There was also a good review article in the september issue of Nature Review Neuroscience by Paula Tallal Improving language and literacy is a
matter of time
Abstract | Developmental deficits that affect
speech perception increase the risk of
language and literacy problems, which can
lead to lowered academic and occupational
accomplishment. Normal development and
disorders of speech perception have both
been linked to temporospectral auditory
processing speed. Understanding the role
of dynamic auditory processing in speech
perception and language comprehension
has led to the development of
neuroplasticity-based intervention strategies
aimed at ameliorating language and literacy
problems and their sequelae.
PDF copies available back channel too.
Wolfgang Keeser
Am 05.10.2004 um 13:49 schrieb Gruzelier, John H:
Have copied this off the journal website. Copies available back channel.
Original Article
Impaired auditory frequency discrimination in dyslexia detected with mismatch evoked potentials
Torsten Baldeweg, MD *, Alexandra Richardson, PhD, Sarah Watkins, MBBS, Christine Foale, MBBS, John Gruzelier, MA, PhD
Division of Neuroscience and Psychological Medicine, Imperial College School of Medicine, London, UK
*Correspondence to Torsten Baldeweg, Institute of Child Health and Great Ormond Street Hospital for Children NHS Trust, University College London Medical School, The Wolfson Centre, Mecklenburgh Square, London WC1N 2AP, UK
Abstract
Deficits in phonological skills appear to be at the heart of reading disability; however, the nature of this impairment is not yet known. The hypothesis that dyslexic subjects are impaired in auditory frequency discrimination was tested by using an attention-independent auditory brain potential, termed mismatch negativity (MMN) while subjects performed a visual distractor task. In separate blocks, MMN responses to graded changes in tone frequency or tone duration were recorded in 10 dyslexic and matched control subjects. MMN potentials to changes in tone frequency but not to changes in tone duration were abnormal in dyslexic subjects. This physiological deficit was corroborated by a similarly specific impairment in discriminating tone frequency, but not tone duration, which was assessed separately. Furthermore, the pitch discrimination and MMN deficit was correlated with the degree of impairment in phonological skills, as reflected in reading errors of regular words and nonwords. It is possible that in dyslexia a persistent sensory deficit in monitoring the frequency of incoming sound may impair the feedback control necessary for the normal development of phonological skills. Ann Neurol 1999;45:495-503
Received: 25 June 1998; Revised: 15 December 1998; Accepted: 16 December 1998
