Involuntary future projections are as frequent as involuntary memories, but more positive.

Mental time travel (MTT) is the ability to mentally project oneself into one's personal past or future, in terms of memories of past events or projections of possible future events. We investigated the frequency and valence of involuntary (spontaneously arising) MTT in the context of high trait worry. High (N=18) and low (N=16) worriers recorded the frequency and valence of involuntary memories and future projections using a structured notebook and completed measures probing individual differences related to negative affectivity. Involuntary future projections were as frequent as involuntary memories. We found a positivity bias for both past and future MTT, in that fewer negative events were reported than positive or neutral ones. This positivity bias was greater for future than for past events. Individual differences related to negative affectivity were positively associated with the proportion of negative events, indicating a reduced positivity bias in individuals with a general tendency to experience negative affect.