Some of the key findings of experimental psychology in the perception of time
Reference: Hearing in Time by Justin London
- Difference in stimuli mean difference in perception
Experimental results in discrimination and perception are different for sonic and visual stimili.
- Subjective Rhythmicization
We group a series of identical, isochronous stiumuli into groups of twos and threes, i.e. we hear duplets and triplets or a two-beat or three-beat “measures” even when there are no structural cues.
- Upper limit of subjective rhythmicization: about 1800ms
Above 1800ms successive sounds are not heard as continuous; therefore we no longer hear them in terms of a coordinated motion or movement.
- Connection between hearing/seeing rhythm and perceiving movement
Successive visual stimuli presented within a certain temporal range give the illusion of motion
- Shortest perceived interval: ~2ms
Usually measured as separation time required to discern that two tone onsents are present as opposed to one.
- Shortest ordered onset distinction: ~20ms (10 times the previous number!)
This is the shortest time necessary to discern which onset was first and which second.
- Longest interval that we can perceived/performed rhythmically: 5-6 seconds
- shortest perceptual duration regardless of sensory mode: around 130ms with %5-10 accuracy
Also shortest discernible interval between to brief sounds: (around 100ms)
Also the minimum time to allow for the cortical processing of musical elements (around 100ms).
Also the fastest possible vocal articulation of rapidly repeated syllables (around 120ms).
- Shortest musical beat/pulse: 200-250ms
At intervals less than this range, subjects begin to tap every other beat (i.e. they sub-divide)
But we can distinguish two onsets as two when they are 100ms apart! what’s up? Hearing a “beat” requires at least the potential for subdivision.
- Shortest anti-phrase repeatable musical beat: around ~450ms
Stimulus is a repeated tone, subject is asked to tap/clap in between the notes
- The “Indifference Interval”: 600-700s
This is the tempo at which a beat is subjectively neither “too fast” or “too slow”
Also the time interval below which subjects overestimate, and above which subjects underestimate the elapsed duration
Also the “spontaneous temp” or “natural pace”: the tempo at which subjects tap a finger with no other instructions (there’s great variation, but the mean is ~600ms)
Spontaneous tempo varies with age: younger subjects (4-6 years) prefer ~400ms; suggests that “spontaneous tempo” is kinematically rooted (i.e. smaller body, faster tempo)
- The “Just Noticeable Difference”: 200-250ms
A basic psychological measure of perceptual acuity: the shortest perceivable difference in duration between two complex stimuli; e.g. Smallest perceivable difference of duration between two six-tone sequences over a wide range of inter-onset-intervals (from 100 to 1000ms)
The JND is proportional to the total duration of the stimuli.
- Subject Rhythmic Organization
Differing contexts or modes of attention affect perception of duration/interval. For example, when performers are directed to shift their attention to different levels within the metrical hierarchy in a series of performances of the same passage, focusing on the eighth notes versus quarters versus half notes causes systematic shifts in tempo: Counting at higher levels leads to faster performances.
London, J. (2004). Hearing in time: Psychological aspects of musical meter. New York: Oxford University Press.
Desain, P., & Windsor, L. (2000). Rhythm perception and production. Lisse ; Exton (PA): Swets & Zeitlinger Publishers.