A Method for Simultaneous Evaluation of Muscular and Neural Prepulse Inhibition

Author(s)

San-Martin, Rodrigo ^[1] ; Zimiani, Maria Ines ^[1] ; Noya, Claudemiro ^[2] ; Vendramini Avila, Milton Augusto ^[3] ; Shuhama, Rosana ^[3] ; Del-Ben, Cristina Marta ^[3] ; Menezes, Paulo Rossi ^{[4, 5]} ; Fraga, Francisco Jose ^[2] ; Salum, Cristiane ^[1]

Affiliation

^[1] Univ Fed ABC, Ctr Math Computat & Cognit, Sao Bernardo Do Campo - Brazil

^[2] Univ Fed ABC, Engn Modeling & Appl Social Sci Ctr, Santo Andre - Brazil

^[3] Univ Sao Paulo, Ribeirao Preto Med Sch, Ribeirao Preto - Brazil

^[4] Univ Sao Paulo, Dept Prevent Med, Fac Med, Sao Paulo - Brazil

^[5] Univ Sao Paulo, Populat Mental Hlth Res Ctr, Sao Paulo - Brazil

• Document type: Journal article
• Source: FRONTIERS IN NEUROSCIENCE; v. 12, SEP 26 2018.
• Web of Science Citations: 0

Abstract

Prepulse inhibition (PPI) test has been widely used to evaluate sensorimotor gating. In humans, deficits in this mechanism are measured through the orbicularis muscle response using electromyography (EMG). Although this mechanism can be modulated by several brain structures and is impaired in some pathologies as schizophrenia and bipolar disorder, neural PPI evaluation is rarely performed in humans. Since eye blinks are a consequence of PPI stimulation, they strongly contaminate the electroencephalogram (EEG) signal. This paper describes a method to reduce muscular artifacts and enable neural PPI assessment through EEG in parallel to muscular PPI evaluation using EMG. Both types of signal were simultaneously recorded in 22 healthy subjects. PPI was evaluated by the acoustical startle response with EMG and by the P2-N1 event-related potential (ERP) using EEG in Fz, Cz, and Pz electrodes. In order to remove EEG artifacts, Independent Component Analysis (ICA) was performed using two methods. Firstly, visual inspection discarded components containing artifact characteristics as ocular and tonic muscle artifacts. The second method used visual inspection as gold standard to validate parameters in an automated component selection using the SASICA algorithm. As an outcome, EEG artifacts were effectively removed and equivalent neural PPI evaluation performance was obtained using both methods, with subjects exhibiting consistent neural as well as muscular PPI. This novel method improves PPI test, enabling neural gating mechanisms assessment within the latency of 100-200 ms, which is not evaluated by other sensory gating tests as P50 and mismatch negativity. (AU)

• FAPESP's process: 13/11167-3 - Gene-environment interactions in Schizophrenia and other psychotic disorders
• Grantee: Rosana Shuhama
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 12/05178-0 - Schizophrenia and other psychotic disorders: social and biological determinants
• Grantee: Paulo Rossi Menezes
• Support Opportunities: Research Projects - Thematic Grants