Previous work (Verrillo, 1963, 1968) has shown that when measured as a change in absolute threshold, spatial summation occurs only at vibration frequencies above 40 Hz. The present study measured vibrotactile spatial summation at suprathreshold amplitudes. A matchingtask was used to investig-ate the effect of varying contactor size on sensory magnitude at three different vibration frequencies. ...

Tactile sensory feedback plays an important role in our daily life. Transcutaneous electrical nerve stimulation (TENS) is widely accepted to produce artificial tactile sensation. To explore the underlying mechanism of tactile sensation under TENS, this paper presented a novel 3D TENS computational model including an active Aβ tactile nerve fiber (TNF) model and a forearm finite element model wi...

An important contributing factor for the high sensitivity of sensory systems is the exquisite sensitivity of the sensory receptor cells. We report here the signaling threshold of the olfactory receptor neuron (ORN). We first obtained a best estimate of the size of the physiological electrical response successfully triggered by a single odorant-binding event on a frog ORN, which was ∼0.034 pA an...

The nature and the origin of the small pre-potential wave which can be recorded immediately before the main muscle action potential on indirect stimulation was studied in the median nerve of 12 normal subjects. It is considered to be a sensory antidromic response recorded from the large afferent fibres which innervate the thumb because it was recorded in all 12 subjects, and the threshold was a...

Modern psychophysics has traveled considerably beyond the threshold measures that dominated sensory studies in the first half of this century. Current methods capture the range of perceived intensity from threshold to maximum and promise to provide increasingly accurate comparisons of perceived intensities across individuals. The application of new psychophysical tools to genetic variation in t...

OBJECTIVE To analyze the relationship between perceptions and electrical senoidal current stimulation (ESCS). METHOD The study population comprise 100 healthy volunteers. ESCS of 5 Hz and 2 kHz were applied to the left index finger at one and 1.5 sensory threshold. Following each stimulus train a list of eight words (four related to thin fiber sensations and four related to thick fiber sensat...

To what extent are sensory responses in the brain compatible with first-order principles? The efficient coding hypothesis projects that neurons use as few spikes as possible to faithfully represent natural stimuli. However, many sparsely firing neurons in higher brain areas seem to violate this hypothesis in that they respond more to familiar stimuli than to nonfamiliar stimuli. We reconcile th...

Synapses in the brain are continuously modified by experience, but the mechanisms are poorly understood. In vitro and theoretical studies suggest threshold-lowering interactions between nearby synapses that favor clustering of synaptic plasticity within a dendritic branch. Here, a fluorescently tagged AMPA receptor-based optical approach was developed permitting detection of single-synapse plas...

Many GABAergic interneurons are electrically coupled and in vitro can display correlated activity with millisecond precision. However, the mechanisms underlying correlated activity between interneurons in vivo are unknown. Using dual patch-clamp recordings in vivo, we reveal that in the presence of spontaneous background synaptic activity, electrically coupled cerebellar Golgi cells exhibit rob...

Background & Aims: The current study aimed to investigate the role of catastrophizing as mediator variable in the relationship of neuroticism and extraversion with fear of movement and pain intensity in patients with musculoskeletal pain. Methods: This study was conducted on 200 subjects who were selected through purposive sampling from among the clients of Sh...