DELAYED DISCRIMINATION AND DELAYED MATCHING IN PIGEONS 1

Separate groups of rats were trained and tested on asymmetrically and symmetrically reinforced successive delayed matching-to-sample (DMTS) or delayed discrimination (DD) tasks in Experiment 1. Each rat received training and testing on symmetrically reinforced DMTS and DD tasks in Experiment 2. The only difference between each task was that the rats had to respond correctly to a light or tone test stimulus, S2' if it matched a light or tone sample stimulus, S" in DMTS, but could respond to either S2 if S, had been a particular stimulus in DD. Only correct leverpresses were reinforced in the asymmetrically reinforced version of each task. Both correct presses and correct omissions were reinforced in the symmetrically reinforced version of each task. Response biases to leverpress during tests for delayed responding to S. were reduced in both symmetrically reinforced tasks, but only in the DD task did such contingencies produce consistently poorer performance in responding to either S. in Experiment 1. Declines in accuracy of performance that occurred in both experiments were greater to the visual than to the auditory S, only in the DMTS tasks with increased intervals between S, and S2. A third experiment, in which rats had to respond to S2 if it matched S. (DMTS) or if S2 mismatched S. (DMmTS), was carried out. Modality of S. similarly affected accuracy of delayed responding in each task, as in the first two experiments. Methodological and theoretical implications of these results are discussed in terms of Honig and Thompson's (1982) dual-process theory of working memory.Honig and Thompson (1982) distinguish between retrospection, memory of a previous stimulus, and prospection, retention of an instruction for future responding to the previous stimulus, in short-term memory of nonhuman animals.

Section: Discussioncontrasting

confidence: 99%

mentioning

confidence: 97%

Retrospective and prospective short-term memory in delayed response tasks in rats

Cohen

Galgan

Fuerst

1986

“…Additionally, the procedure permitted the dolphin to potentially "bridge" the delay interval following sound A or B by orienting toward the correct paddle or by using other overt mediational cues (Fletcher, 1965). Direct delayed discriminations have been studied in the pigeon (Smith, 1967). Monkeys have also been trained to make a spatial response conditional upon an auditory discriminative stimulus (Dewson & Cowey, 1969), but delay effects were not examined.…”

Section: Resultsmentioning

confidence: 99%

Auditory delayed discriminations by the dolphin: Nonequivalence with delayed-matching performance

Thompson

Herman

1981

Working memory in a bottlenosed dolphin was tested in both indirect and direct auditory delayed-discrimination tasks in which a correct spatial response was conditional upon the nature of a preceding sound. In the indirect task, either one of two possible sounds was briefly presented. After a prescribed delay, the dolphin was cued to go either to a left-hand or right-hand paddle pair, Responses to the outer paddle of a pair were rewarded following sound A, and responses to the inner paddle of a pair were rewarded after sound B. In the direct delayeddiscrimination task, only one paddle pair was used in each session. In both tasks, the delay interval between the discriminative sound stimulus and the opportunity for a spatial response was progressively increased over sessions until the animal failed to meet a specified performance criterion or self-terminated a session. Delay limits of about 30 and 60 sec were obtained in the indirect and direct tasks, respectively. The increase in delay limit in the latter task was attributable to the use of an overt mediatio~response during the longer delays. In both cases, however, the obtained delay limits fell considerably short of the 2-to 3-min limits obtained in auditory delayed-matching studies using the same test sounds and the same subject. The task differences indicate that working memory functions cannot depend upon memory of the predelay stimulus alone. but must be determined in part by additional processes.

“…In studies of delayed matching-to-sample (DMTS), the short-term memory of dolphins (Herman, 1975;Herman & Gordon, 1974;Herman et al, 1989) and ofnonhuman primates (D ' Amato, 1973;D' Amato & Worsham, 1972;Jarrard & Moise, 1971) remains above chance levels after delays of 1 min or longer after removal of the sarnple. In contrast, memory for a sampie stimulus in pigeons may fall to chance levels after postsampie delays of 10 sec or less (see, e.g., Berryman, Cumming, & Nevin, 1963;D'Amato & Salmon, 1984;Grant, 1976;Roberts, 1972;Smith, 1967). Only in an extreme case of over 17,000 DMTS training trials and the use of relatively long sampleexposure durations has short-term memory of the pigeon been extended to as long as 1 min (Grant, 1981).…”

Section: Uniuersity Of Hawaii Honolulu Hawaiimentioning

confidence: 99%

Generalization of visual matching and delayed matching by a California sea lion (Zalophus californianus)

Pack

Herman

Roitblat

1991

Only a limited number of species have been found capable of generalized matching-to-sample (MTS) after exposure to relatively few training exemplars. We trained a juvenile, experimentally naive California sea lion (Zalophus californianus) in MTS, using a pair of three-dimensional objects as samples. Successful matehing to a criterion of 90% correct or better over 2 successive sessions was attained in 12 sessions (269 trials and 70 errors), Two subsequent "partial" transfer tests, in which each of the two training objects was paired with a novel test object, and four additional transfer tests, a11 with novel objects, were presented fo11owing training. An 80% performance criterion over 2 successive sessions was reached, or closely approximated, in from 2 to 4 transfer sessions for a11 transfer tests; errors to criterion tended to be reduced across the successive novel transfer tests and were as few as five during the final two tests; and performance on the first 48 trials of the last two novel transfers was not significantly different from a nearceiling level baseline performance measure. Neophobie responses of the sea lion to new objects precluded an unbiased evaluation of immediate (Trial 1) transfer. The sea Iion's short-term memory for sample objects was also measured. Matching performance was maintained at a level of 78% correct responses or better for delays through to 45 sec after removal of the sample object. At a 58-sec delay, the longest tested, performance declined to 69% correct responses. These retention levels are only somewhat below levels reported for dolphins and nonhuman primates tested on visual delayed MTS, but they are above levels typically reported for pigeon subjects.A fundamental issue in comparative cognition is the ability of animals to form broad, general concepts about the relationships among objects or other types of stimuli.Although this ability may be tested within many different paradigms (see Roitblat, 1987, for a review), tasks that direct the animal to detect and report on the identity relationship have been particularly useful. These include same/different tasks, in which the animal judges whether or not two items are identical (e.g., Wright, 1971), as well as matching-to-samp1e (MTS) tasks (e.g., D'Arnato, 1973). There are several forms of the MTS task (cf. D' Amato & Worsham, 1974;Herman & Thompson, 1982;Roitblat & Scopatz, 1983); in this paper, we will 37report on visual identity MTS. This task is typified by three steps: (1) the exposure, usually brief, of a sample stimulus, followed by the stimulus' removal; (2) the interposition of a delay period, ranging from 0 sec upwards; and (3) the exposure oftwo or more altematives, one of which physically matches the sample. The animal is rewarded for choosing the matehing alternative.To measure the development of a concept of identity, the experimenter presents new stimulus items after MTS training has been completed with a limited number of items; the experimenter then tests whether or not the subject can transfer the identity r...