to evaluate the effect of feedback-assisted voluntary control to lower heart rate (HR), following a non-somatic mediated task designed to induce cardiovascular activation. Twenty-seven male subjects participated in this study and were randomly divided into three groups. All subjects were submitted to an arousing mental arithmetic task for a 1 min period, followed either by a feedback-assisted HR lowering task (FG), by an unassisted HR lowering task (ICG), or by a relaxation period (RCG). During this period (2 min duration), ICG and RCG subjects were required, as a help for HR deceleration or relaxation, to track visually a sweeping line similar in form to the continuous analogue feedback of the FG subjects. This sequence, interspaced by a 1 min rest period, was repeated 10 times. Results showed that the mental arithmetic task was effective in producing consistent and repetitive HR acceleration. All three groups showed significative HR lowering during the following voluntary HR control or relaxation period. However, there was no difference in the speed or depth of HR lowering. It appeared that continuous-analogue feedback was not more effective than instructions to relax to assist HR return to lower levels.

Partial reinforcement in human biofeedback learning

This paper reviews the evidence for the efficacy of partial reinforcement in producing resistance to extinction in human biofeedback experiments. The methodological criteria necessary to demonstrate such effects are discussed, as is the status of the analogy of reinforcement and information feedback. It is suggested that the problem of maintaining responding in the absence of feedback should be tackled empirically rather than assuming the validity of findings from other areas of learning theory.

A comparison of the mechanisms and some properties of instructed sudomotor and cardiac control

Instructed control defined as differential compliance with verbal instructions to increase and decrease a response was assessed when a change in sudomotor activation or heart rate was specified as the behavioral goal. Instructed control of heart rate was evident prior to explicit feedback training for this response, but instructed control of sudomotor activation defined as finger sweating and measured as skin conductance was not. Feedback training subsequently established instructed control of sudomotor responding, but such training did not lead to a significant improvement in control of heart rate. Explicit strategy suggestions emphasizing emotional responding and intended or actual movement appeared to interfere with the performance of instructed control under both target conditions. Instructed changes in heart rate were attended by correlated changes in somatomotor and respiratory function. Somatomotor and respiratory responses were also observed when subjects were instructed to change sudomotor activation, but these correlated activities were of small magnitude and were not augmented by feedback training as was target responding. Several accounts of the basis for differences that were evident between the target conditions with respect to feedback effects and response patterns are discussed.

Effect of demand characteristics on heart rate during a behavioral avoidance test

A 2 X 2 experimental design utilized two levels of verbally reported snake fearfulness (high-low) and two levels of experimental demand (high-low) with 16 college student subjects during a behavioral avoidance test. Subjects given high-demand instructions for heart-rate increase increased their heart rate more than subjects given low-demand instructions. Results were specific to heart rate, as demand produced no effects on approach behaviors or fear ratings. Heart rate during the behavioral avoidance test was shown to be as susceptible to experimental demand as other studies have shown approach behaviors to be influenced.

The voluntary control of heart rate under differential somatic restraint

The purpose of this investigation was to test the hypothesis that subjects (Ss) can exert voluntary, bidirectional heart rate (HR) control in the absence of concomitant changes in respiration rate (RR) and muscle activity (chin EMG). Feedback-assisted HR control was studied under four experimental conditions involving increasing levels of somatic restraint: (a) No somatic controls, (b) RR pacing, (c) EMG feedback, to maintain constant muscle activity, and (d) RR pacing plus EMG feedback. Fifteen Ss, eight females and seven males, were assigned to each of these four conditions (N = 60). The HR control task involved ten increase and ten decrease trials in random order, each lasting 60 sec and preceded by a 60-sec resting baseline period. The results indicated that Ss produced significant HR increases (Xdelta = +3.4 bpm), but were unable to effect decreases (Xdelta = -.3 bpm). Furthermore, the magnitude of the obtained HR changes did not differ by experimental condition, i.e., by level of somatic restraint. While concomitant bidirectional RR changes were found, the pacing procedure effectively reduced, and on HR increase trials, nearly eliminated, RR involvement. No increases in EMG activity were found on HR increase trials for any of the four experimental conditions, whereas all groups showed some EMG decreases on HR deceleration trials. With respect to the question of somatic mediation of autonomic control, it is concluded that HR increases produced under paced respiration "favor" an interpretation of unmediated HR acceleration.

