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The effect of threat on novelty evoked amygdala responses.

Balderston NL, Schultz DH, Helmstetter FJ - PLoS ONE (2013)

Bottom Line: Surprisingly, we found that novel images of snakes and flowers evoke more amygdala activity than repeated images of snakes and flowers.Our results further confirm the robustness of the novelty evoked amygdala responses, even when compared with effects more traditionally associated with the amygdala.In addition, our results suggest that threatening stimuli may prime the amygdala to respond to other types of stimuli as well.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, United States of America.

ABSTRACT
A number of recent papers have suggested that the amygdala plays a role in the brain's novelty detection circuit. In a recent study, we showed that this role may be specific to certain classes of biologically-relevant stimuli, such as human faces. The purpose of the present experiment was to determine whether other biologically-relevant stimuli also evoke novelty specific amygdala responses. To test this idea, we presented novel and repeated images of snakes and flowers while measuring BOLD. Surprisingly, we found that novel images of snakes and flowers evoke more amygdala activity than repeated images of snakes and flowers. Our results further confirm the robustness of the novelty evoked amygdala responses, even when compared with effects more traditionally associated with the amygdala. In addition, our results suggest that threatening stimuli may prime the amygdala to respond to other types of stimuli as well.

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Related in: MedlinePlus

Snakes were perceived as more threatening, and evoked larger SCRs than flowers.(a) Participants rated snakes as more likely to predict an electrical stimulation than flowers. (b) Participants showed larger SCRs to snake images than flower images. Participants also showed larger SCRs to novel images than to repeated images. (SCR = skin conductance response, NS = novel snake, RS = repeated snake, NF = novel flower, RF = repeated flower).
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pone-0063220-g005: Snakes were perceived as more threatening, and evoked larger SCRs than flowers.(a) Participants rated snakes as more likely to predict an electrical stimulation than flowers. (b) Participants showed larger SCRs to snake images than flower images. Participants also showed larger SCRs to novel images than to repeated images. (SCR = skin conductance response, NS = novel snake, RS = repeated snake, NF = novel flower, RF = repeated flower).

Mentions: Although amygdala responses seemed to be most sensitive to novelty, behavioral responses tended to differ based on stimulus type. Snakes were more rated as more arousing (M (SEM); Snake = 6.56 (0.245); Flower = 4.084 (0.359); t(17) = 5.153, p<0.0005), and negative (M (SEM); Snake = 6.902 (0.376); Flower = 3.700 (0.314); t(17) = 5.195, p = 0. 0005) than flowers. Likewise, subjects were more likely to expect an aversive outcome while viewing a snake than while viewing a flower (F(1,17) = 5.195; p = 0.036; See Figure 5a), and Across trials individuals learned to associate the picture with the absence of shock (F(1,4) = 2.717; p = 0.037). In addition to explicit responding, snakes also evoked larger SCRs than flowers as well (F(1,17) = 7.866; p = 0.012; See Figure 5b), even though there was a trend for SCRs to decrease in magnitude across trials (F(4.17) = 2.148; p = 0.084). Additionally, novel stimuli evoked larger SCRs than repeated stimuli (F(1,17) = 5.737; p = 0.028).


The effect of threat on novelty evoked amygdala responses.

Balderston NL, Schultz DH, Helmstetter FJ - PLoS ONE (2013)

Snakes were perceived as more threatening, and evoked larger SCRs than flowers.(a) Participants rated snakes as more likely to predict an electrical stimulation than flowers. (b) Participants showed larger SCRs to snake images than flower images. Participants also showed larger SCRs to novel images than to repeated images. (SCR = skin conductance response, NS = novel snake, RS = repeated snake, NF = novel flower, RF = repeated flower).
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3643910&req=5

pone-0063220-g005: Snakes were perceived as more threatening, and evoked larger SCRs than flowers.(a) Participants rated snakes as more likely to predict an electrical stimulation than flowers. (b) Participants showed larger SCRs to snake images than flower images. Participants also showed larger SCRs to novel images than to repeated images. (SCR = skin conductance response, NS = novel snake, RS = repeated snake, NF = novel flower, RF = repeated flower).
Mentions: Although amygdala responses seemed to be most sensitive to novelty, behavioral responses tended to differ based on stimulus type. Snakes were more rated as more arousing (M (SEM); Snake = 6.56 (0.245); Flower = 4.084 (0.359); t(17) = 5.153, p<0.0005), and negative (M (SEM); Snake = 6.902 (0.376); Flower = 3.700 (0.314); t(17) = 5.195, p = 0. 0005) than flowers. Likewise, subjects were more likely to expect an aversive outcome while viewing a snake than while viewing a flower (F(1,17) = 5.195; p = 0.036; See Figure 5a), and Across trials individuals learned to associate the picture with the absence of shock (F(1,4) = 2.717; p = 0.037). In addition to explicit responding, snakes also evoked larger SCRs than flowers as well (F(1,17) = 7.866; p = 0.012; See Figure 5b), even though there was a trend for SCRs to decrease in magnitude across trials (F(4.17) = 2.148; p = 0.084). Additionally, novel stimuli evoked larger SCRs than repeated stimuli (F(1,17) = 5.737; p = 0.028).

Bottom Line: Surprisingly, we found that novel images of snakes and flowers evoke more amygdala activity than repeated images of snakes and flowers.Our results further confirm the robustness of the novelty evoked amygdala responses, even when compared with effects more traditionally associated with the amygdala.In addition, our results suggest that threatening stimuli may prime the amygdala to respond to other types of stimuli as well.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, United States of America.

ABSTRACT
A number of recent papers have suggested that the amygdala plays a role in the brain's novelty detection circuit. In a recent study, we showed that this role may be specific to certain classes of biologically-relevant stimuli, such as human faces. The purpose of the present experiment was to determine whether other biologically-relevant stimuli also evoke novelty specific amygdala responses. To test this idea, we presented novel and repeated images of snakes and flowers while measuring BOLD. Surprisingly, we found that novel images of snakes and flowers evoke more amygdala activity than repeated images of snakes and flowers. Our results further confirm the robustness of the novelty evoked amygdala responses, even when compared with effects more traditionally associated with the amygdala. In addition, our results suggest that threatening stimuli may prime the amygdala to respond to other types of stimuli as well.

Show MeSH
Related in: MedlinePlus