Cardiovascular responses to avoidance conditioning in the dog: Effects of alpha adrenergic blockade

Laboratory dogs were trained to press a response panel to postpone shocks during daily one-hour avoidance conditioning periods. Each dog was also confined in the experimental environment for 5 hours prior to the avoidance periods. Blood pressure and heart rate were monitored continuously during these experiments from chronically indwelling arterial catheters. Extended training resulted in the emergence of a cardiovascular response pattern during the pre-avoidance interval characterized by gradual increases in blood pressure together with decreases in heart rate. Elevations in both blood pressure and heart rate were sustained during the avoidance periods. During sessions in which alpha adrenergic activity was suppressed by phenoxybenzamine, absolute levels of blond pressure were found to be lower than during control (non-drug) sessions, but a progressive rise in blood pressure continued to be observed during pre-avoidance. These results suggest that sustained cardiovascular responses during avoidance periods are associated with activation of the sympathetic nervous system, but that the gradual rise in blood pressure during pre-avoidance is due to other factors.     

The type a behavior pattern,sex differences,and cardiovascular response to and recovery from stress

Sixty-one subjects performed a Stroop Color-Word Interference task, a mental arithmetic task (serial subtraction of 7s), and a shock avoidance task (repeating digits backward while expecting to be shocked for mistakes). Systolic and diastolic blood pressure and pulse rate were recorded while subjects anticipated, undertook, and recovered from the shock avoidance task, and undertook and recovered from the Stroop and mental arithmetic tasks. The results revealed that, compared to Type B subjects, Type A subjects manifested higher diastolic blood pressure during the Stroop and shock avoidance tasks and higher pulse rate following the mental arithmetic and shock avoidance tasks. No significant interactions were found between sex and A/B Type. The results are congruent with the notion that greater sympathetic nervous system activity among Type A individuals, both men and women, contributes to greater coronary atherosclerosis and heart disease in this group.     

The effects of unavoidable shocks on a multiple schedule having an avoidance component

Two dogs were maintained on a multiple schedule having both a food reinforced and an avoidance component (Mult VI 1′ S^Δ Avoid_{SS20 RS20} S^Δ). The effects of superimposing an Estes-Skinner procedure for delivering unavoidable shocks on all components of the multiple schedule were observed. The buzzer-shock pairing of the Estes-Skinner procedure produced an increased rate of responding on the avoidance component of the schedule and also on the S^Δ components. No persistent change in rate was observed on the food component during the pre-shock stimulus. Control performances on all components could be regained by either extinguishing or eliminating the buzzer-shock pairing. Extinction of the avoidance responding had little effect on the increased rates of responding produced by the Estes-Skinner procedure on the S^Δ and avoidance extinction components and did not lead to a conditioned suppression of the food reinforced responding. Rate of responding during the pre-shock stimulus was observed to be relatively independent of changes in the maintaining schedules. Responding during the pre-shock stimulus could be conditioned and maintained after an extensive history of avoidance extinction.     

Cardiovascular generalization and differentiation: The relationship between heart rate and blood pressure

The present study was designed to study generalization and differentiation and to check the relation between heart rate and blood pressure in cardiovascular conditioning. Five naive mongrel dogs were presented with 10 sec 1000 cps tone regularly reinforced with 0.5-sec shock to a left foreleg. Four other 10-sec tones (600, 800, 1200, 1400 cps), never reinforced, were administered in a randomized and counterbalanced fashion using a differential reinforcing technique. The response measures were heart rate and three indices of blood pressure,i.e., systolic, diastolic, and pulse pressures.“Initial response” of heart rate showed rapid tachycardia to all tones, with no generalization and differentiation among five tones.“Terminal response” clearly indicated generalization gradients that tachycardia to 800 and 1200 cps tones were higher than those to 600 and 1400 cps tones, respectively. Some differences were noted among systolic, diastolic, and pulse pressures, with pulse pressure showing a trend of generalization and differentiation in the“initial response.” No statistical difference, however, was obtained in blood pressure scores. Beat-by-beat analyses of correlations between heart rate and diastolic blood pressure showed that the correlations successively decreased during the“terminal response.” Overall correlations between heart rate and three indices of blood pressure were obtained, with the highest correlation between heart rate and pulse pressure. Considering the above results in relation to the classical conditioning theory, it was tentatively concluded that“initial response” includes non-conditional factors, while“terminal response” reflects mainly a true conditional response, particularly, at a long CS-US interval. This interpretation leads to the hypothesis that conditional response with a short CS-US interval may attain better conditioning scores in terms of the summation effect between a non-conditional factor and a true conditional factor.     

