Risk preferences in young children: early evidence of individual differences in reaction to potential gains and losses

New methods were developed for studying risky decision making in children as young as age five. Each child was given a block of ‘gain’ trials, for example, a choice between a sure gain of one prize and a 50:50 chance of gaining either two prizes or no prize, and a block of ‘loss’ trials, for example, a choice between a sure loss of one prize and a 50:50 chance of losing either two prizes or no prize. We were thus able to compare risky choice for gains and losses at the level of the individual child. In each of two experiments a variety of individual difference variables were measured, including in Experiment 2, the child's parent's scores on the same task. Across experiments, the preponderance of choices was of the risky option. However, most children and adults made more risky choices in the domain of losses than in the domain of gains. Predictors of individual differences in children included shyness, impulsivity, and the risk taking of the child's parent. We suggest that methods are now in place to encourage further studies of decision processes in young children. Copyright © 2003 John Wiley & Sons, Ltd.     

Identification of temporal coherence between auditory and visual channels

Attention, Perception, & Psychophysics - The accuracy of identification of the temporal coherence between auditory and visual channels was examined. Random sequences of sound and light bursts...     

Discriminability in length of lines in the Müller-Lyer figure

Receiver-operating characteristics for the discriminability in the length of the lines of the Müller-Lyer figure were obtained by the rating method of detection theory. Six observers judged the shaft length of the lines of the figure with reference to the same standard line. Maximum-likelihood estimates of the index of (discriminability,d’, were a linear function of the difference in the length of the lines, but the functions did not pass through the origin because of a constant error of judgment. Because discriminability was determined by ROC analysis, the constant error could not be attributed solely to changes in criterion placement; instead, it showed that the Müller-Lyer figure induced a change in the discriminability of the lines.     

Temporal and spatial features in detecting one- and two-dimensional constraints in complementary visual displays

Spatial complements of visual displays of one- and two-dimensional Markov spatial constraints were successively presented for discrimination. Although each complement alone was sufficient for discrimination, spatial complements interfere when presented successively in time. Substantial changes in performance are observed for temporal separations as short as 10 msec and for spatial separations as short as 1 min in visual angle. Complete processing appears to take place in the interval between successive displays: thresholds are constant for a constant sum of display duration plus the interfield interval. Implications of complementary interference for a general theory of visual masking are briefly discussed.     

Patterns of interprofessional conflict resolution on school child study teams

This study proposes to investigate perceived and desired methods of conflict resolution by school psychologists, social workers, and learning disability specialists. Data were based on responses to a questionnaire which requested information on how decisions were reached or should have been reached when their child study teams were required to classify a child and there were conflicting opinions between professional groups. While majority vote and resolution by the psychologist accounted for the methods most often used in actual resolutions, there were great disagreements between professions as to how resolutions should have been made. Analysis indicates that the school psychologists are generally satisfied because they are the single group most often making final decisions, but they are generating feelings of discontent among other the other groups which suggst that team functioning and decision making, especially during voting, may be overly affected by interprofessional rivalry rather than objective data.     

Identifiability of a class of theories with states not directly observed over trials

The problem of identifying probabilities for sequences involving K underlying states is investigated for experiments in which there are K observed states, with the conditional distribution for these states specified for each underlying state. Conditions for finding unique estimates of the underlying probabilities are outlined for situations in which underlying transitions depend upon the last observed state as well as for situations in which no such dependency is assumed. No restrictions upon the nature of underlying transitions are assumed for a large number of trials. Applications to some known experimental situations are suggested.     

Forward, backward and combined masking: Implications for an auditory integration period

Auditory temporal psychometric functions were obtained for forward masking, backward masking, and for combined forward and backward masking for the case of an impulsive signal in white noise. Temporal psychometric functions show a large interaction between forward masking and backward masking when evaluated against an independence model of performance. The results are not consistent with the concept of a sharp rectangular temporal integrating period (“moment”) to account for the interaction.