The effect of deception on motor cortex excitability

Abstract

Although a number of recent neuroimaging studies have examined the relationship between the brain and deception, the neurological correlates of deception are still not well understood. The present study sought to assess differences in cortical excitability during the act of deception by measuring motor evoked potentials (MEPs) during transcranial magnetic stimulation (TMS). Sports fanatics and low-affiliation sports fans were presented with preferred and rival team images and were asked to deceptively or honestly identify their favored team. Hemispheric differences were found including greater excitability of the left motor cortex during the generation of deceptive responses. In contrast to current physiological measures of deception, level of arousal was not found to differentiate truthful and deceptive responses. The results are presented in terms of a complex cognitive pattern contributing to the generation of deceptive responses.

Corticospinal Excitability during a Perspective Taking Task as Measured by TMS-Induced Motor Evoked Potentials

“…When they thought the left hand part of the music was being played by another person, the MEPs in the left arm were greater, and MEPs increased as the participant's empathy increased [75]. Further, previous work by our lab demonstrated that adopting another's perspective (e.g., pretending to be a fan of an opposing sports team) led to greater left motor cortex/right hand MEPs [76].…”

Investigating Deception and Deception Detection with Brain Stimulation Methods

“…Two additional studies used single-pulse TMS to probe motor cortex excitability during deception (Duzel et al, 2003;Kelly et al, 2009). …”

“…Finally, two studies employed single-pulse TMS to probe the excitability of primary motor cortex during deceptive behaviour (Kelly et al, 2009;Lo, Fook-Chong, & Tan, 2003) since a number of neuroimaging studies have reported stronger motor cortex activation (especially in the left hemisphere) to deceptive than honest responses (Ganis, Kosslyn, Stose, Thompson, & Yurgelun-Todd, 2003;Kozel et al, 2005;Langleben et al, 2002;Spence et al, 2001Spence et al, , 2004. In the first study (Lo et al, 2003), MEPs were recorded from the participants' left or right thumb in response to single TMS pulses delivered to the contralateral primary motor cortex (in different blocks).…”

“…Results showed an increase in excitability (larger MEPs) after stimulation of both left and right primary motor cortex in the deceptive conditions, suggesting that primary motor cortex is functionally involved in generating deceptive responses. A similar study focused on the laterality of primary motor cortex involvement and used emotionally stronger materials by asking people to tell the truth or lie about whether they liked items belonging to their favourite (vs. least favourite) sports team (Kelly et al, 2009). Results showed higher excitability for deceptive than honest responses in left motor cortex but a trend in the opposite direction in right motor cortex.…”

Corticospinal Excitability During a Perspective Taking Task as Measured by TMS-induced Motor Evoked Potentials

“…When they thought the left hand part of the music was being played by another person, the MEPs in the left arm were greater, and MEPs increased as the participant's empathy increased (Novembre, Ticini, Schütz-Bosbach, & Keller, 2012). Further, previous work by our lab demonstrated that adopting another's perspective (e.g., pretending to be a fan of an opposing sports team) led to greater left motor cortex/right hand MEPs (Kelly et al, 2009). Centered on first-person perspective, a number of researchers employed TMS induced motor-evoked potentials (MEPs) to measure lateralized cortical excitability during the presentation of self-descriptive adjectives (Molnar-Szakacs, .…”