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The role of the amygdala in the perception of positive emotions: an "intensity detector".

Bonnet L, Comte A, Tatu L, Millot JL, Moulin T, Medeiros de Bustos E - Front Behav Neurosci (2015)

Bottom Line: We demonstrated that the left and right amygdalae were sensitive to changes in emotional intensity, activating more in response to stimuli with higher intensity.Furthermore, electrodermal responses were more frequent for the most intense stimuli, demonstrating the concomitant activation of the autonomic nervous system.These results highlight the sensitivity of the amygdala to the intensity of positively valenced visual stimuli, and in conjunction with results in the literature on negative emotions, reinforce the role of the amygdala in the perception of intensity.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Besancon University Hospital Besancon, France ; Department of Research in Functional Imaging, CIC 808, Besancon University Hospital Besancon, France ; Laboratory of Integrative and Clinical Neuroscience, EA 481, SFR FED 4234 UFC-CHRU-EFS Besancon, France.

ABSTRACT
The specific role of the amygdala remains controversial even though the development of functional imaging techniques has established its implication in the emotional process. The aim of this study was to highlight the sensitivity of the amygdala to emotional intensity (arousal). We conducted an analysis of the modulation of amygdala activation according to variation in emotional intensity via an fMRI event-related protocol. Monitoring of electrodermal activity, a marker of psychophysiological emotional perception and a reflection of the activation of the autonomic nervous system, was carried out concurrently. Eighteen subjects (10 men; aged from 22 to 29 years) looked at emotionally positive photographs. We demonstrated that the left and right amygdalae were sensitive to changes in emotional intensity, activating more in response to stimuli with higher intensity. Furthermore, electrodermal responses were more frequent for the most intense stimuli, demonstrating the concomitant activation of the autonomic nervous system. These results highlight the sensitivity of the amygdala to the intensity of positively valenced visual stimuli, and in conjunction with results in the literature on negative emotions, reinforce the role of the amygdala in the perception of intensity.

No MeSH data available.


(A) Distribution of the mean intensity ratings by our subjects for each of the 75 selected IAPS pictures against the IAPS norms of intensity. R, correlation coefficient (Pearson test, p < 0.001). (B) Distribution of the mean intensity ratings by our subjects for each of the 75 selected IAPS pictures against the IAPS norms of valence. Dashed lines represent the mean valence (m = 5.9) and the mean ± 1.96 SD (4.94 and 6.87). Blue (or respectively red/green) points form the low (or respectively medium/high) intensity groups. Points with a black edge represent the means of the sub-groups. Error bars are the standard error of the mean.
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Figure 1: (A) Distribution of the mean intensity ratings by our subjects for each of the 75 selected IAPS pictures against the IAPS norms of intensity. R, correlation coefficient (Pearson test, p < 0.001). (B) Distribution of the mean intensity ratings by our subjects for each of the 75 selected IAPS pictures against the IAPS norms of valence. Dashed lines represent the mean valence (m = 5.9) and the mean ± 1.96 SD (4.94 and 6.87). Blue (or respectively red/green) points form the low (or respectively medium/high) intensity groups. Points with a black edge represent the means of the sub-groups. Error bars are the standard error of the mean.

Mentions: Ratings made by our subjects were strongly correlated to IAPS norms of intensity (r = 0.80; p < 0.001) (Figure 1A). The ratings made by the subjects were slightly lower than the norms of the IAPS by 0.5 points (p < 0.001, paired t-test between IAPS ratings and mean ratings from our subjects). We built three groups of 25 visual stimuli according to the mean ratings of intensity performed by subjects: Group 1 (low intensity, m = 2.28), Group 2 (moderate intensity, m = 4), and Group 3 (high intensity, m = 5.8). Mean ratings of intensity were statistically different between each group of stimuli (Kruskall-Wallis p < 0.001). There was no significant difference between the mean valence of each group (Kruskall-Wallis, p = 0.13) (Figure 1B).


