Study of Brain Activity During Speech Production and Speech Perception
Condition: Developmental Articulation Disorder; Stuttering
MeSH terms: Stuttering; Articulation Disorders
Study type: Observational

Summary: 
      The purpose of this study is to gain a better understanding of the brain's activity and
      organization in the development of speech disorders. It will compare brain activity in people
      with normal speech development with those who stutter or who have a phonological disorder (a
      deficit in how the brain processes speech sounds).

      Stuttering and phonological disorders emerge during the critical period of speech development
      between 2.5 and 12 years of age. During this period, the brain is much more adaptable for
      speech development than it is after puberty. This study will examine how the brain
      organization for speech production and perception develops normally during the critical
      period and how the normal pattern is altered when stuttering and phonological disorders
      become chronic problems, persisting throughout life.

      Volunteer adults and children with and without speech disorders may participate in this
      study. Eligibility screening will include a brief neurological and physical examination and
      tests to determine normal speech or a speech disorder. The speech testing will be videotaped.
      The subject will speak aloud, describe pictures, recall words or numbers, imitate speech
      sounds and words, and perform some listening tests.

      Study participants will undergo magnetic resonance imaging (MRI) to study brain activity. For
      this procedure, the subject lies on a stretcher that is moved into a donut-shaped machine
      with a strong magnetic field. During the MRI scan, the subject will perform simple tasks,
      such as listening to speech or other sounds and saying nonsense words. The procedure should
      take less than 60 minutes, and usually takes from 20 to 40 minutes.
    

Detailed description: 
      This is a study of two developmental speech production disorders, which emerge during the
      critical period of speech development between 2.5 and 12 years of age. During this critical
      period there is considerably greater brain plasticity for speech functioning which disappears
      following puberty. Our purpose is to determine how normal brain organization for speech
      production and perception develops during the critical period and how this normal pattern is
      altered when stuttering and phonological disorders become chronic problems, persisting
      throughout the life span. Functional MRI and magnetoencephalography (MEG) are non-invasive
      methodologies suitable for research in these disorders in children. New methodologies using
      fMRI and MEG provide the first opportunity for the study of speech production both in
      normally developing children as well as children and adults with stuttering and/or
      phonological disorders. Our hypothesis is that, with development, the brain organization for
      speech production becomes less distributed involving fewer brain regions, and that
      phonological processing mechanisms become lateralized to the left hemisphere during the
      critical period of speech development. This research will address whether the brain regions
      involved in speech are more diffuse and less selective in persons who develop chronic
      stuttering and phonological disorders, leading to a less efficient dynamic system for speech
      production.
    

Keywords: Functional Magnetic Resonance Imaging; Stuttering; Speech Perception; Speech Production; Phonology; Development; Motor Control; Neural Networks; Phonological Disorders