Food & Paper: Auditory deviance detection in the human insula: An intracranial EEG study (Blenkmann)

Researcher at RITMO Alejandro Omar Blenkmann will give a talk on his latest paper.

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The human insula is an area of the brain that is rarely accessible due to its location behind the frontal and temporal lobes. Evidence from previous studies indicated that it is involved in auditory processing, but knowledge about its precise functional role and the underlying electrophysiology is limited. We decided to assess its role in automatic auditory deviance detection, a fundamental function of the human brain to detect a novel stimulus in a sequence of regular stimuli.
We analyzed the electrophysiological activity from 90 intracranial EEG channels implanted in the insular cortex across 16 patients undergoing pre-surgical monitoring for epilepsy treatment. Subjects passively listened to a stream of standard and deviant tones differing in four physical dimensions: intensity, frequency, location, or time. Responses to auditory stimuli were found in different areas of the insular cortex (the short and long gyri, and the anterior, superior, and inferior segments of the circular sulcus). Only a well-localized subset of channels (in the inferior segment of the circular sulcus) showed deviance detection responses. These results provide evidence that the human insula is engaged during auditory deviance detection. 


My major interest is how our brains make predictions of future events. Is our brain a prediction machine to some extent? Predictions are omnipresent in our lives. For example, when reading this text, our brains are predicting the following words. Or when playing tennis, we expect the ball to bounce off the ground in a precise way. However, we know little about how these predictions are implemented in our brains at the neurophysiological level. In my research, I use different experiments in the auditory sensory domain to characterize the neuronal networks that are active when we make predictions. And more interestingly, when unexpected events violate these predictions.
I'm interested in understanding the role of different brain areas during predictive processes and how they communicate with each other. I work mainly with intracranial recordings obtained from epilepsy patients, implanted for medical reasons with grids (ECoG) or depth electrodes (SEEG). These recordings allow us to observe the brain activity with a unique spatio-temporal resolution. I also study patients with frontal lobe lesions to better understand the role of the frontal lobe in the prediction network.
Additionally, I'm interested in methods for the localization of intracranial electrodes. In this vein, I developed iElectrodes, an open-source toolbox running on MATLAB ® to perform intracranial electrodes localization using MRI and CT images.
Published May 25, 2020 11:38 AM - Last modified May 25, 2020 11:38 AM