Examining replicability of an otoacoustic measure of cochlear function during selective attention

Abstract

Attention to a target stimulus within a complex scene often results in enhanced cortical representations of the target relative to the background. It remains unclear where along the auditory pathways attentional effects can first be measured. Anatomy suggests that attentional modulation could occur through corticofugal connections extending as far as the cochlea itself. Earlier attempts to investigate the effects of attention on human cochlear processing have revealed small and inconsistent effects. In this study, stimulus-frequency otoacoustic emissions were recorded from a total of 30 human participants as they performed tasks that required sustained selective attention to auditory or visual stimuli. In the first sample of 15 participants, emission magnitudes were significantly weaker when participants attended to the visual stimuli than when they attended to the auditory stimuli, by an average of 5.4 dB. However, no such effect was found in the second sample of 15 participants. When the data were pooled across samples, the average attentional effect was significant, but small (2.48 dB), with 12 of 30 listeners showing a significant effect, based on bootstrap analysis of the individual data. The results highlight the need for considering sources of individual differences and using large sample sizes in future investigations. V

Effect of Auditory Predictability on the Human Peripheral Auditory System

“…Our study shows that intramodal top-down attention may modulate the processing of predictable spectral input in the peripheral auditory system, thereby adding support to current debate on the sensitivity of the human auditory peripheral system to top-down modulation (e.g., Beim et al, 2018;Lopez-Poveda, 2018). Our observations further indicate that predictability may affect auditory processing in the peripheral auditory system.…”

“…The auditory targets in our auditory task (which were defined by the pitch of the two primaries) differed from the investigated DPOAE frequencies, similar to some previous OAE attention studies (Srinivasan et al, 2012(Srinivasan et al, , 2014Wittekindt et al, 2014). It is unlikely that this difference largely reduced effect sizes in our study because acoustically evoked (Norman and Thornton, 1993;Lisowska et al, 2002) (review: Guinan, 2018 and attentionmodulated (Srinivasan et al, 2012(Srinivasan et al, , 2014Wittekindt et al, 2014;Beim et al, 2018) MOC reflexes show only little frequency tuning in humans.…”

“…Figure 4A shows the grand average sound-pressure level spectrum of participants' OAE recordings (pooled across tone frequencies and positions, and aligned to DP frequency). The DPOAE level and noise floor were on average −15.4 ± 6.0 dB SPL and −28.7 ± 5.4 dB SPL, which corresponds to an average DPOAE SNR of 13.4 ± 4.8 dB (mean ± SD across participants), a lower value than individual OAE SNR values (>20 dB) reported in previous attention studies using acoustic MOC-reflex elicitors (e.g., Beim et al, 2018). Figure 4B shows the DPOAE level for each condition.…”

“…Efferent MOC-fiber activity can be modulated in a 'topdown' manner: electric microstimulation or deactivation of the auditory cortex alters OHC activity as measured with cochlear microphonics or otoacoustic emissions (OAEs) (Perrot et al, 2006;Dragicevic et al, 2015;Terreros and Delano, 2015;Jager and Kossl, 2016). Similarly, changes in arousal or endogenous (interor intramodal) attention may lead to OHC-activity changes as measured with OAEs (Puel et al, 1988;Froehlich et al, 1990Froehlich et al, , 1993Giard et al, 1994;Ferber-Viart et al, 1995;Maison et al, 2001;de Boer and Thornton, 2007;Harkrider and Bowers, 2009;Smith et al, 2012;Srinivasan et al, 2012Srinivasan et al, , 2014Walsh et al, 2014Walsh et al, , 2015Wittekindt et al, 2014;Smith and Cone, 2015), although the existence and direction of these top-down attention effects are still debated (Picton et al, 1971;Avan and Bonfils, 1992;Michie et al, 1996;Beim et al, 2018Beim et al, , 2019Francis et al, 2018;Lopez-Poveda, 2018).…”

Cochlear activity in silent cue-target intervals shows a theta-rhythmic pattern and is correlated to attentional alpha modulations

“…These effects have been mainly established on a cortical level (Frey et al, 2015;Shrem & Deouell, 2017); however, it is less clear to what extent selective attention modulates subcortical activity (Guinan, 2018). For the auditory system, this dispute extends down to the level of the cochlea (Beim et al, 2018;Giard et al, 1994;Lopez-Poveda, 2018).…”