title: Effects of passive and active movement on vibrotactile detection thresholds of the Pacinian channel and forward masking.
abstract: We investigated the gating effect of passive and active movement on the vibrotactile detection thresholds of the Pacinian (P) psychophysical channel and forward masking. Previous work on gating mostly used electrocutaneous stimulation and did not allow focusing on tactile submodalities. Ten healthy adults participated in our study. Passive movement was achieved by swinging a platform, on which the participant's stimulated hand was attached, manually by a trained operator. The root-mean-square value of the movement speed was kept in a narrow range (slow: 10-20 cm/s, fast: 50-60 cm/s). Active movement was performed by the participant him-/herself using the same apparatus. The tactile stimuli consisted of 250-Hz sinusoidal mechanical vibrations, which were generated by a shaker mounted on the movement platform and applied to the middle fingertip. In the forward-masking experiments, a high-level masking stimulus preceded the test stimulus. Each movement condition was tested separately in a two-interval forced-choice detection task. Both passive and active movement caused a robust gating effect, that is, elevation of thresholds, in the fast speed range. Statistically significant change of thresholds was not found in slow movement conditions. Passive movement yielded higher thresholds than those measured during active movement, but this could not be confirmed statistically. On the other hand, the effect of forward masking was approximately constant as the movement condition varied. These results imply that gating depends on both peripheral and central factors in the P channel. Active movement may have some facilitatory role and produce less gating. Additionally, the results support the hypothesis regarding a critical speed for gating, which may be relevant for daily situations involving vibrations transmitted through grasped objects and for manual exploration.
authors.affiliation: a Institute of Biomedical Engineering, Boğaziçi University, Kandilli Campus, Çengelköy , Istanbul , Turkey and.|b Faculty of Technology , Electrical and Electronics Engineering Department, Sakarya University, Esentepe Campus , Serdivan , Sakarya , Turkey.
authors.forename: Mustafa Z
authors.initials: MZ
authors.lastname: Yıldız
authors.affiliation: a Institute of Biomedical Engineering, Boğaziçi University, Kandilli Campus, Çengelköy , Istanbul , Turkey and.
authors.forename: İpek
authors.initials: İ
authors.lastname: Toker
authors.affiliation: a Institute of Biomedical Engineering, Boğaziçi University, Kandilli Campus, Çengelköy , Istanbul , Turkey and.
authors.forename: Fatma B
authors.initials: FB
authors.lastname: Özkan
authors.affiliation: a Institute of Biomedical Engineering, Boğaziçi University, Kandilli Campus, Çengelköy , Istanbul , Turkey and.
authors.forename: Burak
authors.initials: B
authors.lastname: Güçlü
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000704:Analysis of Variance; D002755:Choice Behavior; D005260:Female; D006801:Humans; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D010470:Perceptual Masking / Q000502:physiology*; D010812:Physical Stimulation; D011601:Psychophysics; D012684:Sensory Thresholds / Q000502:physiology*; D017603:Signal Detection, Psychological / Q000502:physiology*; D014110:Touch / Q000502:physiology
keywords: Active touch; gating; movement; psychophysics; somatosensory; touch