The gap prepulse inhibition of the acoustic startle (GPIAS) paradigm to assess auditory temporal processing: Monaural versus binaural presentation

• Published in: Psychophysiology Vol. 58; no. 3; pp. e13755 - n/a
• Main Authors: Fournier, Philippe, Hébert, Sylvie
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.03.2021
• Subjects: acoustic startle reflex; Animal behavior; Animal models; binaural; EMG; gap‐Prepulse inhibition of the Acoustic startle reflex (GPIAS); Information processing; monaural; Noise; prepulse inhibition; Startle response; temporal processing; Tinnitus; temporal processing; gap-Prepulse inhibition of the Acoustic startle reflex (GPIAS); tinnitus; binaural; acoustic startle reflex; monaural; prepulse inhibition; EMG
• ISSN: 0048-5772; 1469-8986; 1540-5958
• DOI: 10.1111/psyp.13755

The Gap Prepulse Inhibition of the Acoustic Startle Reflex (GPIAS) is a paradigm used to assess auditory temporal processing in both animals and humans. It consists of the presentation of a silent gap embedded in noise and presented a few milliseconds before a startle sound. The silent gap produces the inhibition of the startle reflex, a phenomenon called gap‐prepulse inhibition (GPI). This paradigm is also used to detect tinnitus in animal models. The lack of inhibition by the silent gaps is suggested to be indicative of the presence of tinnitus “filling‐in” the gaps. The current research aims at improving the GPIAS technique by comparing the GPI produced by monaural versus binaural silent gaps in 29 normal‐hearing subjects. Two gap durations (5 or 50 ms), each embedded in two different frequency backgrounds (centered around 500 or 4 kHz). Both low‐ and high‐ frequency narrowband noises had a bandwidth of half an octave. Overall, the startle magnitude was greater for the binaural versus the monaural presentation, which might reflect binaural loudness summation. In addition, the GPI was similar between the monaural and the binaural presentations for the high‐frequency background noise. However, the GPI was greater for the low‐frequency background noise for the binaural, compared to the monaural, presentation. These findings suggest that monaural GPIAS might be more suited to detect tinnitus compared to the binaural presentation. Our research unveils the unexpected importance of background noise frequency between the monaural and binaural presentation of stimuli to elicit the Gap‐prepulse inhibition of the Acoustic Startle Reflex (GPIAS). Our findings suggest that monaural presentation of stimuli might be better suited to detect the presence of tinnitus, both in animals and in humans.