Visual, somatosensory, and perspectival cues normally provide congruent information about where the self is experienced. Separating those cues by virtual reality techniques, recent studies found that self-location was systematically biased to where a visual–tactile event was seen. Here we developed a novel, repeatable and implicit measure of self-location to compare and extend previous protocols. We investigated illusory self-location and associated phenomenological aspects in a lying body position that facilitates clinically observed abnormal self-location . The results confirm that the self is (...) located to where touch is seen. This leads to either predictable lowering or elevation of self-localization, and the latter was accompanied by sensations of floating, as during out-of-body experiences. Using a novel measurement we show that the unitary and localized character of the self can be experimentally separated from both the origin of the visual perspective and the location of the seen body, which is compatible with clinical data. (shrink)

We investigated how motor agency in the voluntary control of body movement influences body awareness. In the Rubber Hand Illusion , synchronous tactile stimulation of a rubber hand and the participant’s hand leads to a feeling of the rubber hand being incorporated in the participant’s own body. One quantifiable behavioural correlate of the illusion is an induced shift in the perceived location of the participant’s hand towards the rubber hand. Previous studies showed that the induced changes in body awareness are (...) local and fragmented: the proprioceptive drift is largely restricted to the stimulated finger. In the present study, we investigated whether active and passive movements, rather than tactile stimulation, would lead to similarly fragmented body awareness. Participants watched a projected image of their hand under three conditions: active finger movement, passive finger movement, and tactile stimulation. Visual feedback was either synchronous or asynchronous with respect to stimulation of the hand. A significant overall RHI, defined as greater drifts following synchronous than asynchronous stimulation, was found in all cases. However, the distribution of the RHI across stimulated and non-stimulated fingers depended on the kind of stimulation. Localised proprioceptive drifts, specific to the stimulated finger, were found for tactile and passive stimulation. Conversely, during active movement of a single digit, the proprioceptive drifts were not localised to that digit, but were spread across the whole hand. Whereas a purely proprioceptive sense of body-ownership is local and fragmented, the motor sense of agency integrates distinct body-parts into a coherent, unified awareness of the body. (shrink)

Although philosophical approaches to the self are diverse, several of them are relevant to cognitive science. First, the notion of a 'minimal self', a self devoid of temporal extension, is clarified by distinguishing between a sense of agency and a sense of ownership for action. To the extent that these senses are subject to failure in pathologies like schizophrenia, a neuropsychological model of schizophrenia may help to clarify the nature of the minimal self and its neurological underpinnings. Second, there is (...) good evidence to suggest that although certain aspects of the minimal self are primitive and embodied, other aspects may be accessed only in reflective consciousness. Employing a modified concept of the minimal self, it may be possible to construct a robotic form of non-conscious self-reference that depends on an interaction between the robotic body and its environment. In contrast to the minimal self, the narrative self involves continuity over time and is directly relevant to discussions of memory and personal identity. There is growing consensus among philosophers and cognitive scientists about the importance of narrative and its relation to episodic memory and left-hemisphere functions. There are, however, at least two different views of how the narrative self is structured. On one model it is nothing more than an abstract point. On a more extended view, proposed here, the self is a rich amalgam of narratives that allows for the equivocations, contradictions, and self-deceptions of personal life. Even in this case, however, neurocognitive models contribute to our understanding of how narrative identity is structured. (shrink)

Genes adjacent to species-specific loci are 6.2% older than genes adjacent to other dynamic loci (P < 10−2 by randomization; gray bars in Fig. 3); thus, species-specific genes are not randomly distributed but are found preferentially in the older regions, indicating that the incipient Escherichia and Salmonella lineages continued to participate in recombination at loci unlinked to lineage-specific genes.

Self-location—the sense of where I am in space—provides an experiential anchor for one's interaction with the environment. In the studies of full-body illusions, many researchers have defined self-location solely in terms of body-location—the subjective feeling of where my body is. Although this view is useful, there is an issue regarding whether it can fully accommodate the role of 1PP-location—the sense of where my first-person perspective is located in space. In this study, we investigate self-location by comparing body-location and 1PP-location: using (...) a head-mounted display (HMD) and a stereo camera, the subjects watched their own body standing in front of them and received tactile stimulations. We manipulated their senses of body-location and 1PP-location in three different conditions: the participants standing still (Basic condition), asking them to move forward (Walking condition), and swiftly moving the stereo camera away from their body (Visual condition). In the Walking condition, the participants watched their body moving away from their 1PP. In the Visual condition, the scene seen via the HMD was systematically receding. Our data show that, under different manipulations of movement, the spatial unity between 1PP-location and body-location can be temporarily interrupted. Interestingly, we also observed a “double-body effect.” We further suggest that it is better to consider body-location and 1PP-location as interrelated but distinct factors that jointly support the sense of self-location. (shrink)