Fornix Integrity and Reaction Time to Novel Scenes and Objects in Visual Recognition Memory

Poster Session D - Monday, April 15, 2024, 8:00 – 10:00 am EDT, Sheraton Hall ABC

Melissa Elder¹ (melder@gradcenter.cuny.edu); ¹CUNY Graduate Center

The fornix may play an important role in working and long-term visual recognition memory. Data borrowed from a study on the role of hippocampus in visual recognition memory was used in conjunction with DTI of the fornix to assess the relationship between the fornix integrity and task performance, in addition to reaction times. Two tasks were employed to separately evaluate working and long-term visual recognition memory, using indoor and outdoor naturalistic scenes and everyday objects. The subjects included 32 healthy adults, aged 18-44 whose tractography data was obtained with a Siemens 3 Tesla Prisma MRI Scanner to generate T2 weighted images. Analysis of fornix integrity was based on the total number of white matter fiber tracts, average length and diameter of the tracts, fractional anisotropy, mean diffusivity, average diffusivity, and radial diffusivity, using the left and right fornix as regions of interest (ROIs). Memory performance was calculated the percentage of correct responses. Average reaction times were recorded and evaluated in terms of difference scores between trials 1 and 3 for the working memory task, and separately for “old” versus “new” items on the long-term memory task. A negative correlation (p < 0.05) was found between reaction time for new images presented during the recognition task and fractional anisotropy of the combined left and right fornix, with the model being significantly enhanced by adding age as a co-variate. There was also a positive correlation (p < 0.05) between reaction time and accuracy for new images in the recognition task.

Topic Area: LONG-TERM MEMORY: Episodic