Supplementary Information for

Dissociable roles for hippocampal and amygdalar volume in human fear conditioning

Raffaele Cacciaglia*, Sebastian T. Pohlack*, Herta Flor, & Frauke Nees**

Department of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim / HeidelbergUniversity, Mannheim, Germany

*These authors contributed equally to this work

**Corresponding author

**Correspondence:

Frauke Nees, Ph.D.

Department of Cognitive and Clinical Neuroscience,

Central Institute of Mental Health,

Square J5, 68159 Mannheim - Germany.

Phone: +49 621 17036306

Fax: +49 621 17036305

Email:

Supplementary results

Self-reported arousal

For ratings of subjective arousal, significant effects of CS type (F1,51 = 46.38, P < 0.001), phase (F3,153 = 13.88, P = 0.001), and CS type x phase (F3,153 = 22.16, P < 0.001) were found. During habituation no significant CS+/CS- differentiation was observed. CS+ and CS- differed significantly for early (t102 = 7.49, P < 0.001) and late acquisition (t102= 6.79, P < 0.001) as well as for extinction (t102 = 2.55, P = 0.01), indicating that the CS+ was reported being significantly more arousing than the CS- (Supplementary Fig. 1a).

Emotional valence

For emotional valence, CS type (F1,51 = 45.71, P < 0.001), phase (F3,153 = 11.67, P = 0.001), and CS type x phase (F3,153 = 39.92, P < 0.001) were significant. Follow-up analyses revealed no significant CS+/CS- differentiation for habituation or extinction. By contrast, CS+ was reported as being significantly more unpleasant during early (t102 = 9.97, P < 0.001) and late acquisition (t102 = 11.01, P < 0.001), indicating more unpleasant ratings for the CS+ than the CS- (Supplementary Fig. 1b).

Supplementary Figure 1

Verbal ratings of subjective arousal and emotional valence.

a) The CS+ was evaluated as significantly more arousing than the CS- in both early and late acquisition phases, as well as during extinction. b) The CS+ was evaluated as significantly more unpleasant than the CS- during both early and late acquisition phases. Error bars represent standard error of the mean (s.e.m). ***P < 0.001 ** P < 0.01.

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Supplementary Table 1. Regression results.Standardized beta coefficients indexing the linear relationship betweengroup mean amygdalar volume and ratings of CS-US contingency in each conditioning phase (habituation data not shown). P-values are reported into brackets.

Acq1 / Acq2 / Ext
CS+* / CS- / CS+* - CS- / CS+* / CS- / CS+* - CS- / CS+* / CS- / CS+* - CS-
rAMGv / -0.061
(0.665) / 0.142
(0.315) / -0.121
(0.394) / 0.087
(0.541) / -0.163
(0.248) / 0.167
(0.238) / 0.166
(0.239) / 0.226
(0.107) / -0.016
(0.912)
lAMGv / 0.067
(0.635) / -0.044
(0.758) / 0.059
(0.680) / 0.025
(0.860) / 0.215
(0.127) / 0.175
(0.214) / 0.101
(0.476) / -0.014
(0.923) / 0.109
(0.442)

Acq1: early acquisition; Acq2: late acquisition;CS: conditioned stimulus; Ext: extinction; lAMGv: left amygdalar volume; rAMGv: right amygdalar volume; US: unconditioned stimulus. *unpaired CS+

Supplementary Table 2. Regression results.Standardized beta coefficients indicating the linear relationship between group mean hippocampal volume andSCR amplitudesin each conditioning phase (habituation data not shown). P-values are reported into round brackets

Acq1 / Acq2 / Ext
CS+* / CS- / CS+* - CS- / CS+* / CS- / CS+* - CS- / CS+* / CS- / CS+* - CS-
rHCv / -0.002
(0.991) / -0.039
(0.783) / 0.013
(0.928) / -0.030
(0.833) / -0.069
(0.625) / -0.006
(0.964) / -0.038
(0.788) / 0.008
(0.956) / -0.033
(0.819)
lHCv / 0.173
(0.221) / 0.158
(0.264) / 0.126
(0.375) / 0.082
(0.565) / 0.083
(0.561) / 0.053
(0.711) / -0.124
(0.380) / 0.136
(0.336) / -0.056
(0.693)

Acq1: early acquisition; Acq2: late acquisition; Ext: extinction; lHCv: left hippocampal volume; rHCv: right hippocampal volume

*unpaired CS+

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