Brain Activity During Strategic Planning
Condition: Healthy Volunteers
Study type: Observational

Summary: 
      This study will locate areas in the brain that help people devise action plans to carry out
      complex tasks requiring use of strategy. The ability to plan strategically is impaired in
      patients who have had a stroke affecting the front parts of the brain. This study will use
      functional magnetic resonance imaging (fMRI) to examine the activity of different areas of
      the brain during the formulation and execution of plans.

      Right-handed healthy volunteers between 18 and 60 years of age may be eligible for this
      study. Participants come to the NIH Clinical Center four to five times to complete the
      following procedures:

      Visit 1 - Screening

        -  Medical history

        -  Physical and neurological examinations

      Visit 2 - MRI brain scan (if one has not been done within the past year)

      MRI - This test uses a strong magnetic field and radio waves to obtain images of the brain.
      The scanner is a metal cylinder surrounded by a magnetic field. The subject lies on a table
      that can slide in and out of the scanner, wearing earplugs to muffle loud noises that occur
      during the scanning.

      Visits 3 to 5 - Task training sessions and two fMRI scans

      Functional MRI involves taking MRI scans while the subject performs a task in order to learn
      about changes in brain regions that are involved in the performance of the task. Subjects are
      trained in two tasks (see below) and then perform the tasks while in the MRI scanner.

        -  Task 1: The subject presses computer keys in response to the direction of arrows shown
           on the computer screen. The keys are pressed according to a given set of rules the
           subject is taught.

        -  Task 2: This task is similar to task 1, but the subject is also asked to remember
           certain previous actions and responses.
    

Detailed description: 
      OBJECTIVES

      Efficient behavior requires the ability to generalize from previous experiences. This can be
      achieved by behavioral strategies. We use many behavioral strategies; some strategies have
      strict S-R associations -stop at the RED light-; others are modifiable -balancing skills of a
      ballerina that becomes very useful during rock climbing- and serve as abstract strategies
      that enable solving problems.

      Strategy use is common in our behavioral repertoire. A strategy can be defined as a set of
      computations associated with the act of planning and directing overall operations and
      movements involved in a task. A behavioral strategy that conscious behaving primates
      spontaneously adopted in order to maximize their rewards have been well characterized in the
      literature. These are called "Repeat-Stay"/"Change-Shift" strategy, and were shown to be
      associated with prefrontal neuronal activity during multi-unit intra-cortical recordings,
      clearly indicating a special role played by the prefrontal cortex in computing strategy use.
      It is important to understand how the human brain computes and processes strategies. This
      study aims at understanding the activation patterns, and neuronal connectivity in the human
      brain when engaged in tasks that require strategies. We hypothesize that application of
      strategies to solve tasks would show specifically and significantly increase Blood
      Oxygenation Dependant (BOLD) signal, particularly the fronto-polar cortex (PFp), ventral and
      orbitofrontal prefrontal cortex (PFV+o) in the human brains.

      STUDY POPULATION

      The two experiments described in this protocol may recruit up to 61 (6 for the pilot study)
      adult healthy volunteers.

      DESIGN

      The study will consist of functional Magnetic Resonance Imaging (fMRI). The fMRI will consist
      of two separate experiments: (1) the strategy experiment and (2) the memory control
      experiment. Data will be analyzed separately for each part of the experiment: Responses to
      tasks will be collected and this data (response times, accuracy rates) will be searched for
      statistically significant differences using linear contrasts in an ANOVA model.

      The imaging fMRI data will be analyzed for statistically significant functional activations
      by using an implementation of the General Linear Model (GLM) (R. Turner et al., 1998; K. J.
      Friston et al., 2005) in Statistical Parametric Mapping (SPM).

      OUTCOME MEASURES

      We propose to acquire response data (response times, error rates), and functional brain
      activation data using fMRI. Therefore, we would have two outcome measures.

      From the response data we will evaluate statistically significant differences in response
      times, error rates, learning curves.

      From the BOLD fMRI data, the main outcome would be task specific neural activations that
      would regress with the behavioral tasks in a General Linear Model.

      These measures will further our understanding about how the human brains use strategies
      during complex task performance. This will lay the foundation to our understanding for how we
      are capable of generalizing our experiences from specific instances. Such knowledge will also
      improve our understanding of various aspects of movement genesis, and is likely to eventually
      shed light on various movement disorders including psychogenic movement disorders and chorea
      among others.
    

Time perspective: Prospective
Keywords: Neural Networks; Cortical Activation; Strategy; fMRI; Healthy Volunteer; HV