Conscious and preconscious adaptation to rhythmic auditory stimuli: a magnetoencephalographic study of human brain responses
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This study was triggered by the experimental evidence that subjects required to tap in synchrony with a heard rhythm spontaneously time their tapping to variations in rhythm frequency even when these variations are so small that they are not consciously detectable. We performed a series of magnetoencephalographic (MEG) measurements, aimed at investigating whether the response of the auditory cortex discriminates randomly administered series of brief tones differing from each other only by their interstimulus intervals (ISI). Moreover, by combining psychophysical measurements, conscious and preconscious adjustments of tapping to rhythm variations were compared with brain cortical responses. The ISIs were varied by 2% or 20% from a “central” value of 500 ms. Subjects always consciously detected the 20% ISI changes and easily adjusted their tapping accordingly, whereas they never consciously detected the 2% ISI changes, even though they always correctly adjusted their tapping to them. Analysis of the auditory evoked fields (AEFs) showed that the intensity of the M100 component decreased with decreasing ISI both for 20% and 2% variations in a statistically significant manner, despite the fact that the 2% variation was not consciously perceived. The M100 behavior indicated that connections between auditory and motor cortexes may exist that are able to use the information on rhythm variations in the stimuli even when these are not consciously identified by the subject. The ability of the auditory cortex to discriminate different time characteristics of the incoming rhythmic stimuli is discussed in this paper in relation to the theories regarding the physiology of time perception and discrimination.
Key wordsRhythm perception Auditory evoked fields Auditory-motor synchronization Human
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- Fitzgibbons PJ, Pollatsek A, Thomas IB (1974) Detection of temporal gaps within and between perceptual tonal groups. Percept Psychophys 16:522–528Google Scholar
- Gallen C, Pantev C, Hampson S, Buchanan DS, Sobel D (1992) Reliability and validity of auditory neuromagnetic source localization using a large array biomagnetometer. In: Hoke M, Ernè SN, Okada YC, Romani GL (eds) Biomagnetism: clinical aspects. Excerpta Medica, Amsterdam, pp 171–175Google Scholar
- Kagerer F, Ilmberger J, Poppel E, Mates J, Radii T (1990) Auditory motor synchronization: timing in incremental and decremental rhythmic tapping. Act Nerv Super 32:145–146Google Scholar
- Melvill Jones G, Watt DGD (1971) Observations on the control of stepping and hopping movements in man. J Physiol (Lond) 219:709–727Google Scholar
- Miller RA, Thaut MH, Aunon JI (1994) Event related brain wave potentials in an auditory-motor synchronization task. In: Pratt RR, Spintge R (eds) Music medicine. MMB Music, St Louis, pp 76–84Google Scholar
- Pantev C, Hoke M, Luntkenhoner B, Fahrendorf G, Stober U (1990) Identification of sources of brain neuronal activity with high spatiotemporal resolution through combination of neuromagnetic source localization (NMSL) and magnetic resonance imaging (MRI). Electroencephalogr Clin Neurophysiol 75:173–184PubMedCrossRefGoogle Scholar
- Papanicolau AC, Banmann S (1990) Localization of auditory responses sources using MEG and MRI. Arch Neurol 47:33Google Scholar
- Povel DJ, Essen P (1985) Perception of temporal patterns. Music Percept 2:411–440Google Scholar
- Wearden JH, Penton-Voak IS (1995) Feeling the heat: body temperature and the rate of subjective time, revisited. Q J Exp Psychol 48:129–141Google Scholar