Test of A Model of Representational Knowledge Stored in the Human Prefrontal Cortex
Condition: Intracranial Central Nervous System Disorder; Mental Disorder; Healthy
MeSH terms: Nervous System Diseases; Central Nervous System Diseases; Brain Diseases; Mental Disorders
Study type: Observational

Summary: 
      This study will examine the underlying mental processes that determine how people understand
      social behavior, remember information, and think. Language, planning, problem solving,
      reasoning, social behavior, and memory are the critical parts of cognition that make up daily
      life. This study will explore the association between performance on various experimental
      tasks and day-to-day functioning.

      Healthy normal volunteers and patients with certain kinds of brain damage (primarily focal or
      degenerative lesions of the human prefrontal cortex) or psychiatric disorders may be eligible
      for this study. Candidates with central nervous system trauma, disease or dysfunction will be
      screened with a routine neurological examination and history.

      Participants may be asked to complete written tests, sit in front of a computer monitor and
      press a key to indicate a decision about what appears on the screen (for example, whether a
      statement is accurate) and answer questions from a test examiner. A skin conductance response
      (SCR) test may be done along with some of the cognitive tests. SCR uses electrodes (pieces of
      metal attached to wires) placed on the fingers to measure the subject's emotional reaction to
      a test. Participants may also do an evoked response test, in which the subject watches words
      or scenes on a TV screen while his or her responses are recorded from electrodes placed on
      the scalp (similar to an electroencephalogram). The tests will be scheduled for an average of
      one session a week, with each session lasting from 30 minutes to 3 hours. Generally, 15
      sessions will be scheduled over a 1-year period. Special arrangements will be made to
      accommodate participants from out-of-town.

      Participants may have a magnetic resonance imaging (MRI) scan of the brain. This test uses
      radio waves and a strong magnetic field to picture structural and chemical changes in tissue.
      For the procedure, the subject lies on a table in a space enclosed by a metal cylinder (the
      scanner) for about 1 hour.

      In addition, some study subjects will be invited to participate in a training study designed
      to improve their planning or social behavior. Participation requires coming to NIH daily over
      a 1- to 2-month period for 1 to 2 hours each visit.
    

Detailed description: 
      The purpose of this protocol is to test a comprehensive model of the underlying knowledge
      representations stored in the human prefrontal cortex developed by the principal
      investigator. Utilizing a variety of standardized and experimental neuropsychological tasks
      and techniques, we will investigate hypotheses regarding the role of the dorsolateral
      prefrontal cortex in planning, problem-solving, and reasoning and the ventromedial prefrontal
      cortex in social cognition and emotional processing. We will ascertain the relationship
      between so-called "cold" cognitive processes such as planning and "hot" social processes such
      as attitude formation and specific brain regions within the prefrontal cortex. Besides
      cognitive paradigms, we will use skin conductance and event-related EEG recording techniques
      when subjects are performing selected cognitive tasks in order to determine the relationship
      between autonomic and central nervous system markers of emotional modulation and
      speed/duration of processing and task performance. The data we collect in this protocol will
      be of value in 1) Developing a model of the forms of knowledge representation stored in the
      human prefrontal cortex; 2) Developing outcome measures for drug and behavioral treatments
      for disorders of prefrontal cortex functions; and, 3) Developing biologically plausible
      computer models of the cognitive sub-components stored in the human prefrontal cortex that
      compose the complex skills referred to above.
    

Keywords: Cognition; Frontal Lobes; Frontotemporal Dementia; Focal Lesions; Executive Functions; Frontotemporal Lobe Dementia; Frontal Lobe; Frontal Lobe Dementia; Healthy Volunteer; HV; Normal Control