Assessing the neural correlates of self-enhancement bias: a transcranial magnetic stimulation study

Abstract

Considerable research has focused on overly positive self-perceptions (self-enhancement), and yet little is known about the underlying neural mechanisms. The present study sought to assess the neural correlates of self-enhancement by applying Transcranial Magnetic Stimulation (TMS) to three brain regions. Twelve participants rated their best friend, as well as the self on a set of desirable or undesirable traits while TMS pulses were delivered in a virtual lesion manner. During the baseline condition (Sham TMS), participants produced more desirable and fewer undesirable ratings for themselves as compared to their best friend, showing self-enhancement. Compared to Sham TMS, TMS delivered to the Medial Prefrontal Cortex (MPFC) reduced self-enhancement whereas TMS delivered to the Supplementary Motor Area (SMA) and the precuneus did not. Together, these findings suggest that the MPFC may influence self-enhancement.

Coherence in consciousness: Paralimbic gamma synchrony of self‐reference links conscious experiences

“…The gamma band synchronization occurred preferentially as a function of selfreference. This preference suggests a role for paralimbic gamma synchrony in self-reference and is in agreement with the specificity of the paralimbic circuitry for self-reference documented elsewhere with transcranial magnetic stimulation (TMS) [Kwan et al, 2007;Lou et al, 2004].…”

“…It is concluded that widely different conscious experiences are linked by increased synchrony in a paralimbic circuitry which has previously been shown to be critical for self-reference [Kwan et al, 2007;Lou et al, 2004]. The synchronization is preferential for self-reference in the gamma range.…”

“…The functional integrity of medial parietal cortex is critical for extended self-awareness. This has been shown by TMS, targeting precuneus, to transiently disrupt the normal function of this region [Kwan et al, 2007;Lou et al, 2004]. Thalamus, including intralaminar nuclei, medial pulvinar, and the dorso-medial nuclei, is connected with paralimbic cortical regions by reciprocal, reentrant connections [Tononi and Edelman, 2000].…”

“…The concept is further supported by studies with transcranial magnetic stimulation, showing that activity in this circuitry is critical for self-awareness and retrieval of memories of personal experiences, i.e. episodic memory [Kwan et al, 2007;Lou et al, 2004]. Episodic memory retrieval is by definition an indispensable component of the more complex forms of self-awareness and consciousness with a coherent self across time, which are described in various terms such as extended self [Neisser, 1988], autonoetic consciousness [Gardiner, 2001;Tulving, 1985], or narrative self [Gallagher, 2000].…”

Neural activation pattern in self-deceivers

“…This self generally operate at unconscious level and is probably diffi cult in introspection, so it might be possible to measure this phenomena indirectly (Greenwald & Banaji, 1995). As previous studies have not found any direct measure to evaluate the neural correlates involve in self (Kwan, Barrios, Ganis, Gorman, Lange, Kumar, Shepard & Keenan, 2007). In the present study, with this theoretical presumption, we applied semantic and episodic memory task to see the role of working memory in self-deception condition.…”