Characterization of Volume-Based Changes in Cortical Auditory Evoked Potentials and Prepulse Inhibition

Abstract

The auditory evoked startle reflex is a conserved response resulting in neurological and motor activity. The presence of a mild prepulse immediately before the main pulse inhibits startle responses, though the mechanism for this remains unknown. In this study, the electroencephalography (EEG) data recorded from 15 subjects was analyzed to study the N1 and P2 components of cortical auditory evoked potentials (CAEPs) evoked by 70, 80, 90, 100, and 110 dB stimuli both in the presence and absence of 70 dB prepulses. Results without a prepulse showed an evolution of N1 amplitudes, increasing with stimulus intensity and showing largely significant differences. Results from prepulse trials only showed noteworthy changes in peak-to-peak amplitude in the 100 dB condition. Prepulse and non-prepulse conditions were then compared using peak amplitudes and theta power. Prepulse conditions significantly decreased the amplitude for both components in the 110 dB condition, i.e., pre-pulse inhibition, but significantly increased the N1 amplitude in the 70 dB condition, i.e., pre-pulse facilitation. Similarly theta band power significantly increased in the 70 dB prepulse condition and significantly decreased in the 110 dB prepulse condition. These results expand the basis of knowledge regarding how CAEPs change and elaborate on their neural function and representation.

Neural signatures of memory gain through active exploration in an oculomotor‐auditory learning task

“…However, the correlational finding between the attenuation of the N1 component and the memory performance of individual subjects suggests that whatever differences in performance we find are at least partly due to perceptual differences during learning: The auditory N1 component is a well‐studied marker of early auditory processing. It is mainly generated in and around primary auditory cortex (Celesia, 1976; Giard et al, 1994); its amplitude is known to reflect stimulus intensity (louder stimuli trigger a stronger N1 amplitude), and it is known to be attenuated for self‐generated stimuli (Bäß et al, 2008; Potter et al, 2017). N1 suppression is frequently interpreted as reflecting an internal predictive mechanism serving the discrimination by the perceptual system of self‐ and externally generated sensory events (Baess et al, 2011; Horváth, 2015; Horváth et al, 2012; Schäfer & Marcus, 1973; Timm et al, 2013).…”

Phasic activation of the locus coeruleus attenuates the acoustic startle response by increasing cortical arousal

“…The AEPs are recorded in many subcortical and cortical structures. The N1 and P2 peaks, two early AEP components, are commonly considered to reflect the sound intensity 67 – 69 . The AEP amplitude, like other sensory responses, is attenuated during low arousal states 70 – 72 .…”

A Knowledge-Based Pilot Study on Assessing the Music Influence

“…1, the background music-preferred versus unwanted genre-was the same and was generated based on the generated playlists (a process described above). The music was broadcast via external speakers and the sound level varied between 30 and 35 decibels, the level being considered safe according to international regulations, specialized scientific studies [35], and from the perspective of national regulations imposed by the Ministry of Health.…”