Neural correlates of a computerized attention modification program in anxious subjects

Abstract

Computerized attention modification is a relatively new and empirically validated treatment approach for different types of anxiety disorders. However, its neural basis and processes involved are poorly understood. This study examined the effect of a one-time application of an attention modification program (AMP) on neural substrates underlying emotion processing in individuals with high social anxiety. Fourteen individuals with elevated social anxiety symptoms completed an emotional face processing task during functional magnetic resonance imaging before and after AMP, and were subsequently exposed to a laboratory stressor. Results revealed the following: First, there was attenuated activation from pre- to post-AMP in the bilateral amygdala, bilateral insula and subgenual anterior cingulate cortex. Second, post-AMP, individuals exhibited increased activation in several regions of the prefrontal cortex (PFC). Third, those individuals with greater enhancement of ventromedial PFC activation after AMP showed diminished attentional allocation for threat and attenuated anxiety reactivity to the stressor. We conclude that AMP exerts effects that are similar to those previously reported for standard anxiolytics; however, it also appears to foster deployment of top-down brain processes aimed to regulate anxiety.

Fig. 1

Sample trial of the AMP. On each trial, participants were presented with a fixation cross ‘+’ in the center of the monitor for 500 ms plus an additional jitter of 500–1000 ms (i.e. total fixation duration range = 1000–1500 ms). Following termination of the fixation cue, two faces of the same individual were presented, one face on top and one on bottom. Face pairs were neutral–threat (80% of trials) or neutral–neutral (20% of trials). After 500 ms, a probe (either the letter ‘E’ or ‘F’) appeared in the location of one of the two faces. Participants were instructed to identify whether the letter was an E or an F by pressing the corresponding button (left or right) on the response box. The probe remained on the screen until participants responded, after which the next trial began.

Fig. 2

Emotional Face Processing Task. Sample trials for the face-matching condition (a) and shape-matching (control) condition (b). During each 5-s trial, participants were instructed to press the left or right key on a button box to indicate which of two response options presented at the bottom of the screen matched the target at the top of the screen.

Fig. 3

Change in state anxiety throughout the experimental procedures. Participants did not differ in state anxiety from baseline to post-AMP. However, participants experienced a significant increase in anxiety from post-AMP to postspeech. Error bars represent ±1 SE.

Fig. 4

Change in fMRI–BOLD activation on the Emotion Face Assessment Task from pre- to post-AMP in a priori ROI. Attentional training attentuated activation within the bilateral amygdala (shown at y = −9), bilateral insula (shown at z = 16 for right insula and z = 0 for left insula) and sgACC (shown at x = −6) (a), and increased activation in the vmPFC (shown at x = −2) and vmPFC/OFC (shown at x = −4) (b) for processing of emotional faces relative to shapes. Error bars represent ±1 SE.

Fig. 5

Brain–behavior relationships. (a) The vmPFC (x = 0, y = 40, z = −3) showed significantly greater activation post-AMP relative to pre-AMP during emotional face processing. The difference in extracted PSC (face-shape contrast) in the vmPFC from before to after AMP (post- minus pre-PSC) was negatively associated with change in incongruent vs neutral bias scores [postbias minus prebias; rho(14) = −0.622, P = 0.018] and anxiety reactivity to the speech challenge (postspeech anxiety ratings minus prespeech anxiety ratings; rho(13) = −0.654, P = 0.015). (b) The bilateral amygdala (right amygdala; x = 27, y = −7, z = 17 and left amygdala; x = −24, y = −9, z = −14) showed significantly less activation post-AMP relative to pre-AMP during emotional face processing. The difference in extracted PSC (face-shape contrast) in the bilateral amygdala was positively associated with anxiety reactivity to the speech challenge, [rho(13) = 0.604, P = 0.029].