Cardiovascular Responses to Threat: Effects of the Difficulty and Availability of a Cognitive Avoidant Task

Measures of heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were taken during an interval immediately preceding a period in which male subjects were to perform an easy or difficult memory task to avoid a noxious noise, or simply wait to receive the noise. As predicted, anticipatory elevations in SBP and HR were relatively higher in the difficult avoidance condition than in the easy and impossible avoidance conditions. In contrast, anticipatory DBP change-scores decreased linearly from easy to difficult to impossible avoidance conditions. Results are discussed in terms of a recent motivational theory suggesting that energy mobilization in the face of threat should be a function of what can, will, and must be done to cope.     

Classical conditioning of blood pressure inMacaca mulatta with cardiac rate controlled

The interaction of heart rate and blood pressure responses was studied in four male rhesus monkeys (M. mulatta) during classical delay conditioning and extinction. During initial conditioning sessions, heart rate was held constant by means of an external cardiac pacemaker; in follow-up conditioning sessions, the heart was free of constraint. Observations were made after these conditioning sessions, (a) during several sessions given over to continued training while different pacing rates were in effect; (b) during a series of extinction sessions in which the heart was paced and unpaced; and, (c) when a heart rate CR was simulated by manipulation of the pacer with no conditioned or unconditioned stimuli present. Throughout all sessions, systolic and diastolic pressures were measured at each heart beat. It was found that blood pressure conditioning was largely unaffected when heart rate changes were prevented during acquisition. Extinction of blood pressure responses was also seen to proceed relatively unimpeded when the heart was paced at a fixed frequency. During the postacquisition conditioning sessions, the several different pacing rates that were tested did not produce any significant differential effects in the blood pressure CRs. Simulated heart rate CRs were accompanied by small changes in pressures, sometimes opposite in direction from the pressure CRs observed during unpaced conditioning trials.     

追踪作业中几种心理负荷评估指标敏感性的研究

本研究在模拟追踪作业情境下 ,对主任务绩效测定、主观评定和若干生理测量在心理负荷评估中的敏感性进行了实验。实验采用重复测量的被试者内设计 ,2 0名被试 (男女各半 )在六档负荷下分别从事五分钟追踪作业。所选用的指标有追踪作业平均误差距离、追踪警告次数、主观负荷评定、心率、心率变异和血压。结果发现 :1主任务绩效在评估追踪作业心理负荷中具有最高的敏感性 ,主观评定次之 ,心率变化率和心率变异变化率也随负荷变化 ,血压指标随负荷变化的趋势不明显 ;2除血压指标外 ,其余各指标之间均存在明显的相关 ,这提示它们在评估追踪作业心理负荷中具有较大的可靠性。     

Evaluation of meditation and relaxation on physiological response during the performance of fine motor and gross motor tasks

This study investigated the effects of meditation/relaxation on physiological responses during the performance of a fine motor and a gross motor task. A pretest-posttest control group, randomized-blocks design was used to study a group of 16 meditators and a group of 16 nonmeditators, subgroups of each who relaxed prior to performing on a pursuit-rotor tracking device as a fine motor task and to performing the Luft cycle ergometer protocol to a heart rate of 70% of age-adjusted maximum heart rate as a gross motor task. During each of these tasks heart rate, systolic blood pressure, rate-pressure-product, and EMG activity of the frontalis muscle were monitored. No significant difference in the performance of either the fine motor or the gross motor task was noted for persons practicing meditation and persons who were nonmeditators but were given the opportunity to relax prior to a motor task. Likewise, no significant difference was noted in the pattern of response to the imposed fine motor or gross motor task by meditators or relaxed nonmeditators.     

