Álvarez, C. J. 1 & Baquero, S. 2
1 Universidad de La Laguna, Tenerife, Spain
2 Universidad Nacional de Colombia
Individuals with Alzheimer disease (AD) tend to show impairments in several linguistic domains including both oral and written language skills. Phonological abilities have been traditionally found to remain relatively well preserved during the evolution of the disease with the exception of the severe stages. However, important handwriting difficulties have been reported, with differences depending on the concrete process under study (e.g. spelling and central processes vs. peripheral and motor stages). In the case of central-linguistic processes related to spelling and programming, the disparity among results as well as the lack of effects could be due to the methodologies used. In general, the analyses of errors has been virtually the exclusive measure. In this study, we employed on-line measures using digitilizing tablet, which allow to investigate the writing processes instead of just the outcome (i.e. analysis of errors), with the goal of studying possible subtle differences between normal participants and patients with AD. AD individuals were compared with a matched control group in a writing task. Letter durations and inter-letter intervals were measured. First, a difference between the evolution of the movement execution of the whole word was found between AD and normal participants. Second, the magnitude of the syllabic effect (previously obtained with normal adults) is different in the AD group in comparison with the control group. The results suggest that the phonological component of the graphemic buffer is damaged in individuals with AD, an outcome that it has not been previosly found using off-line measures.