Biomedical subjects

Russell M Church

Publications and source records attributed to Russell M Church.

9 recordsLinked to original sources

PubMed2006

Effects of repeated acquisitions and extinctions on response rate and pattern.

The procedure developed by R. A. Rescorla (2002) was used to study the effects of repeated acquisitions and extinctions of head entry responses into a food cup by rats. In each of 4 20-session phases, food was delivered at the end of particular 30-s auditory and visual stimuli, but not at the end of different 30-s auditory and visual stimuli. Based on response rates to individual stimuli and compound stimuli, the increase in response rate in acquisition occurred more rapidly than the decrease in extinction. Acquisition, but not extinction, occurred faster after successive transitions between acquisition and extinction. Temporal gradients of responding developed during acquisition and remained during extinction. Conclusions based on mean response rate, temporal gradients, and transfer tests were consistent.

Acoustic Stimulation↗

PubMed2006

The pattern of responding after extensive extinction.

Extensive extinction greatly reduces response rate and increases the relative frequency of short interresponse times, but does not affect temporal learning or operant response rate. In each of two experiments, 24 rats were trained in a multiple cued interval procedure with three stimuli (noise, light, and clicker) at three intervals (30, 60, and 120 sec). In Experiment 1, after 50 sessions of extinction, response rate decreased from about 25 to 0.5 responses/min, but temporal discriminations were maintained and the initial response gradients in reacquisition had a pattern that corresponded with the original (rather than current) training conditions. In Experiment 2, these results were replicated and extended by examination of the effect of stimulus duration on response patterns during extinction, but its lack of effect on reacquisition. The similarity of the initial performance in reacquisition to the asymptotic performance in acquisition was presumably due to the similarity of context. The individual subject data may be downloaded from www.psychonomic.org/archive.

Animals↗

PubMed2005

How rats combine temporal cues.

The procedures for classical and operant conditioning, and for many timing procedures, involve the delivery of reinforcers that may be related to the time of previous reinforcers and responses, and to the time of onsets and terminations of stimuli. The behavior resulting from such procedures can be described as bouts of responding that occur in some pattern at some rate. A packet theory of timing and conditioning is described that accounts for such behavior under a wide range of procedures. Applications include the food searching by rats in Skinner boxes under conditions of fixed and random reinforcement, brief and sustained stimuli, and several response-food contingencies. The approach is used to describe how multiple cues from reinforcers and stimuli combine to determine the rate and pattern of response bouts.

Animals↗

PubMed2005

Empirical tests of "Take-the-Best" with non-human subjects.

The fast and frugal heuristics of ABC and rules of thumb of behavioural biologists represent strategies that humans and other animals might use to make decisions under time constraints and with a minimum of information. If experimental psychologists could demonstrate use of simple heuristics by non-humans in experimental settings, quantitative and empirical evaluation of those heuristics would benefit from additional formal, controlled avenues of study.

Algorithms↗

PubMed2005

A Turing test of a timing theory.

A quantitative theory of timing or conditioning can be evaluated with a Turing test in which the behavioral results of an experiment can be compared with the predicted results from the theory. An example is described based upon an experiment in which 12 rats were trained on three fixed-interval schedules of reinforcement, and a simulation of the predicted results from a packet theory of timing. An objective classification rule was used to determine whether a sample from the data or a sample from the theory was more similar to another sample from the theory. With an ideal theory, the expected probability of a correct classification would be 0.5. The observed probability of a correct classification was 0.6, which was slightly, but reliably, greater than 0.5. A Turing test provides a graded metric for the evaluation of a quantitative theory.

Animals↗

PubMed2005

Dynamics of temporal discrimination.

The purpose of this research was to describe and explain the acquisition of temporal discriminations, transitions from one temporal interval to another, and asymptotic performance of stimulus and temporal discriminations. Rats were trained on a multiple cued interval (MCI) procedure with a head entry response on three signaled fixed-interval schedules of reinforcement (30, 60, and 120 sec). They readily learned the three temporal discriminations, whether they were presented simultaneously or successively, and they rapidly adjusted their performance to new intervals when the intermediate interval was varied daily. Although exponential functions provided good descriptions of many measures of temporal discrimination, different parameter values were required for each measure. The addition of a linear operator to a packet theory of timing with a single set of parameters provided a quantitative process model that fit many measures of the dynamics of temporal discrimination.

Animals↗

PubMed2004

Temporal learning in random control procedures.

Experiments 1 and 2 delivered conditioned stimuli (CSs) at random times and unconditioned stimuli (USs) at either fixed (Experiment 1) or random (Experiment 2) intervals. In Experiment 3, CS duration was manipulated, and US deliveries occurred at random during the background. In all 3 experiments, the mean rate of responding (head entries into the food cup) in the background was determined by the mean US-US interval, and the mean rate during the CS was a linear combination of responding controlled by the mean US-US and mean CS onset-US intervals; the pattern of responding in time was determined by the interval distribution form (fixed or random). An event-based timing account, Packet theory, provided an explanation of the results.

Animals↗

PubMed2004

Measures of temporal discrimination in fixed-interval performance: a case study in archiving data.

The primary data of many experimental studies of animal learning and performance consist of the times at which stimuli and reinforcers were delivered, and the times at which responses occurred. The articles based on most of these studies report selected data, either from some sessions or some animals, or summary measures of the animals' behavior. The primary data are sufficient to produce any of the selected and summary measures, but the selected and summarized data cannot produce many of the measures used in other experimental reports. It is now feasible to archive the primary data from animal behavior experiments so that they are accessible for others to perform secondary analysis. The value of such secondary analysis of archived data is described with a case study in which rats were trained on three fixed-interval schedules of reinforcement. The full data set may be downloaded from www.psychonomic.org/archive/.

Animals↗

PubMed2002

Data archiving for animal cognition research: report of an NIMH workshop.

In July 2001, the National Institute of Mental Health sponsored a workshop titled "Data Archiving for Animal Cognition Research." Participants included scientists as well as experts in archiving, publishing, policy, and law. As is described in this report, the workshop resulted in a set of conclusions and recommendations concerning (A) the impact of data archiving on research, (B) how to incorporate data archiving into research practice, (C) contents of data archives, (D) technical and archival standards, and (E) organizational, financing, and policy issues. The animal cognition research community is encouraged to begin now to establish archives, deposit data and related materials, and make use of archived materials in new scientific projects.

Animals↗