Modulation of the Primary Auditory Thalamus When Recognizing Speech with Background Noise
- 9 July 2021
- journal article
- research article
- Published by Society for Neuroscience in Journal of Neuroscience
- Vol. 41 (33), 7136-7147
- https://doi.org/10.1523/jneurosci.2902-20.2021
Abstract
Recognising speech in background noise is a strenuous daily activity, yet most humans can master it. An explanation of how the human brain deals with such sensory uncertainty during speech recognition is to-date missing. Previous work has shown that recognition of speech without background noise involves modulation of the auditory thalamus (medial geniculate body, MGB): There are higher responses in left MGB for speech recognition tasks that require tracking of fast-varying stimulus properties in contrast to relatively constant stimulus properties (e.g., speaker identity tasks) despite the same stimulus input. Here we tested the hypotheses that (i) this task-dependent modulation for speech recognition increases in parallel with the sensory uncertainty in the speech signal, i.e., the amount of background noise and that (ii) this increase is present in the ventral MGB, which corresponds to the primary sensory part of the auditory thalamus. In accordance with our hypothesis, we show—by using ultra-high-resolution functional magnetic resonance imaging in male and female human participants—that the task-dependent modulation of the left vMGB for speech is particularly strong when recognizing speech in noisy listening conditions in contrast to situations where the speech signal is clear. The results imply that speech in noise recognition is supported by modifications at the level of the subcortical sensory pathway providing driving input to the auditory cortex. SIGNIFICANCE STATEMENT: Speech recognition in noisy environments is a challenging everyday task. One reason why humans can master this task is the recruitment of additional cognitive resources as reflected in recruitment of non-language cerebral cortex areas. Here, we show that also modulation in the primary sensory pathway is specifically involved in speech in noise recognition. We found that the left primary sensory thalamus (ventral medial geniculate body, vMGB) is more involved when recognizing speech signals as opposed to a control task (speaker identity recognition) when heard in background noise vs. when the noise was absent. This finding implies that the brain optimises sensory processing in subcortical sensory pathway structures in a task-specific manner to deal with speech recognition in noisy environments.This publication has 98 references indexed in Scilit:
- Predictions not commands: active inference in the motor systemBrain Structure and Function, 2012
- A review and synthesis of the first 20years of PET and fMRI studies of heard speech, spoken language and readingNeuroImage, 2012
- Dysfunction of the auditory thalamus in developmental dyslexiaProceedings of the National Academy of Sciences of the United States of America, 2012
- Context-Dependent Encoding in the Human Auditory Brainstem Relates to Hearing Speech in Noise: Implications for Developmental DyslexiaNeuron, 2009
- Predictive coding under the free-energy principlePhilosophical Transactions B, 2009
- Aging and cortical mechanisms of speech perception in noiseNeuropsychologia, 2009
- Task-Dependent Modulation of Medial Geniculate Body Is Behaviorally Relevant for Speech RecognitionCurrent Biology, 2008
- Neural coding of temporal information in auditory thalamus and cortexNeuroscience, 2008
- Symmetric diffeomorphic image registration with cross-correlation: Evaluating automated labeling of elderly and neurodegenerative brainMedical Image Analysis, 2008
- The Bayesian brain: the role of uncertainty in neural coding and computationTrends in Neurosciences, 2004