These accounts embody three critical assumptions:
- semantic representations are amodal;
- the mapping between surface form and meaning varies for different modalities; and
- the representations are dynamic.
The influence of these three factors was revealed in data collected over a 4-year longitudinal period in two patients with semantic dementia.
Semantic assessment revealed a parallel decline in verbal and nonverbal aspects of conceptual knowledge, reflecting a gradual degradation of a single amodal semantic system. As expected, when the patients' semantic impairment was mild, they presented with profound anomia but relatively preserved object use. Over time, performance on all semantic tasks including object use declined. High item-by-item consistency across these tasks was observed in all testing sessions. The impact of dynamic semantic representations was revealed by a striking clinical finding.
Although unable to name many of the objects in isolation, their performance was significantly facilitated if they were asked to name while they demonstrated the use of each object. These results are discussed in the context of contemporary models of semantic memory.
Source: Semantic memory is an amodal, dynamic system: Evidence from the interaction of naming and object use in semantic dementia, Michela Coccia, Marco Bartolini, Simona Luzzi, Leandro Provinciali (Ospedale Umberto I Ancona Italy), Matthew A. Lambon Ralph (University of Manchester Manchester UK), Cognitive Neuropsychology, Volume 21 (5), July 2004, pp. 513-527.
- как работает организация/использование "контекстов"?
- как устроена кросс-модальность памяти?
- как угасает распознание метафор/юмора при деменции?