BACKGROUND: Depressive disorders are a group of neuropsychiatric disorders that cause significant distress and impairment in social, occupational, and other important areas of functioning. In the last decade, Brain-Computer Interfaces based-neurofeedback training appears as an innovative therapy for this condition and other neuropsychiatric disorders, allowing to volitionally self-regulate brain activity and behavior. Up to date, non-invasive neurofeedback training have been built on different techniques, including EEG, NIRS and fMRI. OBJECTIVES: This systematic review aims to evaluate the clinical application of fMRI neurofeedback training and its efficacy on treating depressive disorders. As a secondary objective, we intend to extract additional information on the neurofeedback training technique, in order to provide recommendations for future research. METHODS AND ANALYSIS: The systematic review complies with the PRISMA guidelines and it was submitted to PROSPERO registration. We will only include randomized control trials assessing participants with a depressive disorder. The intervention of interest is real-time fMRI neurofeedback training, the comparison of interest will be placebo neurofeedback, another active non-neurofeedback control or no treatment. The primary outcome will be effects on behavior (symptomatology/disease severity reduction). The secondary outcomes will assess quality of life, acceptability and adverse effects. Finally, we will evaluate other outcomes regarding brain MRI metrics (BOLD activation/connectivity), cognitive tasks performance, and physiology measures. At least two reviewers will independently select studies, extract data and assess the risk of bias. If methodologically possible, for primary and secondary outcomes, a meta-analysis will be performed and the data will be presented in summary tables of results using the GRADE approach. STRENGTH AND LIMITATIONS: As the number of studies on neurofeedback is increasing every year, and better quality of evidence is available, this systematic review, will include only randomized control trials. To our knowledge, this is the first systematic review assessing randomized control trials on fMRI neurofeedback training as a neurorehabilitation approach on depressive disorders. The main limitation of this systematic review might arise from the low number of extant RCTs.

The study was conducted in a rubber tree (Hevea brasiliensis Muell. Arg.) plantation plot of the clone IAN 3087 with the objetive of investigating the pattern of soil matric potential in relation to the distance from the tree trunk.. The study area was located in Piracicaba, SP, Brasil (latitude 22° 43' S, longitude 47°38' W and altitude 576 m), on a "terra roxa estruturada" soil.Matric soil water potential was determined using mercury manometer tensiometers localized at regular distances from the trunk, in two directions: between rows and between trees in the row. Toe root system was sampled by augers, according to tensiometers localizations.The lowest values of matric potential occured at the di stances 1. 25 m and O. 625 m from the trunk. between rows. As far as 2.5 m from the trunk the matric potential did not change significantly. ln the tree row, the values viii.were more negative at the middle of the distance between the trees than at 0.54 m from the trunk. Low values were observed at depths shallower than 37. 5 cm and at depths below 112. 5 cm.Toe sampling of the root system showed that up to 1.6 m from the tree trunk and in the soil layer O to 30 cm, 54.08% of the total sampled root system was present. As far as 2.2 m from the tree trunk the root density was very low. ln the tree row the highest densi ty was in the soil layer O to 30 cm. ln general, matric potential distributions reflected root densi ty dis. tributions and the information is useful for rubber tree crop management practices. * * tensiômetro com coluna quebrada.