Electroencephalographic and blood pressure correlates of operantly conditioned heart rate in the restrained monkey

Each of four monkeys was trained to slow its heart rate and to speed its heart rate. Mean blood pressure was positively correlated with heart rate during speeding and during slowing. These correlations increased from early training to late training for all animals during slowing; however, they did not change during speeding. High voltage in the 8–14 Hz band of the EEG was correlated negatively with heart rate; however, the correlations were insignificant or low. The correlations between EEG changes and heart rate changes increased (became more negative) during the late phase of slow training but did not change reliably during speeding training. Baseline levels in all physiological functions changed as a function of stage of training. Response patterns during escape behavior indicate dissociation of heart rate and blood pressure, whereas response patterns during avoidance behavior show correlation of heart rate and blood pressure. The findings indicate that the physiological effects of heart rate slowing and heart rate speeding are different and not merely mirror images of one another.     

Information Load Stress,Risk Taking,and Physiological Responsivity in a Visual-Motor Task1

The effects of four levels of information load on performance, risk taking, and physiological responsivity (blood pressure and heart rate) are investigated. Twenty-five adults participated in a handeye coordination task, presented as a video game. Increases in load resulted in performance decrements and increased proclivity to take risks. Participation in the task increased (diastolic) arousal. Load effects on arousal were negligible. Subjects with greater diastolic blood pressure elevations engaged in more risk taking. The potential of two separate groupings of stressor effects, directly producing cognitive performance changes in one case and producing affective/arousal impacts in the other case (with potential indirect effects on cognition and performance), is considered. Suggestions for future research are made.     

CHANGES IN BLOOD PRESSURE AND HEART RATE DURING FIXED‐INTERVAL RESPONDING IN SQUIRREL MONKEYS

Episodic and sustained increases in heart rate and mean arterial blood pressure can occur with recurring patterns of schedule‐controlled behavior. Most previous studies were conducted under fixed‐ratio schedules, which maintained a consistent high rate of responding that alternated with periods of no responding during times when the schedule was not in operation. The present study examined changes in heart rate and blood pressure under fixed‐interval schedules which maintained a range of rates that varied from little or no responding at the beginning of the fixed interval to high rates at the end of the interval. The relations of cardiovascular function to rate of responding were examined. Squirrel monkeys prepared with arterial catheters were trained to respond under fixed‐interval schedules of electric‐shock presentation. The duration of the interval was varied across sessions and cardiovascular parameters were examined. Local rates of responding were typically near zero during timeout periods, low at the beginning of each fixed‐interval cycle, and then increased as the fixed interval progressed. At most schedule durations, arterial blood pressure and heart rate levels were lowest at the beginning of the interval cycles, increased as the rate of responding increased, and then decreased during the timeout periods. At all parameters studied, there was a direct relationship between changes in response rate within fixed‐interval cycles and changes in heart rate and blood pressure. The results suggest that a much closer concordance of these cardiovascular parameters and schedule‐controlled responding is obtained by examining ongoing behavior as it occurs within the contingencies by which it is maintained.     

Is your choice my choice? The owners’ effect on pet dogs’ (Canis lupus familiaris) performance in a food choice task

This study investigates the influence of owners on their dogs’ performance in a food choice task using either different or equal quantities of food. Fifty-four pet dogs were tested in three different conditions. In Condition 1 we evaluated their ability to choose between a large and small amount of food (quantity discrimination task). In Condition 2 dogs were again presented with a choice between the large and small food quantity, but only after having witnessed their owner favouring the small quantity. In Condition 3 dogs were given a choice between two equally small quantities of food having witnessed their owner favouring either one or the other. A strong effect of the owner on the dogs’ performance was observed. In Condition 1 dogs as a group chose significantly more often the large food quantity, thus showing their ability to solve the quantity discrimination task. After observing their owner expressing a preference for the small food quantity they chose the large quantity of food significantly less than in the independent choice situation. The tendency to conform to the owner’s choice was higher when the dogs had to choose between equally small quantities of food (Condition 3) rather than between a large and a small one (Condition 2). These results provide evidence that dogs can be influenced by their owners even when their indications are clearly in contrast with direct perceptual information, thus leading dogs to ultimately make counterproductive choices.     

