title: Nociceptive-Evoked Potentials Are Sensitive to Behaviorally Relevant Stimulus Displacements in Egocentric Coordinates.
abstract: Feature selection has been extensively studied in the context of goal-directed behavior, where it is heavily driven by top-down factors. A more primitive version of this function is the detection of bottom-up changes in stimulus features in the environment. Indeed, the nervous system is tuned to detect fast-rising, intense stimuli that are likely to reflect threats, such as nociceptive somatosensory stimuli. These stimuli elicit large brain potentials maximal at the scalp vertex. When elicited by nociceptive laser stimuli, these responses are labeled laser-evoked potentials (LEPs). Although it has been shown that changes in stimulus modality and increases in stimulus intensity evoke large LEPs, it has yet to be determined whether stimulus displacements affect the amplitude of the main LEP waves (N1, N2, and P2). Here, in three experiments, we identified a set of rules that the human nervous system obeys to identify changes in the spatial location of a nociceptive stimulus. We showed that the N2 wave is sensitive to: (1) large displacements between consecutive stimuli in egocentric, but not somatotopic coordinates; and (2) displacements that entail a behaviorally relevant change in the stimulus location. These findings indicate that nociceptive-evoked vertex potentials are sensitive to behaviorally relevant changes in the location of a nociceptive stimulus with respect to the body, and that the hand is a particularly behaviorally important site.
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom; Faculty of Dentistry, University of Toronto, Toronto, M5G 1G6 Canada.
authors.forename: M
authors.identifier: 0000-0002-7324-2540
authors.initials: M
authors.lastname: Moayedi
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom; Department of Neurology and Psychiatry, Sapienza University of Rome, Rome 00185, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Di Stefano
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London , London WC1E 6BT, United Kingdom.
authors.forename: M T
authors.initials: MT
authors.lastname: Stubbs
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London , London WC1E 6BT, United Kingdom.
authors.forename: B
authors.initials: B
authors.lastname: Djeugam
authors.affiliation: Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom; School of Medical Imaging and Tianjin Key Laboratory of Functional 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, United Kingdom.
authors.forename: G D
authors.initials: GD
authors.lastname: Iannetti
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000502:physiology*; D004569:Electroencephalography; D005073:Evoked Potentials, Somatosensory; D005260:Female; D005528:Foot / Q000502:physiology; D006225:Hand / Q000502:physiology; D006358:Hot Temperature; D006801:Humans; D007834:Lasers; D008297:Male; D059225:Nociception / Q000502:physiology*; D058748:Pain Perception / Q000502:physiology*; D010812:Physical Stimulation / Q000379:methods; D011601:Psychophysics; D012815:Signal Processing, Computer-Assisted; D055815:Young Adult
keywords: EEG; attentional reorientation; body schema; laser-evoked potentials (LEPs); nociception; saliency; threat detection; vertex potential