The self in action effects: selective attenuation of self-generated sounds

The immediate experience of self-agency, that is, the experience of generating and controlling our actions, is thought to be a key aspect of selfhood. It has been suggested that this experience is intimately linked to internal motor signals associated with the ongoing actions. These signals should lead to an attenuation of the sensory consequences of one’s own actions and thereby allow classifying them as self-generated. The discovery of shared representations of actions between self and other, however, challenges this idea and suggests similar attenuation of one’s own and other’s sensory action effects.Here, we tested these assumptions by comparing sensory attenuation of self-generated and observed sensory effects. More specifically, we compared the loudness perception of sounds that were either self-generated, generated by another person or a computer. In two experiments, we found a reduced perception of loudness intensity specifically related to self-generation. Furthermore, the perception of sounds generated by another person and a computer did not differ from each other. These findings indicate that one’s own agentive influence upon the outside world has a special perceptual quality which distinguishes it from any sort of external influence, including human and non-human sources. This suggests that a real sense of self-agency is not a socially shared but rather a unique and private experience.     

Effects of mental stressors on mitogen induced lymphocyte responses in the laboratory

Abstract

There is considerable evidence from naturalistic studies that psychosocial stressors affect human immune function. To achieve control over factors that could bias naturalistic studies, laboratory stressors developed by cardiovascular researchers were tested to determine if they affected immune function. Thirty volunteer students were exposed to 20 minutes of mental tasks. Psychophysiological indices (heart rate, blood pressure, skin conductance) and subjective responses were monitored prior to, during, and 1-hour after the tasks, blood, samples for immunological analyses were also drawn at these times. Thirteen subjects who were not exposed to the tasks served as controls. Subjects exposed to the tasks showed increased levels of subjective distress and increased psychophysiologic responses (except diastolic blood pressure) during the tasks. Relative to controls, stressed subjects had reduced lymphocyte proliferative responses to classic T cell mitogens both immediately after and 1-hour after the tasks were found in whole blood cultures, although responses of isolated lymphocytes were not significantly affected. There were only marginal differences in whole blood mitogen responses for stressed subjects with low versus high autonomic reactions to the stressor. These results support an emerging view that the immune system is sensitive to brief stressors and that laboratory models may be useful for exploring stress-induced changes in immune function.     

Self-conscious emotions and depression: rumination explains why shame but not guilt is maladaptive

Feelings of shame and guilt are factors associated with depression. However, studies simultaneously investigating shame and guilt suggest that only shame has a strong unique effect, although it is not yet clear which psychological processes cause shame and not shame-free guilt to be related to depression. The authors hypothesized that shame, in contrast to guilt, elicits rumination, which then leads to depression. Therefore, in this study we investigated event-related shame and guilt, event-related rumination, and depression among 149 mothers and fathers following family breakup due to marital separation. Data were analyzed using latent variable modeling. The results confirm that shame but not guilt has a strong unique effect on depression. Moreover, the results show that the effect of shame is substantially mediated by rumination. The results are discussed against the background of self-discrepancies and self-esteem.     

Recognition of biological motion from blurred natural scenes

Biological-motion perception can be regarded as a template-matching process. We are concerned with the visual cues in this template. Biological-motion perception is usually studied with point-light displays similar to the point-light displays invented by Johansson (1973 Perception and Psychophysics 14 201 - 211). These stimuli are in some ways abstract. In order to use more natural stimuli, we recorded movies of different actions in natural scenes. By blurring the scenes we modified the visual cues, particularly the local form and motion information. Observers were asked to identify the action portrayed. Our results demonstrate that templates for biological-motion recognition combine global form and motion cues. Reductions of local form and local motion information by blurring can be compensated by global form change and global motion. Local motion information is also used for segmentation.     

Gestural acquisition in great apes: the Social Negotiation Hypothesis

Animal Cognition - Scientific interest in the acquisition of gestural signalling dates back to the heroic figure of Charles Darwin. More than a hundred years later, we still know relatively little...