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Occipital and orbitofrontal hemodynamics during naturally paced reading: An fNIRS study

  • Humans typically read at incredibly fast rates, because they predict likely occurring words from a given context. Here, we used functional near-infrared spectroscopy (fNIRS) to track the ultra-rapid hemodynamic responses of words presented every 280 ms in a naturally paced sentence context. We found a lower occipital deoxygenation to unpredictable than to predictable words. The greater hemodynamic responses to unexpected words suggest that the visual features of expected words have been pre-activated previous to stimulus presentation. Second, we tested opposing theoretical proposals about the role of the medial orbitofrontal cortex (OFC): Either OFC may respond to the breach of expectation; or OFC is activated when the present stimulus matches the prediction. A significant interaction between word frequency and predictability indicated OFC responses to breaches of expectation for low- but not for high-frequency words: OFC is sensitive to both, bottom-up processing as mediated by word frequency, as well as top-down predictions.Humans typically read at incredibly fast rates, because they predict likely occurring words from a given context. Here, we used functional near-infrared spectroscopy (fNIRS) to track the ultra-rapid hemodynamic responses of words presented every 280 ms in a naturally paced sentence context. We found a lower occipital deoxygenation to unpredictable than to predictable words. The greater hemodynamic responses to unexpected words suggest that the visual features of expected words have been pre-activated previous to stimulus presentation. Second, we tested opposing theoretical proposals about the role of the medial orbitofrontal cortex (OFC): Either OFC may respond to the breach of expectation; or OFC is activated when the present stimulus matches the prediction. A significant interaction between word frequency and predictability indicated OFC responses to breaches of expectation for low- but not for high-frequency words: OFC is sensitive to both, bottom-up processing as mediated by word frequency, as well as top-down predictions. Particularly, when a rare word is unpredictable, OFC becomes active. Finally, we discuss how a high temporal resolution can help future studies to disentangle the hemodynamic responses of single trials in such an ultra-rapid event succession as naturally paced reading. (C) 2014 Elsevier Inc. All rights reserved.show moreshow less

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Metadaten
Author:Markus J. Hofmann, Michael Dambacher, Arthur M. Jacobs, Reinhold KlieglORCiDGND, Ralph Radach, Lars Kuchinke, Michael M. Plichta, Andreas J. Fallgatter, Martin J. Herrmann
DOI:https://doi.org/10.1016/j.neuroimage.2014.03.014
ISSN:1053-8119 (print)
ISSN:1095-9572 (online)
Pubmed Id:http://www.ncbi.nlm.nih.gov/pubmed?term=24642288
Parent Title (English):NeuroImage : a journal of brain function
Publisher:Elsevier
Place of publication:San Diego
Document Type:Article
Language:English
Year of first Publication:2014
Year of Completion:2014
Release Date:2017/03/27
Tag:Bayesian brain; Cloze probability; Frontopolar; Orbitofrontal; Predictive coding
Volume:94
Pagenumber:10
First Page:193
Last Page:202
Funder:Deutsche Forschungsgemeinschaft [JA 823/4-1, JA 823/4-2, HO5139/2-1]
Organizational units:Humanwissenschaftliche Fakultät / Institut für Psychologie
Peer Review:Referiert