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Affective blindsight relies on low spatial frequencies.

  • Burra N Faculty of Psychology and Educational Science, University of Geneva, Geneva, Switzerland.
  • Hervais-Adelman A Neuroscience Center, University of Geneva, Switzerland; Brain and Language Laboratory, University of Geneva Medical School, University of Geneva, CH-1211 Geneva, Switzerland.
  • Celeghin A Department of Medical and Clinical Psychology, and CoRPS - Center of Research on Psychology in Somatic diseases - Tilburg University, Tilburg, The Netherlands; Department of Psychology, University of Turin, Turin, Italy.
  • de Gelder B Brain and Emotion Laboratory, Maastricht University, Maastricht, The Netherlands.
  • Pegna AJ School of Psychology, The University of Queensland, Saint Lucia, Brisbane Qld-4072, Australia. Electronic address: a.pegna@uq.edu.au.
  • 2017-10-11
Published in:
  • Neuropsychologia. - 2019
Affective blindsight
Amygdala
Facial expressions
Fear emotion
Hemianopia
Spatial frequency
Affect
Amygdala
Blindness, Cortical
Facial Expression
Facial Recognition
Fear
Humans
Magnetic Resonance Imaging
Male
Middle Aged
Stroke
Visual Cortex
Visual Pathways
Visual Perception
English The human brain can process facial expressions of emotions rapidly and without awareness. Several studies in patients with damage to their primary visual cortices have shown that they may be able to guess the emotional expression on a face despite their cortical blindness. This non-conscious processing, called affective blindsight, may arise through an intact subcortical visual route that leads from the superior colliculus to the pulvinar, and thence to the amygdala. This pathway is thought to process the crude visual information conveyed by the low spatial frequencies of the stimuli. In order to investigate whether this is the case, we studied a patient (TN) with bilateral cortical blindness and affective blindsight. An fMRI paradigm was performed in which fearful and neutral expressions were presented using faces that were either unfiltered, or filtered to remove high or low spatial frequencies. Unfiltered fearful faces produced right amygdala activation although the patient was unaware of the presence of the stimuli. More importantly, the low spatial frequency components of fearful faces continued to produce right amygdala activity while the high spatial frequency components did not. Our findings thus confirm that the visual information present in the low spatial frequencies is sufficient to produce affective blindsight, further suggesting that its existence could rely on the subcortical colliculo-pulvino-amygdalar pathway.
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  • English
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green
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https://sonar.ch/global/documents/232614
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