The present study investigated the relation between academic performance and ratings of executive functioning in children aged 6–11 from four countries: Sweden, Spain, Iran, and China. Ratings of executive functioning were made by both parents and teachers using the Childhood Executive Functioning Inventory (CHEXI). The results showed that the Chinese sample was generally rated as having more executive deficits compared to the other samples. The finding that executive functioning deficits are exacerbated in China is most likely the result of cultural biases. Boys were generally rated as having poorer executive functioning compared to girls, except in Iran where parents, but not teachers, rated girls as having poorer executive functioning compared to boys. However, this opposite pattern of results found for Iran is not likely to reflect true gender differences in executive functioning. Despite some differences in the levels of executive functioning across countries, both the inhibition and working memory subscales of the CHEXI were related to academic achievement in all four countries, except for CHEXI parent ratings in China. Altogether, the results indicate that the CHEXI may be used as a screening measure for early academic difficulties, although cultural biases clearly have to be taken into consideration.

The data presented here had been originally collected for a research project entitled 'Sleep EEG spectral analysis in psychophysiological insomnia and normal sleep subjects'. This article describes the data of 11 subjects, referred to Sleep Disorders Research Center (SDRC) in Kermanshah, Iran. The data includes 14 EEG, 6 EOG, and 3 EMG channels, with a sampling ratio of 256 Hz. It includes power spectral features in segments of 30 s for each channel, and nonlinear analysis parameter. Also, the complete demographic and polysomnography specifications are attached.

Introduction: Visual sleep-stage scoring is a time-consuming technique that cannot extract the nonlinear characteristics of electroencephalogram (EEG). This article presents a novel method for sleep-stage differentiation based on sonification of sleep-EEG signals using wavelet transform and recurrent neural network (RNN). Methods: Two RNNs were designed and trained separately based on a database of classical guitar pieces and Kurdish tanbur Makams using a long short-term memory model. Moreover, discrete wavelet transform and wavelet packet decomposition were used to determine the association between the EEG signals and musical pitches. Continuous wavelet transform was applied to extract musical beat-based features from the EEG. Then, the pretrained RNN was used to generate music. To test the proposed model, 11 sleep EEGs were mapped onto the guitar and tanbur frequency intervals and presented to the pretrained RNN. Next, the generated music was randomly presented to 2 neurologists. Results: The proposed model classified the sleep stages with an accuracy of >81% for tanbur and more than 93% for guitar musical pieces. The inter-rater reliability measured by Cohen’s kappa coefficient (κ) revealed good reliability for both tanbur (κ = 0.64, p < 0.001) and guitar musical pieces (κ = 0.85, p < 0.001). Conclusion: The present EEG sonification method leads to valid sleep staging by clinicians. The method could be used on various EEG databases for classification, differentiation, diagnosis, and treatment purposes. Real-time EEG sonification can be used as a feedback tool for replanning of neurophysiological functions for the management of many neurological and psychiatric disorders in the future.

Objectives: Obstructive sleep apnea (OSA) is a major health problem that has been associated with endocrine dysfunction in the hypothalamic‐pituitary‐gonadal (HPG) and hypothalamic‐pituitary‐adrenal (HPA) axes. This study investigated cortisol, testosterone, and the testosterone/cortisol ratio in patients with OSA compared to normal sleepers. Methods: Thirty‐nine OSA patients diagnosed by overnight polysomnography (PSG) were divided into three groups, including ten mild OSA patients, 16 patients with moderate OSA, and 13 patients with severe OSA according to the apnea‐hypopnea index (AHI). In addition, 13 normal sleepers with normal PSG findings were recruited as the control group. Serum levels of cortisol, testosterone, and sex hormone‐binding globulin (SHBG) were measured using enzyme‐linked immunosorbent assay (ELISA). Results: There were no significant differences between the normal sleepers and the three subtypes of OSA in terms of total and free testosterone levels ( P > .1). The results showed significantly higher levels of cortisol in the severe OSA group compared to the normal sleepers and the two other subtypes of OSA ( P < .01). In addition, the testosterone/cortisol (T/C) ratio was significantly lower among the severe OSA compared to the moderate OSA patients ( P = .01). A significant correlation was observed between minimal SpO2 and AHI (r=−0.69, P < .01), cortisol and AHI ( r = .47, P < .01) and cortisol and minimal SpO2 ( r = −.26, P = .06). Conclusion: According to the findings, OSA is linked to HPA axis activity in severe OSA patients but not among the mild and moderate subtypes of the disorder.