Operant conditioning in the newly hatched chicken

Techniques are described for conditioning key-pecking reinforced with food and for recording cheeping in newly hatched chickens. A mirror in the test box is essential when conditioning isolated chickens up to five or more days old. Conditioning proceeds more rapidly when frequently pecked objects and materials that move when scratched are not present. Stimulus control over key-pecking is present in the three-day-old chicken and multiple fixed-ratio, fixed-interval schedule control develops in succeeding days. In young chickens, pecking and cheeping are inversely related. The newly hatched chicken is useful for pharmacological studies and appears to offer other advantages for behavioral studies.     

Operant control of preening in pigeons

Preening in four pigeons was observed and recorded during operant level determinations, continuous and variable interval reinforcement, and extinction. The rate at which preening responses occur seems to be controlled by reinforcement in the same way as other operant behavior. Preening during VI reinforcement and extinction appeared to be similar to preening in many natural situations. With respect to the part of the body preened, considerable stereotypy of responding was shown by all birds, particularly during VI training; there was, however, a conspicuous absence of consistency in the development of stereotypy both within and between individual birds, perhaps due to the nature of the response.     

Operant control of vocal behavior in the cat

Evidence of operant control of vocal behavior in the cat is presented: (1) On mult FR 12 S^Δ schedule, cats miaowed rapidly during periods of S^D and much less or not at all during S^Δ. (2) This control was re-established following reversal of stimuli. (3) The frequency distribution of response durations was shifted to both shorter and longer values by the differential reinforcement of shorter or longer response durations respectively. Since both the frequency and duration of vocal responses were shown to be under the control of the schedule of reinforcement, it is concluded that at least some of the vocal behavior of the cat is susceptible to operant control.     

Operant control of eye movements

In a monitoring situation eye movements were required in order for signals to be presented. Detection of signals was the reinforcement. A multiple schedule of fixed-interval reinforcement, differential reinforcement of low rate, and fixed-ratio reinforcement was established for eye movements. Results demonstrated that an eye movement can act as an operant controlled by its consequences. Operant control of eye movements has important implications for human factor analysts concerned with "attention".     

Operant control of smoking in great apes

A methodology was developed for bringing smoking behavior in great apes under the control of a contingent food reinforcer. In this procedure, Ss were required to maintain long continuous draw durations (5 sec) against lighted cigarettes in order, to obtain candy rewards. By beginning with short criterional durations and gradually, working up to the desired response criterion, Ss were successfully habituated to the aversive aspects of smoking. The results indicated that it is possible to both shape and maintain smoking behavior with response-contingent reinforcement. The successful implementation of this procedure suggests that the pulmonary route can be used for drug administration with nonhuman primate species.     

Operant and Pavlovian factors in cross-response transfer of inhibitory stimulus control

Experiment 1 used a within-response procedure to compare inhibitory stimulus control of the extinction cue in multiple variable interval-extinction (mult VI EXT) and the variable time cue in multiple variable interval-variable time (mult VI VT). Experiment 2A made the same comparison using a crossresponse procedure. In addition, Experiment 2A also tested the extinction cue in multiple variable time-extinction (mult VT EXT), and Experiment 2B tested the variable time cue in mult VT EXT. Unlike the mult VI EXT and mult VI VT conditions, the mult VT EXT condition was administered in the absence of a response manipulandum. The main findings of the present study were: (1) cross-response suppression by the variable time cue in mult VI VT; (2) greater response suppression by the extinction cue in mult VI EXT than by either the variable time cue in mult VI VT or the extinction cue in mult VT EXT; and (3) response facilitation by the variable time cue in mult VT EXT. These findings indicate that inhibitory stimulus control based on an operant source (i.e., absence of an R-S contingency) does transfer across responses, and that such transfer cannot be explained in terms of competing responses. These findings also indicate that operant and Pavlovian sources of stimulus control summate algebraically to determine the inhibitory strength of the extinction cue in mult VI EXT. Finally, the third finding is not consistent with notions that emphasize the importance of location and localization of cues explicitly paired with positive events.     

