Accuracy and neural correlates of blinded mediumship compared to controls on an image classification task.

In this study, a classification task asked participants to look at 180 facial photographs of deceased individuals (photographs were taken years prior to their deaths) and guess the cause of death from three equiprobable categories: heart attack; death by firearm; or car accident. Electroencephalogram (EEG) and electrocardiogram (ECG) data were simultaneously collected during the task. The participants included individuals who claimed "mediumistic" (psychic) abilities and controls who claimed no mediumistic ability. Pooled data showed accurate guesses for the cause of death (partial η2 = 0.12; p = 0.004), and control subjects were primarily responsible for this effect (partial η2 = 0.11; p = 0.005). EEG and ECG differences were found between the mediums and controls. Control participants had larger amplitude event-related potentials (ERP) following the presentation of the images than the mediums, between 80 and 110 ms, and between 200 and 350 ms. This could be interpreted as reflecting greater attention and less response inhibition by controls as compared to the mediums. Participants in the control group also had lower average heart rates than the mediums, possibly indicating less stress during the task. Speculations and limits regarding why controls performed better than mediums are discussed.

Sleep ontogenesis revisited: a longitudinal 24-hour home polygraphic study on 15 normal infants during the first two years of life.

The sleep organization of 15 normal infants (seven boys, eight girls) was studied at their homes during six 24-hour periods, i.e. at 3, 6, 9, 12, 18, and 24 months of age, using the Oxford Medical System. Sleep states and stages were scored visually at 30-second intervals, according to Rechtschaffen and Kales' criteria, adapted for children by Guilleminault. All sleep parameters were analyzed for the entire 24-hour period, i.e. during both the nocturnal and the diurnal part of the nycthemere. The results showed a continuous decrease in total sleep time, rapid eye movement (REM) sleep, and indeterminate sleep, and also an increase in waking time, quiet sleep, and stages 1 and 2 sleep. Except for slow-wave sleep, which remained very stable for the different ages, analysis of variance applied to the data showed clear age and day-night effects on sleep ontogenesis. Modifications with age were more precocious and more pronounced for the diurnal part of the nycthemere, especially as regards REM sleep. For the nocturnal part, there was a significant increase in sleep efficiency and in the length of the REM period after 12 months of age, while total sleep duration and number of awakenings decreased. In addition to normative data for clinical use, this study provides three new interesting results related to the maturation of sleep mechanisms and functions: 1) the high stability of the percentage of slow-wave sleep along these 2 years, 2) the presence (from 12 months of age) of a stage 2/REM sleep ratio equal to one, and a sleep change occuring earlier, during the diurnal rather than the nocturnal part of the nycthemere. The first two points could be regarded as indexes of sleep maturation reflecting developmental and neurophysiological changes in central nervous system structures. The third point underlines the importance of the circadian rhythm and the concept of "experience" in the maturation of sleep.

Narcolepsy in children.

The clinical and polygraphic characteristics of narcolepsy in children were established on the analysis of 97 reported cases in children (including 12 personal cases). In idiopathic narcolepsies (77 cases) narcoleptic attacks occurred in 97% of the cases, cataplexy in 80.5%, hypnagogic hallucination in 39% and sleep paralysis in 29%; 13% of the children had the tetrad; dyssomnia was a prominent feature. Polygraphic data showed no significant differences between adults and children. In symptomatic narcolepsies (20 cases): cataplexy was the prominent feature occurring in 95% of the cases, 26% of the children had status cataplecticus; in these narcoleptic-cataplectic syndromes there was often an absence of polygraphic evidence of narcolepsy. Symptomatic narcolepsy should be suspected in cases where narcolepsy is detected in preteenage children, where cataplectic attacks are abnormally frequent, where there is an absence of polygraphic evidence of classical narcolepsy (although this criterion may not apply in the case of younger children) or where human leukocyte antigen typing for DR2 is negative. An association with a Niemann-Pick disease type C was found in 12 out of the 20 symptomatic cases, this association merits further study.