Hypnotic suggestions cognitively penetrate tactile perception through top-down modulation of semantic contents

• Published in: Scientific reports Vol. 13; no. 1; pp. 6578 - 13
• Main Authors: Markmann, Marius, Lenz, Melanie, Höffken, Oliver, Steponavičiūtė, Agnė, Brüne, Martin, Tegenthoff, Martin, Dinse, Hubert R., Newen, Albert
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 21.04.2023; Nature Publishing Group; Nature Portfolio
• Subjects: 631/378; 631/477; 692/308; 692/617; Cognition; Cortex (frontal); Finger; Frequency dependence; Humanities and Social Sciences; Hypnosis; Information processing; multidisciplinary; Perception; Science; Science (multidisciplinary); Semantics; Sensory neurons; Somatosensory cortex; Somatosensory Cortex - physiology; Somatosensory evoked potentials; Spatial discrimination; Suggestion; Synchronization; Tactile discrimination; Tactile perception; Touch; Touch Perception - physiology
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-023-33108-z

Perception is subject to ongoing alterations by learning and top-down influences. Although abundant studies have shown modulation of perception by attention, motivation, content and context, there is an unresolved controversy whether these examples provide true evidence that perception is penetrable by cognition. Here we show that tactile perception assessed as spatial discrimination can be instantaneously and systematically altered merely by the semantic content during hypnotic suggestions. To study neurophysiological correlates, we recorded EEG and SEPs. We found that the suggestion “your index finger becomes bigger” led to improved tactile discrimination, while the suggestion “your index finger becomes smaller” led to impaired discrimination. A hypnosis without semantic suggestions had no effect but caused a reduction of phase-locking synchronization of the beta frequency band between medial frontal cortex and the finger representation in somatosensory cortex. Late SEP components (P80–N140 complex) implicated in attentional processes were altered by the semantic contents, but processing of afferent inputs in SI remained unaltered. These data provide evidence that the psychophysically observed modifiability of tactile perception by semantic contents is not simply due to altered perception-based judgments, but instead is a consequence of modified perceptual processes which change the perceptual experience.