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Biomedical subjects

D M Rumbaugh

Publications and source records attributed to D M Rumbaugh.

At least 37 records · Page 2Linked to original sources
PubMed1990

Effects of competition on video-task performance in monkeys (Macaca mulatta).

The effects of competition on performance of a video-formatted task were examined in a series of experiments. Two rhesus monkeys (Macaca mulatta) were trained to manipulate a joystick to shoot at moving targets on a computer screen. The task was made competitive by requiring both animals to shoot at the same target and by rewarding only the animal that hit the target first each trial. The competitive task produced a significant and robust speed-accuracy trade-off in performance. The monkeys hit the target in significantly less time on contested than on uncontested trials. However, they required significantly more shots to hit the target on contested trials in relation to uncontested trials. This effect was unchanged when various schedules of reinforcement were introduced in the uncontested trials. This supports the influence of competition qua competition on performance, a point further bolstered by other findings of of behavioral contrast presented here.

Animals↗
PubMed1990

The NASA/LRC Computerized Test System.

A new testing package, including apparatus and tasks, is described for the study of behavior of a variety of species in a variety of experiments. The package is described with respect to the kinds of comparative psychological investigations for which it is well suited. The preliminary data generated within this new testing paradigm demonstrate that the NASA/LRC Computerized Test System provides a flexible yet powerful environment for the investigation of behavioral and psychological processes.

Animals↗
PubMed1989

Lana chimpanzee learns to count by "NUMATH": a summary of a videotaped experimental report.

This paper summarizes a videotaped presentation (Rumbaugh, Savage-Rumbaugh, Hopkins, Washburn, & Runfeldt, 1987) of computerized training programs whereby an adult female chimpanzee, Lana (Pan troglodytes), learned to use a joystick to remove from a screen the number of boxes appropriate to the value of a randomly selected Arabic numeral 1, 2, or 3. Initial training provided a variety of cues, both numeric and otherwise, to support correct performance. Across software programs, all cues other than numeric ones were deleted. In the final test, Lana was correct on over 80% of trials in which there was no residual feedback of intratrial events and where only her memory of those events could provide the cue to indicate that she had removed boxes in accordance with the value of the target numbers and should terminate the trial. The tape is narrated and consists of video recordings of Lana's performance on each software program.

Animals↗
PubMed1989

Rhesus monkeys (Macaca mulatta), video tasks, and implications for stimulus-response spatial contiguity.

Recent reports (Iwai, Yaginuma, & Mishkin, 1986; Yaginuma & Iwai, 1986) have supported the earlier conclusion by Meyer, Treichler, and Meyer (1965) and by Stollnitz (1965) that the efficiency of primate learning is compromised to the degree that there is spatial discontiguity between discriminanda and the locus of response. The research reported in this article calls for a reconsideration of this conclusion. Two rhesus monkeys (Macaca mulatta) easily mastered precise control of a joystick to respond to a variety of computer-generated targets despite the fact that the joystick was located 9 to 18 cm from the video screen. We hold that stimulus-response contiguity is a significant parameter of learning only to the degree that the monkey visually attends to the directional movements of its hand in order to displace discriminanda as in the Wisconsin General Test Apparatus. If, instead, attention is focused on the effects of the hand's movement rather than on the hand itself, stimulus-response contiguity is no longer a primary parameter of learning. The implications of this work for mirror-guided studies are discussed.

Animals↗
PubMed1989

Note on hand use in the manipulation of joysticks by rhesus monkeys (Macaca mulatta) and chimpanzees (Pan troglodytes).

In a recent article MacNeilage, Studdert-Kennedy, and Lindblom (1987) proposed that nonhuman primate handedness may be contingent on the specific task requirements with visual-spatial tasks yielding left-hand preferences and fine motor tasks producing right-hand preferences. This study reports hand preferences in the manipulation of joysticks by 2 rhesus monkeys (Macaca mulatta) and 3 chimpanzees (Pan troglodytes). Reach data were also collected on these same subjects and served as a basis for comparison with preference data for manipulation of the joystick. The data indicated that all 5 subjects demonstrated significant right-hand preferences in manipulating the joystick. In contrast, no significant hand preferences were found for the reach data. Reaction time data also indicated that the right hand could perform a perceptual-motor task better than the left hand in all 5 subjects. Overall, the data indicate that reach tasks may not be sensitive enough measures to produce reliable hand preferences, whereas tasks that assess fine motor control produce significant hand preferences.

