Binocular cues in the perception of distance of a point source of light

The ability to make egocentric distance estimates of a single point source of light, seen in darkness and without the cues of changing size and luminance, was investigated in sixteen observers. The attenuation required to maintain constant luminance, when the target was viewed from different distances, was shown to follow the inverse square law providing the angle subtended by the light was less than 20 s arc. Distance changes were also simulated by means of a split mirror which produced vergence cues, or by test lenses to provide accommodation cues. Over the range 0.5 to 9.2 m distance estimates were surprisingly accurate, although there was some overestimation of near and underestimation of far distances. Most observers made good judgements when only convergence cues were varied, whereas no observers made consistently good judgements when only accommodation cues were varied. The difficulties are discussed in terms of the accommodation-convergence link. When distance was simulated by changing convergence and accommodation cues, estimates were not as good as when real distance was changed. Since good estimates were made with brief target exposures, these judgements were not based on subsequent convergence or accommodation changes. It is suggested that the metric or reference against which the apparently absolute judgements were made was the efferent demand signal associated with a 'resting' position of convergence in darkness.     

Creative Problem Solving in Small Groups: The Effects of Creativity Training on Idea Generation,Solution Creativity,and Leadership Effectiveness

This investigation evaluated the degree to which creativity training, idea generation instruction, and creative process impacted idea production, creativeness of solutions, and leadership effectiveness. Three sets of hypotheses were tested with a 114 groups of adults. First, groups whose members had some (i.e., one CPS course) or advanced training (i.e., graduate-level study in creativity or creativity professionals) were significantly more effective at idea generation than groups without training. Furthermore, leaders with some and advanced training were perceived to be significantly more effective than those with no creativity training. With respect to creativeness of solutions, the advanced training groups outperformed all others. The second set of hypotheses focused on the effectiveness of idea generation instruction (i.e., instructions without brainstorming, brainstorming, and brainstorming with criticism). Analysis revealed no significant difference for idea generation instruction relative to idea production or creativeness of solutions. The final set of hypotheses examined the use of a simple process structure for groups without prior creativity training (i.e., distinct phases for idea generation and solution development). Analysis revealed that those meetings that followed a simple process structure out performed groups that did not follow a process for both idea generation and creativeness of solutions. Further results are presented and implications discussed.