Clinical Research Directory

Modulating Goal-directed Navigation Using Noninvasive Brain Stimulation

Our specific aim is to examine the effects of TMS on spatial processing during goal-directed navigation. In these experiments the investigators will utilize a scalp-recorded brain oscillation called right posterior theta that is believed to index the sensitivity of the parahippocampal cortex to spatial context. Here the investigators will asked whether this electrophysiological signal can be modulated up or down using TMS while participants engage in virtual navigation tasks, and if so, whether it would affect the spatial encoding of rewards and subsequent choices during task performance.

Exploring to Remediate Behavioral Disturbances of Spatial Cognition

Spatial navigation (SN) has been reported to be one of the first cognitive domains to be affected in Alzheimer's disease (AD), which occurs as a result of progressive neuropathology involving specific brain areas. Moreover, the epsilon 4 isoform of Apolipoprotein-E (APOE-ε4) has been associated with both sporadic and familial late-onset AD and patients with Mild Cognitive Impairment (MCI) due to AD are more likely to progressively deteriorate. It will be investigated (i) whether amyloid-positive MCI patients and APOE-ε4 carriers show subtle changes of SN prior to the overt symptoms of AD disorientation, both in virtual and in naturalistic open-space tasks, and (ii) the effect of a combined treatment of computer-based and virtual reality tasks in those presenting such an impairment. Finally, (iii) threshold algorithms based on physiological parameters and gait analysis will be set up to support senior citizens at increased risk in maintaining their ability to independently navigate urban environments. Different types of navigational guidance will be examined on a sample of 76 older adults by the AppleGame, and the Detour Navigation Test-modified version. It is expected that patients with MCI due to AD and APOE-ε4 carriers show reduced SN performances than individuals with subjective cognitive impairment and healthy controls in the experimental tasks, with potential improvements after cognitive rehabilitation. Altered SN performances of individuals at increased risk to develop AD may inform future advanced technological applications in providing valuable information on threshold algorithms based on physiological parameters and gait analysis during elders' traveling to unfamiliar locations.