Capturing lightness between contours

Homogeneously coloured bars may exhibit lightness differences at the intersections. A well-known example is the Hermann grid illusion, where crossing white bars on a black background show dark patches at the crossings. Jung (1973, Handbook of Sensory Physiology volume VII/3, pp 1-152) found that the dark patches persist when thin outlines are drawn at the intersections, and are even visible in foveal vision. Recently, it has been shown that making distortions to the contours of a Hermann grid-like configuration results in the disappearance of the illusory dark spots (Geier et al, 2008 Perception 37 651 665). We show that thin outlines at the crossings of the distorted Hermann grid induce lightness differences in the same direction as in the original Hermann grid illusion, even in foveal vision and in displays consisting of two crossing bars. Our experiments reveal that the induced lightness differences are independent of the luminance polarity and shape of the contours at the intersection. We suggest that the effect results from lateral inhibition and an additional spreading and capturing of these differences between luminance contours. A similar capturing between collinear contours may play a role in peripheral vision in the original Hermann grid.     

Vestibular stimulation affects optic-flow sensitivity

Typically, multiple cues can be used to generate a particular percept. Our area of interest is the extent to which humans are able to synergistically combine cues that are generated when moving through an environment. For example, movement through the environment leads to both visual (optic-flow) and vestibular stimulation, and studies have shown that non-human primates are able to combine these cues to generate a more accurate perception of heading than can be obtained with either cue in isolation. Here we investigate whether humans show a similar ability to synergistically combine optic-flow and vestibular cues. This was achieved by determining the sensitivity to optic-flow stimuli while physically moving the observer, and hence producing a vestibular signal, that was either consistent with the optic-flow signal, eg a radially expanding pattern coupled with forward motion, or inconsistent with it, eg a radially expanding pattern with backward motion. Results indicate that humans are more sensitive to motion-in-depth optic-flow stimuli when they are combined with complementary vestibular signals than when they are combined with conflicting vestibular signals. These results indicate that in humans, like in nonhuman primates, there is perceptual integration of visual and vestibular signals.     

Gender Differences in Responding to Conflict in the Workplace: Evidence from a Large Sample of Working Adults

This investigation tested for gender effects in conflict behaviors by examining the ratings made by the bosses, peers, and subordinates of over 2,000 working adults participating in leadership development programs conducted in the U.S.; the effects of two confounding factors—age and organizational status—were controlled in all analyses. Consistent with predictions derived from a gender role analysis, women were rated as significantly more likely to engage in almost every constructive behavior. Also as predicted, men were rated as more likely to engage in active destructive behaviors. Rater gender had no effect for peers and subordinates, but female bosses made more positive ratings of targets than male bosses. In general, bosses rated targets somewhat higher on passive responses.     

Hand dominance influences the processing of observed bodies

In motor tasks, subgroups of lefthanders have been shown to differ in the distribution of attention about their own bodies. The present experiment examined whether similar attentional biases also apply when processing observed bodies. Sixteen right handers (RHs), 22 consistent left handers (CLHs) and 11 relatively ambidextrous inconsistent left handers (ILHs) performed an own body transformation task in which they were instructed to make speeded left–right judgements about a schematic human figure. Attentional biases associated with handedness were found to extend to observed bodies: CLHs’ judgements were faster to the figure’s left side, while ILHs, like RHs, showed facilitated performance to the figure’s right side. These results demonstrate a novel embodiment effect whereby the processing of a static schematic human figure is modulated by an individual’s personal motor capabilities. This finding suggests that motor simulation may contribute to whole body perception in the absence of actual or implied actions.     

Functional characterisation of the extrastriate body area based on the N1 ERP component

Electrophysiological and functional neuroimaging evidence points to the existence of neural populations that respond strongly and selectively to the appearance of the human body and its parts. However, the relationship between ERP and fMRI markers of these populations remains unclear. Here we used a previously identified functional dissociation between two body-selective regions identified with fMRI (extrastriate body area or EBA; fusiform body area or FBA) in order to better understand the source of a body-selective N1 ERP component. Specifically, we compared the magnitude of the N1 elicited by images of fingers, hands, arms and bodies to that obtained for hierarchically-matched control stimuli. We found close agreement between the pattern of body-part selectivity exhibited by N1, and the pattern of BOLD selectivity elicited in a previous study by the same type of stimuli in EBA (in contrast to FBA). We interpret these findings as evidence for EBA as the primary generator of the body-selective N1 component. Our results are an example of the use of functional criteria to distinguish among the possible neural sources of ERP markers.     

Relationship of Ethnic Identity,Acculturation, and Psychological Well‐Being Among Chinese,Japanese, and Korean Americans

The current investigation examined the relationship of ethnic identity, acculturation, and psychological functioning among 334 Chinese, Japanese, and Korean American participants. Multiple regression analyses revealed that ethnic identity and acculturation differentially predicted well‐being on the basis of ethnic group membership. Results also indicated that a bicultural worldview was positively associated with psychological well‐being. Implications for counseling and recommendations for future research are discussed.     

Measuring “intuition” in the SRT generation task

We address some concerns related to the use of post-trial attribution judgments, originally developed for artificial grammar learning (AGL), during the version of the serial reaction time (SRT) task used by Fu, Dienes, and Fu (2010). In particular, intuition attributions, which are central to Fu et al.’s arguments, seem problematic: This attribution is likely to be made when stimuli contain several competing sources of information to which subjective feelings could be attributed. The interpretation of intuition attributions in Fu et al.’s SRT generation task is problematic because the procedure involved a 2-element sequence where items varied only in position. In our view, responses categorised as intuitions might have been a variety of guess response where neither judgement knowledge nor structural knowledge were conscious. The results would then be compatible with previous findings showing that people can control the use of unconscious structural knowledge even when judgement knowledge is unconscious.     

The community substance use environment: The development and predictive ability of a multi‐method and multiple‐reporter measure

This study tested the feasibility and utility of developing a multiple‐method and multiple‐reporter measure that describes the community substance use environment. Data on community‐level norms and availability of substances were reported by 5261 students and 181 prevention‐focused community leaders (CL) involved in the 28 promoting school–university–community partnerships to enhance resilience (PROSPER) Project communities between 2002 and 2005. Additionally, locations of alcohol and tobacco outlets were geocoded. Initially, these four subscales were aggregated to measure the community substance use environment. Analyses demonstrated this measure was associated with community rates of adolescent reported cigarette use, but it was not associated with community rates of adolescent reported alcohol use. Further analyses tested the relative strength of the four different subscales in predicting rates of student use. Implications of these results for the field of community‐based prevention are discussed, as well as limitations and future directions. Copyright © 2009 John Wiley & Sons, Ltd.