| Reference code: | PT/FB/BL-2006-094.23 |
| Location: | Arquivo PCA - Pasta 21/2006
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Title:
| Skin conductance responses evoked by emotional faces reflect separable stimulus duration and awareness effects
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| Publication year: | 2010
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URL:
| Visitante: / http://fens2010.neurosciences.asso.fr/abstracts/R1/A023_2.html
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| Abstract/Results: | ABSTRACT:
It has been shown that faces displaying threat signals can be processed without awareness. This supports the existence of a subcortical pathway for rapid but coarse threat detection including the amygdala.
Here we study whether subliminal perception of faces showing neutral, happiness and anger expressions can elicit changes in the skin conductance response (SCR). Crucially, faces were presented at one of 5 durations (12, 24, 35, 170 and 2000 msec) to account for inter-subject variability in awareness thresholds, being immediately preceded and followed by two scrambled masks (forward + backward masking). In the end of each trial, participants (N=17) had to report the degree of awareness (unawareness of any content - faces and emotional features; face detection, or emotion discrimination), and to make arousal ratings (0 to 5) and valence categorizations (positive, negative or neutral).
The SCR magnitude measure showed no clear differences across emotion type or awareness level. A significant effect emerged only when contrasting emotion (anger + happiness) vs. neutral categories, but only when subjects reported emotion discrimination. No such effect was evident in the lower awareness levels. Importantly, the SCR differed across duration, with the emotion vs. neutral contrast showing significant differences only for the highest (2000 msec) duration. No significant differences were found for any of the shorter durations, not even when awareness was clearly reported (e. g. 165 msec). Conversely, differences in subjective arousal emerged as soon as subjects reported emotion discrimination, independent of duration (e. g. 24 msec).
Our data shows that duration explains modulations of the SCR better than awareness levels. This suggests that the SCR is not a specific measure for threat detection under unaware conditions but that it is dependent on conscious processing and higher cognitive functions.
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| Accessibility: | Document does not exist in file
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Language:
| eng
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Author:
| Almeida, I.
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Secondary author(s):
| Van Asselen, M., Castelo-Branco, M.
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Document type:
| Online abstract
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Number of reproductions:
| 1
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Reference:
| Almeida, I., Van Asselen, M., & Castelo-Branco, M. (2010, July). Skin conductance responses evoked by emotional faces reflect separable stimulus duration and awareness effects. Poster presented at the 7th FENS Forum of European Neuroscience, Amsterdam, Netherlands. Abstract retrieved from http://fens2010.neurosciences.asso.fr/abstracts/R1/A023_2.html |
| Indexed document: | No
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| Keywords: | Facial expression / Skin conductance response (SCR) / Arousal
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Skin conductance responses evoked by emotional faces reflect separable stimulus duration and awareness effects |