Who you gonna call? TMS-induced inhibition of the left premotor cortex acts as a Bayesian Ghost Buster by altering illusory social perception
Communicative actions from one person are used to predict another persons response. However, in some cases, these predictions can outweigh the processing of sensory information and lead to illusory social perception such as seeing two people interact, although only one is present (i.e., seeing a Bayesian ghost). We applied either inhibitory brain stimulation over the left premotor cortex (i.e., real TMS) or sham TMS. Then, participants indicated the presence or absence of a masked agent that followed a communicative or individual gesture of another agent. As expected, participants had more false alarms (i.e., Bayesian ghosts) in the communicative than individual condition in the sham TMS session and this difference between conditions vanished after real TMS. In contrast to our hypothesis, the number of false alarms increased (rather than decreased) after real TMS. These pre-registered findings confirm the significance of the premotor cortex for social action predictions and illusory social perception. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=145 SRC="FIGDIR/small/526257v2_ufig1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@1b5812corg.highwire.dtl.DTLVardef@1338411org.highwire.dtl.DTLVardef@123b84eorg.highwire.dtl.DTLVardef@192a4b_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LISocial predictions can outweigh sensory information and lead to illusory perception C_LIO_LIPremotor cortex is linked to the illusory social perception of a Bayesian ghost C_LIO_LITMS over premotor cortex modulates how social predictions influence our perception C_LI