How contrast affects stereoacuity

Stereoacuity and its dependence on contrast were measured at four spatial frequencies separated by 1 octave steps. Using a method of adjustment, observers adjusted the retinal disparity of an aperiodic narrow-band stimulus until it appeared in the depth plane defined by two flanking reference lines. Variations in contrast affected stereoacuity (the standard deviation of ten depth settings), with better performance observed at higher contrasts. Data were fit with straight lines (on a log-log plot), indicating a power-law dependence on contrast; the slope was steeper at lower spatial frequencies. These findings are consistent with the idea that disparity is computed from the responses of size-tuned mechanisms characterized by nonlinear contrast transfer functions. In a second experiment, the effects of interocular differences in contrast on stereoacuity were studied for two conditions. In the first condition, one eye always viewed a high-contrast target while the other eye viewed targets of successively lower contrast; in the second condition, one eye always saw a target of near-threshold contrast while the other eye saw targets of successively higher contrast. When the fixed contrast was high, stereoacuity deteriorated steadily as the interocular difference in contrast increased; the loss of stereoacuity was greatest at the lowest spatial frequency. When the fixed contrast was low, however, small increases in the contrast to one eye had no deleterious effect on stereoacuity. Once interocular contrast settings exceeded a certain difference, stereoscopic acuity began to deteriorate at lower spatial frequencies. These results address the issue of the stage of visual processing at which contrast exerts its influence on stereopsis.     

I'm OK if you're OK: On the notion of trusting communication

We consider the issue of what an agent or a processor needs to know in order to know that its messages are true. This may be viewed as a first step to a general theory of cooperative communication in distributed systems. An honest message is one that is known to be true when it is sent (or said). If every message that is sent is honest, then of course every message that is sent is true. Various weaker considerations than honesty are investigated with the property that provided every message sent satisfies the condition, then every message sent is true.This is an expanded version of a paper that appears in the Proceedings of the Second IEEE Symposium on Logic in Computer Science, 1987.     

The disappearance of real and subjective contours

The disappearance characteristics of luminous designs were studied in three experiments. The stimuli were geometric forms set off by either real or subjective contours. Subjective-contour forms fragmented more often and in a manner qualitatively different from that of forms created with real contours. Previewing a real-contour form increased the subsequent fragmentation of that form, but no adaptation effects were noted among forms created with subjective contours, and there was no cross-contour adaptation. These results are interpreted as inconsistent with the position that subjective contours result from the partial activation of feature-analyzer mechanisms in the visual system.     

Learning to utilize information presented over two sensory channels

In three separate experiments, Ss were provided with auditory, visual, or simultaneous auditory and visual information in a classification task. Difficulty of classification was manipulated by varying the stimulus exposure duration. Consistent bisensory facilitation effects were noted for later trials, with interference evident on earlier trials. Exposure duration influenced rate and not amount of learning, with bisensory performance being most affected by duration. A transfer paradigm was used in Experiment III, and little if any transfer was noted between unisensory and bisensory stimulus conditions. It was concluded that Ss were extracting the most salient bisensory stimulus components from the auditory and visual modes of information into a unidimensional information configuration.     

The impact of television,print, and audio on children's recall of the news.

Recent research has shown that children remember more from television news than from print news, a finding that has been explained by the extra mnemonic support offered by redundant television pictures (the dual‐coding hypothesis). The present study was designed to examine three alternative explanations, which attribute children's superior recall of television news to (a) underutilization of the print medium, (b) a recall advantage of listening compared with reading, and imperfect reading ability. A sample of 192 fourth and sixth graders was presented with children's news stories, either in (a) their original television form, (b) a bare print version, a print version supplemented with photo material or in (d) an audio version. Results indicated that the television presentation was remembered better than any of the other three versions. The results of the study were consistent with the dual‐coding hypothesis, whereas no support was found for the alternative explanations tested in the study.     

Musical stem completion: humming that note

This study looked at how people store and retrieve tonal music explicitly and implicitly using a production task. Participants completed an implicit task (tune stem completion) followed by an explicit task (cued recall). The tasks were identical except for the instructions at test time. They listened to tunes and were then presented with tune stems from previously heard tunes and novel tunes. For the implicit task, they were asked to sing a note they thought would come next musically. For the explicit task, they were asked to sing the note they remembered as coming next. Experiment 1 found that people correctly completed significantly more old stems than new stems. Experiment 2 investigated the characteristics of music that fuel retrieval by varying a surface feature of the tune (same timbre or different timbre) from study to test and the encoding task (semantic or nonsemantic). Although we did not find that implicit and explicit memory for music were significantly dissociated for levels of processing, we did find that surface features of music affect semanticjudgments and subsequent explicit retrieval.     

Psychology at the intersection of work and family: recommendations for employers, working families, and policymakers

Demographic data show that major changes have been occurring in the everyday lives of families over the last generation, with the majority of mothers of young children in the workforce and an increasing number of men and women assuming caregiving responsibilities for older relatives. Thus, the 2 primary identities of most adults, defined by their multiple family and work roles, need to be coordinated in ways that promote positive family outcomes, returns on investments for employers, and societal values. Despite changes in the workforce, the world of work is still largely organized for a family model that is increasingly rare--one with a stay-at-home caregiver. Recommendations based on psychological and other social science research are offered to align the needs of working families and employers.