The emergence of the EEG dominant rhythm across the first year of life.

The spectral composition of EEG provides important information on the function of the developing brain. For example, the frequency of the dominant rhythm, a salient features of EEG data, increases from infancy to adulthood. Changes of the dominant rhythm during infancy are yet to be fully characterized, in terms of their developmental trajectory and spectral characteristics. In this study, the development of dominant rhythm frequency was examined during a novel sustained attention task across 6-month-old (n = 39), 9-month-old (n = 30), and 12-month-old (n = 28) infants. During this task, computer-generated objects and faces floated down a computer screen for 10 s after a 5-second fixation cross. The peak frequency in the range between 5 and 9 Hz was calculated using center of gravity (CoG) and examined in response to faces and objects. Results indicated that peak frequency increased from 6 to 9 to 12 months of age in face and object conditions. We replicated the same result for the baseline. There was high reliability between the CoGs in the face, object, and baseline conditions across all channels. The developmental increase in CoG was more reliable than measures of mode frequency across different conditions. These findings suggest that CoG is a robust index of brain development across infancy.

A label isn't just a label: Brief training leads to label-dependent visuo-cortical processing in adults.

The current study examines the extent to which hearing individual-level names (e.g., Jimmy) and category-level labels (e.g., Hitchel) paired with novel objects impacts neural responses across a brief (6 min) learning period. Event-related Potentials (ERPs) were recorded while adult participants (n = 44) viewed and heard exemplars of two different species of named novel objects. ERPs were examined for each labeling condition and compared across the first and second half of the learning trials (∼3 min/half). Mean amplitude decreased for the P1 and increased for the N170 from the first to the second half of trials. The decrease in P1 was right lateralized. In addition, the P1 amplitude recorded over right occipitotemporal regions was greater than left occipitotemporal areas, but only for objects paired with individual-level labels. Category-level labels did not show regional P1 differences. The N250 component was greatest over the right occipitotemporal region and was enhanced for objects labeled with individual-level relative to category-level names during the second half of trials. Overall, these findings highlight the unfolding of label-dependent visual processing across a short training period in adults. The results suggest that linguistic labels have an important, top-down impact, on visual processing and that label specificity shapes visuo-cortical responses within a 6-min learning period.