Pecking Response Research Articles

Pecking and feeding in chicks

Pecking is not controlled by nutritional state in a newly hatched chick, but by 3 days posthatch it normally is. This paper tests the hypothesis that first a chick must learn that pecking leads to ingestion; then, other (nonlearned) processes are automatically responsible for differential pecking rates to nutritive and nonnutritive items. The first experiment shows that experience pecking and ingesting sawdust is sufficient for differential pecking to develop. The second experiment shows that swallowing without pecking (using a force-feeding technique) does not lead to differential pecking. The third experiment shows that pecking without swallowing (using sand glued down to the floor) also does not lead to differential pecking. Finally, the last experiment shows that food deprivation affects pecking rate only after pecking and ingestion have been associated. These results support the above hypothesis that pecking followed by ingestion leads to the “attachment” of the pecking response to the feeding system. Motivational independence of pecking and the hunger system, the association of pecking with ingestion, and the development of behavior systems are discussed. It is concluded that the function of a behavior may not be related to its causes.

Dispersal of the Salamander, Hynobius nebulosus tokyoensis

natural history of four species of whiptail lizards, Cnemidophorus (Sauria: Teiidae) in Trans Pecos, Texas. Southwest. Natural. 2:105-121. . 1957b. Some aspects of competition in natural populations of whiptail lizards (genus Cnemidophorus). Texas J. Sci. 410-447. MITCHELL, J. C. 1976. Niche overlap and ecology of bisexual and parthenogenetic Cnemidophorus (Sauria: Teiidae). Master's Thesis, Arizona State Univ., Tempe. 145 pp. . 1979. Ecology of southeastern Arizona whiptail lizards (Cnemidophorus): population densities, resource partitioning and niche overlap. Can. J. Zool. 57:1487-1499. OPPENHEIM, R. W. 1968. Color preferences in the pecking response of newly hatched ducks (Anos platyrhynchos). J. Comp. Physiol. Psychol. Monogr., Suppl. 66 (pt. 2):1-17. PIANKA, E. R. 1970. Comparative autecology of the lizard Cnemidophorus tigris in different parts of its geographic range. Ecology 51:703-720. RAND, A. S., G. C. GORMAN, AND W. M. RAND. 1975. Natural history, behavior, and ecology of Anolis agassizi. Smith. Contr. Zool. 176:2738.

Interocular transfer of pattern discrimination learning in chicks

A previous study 14 found that chicks pecking a key for heat did not show interocular transfer of a pattern discrimination, indicating that the monocularly acquired discrimination was stored as a unilateral engram which was not available to the untrained eye/hemisphere system. In the present study, chicks were trained monocularly on a pattern discrimination and tested for interocular transfer exactly as in the previous experiment, except that a correct pecking response was reinforced by presentation of food. There was good interocular transfer of the discrimination under these conditions. These results are interpreted as indicating that the biological relevance of a learning situation influences the extent of interocular/interhemispheric communication of information. In addition to the findings with respect to transfer, the present study revealed some unexpected laterality effects. Chicks trained first through the right eye (left hemisphere) learned the pattern discrimination faster and showed more savings during the interocular transfer test than chicks trained first through the left eye (right hemisphere). These findings are discussed in terms of possible hemispheric specialization and asymmetry of interhemispheric communication in the avian brain.

Discriminative stimulus properties of cocaine: Effects of apomorphine, haloperidol, procaine and other drugs

In pigeons trained to discriminate between the presence and absence of 3 mg/kg of cocaine, combinations of intramuscularly injected (i.m.) procaine (0.7–7.0 mg/kg) plus cocaine (0.3–3.0 mg/kg) did not alter the drug (cocaine)-dose generalization curve as compared to cocaine alone although tests with large doses of procaine given alone (30.0 and 56.0 mg/kg) engendered dose-related responding appropriate to cocaine. Apomorphine (0.56 mg/kg, i.m.) also elicited more than 50% cocaine-appropriate responding, as did doses of 10 mg/kg of intragastrically administered cocaine, given by gavage at the opening of the proventriculus; of the two treatment-test intervals (15 and 30 min) examined the generalization effect was greater at 30 min as compared to 15 min after administration. d-Lysergic acid diethylamide (0.1 mg/kg) morphine (3.0 mg/kg), pentobarbital (10.0 mg/kg), and Δ 9-tetrahydrocannabinol (0.3 mg/kg) caused less than 16% pecking responses on the cocaine-appropriate key. The discriminative stimulus effects of cocaine (3.0 mg/kg) were attenuated in a dose-related manner by the neuroleptic haloperidol (dose range tested: 0.1–1.0 mg/kg). Neither the antagonism, nor the substitution tests with haloperidol were accompanied by a significant change in the percentage of responding on the initially selected position (key) by the pigeons.

