Supplemental Materials To

Amygdala Reactivity, APD, and Psychopathy – Supplemental Materials 1

Supplemental Materials

Amygdala Reactivity and Negative Emotionality: Divergent Correlates of Antisocial Personality and Psychopathy Traits in a Community Sample

Supplemental Methods

Participants

Written informed consent according to the guidelines of the University of Pittsburgh’s institutional review board was provided by all subjects before their participation in the neuroimaging subcomponent of the AHAB registry.[1] All participants included in these analyses were in good general health and free of the following: (1) medical diagnoses of cancer, stroke, diabetes requiring insulin treatment, chronic kidney or liver disease, or a lifetime history of psychotic symptoms; (2) use of psychotropic, glucocorticoid, or cardiovascular (e.g., antihypertensive or antiarrhythmic) medication; (3) conditions that affect cerebral blood flow and metabolism (e.g., hypertension); and (4) any current DSM-IV Axis I disorder as assessed by the nonpatient version of the Structured Clinical Interview for DSM-IV (First, Spitzer, Gibbon, & Williams, 1996). For the current study, data from all 103 participants who underwent the neuroimaging component of the study and completed the NEO-PI-R were used in all analyses.

Procedures

Amygdala reactivity paradigm. Subject performance (accuracy and reaction time) was monitored during all scans. All blocks were preceded by a brief instruction (‘‘Match Faces’’ or ‘‘Match Shapes’’) lasting 2 s. In the face processing blocks, each of the six face trios was presented for 4 s with a variable interstimulus interval of 2 to 6 s (mean = 4 s) for a total block length of 48 s. In the sensorimotor control blocks, each of the six shape trios was presented for 4 s with a fixed interstimulus interval of 2 s for a total block length of 36 s. Total task time was 390 s. As we were not interested in neural networks associated with face-specific processing per se, but instead in eliciting a maximal amygdala response that we could then interrogate for individual differences that would be linked to personality dimensions, we chose not to use neutral faces as control stimuli. Additionally, neutral faces can be experienced as affectively laden or ambiguous and thus variably engage the amygdala (Schwartz, Wright, Shin, Kagan, & Rauch, 2003; Wright et al., 2003). However, our use of a variable interstimulus interval during face processing allows for the estimation of expression-specific neural activation.

BOLD fMRI acquisition parameters. All scanning parameters were selected to optimize the quality of the BOLD signal in the amygdala while maintaining a sufficient number of slices to acquire whole-brain data. Before collecting fMRI data for each participant, we acquired a reference echoplanar scan, which we visually inspected for artifacts (e.g., ghosting) and good signal across the entire volume of acquisition, including the amygdala. Additionally, autoshimming was conducted before the acquisition of BOLD data to minimize field inhomogeneities.

Regions of interest. We constructed separate regions of interest (ROIs) containing the amygdala’s basolateral complex (ventral amygdala) and central nucleus (dorsal amygdala) in each hemisphere using Marsbar (v 0.41). The ventral amygdala ROIs were anchored by MNI coordinates x = ±21, y = −3, z = −23, with widths of 14, 6, and 6 mm along the x-, y-, and z-axes, respectively. The total volume of the ventral amygdala was 1,024 mm3 in each hemisphere. The dorsal amygdala ROIs were anchored by the MNI coordinates x = ±21, y = −4, z = −13, with widths of 14, 8, and 10 mm along the x-, y-, and z-axes, respectively. The total volume of the dorsal amygdala was 1,920 mm3 in each hemisphere. The reported widths reflect the total for the ROI along each axis and are centered on the MNI coordinate anchoring each axis (i.e., with x = 21 and width = 14 mm, the range of coordinates included along that axis of the ROI are from x = 14 to x = 28). The posterior extent of both the dorsal and ventral amygdala was carefully defined to exclude the hippocampus. We also constructed a whole amygdala ROI using the Talairach Daemon option of the WFU PickAtlas Tool, version 1.04 (Wake Forest University School of Medicine, Winston-Salem, NC) with an additional 1× dilation to encompass the dorsal extended amygdala. We have successfully used this strategy of extracting these specific anatomically defined ROI values in previous research (Carré, Fisher, Manuck, & Hariri, 2012; Hyde, Manuck, & Hariri, 2011), demonstrating the utility of this approach and these ROI definitions.

