College-student subjects engaged in judgments of numerosity received stimulus arrays on a computer screen that varied in their number level (low, medium, and high), the speed with which the array developed (slow, medium, or fast), and the density of the items in the array (low or high density). The subjects overestimated number when the array was small (75-125 items) but significantly underestimated number when it was at a medium (150-250) or high level (550-650). Density of array items was a significant variable, since subjects showed more underestimation under the high-density condition. Additionally, there was a speed x density interaction. The results are discussed with respect to which class of variable, sensory or cognitive, most influences perceived numerosity. Although they deal with the animal literature, Davis and Perusse (1988), in their excellent review, distinguish among a number of approaches to the measurement of numerical competence. One of the approaches, estimation, is different from subititing because the subject is re

College students actively felt complex objects for 3 sec, and, after delay intervals of 5, 15, 30, or 45 sec, they received either the same object or a different object for comparison. In a signal detection framework, it was observed that d' scores were significantly higher for the 5-and 15sec intervals than for the 30-and 45-sec intervals. Although a clearly negatively accelerated function was not obtained, this is one of the rare instances in which any decay function has been observed for haptic memory. Although it seems counterintuitive that the entire short-term-memory decay function occupies the narrow band extending from 15 to 30 sec, it is clear from previous studies that short-term haptic memory is unique. Results were discussed in terms of findings in both active-and passive-touch experiments.Invited speakers will include Graham Hitch, Asher Koriat, Michael Pressley, and Wolfgang Schneider. The workshop program will include oral presentations, guest speakers, and poster presentations.The registration fee is 80,000 Italian Liras for participants and 40,000 Italian Liras for students. Payment of the fee should be addressed to PSY.CO 41554/0 Cassa di Risparmio di Trieste, Sede Centrale, Via Cassa di Risparmio 10, 34100 Trieste.

This experiment investigated the effect of interstimulus interval within the range of 0 to 600 msec, in sensory preconditioning. The basic design was: 10 preconditioning trials to light and tone; GSR conditioning to light with shock UCS for 10 trials; 4 tests to tone. 4 groups of 20 Ss were used in different tone-light interstimulus intervals during preconditioning. The interval differences were 0, 100, 400, and 600 msec., tone preceding light. The groups differed significantly in response strength during the tests to the tone, with order of response magnitude from lowest to highest being 600, 0, 100, and 400; an order similar to that found in interstimulus interval curves in ordinary conditioning and in elements of a compound CS.

No abstract

Albino rats were raised from birth in an environment of music in an attempt to assess the effects of early exposure to specific musical forms on subsequent preference behavior. Ss were housed in groups in sound chambers. One group was exposed to selections of the music of Mozart for 12 hr. a day for 52 days; a second group to the music of Schoenberg. In the test situation when the Ss were given an opportunity to select Mozart or Schoenberg music, the Mozart Ss displayed a significant preference for Mozart music. No preference was found among the Schoenberg Ss or among the control Ss raised in a similar environment devoid of music. These results show that early exposure may influence later choice behavior and perhaps point to some attachment process analogous to imprinting. However, questions arise as to why only the Mozart Ss "imprinted." A poss.ible explanation for this is offered.