***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The P300 ( P3 ) event-related brain potential was elicited in a group of 50 children and young adults ( 4 - 20 years ) . A simple auditory task was employed in which subjects indicated with a finger movement when a r and omly occurring target tone ( high pitch ) was presented in a series of st and ard ( low pitch ) tones . The probability of the target tone was varied across conditions at 10 % , 30 % , or 50 % to assess possible developmental changes in P300 amplitude . Memory capacity was assessed with forward and reverse digit spans . Circumference of the head also was measured . P300 latency decreased with age , and P300 amplitude tended to become larger with age . Polynomial regression analyses revealed significant quadratic trends in these relationships , with changes leveling off for older subjects . Digit span and head circumference also were related curvilinearly to P300 values . Multiple regression analysis indicated that changes in age and memory span both predicted significant changes in P300 latency and amplitude . Target stimulus probability generally affected all subjects in a similar fashion , although the strength of the correlational relationships tended to decline with increases in probability . Developmental changes for the N1 , P2 , and N2 components from the st and ard stimuli also were obtained . The results are discussed in terms of previous P3 findings for children and their implication s for future studies A new off-line procedure for dealing with ocular artifacts in ERP recording is described . The procedure ( EMCP ) uses EOG and EEG records for individual trials in an experimental session to estimate a propagation factor which describes the relationship between the EOG and EEG traces . The propagation factor is computed after stimulus-linked variability in both traces has been removed . Different propagation factors are computed for blinks and eye movements . Tests are presented which demonstrate the validity and reliability of the procedure . ERPs derived from trials corrected by EMCP are more similar to a ' true ' ERP than are ERPs derived from either uncorrected or r and omly corrected trials . The procedure also reduces the difference between ERPs which are based on trials with different degrees of EOG variance . Furthermore , variability at each time point , across trials , is reduced following correction . The propagation factor decreases from frontal to parietal electrodes , and is larger for saccades than blinks . It is more consistent within experimental sessions than between sessions . The major advantage of the procedure is that it permits retention of all trials in an ERP experiment , irrespective of ocular artifact . Thus , studies of population s characterized by a high degree of artifact , and those requiring eye movements as part of the experimental task , are made possible . Furthermore , there is no need to require subjects to restrict eye movement activity . In comparison to procedures suggested by others , EMCP also has the advantage that separate correction factors are computed for blinks and movements and that these factors are based on data from the experimental session itself rather than from a separate calibration session This study demonstrates that the EEG phenotypes as described by Johnstone , Gunkelman & Lunt are identifiable EEG patterns with good inter-rater reliability . Furthermore , it was also demonstrated that these EEG phenotypes occurred in both ADHD subjects as well as healthy control subjects . The Frontal Slow and Slowed Alpha Peak Frequency and the Low Voltage EEG phenotype discriminated ADHD subjects best from controls ( however the difference was not significant ) . The Frontal Slow group responded to a stimulant with a clinical ly relevant decreased number of false negative errors on the CPT . The Frontal Slow and Slowed Alpha Peak Frequency phenotypes have different etiologies as evidence d by the treatment response to stimulants . In previous research Slowed Alpha Peak Frequency has most likely erroneously shown up as a frontal theta sub-group . This implies that future research employing EEG measures in ADHD should avoid using traditional frequency b and s , but dissociate Slowed Alpha Peak Frequency from frontal theta by taking the individual alpha peak frequency into account . Furthermore , the divergence from normal of the frequency b and s pertaining to the various phenotypes is greater in the clinical group than in the controls . Investigating EEG phenotypes provides a promising new way to approach EEG data , explaining much of the variance in EEGs and thereby potentially leading to more specific prospect i ve treatment outcomes Event-related brain potentials ( ERPs ) of 13 - 21-year-old autistic subjects and age-matched controls were elicited by auditory stimuli in a variation of orienting response paradigms . Unexpected , novel sounds ( bizarre concoctions of human , mechanical and computer sounds ) were r and omly inserted as probes in a sequence of expected , non-novel sounds ( the word ' me ' ) . In order to help ensure that both subject groups were attending to this stream of information , each subject was required to press a button to a specified target sound ( the word ' you ' ) also r and omly inserted in the sequence of expected non-novel sounds . The ERP results showed that in both groups , unexpected , novel probes and also targets evoked a different neurophysiological response than did expected , non-novel sounds . This suggests that the autistic group did not misperceive novel information as non-novel and were able to make simple classification decisions as accurately as normal controls . However , in the autistic group , there may be less ' processing ' of the novel probes and of targets : compared to the control group , the autistic group had smaller amplitudes of two long-latency components to novels and smaller P3b amplitudes to targets . The two components to novels were termed A/Pcz/300 ( A = auditory ; P = positive ; cz = electrode site of maximum amplitude ; 300 = latency in msec ) and A/Ncz/800 . In another sequence of sounds , subjects simply listened to frequently presented ' me ' sounds ( 90 % ) and infrequently presented ' you ' sounds ( 10 % ) . In this no-task condition , no differences between autistic and normal control subjects were found 
    Output:
    
The P300 latency and amplitude follow a maturational path from childhood to adolescence , result ing in a period that marks a plateau , after which degenerative effects begin .
/ SIGNIFICANCE It is hypothesized that latency and amplitude index different aspects of brain maturation .
The P300 latency possibly indexes neural speed or brain efficiency .
The P300 amplitude might index neural power or cognitive re sources , which increase with maturation