title: Occipital and orbitofrontal hemodynamics during naturally paced reading: an fNIRS study.
abstract: 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.
authors.affiliation: Department of Psychology, University of Wuppertal, Max-Horkheimer Str. 20, 42119 Wuppertal, Germany; Department of Psychology, Habelschwerdter Allee 45, 14195 Berlin, Germany; Dahlem Institute for Neuroimaging of Emotion (D.I.N.E.), Free University Berlin, Germany. Electronic address: mhofmann@uni-wuppertal.de.
authors.forename: Markus J
authors.initials: MJ
authors.lastname: Hofmann
authors.affiliation: Department of Psychology, University Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam, Germany. Electronic address: michael.dambacher@uni-konstanz.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Dambacher
authors.affiliation: Department of Psychology, Habelschwerdter Allee 45, 14195 Berlin, Germany; Dahlem Institute for Neuroimaging of Emotion (D.I.N.E.), Free University Berlin, Germany. Electronic address: ajacobs@zedat.fu-berlin.de.
authors.forename: Arthur M
authors.initials: AM
authors.lastname: Jacobs
authors.affiliation: Department of Psychology, University Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam, Germany. Electronic address: kliegl@uni-potsdam.de.
authors.forename: Reinhold
authors.initials: R
authors.lastname: Kliegl
authors.affiliation: Department of Psychology, University of Wuppertal, Max-Horkheimer Str. 20, 42119 Wuppertal, Germany. Electronic address: radach@uni-wuppertal.de.
authors.forename: Ralph
authors.initials: R
authors.lastname: Radach
authors.affiliation: Department of Psychology, Ruhr-University Bochum, Universitaetsstr. 150, 44780 Bochum, Germany. Electronic address: lars.kuchinke@rub.de.
authors.forename: Lars
authors.initials: L
authors.lastname: Kuchinke
authors.affiliation: Central Institute of Mental Health, Department of Psychiatry and Psychotherapy, Medical Faculty Mannheim, Heidelberg University, J5, 68159 Mannheim, Germany. Electronic address: michael.plichta@zi-mannheim.de.
authors.forename: Michael M
authors.initials: MM
authors.lastname: Plichta
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Tuebingen, Calwerstr. 14, 72076 Tuebingen, Germany; LEAD Graduate School, University of Tuebingen, Calwerstr. 14, 72076 Tuebingen, Germany; Department for Psychiatry, Psychosomatics and Psychotherapy, University Wuerzburg, Fuechsleinstr. 15, 97080 Wuerzburg, Germany. Electronic address: Andreas.Fallgatter@med.uni-tuebingen.de.
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Fallgatter
authors.affiliation: Department for Psychiatry, Psychosomatics and Psychotherapy, University Wuerzburg, Fuechsleinstr. 15, 97080 Wuerzburg, Germany. Electronic address: Herrmann_m@klinik.uni-wuerzburg.de.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Herrmann
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D001931:Brain Mapping / Q000379:methods*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D032882:Comprehension / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009778:Occipital Lobe / Q000502:physiology*; D010092:Oximetry / Q000379:methods; D010101:Oxygen Consumption / Q000502:physiology*; D017397:Prefrontal Cortex / Q000502:physiology*; D011932:Reading; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D013647:Task Performance and Analysis; D014796:Visual Perception / Q000502:physiology*
keywords: Bayesian brain; Cloze probability; Frontopolar; Orbitofrontal; Predictive coding