A two interval forced choice constant stimuli method was used to determine: (i) the point of subjective equality (PSE); and (ii) the just-noticeable-difference (JND) in contrast for two luminance gratings, one held in short-term visual memory. Psychometric functions for delayed contrast discrimination were determined as a function of spatial frequency from 1 to 8 c/deg, reference contrast from 5 to 60% and inter-stimulus interval from 1 to 10 sec. The PSE for remembered contrast was invariant with spatial frequency and inter-stimulus interval for the three reference contrast levels tested. The JND contrast plotted against spatial frequency followed a U-shaped function with lowest thresholds at around 4 c/deg. The threshold function translates parallel to the sensitivity axis with an increase in either the reference contrast or the inter-stimulus interval. However, the bandpass shape of the threshold function is invariant with both reference contrast and inter-stimulus interval. At 1, 3 and 10 sec inter-stimulus intervals, contrast JNDs increase with reference contrast according to a power law with an average exponent of 0.70. Contrast JNDs also increase as a power function of the inter-stimulus interval with an average exponent of 0.38 for the three reference contrasts tested.

Subjective wellbeing (SWB) has been widely accepted as one of the most important elements of successful ageing. The present study explores the impact of two well-established correlates of SWB: physical activity and personality. Physical activity and each of the Big Five personality traits are consistent predictors of SWB, but there has been little research on whether certain personality traits enhance or hinder the psychological benefits of physical activity in older adults. This study examines the interactions of leisure-time physical activity and personality traits on SWB, and whether such interactions vary between older adults in Hong Kong (HK) and older adults in the United Kingdom (UK). Altogether, 349 participants (178 HK, 171 UK; 157 males, 192 female) aged 50 years or above (mean age = 61.84 ± 8.46 years old) completed an online assessment of: (1) leisure-time physical activity (Godin–Shephard Leisure-Time Physical Activity Questionnaire); (2) personality traits (Big Five Inventory); and (3) SWB (Satisfaction with Life Scale, Positive and Negative Affect Schedule). Results showed that agreeableness, conscientiousness, extraversion, neuroticism, openness to experience, and physical activity were all significantly related to SWB in the expected direction. The relationship between physical activity and SWB was moderated by extraversion and by openness to experience: higher levels of these two traits significantly enhanced the relationship. None of the interactions varied between the HK and UK samples. The expected negative relationship between neuroticism and SWB, however, was significantly stronger in the UK sample than in the HK sample. The findings of the present study indicate that personality needs to be considered when promoting and providing physical activity for older adults, although more research is needed to further explore how this can work effectively.

Stereo thresholds for 84% correct detection of sinusoidal disparity corrugations depicted by narrow-band-filtered random dot stereograms were determined for surfaces as a function of (i) luminance center spatial frequency and (ii) disparity modulation frequency. In addition, supra-threshold depth matching functions for two amplitudes of peak-to-trough depth were determined using similar stimuli. Disparity thresholds followed a U-shaped function when plotted against luminance centre spatial frequency from 1 to 8 c/deg. The threshold functions for the three highest corrugation frequencies (ranging from 0.25 to 1 c/deg) formed a single family with a similar bandpass shape and a peak sensitivity at ca 4 c/deg. At the lowest frequency of depth modulation (0.125 c/deg) the shape of the luminance spatial frequency threshold function showed a reduced sensitivity to depth modulations when portrayed by patterns with high luminance centre frequencies (8 c/deg). The similarity of the threshold functions reveals luminance and corrugation frequency to be largely independent dimensions. The finding that the functions are not identical provides some evidence to support a weak luminance spatial frequency selectivity in stereoscopic channels tuned to corrugation frequency.

We compared performance of Japanese and British observers in deciphering images depicting Japanese interpersonal relationships. 201 Japanese and 215 British subjects were assessed by means of a test consisting of 31 photograph problems accompanied by two or three alternative solutions one of which was correct. Japanese subjects outperformed British subjects on the test overall (z = 3.981, p < 0.001). A two-factor ANOVA (culture x gender) was performed for each of the problems. A cultural effect was found in 17 problems. Surprisingly, British subjects outperformed Japanese subjects in 7 of these problems. There was a gender effect in 4 problems and a culture x gender interaction in 6 problems. The results indicate that cultural experience facilitates nonverbal appraisal of interpersonal relationships, but it may sometimes cause specific errors. Differences in the perceptual cues used suggest that British subjects had difficulty reading Japanese facial expressions.

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