Diminished auditory sensory gating during active auditory verbal hallucinations

Abstract

Auditory sensory gating, assessed in a paired-click paradigm, indicates the extent to which incoming stimuli are filtered, or “gated”, in auditory cortex. Gating is typically computed as the ratio of the peak amplitude of the event related potential (ERP) to a second click (S2) divided by the peak amplitude of the ERP to a first click (S1). Higher gating ratios are purportedly indicative of incomplete suppression of S2 and considered to represent sensory processing dysfunction. In schizophrenia, hallucination severity is positively correlated with gating ratios, and it was hypothesized that a failure of sensory control processes early in auditory sensation (gating) may represent a larger system failure within the auditory data stream; resulting in auditory verbal hallucinations (AVH). EEG data were collected while patients (N = 12) with treatment-resistant AVH pressed a button to indicate the beginning (AVH-on) and end (AVH-off) of each AVH during a paired click protocol. For each participant, separate gating ratios were computed for the P50, N100, and P200 components for each of the AVH-off and AVH-on states. AVH trait severity was assessed using the Psychotic Symptoms Rating Scales AVH Total score (PSYRATS). The results of a mixed model ANOVA revealed an overall effect for AVH state, such that gating ratios were significantly higher during the AVH-on state than during AVH-off for all three components. PSYRATS score was significantly and negatively correlated with N100 gating ratio only in the AVH-off state. These findings link onset of AVH with a failure of an empirically-defined auditory inhibition system, auditory sensory gating, and pave the way for a sensory gating model of AVH.

Aberrant oscillatory dynamics during somatosensory processing in HIV-infected adults

“…As briefly described in the introduction, sensory gating is a process whereby the response to the second stimulus in a pair of redundant stimuli is attenuated. While this process has been extensively studied in the auditory domain with respect to schizophrenia and other psychiatric disorders ( Cheng et al, 2016a ; Light and Braff, 1999 ; Thoma et al, 2017 ), far fewer studies have examined such gating in the somatosensory cortices. Furthermore, this phenomenon had yet to be investigated with respect to the impact of HIV on the CNS.…”

“…This attenuation is thought to reflect the capacity of the CNS to filter less relevant information and preserve resources for behaviorally-relevant stimuli ( Cromwell et al, 2008 ). Substantial evidence suggests that patients with cerebral palsy, schizophrenia, bipolar disorder and even healthy older adults exhibit impaired gating of auditory and/or somatosensory stimuli, which is thought to reflect an impairment in bottom-up, pre-attentive inhibitory processing ( Cheng et al, 2016a ; Kurz et al, 2018 ; Light and Braff, 1999 ; Spooner et al, 2018 ; Thoma et al, 2017 ). Interestingly, no study to date has evaluated gating in the somatosensory system of HIV-infected patients, which is surprising given that attentive or top-down inhibitory processing is thought to be a critical deficit ( Hoare et al, 2016 ; Martin et al, 1992a ; Martin et al, 1992b ; Walker and Brown, 2017 ) and there is existent data suggesting that attentive and pre-attentive inhibitory processes are closely linked in healthy adults.…”

Is schizotypic maternal personality linked to sensory gating abilities during infancy?

“…Here, significant effects were observed in the suppression ratio scores in the infant population, and in both difference and suppression ratio measures in the maternal cohort. An additional strength, multiple electrode sites were utilised for analysis when contrasted with prior research, which explored sensory gating in the central regions, specifically CZ, and utilised a mastoid or earlobe reference (Toyomaki et al 2015 ; Hunter et al 2015 ; Thoma et al 2017 ). An advantage of the current research is the quantity of electrodes in the high-density array.…”

Sensory Gating Deficits and their Clinical Correlates in Drug-Free/Drug-Naive Patients with Schizophrenia

“…Not controlling for this factor might confound the generalizability of the findings as it has been found that sensory gating significantly differs between auditory hallucinations “on” and “off” states. [ 60 ]…”