Forgetting of visual discriminations by pigeons.

A series of three experiments examined the forgetting of visual discriminations by pigeons. The problems consisted of feature discriminations, with dot displays as the discriminative stimuli, and involved a successive go-no-go pecking response. It was found, in all three experiments, that pigeons trained to refrain from pecking an S- display resumed pecking at this display after retention intervals. It was argued that these data represent the first direct demonstration of forgetting of a discrimination by pigeons. In addition to the simple demonstration of forgetting, it was found in Experiment 1 that the amount of forgetting progressively increased, in a negatively accelerated fashion, over intervals of 1, 10, and 20 days. Also, more S- responses occurred during relearning a reverse discrimination than after relearning a nonreverse discrimination. In Experiment 2, acquisition was retarded and more forgetting occurred for discriminations that involved more highly similar stimuli. In Experiment 3, a change in contextual cues between acquisition and retention testing enhanced forgetting when the contextual cues present during original acquisition were conspicuous; when these cues were relatively inconspicuous, a change in context had no effect on forgetting.

Drug effects on the repeated generalization of a visual discrimination acquired under one trial per day conditions.

Six pigeons were trained to respond under concurrent fixed-ratio extinction schedules of food reinforcement (FR 50) on the side keys of a three key chamber. Presence or absence of continuously-flashing, colored lights on the center key signalled which key pecking response (left or right) would be reinforced over the course of an entire experimental session; thus, the lights were analogous to a drug cue in drug-discrimination situations. In test (generalization) sessions of one FR in duration, the percentage of light on the center key was varied from 0 to 100%. During these sessions, saline, lysergic acid diethylamide (LSD; 0.04-0.20 mg/kg) and morphine (3.75 mg/kg) produced orderly, log-linear light generalization gradients, but only LSD shifted the gradient to the right (by approximately 50%). These results demonstrate the potential value of the method for assessing the effects of drugs on both exteroceptive (light) and interoceptive (drug) stimulus control. The method has the additional advantage that the effects of drugs on such control (i.e., on stimulus generalization) are relatively unaffected by corresponding effects on response control (e.g., rate of responding).

Stereotyped behavior affected by peripheral and intracerebroventricular apomorphine administration in pigeons.

In pigeons, peripheral injection of apomorphine HCl (1.5 mg) produced a rapid pecking response while intracerebroventricular administration of the drug (60 micrograms) was ineffective in this respect. Both peripheral and to a larger extent central treatment with apomorphine stimulated another activity, that is headshaking. The frequency of other behavioral patterns was either decreased (preening) or unaffected (yawning, stretching) following both treatments. Together with previous studies, these data suggest that (a) apomorphine stimulates pecking in pigeons by activating dopaminergic mechanisms lying in brain areas situated away from the ventricles; (b) dopaminergic mechanisms situated in periventricular regions may take part in the control of some patterns, e.g. headshaking, and (c) other activities do not appear to depend directly on these mechanisms.

TRACE AUTOSHAPING: ACQUISITION, MAINTENANCE, AND PATH DEPENDENCE AT LONG TRACE INTERVALS

The pigeon's tendency to acquire and maintain signal-directed key pecking under a trace conditioning procedure was parametrically examined. In Experiment 1, the percentage of CS trials with a key peck response was a decreasing function of the trace interval for separate groups of pigeons. The majority of subjects acquired signal-directed key pecking with trace intervals as long as 36 sec. In Experiment 2, differential maintenance of key pecking occurred across trace intervals in a within-subject procedure. Maintenance of key pecking at 36- and 60-sec trace intervals was path dependent in that responding depended on the subject's performance under the preceding trace interval.

Control of pigeons’ keypecking topography by a schedule of alternating food and water reward

Food- and water-deprived pigeons keypecked for food or water reinforcement on alternate trials. Under one condition, explicit stimuli on the key provided information about the trial outcome; under another condition, only the alternation schedule provided this information. Latency and/or response rate differences between food- and water-rewarded trials emerged during both conditions. Response topography also differed on food- and water-rewarded trials. These differences, as revealed by duration and force measurements of the keypeck and by human ratings of the pecking responses as being water- or food-related, were anticipatory in nature. These results not only extend previous work on reward alternation and reward-specific response topographies, but also have implications for theories of animal memory. In particular, these results are amenable to memory models that assume that an animal “codes” information that later must be recalled.

