beni ingilizcesiyle etkileyene msnimi veriyorum

throughout the field of neuropsychology, evidence for complex implicit
competence has been documented in patients with neurological damage and
limited linguistic, attentional, or mnemonic performance. such results suggest that systems are activated and carrying out their functions even though
this information is no longer available for conscious planning and problem
solving. one example of this sort of competence in the face of impaired
behavior is lexical and semantic priming in neurological populations. results
of this sort have been widely reported but their neurological implications
and relation to psycholinguistic models of processing have not been made
clear.
the goal of this symposium is to examine the locus of both preserved and
disturbed facilitation from the level of form represented by repetition priming
to the level of conceptual knowledge represented by pictures. at the periphery, dr. swick’s studies of patients with left and right temporal parietal lesions demonstrate intact repetition priming for words, but an impairment in
repetition priming of nonwords in left lesioned patients. prior work has
shown that both word and nonword repetition priming were intact in patients
with frontal lobe damage. she hypothesizes that this may be related to a
defective phonological store in the left temporal parietal patients which is
crucial to establishing a stable representation of the nonword stimuli. drs.
baynes and dronkers have examined the hemispheric organization and integration of lexical-semantic and conceptual knowledge by studying facilitation of words and pictures in normal controls, focal lesion patients and splitbrain subjects. facilitation effects indicate that both hemispheres support a
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semantic network with preferential processing of lexical information in the
left hemisphere and conceptual information in the right hemisphere. these
results are consistent with the idea that lexemes and concepts are represented
by dual codes, a verbal based code and an image based code (paivio, 1991).
this idea finds further support in the erp results of the third paper in this
symposium presented by dr. swaab. efficient integration of lexical-semantic
and conceptual information requires an intact corpus callosum. additionally,
in this study, the role of the right hemisphere in the processing of associative
and purely semantic relations between words was examined in patients that
have a focal lesion in the right hemisphere. results indicate that sensitivity
to semantic relations is disrupted in right hemisphere lesioned patients, which
indicates that the right hemisphere may be involved in processing more distant semantic relations between words, or coarse semantic coding (beeman
et al., 1994). finally, dr. ober has exhaustively studied the semantic and
associative priming of patients with alzheimer’s dementia (ad) under a variety of conditions to better characterize semantic memory in ad. she has
concluded that the implicit knowledge of semantic relations is indeed intact
in mild to moderate alzheimer’s disease and that task variables have a powerful influence on the performance of patients and controls. the robustness
of semantic knowledge in this population argues for a distributed representation of conceptual knowledge that is maintained well into the dementing
process.
how these results relate to models of psycholinguistic processing, including associative networks such as the hal model (burgess & lund, 1997),
and more traditional spreading activation models (e.g., anderson, 1983 ) will
be discussed by dr. debra long, a cognitive psychologist whose own work
in text comprehension and memory has looked at the contribution of individual differences to successful reading performance. consideration will be
given to the degree to which modular processes and distributed systems can
be compatibly represented. she will integrate the common threads from these
papers and suggest directions for (bitti)