Response-shock delay as a reinforcer in avoidance behavior

After rats received preliminary training to avoid shock on a discrete-trial retractable-bar avoidance procedure, the procedure was changed such that responses retracted the lever but did not affect the rate of shock. Responses only delayed the onset of shock. About half of the animals under these procedures responded consistently on almost 100% of the discrete-trial cycles over days. When short latencies maximized the response-shock delay, animals tended to make short-latency responses. When long latencies maximized the response-shock delay, animals tended to make long-latency responses. When all response latencies produced the same response-shock delay, animals made differing average-latency responses. And, when responses did not delay shock, most of the animals primarily engaged in shock-elicited responding while the other animals engaged in preshock responding.     

Brain stimulation as a reinforcer: intermittent schedules

Rats with chronically implanted, bipolar electrodes in the septal and medial forebrain bundle areas, in addition to the region of the mammillary bodies of the posterior hypothalamus, were trained to press a permanently mounted lever in order to produce a second, retractable lever. Rewarding brain stimulation was programmed on the retractable lever; following completion of the programmed number of CRF response-stimulations, that lever was retracted from the box. Responding on the permanent lever could reintroduce the retractable lever. Fixed interval, fixed ratio, DRL, and variable interval schedules were programmed on the permanent lever in the range of schedule parameters often used with conventional reinforcers. Typical effects are described, and it is concluded that there are no striking differences between brain-stimulation reinforcement and the conventional reinforcers.     

On insirumental response interaction as explaining the influences of Pavlovian CSs upon avoidance behavior

The finding that Pavlovian signals for food or shock influence avoidance responding might be explained either by interaction of conditioned central mediational states or interaction of learned instrumental responses. Using three groups of dogs, the two hypotheses were pited one against the other in a three-stage transfer-of-control experiment. In the initial conditioning phase, tones were established as signals for food, shock, or neither; additionally the tones also cued a common instrumental response. Following avoidance training, the tone was tested for its influence upon avoidance. If the lone had signaled food, avoidance was suppressed; if shock, avoidance was facilitated; if neither, avoidance was unaffected. This was interpreted as supporting the hypothesis that interaction of central states mediates the transfer-of-control.     

The functional properties of a time out from an avoidance schedule

Investigations are reported of some of the discriminative (cue) and reinforcing properties of stimuli (TO_av) correlated with the discontinuation of a free-operant avoidance schedule. After several unsuccessful initial attempts to demonstrate the positively reinforcing effect of TO_av, a special technique was developed. The subjects were trained by means of a free-operant avoidance procedure to press a lever and postpone electric shock; by pressing a second lever, they could produce a cue correlated with the TO_av period. The importance of a distinct cue correlated with TO_av was demonstrated in experiments in which this signal was eliminated from the procedure. The reinforcing function of the TO_av period was explored by showing its effectiveness under various schedules of reinforcement.

Other observations were made concerning the course of extinction of both TO_av-producing responses and avoidance behavior.

In further experiments in which TO_av was used as a reinforcer, the TO_av behavior was also brought under separate stimulus control. The development of the various discriminations involved in the resulting performance were described.

     

Superconditioning from a reduced reinforcer

In four autoshaping experiments pigeons received conditioned inhibition training of the form A++, AB-, where ++ is a strong reinforcer and - is nonreinforcement. Subsequent AB+ training, in which + is a moderate reinforcer, resulted in enhanced conditioning of A, relative to an A stimulus receiving no treatment, one receiving A+ treatment, and one receiving A++ treatment. This enhancement of conditioning to Aconstitutes a demonstration of “superconditioning”. The presence of the inhibitory B sufficiently enhanced the reinforcing power of the moderate reinforcer (+) that it was able to further increase the excitation controlled by A. This occurred even though A had previously been paired with a stronger reinforcer (++). Superconditioning was also observed when A and B were extinguished prior to treatment with + or were originally neutral stimuli followed by + in the presence of an inhibitor trained elsewhere.     

