Figure 1.

Approach–avoidance conflict task. The 3 phases of the approach–avoidance conflict task are displayed in order from left to right. Left: During the decision-making phase, participants had 4 seconds to move the avatar (by moving a joystick) to a position that accurately reflected their preference of 2 potential outcomes. The position to which they moved the avatar determined the relative probability that each of the outcomes would occur (e.g., 90%:10% or 50%:50%). For approach–reward (APP) trials, participants were presented with a choice of 2 positive outcomes; 1 of the outcomes was paired with a 2-cent reward, as indicated by the filling of the red bar. For avoid–threat (AV) trials, participants were presented with a choice of a positive or negative outcome, and neither was paired with a reward. For conflict (CONF) trials, participants were presented with a choice of a positive outcome not paired with a reward and a negative outcome paired with a reward. The reward level was indicated by the level of filling of the red bar (2, 4 or 6 cents). Middle: During the affective outcome phase, participants were presented with a positive or negative affective stimulus picture and sound pairing. The pictures and sounds were drawn from the IAPS,⁴⁵ IADS⁴⁶ and other public-domain audio files. (The pictures displayed in this figure are from the public domain and not from IAPS to maintain stimulus novelty). Right: During the reward feedback phase, participants were presented with text indicating their level of reward for the trial (i.e., 0, 2, 4 or 6 cents), their total accumulated award and a trumpet sound when they received a reward (indicated by an asterisk). IADS = International Affective Digitized Sounds; IAPS = International Affective Picture System.