Abstract
Neural circuits associated with response conflict are active during deception. Here we use transcranial
magnetic stimulation to examine for the firsttime whether competing responses in primary motor cortex
can be used to detect lies. Participants used their little finger or thumb to respond either truthfully or
deceitfully regarding facial familiarity. Motor-evoked-potentials (MEPs) from muscles associated with
both digits tracked the development of each motor plan. When preparing to deceive, the MEP of the
non-responding digit (i.e. the plan corresponding to the truth) exceeds the MEP of the responding digit
(i.e. the lie), whereas a mirror-reversed pattern occurs when telling the truth. This give away response
conflict interacts with the time of stimulation during a speeded reaction period. Lies can even activate
digit-specific cortical representations when only verbal responses are made. Our findings support neurobiological
models which blend cognitive decision-making with motor programming, and suggest a novel
index for discriminating between honest and intentionally false facial recognition.
Original language | English |
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Pages (from-to) | 495-502 |
Journal | Biological Psychology |
Volume | 89 |
Issue number | 2 |
Early online date | 6 Jan 2012 |
DOIs | |
Publication status | Published - 29 Feb 2012 |