No effect of very brief exposure to masked food pictures on fear of food in anorexia nervosa

Advancing the treatment of anxiety disorders in transition-age youth: a review of the therapeutic effects of unconscious exposure

BACKGROUND

The real-world effectiveness of exposure-based therapies for youth depends on the willingness and ability of young people to tolerate confronting their fears, which can be experienced as highly aversive and create problems with treatment engagement and acceptance. Recently, neuroscientific research on the nonconscious basis of fear has been translated into novel exposure interventions that bypass conscious processing of feared stimuli and that thus do not cause phobic youth to experience distress. We present a review of these unconscious exposure interventions.

METHODS

A PRISMA-based search yielded 20 controlled experiments based on three paradigms that tested if fear-related responses could be reduced without conscious awareness in highly phobic, transition-age youth: 14 randomized controlled trials (RCTs), 5 fMRI studies (1 was also an RCT), 4 psychophysiological studies (3 were also RCTs), and 1 ERP study. We conducted meta-analyses of outcomes where feasible.

RESULTS

Unconscious exposure interventions significantly (1) reduced avoidance behavior (range of Cohen's d = 0.51-0.95) and self-reported fear (d = 0.45-1.25) during in vivo exposure to the feared situation; (2) reduced neurobiological indicators of fear (d = 0.54-0.62) and concomitant physiological arousal (d = 0.55-0.64); (3) activated neural systems supporting fear regulation more strongly than visible exposure to the same stimuli (d = 1.2-1.5); (4) activated regions supporting fear regulation that mediated the reduction of avoidance behavior (d = 0.70); (5) evoked ERPs suggesting encoding of extinction memories (d = 2.13); and (6) had these effects without inducing autonomic arousal or subjective fear.

CONCLUSIONS

Unconscious exposure interventions significantly reduce a variety of symptomatic behaviors with mostly moderate effect sizes in transition-age youth with specific phobias. fMRI and physiological findings establish a neurophysiological basis for this efficacy, and suggest it occurs through extinction learning. Unconscious exposure was well tolerated, entirely unassociated with drop out, and is highly scalable for clinical practice. However, a number of limitations must be addressed to assess potential clinical impacts, including combining unconscious exposure with exposure therapy to boost treatment acceptance and efficacy.

The effectiveness of a masked counterconditioning approach using continuous flash suppression to alleviate body dissatisfaction in women with high body image concerns

BACKGROUND AND OBJECTIVES

Research that used counterconditioning (CC) to reduce women's negative body image has led to mixed results. One explanation could be that the negative responses elicited by own body pictures hinder the effectiveness of CC procedures in adjusting overly negative attitudes towards the own body. In this study we therefore tried to prevent the impact of negative responses by limiting women's perceptual awareness of the own body pictures during the CC procedure.

METHODS

Women with a negative body image were randomly assigned to an experimental (n = 75) or control (n = 71) condition. In the experimental condition, participants' masked body pictures were systematically followed by visible social approval cues (i.e., smiling faces), whereas neutral body-unrelated control pictures were followed by a blank screen. In the control condition, both own body and control pictures were followed by a blank screen.

RESULTS

Participants in the experimental condition did not report a more positive evaluation of the own body (pictures) after CC than participants in the control condition. Also, the strength of automatic affective body evaluations as indexed by a single-target Implicit Association Test did not differ between conditions.

LIMITATIONS

Many participants did not remain fully unaware of their body pictures during conditioning.

CONCLUSIONS

The findings provided no support for the idea that CC with masked own body pictures can be used in women with body dissatisfaction to improve their body image.