Biomedical subjects

D L Oden

Publications and source records attributed to D L Oden.

4 recordsLinked to original sources

PubMed1997

Language-naive chimpanzees (Pan troglodytes) judge relations between relations in a conceptual matching-to-sample task.

Three chimpanzees with a history of conditional and numeric token training spontaneously matched relations between relations under conditions of nondifferential reinforcement. Heretofore, this conceptual ability was demonstrated only in language-trained chimpanzees. The performance levels of the language-naive animals in this study, however, were equivalent to those of a 4th animal--Sarah--whose history included language training and analogical problem solving. There was no evidence that associative factors mediated successful performance in any of the animals. Prior claims of a profound disparity between language-trained and language-naive chimpanzees apparently can be attributed to prior experience with arbitrary tokens consistently associated with abstract relations and not language per se.

Animals↗

PubMed1990

Infant chimpanzees spontaneously perceive both concrete and abstract same/different relations.

We used a familiarization-novelty procedure to determine whether 4 infant chimpanzees spontaneously perceive the sameness of and the difference between both concrete objects and relations between objects. In Experiment 1, a single object was presented on the Familiarization Trial 1 and the animal's looking time recorded. On the Test Trial 2, an object was presented that was either identical to or different from that shown on Trial 1. Looking times on Test Trial 2 were less when the same item had been presented on the preceding familiarization trial. Novel items on Trial 2 were attended to longer, indicating that the infant chimpanzees perceived concrete objects were either the same or different. In Experiment 2, a single pair of objects was presented on the Familiarization Trial 1, and handling time was measured. The objects in a pair were either the same or different (e.g., AA vs. CD). On the Test Trial 2, a new object pair (e.g., BB vs. EF) was presented that instantiated either the relation shown on Trial 1 or the alternative relation. Handling time on Trial 2 was influenced by the relation instantiated on Trial 1. Handling times on Test Trial 2 were less when the identical relation had been presented on the preceding familiarization trial. Novel relations on Trial 2 were attended to relatively longer. This result indicates that infant chimpanzees perceive similarities and differences between abstract relations as well as between concrete objects. That is to say, they perceived relations between relations in Experiment 2. Despite this ability to perceive both concrete and abstract "same/different" relations, the same chimpanzees subsequently failed to use the latter knowledge in a matching-to-sample task in Experiment 3. Although they successfully matched single objects, they were unable to match object pairs instantiating the same relation (e.g., if AA then match BB; if CD then match EF). These results contradict claims that failure to learn an instrumental discrimination involving abstract relations reflects an inability to detect such relations. In every species there may be a disparity between the ability to perceive spontaneously a property of the world and the ability to use the concept instrumentally.

Aging↗

PubMed1988

Spontaneous transfer of matching by infant chimpanzees (Pan troglodytes).

Four infant chimpanzees learned a matching-to-sample task when only two training stimuli were used. They then spontaneously transferred the matching concept to novel items, including three-dimensional objects and fabric swatches, without any experimenter-provided differential feedback. These results support the view that the matching concept is broadly construed by chimpanzees from the beginning and does not depend upon explicit training.

Animals↗

PubMedDate not supplied

A minimum-stress procedure for repeated measurements of nociceptive threshold and analgesia.

A procedure was developed which allows repeated measurement of threshold responses to a thermal pain stimulus administered to an unrestrained animal. The apparatus consists of a metal plate whose temperature can be rapidly incremented and decremented. The device was tested with rats using two experimental procedures. In a titration procedure, temperature was raised gradually until the subject licked its paws. At this time, the temperature was gradually decreased, with the amount of decrement determined by the duration of the paw licking. In a discrete trials procedure, temperature was increased rapidly until paw licking occurred, and then returned rapidly to room temperature. Morphine reliably reduced the responses to heat. The effect was dose-dependent and diminished with repeated doses.

Analgesia↗