ausblenden:
Schlagwörter:
lexical learning; magnetoencephalography; picture naming; categorization; phonology;
semantics
Zusammenfassung:
Ten healthy adults encountered pictures of unfamiliar archaic tools and successfully learned
either their name, verbal definition of their usage, or both. Neural representation of the newly acquired
information was probed with magnetoencephalography in an overt picture-naming task before and after
learning, and in two categorization tasks after learning. Within 400 ms, activation proceeded from
occipital through parietal to left temporal cortex, inferior frontal cortex (naming) and right temporal
cortex (categorization). Comparison of naming of newly learned versus familiar pictures indicated that
acquisition and maintenance of word forms are supported by the same neural network. Explicit access
to newly learned phonology when such information was known strongly enhanced left temporal activation.
By contrast, access to newly learned semantics had no comparable, direct neural effects. Both
the behavioral learning pattern and neurophysiological results point to fundamentally different implementation
of and access to phonological versus semantic features in processing pictured objects.
