Using event related brain potentials (ERPs), we examined the neurocognitive basis of phonological discrimination of phoneme /h/ in native English speakers and Francophone late second language (L2) learners, as a function of L2 proficiency and stimulus/task demands. In Experiment 1, native and non-native (L2 only) phonological contrasts were presented as syllables during a task that directed attention to phonological form. Phonological categorization was assessed with MMN, N2b and P3b effects. In Experiment 2, the same contrasts were presented as words/ pseudowords during a task that directed attention to semantics. Phonological discrimination was assessed with N400 pseudoword effects. High proficiency L2 learners displayed similar ERPs as native speakers in both experiments; low proficiency L2 learners showed discrimination of non-native contrasts in Experiment 1 (directed attention task) only. Thus, L2 phonological discrimination by late learners may depend on stimulus/task factors and occurs in a wider range of contexts as L2 proficiency improves.

Studies of concurrent central, and autonomic activity using a conventional event-related potential (ERP) oddball paradigms, are considered useful in elucidating the relationship between central and autonomic responses, but the autonomic response tends to overlap. A new method was used to decompose and score overlapping skin conductance responses (SCR). This method enabled examination of dynamic relationships of phasic SCR, prestimulus electroencephalogram (EEG), and ERP to auditory target stimuli in 50 normal adults. SCR amplitude was negatively correlated to EEG and N200 amplitude. The SCR amplitude changes over time exhibited an exponential decline opposite to those of N200, alpha, and beta. All the fitted exponential functions had a time constant of 1–2 min. The findings suggest that a N200 component, active in the auditory sensory discrimination, is concomitant with the SCR. The narrow range of the time constant may provide a clue to the conjoint processes underlying central and autonomic adaptive functions.

Event-related potentials were recorded from 80 participants ranging in age from 7 to 24 years while they attended selectively to stimuli with a specified color (red or blue) in an attempt to detect the occurrence of target stimuli. Color attention effects were identified as frontal selection positivity (FSP; 140–275 ms), selection negativity (SN; 150–300 ms), and N2b (200–450 ms), whereas target detection was reflected in P3b (300–700 ms). There were age-related decreases in the latencies of FSP, N2b, and P3b that paralleled decreases in reaction time and error rates. Also, the SN amplitude increased with advancing age, whereas both N2b and P3b showed changes in scalp topography. These results represent neurophysiological evidence that the efficiency of visual selective processes increases during childhood and adolescence. Developmental growth may take place at both relatively early and late levels of visual selective information processing.

Event-related potentials were recorded from 80 participants ranging in age from 7 to 24 years while they attended selectively to stimuli with a specified color (red or blue) in an attempt to detect the occurrence of target stimuli. Color attention effects were identified as frontal selection positivity (FSP; 140–275 ms), selection negativity (SN; 150–300 ms), and N2b (200–450 ms), whereas target detection was reflected in P3b (300–700 ms). There were age-related decreases in the latencies of FSP, N2b, and P3b that paralleled decreases in reaction time and error rates. Also, the SN amplitude increased with advancing age, whereas both N2b and P3b showed changes in scalp topography. These results represent neurophysiological evidence that the efficiency of visual selective processes increases during childhood and adolescence. Developmental growth may take place at both relatively early and late levels of visual selective information processing.