21世紀COE心の働きの総合的研究教育拠点

心の抑制機能に関する講演会

　この度，英国マンチェスター大学のMatthew A. Lambon Ralph先生とケンブリッジMRC Cognition & Brain Sciences UnitのKaralyn Patterson先生が来日されます．この機会を利用してお二人にご講演いただくことにいたしました．直前のご案内となってしまいましたが，多数の方々のご参加をお待ちいたしております．

日時：2005年12月1日（木）14:00-16:00

場所：京都大学百周年時計台記念館　２階　会議室�W

（建物の場所は以下のWebpgeをご参照ください）
https://www.kyoto-u.ac.jp/access/kmap/map6r_y.htm

講演者，講演題目および講演要旨：

講演者
Matthew A Lambon Ralph, PhD
Professor of Cognitive Neuroscience, University of Manchester, UK

題目
Semantic impairment in semantic dementia and stroke aphasia: loss of knowledge versus loss of inhibition/control.

要旨：
Deficits in semantic cognition occur in a number of neurological diseases. Some of the best known and most striking types of semantic impairment are found in patients with semantic dementia (SD) and stroke (CVA resulting, for example, in global, Wernickes or transcortical sensory aphasia). Investigations of the semantic impairment in each disease have tended to be conducted by different researchers, using different assessments and are reported in different literatures. There are very few direct comparisons of these two diseases and so it is unclear how similar/dissimilar the semantic impairments are. In some of our recent work we have completed direct comparisons of these three diseases using the same battery of tasks. These were selected to assess both verbal and nonverbal comprehension as well as expressive tasks that are directly reliant upon the integrity of semantic representations (e.g., naming). The comparison is also a neurologically intriguing one given that SD is associated with bilateral anterior temporal lobe damage, whereas semantic impairments in CVA typically involve the left temporo-parietal junction or left prefrontal cortex. The contrast between SD and CVA highlighted a degradation of core knowledge in SD but a deficit of semantic control/inhibition in CVA. These results are considered in terms of implemented PDP connectionist models of conceptual knowledge. The differing nature of the semantic deficits suggests that SD reflects damage to core semantic knowledge while semantic impairment in CVA reflects disruption to the control/inhibitory mechanisms that are required for semantic knowledge to be shaped for task/context appropriate behaviour.

講演者
Karalyn Patterson, PhD, FMedSci
Senior Scientist, Medical Research Council, Cognition & Brain Sciences Unit, Cambridge UK

題目
The impact of semantic impairment on 'non-semantic' tasks: the role of semantic memory in inhibiting the influence of typicality.

要旨：
Much of human cognitive activity consists either of recognition (of familiar words, objects, people, etc.) or of production (of speech, object use, etc). In both of these broad categories, there is often a degree of conflict between two sources of information relevant to the outcome of the recognition or production process. One concerns the persons knowledge of features specific to the object or word to be recognised or produced; the other concerns his or her knowledge of features that are typical of the general class of thing being processed. This conflict is particularly prominent for OEatypical? items within some domain, whose individual features are discrepant from the majority of their neighbours. For example, if a person is judging whether a particular animal is a bird, and the bird in question is a penguin (which does not fly), this is a source of conflict. Likewise, if a person is asked to read aloud a word written in Kanji, and the word in question has an atypical pronunciation of one or more of its component characters, this is also a source of conflict. Our recent research on patients with semantic dementia (a neurodegenerative condition resulting in fairly selective deterioration of conceptual knowledge) suggests that item-specific semantic information is crucial in resolving this kind of conflict, whether in recognition or production. As specific semantic knowledge deteriorates, the patients can no longer counteract or inhibit the influence of domain-typical knowledge.

以上です．

企画・連絡先：齊藤　智（京都大学大学院教育学研究科）