Lightness effects in Delboeuf and Ebbinghaus size-contrast illusions

We examined lightness effects observed in Delboeuf and Ebbinghaus size-contrast illusions. Results of four experiments are reported. Experiment 1 was conducted with Delboeuf-like stimuli and shows that the disk that appears bigger appears either lighter or darker than the disk that appears smaller, depending on the contrast polarity between disks and background. Experiment 2 shows that the direction of these lightness effects is not influenced by the luminance of the size-contrast inducers. Experiment 3 shows that a similar lightness effect is also observed in modified Ebbinghaus size-contrast displays. Experiment 4 tested the presence of the size-contrast illusion in the stimuli used in experiments 2 and 3.     

Reflections on Averintsev’s Method

The author represents Averintsev’s thought as a response to, and commentary on, Russia’s Silver Age, and describes his particular method of seeing and understanding. The article considers his response to the cultural context in which he worked, focusing mainly on Averintsev’s language, style and syntax, and linking it with his ideal of equilibrium. Finally, the article moves on to Averintsev’s criticism of thinking in polarities.     

Inferences about mechanisms that mediate pattern and flicker sensitivity

Attention, Perception, & Psychophysics - Visual sensitivity to a flickering, sinusoidal grating was assessed in multiple sclerosis patients and control observers. It was found that losses in...     

The biological basis of stress management

A rationale is outlined for the inclusion of a biological approach in stress-management programmes. The biology of the stress response is described in sufficient detail to show the layperson what happens in the body when stress is experienced. An explanation of the biological basis of commonly used coping strategies is given.     

When figure-ground segmentation modulates brightness: the case of phantom illumination

In the phantom illumination illusion, luminance ramps ranging from black to white induce a brightness enhancement on an otherwise homogeneous dark background. The strength of the illusion was tested with regard to the extension of the brightness inducing perimeter, surrounding the target area by manipulating the number of inducers (exp. 1) and the size of the inducers (exp. 2). Participants' task was to rate the difference in brightness between the target area and the background. Results show that the illusion occurs only when the target area is not completely segregated from the background by luminance ramps; vice versa, when the target area is delimited by a continuous gradient, it appears darker than the background. These findings suggest a major role of figure-ground organization in the appearance of the illusion. This hypothesis was tested in a rating task experiment with three types of target area shapes circumscribed by four types of edges: luminance contours, illusory contours, no contours, and ambiguous contours. Illusory contours, just as luminance contours, hinder the illusion and produce a darkening of the target area. A control experiment measured the brightness of the previous stimuli without luminance ramps: all configurations resulted in a darkening of the target area. Results from all experiments suggest that figure-ground segmentation plays a major role in the determination of both illumination and lightness in stimuli with luminance gradients.     

The role of values with personal examples in altering the functions of pain: comparison between acceptance-based and cognitive-control-based protocols

The purpose of the present study was twofold. First, to compare the effect of establishing a motivational context of values on pain tolerance, believability, and reported pain, with three experimental conditions: pain acceptance (ACT condition), pain control (CONT condition), or no values (untrained condition). Second, the study aimed to isolate the impact of adding the corresponding coping strategies to both the ACT and the CONT conditions. Thirty adults were randomly assigned to one of the three experimental conditions. The participants went through the pain task in two occasions (Test I and Test II). In Test I, the effects of the ACT-values protocol (which established pain as part of valued action), the CONT-values protocol (which established high pain as opposed to valued action), and the no-values protocol, were compared. In Test II, the effect of adding the corresponding coping strategy to each condition (defusion for ACT vs. suppression for CONT) was examined. Test I showed a clear superiority of the ACT-values protocol in increasing tolerance and lowering pain believability. In Test II, the superiority of the ACT protocol was replicated, while the CONT protocol proved useful to reduce reported pain, in accordance with previous studies.     

The Enhancement of Visuospatial Processing Efficiency Through Buddhist Deity Meditation

ABSTRACT— This study examined the effects of meditation on mental imagery, evaluating Buddhist monks' reports concerning their extraordinary imagery skills. Practitioners of Buddhist meditation were divided into two groups according to their preferred meditation style: Deity Yoga (focused attention on an internal visual image) or Open Presence (evenly distributed attention, not directed to any particular object). Both groups of meditators completed computerized mental-imagery tasks before and after meditation. Their performance was compared with that of control groups, who either rested or performed other visuospatial tasks between testing sessions. The results indicate that all the groups performed at the same baseline level, but after meditation, Deity Yoga practitioners demonstrated a dramatic increase in performance on imagery tasks compared with the other groups. The results suggest that Deity meditation specifically trains one's capacity to access heightened visuospatial processing resources, rather than generally improving visuospatial imagery abilities.     

Ethnic/cultural identity salience,achievement goals and motivational climate in multicultural physical education classes

ObjectivesThis study investigated the association of ethnic/cultural identity salience with achievement goals and motivational climate in multicultural physical education classes.MethodsQuestionnaires assessing ethnic/cultural identity salience, achievement goals and motivational climate were completed by high school students with Greek (n = 927) and non-Greek (n = 366) ethnic origin. The ethnic/cultural identity salience questionnaire comprised four factors suggesting ethnic belonging, assimilation, feelings of being on the fringe of ethnic identity, and lack of desire to interact with members of other ethnic groups.ResultsMultilevel modeling analyses indicated that task orientation and class learning oriented climate were positively linked with ethnic belonging and assimilation from the larger culture. On the other hand, ego orientation and class performance oriented climates were positively associated with feelings of being on the fringe of ethnic identity, and with lack of desire to interact with members of other ethnic groups.ConclusionsThe present findings encourage the conduct of intervention studies emphasizing task orientation and decreasing ego orientation to promote mutual respect among ethnicities and acculturation from the larger culture.