Association between support of basic psychological needs and stress response as mediated by motivation for solitude.

This study examined the relationship between not self-determined / self-determined solitude and stress responses, as well as the effect of supporting / thwarting of basic psychological needs. The sample consisted of 606 Japanese people aged 20 years and older. We used a cross-sectional survey to measure their motivations for solitude, supporting / thwarting of basic psychological needs, and stress responses. Not self-determined solitude was negatively correlated with supporting of basic psychological needs and positively correlated with thwarting of basic psychological needs. In addition, a cutoff score of 16 for not self-determined solitude was found to be optimal for identifying individuals with a high stress response. Mediation analysis revealed that supporting / thwarting of basic psychological needs has direct effects on stress responses and indirect effects mediated by not self-determined solitude. These findings suggest that fostering environments that support basic psychological needs of autonomy, competence, and relatedness can alleviate not self-determined solitude and reduce stress responses.

Auditory startle reflex inhibited by preceding self-action.

A startle reflex to a startle pulse is inhibited when preceded by a prestimulus. We introduced a key-press action (self-action) or an 85 dB noise burst as a prestimulus, followed by a 115 dB noise burst as a startle pulse. We manipulated temporal offsets between the prestimulus and the startle pulse from 30-1,500 ms to examine whether self-action modulates the startle reflex and the temporal properties of the modulatory effect. We assessed eyeblink reflexes by electromyography. Both prestimuli decreased reflexes compared to pulse-alone trials. Moreover, the temporal windows of inhibition were different between the types of prestimuli. A faster maximal inhibition and narrower temporal window in self-action trials suggest that preceding self-action inhibits the startle reflex and allows prediction of the coming pulse in different ways from auditory prestimuli.

Combined effects of perceptual grouping cues on object representation: evidence from motion-induced blindness.

We investigated the combined effects of perceptual grouping cues (proximity and contour closure/proximity and orientation similarity) on object representation, using motion-induced blindness, a phenomenon in which salient visual stimuli perceptually disappear when surrounded by moving patterns. We presented as visual targets two stimuli in which a solid square was embedded in an outlined square. Participants reported whether the targets disappeared independently or simultaneously. The results showed that a relatively high proximity cue (with a 0.2-deg separation between the targets) modulated the perceptions of the independent or simultaneous disappearances of targets, regardless of other grouping cues. The contour closure cue modulated these disappearances in the 0.4- to 0.8-deg separations. Finally, the orientation similarity cue began to modulate these disappearances in the 0.6- to 0.8-deg separations. We suggest that the separation between the visual stimuli modulates the combined effects of perceptual grouping cues on complete object representation.