Environments as reinforcer systems in the study of job satisfaction

This paper examined differences in the degree to which fifteen specific sources of job satisfaction were related to and predictive of the overall satisfaction of department chairmen in the six model environments proposed by Holland (1973). The fifteen specific sources of job satisfaction were regressed on overall satisfaction, separately for chairmen in each environment, through the use of incremental stepwise multiple regression procedures. The results indicated that the overall satisfaction of chairmen in these six environments was differentially related to unique weightings and combinations of the fifteen predictor variables. It was concluded that environments, composed of essentially similar groups of people in different organizations, serve as job satisfaction reinforcer systems in a manner similar to organizations as illustrated by Dawis.     

Disgusting clusters: trypophobia as an overgeneralised disease avoidance response

Individuals with trypophobia have an aversion towards clusters of roughly circular shapes, such as those on a sponge or the bubbles on a cup of coffee. It is unclear why the condition exists, given the harmless nature of typical eliciting stimuli. We suggest that aversion to clusters is an evolutionarily prepared response towards a class of stimuli that resemble cues to the presence of parasites and infectious disease. Trypophobia may be an exaggerated and overgeneralised version of this normally adaptive response. Consistent with this explanation, individuals with trypophobia, as well as comparison individuals, reported aversion towards disease-relevant cluster stimuli, but only the trypophobic group reported aversion towards objectively harmless cluster stimuli that had no relevance to disease. For both groups the level of aversion reported was predicted uniquely by a measure of disgust sensitivity. Scaled emotion ratings and open-ended responses revealed that the aversive response was predominantly based on the disease avoidance emotion, disgust. Many open-ended responses also described skin sensations (e.g. skin itching or skin crawling). These findings support the proposal that individuals with trypophobia primarily perceive cluster stimuli as cues to ectoparasites and skin-transmitted pathogens.     

Reinforcement and response rate interaction in multiple random-interval avoidance schedules

Two experiments were conducted to investigate the interaction between response rate and reinforcement frequency in multiple random-interval avoidance schedules. Responses cancelled delivery of shocks that could be scheduled at different random intervals in each component. When shock-frequency reduction was taken as the measure of reinforcement, the relationship between response rate and frequency of reinforcement was described by the same equations used by Herrnstein (1970) to describe responding with positive reinforcement.     

Autoshaping the pigeon's gape response: acquisition and topography as a function of reinforcer type and magnitude.

The pigeon's key-pecking response is experimentally dissociable into transport (head movement) and gape (jaw movement) components. During conditioning of the key-pecking response, both components come under the control of the conditioned stimulus. To study the acquisition of gape conditioned responses and to clarify the contribution of unconditioned stimulus (reinforcer) variables to the form of the response, gape and key-contact responses were recorded during an autoshaping procedure and reinforcer properties were systematically varied. One group of 8 pigeons was food deprived and subgroups of 2 birds each were exposed to four different pellet sizes as reinforcers, each reinforcer signaled by a keylight conditioned stimulus. A second group was water deprived and received water reinforcers paired with the conditioned stimulus. Water- or food-deprived control groups received appropriate water or food reinforcers that were randomly delivered with respect to the keylight stimulus. Acquisition of the conditioned gape response frequently preceded key-contact responses, and gape conditioned responses were generally elicited at higher rates than were key contacts. The form of the conditioned gape was similar to, but not identical with, the form of the unconditioned gape. The gape component is a critical topographical feature of the conditioned key peck, a sensitive measure of conditioning during autoshaping, and an important source of the observed similarities in the form of conditioned and consummatory responses.     

Carbon dioxide as a reinforcer in escape conditioning

The effects of varying CO₂ concentration, and intervals between CO₂ presentations, were determined from the performance by five pigeons of a learned motor act which eliminates CO₂ from the inspired air. The length of time from the onset of an externally-produced increase in inspired CO₂ to the performance of the learned motor response terminating the CO₂ presentation was inversely related to the CO₂ concentration presented (3 per cent and 5 per cent) and directly related to the inter-trial interval (3 minutes and 1.5 minutes). Chemoreceptors on the ventrolateral surfaces of the medulla are postulated to be the initial site of stimulation in the chain of events leading to the behavioral bioregulation of inspired CO₂ concentration.     

