Visual cliff

Abstract: Facial expressions of emotion are not merely responses indicative of internal states, they are also stimulus patterns that regulate the behavior of others. A series of four studies indicate that, by 12 months of age, human infants seek out and use such facial expressions to disambiguate situations. The deep side of a visual cliff was adjusted to a height that produced no clear avoidance and much referencing of the mother. If a mother posed joy or interest while her infant referenced, most infants crossed the deep side. If a mother posed fear or anger, very few infants crossed. If a mother posed sadness, an intermediate number crossed. These findings are not interpretable as a discrepancy reaction to an odd pose: in the absence of any depth whatsoever, few infants referenced the mother and those who did while the mother was posing fear hesitated but crossed nonetheless. The latter finding suggests that facial expressions regulate behavior most clearly in contexts of uncertainty.

Abstract: Cognitive decline is apparent in the early stages of Huntington's disease and progressively worsens throughout the course of the disease. Expression of the human Huntington's disease mutation in mice (R6/2 line) causes a progressive neurological phenotype with motor symptoms resembling those seen in Huntington's disease. Here we describe the cognitive performance of R6/2 mice using four different tests (Morris water maze, visual cliff avoidance, two-choice swim tank, and T-maze). Behavioral testing was performed on R6/2 transgenic mice and their wild-type littermates between 3 and 14.5 weeks of age, using separate groups of mice for each test. R6/2 mice did not show an overt motor phenotype until approximately 8 weeks of age. However, between 3.5 and 8 weeks of age, R6/2 mice displayed progressive deterioration in specific aspects of learning in the Morris water maze, visual cliff, two-choice swim tank, and T-maze tasks. The age of onset and progression of the deficits in the individual tasks differed depending on the particular task demands. Thus, as seen in humans with Huntington's disease, R6/2 mice develop progressive learning impairments on cognitive tasks sensitive to frontostriatal and hippocampal function. We suggest that R6/2 mice provide not only a model for studying cognitive and motor changes in trinucleotide repeat disorders, but also a framework within which the functional efficacy of therapeutic strategies aimed at treating such diseases can be tested.

Abstract: Part 1 Experimental psychology in the 30s (1932-1942): bilateral transfer of the conditioned response in the human subject, J.J. Gibson and G. Raffel retention and the interpolated task, with james J. Gibson sensory generalization with voluntary reactions a systematic application of the concepts of generalizaton and differentiation to verbal learning retroactive inhibition as a function of degree of generalization between tasks retrospect and prospect - are theories recycles?. Part 2 Comparative research on learning and development (1952-1970): the role of shock in reinforcement the effect of prolonged exposure to visually presented patterns on learning to discriminate them, with R.D. Walk the effectiveness of prolonged exposure to cutouts vs. painted patterns for facilitation of discrimination behaviour of light and dark reared rats on a visual cliff, with R.D. Walk and T.J. Tighe development of perception - discrimination of depth compared with discrimination of graphic symbols, reprinted from J.C. Wright and J. Kagan (eds.) the development of perception as an adaptive process, Eleanor J. Gibson retrospect and prosepct - comparative psycholoogy and animal cognition. Part 3 Perception - psychophysics to transormations (1954-1959): the effect of training on absolute estimation of distance over the ground, with R. Bergman the effect of prior training with a scale of distance on absolute and relative judgments of distance over ground, with R. Bergman and J. Purdy distance judgment by the method of fractionation, with J. Purdy continuous perspective transformations and the perception of ridig motion with J.J. Gibson motion parallax as a determinant of perceived depth with J.J. Gibson, O.W. Smith and H. flock retrospect and prospect - psychophysics to computation. Part 4 Perceptual learning (1955-1969): perceptual learning - differentiation of enrichment? with J.J. Gibson reply by L. Postman - association theory and perceptual learning what is learned in perceptual learning? a reply to professor postman perceptual learning perceptual development and the reduction of uncertainty trends in perceptual development retrospect and prospect - the coming of age of perceptual development. Part 5 Years of significance - research on reading (1965-1977): learning to read confusion matrices for graphic patterns obtained with a latency measure with F. Schapiro and A. Yonas the ontogeny of reading perceptual learning and the theory of word perception how perception really develops: a veiw from outside the network in D. Laberge and S.J. Samuels (eds.) reading in retrospect - perception, cognition or both?. Part contents.

Abstract: To examine the influences of facial versus vocal cues on infants’ behavior in a potentially threatening situation, 12-month-olds on a visual cliff received positive facial-only, vocal-only, or both facial and vocal cues from mothers. Infants’ crossing times and looks to mother were assessed. Infants crossed the cliff faster with multimodal and vocal than with facial cues, and looked more to mother in the Face Plus Voice compared to the Voice Only condition. The findings suggest that vocal cues, even without a visual reference, are more potent than facial cues in guiding infants’ behavior. The discussion focuses on the meaning of infants’ looks and the role of voice in development of social cognition.