Criterion level and instructional effects in the voluntary control of heart rate

Two experiments are reported. In experiment 1 the effects of different punishment criteria on the acquisition of voluntary control of heart rate was studied in three groups of 10 subjects. Punishment criterion was manipulated so that the 10, 30 and 50% most extreme interbeat intervals in the opposite direction from the desired heart rate change were punished. Subjects received four training sessions, two directed at increasing heart rate, and two at decreasing. Substantial bidirectional heart rate changes were obtained very early in training. Some weak evidence of criterion effects was obtained. In a supplementary experiment modelled on experiment 1, the instructions plus feedback used in experiment 1 were compared with instructions alone. Feedback did not aid heart rate control. In both experiments there was evidence of skeletal involvement in the heart rate change.

Visceral responses to opposite types of autogenic-training imagery

The purpose of this experiment was to test whether suggestions of imagery of the type used in autogenic training have specific effects on autonomic responses. In order to control for the effort involved in imagery and to determine the specificity of the effect, opposite types of imagery were used: (a) hands warm and heavy, and (b) hands cool and light. Nine subjects were trained for six daily sessions. Within each day 16 stimulus presentations were made, equally balanced between the two types of imagery. Heart rate, respiration rate, and EEG in the alpha frequency were recorded throughout all sessions. The 'cool' instruction reliably increased heart rate and respiration above pre-stimulus baselines; the 'warm' instruction resulted in statistically insignificant changes in the opposite direction. Large, consistent individual differences in autonomic response were found.

Role of feedback in voluntary control of heart rate

The relative effectiveness of biofeedback techniques on the voluntary control of heart rate was examined by randomly assigning 32 Ss to one of four feedback conditions in a bi-directional heart-rate control task: (1) no feedback, (2) binary feedback--S was signaled when an interbeat interval had changed in the correct direction, (3) "real-time," proportional feedback--S was provided information about the relative duration of successive interbeat intervals, and (4) numerical, proportional feedback--each interbeat interval was represented as a numeral indicating its relationship to pre-trial mean by direction and magnitude. Significant over-all heart-rate changes were evidenced for both increase and decrease directions, but no differences were found between the feedback conditions. While these data suggest that feedback may be a relatively insignificant factor in voluntary heart-rate control, it was recommended that further investigation examine the role of feedback within the context of other training, mediating and motivational variables.

A simple feedback system for self-control of blood pressure

A relatively simple, open-loop, feedback system, based on closed-circuit television, which can be used to teach Ss to control their blood pressure is described, along with two experiments which demonstrate its efficacy. In the first experiment 10 normotensive Ss were able to increase systolic blood pressure with the aid of feedback over the level obtainable with the same instructions but without feedback. The second experiment provided a systematic replication of the efficacy of the feedback system. Groups of 13 normotensive Ss for 3 daily 20-min. trials were given either (1) proportional feedback via the new open-loop system or (2) binary feedback of systolic blood pressure on a once per minute basis or (3) were given no feedback but instructions to lower their blood pressure. Results showed a consistent advantage for blood pressure lowering of the new feedback system over binary feedback or no feedback. The latter two did not differ.

Differential effects of feedback and reinforcement in voluntary acceleration of human heart rate

Six single-subject experiments were conducted: In each experiment, after a stable baseline was established, S was given 8 20-min. trials on which he was to accelerate heart rate with no feedback; next 24 additional 20-min. sessions were given on which S received binary feedback of heart rate; depending upon the experiment, reinforcement in the form of small amounts of money was also given or withdrawn in blocks of 8 sessions; finally generalization was measured in a concluding block of 8 sessions. A significant instruction effect was found in 4 experiments. Further significant increases in heart rate were found in all 6 experiments when feedback was introduced. Although it was established experimentally that contingent presentation of money functioned as a reinforcer for a motor (bar-press) response, its contingent presentation did not yield a consistent advantage in accelerating heart rate.