Neural Activation and Attention Bias to Emotional Faces in

Autism Spectrum Disorders

S.J. Weng, H. Louro, S.J. Peltier, J. Zaccagnini, L.I. Dayton, P. Bissett, W.J. Guthrie, S. Risi, C. Lord, C.S. Monk

Department of Psychology, University of Michigan, Ann Arbor, MI 48109

22 METHODSMETHODS

11 INTRODUCTIONINTRODUCTION 33 RESULTS RESULTS

66

55 PRELIMINARY CONCLUSIONSPRELIMINARY CONCLUSIONS

44 SUMMARYSUMMARY

This research was supported by 5K22MH068017-02(CSM), U19 HD35482 (CL), and MH066496 (CL)

PS2.13

FUTURE WORK

Behavioral Data (no group differences in attention)

fMRI Data17ms Face Presentation (masked)

500 ms Face Presentation

• A probe detection task was used to obtain measures of attention to faces.• In an event-related design, subjects viewed pairs of faces (angry/neutral,

sad/neutral, happy/neutral and neutral/neutral) for either 17 ms or 500 ms. • 17 ms face presentations were followed by scrambled faces (mask) to

restrict the awareness of the face.• Subjects responded by pressing a button to an asterisk that was either on

the same (congruent) or opposite (incongruent) side as the emotional face.• Reaction time differences between congruent and incongruent trials provide

a measure of attention bias to emotional faces.• A total of 36 randomized trials for each condition were included. • Only correct trials were included in the fMRI analysis.

fMRI Task

Participants• 6 Healthy Controls (5 males, 1 female)• 6 High-functioning ASD individuals (5 males, 1 female)• Diagnoses was based on a clinical psychologists administered ADOS, ADI and consensus best estimate diagnosis by two clinical psychologists.

  Controls mean (std.dev) ASD mean (std.dev) t(10) p value

Age 27 (7) 29 (9) 0.497 0.63

Verbal IQ 110.5 (14.10) 108 (11.17) 0.34 0.741

Nonverbal IQ 119 (12.13) 112.83 (13.20) 0.843 0.419

• The amygdala underlies social interaction and shows disturbed functioning in Autism Spectrum Disorders (ASD).

• However, the nature of the amygdala disturbance is inconsistent. • Some studies found that individuals with ASD showed less activation in

the amygdala in response to faces (Ashwin et al., 2006; Critchley et al., 2000; Dapretto et al., 2006; Gretlotti et al., 2005).

• Another study found that attention to faces (assessed with eye gaze) was positively associated with amygdala activation in individuals with ASD (Dalton et al., 2005).

• Thus, the lack of amygdala activation in ASD reported in previous studies may be due to reduced allocation of attention to faces.

Hypothesis• When group differences in attention are considered in the fMRI analysis,

subjects with ASD relative to controls will show greater amygdala activation to faces.

fMRI acquisitionT2 weighted BOLD images were acquired using a reverse spiral sequence of 40 contiguous 3mm slices (TR= 2000ms; TE= 30ms, flip angle= 80o; FOV= 22cm).

Control vs. ASD

Angry vs. Baseline

xyz: -25, 0, -12; t (10)= 4.77; p <0.05 (corrected)

Control vs. ASD

ASD only

xyz: 25, -7, -19; t (10)= 4.27; p <0.05 (corrected)

Baseline vs. Angry

Angry vs. Baseline

xyz: 25, -7, -21; t (10)= 4.24; p <0.05 (corrected)

Baseline vs. Sad

xyz: 29, -5, -18; t (10)= 4.95; p <0.05 (corrected)

xyz: 28, -5, -18; t (10)= 3.94; p <0.05 (corrected)

Sad vs. Baseline

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Contact Information: sweng@umich.edu

Controls

ASD

17 ms face presentation

500 ms face presentation

-20

-15

-10

-5

0

5

10

15

20

25

t (10)= 0.12p= 0.9

t (10)= 0.3p= 0.77

t (10)= -0.83p= 0.43

t (10)= -0.39p= 0.7

t (10)= -0.76p= 0.47

t (10)= -0.14p= 0.89

Att

en

tio

n B

ias

Angry Sad Happy

• In the 17 ms face presentation condition, controls relative to ASD show a bilateral increase in amygdala activation. •Most pronounced to angry faces.•Similar trends of activation to sad, neutral and happy faces.

• Collect data on additional participants • Examine effects in other areas of the brain:

• Orbital frontal cortex (OFC)• Fusiform• Nucleus accumbens

• Perform functional connectivity analysis between the amygdala and other structures. • Analyze resting connectivity data to further evaluate functioning of the amygdala during baseline.

(1) There are no significant differences of attention bias to specific emotional faces.

(2) When faces are briefly presented (17 ms), controls show greater amygdala activation relative to those with ASD. a) This is most pronounced to angry faces.b) Similar trends are seen for sad, neutral happy faces.

(3) When faces are presented for 500 ms, controls show greater amygdala activation relative to individuals with ASD. a) This is most pronounced to angry and sad

faces. b) Similar trends are noted for neutral and happy.(4) Individuals with ASD show greater activation to

baseline than to angry and sad faces (500 ms). a) This is most pronounced to angry and sad.

b) Similar trends are noted for neutral and happy.(5) Amygdala activation in (3) can be explained by

results seen in (4).

• Even when faces are briefly presented and awareness is restricted, ASD and controls show differential amygdala activation (controls > ASD), particularly to angry faces.

• When faces are presented for a longer duration (500 ms), ASD show greater activation to baseline than to faces, particularly angry and sad.

• Deactivation to faces?• Increased activation to baseline?

• In the 500 ms face presentation condition, controls relative to ASD show a increase in amygdala activation.• Most pronounced in angry and sad faces.• Similar trends of activation to neutral and happy faces.

• Effects are driven by the ASD group showing greater activation to the baseline than the emotional faces.

xyz: 25, -3, -12; t (10)= 4.14; p <0.05 (corrected)

Angry vs. Baseline

Note: In an awareness test, subjects performed at chance when asked to identify the facial expression when it was presented at 17 ms and masked. This suggests that awareness was restricted at the 17ms face presentation.