Richard K. Thompson

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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(More)
We review the evidence for three important disparities involving the perception and judgment of identity relations by human and nonhuman primates. First, only humans beyond infancy and adult chimpanzees (Pan troglodytes) with a history of language or token training can explicitly judge relations (same or different) between relations (identity and(More)
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(More)
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(More)
A study of 20 manic patients, with patient and matched control comparisons, showed a two fold increase in life events during the 4 month period before admission to hospital. Life events, independent of affective illness and having significant objective negative impact (i.e. traumatic) were significantly more common. These findings are considered in relation(More)
Eighteen depressed chronic schizophrenic out-patients were matched with non-depressed schizophrenic out-patients. The depressed schizophrenics had had significantly more psychiatric admissions, past depression, past treatment for depression, significantly more had attempted suicide, lived alone, had low self-esteem, had early parental loss and had had more(More)
20 full-term and 20 preterm infants and their mothers were videotaped in the Strange Situation, and the security of their attachment relationships was later determined. Each episode was subsequently divided into consecutive 15-sec intervals, during each of which ratings of facial expressions were performed. From these ratings several summary dimensions of(More)
After listening to a list of as many as six discriminably different 2-second sounds, a bottle-nosed dolphin classified a subsequent probe sound as either "old" (from the list) or "new." The probability of recognizing an old probe was close to 1.0 if it matched the most recent sound in the list and decreased sigmoidally for successively earlier list sounds.(More)