Ja. Simon et al., Discourse processing in women with fragile X syndrome: Evidence for a deficit establishing coherence, COGN NEUROP, 18(1), 2001, pp. 1-18
The language phenotype in individuals with fragile X syndrome (FXS) and its
relation to the molecular genetics of the disorder was investigated. Previ
ous research has focused on describing deviance in conversational speech, a
nd has not yet examined component discourse skills. The ability of women wi
th FXS to use coherence to select endings to humorous and straightforward p
assages was evaluated, and the relation of this with neuropsychological mea
sures of working memory, executive functions, and molecular measures of the
syndrome were also evaluated. Three groups of nonretarded women were exami
ned: (a) 14 women with FXS who carry the full mutation; (b) 25 women who ca
rry the premutation; and (c) 16 women without the fragile X mutation. The r
esults indicated that subjects with the full mutation showed a dramatic def
icit in selecting appropriate endings to jokes relative to stories, even th
ough the jokes were identical to the stories except for their endings. The
coherence deficit found in the jokes task for women with the full mutation
was found to correlate strongly with the X activation ratio, and to a neuro
psychological measure of working memory. The full mutation subjects' cohere
nce deficit is discussed in terms of the additional demand to hold informat
ion in memory and shift set.