Animals↗
PubMed1989

Automation of learning-set testing: the video-task paradigm.

Researchers interested in studying discrimination learning in primates have typically utilized variations in the Wisconsin General Test Apparatus (WGTA). In the present experiment, a new testing apparatus for the study of primate learning is proposed. In the video-task paradigm, rhesus monkeys (Macaca mulatta) respond to computer-generated stimuli by manipulating a joystick. Using this apparatus, discrimination learning-set data for 2 monkeys were obtained. Performance on Trial 2 exceeded 80% within 200 discrimination learning problems. These data illustrate the utility of the video-task paradigm in comparative research. Additionally, the efficient learning and rich data that were characteristic of this study suggest several advantages of the present testing paradigm over traditional WGTA testing.

Animals↗
PubMed1989

Video-task assessment of learning and memory in macaques (Macaca mulatta): effects of stimulus movement on performance.

Effects of stimulus movement on learning, transfer, matching, and short-term memory performance were assessed with 2 monkeys using a video-task paradigm in which the animals responded to computer-generated images by manipulating a joystick. Performance on tests of learning set, transfer index, matching to sample, and delayed matching to sample in the video-task paradigm was comparable to that obtained in previous investigations using the Wisconsin General Testing Apparatus. Additionally, learning, transfer, and matching were reliably and significantly better when the stimuli or discriminanda moved than when the stimuli were stationary. External manipulations such as stimulus movement may increase attention to the demands of a task, which in turn should increase the efficiency of learning. These findings have implications for the investigation of learning in other populations, as well as for the application of the video-task paradigm to comparative study.

Animals↗
PubMed1988

Addendum to "Summation in the chimpanzee (Pan troglodytes)".

Rumbaugh, Savage-Rumbaugh, and Hegel (1987) reported that two chimpanzees (Pan troglodytes) could select, with better than 90% accuracy, the greater of two paired quantities of chocolate chips. In that study, no one quantity of chocolates (from 0 through 5) was used in both pairs on a given trial. We investigated the effect of having one quantity in common (CQ) in both pairs. Whether the other quantities (OQs) of chocolates were both less than or greater than the CQ, summation still occurred. Accuracy was primarily a function of the ratios of sums to be differentiated. This finding substantiated the earlier conclusion that summation was based on both quantities of each pair and not on some simpler process such as the avoidance of the tray with the smallest single amount or selection of the tray with the single largest amount.

Animals↗
PubMed1987

Summation in the chimpanzee (Pan troglodytes).

In this research, we asked whether 2 chimpanzee (Pan troglodytes) subjects could reliably sum across pairs of quantities to select the greater total. Subjects were allowed to choose between two trays of chocolates. Each tray contained two food wells. To select the tray containing the greater number of chocolates, it was necessary to sum the contents of the food wells on each tray. In experiments where food wells contained from zero to four chocolates, the chimpanzees chose the greater value of the summed wells on more than 90% of the trials. In the final experiment, the maximum number of chocolates assigned to a food well was increased to five. Choice of the tray containing the greater sum still remained above 90%. In all experiments, subjects reliably chose the greater sum, even though on many trials a food well on the "incorrect" tray held more chocolates than either single well on the "correct" tray. It was concluded that without any known ability to count, these chimpanzees used some process of summation to combine spatially separated quantities. Speculation regarding the basis for summation includes consideration of perceptual fusion of pairs of quantities and subitization.

Animals↗
PubMed1985

The capacity of animals to acquire language: do species differences have anything to say to us?