Training domestic dogs (Canis lupus familiaris) on a novel discrete trials odor-detection task

Dogs can be trained to reliably detect a wide variety of odors. Little scientific research, however, has been published on the rate at which dogs can learn to detect an odor, the variables influencing this rate, and how this rate may vary across dogs. In two experiments, we developed a procedure that allows the study of individual differences in the acquisition of an odor detection task in dogs. We demonstrate that differential reinforcement can be used to train a rooting response in a bin under the control of a novel odorant in discrete trials. In initial testing, we showed that as a group, twenty dogs performed significantly above chance within 24 trials, with two dogs meeting an individual criterion for above chance performance. In a follow-up experiment, we compared burying accessible food inside the target bin (with inaccessible food in the non-target bin) to the experimenter delivering food by hand following correct responses. We assessed the effect of this procedural variation on both an odor discrimination and a visual discrimination. Dogs learned faster on the odor task when the experimenter delivered food, compared to when food was placed directly in the bins. Performance on the visual task was lower than on the odor task and was unaffected by how food was delivered. Our discrete-trials procedure with experimenter-delivered food may be a useful method to study rapid acquisition of an odor-detection in dogs.     

Acquisition and discrimination of appetitively and aversively conditioned heart rate responses in rhesus monkeys

This report describes the acquisition of a conditional heart rate response to both classical aversive and appetitive conditioning in eight rhesus monkeys(Macaca mulatta). The behavioral paradigm consisted of two discrete one minute tones followed by the corresponding unconditional stimuli,i.e., electric shock or Purina monkey chow. A third tone followed by neither food nor shock served as a discriminative stimulus (DS). The conditional heart rate responses developed in two phases. The first phase was characterized by similar responses to both conditional stimuli and the DS. Control heart rate rose during this period. During the second phase, control heart rate decreased (five animals), the DS response disappeared, and different conditional heart rate patterns to food and shock emerged. The existence of distinct conditional response patterns indicates probable differences in the autonomic nervous regulation of the heart during aversive and appetitive conditioning.     

Generic cognitive adaptations to task interference in task switching

The present study investigated how the activation of previous tasks interferes with the execution of future tasks as a result of temporal manipulations. Color and shape matching tasks were organized in runs of two trials each. The tasks were specified by a cue presented before a task run, cueing only the first trials of each run. Response times (RTs) and error rates were measured for task switching and task repetition conditions. Task interference was varied as a function of response-cue interval (RCI of 300 and 900 ms), that is, the interval between the task runs. Keeping the response-stimulus interval within the task runs constant at 300 ms allowed the disentangling of the direct effects of RCI manipulation on performance (first trials) from the general effects on performance (both trials in the run). The data showed similar performance improvement due to RCI increase on both trials in the task run. Furthermore, increasing RCI improved both switch and repetition performance to a similar extent. Together, our findings provide further evidence for accounts stressing generic effects of proactive task interference in task switching.     

Schizokinesis: Fragmentation of performance in two strains of pointer dogs

During the behavior shaping toward bar jumping to avoid shock at the termination of a tone, ten genetically nervous (“E”) and ten stable (“A”) dogs showed different performances in the acquisition of the adaptive motor response. When tested two months later and with concurrent monitoring of their electrocardiograms, these animals also showed differences in (1) baseline heart rate, (2) direction and degree of heart rate change to the conditioned tone stimulus (more often deceleration in the E dogs), and (3) response to the unconditioned shock stimulus. After having performed in an almost satisfactory manner for a few trials, thenervous animals often would suddenly freeze in rigid postures. These animals could frequently be made to emit the adaptive behavior by “breaking the frozen posture” through pushing, jumping, or pulling manipulation. Sometimes a forced righting reflex dramatically encouraged an integrated performance of varying duration. Thestable strain of dogs showed little or none of the rigidity and usually learned the smooth adaptive response. The stable A dogs showed retention of the cardiac Cr, but not of the motor Cr (which they re-formed after one or two reenforcements); the nervous E dogs also retained the cardiac Cr, but persisted in the maladaptive motor performance. The fragmented disorganized behavior in acquiring the adaptive motor act and thedifferential retention of the autonomic and motor responses are considered examples ofschizokinesis as conceptualized by Gantt. This schism is seen in clearer form in behavioral acquisition than in the usual frequency measure of the well-practiced act.     

