Postersession 1
Poster #: 61
Topic: Error signals
Wednesday, Sep 9, 2015
17:00-18:30
1st floor
Predicting complex acoustic contingencies in the human auditory brainstem
1Department of Psychiatry and Clinical Psychobiology, Cognitive Neuroscience Research Group, Barcelona, Spain
2Cognitive Neuroscience Research Group, Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Spain;niversity of Barcelona, Spain;, Institute for Brain, Cognition and Behavior (IR3C), University of Barcelona, Catalonia-Spain;, Barcelona, Spain
3Institute for Brain, Cognition and Behavior (IR3C) and Dep. of Psychiatry and Clinical Psychobiology, University of Barcelona, Barcelona, Spain
4Auditory Neurophysiology Laboratory, Institute of Neuroscience of Castilla y León (INCyL); Department of Cell Biology and Pathology, Faculty of Medicine, University of Salamanca, Salamanca, Spain
5Institute for Brain, Cognition and Behavior (IR3C), University of Barcelona, Barcelona, Spain
johanna.schaefer@ub.edu
Higher level sensory processing is thought to be subject of cortical sensory areas. On the cortical level, our auditory system is capable of extracting abstract regularities within the acoustic environment. Here, we investigated whether the subcortical auditory system, specifically the brainstem is capable of representing complex acoustic feature contingencies. We presented sequences of sinusoidal tones of different frequencies (low: 256 Hz, high: 441 Hz) and durations (short: 100 ms, long: 185 ms). Within the rule sequence the duration of the preceding tone predicted the frequency of the upcoming tone, e.g. a short tone was followed by a low tone and a long tone was followed by a high tone (Bendixen et al., 2008). After at least 20 rule conforming tones (standards), a further tone violated the established rule (deviant). In a control condition (eraser), the same auditory stimuli without rule, that is, without feature contingency was presented. We recorded the electrophysiological responses (EEG) to these auditory stimuli, and assessed cortical auditory processing by the means of long latency responses, namely the Mismatch Negativity (MMN) and subcortical auditory processing by the means of brainstem responses, namely the Frequency Following Response (FFR). In line with previous empirical findings, our preliminary results confirmed that rule violations elicited the MMN. Importantly, our results also seem to indicate significant differences in amplitude and power between FFR to deviant tones and FFR to standard and eraser tones. These results suggest that the auditory system extracts complex feature contingencies outside of the scope of cortical processing.