Visuo-spatial and Lexical Processing in Neglect Dyslexia and Older Age

Visuo-spatial and Lexical Processing in Neglect Dyslexia and Older Age

People involved

Christiane Weinzierl
Prisca Stenneken

 

In cooperation with:

Georg Kerkhoff
Lucia van Eimeren
Ingo Keller
Arthur M. Jacobs

 

Project Summary:

Spatial neglect may involve neglect dyslexia resulting in a failure to identify words or parts of words in the contralesional hemispace. The present study explored a well-documented dissociation in neglect dyslexics' word processing, i.e. impaired reading aloud in the presence of good lexical decision performance for the same stimuli. To investigate whether this dissociation is also reflected in the visuo-spatial characteristics of word processing, a well-established paradigm of word processing in normal readers (technique of variable viewing positions, was combined with a word naming and a lexical decision task. The word stimuli varied orthogonally along the two linguistic dimensions of word frequency (lexical manipulation) and syllable number (sublexical manipulation). We expected the dissociation in neglect dyslexia to be reflected in task-specific effects in naming and lexical decision. This was partly confirmed by an interaction of task demands with viewing-position-specific results. Interestingly these results pointed to a task-dependency in word processing not only in neglect patients but also in normal readers, when equal error rates were experimentally obtained between control and neglect participants. Together with the finding of a task-specific effect of syllable number in the neglect group, the present results suggest that task demands modulate the degree of neglect dyslexia from early stages of visual word processing. 

Additional ongoing error analyses of neglect patients and older adults are expected to clarify the following questions:
Do neglect dyslexic persons have a different distribution of error types than normal readers?
Which letter positions within in words are affected in reading errors of neglect dyslexic persons and in older age? Is there an influence of linguistic aspects?