Biology subjects

Duggirala, S. X.

Publications and source records attributed to Duggirala, S. X..

3 recordsLinked to original sources

bioRxiv2023

Exploring Neural Dynamics in Self-Voice Processing and Perception: Implications for Hallucination Proneness.

Altered sensory feedback processing and attention control are assumed to contribute to auditory verbal hallucinations, which are experienced by the general population and patients with psychosis, implying a continuum of hallucination proneness (HP). However, the interaction of altered sensory feedback processing and attention control along this HP continuum remains unclear. Manipulating the level of certainty of sensory feedback by changing self-voice quality (100% neutral, 60-40% neutral-angry, 50-50% neutral-angry, 40-60% neutral-angry, 100% angry) in individuals varying in HP, we tested this interaction using electroencephalography while participants self-generated or passively listened to their voices. Regardless of voice quality, HP modulated the N100 and P200 suppression effects. High HP individuals showed an increased N100 response to the self-generated voices and an increased P200 response for externally-generated voices. This may indicate increased error awareness and attention allocation in high HP individuals for self-voice generation stemming from altered sensory feedback processing, and/or attentional control. The current findings suggest that alterations of the sensory feedback processing in self-voice production are a fundamental characteristic of the continuum of HP, regardless of the clinical status of voice hearers. HighlightsO_LIAltered N100 voice suppression in high HP, regardless of the clinical status. C_LIO_LIHigh HP associated with altered sensory feedback processing and attentional control. C_LIO_LICurrent findings support a neurophysiological continuum of HP. C_LI

neuroscience↗

bioRxiv2023

Hallucination proneness alters sensory feedback processing in self-voice production

BackgroundSensory suppression occurs when hearing ones self-generated voice, as opposed to passively listening to ones own voice. Quality changes of sensory feedback to the self-generated voice can increase attentional control. These changes affect the self-other voice distinction and might lead to hearing non-existent voices in the absence of an external source (i.e., auditory verbal hallucinations (AVH)). However, it is unclear how changes in sensory feedback processing and attention allocation interact and how this interaction might relate to hallucination proneness (HP). Study DesignParticipants varying in HP self-generated and passively listened to their voice that varied in emotional quality and certainty of recognition -- 100% neutral, 60-40% neutral-angry, 50-50% neutral-angry, 40-60% neutral-angry, 100% angry, during EEG recordings. Study ResultsThe N1 auditory evoked potential was more suppressed for the self-generated than externally generated voices. Increased HP was associated with (i) an increased N1 response to the self-compared to externally generated voices, (ii) a reduced N1 response for angry compared to neutral voices, and (iii) a reduced N2 response to unexpected voice quality in sensory feedback (60-40% neutral-angry) compared to neutral voices. ConclusionsThe current study highlights an association between increased HP and systematic changes of the emotional quality and certainty in sensory feedback processing (N1) and attentional control (N2) in self-voice production in a non-clinical population. Considering that voice hearers also display these changes, these findings support the continuum hypothesis. However, additional research is needed to validate this conclusion.

neuroscience↗

bioRxiv2023

EEG resting state alpha dynamics predict individual proneness to auditory hallucinations

IntroductionAuditory verbal hallucinations (AVH) are a transdiagnostic phenomenon but also occur in the general population. The disposition to experience AVH is considered a continuous expression from non-clinical to clinical hallucination proneness (HP). Currently, little is known about the neurophysiology of the non-clinical HP part of the continuum. AVH might result from a heightened sensitivity to sensory inputs and a decreased ability to differentiate between externally and internally generated input. Resting state (RS) alpha band activity is associated with perceptual sensitivity, attentional shifts, and cognitive control. Accordingly, spontaneous alpha fluctuations might present as a HP correlate. To investigate the time-varying dynamics of alpha band activity, we deployed a novel method for brain state allocation. MethodsWe recorded RS electroencephalography (EEG) data from 33 individuals with varying levels of HP but without clinically relevant hallucinations and used a Hidden Semi-Markov Model (HsMM) to identify five recurrent alpha states with unique temporal dynamics and topographies. The states mean duration and occupancy were analyzed as a function of HP. The sources of each state were reconstructed to identify the most active brain areas and their correspondence with known resting state networks. ResultsOccupancy and mean duration of a state corresponding to sensorimotor, auditory, and default-mode network (DMN) areas significantly predicted auditory and auditory-verbal HP, but not general HP. The temporal dynamics of all other states did not relate to HP. ConclusionAlpha brain state sources align with prior results on the role of the alpha in the DMN. The temporal dynamics of alpha might reflect individual differences for attentional biases to internally generated sensory events and altered auditory perceptual sensitivity. Thus, changes in the temporal brain state dynamics of RS alpha oscillations could present as a neural marker of increased vulnerability to auditory hallucinatory experiences.

neuroscience↗