title: Laser-Evoked Vertex Potentials Predict Defensive Motor Actions.
abstract: The vertex potential is the largest response that can be recorded in the electroencephalogram of an awake, healthy human. It is elicited by sudden and intense stimuli, and is composed by a negative-positive deflection. The stimulus properties that determine the vertex potential amplitude have been well characterized. Nonetheless, its functional significance remains elusive. The dominant interpretation is that it reflects neural activities related to the detection of salient stimuli. However, given that threatening stimuli elicit both vertex potentials and defensive movements, we hypothesized that the vertex potential is related to the execution of defensive actions. Here, we directly compared the salience and motoric interpretations by investigating the relationship between the amplitude of laser-evoked potentials (LEPs) and the response time of movements with different defensive values. First, we show that a larger LEP negative wave (N2 wave) predicts faster motor response times. Second, this prediction is significantly stronger when the motor response is defensive in nature. Third, the relation between the N2 wave and motor response time depends not only on the kinematic form of the movement, but also on whether that kinematic form serves as a functional defense of the body. Therefore, the N2 wave of the LEP encodes key defensive reactions to threats.
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK.
authors.forename: M
authors.initials: M
authors.lastname: Moayedi
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK School of Medical Imaging, Tianjin Medical University, Tianjin 300203, China.
authors.forename: M
authors.initials: M
authors.lastname: Liang
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK.
authors.forename: A L
authors.initials: AL
authors.lastname: Sim
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK Key Laboratory of Cognition and Personality (Ministry of Education) and School of Psychology, Southwest University, Chongqing 400715, China.
authors.forename: L
authors.initials: L
authors.lastname: Hu
authors.affiliation: Institute of Cognitive Neuroscience, Department of Psychology, University College London, London WC1N 3AR, UK.
authors.forename: P
authors.initials: P
authors.lastname: Haggard
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, UK.
authors.forename: G D
authors.initials: GD
authors.lastname: Iannetti
mesh_terms: D000328:Adult; D001362:Avoidance Learning / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D004558:Electric Stimulation; D004569:Electroencephalography; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006225:Hand; D006801:Humans; D007834:Lasers; D008297:Male; D059225:Nociception / Q000502:physiology*; D010147:Pain Measurement; D011930:Reaction Time; D055815:Young Adult
keywords: agency; defense; event-related potentials; saliency; sensorimotor integration; threat detection