title: Hypnotic modulation of pain perception and of brain activity triggered by nociceptive laser stimuli.
abstract: BACKGROUND
  Neuroimaging studies indicate that hypnotic suggestions of increased and decreased pain intensity and unpleasantness may modulate somatosensory and cingulate cortex activity, respectively.
  
  
  METHODS
  Using a within subject design and a strict subject selection procedure, we tested in High (Highs) and Low (Lows) hypnotically suggestible individuals whether hypnotic suggestions of sensory and affective hypoalgesia or hyperalgesia differentially affected subjective ratings of laser-induced pain and nociceptive-related brain activity in the time- and time-frequency domain.
  
  
  RESULTS
  Hypnotic modulation of pain intensity and unpleasantness affected subjective ratings of laser-induced pain only in Highs. Such modulation was more specific for unpleasantness manipulation and more evident for suggestions of hyperalgesia. Importantly, Highs and Lows showed increase and decrease of P2a and P2b wave amplitudes and gamma band power, respectively.
  
  
  CONCLUSIONS
  Hypnotic suggestions exerted a top-down modulatory effect on both evoked and induced-cortical brain responses triggered by selective nociceptive laser inputs. Furthermore, correlation analyses indicated that gamma power modulation and suggestions of hyperalgesia may reflect the process of allocating control resources to salient and threatening sensory-affective dimensions of pain.
authors.affiliation: Sapienza Università di Roma, Dipartimento di Psicologia, Italy. elia.valentini@uniroma1.it
authors.forename: Elia
authors.initials: E
authors.lastname: Valentini
authors.forename: Viviana
authors.initials: V
authors.lastname: Betti
authors.forename: Li
authors.initials: L
authors.lastname: Hu
authors.forename: Salvatore M
authors.initials: SM
authors.lastname: Aglioti
mesh_terms: D000698:Analgesia; D000704:Analysis of Variance; D001921:Brain / Q000502:physiology*; D003344:Cortical Synchronization; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D007839:Functional Laterality; D006358:Hot Temperature; D006801:Humans; D006990:Hypnosis; D007834:Lasers; D008297:Male; D059225:Nociception / Q000502:physiology*; D010147:Pain Measurement; D058748:Pain Perception / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology; D010812:Physical Stimulation; D013404:Suggestion; D055815:Young Adult