Date of Award

Summer 7-23-2021

Degree Type


Degree Name

MS Experimental Psychology




Kelly M. Goedert, Ph.D.

Committee Member

Marianne Lloyd, Ph.D.

Committee Member

Michael Vigorito, Ph.D.


Time perception, Magnitude Interference, Perception, Internal Clock Account


Past research has found that errors made when acting on magnitude information is influenced by irrelevant magnitude information that is simultaneously present in the environment. This study investigated the processing stage during which the interference occurs. Each participant completed 80 test trials in stimulus (encoding stimulus) appeared on the computer screen for one of four lengths of time and then disappeared. After which, participants held down the computer spacebar for either the full or half the time that the encoding stimulus was on the screen. In both conditions, a second stimulus (reproduction stimulus) was displayed as the participants held down the spacebar. During each trial, one of the two stimuli was a gray square and the other was an Arabic numeral of low (1,2) or high (8,9) value. If participant reproductions were influenced by the numeral when it was presented during reproduction, this would suggest that the numeral magnitude influences the subjective time experienced in the moment. However, if the numeral stimulus only influenced participant time productions when it was presented as the encoding stimulus, it would suggest that the influence of the numeral happens in memory. In both the full and half-time conditions, we found a significant difference between low and high value stimulus numeral values only when the numeral stimulus was presented as the encoding stimulus. These findings provide evidence that the interference that has been observed in humans reproducing time durations occurs via interference in the memory component, rather than influencing the subjective perception of time progression.