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Brief learning induces a memory bias for arousing-negative words: an fMRI study in high and low trait anxious persons.

Eden AS, Dehmelt V, Bischoff M, Zwitserlood P, Kugel H, Keuper K, Zwanzger P, Dobel C - Front Psychol (2015)

Bottom Line: The behavioral results demonstrate that associative word-learning leads to an explicit (but no implicit) memory bias for negatively linked pseudowords, relative to neutral ones, which confirms earlier studies.Bilateral amygdala activation underlines the behavioral effect: Higher trait anxiety is correlated with stronger amygdala activation for negatively linked pseudowords than for neutrally linked ones.Most interestingly, this effect is also present for negatively paired pseudowords that participants could not remember well.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biomagnetism and Biosignalanalysis, University Hospital of Münster Münster, Germany ; Institute of Psychology, University of Münster Münster, Germany.

ABSTRACT
Persons suffering from anxiety disorders display facilitated processing of arousing and negative stimuli, such as negative words. This memory bias is reflected in better recall and increased amygdala activity in response to such stimuli. However, individual learning histories were not considered in most studies, a concern that we meet here. Thirty-four female persons (half with high-, half with low trait anxiety) participated in a criterion-based associative word-learning paradigm, in which neutral pseudowords were paired with aversive or neutral pictures, which should lead to a valence change for the negatively paired pseudowords. After learning, pseudowords were tested with fMRI to investigate differential brain activation of the amygdala evoked by the newly acquired valence. Explicit and implicit memory was assessed directly after training and in three follow-ups at 4-day intervals. The behavioral results demonstrate that associative word-learning leads to an explicit (but no implicit) memory bias for negatively linked pseudowords, relative to neutral ones, which confirms earlier studies. Bilateral amygdala activation underlines the behavioral effect: Higher trait anxiety is correlated with stronger amygdala activation for negatively linked pseudowords than for neutrally linked ones. Most interestingly, this effect is also present for negatively paired pseudowords that participants could not remember well. Moreover, neutrally paired pseudowords evoked higher amygdala reactivity than completely novel ones in highly anxious persons, which can be taken as evidence for generalization. These findings demonstrate that few word-learning trials generate a memory bias for emotional stimuli, indexed both behaviorally and neurophysiologically. Importantly, the typical memory bias for emotional stimuli and the generalization to neutral ones is larger in high anxious persons.

No MeSH data available.


Related in: MedlinePlus

Coronal, sagittal and axial view depicting activation extension of one example contrast; supra-threshold voxels are shown in red. Region of interest (ROI)-analysis with trait anxiety as a covariate for the bilateral amygdala; contrast 1: Explicitly learned pseudowords > novel pseudo words (x = 32, y = 5, z = -21).
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Figure 3: Coronal, sagittal and axial view depicting activation extension of one example contrast; supra-threshold voxels are shown in red. Region of interest (ROI)-analysis with trait anxiety as a covariate for the bilateral amygdala; contrast 1: Explicitly learned pseudowords > novel pseudo words (x = 32, y = 5, z = -21).

Mentions: The ROI-analysis of the bilateral amygdala with trait anxiety as covariate revealed a significant contrast 1 (explicitly learned pseudowords vs. novel pseudowords, see Figure 3). Explicitly learned pseudowords elicited more amygdala activity than novel pseudowords in the bilateral amygdala, and this effect was positively related to measures of trait anxiety x = 32, y = 5, z = -21, t(32) = 2.62, k = 111 voxels, p = 0.007. Importantly, and contrary to the analysis without covariate, contrast 2 (less well-learned pseudowords vs. novel pseudowords) also yielded significant results x = 31, y = 2, z = -19, t(32) = 2.42, k = 77 voxels, p = 0.011, positively related to trait anxiety. Contrast 3 (arousing-negative pseudowords vs. neutral pseudowords) was also significant x = 34, y = -7, z = -11, t(32) = 2.74, k = 55 voxels, p = 0.005. Hence, arousing-negative pseudowords elicited more amygdala activity than neutral pseudowords, and this was positively related to trait anxiety. As in the analysis without covariate, contrast 4 (explicitly learned arousing pseudowords vs. less well-earned arousing pseudowords) was not significant. Contrast 5, comparing arousing-negative and neutral pseudowords that were not learned well, was significant x = 32, y = -7, z = -9, t(32) = 2.16, k = 47 voxels, p = 0.019. The arousing-negative pseudowords elicited more amygdala reactivity than the neutral pseudowords, again, positively related to measures of trait anxiety. Contrast 6 (less well-learned neutral pseudowords vs. novel pseudowords), however, was not significant. But contrast 7 (less well-learned arousing-negative pseudowords vs. novel pseudowords) and contrast 8 (neutral pseudowords vs. novel pseudowords), were highly significant (contrast 7: x = 31, y = 0, z = -23, t(33) = 3.25, k = 207 voxels, p < 0.001; contrast 8: x = 31, y = 4, z = -19, t(32) = 3.39, k = 116 voxels, p < 0.001. Hence, pseudowords that were less well learned elicited more amygdala reactivity than novel pseudowords, independent of the linked affect. This was positively related to measures of trait anxiety. See Table 2 for an overview of all regression analysis results and Figure 3 for a visualization of the spatial extension of amygdala activation of contrast 1.


