Negative cognitive biases are associated with the tendency to attend to and interpret ambiguous or neutral information in a negative manner. Cognitive bias modification (CBM) has shown experimental success in inducing a positive bias and reducing a negative bias. The present study will assess the impact of a CBM task design to induce a positive bias in the interpretation of ambiguous emotional expressions across measures of negative affect, the interpretation of faces and ambiguous emotional stimuli, automatic thinking, and motivation for rewards. Cognitive processing will also be considered while under threat of shock. All participants will be recruited from a healthy population and randomly allocated to either the intervention or sham intervention group.