Enhancing the Effects of Neurofeedback Training: The Motivational Value of the Reinforcers.

The brain activity that is measured by electroencephalography (EEG) can be modified through operant conditioning, specifically using neurofeedback (NF). NF has been applied to several disorders claiming that a change in the erratic brain activity would be accompanied by a reduction of the symptoms. However, the expected results are not always achieved.

Acne vulgaris: prevalence and clinical forms in adolescents from São Paulo, Brazil.

Background: Acne is a common disease in adolescents, but there are no epidemiological data for acne in Brazil.

Objectives: To estimate the prevalence and degree of acne in adolescents from Sao Paulo and study socio-demographic factors, family history and lifestyle, associated with the disease.

Methods: Cross-sectional study with 452 adolescents aged between 10 and 17 (mean=13.