Table S1

Characterization of APD and Psychopathy Scores From an Expert Profile Matching Count Method With the NEO-PR-R

Note: Bold items are those unique to each factor. Items with an R after are reverse scored. APD = antisocial personality disorder traits. NEO-PI-R domains are as follows: N = neuroticism, E = extraversion, O = openness, A = agreeableness, C = conscientiousness.

Table S2

Hierarchical Regressions of APD and Psychopathy Dimensions Predicting Amygdala Reactivity to Fearful Faces

N = 103. Unstandardized regression coefficients reported (B) with standardized coefficients (β) reported in the line below. Gender was controlled for the in the first step of all analyses. “Sobel” tests were used to examine the effect size of mutual suppression effects and significance (p < .05) is denoted from bootstrap bias corrected confidence intervals. +p < .10, *p < .05.

Table S3

Additional Study Variable Correlations

Note. Gender: 0 = male, 1 = female; Race: 0 = White, 1 = non-White. APD = antisocial personality disorder traits. MPQ = Multidimensional Personality Questionnaire. NEO = NEO-PI-R Personality Inventory. PCL = Psychopathy Checklist—Revised. PPI = Psychopathic Traits Inventory. Right and Left amygdala reactivity refer to extracted values based on the main effects of the all faces > shapes contrast.

*p < .05. **p < .01. ***p < .001.

Table S4

Hierarchical Regressions of NEO Derived PCL-R Factor 1 and Factor 2 Dimensions Predicting Amygdala Reactivity

Note. N = 103. Unstandardized regression coefficients reported (B) with standardized coefficients (β) reported in the line below. Gender was controlled for the in the first step of all analyses. “Sobel” tests were used to examine the effect size of mutual suppression effects and significance (p < .05) is denoted from bootstrap bias corrected confidence intervals. However, only two suppression tests reached significance (suppression of F1 by F2 predicting left dorsal amygdala reactivity anger > shapes contrast, z = 1.67, bootstrapped confidence interval did not contain 0; suppression of F2 by F1 in predicting right dorsal amygdala reactivity to fear > shapes contrast, z = 2.00, bootstrapped confidence interval did not contain 0) and thus these tests are not reported in the table. +p < .10. *p < .05. **p < .01

Table S5

Hierarchical Regressions of MPQ Derived PPI Fearless Dominance (F1) and Impulsive Antisociality (F2) Dimensions Predicting Amygdala Reactivity

Note. N = 103. Unstandardized regression coefficients reported (B) with standardized coefficients (β) reported in the line below. Gender was controlled for the in the first step of all analyses. The pattern of results was almost identical in initial regression steps when not controlling for the overlap of F1 and F2, thus only regressions controlling for their overlap are present. There are no instances of significant suppression relationships, thus these statistics are not provided. +p < .10. *p < .05. **p < .01.

References

Carré, J. M., Fisher, P. M., Manuck, S. B., & Hariri, A. R. (2012). Interaction between trait anxiety and trait anger predict amygdala reactivity to angry facial expressions in men but not women. Social Cognitive and Affective Neuroscience, 7, 213–221.

First, M. B., Spitzer, R. L., Gibbon, M., & Williams, J. B. W. (1996). Structured clinical interview for DSM-IV axis I disorders - patient edition. New York: Biometrics Research, New York State Psychiatric Institute.

Hyde, L. W., Manuck, S. B., & Hariri, A. R. (2011). Social support moderates the link between amygdala reactivity and trait anxiety. Neuropsychologia, 49, 651–656.

Schwartz, C. E., Wright, C. I., Shin, L. M., Kagan, J., & Rauch, S. L. (2003). Inhibited and uninhibited infants" grown up": adult amygdalar response to novelty. Science, 300, 1952–1953.

Wright, C. I., Martis, B., Schwartz, C. E., Shin, L. M., Fischer, H., McMullin, K., & Rauch, S. L. (2003). Novelty responses and differential effects of order in the amygdala, substantia innominata, and inferior temporal cortex. Neuroimage, 18, 660–669.