* LAB	* Acknowledgements
* Collaborators	* Current Projects
* Abstracts and Papers	* Events

Current Projects

Dr. Susan Kemper: Roy A. Roberts Distinguished Professor of Psychology and Gerontology

• Doing Two Things at Once
• The Nun Study
• Eye Tracking

Doing Two Things at Once

A series of studies have been completed that use innovative new techniques to investigate the effects of aging on language production by using "on-line" experimental tasks to directly manipulated working memory demands of sentence production tasks. Correlational techniques are used to examine how individual differences in cognitive tests of verbal ability, processing speed, working memory, and inhibition affect older adults' speech production.

Series 1 analyzed language samples to assess the effects on concurrent processing demands on speech fluency, syntactic complexity, and semantic content. A baseline language sample was compared to language samples collected while participants were concurrently walking, tapping their index fingers, tapping four fingers in a complex pattern, listening to concurrent speech, and listening to auditory babble. These concurrent tasks have previously been shown to affect performance on working memory tasks, hence, they are predicted to compete for working memory and affect speech production. Walking and tapping rates were examined in baseline and concurrent speaking conditions. For results, please see our paper "The costs of doing two things at once for younger and older adults."

For a summary of this research on "doing two things at once," see a recent publication.

click here for the abstract

click here for a pdf copy of the paper

In a follow-up study, we increased the difficulty of the walking task and again examined language performance. Our results may be found in our paper "Different effects of dual task demands on the speech of young and older adults."

click here for the abstract

A new series of studies is currently being initiated. There will be a simple motor task that can be synchronized to the speaking task. Older and young adults will engage in a variety of speaking tasks that vary in difficulty - e.g., reciting the alphabet or giving a spontaneous speech, while engaged in the motor task, tracking a revolving target, accuracy on the motor task will be used to measure the "costs" of speaking from moment-to-moment, giving us a detailed look at how individuals manage to do 2 things at once.

A related study compared healthy older adults and older adults who have previously had strokes.

click here for the abstract
click here for link to PDF

Series 2 used a sentence production task that controls the choice of lexical items and examines the latency to generate a sentence using a specified set of lexical items and that examines the complexity of the generated sentence. Three experiments were conducted: (2a) To examine sentence initiation times and sentence complexity as a function of the size of the set of specified lexical items. (2b) To examine sentence initiation times and sentence complexity for sentences generated from single verbs or for sentences generated from multiple verbs. (2c) To examine sentence initiation times and sentence complexity for sentences generated to complete simple and complex sentence frames using a specified inventory of lexical items.

The Nun Study

Additional work in collaboration with Dr. David Snowdon at the University of Kentucky involves the application of language sample analysis to autobiographical materials collected as part of the Nun Study. This longitudinal study seeks to identify risk factors for the development of Alzheimer's disease. Our initial findings suggest that low levels of linguistic ability in young adulthood, as measured by grammatical complexity and propositional density, are predictive of the development of dementia in late adulthood. Other analyses examined how change in linguistic ability may foreshadow the onset of dementia in late life. More information about the Nun Study can be found by visiting their website at http://web1.mccs.uky.edu/nunnet/.

For a humorous look at this research, here's a page from The New Yorker.

 

Eye Tracking

In collaboration with Dr. Joan McDowd at KUMC, I am now using eye tracking to examine reading under distracting conditions. We are testing the Inhibition Deficit Hypothesis by examining eye fixation patterns of young and older adults as they read sentences (later we'll try paragraphs) with interpolated distracting words. IDH claims that young adults can easily ignore such distracters but older adults are unable to ignore them and attempt to integrate the distracters with teh sentence, taking and impairing comprehension. If so, there should be clear differences in the eye fixation patterns of young and older adults.

Our findings suggest that young and older adults have similar fixation patterns. We find little support for the Inhibition Deficit Hypothesis. Other factors such as linguistic processing and visual attention pose problems for older adults reading under distraction.

click here for a pdf copy of the paper