Double standards: Memory loading in temporal reference memory

Three experiments compared human performance on temporal generalization tasks with either one or two different, and distinct, standard durations encoded. In the first two experiments participants received presentations of two different standards at the beginning of each trial block and were instructed to encode either one or both of them. When instructed to encode one standard they then had to judge whether each of a number of comparison stimuli was or was not that standard. When instructed to encode both they were then tested using just one of the standards but the participants were unaware, at the time of encoding, which standard would later be used as a reference. No marked effect of the number of temporal standards encoded was found. In Experiment 3 participants received either one or two temporal standards and had to use both when two were presented. This manipulation produced flatter generalization gradients when two standards were encoded than when just one was, and modelling attributed this difference mainly to an increase in reference memory variability in the double-standard case. This suggests that the variability of representation of durations in temporal reference memory can be systematically increased by increasing temporal reference memory load.     

Active and passive distraction using a head-mounted display helmet: effects on cold pressor pain in children.

OBJECTIVE: The current study tested the effectiveness of interactive versus passive distraction that was delivered via a virtual reality type head-mounted display helmet for children experiencing cold pressor pain. DESIGN: Forty children, aged 5 to 13 years, underwent 1 or 2 baseline cold pressor trials followed by interactive distraction and passive distraction trials in counterbalanced order. MAIN OUTCOME MEASURES: Pain threshold and pain tolerance. RESULTS: Children who experienced either passive or interactive distraction demonstrated significant improvements in both pain tolerance and pain threshold relative to their baseline scores. In contrast, children who underwent a second cold pressor trial without distraction showed no significant improvements in pain tolerance or threshold. CONCLUSION: Although both distraction conditions were effective, the interactive distraction condition was significantly more effective. Implications for the treatment of children's distress during painful medical procedures are discussed.