Temporal predictions shape somatosensory perception

Although intensity expectations have been thoroughly studied in relation to pain, there has been a notable lack of investigation into temporal expectations. One important temporal pain effect, the so-called dread effect, suggests that future pain becomes more aversive with increasing delay. Here we investigated temporal expectations including the dread effect by presenting probabilistically cued painful heat and non-painful cold stimuli after different delay periods. Actual stimulus latency had no effect on perceived intensity in both non-painful cold and painful heat conditions. However, our data clearly show that the expectation of longer delays amplified somatosensory perception, indicating that the dread effect is related to expected and not to experienced delay. Electroencephalography data show that temporal expectations modulate alpha/beta activity during cue presentation, but not during stimulation. Actual stimulus timing is represented in alpha-to-beta frequencies during heat and cold stimulation.