Psychophysiological reactions to understimulation and overstimulation

Catecholamine output, heart rate, and performance efficiency were examined in 28 Ss during two contrasting stimulus conditions, one of understimulation, and one of overstimulation. During understimulation the subject spent 3 hr performing a vigilance task, and during overstimulation he was exposed for the same time period to a complex sensorimotor test. Both understimulation and overstimulation produced a significant increase of adrenaline and noradrenaline release as compared with a control condition involving a medium amount of stimulation. Subjects who excreted relatively more adrenaline performed significantly better during understimulation, whereas subjects with relatively lower excretion rates of adrenaline tended to perform better under overstimulation. When performance efficiency was related to heart rate it was shown that high-heart rate subjects performed better during understimulation, while low-heart rate subjects performed better during overstimulation.     

Waiting for more: the performance of domestic dogs (Canis familiaris) on exchange tasks

Five domestic dogs (Canis familiaris) were tested in a cooperative exchange task with an experimenter, as previously tested in non-human primates. In the first task, the dogs exchanged to maximise payoffs when presented with food items of differing quality. All consistently exchanged lower-value for higher-value rewards, as determined by their individual food preference, and exchanges corresponded significantly with the spontaneous preferences of three dogs. Next, all subjects demonstrated an ability to perform two and three exchanges in succession, to gain both qualitative and quantitatively increased rewards (group mean = 72 and 92% successful triple exchanges, respectively). Finally, the ability to delay gratification over increasing intervals was tested; the dogs kept one food item to exchange later for a larger item. As previously reported in non-human primates, there was considerable individual variation in the tolerance of delays, between 10 s and 10 min for the largest rewards. For those who reached longer time lags (>40 s), the dogs gave up the chance to exchange earlier than expected by each subject’s general waiting capacity; the dogs anticipated delay duration and made decisions according to the relative reward values offered. Compared to primates, dogs tolerated relatively long delays for smaller value rewards, suggesting that the socio-ecological history of domestic dogs facilitates their performance on decision-making and delay of gratification tasks.     

Task difficulty, cardiovascular response, and the magnitude of goal valence

Sixty-four young women expected to perform an easy, moderately difficult, or extremely difficult memory task with the opportunity to earn a small incentive for good performance. Cardiovascular (heart rate, systolic and diastolic blood pressure) and subjective measures were taken immediately prior to task performance. Both systolic blood pressure (SBP) responses and ratings of goal attractiveness were nonmonotonically related to expected task difficulty, with the most pronounced SBP elevations and highest goal attractiveness in the moderately difficult task condition. Product-moment correlations among cardiovascular response measures revealed a strong positive association between systolic and diastolic pressure (but not heart rate) change in the easy condition, positive relationships among all measures in the moderately difficult condition, and no significant correlations in the extremely difficult condition. Subjective measures of arousal were not affected by the task difficulty manipulation. Principal findings are discussed in terms of a theoretical model proposed by Brehm (1979) that states that motivation varies as a nonmonotonic function of the difficulty of goal attainment. Intercorrelations among cardiovascular response variables are considered in terms of their possible indication of the mechanisms underlying blood pressure changes associated with variations in motivation.     

Blood flow,blood pressure and heart rate changes accompanying hind leg flexion in conditional and unconditional reflexes

Results

During flexion of the hind leg to US or CS, as well as during spontaneous lifting of the leg, the blood flow in the appropriate femoral artery suddenly increases for 10–14 seconds, systemic blood pressure shows transient decrease, while heart rate and respiratory movements are accelerated. To perform one flexion and subsequent extension about 7 ml extra blood flow is necessary during UR and 5 ml during CR. During acute extinction of the CR the described vegetative changes become less and less, parallel with the gradual decrease of flexor movement of the hind leg. The sequence of extinction of the individual measured parameters was as follows: flexion, blood pressure, blood flow, heart rate, and lastly, respiration. In the mechanism of the vegetative changes accompanying the conditional hind leg flexion three main components are involved: (1) muscular-visceral reflexes originating from different receptors of the contracting muscles, (2) the emotional changes, and (3) the conditional component as a separate conditional reflex for each measured parameter. Principles underlying the formation of conditional reflexes are discussed under the headings ofschizokinesis, peripheral andcentral stimulations.Organ responsibility is the basis for the formation of the conditional reflex.