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Biomedical subjects

J B Pittenger

Publications and source records attributed to J B Pittenger.

8 recordsLinked to original sources
PubMed1990

Body proportions as information for age and cuteness: animals in illustrated children's books.

Growth systematically changes the body proportions of both humans and animals so that the ratio of head height to body height decreases with age. Prior studies have demonstrated that body proportions provide effective information for age perception. To test the proposal that illustrators incorporate this information into their drawings, measurements were made of the head and body heights of 100 pairs of animals appearing in children's picture books. In 93 pairs, the animal intended to be perceived as older had a smaller head-to-body ratio than did the younger animal. Ratings collected for 25 of these pairs showed that both perceived age and cuteness are significantly correlated with body proportions. The magnitudes of the correlations were only modest, suggesting that other aspects of the drawings influenced perceived age and cuteness. In addition, observers reported that body proportions are only one of a variety of factors influencing age and cuteness perception. As has been found in other studies, perceived age and cuteness were negatively correlated.

Adult↗
PubMed1988

A mechanism for the direct perception of change: the example of bacterial chemotaxis.

The relationship between the behavior of single-celled organisms and cognition in higher animals is explored. Recent research and theory in bacterial chemotaxis are presented, together with a discussion of the implications of chemotaxis for perceptual theory. A number of parallels between chemotaxis and perception in higher organisms are drawn. It is suggested that Koshland's model of the chemical processes controlling chemotaxis is an example of a mechanism for direct perception of change and can help elucidate Runeson's work on 'smart mechanisms' of perception. It is argued, more generally, that the growing body of knowledge about the perceptual activities of lower organisms should be used to broaden the factual base on which theories of perception are constructed: eg explication of perceptual parallels between humans and lower organisms should help clarify the nature of these phenomena in humans and, perhaps, help in the development of theories of greater generality. Also, the debate between direct and indirect theories of perception may be advanced by analysis of the specific mechanisms used by lower organisms. Contrasts to mediated perception are pointed out and arguments for the relative simplicity and explanatory power of theories of direct perception are provided.

Animals↗
PubMed1985

Estimation of pendulum length from information in motion.

One hundred and five college students made estimates of the lengths of freely swinging pendulums mounted in an apparatus that masked all but the top few inches of the pendulum string. The law of pendulum motion shows that visible aspects of pendulum motion uniquely specify the length of the pendulum. Thus, information is available in the display that does, if observers are able to use it, allow accurate estimation of length. In three studies estimates were found to be linear functions of actual lengths, though with wide differences in slopes among individual observers. These results, together with statements made during post-experimental interviews, are interpreted as showing that observers use a rule to the effect that length is a linear function of 'speed', where speed appears to be a function of both period and angular velocity.

Cognition↗
PubMed1979

Perceptual information for the age level of faces as a higher order invariant of growth.

Previous work supports the hypothesis that cardioidal strain, a nonlinear topological transformation, offers a plausible mathematical model for the perceived global changes in human craniofacial morphology due to growth. Experiment 1 examined the generality of the effect of this growth transformation on relative age judgments by applying it to profiles of a dog, bird, and monkey. Experiment 2 investigated the abstractness of this transformation by looking at its effect on perceived age level of a Volkswagen "Beetle." In both experiments, cardioidal strain resulted in changes in the perceived age of the nonhuman profiles that were similar to those produced on human faces in earlier work. A second transformation, affine shear, failed to produce as significant an effect on perceived age as cardioidal strain when applied to the same structures. Because cardioidal strain produces changes in structures that do not share an isomorphism of rigid (Euclidian) local features or rigid feature configurations, this transformation seems both sufficiently general and abstract to specify what J.J. Gibson has called a "higher-order invariant of perceptual information.

Discrimination Learning↗
PubMed1977

An illusion of auditory saltation similar to the cutaneous "rabbit".

Trains of brief clicks produced successively at 3 points in a horizontal array were not localized accurately. Observers reported clicks occurring in succession across the spaces between sources as well as at the sources themselves. The illusion is functionally related to interstimulus interval, number of clicks per speaker, and regularity of pulsing. It appears similar to Geldard and Sherrick's cutaneous "rabbit" illusion.

Auditory Perception↗
PubMed1975

Aging faces as viscal-elastic events: implications for a theory of nonrigid shape perception.

A theory for the perception of events is proposed using the concepts of transformational and structural invariants. This approach involves the application of a method of spatial coordinate transformation to characterize the remodeling of faces by growth. By construing growing faces to the viscal-elastic events, the perception of the relative age level faces in made amenable to the proposed event perception analysis. Shear and strain transformation are compared as alternative formulations of growth-produced changes in the shape of human profiles. Thes studies indicate that profiles transformed by strain elicit more reliable rank-order age judgments than those transformed by shear, although shear had a small significant effect. It is also shown that subjects are highly sensitive to small changes in strain, and that perceived identity of a shape is preserved under the strain transformation. The explanatory adequacy of the event perception theory of age information is compared to that of more traditional feature analytic theories.

Aging↗