Temporal preparation in adults with autistic spectrum disorder: The variable foreperiod effect.
Adults with autism miss hidden timing cues, so they respond late or not at all when the pace shifts.
01Research in Context
What this study did
Girardi et al. (2021) asked adults with and without autism to press a key when a circle appeared.
The circle could show up soon or late, and the timing changed from trial to trial.
The team measured how fast people pressed and how often they forgot to press at all.
What they found
Adults without autism pressed faster when the circle came later than the last trial.
Adults with autism did not speed up; they also missed more late circles.
Their brains seemed to ignore the hidden timing cue that usually helps us get ready.
How this fits with other research
Schunke et al. (2016) saw the same slow, rigid style in a copy-cat task, so the trouble is not just about time.
Lim et al. (2016) and Boudreau et al. (2015) also found weaker brain responses to simple visual changes, lining up with the missed timing cue.
Chien et al. (2018) looked at teens and young adults and found faster, not slower, brain waves. This sounds opposite, but they studied a different wave (P3a) that flags surprise, not preparation, so the two results can coexist.
Why it matters
Your client may look inattentive when tasks speed up or slow down, but the real issue is poor internal timing. Give warnings that are visual, spoken, and timed the same way each trial. Avoid sudden shifts in schedule; if you must change, re-teach the new pace like a new skill.
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Join Free →Keep the inter-trial interval the same for at least ten trials; if you change it, give a clear countdown cue before the first new-speed trial.
02At a glance
03Original abstract
Research suggested the possibility that temporal cognition may be different in autistic spectrum disorder (ASD). Although there are some empirical studies examining timing ability in these individuals, to our knowledge, no one directly assessed the ability to predict when an event will occur. Here, we report a study on implicit temporal preparation in individuals with ASD as indexed by the variable foreperiod (FP) effect. We compared a group of adult ASD participants to a group of typically-developed (TD) controls, for their respective abilities to utilize implicit temporal information in a simple detection task with three different preparatory intervals (FP, short, middle and long). Participants were given a warning tone to signal an imminent stimulus, and asked to press a key as quickly as they could upon detection of the stimulus. Both groups were able to use implicit temporal information, as revealed by both the variable-FP effect (i.e., faster response for targets appearing after a long FP) and asymmetric sequential effects (i.e., slower response in short-FP trials following a previous long-FP trial). The TD group exhibited a faster response in a long-FP trial that was preceded by short-FP one, whereas the ASD group did not, as reflected in their higher percentage of response omissions for a target that appeared later than in the previous trial. The reduced ability of ASD participants to modulate their responses under these conditions might reflect a difficulty in time-based monitoring of stimulus occurrence. LAY SUMMARY: Time-processing may be different in autistic spectrum disorder (ASD). This study addressed the ability to anticipate a relevant stimulus's onset according to predictable interstimulus intervals comparing adults with ASD and typically developed controls. We found that ASD participants did not benefit from temporal preparation when stimulus appeared later than previously attended. This suggests a reduced ability in detecting implicit temporal regularities between events.
Autism research : official journal of the International Society for Autism Research, 2021 · doi:10.1002/aur.2573