Dissociation of task engagement and arousal effects in auditory cortex and midbrain

Abstract

Both generalized arousal and engagement in a specific task influence sensory neural processing. To isolate effects of these state variables in the auditory system, we recorded single-unit activity from primary auditory cortex (A1) and inferior colliculus (IC) of ferrets during a tone detection task, while monitoring arousal via changes in pupil size. We used a generalized linear model to assess the influence of task engagement and pupil size on sound-evoked activity. In both areas, these two variables affected independent neural populations. Pupil size effects were more prominent in IC, while pupil and task engagement effects were equally likely in A1. Task engagement was correlated with larger pupil; thus, some apparent effects of task engagement should in fact be attributed to fluctuations in pupil size. These results indicate a hierarchy of auditory processing, where generalized arousal enhances activity in midbrain, and effects specific to task engagement become more prominent in cortex.

Brainstem speech encoding is dynamically shaped online by fluctuations in corticalαstate

“…Central auditory processing of target sounds is influenced by multiple factors, such as background noise ( Binkhamis et al, 2019; Billings et al, 2020; Song et al, 2011 ), task engagement ( Saderi et al, 2021; Shaheen et al, 2021 ), attention ( Saiz-Alía et al, 2019; Price and Bidelman, 2021 ), and arousal state ( Mai et al, 2019; Saderi et al, 2021 ). These factors may interact to modulate sound processing differentially.…”

“…Central auditory processing of target sounds is influenced by multiple factors, such as background noise (Binkhamis, Léger, Bell, Prendergast, O’Driscoll and Kluk, 2019; Billings, Gordon, McMillan, Gallun, Molis and Konrad-Martin, 2020; Song, Skoe, Banai and Kraus, 2011), task engagement (Saderi, Schwartz, Heller, Pennington and David, 2021; Shaheen, Slee and David, 2021), attention (Saiz-Alía, Forte and Reichenbach, 2019; Price and Bidelman, 2021), and arousal state (Mai, Schoof and Howell, 2019; Saderi et al, 2021). These factors may interact to modulate sound processing differentially.…”

Strategic stabilization of arousal boosts sustained attention

“…Global arousal, controlled by neuromodulatory systems that make up the reticular activating system (Aston-Jones & Cohen, 2005;McGinley, Vinck, et al, 2015), is thought to be a key physiological mediator of the effects of motivation on attentional intensity. Some evidence, consistent with traditional metabolic and capacity theories, argues that increased arousal is associated with increased attentional performance (Hasselmo & McGaughy, 2004;Massar et al, 2016;Parikh et al, 2007;Saderi et al, 2021). Other evidence suggests just the opposite, that high arousal is associated with task disengagement, and thus that improved attention occurs with lower arousal (Aston-Jones & Cohen, 2005;Gilzenrat et al, 2010;Jepma & Nieuwenhuis, 2011;Usher et al, 1999).…”

Post-error Slowing Reflects the Joint Impact of Adaptive and Maladaptive Processes During Decision Making

“…Hence, it is plausible that in the current study, post-error task engagement was larger following misleading than ambiguous trial n-1 , allowing PES to result in a performance gain following the former but not the latter trial type. Such a hypothesis could be tested in future work by investigating changes in pupil diameter following errors in our task (Kahneman and Beatty, 1966 ; Saderi et al, 2021 ).…”