Influence of language structure on brain-behavior development.

Lack of exposure to specific sensory patterns during critical periods of development can result in a lack of responsiveness to those stimuli in adulthood. The present study extends these observations to native speakers of Japanese, a language which does not contain the contrastive /r/ and /l/ sounds present in English. Both electrophysiological (P3 event-related evoked potential) and behavioral results indicate deficient or absent discrimination of /r/ versus /l/ sounds in Japanese adults compared to native speakers of English.

Midlatency auditory evoked responses: P1 abnormalities in adult autistic subjects.

MLR recordings from a group of 11 high-functioning adult autistic subjects were compared with those from a control group of 11 normal subjects. Components selected for analysis were "Pa", the maximum positivity in the 25-40 msec latency range following stimulus onset, "P1", the maximum positivity within the 50-65 msec latency range, and "Nb," the maximum negative deflection in the 40-50 msec latency range. Statistical analyses of amplitude and latency data were conducted using repeated measures analysis of variance and t test group comparisons.

P3 responses to prosodic stimuli in adult autistic subjects.

Autistic persons are known to have serious abnormalities in speech prosody. The present study attempted to ascertain whether autistic persons could discriminate and/or recognize prosodic contrasts in auditory stimuli. A group of 11 adult autistic subjects with normal IQ and an age-matched group of normal subjects were studied electrophysiologically and behaviorally during presentations of prosodic and phonemic stimuli.

Midlatency auditory evoked responses: differential effects of a cholinergic agonist and antagonist.

The effects of a cholinergic antagonist (scopolamine) and agonist (physostigmine) on the auditory middle latency evoked responses (MLRs) were studied in 7 normal male volunteers. Scalp recordings were made from a central (Cz) electrode referenced to linked ear lobes on one channel and to a non-cephalic, sternovertebral reference on a second channel. Three components were statistically analyzed for changes in latency and amplitude: Pa, with peak positivity in the 25-40 msec latency range, Nb, with peak negativity 40-50 msec, and P1, with peak positivity 50-65 msec.

Auditory brainstem evoked responses in autistic children.

Auditory brainstem evoked responses (ABRs) were studied in 16 autistic children. Three children had severe delays in wave I latency, indicating defective functioning of the peripheral auditory pathway. The remaining subjects also had delayed wave I latency but only for right ear stimulation at the lowest stimulus intensity.