Study of Brain Activity During Speech Production and Speech Perception
Developmental Articulation DisorderStutteringThe 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.
Activity of the Auditory Cortex During Speech Perception and Speech Production in Stuttering
StutteringThe goal of the study is to examine the cortical activity during speech perception and speech production in idiopathic stutterers compared to fluent speakers. Therefore, the noninvasive method of magnetoencephalography (MEG) is used. A better understanding for the complexity of speech perception and its pathology should be developed. Fundamental properties of stuttering are repetitions, prolongations, and blocks. In most cases stuttering emerges between 2 and 5 years of age. The auditory feedback should become less important during development, as soon as information about mispronounced words does not occur anymore. During speech development this control function should be adopted by other systems. In stutterers the dominance of the acoustic control should remain. Brain imaging studies with positron emission tomography (PET) or magnetic resonance imaging (MRI) show defects in the network of motor system, in the lateralization of speech areas, and functions of the auditory cortex. Magnetoencephalographic studies describe a similar variety as cause of stuttering. There may be defects in the auditory feedback, a modification of the lateralization of speech areas, or an alteration of co-action of motor planning and auditory system. The benefit of magnetoencephalography is a very good temporal resolution in the range of milliseconds combined with good spatial resolution. Therefore, it is well suited to examine the dynamics of cortical processing during stuttering. In this study evoked components of the auditory systems related to complex sounds, vocals, consonant-vocal combinations, and single words are analyzed. Differences of these components in the auditory cortices of stutterers and fluent speakers are hypothesized as well in temporal structure as in localization and lateralization.
Correlation of Family History, Age at Onset & Severity of Stuttering
StutteringChildhoodThe aim of this study is to Detect the influence of the family history of stuttering (distance of relative) on the onset and severity of stuttering in children in these families. Also to explore developmental differences among young stutterers.