TIME‐ALLOCATION, MATCHING, AND CONTRAST 1

Self Cite

137

Three pigeons pecked for food in an experiment in which each trial consisted of two phases. The first phase consisted of a pattern of three successively illuminated, randomly selected left or right keys. A subject was required to peck each of the lighted keys as they appeared. Thus, in the first phase, a subject emitted a pattern of three left-or right-key pecks. Over trials, all eight possible patterns appeared. A time interval separated the first phase from the second phase, which began with presentation of a randomly selected one of three cues. A reinforcer was delivered in the second phase if a subject pecked the side key that had appeared in the first phase in an ordinal position corresponding to the cue presented in the second phase. That is, the three cues probed a pigeon's memory for the side key it had pecked first, second, or third, in the first phase of a trial. The results show that a pigeon can remember for more than 4 sec the order in which it has just seen and pecked two lighted keys: a pigeon can remember the temporal organization or pattern of events in its recent environment. Consequently, the functional stimulus present when a reinforcer is delivered may include a subject's short-term memory for the temporal organization of recent events, such as the pattern of its own recent behavior. This possibility is consistent with a molecular analysis of operant behavior focusing on local patterns of behavior.

Section: Proceduttresupporting

confidence: 79%

SHORT‐TERM MEMORY IN THE PIGEON: RELATIVE RECENCY¹

Shimp

1976

Self Cite

137

“…Mean response rate then is a byproduct of these patterns. The patterns required by the reinforcement contingency are the behavioral units in such schedules, and mean response rate is derived from the patterns: mean response rate does not reveal the controlling relationships and does not measure the strength of a key-pecking or lever-pressing operant (see Shimp, 1974;Shimp and Hawkes, 1974).…”

Section: Discussionmentioning

confidence: 99%

REINFORCEMENT OF BEHAVIORAL PATTERNS: SHAPING A SCALLOP¹

Hawkes

Shimp

1975

Self Cite

101

Temporal patterns of key pecking by pigeons were shaped by a schedule in which the delivery of food was contingent upon a measure of the overall extent to which the temporal pattern of behavior within a 5-sec trial conformed to a required pattern. This pattern approximated a constant rate of change in the rate of key pecking throughout the 5-sec trial. In comparison with behavior maintained by a classical fixed-interval 5-sec schedule, the new schedule controlled a better approximation to a "scallop" within individual trials and greatly reduced intersubject variability. These results are consistent with the view that the delivery of a reinforcer after a behavioral pattern a few seconds in duration may strengthen the entire pattern as a unit, or operant. The response topography contiguous with reinforcement may be a negligible fraction of the strengthened operant. One implication of this view is that mean response rate for such brief responses as key pecks and lever presses is a byproduct of whatever patterns are strengthened, and generally will not reveal fundamental controlling relationships, whenever a reinforcer is not contiguous with all the behavior on which it is contingent.

“…If so, response-rate invariance should not occur when the COD does not produce the postchangeover response bursts, nor should it occur with changeover contingencies that do not produce such bursting. The possible importance for response-rate invariance of such "local factors" has been noted recently (Catania, 1972;Shimp and Hawkes, 1974). EXPERIMENT I Experiment I followed Catania's basic procedure of comparing response rates on concurrent schedules with and without restriction on changeovers.…”

mentioning

confidence: 99%

RESPONSE‐RATE INVARIANCE IN CONCURRENT SCHEDULES: EFFECTS OF DIFFERENT CHANGEOVER CONTINGENCIES¹

Guilkey

Shull

Brownstein

1975

In a two-key chamber, one key (the food key) was either red or green with different variable-interval schedules operating concurrently in each color and a second key (the changeover key) served to change the food-key color. Three pigeons were trained with either a 2-sec changeover delay or a 0-sec changeover delay and three birds with a fixed-ratio 2 on the changeover key instead of a changeover delay. The proportion of time spent in red approximated the proportion of reinforcers delivered in red for all birds. When the procedure was changed so that reinforcers were signalled in the green schedule, rates of reinforcement were unaltered, but the pigeons spent virtually the whole session in red. Changeovers to green were allowed only when a reinforcer was assigned by the schedule associated with green. For all pigeons with the fixed-ratio requirement on the changeover key or with a 0-sec changeover delay, the overall rate of red-key responses was higher during the signalling condition than during unsignalled, or baseline, condition. The present data question the generality of previous reports that the rate of one response is independent of the amount of time allocated to the alternative response.