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Biomedical subjects

S T Boysen

Publications and source records attributed to S T Boysen.

25 records · Page 2Linked to original sources
PubMed1989

Conspecific recognition in the chimpanzee (Pan troglodytes): cardiac responses to significant others.

The ability of a chimpanzee (Pan troglodytes) to recognize photographs of conspecifics was evaluated with heart-rate measures. Heart rate was recorded before, during, and after viewing photographs of an aggressive chimpanzee, a friendly companion animal, and an unfamiliar chimpanzee. The subject displayed a differential pattern of heart-rate response to the stimulus animals, without prior experience with the photographs. Responses to the aggressive animal were acceleratory, which suggests a defensive response. Respiratory sinus arrhythmia suggested that this response was associated with sympathetic activation. In contrast, responses to the familiar animal were minimal, whereas cardiac deceleration was observed in response to the strange chimp, which likely reflects an orienting response. Results suggest the chimpanzee is able to recognize photographs of individual conspecifics and that heart-rate change can reflect the nature of established social relationships between chimpanzees.

Animals↗
PubMed1987

Simian scribbles: a reappraisal of drawing in the chimpanzee (Pan troglodytes).

Three chimpanzees (Pan troglodytes) were provided with 18 different stimulus pages for drawing. The resulting 618 drawings were coded for drawn marks, and results were compared with early reports on ape drawing (Morris, 1962; Schiller, 1951) and with more recent systematic studies (Smith, 1973). The findings of the present study confirm Smith's observations of a tendency for the animals to draw closer to the center and toward the bottom of the page. No evidence for perceptual balancing was observed in drawings produced on pages with lateral figures, nor was any evidence for closure apparent with complex figures. The present results agree with earlier findings that chimpanzees will engage in drawing activities without training or reinforcement, and this behavior may reflect their intrinsic interest in exploratory and manipulative play.

Animals↗
PubMed1986

Cardiac correlates of individual recognition in the chimpanzee (Pan troglodytes).

The ability of a chimpanzee to recognize individuals depicted in photographs was evaluated through the use of heart rate measures. Heart rate was recorded before and during photographic projections of human caregivers, familiar individuals, strangers, and blank control slides. In the absence of explicit training or reinforcement, the chimpanzee displayed a differential pattern of heart rate response to the stimulus categories. Although heart rate responses to all stimuli were predominantly deceleratory, the photographs of caregivers yielded consistently larger responses than other stimuli. Results indicate that the chimpanzee is able to recognize individual humans from novel photographic representations and that heart rate can provide an objective measure of such recognition.

Animals↗
PubMed1985

Visual evoked potentials in the great apes.

Visual evoked potentials (VEPs) in response to flash stimuli were recorded from occipital and central-scalp electrodes in the chimpanzee and gorilla. The most notable occipital component of the VEP was a surface-positive wave (P90), the latency of which decreased with development. Central scalp responses, apparent only in older animals, included a characteristic long-latency 'vertex wave' (N125-P225). Observed responses are similar to those reported for humans and monkeys, but appear to share more specific features of human VEPs.

Animals↗
PubMed1985

Cardiac reactivity and adaptive behavior.

The relationship between adaptive behavioral function and cardiac reactivity to auditory, somatosensory, and visual stimuli was evaluated using a heterogeneous population of developmentally disabled infants and young children. Stimuli of all sensory modalities resulted predominantly in a cardiac deceleration, and the magnitude of these responses varied systematically between subjects. A multiple regression analysis revealed that 60% of the variance in adaptive behavior, as measured by the Adaptive Behavior Scale for Infants and Early Childhood, could be accounted for by age and the cardiac responses. The factor with the greatest predictive weighting was cardiac reactivity to a vibrotactile stimulus, which showed a correlation of .65 with adaptive behavior scores.

Acoustic Stimulation↗
PubMed1984

Cardiac startle and orienting responses in the great apes.

Cardiac patterns of startle and orienting in response to auditory and vibrotactile stimuli were investigated in the infant chimpanzee and gorilla. Results revealed a notable cardiac acceleration in response to the initial presentations of stimuli of either modality. This acceleratory response appeared to reflect the cardiac correlate of startle and was closely associated with the elicitation of somatic startle responses. This initial cardiac acceleration was subject to rapid habituation and was replaced on subsequent trials by cardiac deceleration, which appeared to reflect the orienting response. Results from the chimpanzees and the gorilla were similar, although a slower rate of habituation was apparent in the gorilla. Taken together, these results are highly consistent with those obtained from humans and monkeys, and they provide the first characterization of cardiac patterns associated with startle and orienting responses in the great apes.

Animals↗