Fig 1.
Scalar Expectancy Theory (SET) model of time perception. Adapted from Church, 1984.
To summarize: a pacemaker releases isochronous signals, which are collected by an accumulator function when attention is directed to time passing. The accumulator values can be compared to a reference memory for accumulator values from a previous exposure to the time interval, to determine whether the currently timed interval has lasted a similar duration (comparator function). If the difference between the value from reference memory and the current accumulator value is below a given threshold, the decision is made that the time interval is equal to the memory for a standard. The model was originally developed to explain animal behavior in a fixed interval/peak interval paradigm, but has been applied to human timing as well.
Fig 2.
Experiment 1: Percent of “longer” responses at each stimulus duration for each stimulus type.
Participants were divided on the basis of EMCP scores (see Methods). (a) Responses to pictures of Black Men and White Men in participants that did not score high on this measure. (b) Responses in participants that did score high on this measure. The dotted arrow in (b) signifies a shift of responses to Black Men in the High EMCP participants.
Fig 3.
Experiment 1: PSE difference scores for each stimulus type.
Data for each participant, for each stimulus type, were fit with a sigmoid curve and a resulting point of subjective equality (PSE) was calculated (see Methods). PSE Difference Score = (Object PSE–White Man PSE) OR (Object PSE—Black Man PSE). X axis represents different subject groups (EMCP score) and Y axis represents PSE difference score.
Fig 4.
Experiment 2: Percent of “longer” responses at each stimulus duration for each stimulus type.
Participants experienced either a White experimenter or a Black experimenter (see Methods). (a) Responses to pictures of Black Men and White Men in participants that participated with a White experimenter. (b) shows responses in participants that participated with a Black experimenter. The dotted arrow in (b) signifies a shift of responses to Black Men in the participants that participated with a Black experimenter.
Fig 5.
Experiment 2: PSE difference scores for each stimulus type.
Data for each participant, for each stimulus type, were fit with a sigmoid curve and a resulting point of subjective equality (PSE) was calculated (see Methods). PSE Difference Score = (Object PSE–White Man PSE) OR (Object PSE—Black Man PSE). X axis represents different subject groups (experimenter group) and Y axis represents PSE difference score.