The Journal of Neuroscience, May 14, 2008, 28(20):5281-5289; doi:10.1523/JNEUROSCI.0565-08.2008
Previous Article | Next Article 
Behavioral/Systems/Cognitive
Spoken Word Memory Traces within the Human Auditory Cortex Revealed by Repetition Priming and Functional Magnetic Resonance Imaging
Pierre Gagnepain,
Gael Chételat,
Brigitte Landeau,
Jacques Dayan,
Francis Eustache, and
Karine Lebreton
Inserm-Ecole Pratique des Hautes Etudes-Université de Caen/Basse-Normandie, Unité 923, Groupement d'Intérêt Public Cyceron, Centre Hospitalier Universitaire Côte de Nacre, F-14074 Caen, France
Correspondence should be addressed to Karine Lebreton, Groupement d'Intérêt Public Cyceron, Inserm-Ecole Pratique des Hautes Etudes-Université de Caen/Basse Normandie, Unité U923, Boulevard Henri Becquerel, BP 5229, F-14074 Caen Cedex, France. Email: lebreton{at}cyceron.fr
Previous neuroimaging studies in the visual domain have shown that neurons along the perceptual processing pathway retain the physical properties of written words, faces, and objects. The aim of this study was to reveal the existence of similar neuronal properties within the human auditory cortex. Brain activity was measured using functional magnetic resonance imaging during a repetition priming paradigm, with words and pseudowords heard in an acoustically degraded format. Both the amplitude and peak latency of the hemodynamic response (HR) were assessed to determine the nature of the neuronal signature of spoken word priming. A statistically significant stimulus type by repetition interaction was found in various bilateral auditory cortical areas, demonstrating either HR suppression and enhancement for repeated spoken words and pseudowords, respectively, or word-specific repetition suppression without any significant effects for pseudowords. Repetition latency shift only occurred with word-specific repetition suppression in the right middle/posterior superior temporal sulcus. In this region, both repetition suppression and latency shift were related to behavioral priming. Our findings highlight for the first time the existence of long-term spoken word memory traces within the human auditory cortex. The timescale of auditory information integration and the neuronal mechanisms underlying priming both appear to differ according to the level of representations coded by neurons. Repetition may "sharpen" word-nonspecific representations coding short temporal variations, whereas a complex interaction between the activation strength and temporal integration of neuronal activity may occur in neuronal populations coding word-specific representations within longer temporal windows.
Key words: repetition priming; spoken word; auditory cortex; fMRI; repetition suppression; repetition enhancement
Received Feb. 7, 2008;
revised March 12, 2008;
accepted March 23, 2008.
Correspondence should be addressed to Karine Lebreton, Groupement d'Intérêt Public Cyceron, Inserm-Ecole Pratique des Hautes Etudes-Université de Caen/Basse Normandie, Unité U923, Boulevard Henri Becquerel, BP 5229, F-14074 Caen Cedex, France. Email: lebreton{at}cyceron.fr
This article has been cited by other articles:

|
 |

|
 |
 
M. H. Davis and M. G. Gaskell
A complementary systems account of word learning: neural and behavioural evidence
Phil Trans R Soc B,
December 27, 2009;
364(1536):
3773 - 3800.
[Abstract]
[Full Text]
[PDF]
|
 |
|