Brief learning induces a memory bias for arousing-negative words: an fMRI study in high and low trait anxious persons.

Eden AS, Dehmelt V, Bischoff M, Zwitserlood P, Kugel H, Keuper K, Zwanzger P, Dobel C - Front Psychol (2015)

Coronal, sagittal and axial view depicting activation extension of one example contrast; supra-threshold voxels are shown in red. Region of interest (ROI)-analysis with trait anxiety as a covariate for the bilateral amygdala; contrast 1: Explicitly learned pseudowords > novel pseudo words (x = 32, y = 5, z = -21).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4543815&req=5

Figure 3: Coronal, sagittal and axial view depicting activation extension of one example contrast; supra-threshold voxels are shown in red. Region of interest (ROI)-analysis with trait anxiety as a covariate for the bilateral amygdala; contrast 1: Explicitly learned pseudowords > novel pseudo words (x = 32, y = 5, z = -21).
Mentions: The ROI-analysis of the bilateral amygdala with trait anxiety as covariate revealed a significant contrast 1 (explicitly learned pseudowords vs. novel pseudowords, see Figure 3). Explicitly learned pseudowords elicited more amygdala activity than novel pseudowords in the bilateral amygdala, and this effect was positively related to measures of trait anxiety x = 32, y = 5, z = -21, t(32) = 2.62, k = 111 voxels, p = 0.007. Importantly, and contrary to the analysis without covariate, contrast 2 (less well-learned pseudowords vs. novel pseudowords) also yielded significant results x = 31, y = 2, z = -19, t(32) = 2.42, k = 77 voxels, p = 0.011, positively related to trait anxiety. Contrast 3 (arousing-negative pseudowords vs. neutral pseudowords) was also significant x = 34, y = -7, z = -11, t(32) = 2.74, k = 55 voxels, p = 0.005. Hence, arousing-negative pseudowords elicited more amygdala activity than neutral pseudowords, and this was positively related to trait anxiety. As in the analysis without covariate, contrast 4 (explicitly learned arousing pseudowords vs. less well-earned arousing pseudowords) was not significant. Contrast 5, comparing arousing-negative and neutral pseudowords that were not learned well, was significant x = 32, y = -7, z = -9, t(32) = 2.16, k = 47 voxels, p = 0.019. The arousing-negative pseudowords elicited more amygdala reactivity than the neutral pseudowords, again, positively related to measures of trait anxiety. Contrast 6 (less well-learned neutral pseudowords vs. novel pseudowords), however, was not significant. But contrast 7 (less well-learned arousing-negative pseudowords vs. novel pseudowords) and contrast 8 (neutral pseudowords vs. novel pseudowords), were highly significant (contrast 7: x = 31, y = 0, z = -23, t(33) = 3.25, k = 207 voxels, p < 0.001; contrast 8: x = 31, y = 4, z = -19, t(32) = 3.39, k = 116 voxels, p < 0.001. Hence, pseudowords that were less well learned elicited more amygdala reactivity than novel pseudowords, independent of the linked affect. This was positively related to measures of trait anxiety. See Table 2 for an overview of all regression analysis results and Figure 3 for a visualization of the spatial extension of amygdala activation of contrast 1.

Bottom Line: The behavioral results demonstrate that associative word-learning leads to an explicit (but no implicit) memory bias for negatively linked pseudowords, relative to neutral ones, which confirms earlier studies.Bilateral amygdala activation underlines the behavioral effect: Higher trait anxiety is correlated with stronger amygdala activation for negatively linked pseudowords than for neutrally linked ones.Most interestingly, this effect is also present for negatively paired pseudowords that participants could not remember well.

View Article: PubMed Central - PubMed

Affiliation: Institute of Biomagnetism and Biosignalanalysis, University Hospital of Münster Münster, Germany ; Institute of Psychology, University of Münster Münster, Germany.

ABSTRACT
Persons suffering from anxiety disorders display facilitated processing of arousing and negative stimuli, such as negative words. This memory bias is reflected in better recall and increased amygdala activity in response to such stimuli. However, individual learning histories were not considered in most studies, a concern that we meet here. Thirty-four female persons (half with high-, half with low trait anxiety) participated in a criterion-based associative word-learning paradigm, in which neutral pseudowords were paired with aversive or neutral pictures, which should lead to a valence change for the negatively paired pseudowords. After learning, pseudowords were tested with fMRI to investigate differential brain activation of the amygdala evoked by the newly acquired valence. Explicit and implicit memory was assessed directly after training and in three follow-ups at 4-day intervals. The behavioral results demonstrate that associative word-learning leads to an explicit (but no implicit) memory bias for negatively linked pseudowords, relative to neutral ones, which confirms earlier studies. Bilateral amygdala activation underlines the behavioral effect: Higher trait anxiety is correlated with stronger amygdala activation for negatively linked pseudowords than for neutrally linked ones. Most interestingly, this effect is also present for negatively paired pseudowords that participants could not remember well. Moreover, neutrally paired pseudowords evoked higher amygdala reactivity than completely novel ones in highly anxious persons, which can be taken as evidence for generalization. These findings demonstrate that few word-learning trials generate a memory bias for emotional stimuli, indexed both behaviorally and neurophysiologically. Importantly, the typical memory bias for emotional stimuli and the generalization to neutral ones is larger in high anxious persons.

No MeSH data available.


Related in: MedlinePlus