Faculty Bibliography

We administered a battery of neurocognitive tests to 100 HIV-positive men and women ages 50 to 70 seeking care at a large Northeastern urban HIV care clinic. Performance on neurocognitive assessments varied by demographic states. Across all assessments, approximately 28% of participants reached the threshold for borderline performance while 13% reached the threshold for impairment. When tests were grouped by domain of neurocognitive functioning, 12% of the sample met the threshold for impairment on executive functioning and 19% for processing speed. The findings demonstrate that neurocognitive declines may vary by domains of functioning, that disparities may exist across subpopulations of the seropositive aging population, and that these challenges may exist even in those actively engaged in HIV care.

The present study utilized functional near infrared spectroscopy (fNIRS) to detect neural activation differences in the orbitofrontal brain region between individuals with multiple sclerosis (MS) and healthy controls (HCs) during a working memory (WM) task. Thirteen individuals with MS and 12 HCs underwent fNIRS recording while performing the n-back WM task with four levels of difficulty (0-, 1-, 2-, and 3-back). Subjects were fitted with the fNIRS cap consisting of 30 'optodes' positioned over the forehead. The results revealed different patterns of brain activation in MS and HCs. The MS group showed an increase in brain activation, as measured by the concentration of oxygenated hemoglobin (oxyHb), in the left superior frontal gyrus (LSFG) at lower task difficulty levels (i.e. 1-back), followed by a decrease at higher task difficulty (2- and 3-back) as compared with the HC group. HC group achieved higher accuracy than the MS group on the lower task loads (i.e. 0- and 1-back), however there were no performance differences between the groups at the higher task loads (i.e. 2- and 3-back). Taken together, the results suggest that individuals with MS experience a task with the lower cognitive load as more difficult than the HC group, and the brain activation patterns observed during the task confirm some of the previous findings from functional magnetic resonance imaging (fMRI) studies. This study is the first to investigate brain activation by utilizing the method of fNIRS in MS during the performance of a cognitive task.

Neuropsychological and cognitive deficits are observed in the majority of persons with alcohol and drug use disorders and may interfere with treatment processes and outcomes. Although, on average, the brain and cognition improve with abstinence or markedly reduced substance use, better understanding of the heterogeneity in the time-course and extent of cognitive recovery at the individual level is useful to promote bench-to-bedside translation and inform clinical decision making. This study integrated a variable-centered and a person-centered approach to characterize diversity in cognitive recovery in 197 patients in treatment for a substance use disorder. We assessed executive function, verbal ability, memory, and complex information processing speed at treatment entry, and then 6, 26, and 52 weeks later. Structural equation modeling was used to define underlying ability constructs and determine the mean level of cognitive changes in the sample while minimizing measurement error and practice effects on specific tests. Individual-level empirical growth plots of latent factor scores were used to explore prototypical trajectories of cognitive change. At the level of the mean, small to medium effect size gains in cognitive abilities were observed over 1 year. At the level of the individual, the mean trajectory of change was also the modal individual recovery trajectory shown by about half the sample. Other prototypical cognitive change trajectories observed in all four cognitive domains included Delayed Gain, Loss of Gain, and Continuous Gain. Together these trajectories encompassed between 86 and 94% of individual growth plots across the four latent abilities. Further research is needed to replicate and predict trajectory membership. Replication of the present findings would have useful implications for targeted treatment planning and the new cognitive interventions being developed to enhance treatment outcomes.

This study examined the contribution of tactile and kinesthetic perceptions to handwriting legibility and speed of 177 Taiwanese children in first and second grade. Five standardized instruments assessed tactile and kinesthetic perceptions using handwriting legibility and speed as outcome measures. Fine motor coordination, mental processing speed, age, and gender were measured and served as covariates. Pearson correlations and regression analyses examined the relationship between handwriting and tactile and kinesthetic perceptions. Handwriting speed and legibility both significantly correlated with tactile perception, kinesthetic perception, and covariates. Results from the regression analysis supported tactile and kinesthetic perceptions as being significant predictors of both handwriting speed (F (6,170) = 25.87, p < .001, R-2 = .477) and legibility (F (6,170). = 11.043, p < .001, R-2 = .280). Tactile perception contributed more to handwriting speed and legibility than kinesthetic perception. Tactile and kinesthetic perception should be assessed when evaluating handwriting. When children have difficulty writing quickly or legibly, professionals should assess children's tactile and kinesthetic abilities.