The responses of neocortical cells to sensory stimuli are variable and state dependent. It has been hypothesized that intrinsic cortical dynamics play an important role in trial-to-trial variability; the precise nature of this dependence, however, is poorly understood. We show here that in auditory cortex of urethane-anesthetized rats, population responses to click stimuli can be quantitatively...

We used optical imaging of intrinsic signals to study the large-scale organization of ferret auditory cortex in response to complex sounds. Cortical responses were collected during continuous stimulation by sequences of sounds with varying frequency, period, or interaural level differences. We used a set of stimuli that differ in spectral structure, but have the same periodicity and therefore e...

A differentiation of instrumental responses to auditory location stimuli using the Konorski Test was investigated. Each stimulus consisted of two components separated by intrastimulus interval. The components were click series presented from four loudspeakers situated in front of the animal, on horizontal and vertical axes. Each correct response, performed to the second component of positive st...

We studied the effects on the auditory brainstem response (ABR) of applying a computerized calibration procedure for click stimuli that corrects for individual transducer characteristics and ear canal acoustics. The "calibrated" signal at the eardrum possesses a nearly flat spectrum from 500 to 10,000 Hz. ABRs were recorded from normal-hearing subjects using both calibrated and uncalibrated cli...

We measured the interaural attenuation for click stimuli using insert earphones. Electrocochleographic thresholds were determined when clicks were presented both ipsilaterally and contralaterally to the recording ear. The interaural attenuation was calculated as the difference between ipsilateral and contralateral thresholds. Results from normal listeners showed that crossover occurred. Results...

In the previous paper (1-4), we have been able to demonstrate systematically the relationship between the cortical auditory responses evoked by clicks and the level of consciousness in the acute encephale isole preparations of cat. Furthermore, the effects of several central depressants on the evoked responses in the central auditory system caused by single and repetitive click stimuli have bee...