ABSTRACT
In this paper we explore the influences of normal ageing and verb transitivity on sentence production. The underlying aim is to provide a foundation for further research on sentence production in Alzheimer's disease (AD). We used a computer-based written sentence production task, designed to elicit intransitive, monotransitive and ditransitive sentences. Data was collected using keystroke logging, a technique to capture the entire typing process. Data of ninety healthy elderly was analysed focusing on the following writing process variables: time on task, production time and pause times. Results show that age influences time on task, pause time before sentences and within words. Verb transitivity influences time on task, production time and pause time between words. For pause time before sentences and between words, an interaction effect between age and verb transitivity was found as well. These results indicate that a follow-up study with AD patients should not attribute a slowdown in one of these variables to the disease in its entirety but should instead be compared with the slowdown in age-matched healthy peers.
ABSTRACT
In this article, we explore if the observation of writing behavior can assist in the screening and follow-up of mild cognitive impairment (MCI) and mild dementia due to Alzheimer's disease (AD). To this end, we examined the extent to which overall writing process measures and pausing behavior during writing differed between 15 cognitively impaired patients and 15 age- and gender-matched healthy controls. Participants completed two typed picture description tasks that were registered with Inputlog, a keystroke logging program that captures keyboard activity during text production. The following variables were analyzed with mixed-effects models: time on task; number of characters, pauses and Pause-bursts per minute; proportion of pause time; duration of Pause-bursts; and pause time between words. For pause time between words, also the effect of pauses preceding specific word categories was analyzed. Results showed a main effect of group on all variables. In addition, for pause time between words a main effect of part-of-speech was found as well. Results indicate that writing process analysis can possibly serve as a supplementary tool for the screening and follow-up of AD.
ABSTRACT
Researchers often decide on the number of trials included in an experiment without adhering to an empirical method or framework. This might compromise generalizability and unnecessarily increase participant burden. In this article we want to put forward generalizability theory as a guide for task reduction. We will use a sentence production task to demonstrate how a generalizability and a decision study can help researchers to estimate the minimum number of trials and of items per trial that are necessary to generalize over trials. We obtained writing process data for 116 participants. Each of them completed a sentence production task that had 40 trials. Pause times between and within all words, target nouns and target verbs were logged with the keystroke logging tool ScriptLog. Results demonstrate that generalizability theory can serve as an empirical framework to ensure generalizable measurements on the one hand, and reduce participant burden to a minimum on the other. This finding is particularly valuable for studies with vulnerable target groups, such as participants suffering from aphasia, dyslexia or Alzheimer's disease.
