title: Watching what's coming near increases tactile sensitivity: An experimental investigation.
abstract: During medical examinations, doctors regularly investigate a patient's somatosensory system by approaching the patient with a medical device (e.g. Von Frey hairs, algometer) or with their hands. It is assumed that the obtained results reflect the true capacities of the somatosensory system. However, evidence from crossmodal spatial research suggests that sensory experiences in one modality (e.g. touch) can be influenced by concurrent information from other modalities (e.g. vision), especially near the body (i.e. in peripersonal space). Hence, we hypothesized that seeing someone approaching your body could alter tactile sensitivity in that body-part. In the In Vivo Approaching Object (IVAO) paradigm, participants detected and localized threshold-level vibrotactile stimuli administered on the left of right hand (=tactile targets). In Experiment 1, this was always preceded by the experimenter approaching the same (congruent trials) or the other (incongruent trials) hand with a pen (=visual cue). In Experiment 2, a condition was added in which a point further away from the hands (also left vs. right) was approached. Response Accuracy was calculated for congruent and incongruent trials (Experiment 1 & 2) and compared between the close and far condition (Experiment 2). As expected, Response Accuracy was higher in congruent trials compared to incongruent trials, but only near the body. As a result, evidence was found for a crossmodal interaction effect between visual and tactile information in peripersonal space. These results suggest that somatosensory evaluations-both medical or research-based-may be biased by viewing an object approaching the body.
authors.affiliation: Department of Experimental-Clinical and Health Psychology, Ghent University, Henri Dunantlaan 2, 9000 Gent, Belgium. Electronic address: Livdrbie.VanderBiest@Ugent.be.
authors.forename: Lien
authors.initials: L
authors.lastname: Van der Biest
authors.affiliation: Institute of Neuroscience, Université catholique de Louvain, Avenue Mounier 53 bte B1.53.04, 1200 Brussels, Belgium.
authors.forename: Valéry
authors.initials: V
authors.lastname: Legrain
authors.affiliation: Department of Experimental-Clinical and Health Psychology, Ghent University, Henri Dunantlaan 2, 9000 Gent, Belgium.
authors.forename: Annick De
authors.initials: AD
authors.lastname: Paepe
authors.affiliation: Department of Experimental-Clinical and Health Psychology, Ghent University, Henri Dunantlaan 2, 9000 Gent, Belgium.
authors.forename: Geert
authors.initials: G
authors.lastname: Crombez
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention; D005260:Female; D006225:Hand; D006801:Humans; D008297:Male; D009039:Motion Perception; D010812:Physical Stimulation; D011601:Psychophysics; D012649:Self Concept; D012684:Sensory Thresholds; D012938:Social Perception; D013028:Space Perception; D055698:Touch Perception; D014732:Vibration; D055815:Young Adult
keywords: Attention; Crossmodal interaction; Peripersonal space