Vinay Tannan

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Although sensory problems, including unusual tactile sensitivity, are heavily associated with autism, there is a dearth of rigorous psychophysical research. We compared tactile sensation in adults with autism to controls on the palm and forearm, the latter innervated by low-threshold unmyelinated afferents subserving a social/affiliative submodality of(More)
The capacity of 20 healthy adult subjects for detecting differences in the amplitude of two simultaneously delivered 25 Hz vibrotactile stimuli was assessed both in the absence and presence of prior exposure to different conditions of adapting stimulation. Results obtained from this study demonstrate that increasing durations of adapting stimulation at one(More)
Current methods for applying multi-site vibratory stimuli to the skin typically involve the use of two separate vibrotactile stimulators, which can lead to difficulty with positioning of stimuli and in ensuring that stimuli are delivered perfectly in phase at the same amplitude and frequency. Previously, we reported a two-point stimulator (TPS) that was(More)
It is established that increasing the amplitude of a flutter stimulus increases its perceived intensity. Although many studies have examined this phenomenon with regard to the responding afferent population, the way in which the intensity of a stimulus is coded in primary somatosensory cortex (SI) remains unclear. Optical intrinsic signal (OIS) imaging was(More)
In this study, we investigated the changes in perceptual metrics of amplitude discrimination that were observed in ten healthy human subjects with increasing intensities of stimulation. The ability to perceive differences in vibrotactile amplitude changed systematically with increasing stimulus magnitude (i.e., followed Weber’s Law) in a near linear fashion(More)
A recent study [Tannan, V., Tommerdahl, M., Whitsel, B.L., 2006. Vibrotactile adaptation enhances spatial localization. Brain Res. 1102(1), 109-116 (Aug 2)] showed that pre-exposure of a skin region to a 5 s 25 Hz flutter stimulus ("adaptation") results in an approximately 2-fold improvement in the ability of neurologically healthy human adults to localize(More)
Adults with autism exhibit inhibitory deficits that are often manifested in behavioral modifications, such as repetitive behaviors, and/or sensory hyper-responsiveness. If such behaviors are the result of a generalized deficiency in inhibitory neurotransmission, then it stands to reason that deficits involving localized cortical-cortical interactions--such(More)
A two-interval forced choice tracking procedure was used to evaluate the effects of a pre-exposure to vibrotactile stimulation ("adaptation") on the capacity of human subjects to spatially localize a subsequent tactile stimulus. A 25 Hz flutter adapting stimulus was presented at a randomly selected position within a 20 mm linear array oriented transversely(More)
Previous reports have demonstrated that short durations of vibrotactile stimuli (less than or equal to 2 sec) effectively and consistently modify both the perceptual response in humans as well as the neurophysiological response in somatosensory cortex. The change in cortical response with adaptation has been well established by a number of studies, and(More)
Previous studies have shown that spatio-tactile acuity is influenced by the clarity of the cortical response in primary somatosensory cortex (SI). Stimulus characteristics such as frequency, amplitude, and location of tactile stimuli presented to the skin have been shown to have a significant effect on the response in SI. The present study observes the(More)