Developmental gender differences in the synchronization of auditory event-related oscillations.

OBJECTIVES: The aim of the present study was to explore the neurophysiologic origins of gender differences in auditory processing mechanisms of 7-10 year-old children by means of event-related oscillations. It was tested if the developmental changes in synchronization and magnitude of oscillations in different processing conditions depended on gender. METHODS: Eighteen girls and 18 boys aged 7-10 years were pair wise matched for age and were divided into two age groups. Auditory event-related potentials (ERPs) were recorded in passive, sensorimotor and working memory conditions. Phase-locking and single-trial magnitude of ERPs were analyzed in the delta (0.5-4 Hz), theta (4-7 Hz), slow (7-10 Hz), and fast (10-14 Hz) alpha frequency bands to test the effects of gender, age, and processing condition. RESULTS: The phase-locking of auditory delta, theta, and slow alpha oscillations increased with development only in girls, independently of task processing. Only for the theta phase-locking was this effect additionally affected by the motor-related task. No changes in the magnitude of oscillations accompanied these gender differences in synchronization except for parietal delta responses that also increased with development only in girls. CONCLUSIONS: The results demonstrate that gender differences in auditory ERPs basically originate from a stronger functional synchronization of oscillatory responses generated during stimulus processing. SIGNIFICANCE: The study provides evidence that the functional maturation of oscillatory auditory networks reflected by a progressive developmental increase of synchronization, is accelerated in girls relative to boys between 7 and 10 years of age.

Gender-specific development of auditory information processing in children: an ERP study.

OBJECTIVES: The aim of the present study was to evaluate the effects of gender on sensory and cognitive information processing in children by analyzing auditory event-related potentials (ERPs). The major questions were: (1) do ERPs differ between girls and boys aged 7-10years, (2) do gender differences in ERPs depend on the development with age, on task-processing demands, and on the development of neuroelectric networks as reflected by the spontaneous EEG? METHODS: Thirty-six healthy children (18 girls and 18 boys) were divided in two age groups (7- to 8- and 9- to 10-year-old). Boys and girls were pairwise matched for age. Auditory ERPs were analyzed in a passive listening condition (PLC), a simple reaction task (SRT) and a serial learning reaction task (SLRT), in which memory and sensorimotor processes were varied in a balanced way. Cognitive performance, reaction times (RTs), and the spontaneous electroencephalogram (EEG) were also measured. RESULTS: Cognitive performance improved earlier in girls than boys, whereas response speed was not affected by gender. Independent of processing demands, ERP components within 300ms after stimulation (N1, P2, N2 and P3) increased with development only in the group of girls. For later components, the developmental speeding of the parietal P3b component to task-relevant stimuli also tended to be more expressed in girls than boys, whereas a late frontal negative wave N400-700 was shorter in the girls than boys from the two age groups. Likewise, independently of age, the spontaneous EEG manifested a larger theta activity in girls than boys. CONCLUSIONS: Developmental changes of basic auditory processing mechanisms strongly depend on gender in children between 7 and 10years by being faster in girls. This gender-specific development of early ERP components is not modulated by processing demands, cannot be attributed to a faster cognitive maturation of girls, nor can it be explained with the gender-specific maturation of background neuroelectric networks. Rather, it reflects an accelerated functional activation of auditory processing networks in girls. Interestingly, the cognitive development was also faster in girls, but it occurred earlier than the functional activation of auditory processing networks. SIGNIFICANCE: This study provides evidence for accelerated neuroelectric (as reflected by spontaneous EEG), neurofunctional (as reflected by auditory ERPs), and neurocognitive (as reflected by learning performance) development in 7- to 10-year-old girls than boys.