Eye movements of monkey observers viewing vocalizing conspecifics

Primates, including humans, communicate using facial expressions, vocalizations and often a combination of the two modalities. For humans, such bimodal integration is best exemplified by speech-reading - humans readily use facial cues to enhance speech comprehension, particularly in noisy environments. Studies of the eye movement patterns of human speech-readers have revealed, unexpectedly, that they predominantly fixate on the eye region of the face as opposed to the mouth. Here, we tested the evolutionary basis for such a behavioral strategy by examining the eye movements of rhesus monkeys observers as they viewed vocalizing conspecifics. Under a variety of listening conditions, we found that rhesus monkeys predominantly focused on the eye region versus the mouth and that fixations on the mouth were tightly correlated with the onset of mouth movements. These eye movement patterns of rhesus monkeys are strikingly similar to those reported for humans observing the visual components of speech. The data therefore suggest that the sensorimotor strategies underlying bimodal speech perception may have a homologous counterpart in a closely related primate ancestor.     

Operant control of response latency in monkeys: evidence for a central explanation

Two monkeys (M. mulatta) were trained to press a telegraph key after onset of a tone and release it quickly in response to a subsequent light or click stimulus occurring after a variable interval. After training first with a fixed time limit on response latency for key release and then with a continuously adjusting limit, reaction time to click was 160 msec and to light, about 200 msec. Temporal contingencies or "payoff bands" were then introduced which reinforced only responses with latencies which fell between two limits 50 msec apart. Feedback was given as to whether each latency was too slow, within the band, or too fast. A trained monkey could precisely center its latency distribution on any 50 msec-wide payoff band located from 200 to 600 msec after the stimulus, with from 60 to 80% of its responses achieving reinforcement. Distribution statistics were comparable to those of trained human subjects. Because such precise timing might be accomplished by a peripheral adjustment, such as changing the manner of holding the key, latency of electromyographic activation was measured in participating arm muscles in one monkey. Electromyographic activation preceded key release by a constant interval, regardless of response latency, indicating a more central mechanism for timing of brief intervals.     

Operant and nonoperant vocal responding in the mynah: Complex schedule control and deprivation-induced responding

Several recent studies have been concerned with operant responses that are also affected by nonoperant factors, (e.g., biological constraints, innate behavior patterns, respondent processes). The major reason for studying mynah vocal responding concerned the special relation of avian vocalizations to nonoperant emotional and reflexive systems. The research strategy was to evaluate operant and nonoperant control by comparing the schedule control obtained with the vocal response to that characteristic of the motor responses of other animals. We selected single, multiple, and chain schedules that ordinarily produce disparate response rates at predictable times. In multiple schedules with one component where vocal responding (“Awk”) was reinforced with food (fixed-ratio or fixed-interval schedule) and one where the absence of vocal responding was reinforced (differential reinforcement of other behavior), response rates never exceeded 15 responses per minute, but clear schedule differences developed in response rate and pause time. Nonoperant vocal responding was evident when responding endured across 50 extinction sessions at 25% to 40% of the rate during reinforcement. The “enduring extinction responding” was largely deprivation induced, because the operant-level of naive mynahs under food deprivation was comparable in magnitude, but without deprivation the operant level was much lower. Food deprivation can induce vocal responding, but the relatively precise schedule control indicated that operant contingencies predominate when they are introduced.     

Operant conditioning in the bat Phyllostomus hastatus

Bats of the species Phyllostomus hastatus were trained to press a pigeon key with food as the reinforcer. Patterns of responding under fixed-ratio, fixed-interval, and variable-interval schedules of reinforcement were similar to those typically shown by other species. In a simple auditory discrimination, responding readily came under stimulus control. It is suggested that the behavioral method could be applied to various problem areas of bat behavior.     

Operant behavior in the great horned owl

An apparatus and method successful in producing free operant behavior in a Great Homed Owl are described. Key pecking responses were reinforced with balls of ground beef. Some sample data are shown.     

Operant conditioning in redwinged blackbirds

An operant conditioning technique for use with passerine birds is described. Two redwinged blackbirds were successfully conditioned to perch-hop for food reinforcement. Continuous reinforcement and fixed-ratio schedules involving substantial ratio requirements were used to maintain this response. The behavior of the two redwinged blackbirds was comparable to that of more conventional organisms working on similar schedules of reinforcement.