Exercise Effects on Word Learning
Condition: Aging; Aphasia
MeSH terms: Aphasia
Study type: Interventional

Summary: 
      The aging Veteran population will substantially increase over the next 10 years, as the 24.9%
      of Veterans who are currently between 55-64 years of age join the 38.5% who are already over
      age 65. The risk of stroke more than doubles each decade after age 55, which places Veterans
      at an ever-increasing risk of suffering stroke-related language impairment (i.e., aphasia).
      Difficulty retrieving words, which negatively impacts psychosocial well-being and quality of
      life, is the most common complaint in healthy aging and aphasia. Word retrieval interventions
      to maintain or restore communicative function are needed. Studies have shown that physical
      exercise can improve word learning in young adults. This study will investigate the effects
      of exercise on word learning in aging and aphasia. The results will help the us understand
      how exercise may be used to optimize word retrieval interventions for our aging Veterans.
    

Detailed description: 
      Difficulty retrieving the right word to communicate a message is the most common complaint in
      healthy older adults and individuals with stroke-induced language impairment (i.e., aphasia).
      Novel word learning paradigms have been used to investigate a variety of behavioral and
      neuromodulatory approaches to improve word retrieval deficits. Previous novel word learning
      studies have shown that physical exercise can improve long term recall in healthy young
      adults and that increased levels of dopamine may be responsible for this effect; however, no
      studies have investigated the effects of exercise on novel word learning in older adults and
      individuals with aphasia, and very little is known about the mechanisms that support
      exercise-enhanced word learning in these populations.

      The aims of this study are to:

      1) to identify the novel word learning paradigm that facilitates immediate and long-term word
      recall 2a) to investigate how acute, moderate-intensity exercise alters levels of serum
      brain-derived neurotrophic factor (BDNF) and plasma dopamine 2b) to describe and quantify the
      association between novel word learning and any observed changes in serum BDNF and plasma
      dopamine.

      This research will provide a platform for future investigations of immediate exercise effects
      on word learning, which are essential for achieving our long-term goal of developing
      exercise-based word retrieval interventions for healthy older Veterans and Veterans with
      aphasia.

      A within subjects crossover design will be used to address Aims 1, 2a and 2b. Subjects will
      complete aerobic exercise or stretching (training) before engaging in Study Only or Retrieval
      Practice (learning). Subjects will be counterbalanced within and across conditions. Sixteen
      healthy older adults (65-89 years) and 16 individuals with aphasia (35-89 years), will be
      recruited. The study will comprise 18 sessions over 12 weeks. In Week 1, subjects will
      undergo baseline blood draws, a physical assessment, cognitive and language assessments, and
      a practice word learning task. In Weeks 2-12, subjects will complete the four conditions.
      Each condition will last two weeks, with a one-week break between conditions. In each
      condition, training and learning sessions will take place on Monday, Wednesday and Friday.
      Training: Subjects will engage in 30 minutes of moderate-intensity cycling or gentle upper
      and lower limb stretching (control) prior to engaging in a novel word learning task.
      Learning: Familiar objects (e.g., cup) will be paired with nonwords (e.g., flark). In the
      Study Only paradigm, object/nonword pairs will be presented three times across three days
      (Monday, Wednesday, Friday). In the Retrieval Practice paradigm, object/nonword pairs will be
      presented during the first session (Monday). In subsequent sessions (Wednesday, Friday),
      subjects will be asked to recall the nonword name of presented objects. Corrective feedback
      will be provided on each trial. Testing: Recognition and recall testing without corrective
      feedback will be administered immediately after learning (short-term memory), before training
      in the second and third learning session (overnight consolidation) and one week after
      learning (long-term memory). Blood Draws: Three blood samples will be taken at baseline
      (rest, 30 minutes, 60 minutes). In each of the four conditions, blood samples will be taking
      during the first and third learning session (at rest, after training, after learning, and 15
      minutes after learning). Whole blood will be collected in plain tubes and in
      anticoagulant-treated tubes for subsequent serum BDNF and plasma dopamine analysis by ELISA.
      Samples will be analyzed in triplicate to increase reliability.
    

Intervention name(s): Retrieval Practice + Moderate Intensity Exercise; Retrieval Practice + Gentle Stretching; Study Only + Moderate Intensity Exercise; Study Only + Gentle Stretching
Intervention type(s): Behavioral; Behavioral; Behavioral; Behavioral
Intervention description(s): Subjects will engage in 30 minutes of moderate-intensity cycling prior to word learning using Retrieval Practice (active retrieval during learning); Subject will engage in 30 minutes of gentle upper- and lower- limb stretching prior to word learning using Retrieval Practice (active retrieval during learning); Subjects will engage in 30 minutes of gentle stretching prior to word learning using Study Only (no active retrieval during learning); Subjects will engage in 30 minutes of gentle stretching prior to word learning using Study Only (no active retrieval during learning)
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: 2x2 crossover design comparing two learning paradigms (Study Only vs. Retrieval Practice) and two training conditions (Moderate Intensity Exercise vs. Gentle Stretching)
Masking: None (Open Label)
Primary purpose: Other
Keywords: aerobic exercise; learning; language; cognition