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841.
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Men in mixed-gender psychotherapy groups form male subgroups that serve the cause of gender identity development. The resulting enhancement of masculine identifications allows men to more fully participate in the interactional work of the whole group. The author details four stages in the evolution of the male subgroup, and compares these stages to the structure and function of initiation ceremonies in traditional societies.  相似文献   
844.
The perceived spatial frequency of a visual pattern can increase when a pattern drifts or is presented at a peripheral visual field location, as compared with a foveally viewed, stationary pattern. We confirmed previously reported effects of motion on foveally viewed patterns and of location on stationary patterns and extended this analysis to the effect of motion on peripherally viewed patterns and the effect of location on drifting patterns. Most central to our investigation was the combined effect of temporal modulation and spatial location on perceived spatial frequency. The group data, as well as the individual sets of data for most observers, are consistent with the mathematical concept of separability for the effects of temporal modulation and spatial location on perceived spatial frequency. Two qualitative psychophysical models suggest explanations for the effects. Both models assume that the receptive-field sizes of a set of underlying psychophysical mechanisms monotonically change as a function of temporal modulation or visual field location, whereas the perceptual labels attached to a set of channels remain invariant. These models predict that drifting or peripheral viewing of a pattern will cause a shift in the perceived spatial frequency of the pattern to a higher apparent spatial frequency.  相似文献   
845.
In four studies, 3-, 6-, and 9-month-old human infants were tested in a discrimination learning task in which visual fixation to a particular stimulus or lateral position was reinforced with an auditory stimulus. In Experiment 1, all age groups exhibited acquisition, extinction, and reinstatement of fixation to the reinforced target or position. Experiment 2 revealed that 3-month-olds retained the positional discrimination but not the stimulus discrimination after a 5-min delay between acquisition and extinction; older infants retained both types of discriminations. In Experiments 3 and 4 we investigated a possible developmental shift in the dominance of positional versus stimulus cues by training infants on displays in which stimulus and position were confounded and then by dissociating the cues on test trials. Results from both experiments indicated positional cue dominance for young infants and stimulus cue dominance for older infants. The findings are discussed in terms of differences in the attentional demands elicited by proprioceptive versus exteroceptive cues.  相似文献   
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In this paper, we describe software that turns a Macintosh computer into an off-the-shelf tool for experiments on visual search. Our design goals included portability (between members of the Macintosh computer family and between various research settings), user-friendliness (equivalent to Macintosh programming standards), flexibility (to allow replication and extension of important experiments on visual search), and adaptability (very short design-to-data and data-to-analysis turnaround times). We describe how the software meets these goals in three major phases of an experiment: stimulus construction, experimental control, and statistical analysis. We then list several landmark studies of visual search that can be easily designed and extended with the software. Finally, we outline plans for expanding the experimental variations that will be supported in future versions of the software.  相似文献   
848.
Phonetic segments are coarticulated in speech. Accordingly, the articulatory and acoustic properties of the speech signal during the time frame traditionally identified with a given phoneme are highly context-sensitive. For example, due to carryover coarticulation, the front tongue-tip position for HI results in more fronted tongue-body contact for a /g/ preceded by /l/ than for a /g/ preceded by /r/. Perception by mature listeners shows a complementary sensitivity—when a synthetic /da/-/ga/ continuum is preceded by either /al/ or /ar/, adults hear more /g/s following HI rather than Irl. That is, some of the fronting information in the temporal domain of the stop is perceptually attributed to /l/ (Mann, 1980). We replicated this finding and extended it to a signaldetection test of discrimination with adults, using triads of disyllables. Three equidistant items from a /da/-/ga/ continuum were used preceded by /al/ and /ar/. In the identification test, adults had identified item ga5 as “ga”, and dal as “da”, following both /al/ and /ar/, whereas they identified the crucial item d/ga3 predominantly as “ga” after /al/ but as “da” after /ar/. In the discrimination test, they discriminated d/ga3 from dal preceded by /al/ but not /ar/; compatibly, they discriminated d/ga3 readily from ga5 preceded by /ar/ but poorly preceded by /al/. We obtained similar results with 4-month-old infants. Following habituation to either ald/ga3 or ard/ga3, infants heard either the corresponding ga5 or dal disyllable. As predicted, the infants discrimi-nated d/ga3 from dal following /al/ but not /ar/; conversely, they discriminated d/ga3 from ga5 following /ar/ but not /al/. The results suggest that prelinguistic infants disentangle consonant-consonant coarticulatory influences in speech in an adult-like fashion.  相似文献   
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