Speeding up and (…relatively…) slowing down an internal clock in humans

Area of Science:

• Psychology
• Cognitive Science
• Neuroscience

Background:

• The internal clock model proposes a pacemaker mechanism for time perception.
• Previous research suggests external stimuli can modulate this internal clock.

Purpose of the Study:

• To investigate if click-trains can alter the subjective duration of stimuli.
• To provide evidence for the relative speeding up and slowing down of the internal clock's pacemaker.

Main Methods:

• Experiment 1: Used a pair comparison procedure with tones of equal duration, preceded or not by click-trains.
• Experiment 2: Employed a bisection method using standard tones (200 and 800 ms) and comparison stimuli, with click-train manipulations.

Main Results:

• Experiment 1 showed that click-trains shifted duration judgments in both directions, supporting pacemaker modulation.
• Experiment 2's psychophysical functions shifted oppositely based on click-train placement, indicating flexible pacemaker control.

Conclusions:

• Click-trains effectively manipulate subjective time perception by altering the internal clock's pacemaker speed.
• These findings support the hypothesized internal clock model and its pacemaker mechanism.