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Effects of Intensity of Facial Expressions on Amygdalar Activation Independently of Valence
For several stimulus categories (e.g., pictures, odors, and words), the arousal of both negative and positive stimuli has been shown to modulate amygdalar activation. In contrast, previous studies did not observe similar amygdalar effects in response to negative and positive facial expressions with...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Frontiers Media S.A.
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5167742/ https://www.ncbi.nlm.nih.gov/pubmed/28066216 http://dx.doi.org/10.3389/fnhum.2016.00646 |
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author | Lin, Huiyan Mueller-Bardorff, Miriam Mothes-Lasch, Martin Buff, Christine Brinkmann, Leonie Miltner, Wolfgang H. R. Straube, Thomas |
author_facet | Lin, Huiyan Mueller-Bardorff, Miriam Mothes-Lasch, Martin Buff, Christine Brinkmann, Leonie Miltner, Wolfgang H. R. Straube, Thomas |
author_sort | Lin, Huiyan |
collection | PubMed |
description | For several stimulus categories (e.g., pictures, odors, and words), the arousal of both negative and positive stimuli has been shown to modulate amygdalar activation. In contrast, previous studies did not observe similar amygdalar effects in response to negative and positive facial expressions with varying intensity of facial expressions. Reasons for this discrepancy may be related to analytical strategies, experimental design and stimuli. Therefore, the present study aimed at re-investigating whether the intensity of facial expressions modulates amygdalar activation by circumventing limitations of previous research. Event-related functional magnetic resonance imaging was used to assess brain activation while participants observed a static neutral expression and positive (happy) and negative (angry) expressions of either high or low intensity from an ecologically valid, novel stimulus set. The ratings of arousal and intensity were highly correlated. We found that amygdalar activation followed a u-shaped activation pattern with highest activation to high intense facial expressions as compared to low intensity facial expressions and to the neutral expression irrespective of valence, suggesting a critical role of the amygdala in valence-independent arousal processing of facial expressions. Additionally, consistent with previous studies, intensity effects were also found in visual areas and generally increased activation to angry versus happy faces were found in visual cortex and insula, indicating enhanced visual representations of high arousing facial expressions and increased visual and somatosensory representations of threat. |
format | Online Article Text |
id | pubmed-5167742 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-51677422017-01-06 Effects of Intensity of Facial Expressions on Amygdalar Activation Independently of Valence Lin, Huiyan Mueller-Bardorff, Miriam Mothes-Lasch, Martin Buff, Christine Brinkmann, Leonie Miltner, Wolfgang H. R. Straube, Thomas Front Hum Neurosci Neuroscience For several stimulus categories (e.g., pictures, odors, and words), the arousal of both negative and positive stimuli has been shown to modulate amygdalar activation. In contrast, previous studies did not observe similar amygdalar effects in response to negative and positive facial expressions with varying intensity of facial expressions. Reasons for this discrepancy may be related to analytical strategies, experimental design and stimuli. Therefore, the present study aimed at re-investigating whether the intensity of facial expressions modulates amygdalar activation by circumventing limitations of previous research. Event-related functional magnetic resonance imaging was used to assess brain activation while participants observed a static neutral expression and positive (happy) and negative (angry) expressions of either high or low intensity from an ecologically valid, novel stimulus set. The ratings of arousal and intensity were highly correlated. We found that amygdalar activation followed a u-shaped activation pattern with highest activation to high intense facial expressions as compared to low intensity facial expressions and to the neutral expression irrespective of valence, suggesting a critical role of the amygdala in valence-independent arousal processing of facial expressions. Additionally, consistent with previous studies, intensity effects were also found in visual areas and generally increased activation to angry versus happy faces were found in visual cortex and insula, indicating enhanced visual representations of high arousing facial expressions and increased visual and somatosensory representations of threat. Frontiers Media S.A. 2016-12-20 /pmc/articles/PMC5167742/ /pubmed/28066216 http://dx.doi.org/10.3389/fnhum.2016.00646 Text en Copyright © 2016 Lin, Mueller-Bardorff, Mothes-Lasch, Buff, Brinkmann, Miltner and Straube. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Neuroscience Lin, Huiyan Mueller-Bardorff, Miriam Mothes-Lasch, Martin Buff, Christine Brinkmann, Leonie Miltner, Wolfgang H. R. Straube, Thomas Effects of Intensity of Facial Expressions on Amygdalar Activation Independently of Valence |
title | Effects of Intensity of Facial Expressions on Amygdalar Activation Independently of Valence |
title_full | Effects of Intensity of Facial Expressions on Amygdalar Activation Independently of Valence |
title_fullStr | Effects of Intensity of Facial Expressions on Amygdalar Activation Independently of Valence |
title_full_unstemmed | Effects of Intensity of Facial Expressions on Amygdalar Activation Independently of Valence |
title_short | Effects of Intensity of Facial Expressions on Amygdalar Activation Independently of Valence |
title_sort | effects of intensity of facial expressions on amygdalar activation independently of valence |
topic | Neuroscience |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5167742/ https://www.ncbi.nlm.nih.gov/pubmed/28066216 http://dx.doi.org/10.3389/fnhum.2016.00646 |
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