Keeping in touch with one’s self: multisensory mechanisms of self-consciousness

In the paper

“No significant effects (p>0.05) of stroking type were found for self-location – the size of the drift in self-location did not differ for synchronous and asynchronous conditions.”

In the paper

“the CCE was significantly larger for the same side compared to the different side visual presentation when the body was visible (t1,10 = 3.22; p = 0.009) but not when the body was not visible (t1,10 = 0.83; p>0.05).”

In the paper

“The ANOVA did not reveal any significant main effects: stroking type (F1, 8 = 0.04, p = 0.846); side (F1, 8 = 0.01, p = 0.921); congruency (F1, 8 = 4.43, p = 0.068), or any significant interactions: stroking type×side (F1, 8 = 1.57, p = 0.246); stroking type×congruency (F1, 8 = 0.60, p = 0.460); side×congruency (F1, 8 = 0.452, p = 0.520); stroking type×side×congruency (F1, 8 = 1.17, p = 0.311).”

In the paper

“The ANOVA revealed a significant main effect of side (F1,12 = 9.10; p = 0.011), congruency (F1,12 = 15.80; p = 0.002), a significant interaction between side and congruency (F1,12 = 13.40; p = 0.003), and crucially, a significant three-way interaction between stroking type, side and congruency (F1,12 = 11.30; p = 0.006).”

In the paper

“For the questionnaire data, there was a significant difference between ratings of the self-identification question (“I felt as if the object was my body“) for the synchronous and asynchronous object blocks (z = 2.20; p = 0.03), however the ratings were barely, or not even positive (4.1 for synchronous and 2.9 for synchronous on a scale where rating 4 is neither positive nor negative, i.e. ‘zero’).”

In the paper

“In the synchronous condition the subjects showed a mean drift in self-location of 8.1 cm towards the virtual body, whereas in the asynchronous condition the mean drift was 0.1 cm”

In the paper

“Our second prediction was not confirmed: stroking (synchronous versus asynchronous) neither modulated the CCE, nor did it modify self-location or self-identification.”

In the paper

“Second, full body CCEs are larger during synchronous stroking than during asynchronous stroking of one's back, and depend on the temporal delay between the vibro-tactile and LED stimuli.”

In the paper

“we found that the CCE is present for the full body, and is larger when subjects see their body (as compared to when they do not see their body).”

In the paper

“Analysis of the error rates for the object control showed that error rates were lower for the asynchronous condition than the synchronous condition: there was a significant main effect of stroking type (F1, 8 = 5.61, p = 0.045).”

In the paper

“Third, both full body CCEs and measures of bodily self-consciousness are modulated by visuo-tactile stimulation (type of stroking): In the synchronous stroking condition CCEs are larger, the drift towards the seen body is greater and the questionnaire ratings of self- identification with the seen body are higher compared to in the asynchronous condition.”

In the paper

“The error rates showed a similar pattern of modulation by congruency and side. There was a significant main effect of congruency (F1,12 = 21.69; p = 0.001) and a significant interaction between side and congruency (F1,12 = 60.46; p = 0.000).”

In the paper

“We replicated the previous result for the ‘body’ condition in this new sample of subjects, i.e. the effects confirmed those of study 2: during synchronous stroking the CCE was significantly larger when the light appeared on the same side as the tactile stimulus compared to when it appeared on the different side (t1,8 = 2.60; p = 0.031), whereas the CCE during asynchronous stroking did not differ”

In the paper

“Planned comparisons between same and different side CCEs for synchronous and asynchronous conditions revealed that the CCE was significantly larger for the same side than different side in the synchronous condition (t1,12 = 4.01; p = 0.002), but not in the asynchronous condition (t1,12 = 2.17; p>0.05).”

In the paper

“Such effects were absent when the stimulus display did not show the subject's body, and when an object was viewed in the place of the body, even though the visual stimuli (LEDs) were still visible and in the same spatial configuration.”

In the paper

“The mean RTs and the drift (self-location) measures (calculated relative to initial position = 0) were normally distributed (Kolmogorov-Smirnov test for normality)”

In the paper

“Self-identification with the seen body and other phenomenological aspects were assessed at the end of each block by a questionnaire adapted from [18]; see Table 1.”

