Temporal characteristics of a comparator in adaptation to optical tilt

Two groups of eight Ss each and one group of seven Ss were exposed to optical tilts (T) of 50, 40, 30, 20, and 10 deg in succession. Exposure time at each tilt was 3, 15, and 27 min in Groups 1, 2, and 3, respectively. Trend analyses of the functions relating level of adaptation to T showed significant quadratic components for Group 1, quadratic and linear components for Group 2, and only linear components for Group 3. These results were consistent with derivations from a memory-comparator model of perceptual adaptation.     

Dimensional salience as a function of educational attainment and method of discrimination training

The effects of three methods of selective-attention training with 4-sided forms on the salience of an invagination physical dimension in discrimination judgments with a stimulus domain of 12-sided forms were examined for 6-year-old Ss of low and high educational attainment. The results demonstrated that training procedures involving perceptual demonstration or manipulation increase the invagination dimension salience in the 12-sided stimulus domain more than a verbal training procedure for low educational attainment Ss. Implications for the psychophysical study of relatedness of stimulus domains are discussed.     

Interaction of fear effects with habit strength

Four groups of rats received 0, 3, 6 or 9 days of overtraining after having reached stable performance on a continuous reinforcement bar pressing schedule. Half the subjects in each group had previously been designated emotionally reactive or non-reactive in terms of defecation rates in an open-field test. Following training, there were four test days in which bar pressing in each group was examined in the presence or absence of white noise. The major findings were that, in both the reactive and non-reactive groups, white noise produced a fear reaction which significantly depressed bar pressing at low levels of habit strength while having an energizing effect at higher levels. The results were interpreted as supporting Bardach's (1960) hypothesis that anxiety introduced early in practice is more disruptive than when introduced late in practice.