The role of the amygdala in the perception of positive emotions: an "intensity detector".

Bonnet L, Comte A, Tatu L, Millot JL, Moulin T, Medeiros de Bustos E - Front Behav Neurosci (2015)

(A) Distribution of the mean intensity ratings by our subjects for each of the 75 selected IAPS pictures against the IAPS norms of intensity. R, correlation coefficient (Pearson test, p < 0.001). (B) Distribution of the mean intensity ratings by our subjects for each of the 75 selected IAPS pictures against the IAPS norms of valence. Dashed lines represent the mean valence (m = 5.9) and the mean ± 1.96 SD (4.94 and 6.87). Blue (or respectively red/green) points form the low (or respectively medium/high) intensity groups. Points with a black edge represent the means of the sub-groups. Error bars are the standard error of the mean.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493392&req=5

Figure 1: (A) Distribution of the mean intensity ratings by our subjects for each of the 75 selected IAPS pictures against the IAPS norms of intensity. R, correlation coefficient (Pearson test, p < 0.001). (B) Distribution of the mean intensity ratings by our subjects for each of the 75 selected IAPS pictures against the IAPS norms of valence. Dashed lines represent the mean valence (m = 5.9) and the mean ± 1.96 SD (4.94 and 6.87). Blue (or respectively red/green) points form the low (or respectively medium/high) intensity groups. Points with a black edge represent the means of the sub-groups. Error bars are the standard error of the mean.
Mentions: Ratings made by our subjects were strongly correlated to IAPS norms of intensity (r = 0.80; p < 0.001) (Figure 1A). The ratings made by the subjects were slightly lower than the norms of the IAPS by 0.5 points (p < 0.001, paired t-test between IAPS ratings and mean ratings from our subjects). We built three groups of 25 visual stimuli according to the mean ratings of intensity performed by subjects: Group 1 (low intensity, m = 2.28), Group 2 (moderate intensity, m = 4), and Group 3 (high intensity, m = 5.8). Mean ratings of intensity were statistically different between each group of stimuli (Kruskall-Wallis p < 0.001). There was no significant difference between the mean valence of each group (Kruskall-Wallis, p = 0.13) (Figure 1B).

Bottom Line: We demonstrated that the left and right amygdalae were sensitive to changes in emotional intensity, activating more in response to stimuli with higher intensity.Furthermore, electrodermal responses were more frequent for the most intense stimuli, demonstrating the concomitant activation of the autonomic nervous system.These results highlight the sensitivity of the amygdala to the intensity of positively valenced visual stimuli, and in conjunction with results in the literature on negative emotions, reinforce the role of the amygdala in the perception of intensity.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Besancon University Hospital Besancon, France ; Department of Research in Functional Imaging, CIC 808, Besancon University Hospital Besancon, France ; Laboratory of Integrative and Clinical Neuroscience, EA 481, SFR FED 4234 UFC-CHRU-EFS Besancon, France.

ABSTRACT
The specific role of the amygdala remains controversial even though the development of functional imaging techniques has established its implication in the emotional process. The aim of this study was to highlight the sensitivity of the amygdala to emotional intensity (arousal). We conducted an analysis of the modulation of amygdala activation according to variation in emotional intensity via an fMRI event-related protocol. Monitoring of electrodermal activity, a marker of psychophysiological emotional perception and a reflection of the activation of the autonomic nervous system, was carried out concurrently. Eighteen subjects (10 men; aged from 22 to 29 years) looked at emotionally positive photographs. We demonstrated that the left and right amygdalae were sensitive to changes in emotional intensity, activating more in response to stimuli with higher intensity. Furthermore, electrodermal responses were more frequent for the most intense stimuli, demonstrating the concomitant activation of the autonomic nervous system. These results highlight the sensitivity of the amygdala to the intensity of positively valenced visual stimuli, and in conjunction with results in the literature on negative emotions, reinforce the role of the amygdala in the perception of intensity.

No MeSH data available.