A controlled study on the cognitive effect of alpha neurofeedback training in patients with major depressive disorder

Abstract

Cognitive deficits are core symptoms of depression. This study aims to investigate whether neurofeedback (NF) training can improve working memory (WM) performance in patients with major depressive disorder (MDD). The NF group (n = 40) underwent eight NF sessions and was compared to a non-interventional control group (n = 20). The NF protocol aimed to increase the individual upper alpha power in the parieto-occipital area of the scalp. Main cognitive variable was WM, which was measured pre- and post- training along with other variables such as attention and executive functions. EEG was recorded in both eyes closed resting state and eyes open task-related activity, pre- and post- NF training, and pre- and post- the NF trials within each session. A power EEG analysis and an alpha asymmetry analysis were conducted at the sensor level. Frequency domain standardized low resolution tomography (sLORETA) was used to assess the effect at brain source level. Correlation analysis between the clinical/cognitive and EEG measurements was conducted at both the sensor and brain source level. The NF group showed increased performance as well as improved processing speed in a WM test after the training. The NF group showed pre-post enhancement in the upper alpha power after the training, better visible in task-related activity as compared to resting state. A current density increase appeared in the alpha band (8–12 Hz) for the NF group, localized in the subgenual anterior cingulate cortex (sgACC, BA 25). A positive correlation was found for the NF group between the improvement in processing speed and the increase of beta power at both the sensor and brain source level. These results show the effectiveness of this NF protocol in improving WM performance in patients with MDD.

Upper Alpha Based Neurofeedback Training in Chronic Stroke: Brain Plasticity Processes and Cognitive Effects

“…Generally, successful modulation of EEG band power is associated with cognitive and behavioral improvements (Kropotov 2009; Gruzelier 2014; Kober et al 2015a, b; Hofer et al 2014; Reichert et al 2016). For instance, voluntary up-regulation of the upper alpha frequency band (UA, about 10–12 Hz) generally leads to improvements in working memory (WM) and short-term memory performance (Escolano et al 2011, 2012, 2013, 2014; Angelakis et al 2007; Nan et al 2012). It is assumed that alpha activity inhibits unnecessary or conflicting processes to the task being performed, thus facilitating attention and memory by actively suppressing distracting stimuli (Klimesch et al 2007).…”

“…We used an UA based NF training, since the two chronic stroke patients showed deficits in memory functions prior to the NF training. Based on the literature, UA based NF training should have specific positive effects on memory functions (Escolano et al 2011, 2012, 2013, 2014; Angelakis et al 2007; Nan et al 2012). We compared the results of the two stroke patients to the results of a healthy, elderly control group.…”

Cognitive Impairment Along the Course of Depression: Non-Pharmacological Treatment Options

“…One possible goal is enhancement of neurocognitive performances. A first study comparing the cognitive performances of a neurofeedback training group to a non-interventional control group in a sample of MDD patients (n = 60) showed significant improvement in working memory and processing speed with medium to large effect sizes [95]. However, there are some limitations that need to be considered, like the lacking of randomization and mixed depressive states of patients.…”

The effect of voluntary modulation of the sensory-motor rhythm during different mental tasks on H reflex

“…Power in 8-12 Hz band increased predominantly over central areas of the cortex, indicating that patients modulated sensory-motor mu rhythm rather than a wide-spread alpha rhythm. Recently there have been several controlled randomised studies involving patients which demonstrated that people can successfully learn to increase power in the upper alpha (10-12 Hz) frequency band, resulting in improved memory performance (Escolano et al 2014, Kober et al 2015. A person can also be trained to decrease SMR using NF.…”