Sean Turner

Mentor: Dr. Sara Burke
College of Medicine
 
"From early on in school I had an interest in science and desire to discover the way things work. Growing up I witnessed the negative effects aging can have on cognitive ability in my grandparents and family friends. A favorite catchphrase of my grandpa was “don’t get old.” I could not help but wonder why aging (as a natural process) could have such deleterious effects in some individuals and yet negligible effects in other individuals. Joining the Burke Lab with its concentration in cognitive neuroscience of aging my sophomore year allowed me to ask just such questions. I discovered that to be involved in research is to be able to ask these questions and push the limits of knowledge. With the help of Dr. Burke and all the members of the lab, I was able to formulate empirically testable questions to address the mystery of aging."

Major

Psychology and Philosophy

Minor

N/A

Research Interests

  • Memory and Aging
  • Cognitive Neuroscience
  • Moral Psychology

Academic Awards

  • Bright Futures Scholarship 2012-16
  • Elizabeth Faye Logan Memorial Scholarship 2012
  • Dean's List 2012-15
  • University Scholars Program 2015-16

Organizations

  • Friends for Life of America
  • College of Liberal Arts and Sciences Ambassadors
  • Psychology Club

Volunteer

  • UF Health Shands Hospital
  • Noah's Endeavor
  • Balance 180 Gymnastics

Hobbies and Interests

  • Golf
  • Tennis
  • Cooking
  • Travel

Research Description

Visual Pattern Separation in Young and Aged Rats
Normal aging is associated with emerging deficits in cognitive function that include impairments in object recognition and discrimination, which have been observed in humans (Yassa et al 2011 Hippocampus) and in animal models (Burke et al 2011 Behav Neurosci). Specifically, pattern separation, or the ability to encode and store similar stimuli as distinct neural representations, appears particularly vulnerable to the effects of aging (Wilson IA et al 2006 Trends Neurosci). The current study has two major goals first, is to determine whether age selectively impairs the ability to distinguish between stimuli with many overlapping features, that is, when the objects are perceptually similar. Second, is to determine whether the dentate gyrus is required for this type of visual object discrimination. In order to systematically vary the difficulty of visual discrimination problems, object pairs were created from LEGO blocks, such that the two members of a pair differed only in configuration and not in size or texture. Young (6-10 m) and aged (24-30 m) male Fischer 344 x Brown Norway hybrid rats were trained on an object discrimination task where two objects are presented, and one object of the pair is rewarded with food that can be retrieved by displacing the object. Rats first learned the object discrimination rule with a pair of standard objects that differed in shape, size, color, and texture. Then, rats completed the task with two different pairs of LEGO objects. One pair was visually distinct (easy discrimination). The other LEGO object pair shared multiple features, that is, they were visually similar (difficult discrimination). Studies have demonstrated that the perirhinal cortex is critical for pattern separation computations that support the discrimination of similar visual stimuli in humans, (Barense et al. 2010), monkeys (Bussey et al., 2003) and rats (Barkto et al. 2007). It has also been shown that the dentate gyrus is involved in tasks that require associating a particular object with a particular location (Lee and Solivan 2008). It has not been demonstrated whether the dentate gyrus is required for pattern separation tasks that do not involve a spatial memory component. To test whether the dentate gyrus is required for this visual object discrimination task, cannula will be surgically implanted into bilateral dentate gyrus. Rats will be infused with muscimol, a GABAA receptor agonist, to temporarily inactivate the dentate gyrus during testing on the LEGO discrimination task. The data gathered here will reveal whether the dentate gyrus in the hippocampus is required for visual discriminations with high perceptual overlap.