We investigated connections between the physiology of rat barrel cortex neurons and the sensation of vibration in humans. One set of experiments measured neuronal responses in anesthetized rats to trains of whisker deﬂections, each train characterized either by constant amplitude across all deﬂections or by variable amplitude (“amplitude noise”). Firing rate and ﬁring synchronywere, on aver- age, boosted by the presence of noise. However, neurons were not uniform in their responses to noise. Barrel cortex neurons have been categorized as regular-spiking units (putative excitatory neurons) and fast-spiking units (putative inhibitory neurons). Among regular-spiking units, amplitude noise caused a higher ﬁring rate and increased cross-neuron synchrony. Among fast-spiking units, noise had the opposite effect: It led to a lower ﬁring rate and decreased cross-neuron synchrony. This ﬁnding suggests that amplitude noise affects the interaction between inhibitory and excitatory neurons. From these physiological effects, we expected that noise would lead to an increase in the perceived intensity of a vibration. We tested this notion using psychophysical measurements in humans. As predicted, subjects overestimated the intensity of noisy vibrations. Thus the physiological mechanisms present in barrel cortex also appear to be at work in the human tactile system, where they affect vibration perception.
|Titolo:||Correlated physiological and perceptual effects of noise in a tactile stimulus|
|Autori:||Lak A; Arabzadeh E; Diamond M|
|Data di pubblicazione:||2010|
|Appare nelle tipologie:||1.1 Journal article|