Auditory processing around actions: Evidence from psychophysics, electroencephalography, and pupillometry
[eng] The ability to distinguish self-generated stimuli from those caused by external sources is critical for all biological organisms. Although substantial work has been done in this domain, mainly showing attenuated perception and sensory processing for self-generated information, several issues r...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2022 |
| País: | España |
| Institución: | Universidad de Barcelona |
| Repositorio: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/203180 |
| Acceso en línea: | https://hdl.handle.net/2445/203180 http://hdl.handle.net/10803/689219 |
| Access Level: | acceso abierto |
| Palabra clave: | Neurociències Neurofisiologia Psicofisiologia Cervell Neurosciences Neurophysiology Psychophysiology Brain |
| Sumario: | [eng] The ability to distinguish self-generated stimuli from those caused by external sources is critical for all biological organisms. Although substantial work has been done in this domain, mainly showing attenuated perception and sensory processing for self-generated information, several issues remain unknown, mainly related to the direction of the action effects on behavioural and sensory responses, the nature of the effects, but also the influence of other factors that are often confounded with self-generation. The present thesis attempts to elucidate the mechanisms underlying the effects of actions on auditory processing. In three original studies, we examined the self-generation effects from the angles of behavioural responses, namely perceptual processing and memory encoding, and basic physiology, namely electrophysiological responses and neuromodulatory processes (i.e., measured with pupillometry). Study I tested for possible interactions between actions and stimulus intensity on sound detection and loudness discrimination, while examining which aspect of perception is modulated (sensitivity or bias). Study II addressed the effects of cued actions on sensory processing and memory encoding of concurrent, but unpredictable, sounds, while exploring for the first time the involvement of neuromodulatory systems in the action-induced modulations of auditory responses. Study III disentangled self-generation and predictability – two factors that have been conflated in previous work – and assessed how they interact in shaping auditory responses, subcortical neuromodulation, and memory encoding of sounds. Finally, Study II and Study III also tested for possible links between memory encoding, sensory attenuation, and subcortical neuromodulation. Related to the behavioural findings, the present thesis tapped onto two main research lines, namely low-level perceptual processing and memory encoding. Study I showed that actions interact with stimulus intensity on perceptual bias, but not sensitivity measures. Study II and Study III showed that actions modulate memory performance, but the direction of the effects depends on predictability confounds and the type of action. Specifically, when actions are cued and afford temporal predictability, memory performance drops and relates to the magnitude of the attenuation effects for self-generated sounds (Study II). In contrast, in the absence of predictability confounds and when action alternatives are provided, the mere presence of an action enhances memory performance of sounds, but this enhancement does not relate to the suppression effects (Study III). Related to the effects of actions on sensory processing, the present thesis assessed the specificity of the action-induced attenuation effects and clarified the role of neuromodulatory processes in sensory suppression. Study II showed that cued actions attenuated sensory responses and increased pupil diameter despite the absence of a predictive action-sound relationship, but sensory suppression and subcortical neuromodulation were not related. Study III employed a predictable and an unpredictable session where both self- and externally- generated sounds were equally predictable in identity, timing, and probability of occurrence and were presented shortly after or farther away from the action or cue, respectively. With short delays, predictability mattered since attenuation was only obtained in the predictable session. With longer delays, self-generation and predictability no longer interacted: N1- attenuation was driven by self-generation only, while Tb- and P2-attenuation were driven by predictability only. Crucially, pupil diameter increased during actions, interacted with predictability, and was linked to the Tb-attenuation when the effects were strongest (i.e., with fully contingent action-sound relationship and short action-sound delays). Taken together, the present thesis disentangled the contribution of factors other than self- generation in modulating perception, memory, and neurophysiological responses for self- generated inputs (i.e., sound intensity, predictability, and action-sound delay), and showed that actions trigger a cascade of stimulus-specific and unspecific processes – presumably driven by subcortical neuromodulatory processes – that collaboratively orchestrate auditory processing and memory encoding. |
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