▼ Communication impairments are a frustration for persons with Alzheimer’s disease (AD) and they are directly related to problem behaviors, which are predictors of caregiver burden (Savundranayagam, Hummert, and Montgomery, 2005). Linguistic ability declines as AD progresses, but nonverbal communication such as pointing, touching and gesturing is reported to be effective (Bayles and Kaszniak, 1987; Mace, 2005; Mace and Rabins, 1991). Pantomime ability in AD has been studied, primarily, to test for apraxia or to compare to linguistic decline. The purpose of this study was to assess the potential of pantomime as a communication tool. Sixteen persons diagnosed with Alzheimer’s-type dementia and 14 diagnosed with dementia were administered a Pantomime Production Assessment (PPA) and a Pantomime Comprehension Assessment (PCA). Pantomime production is demonstrating the use of an object (i.e., a spoon), and pantomime comprehension is identifying an object or action demonstrated by another person. Pantomime scores were compared between three levels of cognitive impairment. There were not significant differences between the mild (M = .97, SD =. 03) and moderate (M = .90, SD =. 08) groups on the PCA, but both were significantly better than the severe (M = .60, SD =. 18) group. The same pattern occurred with PPA scores. PCA scores were significantly higher when participants were given a pictorial response format compared to a verbal response format. These findings suggest pantomime ability remains relatively intact in the mild and moderate stages of AD/dementia, and those in the severe stages maintained some pantomime ability. These findings emphasize the importance of modifying tasks to be appropriate to level of cognitive functioning. Participants were also administered the clock drawing task, a confrontation naming test, the Peabody Picture Vocabulary Test III, and a praxis test to find out which variables are predictors of pantomime performance. The confrontation naming score was the best predictor of PCA and PPA scores. It is also of interest that participants were able to recognize pantomimes for 83% of the items they could not name, suggesting that pantomime can augment communication. Advisors/Committee Members: Sterns, Harvey L.

▼ This study examined cross-task compatibility and aging on dual-task and task-switching performance. Koch and Prinz’ (2002) work on cross-task compatibility suggests that response code activation improves performance when dual tasks are performed. That is, switching from a first task to a second task has a greater performance benefit when both tasks share the same specific response code. The role of aging on cross-task compatibility effects was examined in this dissertation. Three specific hypotheses were examined. The first hypothesis was that the method used in Experiment 1 would replicate the cross-task compatibility effects found in Koch and Prinz (2002). The second hypothesis was that older adults would demonstrate a comparable, if not better, benefit from cross-task compatibility as younger adults (both Experiments 1 and 2). The third hypothesis was that increased stimulus-stimulus compatibility would have a positive performance effect on the cross-task compatibility effect (Experiment 2). The results of Experiment 1 were consistent with the findings of Koch and Prinz, thus supporting Hypothesis 1. In regards to Hypothesis 2 for Experiment 1 and 2, older adults demonstrated a benefit for cross-task compatibility. There was no significant interaction between age and compatibility which suggested that the benefit for older adults from compatibility was not different from the benefit received for younger adults. Experiment 2 tested the 3rd hypothesis. The results of Experiment 2 demonstrated that on cross-task compatible trials when there is a further compatible element between the stimuli (stimulus-stimulus compatibility) on both tasks there is not a greater benefit for reaction time performance than cross-task compatibility alone. The results of these two experiments were discussed in terms of benefits to task-switching and the implications for task-switching and aging. Advisors/Committee Members: Allen, Philip A.

▼ The present study was a longitudinal extension of Bush and colleagues’ (in press) examination of the influence of amnestic mild cognitive impairment (MCI) on visual word recognition using a standard lexical decision task. The performances of cognitively healthy older adults, high functioning amnestic MCI (HMCI) patients, and low functioning amnestic MCI (LMCI) patients were compared. Results revealed that the LMCI group performed significantly worse than the unimpaired group on all Rey Auditory Verbal Learning Test measures except for the working memory span measure; HMCI performance, however, more closely resembled healthy adult performance on all portions except delayed recall. Consistent with numerous studies that have reported a mixed-case disadvantage in healthy older adults, lexical decision results revealed that the unimpaired group exhibited a mixed-case disadvantage at Time 1 and Time 2. The LMCI group exhibited a mixed-case disadvantage at Time 1, but this effect was attenuated at Time 2. Further, the LMCI group performed significantly worse when processing mixed-hue stimuli at Time 2, whereas the unimpaired group did not exhibit hue-processing deficits at Time 1 or Time 2. It appears as though LMCI patients suffer from both holistic and analytic processing deficits, although the holistic deficit is more pronounced. Results are discussed with regard to the hybrid model of visual word recognition proposed by Allen, Wallace, and Weber (1995) that attempts to merge cognitive (behavioral) and neuroscientific visual processing frameworks. Advisors/Committee Members: Allen, Philip A.

▼ Many studies have documented age-related decline of mental rotation abilities (e.g. Berg, Hertzog, and Hunt, 1982; and Hertzog, Vernon, and Rypma, 1993). None have attempted to design a training program to improve older adults’ mental rotation performance. This study’s focus was development of a program to benefit adults in mentally rotating block figures. Support training (environmental support or practice), and variability training (high or low) effects were tested. Environmental support provided colored “cue” blocks and allowed participants to manually rotate the figures. High and low variability varied in number of distinct rotation angles used in training. Effects of figure complexity were assessed by varying number of blocks and projections making up the figures. Fifty-one younger and 45 older adults completed a pretest, a 120-trial training session, and then a posttest. Both age groups improved accuracy and latency scores on the posttest, although environmental support training and variability training did not strongly influence scores. Little research has explored older adults’ mental rotation abilities on rotations over 180 degrees. While older adults’ latency never reached the same level as younger adults, their ability to accurately rotate figures over angles greater than 180 degrees improved more than younger adults’ from pretest to posttest. This study provided evidence that environmental support and high variability training may have helped older adults under some specific circumstances. It is apparent that more research is needed to develop effective mental rotation training that will work better than practice alone, especially for older adults Advisors/Committee Members: Murphy, Martin.

▼ This study examined the nature of attentional capacity across age. A rapid serial visual processing (RSVP) task was adapted from Li et al. (2002). Twelve participants (N=6 young, 6=old) completed 4 sessions across two weeks. Results verified that older adults manage attentional capacity by achieving global precedence in visual processing. Indeed, older adults showed a larger global precedence effect than did younger adults. Animal trials (whole objects) from natural scenes (Task 1) aided accuracy of letter discrimination (Task 2) in a dual task scenario, but no such advantage occurred for component features of geometric shapes. In lieu of these findings the decision complexity advantage theory is discussed in which greater processing efficiency can be achieved through the use of progressively larger perceptual units of analysis. This suggests a compensatory model for age maintenance in higher order visual processing despite age-related sensory and motor declines. Quite simply, it appears that a large part of what we think of as skill is really learning to use larger perceptual units (“chunking”), and that over the life span, older adults become progressively better at chunking perceptual information. Advisors/Committee Members: Allen, Philip.