Cross-linguistic Perception of Voiceless Fricatives - A Magnetoencephalography-study
Silvia Lipski
University Stuttgart
This study investigates whether an effect of linguistic experience can be seen in the response of the human auditory cortex when perceiving voiceless fricatives.
With the method of magnetoencephalography (MEG) the response of neurons to auditory events can be recorded with precise temporal resolution (see Naatanen 1992 for a thorough introduction). It is possible to track automatic and preconscious processing of percepts and the results of several studies suggest that the native language exerts influence even at this level of neural processing (see Naatanen (2001) for a review).
As in most MEG-studies, this study employs the oddball-paradigm: Standard stimuli are repetitively presented while deviant stimuli are interspersed at infrequent times. The repeating standard stimuli creates a sensory representation and when a deviant is presented, the mismatch between this sensory percept and the new stimulus causes the neurons to fire more strongly. The more clearly a mismatch is perceived, the stronger the neural response will be.
This study tested three fricative-contrasts for a group of 12 Polish and 12 German listeners. The contrasts are of different phonological status for the two groups in order to assess a possible influence of the native phonological system on the behavior of the auditory cortex.
The fricative-contrasts that have been tested are:
- German/Polish phonemic contrast between the voiceless alveolar and postalveolar fricatives
- Polish phonemic contrast between the voiceless postalveolar and palato-alveolar fricatives
- German allophonic contrast between the voiceless palatal and velar fricative.
References:
Naatanen, R. 1992. Attention and Brain Function. Lawrence Erlbaum: Hillsdale, NJ.
Naatanen, R. 2001. The perception of speech sounds by the human brain as reflected by the mismatch negativity MMN and its magnetic equivalent MMNm. Psychophysiology, 38,1--21.