What the sources say

• Not checked yetcites [18] B Lenggenhager, 2007, Video Ergo Sum: Manipulating Bodily Self-Consciousness., Science source

In the paper

“The order of blocks was counterbalanced across subjects.”

In the paper

“When the ‘felt stroking’ on the back of the body was congruent with the ‘seen stroking’ on the ‘virtual’ body, subjects showed higher degrees of ownership (or self-identification) for the virtual body, and mislocalized their self to a position outside their bodily borders.”

What the sources say

• Not checked yetcites [18] B Lenggenhager, 2007, Video Ergo Sum: Manipulating Bodily Self-Consciousness., Science source

In the paper

“Two subjects were excluded from the analyses of study 1 because of chance-level performance in some conditions.”

In the paper

“As a result an average of 4.8% of trials per subject were discarded.”

In the paper

“The stimulus onset asynchrony (SOA) of 33 msec in study 1 was chosen based on previous studies on CCEs [30], [33] which reported maximal CCEs for an SOA of ∼30–100 msec.”

What the sources say

• Not checked yetcites [30] C Spence, 2004, Spatial constraints on visual-tactile cross-modal distractor congruency effects Cognitive, Affective and Behavioral Neuroscience
• Not checked yetcites [33] DI Shore, 2006, Temporal aspects of the visuotactile congruency effect., Neuroscience Letters source

In the paper

“A complex range of temporal, spatial (and cognitive) factors determines the weighting of each unisensory input during multisensory integration [35]–[37].”

What the sources say

• Not checked yetcites [35]–[37]

In the paper

“It is therefore possible that the particular combination of visual and tactile signals that were present in the experimental conditions in study 1 may have affected the visuo-tactile integration involved in the computation of self-location.”

In the paper

“This may have been because in the present set-up we added a second visuo-tactile mismatch (LED versus vibration) to the visuo-tactile mismatch already present due to stroking, thus the stimuli in the congruency task may have interfered with mechanisms related to self-location and self-identification.”

In the paper

“This side effect is likely to be a due to a change in the spatial perceptual representations because if the touch is represented as being closer in space to where the body (and LEDs) are seen then we would expect the difference between same and different side CCEs to be larger.”

In the paper

“The present data show that the previously described [17], [18], [25], [27] changes in self-location and self-identification are - under certain experimental conditions - associated with changes in the CCE, and hence with changes in the mapping of tactile stimuli.”

What the sources say

• Not checked yetcites [17] B Lenggenhager, 2009, Spatial aspects of bodily self-consciousness. source
• Not checked yetcites [18] B Lenggenhager, 2007, Video Ergo Sum: Manipulating Bodily Self-Consciousness., Science source
• Not checked yetcites [25], [27]

In the paper

“We argue that when the LED-vibro-tactile stimuli were made more asynchronous (by introducing the larger SOA), this may have influenced the differential weighting of all visual and tactile stimuli present, and therefore have affected how the felt stroking and seen stroking were integrated.”

In the paper

“The difference in CCEs we report can only show that tactile and spatial stimuli are perceived as being closer to each other (in the synchronous condition) – this finding cannot by itself show whether it is touch or vision that is remapped.”

In the paper

“It is well known that multisensory integration is strongly influenced by the temporal relations between stimuli [33], [35]–[37].”

What the sources say

• Not checked yetcites [33] DI Shore, 2006, Temporal aspects of the visuotactile congruency effect., Neuroscience Letters source
• Not checked yetcites [35]–[37]

In the paper

“The self-related aspects of the CCE appear to be not simply an effect of seeing a body, but of identifying with the seen body, and having an altered self-location (biased towards the spatial location at which the body is seen).”

In the paper

“In conclusion, the present data reveal full body-related CCEs, and ‘self-related’ CCEs, the latter demonstrating that the magnitude of the CCE is associated with ‘what I experience as my body’ and ‘where I experience my body to be’.”

In the paper

“The present study reveals that systematic alterations in the mapping of tactile stimuli occur in the full body illusion, and thus establishes CCE magnitude as an online performance proxy for subjective changes in bodily self-consciousness.”

In the paper

“Firstly, CCEs were associated with changes in self-identification (and thus more global changes than changes in self-attribution measured in the RHI).”