Stimulus generalization of behavioral history: Interspecies generality and persistence of generalization gradients

Four pigeons were exposed to a tandem variable-interval (VI) fixed-ratio (FR) schedule in the presence of a 50-pixel (about 15 mm) square or an 80-pixel (about 24 mm) square and to a tandem VI differential-reinforcement-of-low-rate (DRL) schedule when a second 80-pixel or 50-pixel square was present. The values of the VI and FR schedules were adjusted to equate reinforcement rates in the two tandem schedules. Following this, a square-size continuum generalization test was administered under a fixed-interval (FI) schedule or extinction. In the first testing session, response frequency was a graded function of the similarity of the test stimuli to the training stimuli for all pigeons. These systematic generalization gradients persisted longer under the FI schedule than under extinction.     

The role of transparency in perceptual grouping and pattern recognition.

The shortest stimulus exposure time for which transparency can be seen was examined. In the first experiment, overlapping digits were presented for 120 ms and the luminance in the overlapping regions was varied. Subjects reported, in separate blocks of trials, either the apparent transparency of the digits or the identity of the digits. When the luminance was set so that one set of digits appeared to be seen through the other, recognition of the digits was high. When the luminance in the overlapping regions did not produce impressions of transparency, digit recognition was low. In the second experiment, digit identification at several stimulus durations was compared between stimuli that had luminance that was valid for transparency and stimuli that had invalid luminance. Performance was found to be higher in the valid luminance condition than in the invalid condition after as little as 60 ms exposure duration. This result suggests that the impression of transparency requires only relatively short exposure durations.     

Illusory occluding contours and surface formation by depth propagation.

A novel kind of depth-spreading effect which should be distinguished in various aspects from the known interpolation, averaging, or 'filling-in' phenomena is reported. The demonstrations and experiments suggest that depth from an uncrossed disparity can be extrapolated from, not just interpolated between, illusory or real contours to form perceptually a background surface. In addition, the form of the illusory contour itself could be drastically changed in configuration and sharpness, contingently with perceptual background-surface formation. No such effects of surface and contour formation were observed in the crossed disparity case. Because the illusory contours were enhanced and perceived as illusory 'occluding contours', these effects may be closely related to the 'occlusion constraints' in the real world.     

Deliberate Self‐Harm in Adolescents Aged 12–18: A Cross‐Sectional Survey of 18,104 Students

Little is known about accurate prevalence and associated factors of deliberate self‐harm (DSH) among adolescents in Asian countries. In this study, the prevalence and associated factors of DSH among adolescents in Japan were examined. Data were derived from a cross‐sectional survey using an anonymous self‐report questionnaire and enrolling 8,620 adolescents aged 12–15 and 9,484 aged 15–18. DSH in the previous 12 months was reported by 3.3% (95% CI, 2.9–3.7) of junior and 4.3% (3.9%–4.7%) of senior high school respondents. The prevalence was more than four times as high among girls as among boys for both age groups. DSH was further strongly associated with having suicidal thoughts, having depression/anxiety symptoms, and having used recreational drugs. These associated factors were similar for both sexes and for both older and younger teenagers. A substantial minority of adolescents present with DSH, even among those aged 12–15. The prevalence of DSH in Japan was in the lower ranges of those reported for Western countries. The identified associated factors were not dissimilar from those reported in the West.     

An object-based template for rejection effect

ABSTRACT

In the process of searching for targets, our visual system not only prioritizes target-relevant features, but can also suppress nontarget-related features. Although this template for rejection has been well demonstrated, whether the features (i.e. the objects) or locations are suppressed remains unresolved due to the experimental paradigms in previous studies: in particular, object-based templates for rejection were confounded with location-based inhibition in visual search paradigms. The present study examined an object-based template for rejection by introducing search arrays comprised of two overlapping shapes with search items distributed along the shape's contours. To discourage location-based inhibition, the two shapes were spatially intermingled (Experiment 1), rotated (Experiment 2), or jiggled (Experiment 3). Participants identified the colour of a target cross. The pre-cue indicated the shape in which the target would appear (positive cue condition), the shape in which only distractors would appear (negative cue condition), or the shape that was irrelevant to the current search array (neutral cue condition). In all three experiments, the reaction times for the negative cue condition were shorter than those for the neutral cue condition, which is a hallmark of the object-based template for rejection effect, even under conditions in which location-based inhibition was discouraged.     

Are illusory contours a cause or a consequence of apparent differences in brightness and depth in the Kanizsa square?

The causal flows between the processes responsible for illusory contour clarity, brightness, and apparent depth in the Kanizsa square were examined. The sixty-four stimuli used consisted of all possible combinations of eight disk luminances and eight centre-to-centre separations between nearest disks. Ten subjects were instructed to rate the clarity of the illusory contour and the brightness and apparent depth differences between the Kanizsa square and its surround in each stimulus. On the basis of results obtained with the causal inference method, using partial correlations and path analysis, it is suggested that clarity of illusory contour can be influenced directly by disk separation, and that the output from the process responsible for illusory contour clarity has some effect on the processes responsible for the apparent depth and brightness differences.     

Belief in group interdependence: Facilitating evacuee–host interactions after the Fukushima nuclear accident

After the 2011 Fukushima nuclear accident, intercultural friction and aversion arose between evacuees and host community residents in relocation areas. We examined whether a belief in group interdependence—the extent to which an individual believes that group function is realized through interdependence with related other groups—is consistent with positive interactions between evacuees and hosts. A door-to-door survey of 77 evacuees and 75 hosts revealed that residents with an integrated social identity interacted favorably with both ingroup and outgroup members, and that a belief in group interdependence was consistent with the integration of social identity between the evacuee and host communities. Those findings suggest that a belief in group interdependence can reduce intercultural conflict by allowing both immigrants and host residents to acquire an integrated social identity without the dilemma of internalizing different cultures into an individual's mind.