Temporal productions in a variable environment: timing starts from stimulus identification rather than onset

Area of Science:

• Cognitive Psychology
• Neuroscience
• Human Timing Perception

Background:

• Accurate time perception is crucial for daily activities and skilled performance.
• Previous research on interval timing has explored various factors influencing accuracy, including attention and sensory processing.

Purpose of the Study:

• To investigate how temporal and event uncertainty influence human interval timing production.
• To determine whether timing initiation is linked to stimulus perception or identification.

Main Methods:

• Participants produced target durations (500-1250 ms) by terminating an initiated interval or maintaining a key press.
• Temporal uncertainty was manipulated using a variable foreperiod.
• Event uncertainty was manipulated by varying required durations (variable vs. constant blocks).

Main Results:

• When participants initiated and terminated intervals, environmental uncertainty did not significantly affect timing productions.
• When participants only terminated intervals, productions were longer and less precise under uncertainty.
• Uncertainty effects were more pronounced when participants only terminated the interval, suggesting a role for stimulus identification.

Conclusions:

• Environmental uncertainty impacts interval timing, particularly when participants do not initiate the timed interval.
• Findings suggest that the initiation of timing may depend on stimulus identification rather than initial sensory registration.
• Event uncertainty might postpone the onset of timing processes.