Effects of high-pass and low-pass spatial filtering on face identification

If face images are degraded by block averaging, there is a nonlinear decline in recognition accuracy as block size increases, suggesting that identification requires a critical minimum range of object spatial frequencies. The identification of faces was measured with equivalent Fourier low-pass filtering and block averaging preserving the same information and with high-pass transformations. In Experiment 1, accuracy declined and response time increased in a significant nonlinear manner in all cases as the spatial-frequency range was reduced. However, it did so at a faster rate for the quantized and high-passed images. A second experiment controlled for the differences in the contrast of the high-pass faces and found a reduced but significant and nonlinear decline in performance as the spatial-frequency range was reduced. These data suggest that face identification is preferentially supported by a band of spatial frequencies of approximately 8-16 cycles per face; contrast or line-based explanations were found to be inadequate. The data are discussed in terms of current models of face identification.     

Managing Attitudes Toward High Achievers: The Influence 0f Group Discussion

For a variety of cultural, contextual, and interpersonal reasons, individual achievement often meets with potentially demotivating resistance from the group. In groups of between three and seven members, 397 psychology and social work students, in East and Northern Australian cities (Newcastle and Darwin), indicated their attitudes toward high achievers before, during, and after a group consensus task. In each location, and at both individual and group levels of analysis, initially slightly pro-achiever attitudes, following discussion of the issues, became polarized. Such changes, across diverse settings and groups, indicate that group discussion may be a robust tool, both for empowering teams and encouraging support for individual initiative.     

Component problems in dichotic listening

The experiments reported examined monitoring for semantically defined targets whilst concurrently shadowing (Experiment I) or listening silently (Experiment II). The word lists for monitoring were either visual or auditory. Monitoring and shadowing accuracy showed less interference when presentation was bimodal than when it was dichotic. However, monitoring latency and recognition memory for shadowed material did not show this effect. It is argued that these data reveal the existence of a number of different sources of potential difficulty in dichotic listening situations and the nature of these is discussed.     

Spatial organization in the free recall of pictorial stimuli

Thirty-one young adults were presented with a series of visual arrays each containing drawings of objects. Free recall of the objects on each visual array could be organized by the spatial location of the objects or by another type of organization. The other type of organization was different on each array and comprised semantic, shape, colour, size, orientation or phonetic categories. The results showed that free recall could be organized by spatial location or by semantic, shape, colour or size categories. However, only semantic and colour category organization were found to correlate significantly with recall. To account for the correlation results, two distinct general forms of organization are hypothesized.     

Imagery and associative memory in children

Second and sixth graders, ages 7–8 and 11–12, respectively, were presented with lists of pairs of nouns. They were asked to represent each pair in memory as a single interactive image, as two separate images, or by a control procedure. After presentation of the pairs, the children were tested either by cued or noncued recall. The difference between the interaction condition and the other conditions appeared in recall measures which reflect pairwise organization in memory (cued recall, pair recall, conditional recall probabilities, and χ²) to a much greater extent than in measures of individual item recall. The results were interpreted as supporting an imagery-organization hypothesis.     

Central and peripheral vision in early infancy

The size of the effective visual field during the first weeks of life is found to depend on two factors: It increases with age, but it contracts in the face of competition from ongoing activity such as fixation of a central stimulus or non-nutritive sucking.     

The haptic perception of curvature

Ninety-two subjects, schoolchildren and undergraduate and postgraduate students, took part in a series of experiments on the haptic perception of curvature. A graded series of surfaces was produced using piano-convex lenses masked off to produce curved strips that could be explored without using arm movements. Thresholds were measured using the constant method and a staircase procedure. Experiments 1 and 2 yielded data on the absolute and difference thresholds for curvature. Experiment 3 demonstrated that the effective stimulus for curvature is represented by the overall gradient of a curved surface. Using this measure, it was shown that the present absolute thresholds for curvature are lower than those previously reported. In Experiment 4, absolute thresholds were compared using spherical and cylindrical curves: the results showed that, at least with the narrow strips used, the type of curvature does not exert a significant influence on performance. In Experiment 5, the subjective response to curvature was assessed using a rating procedure. Power functions are reported, although the relationship between stimuli and responses had a strong linear component. This suggests that haptically perceived curvature may be a metathetic rather than a prothetic continuum.