Operant Response Pattern for Chicks in Imprinting and its Relation to their Following Responses

It was investigated whether newly hatched chicks emitted some operant responses in bursts immediately after the presentation of a moving imprinting stimulus with sounds, a reinforcer which like brain stimulation reward. And the relation of these responses to the following response was examined and discussed.After three 15-min imprinting sessions over the first 3 days posthatch, three chicks selected according to the level of the following response time were trained to peck either of two colored keys (red & green) for the imprinting stimulus.In subsequent daily key peck training sessions (5-25 Days posthatch), reinforced peck responses tended to occur in bursts as seen in ducklings. Even a chick of poor following response time acquired and maintained such a response pattern. The probability of initiating a key peck response decreased as a function of the interresponse time.These findings imply that a reduction of following response in imprinting may be caused by the occurence of some operant responses acquired in process of ontogenical development and that the temporal pattern of operant responses in chick's imprinting reflects a priming effect.

The temporal pattern of attachment behavior in the context of imprinting

Newly hatched ducklings (Anas platyrhynchos domesticus) were trained to peck a pole for brief presentations of a moving imprinting stimulus, a reinforcer which like brain stimulation reward, engenders priming aftereffects. In subsequent daily 2-hr sessions reinforced peck responses tended to occur in bursts. The length of a burst was independent of the length of temporally adjacent bursts and interburst intervals. The probability of initiating a burst decreased as a function of the time since the last burst. The probability of continuing a current burst increased as responding within the burst proceeded. These findings imply that the temporal pattern of attachment behavior reflects a priming effect superimposed upon a low, but non-zero probability of responding. As such the data are consistent with the view that attachment represents an addiction-like process and that it may be mediated by the opiate-like peptides.

An investigation of peak shift and behavioral contrast for autoshaped and operant behavior.

Instrumental treadle press and nonreinforced key peck responses were monitored during discrimination training and generalization testing in pigeons on positive and negative reinforcement schedules. In Experiment 1, six pigeons pressed a treadle for food on a multiple variable-interval extinction schedule. In Experiment 2, three pigeons pressed a treadle to avoid shock on a multiple free-operant avoidance extinction schedule. Different color keylights signaled S+ and S- components. Some positive behavioral contrast occurred during discrimination training, but the effect was small. Pecking occurred to the S+ keylight in Experiment 1 but not in Experiment 2. On stimulus generalization tests, all subjects displayed a positive peak shift when pressing the treadle for food or to avoid shock. However, peak shift was not found for nonreinforced "autopecks" on the stimulus key, although an area shift was observed in Experiment 1. This is the first demonstration of peak shift for pigeons pressing treadles and the only reliable demonstration of peak shift when negative reinforcement maintained responding. These results, in combination with previous demonstrations of peak shift for rats pressing levers and pigeons pecking keys, indicate that peak shift is a general by-product of operant discrimination learning, since it occurs across a variety of the organisms, responses, and reinforcers.

Retroactive amnesia induced in chicks by the proline analog L-baikiain, without EEG seizures or depression

L-Proline induces retroactive amnesia without causing brain seizures or isoelectric activity. L-Baikiain, a proline analog containing one more carbon atom in the ring and a double-bond, has similar amnestic effects but at one-fourth the dose. Chicks were injected intracerebrally with 5 μl/hemisphere of 150 mM L-biakiain, L-proline, or D-proline, 1 min after one-trial training to suppress the spontaneous peck response to a 3-mm stainless steel bead. The results demonstrate that L-baikiain is an effective retroactive amnestic agent compared to D-proline controls. The amnestic effect induced by 1.5 μmols of L-baikiain is comparable to that found with 6.0 μmols of L-proline in previous experiments. Electrophysiological recording of multiple-unit activity and raw integrated EEG activity showed no seizure spiking or isoelectric activity. No reliable differences in EEG and multiple-unit activity were observed betwen L-baikiain and D-proline injections. We conclude that L-baikiain is approximately 4x more potent than L-proline as an amnestic agent and that both compounds are effective at non-lethal doses which cause no marked electrophysiological changes.

MATCHING WITH A KEY PECK RESPONSE IN CONCURRENT NEGATIVE REINFORCEMENT SCHEDULES1

In the absence of responding, pigeons were shocked under a variable-time schedule. Responses on either of two keys occasionally produced one minute of shock-free time. That is, pigeons' key pecks were reinforced with shock-free time under concurrent variable-interval schedules. The relative frequency of access to the one-minute shock-free periods was systematically manipulated. Pigeons tended to match both relative response rate and proportion of time spent on each key to the relative frequency of the shock-free periods. A best-fit linear regression equation accounted for over 95% of the variance in both relative response rate and time allocation. The data paralleled closely the results of concurrent schedules of positive reinforcement. These findings are consistent with a description of reinforcement as a transition to a higher-valued situation and suggest that common laws govern choice for both positive and negative reinforcement.

