David Wolk
University of Pennsylvania, Neurology, Faculty Member
Determining the relationship between age and Alzheimer's disease (AD) presentation is important to improve understanding and provide better patient services. We used AD patient data (N = 7815) from the National Alzheimer Coordinating... more
Determining the relationship between age and Alzheimer's disease (AD) presentation is important to improve understanding and provide better patient services. We used AD patient data (N = 7815) from the National Alzheimer Coordinating Center database and multinomial logistic regression to investigate presentation age and first cognitive/behavioral symptoms. The odds of having a nonmemory first cognitive symptom (including impairment in judgment and problem solving, language, and visuospatial function) increased with younger age (P <.001, all tests). Compared with apathy/withdrawal, the odds of having depression and "other" behavioral symptoms increased with younger age (P <.02, both tests), whereas the odds of having psychosis and no behavioral symptom increased with older age (P <.001, both tests). There is considerable heterogeneity in the first cognitive/behavioral symptom experienced by AD patients. Proportions of these symptoms change with age with patient...
Research Interests:
A number of studies have utilized the Remember/Know paradigm to determine event-related potential (ERP) correlates of recollection and familiarity. However, no prior work has been specifically directed at examining the processing involved... more
A number of studies have utilized the Remember/Know paradigm to determine event-related potential (ERP) correlates of recollection and familiarity. However, no prior work has been specifically directed at examining the processing involved in making the Remember/Know distinction. The following study employed a two-step recognition memory test in which participants first decided whether they recognized a word from a prior study list (Old/New decision); if they did, they then determined whether it was recognized on the basis of recollection ('Remember' responses) or familiarity ('Know' responses). By time-locking ERPs to the initial Old/New decision, processing related to making the introspective Remember/Know judgment was isolated. This methodology revealed a posterior negativity that was largest for 'Remember' responses. Previous work has described a late posterior negativity which appears to be related to the search for and recapitulation of study details. Su...
Research Interests: Psychology, Biological Psychology, Cognitive Science, Decision Making, Electroencephalography, and 17 moreAdolescent, Recognition memory, Brain Mapping, Evoked Potentials, Humans, Judgment, Cerebral Cortex, Female, Male, Biological, Reaction Time, Remember-Know, Adult, Neurosciences, Verbal Learning, Decision Process, and Contingent Negative Variation
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
There is need for a valid and reliable biomarker for HIV Associated Neurocognitive Disorder (HAND). The purpose of the present study was to provide preliminary evidence of the potential utility of neuronal functional connectivity measures... more
There is need for a valid and reliable biomarker for HIV Associated Neurocognitive Disorder (HAND). The purpose of the present study was to provide preliminary evidence of the potential utility of neuronal functional connectivity measures obtained using magnetoencephalography (MEG) to identify HIV-associated changes in brain function. Resting state, eyes closed, MEG data from 10 HIV-infected individuals and 8 seronegative controls were analyzed using mutual information (MI) between all pairs of MEG sensors to ...