Following the Gardners' discovery that an ape named Washoe could learn to produce and combine a number of hand movements similar to those used by deaf human beings, a variety of 'ape-language projects' sprang up. Some projects used different symbol systems, others used different training techniques, and others used different species of apes. While debate still rages regarding the appropriate way to interpret the symbolic productions of apes, three species of great apes (gorilla, orangutan, and chimpanzee) have now been credited with this capacity while no lesser apes or monkeys have been reported, at present, to have acquired such communicative skills. Among all of the claims made for the various animal species, the philosophers have entered the fray attempting to define the essence of what it is about language that makes it 'human'. This paper will compare and contrast the above positions to arrive at behavioural definitions of symbolic usage that can be applied across species. It will then present new data on a fourth ape species Pan paniscus which is proving to be the first non-human species to acquire symbolic skills in a spontaneous manner.

Animals↗
PubMed1985

Language learning in two species of apes.

A 4 year old pygmy chimpanzee (Pan paniscus) has spontaneously begun to use symbols for the purpose of communicating. Other apes have required training before they began to use symbols fluently. By contrast, this pygmy chimpanzee has begun to learn and appropriately employ graphic symbols simply as the result of exposure to human models. He has also spontaneously demonstrated an ability to comprehend many spoken English words and his multi-word utterances consistently provide more information than his single-word utterances.

Animal Communication↗
PubMed1985

Discrimination of lexigrams and traditional orthography by nonspeaking severely mentally retarded persons.

The discriminability of two abstract symbol sets by nonspeaking severely mentally retarded persons was investigated. Symbol-naive and symbol-experienced subjects' responses to traditional orthographic letters and lexigram elements were compared in a match-to-sample task. Overall, subjects' responses to lexigrams were more accurate and faster than were their responses to traditional orthography. Responses to less complex combinations of elements or letters, however, were more accurate and faster than were responses to more complex combinations. On the basis of these data, we conclude that the perceptual features of lexigrams are easier to discriminate than those of traditional orthographic letters.

Adult↗
PubMed1985

Retention of symbolic communications skills by severely mentally retarded persons.

The nonspeech symbol vocabularies of five severely mentally retarded persons were assessed 18 months after the completion of a longitudinal computer-keyboard symbol acquisition study. These individuals retained a mean of 83% of their comprehension vocabularies and 70% of their production vocabularies without systematic maintenance teaching on the learned symbols. Interviews with special-education and living unit staff members corroborated this result and described the ways in which the subjects used their conversation boards in their everyday environment.

Adolescent↗
PubMed1984

Facilitating visual discrimination learning of moderately and severely mentally retarded children through illumination of stimuli.

The effectiveness of illuminating the positive stimulus after a correct response in visual discrimination training of moderately and severely mentally retarded children was investigated. An economical unit for illumination of stimuli was designed for purposes of the present investigation and for possible use in nonspeech communication training of mentally retarded children. In Experiment 1, the illumination of black stimuli on white backgrounds failed to facilitate discrimination learning. In Experiment 2, however, illumination of white stimuli on black backgrounds facilitated discrimination learning. The findings in the second experiment support the use of changes in illumination as an attention-influencing feature of nonspeech communication keyboards for retarded children.

Attention↗
PubMed1981

Quality of learning of severely retarded adolescents.

A modified discrimination-reversal task identical to that used by Rumbaugh (1971) was employed to assess the quality of learning of severely retarded adolescents. Subjects initially were trained to criterion on a series of multi-dimensional object-discrimination problems (A+B-). Subsequent to one reversal trial on each problem (A-B+), one of three postreversal conditions was introduced: (a) a standard discrimination-reversal condition (A-B+), (b) a condition that substituted a novel stimulus for A (B+C-), or (c) a condition that replaced B with a novel stimulus (A-C+). Subjects' performance on the modified discrimination-reversal task was the same level for all three conditions. In comparison to earlier findings with nonhuman primates, results were interpreted as indicative of mediational learning processes.

Adolescent↗
PubMed1980

Reference: the linguistic essential.

Three chimpanzees learned to label three edibles as "foods" and three inedibles as "tools". Two chimpanzees could then similarly categorize numerous objects during blind trial 1 tests when shown only objects' names. The language-like skills of the chimpanzee who failed (Lana) illustrates that apes can use symbols in ways that emulate human usage without comprehending their representational function.

Animal Communication↗