Affiliation, xenophobia, and the behavioral organization of the young domestic chicken

Evidence was reviewed that the social mediation of responses (variously labeled contagion, imitation, or synchrony, among other terms) is an important factor in the behavioral organization of young precocial birds, and the question was raised as to whether or not specific social affiliations are a prerequisite for such an influence. Experiments were conducted with young chickens to determine if there was more matching of responses among companions (cagemates) than among strangers (noncagemates). In the first study, groups of test naive birds were observed, while, in the second study, naive subjects were confronted with conspecific models that had been prepared to exhibit high rates of particular responses (food pecking or tonic immobility). While there was certain evidence that the chickens were disturbed by the presence of strangers (that is, showed a kind of xenophobia), there was as much matching of peck responses observed in combinations of strangers as was observed in combinations of companions. Correlation coefficients expressing matching of food pecking were positive, large, and highly significant under all social conditions. However, social mediation of the immobility reaction was not consistently obtained. The results were discussed in terms of requirements for a theory of social motivation in this species that takes into account both gregarious and xenophobic tendencies.

Ontogeny of the peck response in chicks: Age dependence and target dependence

The spontaneous peck response of neonate chicks ( Gallus gallus ) has been criticized as unsuitable for creating a general model of memory because of evidence that the response is limited to the first 3 days posthatch. The evidence is invalid because of the use of an inappropriate peck target. With appropriate peck targets, the spontaneous peck response remains high for at least 8 days posthatch, and the trained peck response remains high for at least 11 days posthatch.

Classical conditioning of the rabbit's nictitating membrane response under fixed and mixed CS-US intervals

The rabbit's nictitating membrane response was classically conditioned to a tone CS, followed by an electric shock US, at two randomly alternating CS-US interstimulus intervals (ISIs). Different groups were exposed to different proportions of 200- and 700-msec ISIs. The study revealed: (a) CR percentage was a direct function of the proportion of 200-msec ISIs; (b) trials to the first test-trial CR were an inverse function of the proportion of 200-msec ISIs; (c) CR onset latencies decreased over training; (d) CR peak latencies coincided with the temporal loci of the US; and (e) groups exposed to both ISIs acquired double-peaked CRs. Moreover, the amplitudes of nictitating membrane responses in the present experiment paralleled certain quantitative aspects of the free operant key peck response rates of pigeons trained under two mixed inter-reinforcement intervals. The results were discussed with respect to the micromolar response shaping and macromolecular CS-trace accounts of classical conditioning.

Postnatal behavioral alterations resulting from prenatal administration of dl-alphamethylparatyrosine.

We have previously reported that injection of dl-alphamethylparatyrosine methylester (AMPT) into the yolk sac of fertilized chicken eggs prior to incubation results in dose-related increases in the specific activity of tyrosine hydroxylase (TH) at 29 days postnatally. We now report that injection of 10.0 and 33.3 mg/kg of AMPT prior to incubation results in dose-related increases in acquisition rates of 2 operant responses. Between 1 and 3 weeks of postnatal age, we observed a dose-related decrease in latency to perform a detour response and, at 55-60 days of postnatal age, an increased rate of acquisition of a key peck response in an autoshaping paradigm. We could not discern any significant alteration in several measures of unconditioned behaviors in an open field situation at 3 weeks of postnatal age. Our data support the contention that early catecholamine (CA) depletion can produce long-term alterations in postnatal behavior.

The ontogeny of the peck response in Gallus gallus: constraints on a model system of memory

This study examined the availability of the spontaneous peck response in white leghorn cockerels and observed that this response is limited to the first few days following hatching. These data suggest serious constraints for the utility of this paradigm in the creation of a general model of memory. Rather, the appeal of this paradigm pertains to the special features and limits inherent in the spontaneous peck response that have been described in this paper.

PERSISTENCE OF ACQUIRED BEHAVIORAL CONTROL IN THE CONTEXT OF IMPRINTING1

Newly hatched Khaki Campbell ducklings (Anas platyrhynchos domesticus) were exposed to a moving object that immediately suppressed distress vocalizations occurring in a novel environment. The static visual and auditory features of this object acquired the ability to suppress distress vocalizations after eight 20-min sessions of exposure to the object in motion. The acquired suppressive properties of these features were found to persist throughout thirty 20-min sessions given over 10 days. During these sessions, the ducklings were continually exposed to the static features in the absence of visual movement. In a second experiment, the ability of these features in the absence of visual movement. In a second experiment, the ability of these features to serve as reinforcement for a pecking response was shown to persist for up to 56 hr. In one duckling, presentations of the static visual features did not maintain pecking behavior. However, it was shown that pecking responses could be re-instated in this duckling by introducing novel stimuli to the environment.