Choices about whether to wait: Changes in delay discounting without changes in time perception.

Delay discounting occurs when the present, subjective value of a reward decreases as a function of delay. Delay discounting is steeper when individuals must wait during the delay, and delay discounting rates for decisions about waiting are not strongly correlated with those for decisions about postponing without waiting. We examined whether changes in delay discounting in choices about waiting are linked to changes in subjective time perception. In Experiment 1, participants completed an experiential waiting task twice. We established that delay discounting was steeper later in the session. In Experiment 2 participants again completed the delay discounting task twice, and we also tracked time perception across the session using the temporal bisection task. Once again, participants demonstrated steeper discounting during the second discounting task, but time perception did not differ significantly. Additionally, discounting rates were not correlated with subjective time perception. Changes in delay discounting across the session might be understood in terms of context or reference effects.