Perceptual biases for rhythm: The Mismatch Negativity latency indexes the privileged status of binary vs non-binary interval ratios

Clin Neurophysiol. 2007 Dec;118(12):2709-15. doi: 10.1016/j.clinph.2007.08.019. Epub 2007 Oct 18.


Objective: Rhythm perception appears to be non-linear as human subjects are better at discriminating, categorizing and reproducing rhythms containing binary vs non-binary (e.a. 1:2 vs 1:3) as well as metrical vs non-metrical (e.a. 1:2 vs 1:2.5) interval ratios. This study examined the representation of binary and non-binary interval ratios within the sensory memory, thus yielding a truly sensory, pre-motor, attention-independent neural representation of rhythmical intervals.

Methods: Five interval ratios, one binary, flanked by four non-binary ones, were compared on the basis of the MMN they evoked when contrasted against a common standard interval.

Results: For all five intervals, the larger the contrast was, the larger the MMN amplitude was. The binary interval evoked a significantly much shorter (by at least 23 ms) MMN latency than the other intervals, whereas no latency difference was observed between the four non-binary intervals.

Conclusions: These results show that the privileged perceptual status of binary rhythmical intervals is already present in the sensory representations found in echoic memory at an early, automatic, pre-perceptual and pre-motor level.

Significance: MMN latency can be used to study rhythm perception at a truly sensory level, without any contribution from the motor system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Adult
  • Auditory Perception / physiology*
  • Bias
  • Brain Mapping / methods
  • Cerebral Cortex / physiology
  • Electroencephalography
  • Evoked Potentials / physiology*
  • Female
  • Humans
  • Male
  • Memory / physiology
  • Music
  • Neuropsychological Tests
  • Periodicity*
  • Pitch Discrimination / physiology
  • Reaction Time / physiology*
  • Recognition, Psychology / physiology
  • Signal Processing, Computer-Assisted
  • Time Perception / physiology*