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Simos and colleagues [241] examined reading in dyslexic children but they used a word recognition task instead of the passive viewing of words, as used by Salmelin and colleagues. Initial left inferior temporal activation was essentially equivalent between dyslexic and control groups but differences were evident at the next stage of temporalparietal area involvement. , there was reduced left temporal-parietal activation in dyslexics). They suggested that the functional connectivity between regions normally involved in reading was aberrant and that temporal-parietal regions are most likely involved in phonological decoding.

A recent review of MEG studies in this area is offered by Roberts and colleagues [243]. A brief discussion of Asperger’s syndrome was included under the Motor section since there is no significant delay in language development for this syndrome. Instead there is a lack of nonverbal communication skills. Since approximately 30% of autistic patients also have an associated seizure disorder [242], Lewine and colleagues [244] compared ASD children with children diagnosed as Landau-Kleffner syndrome (LKS), a childhood neurological disorder characterized by sudden or gradual loss of the ability to understand and use spoken language and an abnormal EEG.

12 A. MEG and ECoG traces for SCD entering longitudinal fissure from left side of rabbit cortex. Note polarity reversal across MEG channels. B. Computer model of SCD in cortical strip. Partial arc (black) represents SCD wave propagating into longitudinal fissure. , 1999a One noninvasive clinical application unique to MEG is the identification of sensory and language functions in the brain in order to facilitate surgical planning for removal of tumors or epileptogenic tissue and to reduce the risks of language deficits.