Aggression as a reinforcer: operant behavior in the mouse-killing rat

Two experiments examined mouse killing as a reinforcer of key pressing by rats that killed mice. In Experiment I, mouse-killing rats performed the key-pressing response when each press was reinforced with presentation of a mouse. Offered a choice between a key that yielded presentation of mice and one that did not, the rats preferred the key that yielded mice. When the contingency was reversed, the rats preferred the other key and continued to kill mice. In Experiment II, mouse-killing rats that did not kill rat pups performed a key-pressing response reinforced with presentation of mice on a variable-interval schedule. In tests for responding reinforced on that schedule with presentation of normal mice, anesthetized mice, dead mice, or rat pups, these rats that killed mice but not rat pups exhibited a decline in response rate when rat pups were the reinforcer. Altering the condition of the mice did not significantly affect performance.     

Sidestepping awkward encounters: avoidance as a response to outperformance‐related discomfort

When people believe that their higher performance poses a threat to another person, they may experience discomfort or concern that has been termed Sensitivity to being the Target of a Threatening Upward Comparison (STTUC). One way to reduce STTUC discomfort might be to avoid contact with the outperformed person, a possibility examined in three studies of undergraduates. In laboratory contexts, STTUC discomfort predicted reluctance to meet an outperformed peer (Study 1) and preference for a different partner in future competitions (Study 2). In Study 3, which focused on naturalistic outperformance situations, STTUC distress again predicted avoidance. Additionally, avoidance of contact predicted less satisfaction with outcomes, especially in relationships where people knew each other well.     

Sequential reacquisition as a function of timeout from avoidance

Rats learned to reacquire four similar three-member response sequences. Each sequence member was associated with a different response lever, and the correct sequence of levers (i.e., 3-1-2, 2-1-3, 1-3-2, and 2-3-1) changed each session. The first two correct responses of each sequence postponed shock for a fixed period of time. The third correct response initiated a signalled timeout from avoidance. Incorrect responses did not affect the shock interval or reset the sequence. The effects of manipulating timeout duration on the sequential reacquisition baseline were investigated. All subjects displayed biphasic reacquisition performances similar to those controlled by food. The phases were characterized by an initial increase in accuracy, which reached a stable level during the latter portion of each session. Timeout duration affected rate of sequence completion and shock density, but not percentage of errors. Rate of sequence completion was fastest with intermediate timeouts (15 to 60 sec), and slowest with extreme durations (1 or 120 sec). Shock densities peaked with extreme durations and were at minimum with intermediate timeout values. The percentage of errors was the same across timeout durations. These data extend the generality of sequential reacquisition as a procedure for studying learning, and demonstrate timeout from avoidance to be a controlling variable.     

Vibration as a reinforcer with a profoundly retarded child

Data are presented which indicate that lever-pressing behavior of a profoundly retarded child could be reinforced by the contingent application of vibratory stimulation for each response. With vibration available 24 hr per day, no decrement in daily rate of responding for vibration was seen over a three-week period. Suggestions are made for further use of this finding in working with the profoundly retarded.     

Behavioral similarity as a reinforcer for preschool children

Three experiments evaluated whether behavioral similarity provided by an adult could serve as a reinforcer for the modelling behavior of four preschoolers. In each experiment, sessions consisted of two kinds of trials: (1) experimenter-modelled trials, when the child's imitation of modelled motor responses was reinforced with praise and tokens, and (2) child-modelled trials when experimenter imitation of child-modelled responses was contingent upon the child's modelling one of three alternative responses: operation of a ball, horn, or clicker. Experiment I showed that the children consistently modelled whichever responses the experimenter imitated. Experiment II determined whether that performance was due to differences in the amount of experimenter behavior following imitated versus nonimitated child models or to experimenter imitation. Neither reducing nor increasing the amount of experimenter behavior following the children's nonimitated models altered their modelling of imitated responses. Experiment III evaluated whether experimenter imitation of child models was a reinforcer because the child's imitative responses were reinforced on experimenter-modelled trials. In Experiment III, the children's nonimitation of experimenter-models was reinforced with praise and tokens on a schedule of differential reinforcement of other behavior, yet they continued to model experimenter-imitated responses on child-modelled trials. These results indicate behavioral similarity was reinforcing, though no conditioning history through which it acquired that function was demonstrated.