The hearing thresholds of the horn shark Heterodontus francisci and the white-spotted bamboo shark Chiloscyllium plagiosum were measured using auditory evoked potentials (AEP) in response to a dipole sound stimulus. The audiograms were similar between the two species with lower frequencies yielding lower particle acceleration thresholds. The particle acceleration audiograms showed more sensitiv...

OBJECTIVE The aim of this study was to determine whether, in young children, a cortical neurophysiologic representation of the voicing status of a stop consonant could be found in the absence of the N1 component in the cortical auditory evoked potential (CAEP). In adults, a 'double-on' N1 response is often considered a cortical marker of VOT representation. METHODS Scalp-recorded CAEPs were m...

Given previous reports of strong interactions between vision and somatic senses, we investigated whether vision of the body modulates pain perception. Participants looked into a mirror aligned with their body midline at either the reflection of their own left hand (creating the illusion that they were looking directly at their own right hand) or the reflection of a neutral object. We induced pa...

Perception and discrimination of auditory and speech stimuli in children aged 7-9 years with either receptive (n=6) or expressive (n=5) type of special language impairment and 7 healthy age-matched controls was investigated using evoked potential technique. The measurements were performed with a 32-channel Neuroscan electroencephalographic system. Two types of stimuli were applied, pure tones (...

BACKGROUND Many anaesthetists are deterred from using total i.v. anaesthesia because of uncertainty over the concentration of propofol required to prevent awareness. We predicted blood and effect-site concentrations of propofol at two clinical end-points: loss of consciousness and no response to a painful stimulus. METHODS Forty unpremedicated Caucasian patients were anaesthetized with i.v. p...

The shape of evoked potentials is influenced by the level of vigilance, varying with sleep-wake states. In this paper the shape of auditory evoked potentials is modelled by taking two factors, both modulating the underlying neuronal substrate, into account: 'sensory gating' and 'neuronal firing mode'. Under low levels of vigilance sensory gating reduces the amount of neuronal activity reaching ...

The objectives of this study were to characterize the auditory cortex response in the rat and to examine its contributions to the auditory evoked potentials (AEPs) recorded from the dorsal and lateral skull. This was accomplished by simultaneously recording AEPs from the cortical surface and from skull screw electrodes in anesthetized animals. The initial positive-negative response (P17-N32) wa...

Researchers recently reported evidence of a possible electrophysiologic correlate of impaired binaural processing or attention in elderly subjects. This experiment found that the presence of speech competition in the contralateral nontest ear produced significantly greater decreases in the peak-to-peak amplitude of the N1-P2 component of the late auditory evoked potential (LAEP) in an older gro...

This study addressed the issue of multiple parallel auditory processing systems and their relationship to the skull-recorded auditory evoked potentials (AEPs) in the unanesthetized, unrestrained rat. In the preceding paper (Brain Res., 602 (1993) 240-250) it has been shown that auditory cortex activity does not contribute significantly to the vertex maximal AEPs recorded from the dorsal skull o...