Neurofeedback and traumatic brain injury: A literature review

Geoffrey May, MD Randall Benson, MD Richard Balon, MD Nash Boutros, MD

Department of Psychiatry and Behavioral Neurosciences

Wayne State University School of Medicine Detroit, Michigan, USA

BACKGROUND: Neurofeedback is a form of biofeedback whereby a patient can learn to control measurements of brain activity such as those recorded by an electroencephalogram. It has been explored as a treatment for sequelae of traumatic brain injury, although the use of neurofeedback remains outside the realm of routine clinical practice.

METHODS: Google ScholarTM was used to find 22 examples of primary research. Measures of symptom improvement, neuropsychological testing, and changes in subjects’ quantitative electroencephalogram were included in the analysis. A single reviewer classified each study according to a rubric devised by 2 societies dedicated to neurofeedback research.

RESULTS: All studies demonstrated positive findings, in that neurofeedback led to improvement in measures of impairment, whether subjective, objective, or both. However, placebo-controlled studies were lacking, some reports omitted important details, and study designs differed to the point where effect size could not be calculated quantitatively.

CONCLUSIONS: Neurofeedback is a promising treatment that warrants double-blind, placebo-controlled studies to determine its potential role in the treatment of traumatic brain injury. Clinicians can advise that some patients report improvement in a wide range of neuropsychiatric symp- toms after undergoing neurofeedback, although the treatment remains experimental, with no standard methodology.

EEG Alpha Asymmetry, Depression, and Cognitive Functioning

Ian H. Gotlib
Stanford University, Stanford, CA, USA

CharanRanganathand J. Peter Rosenfeld
Northwestern University, Evanston, USA

Davidson (1993) has proposed that hemispheric asymmetry in prefrontal activation, as measured by electroencephalographic (EEG) power in the alpha band (8± 13Hz), is related to reactivity to affectively valenced stimuli. David- son has proposed further that asymmetry is a stable trait, and that left frontal hypoactivation is a stable marker of vulnerability to depression.  In Study 1, we tested Davidson’ s formulations by examining differences in frontal EEG alpha asymmetry among currently depressed, previously depressed, and never depressed subjects. As expected, currently and previously depressed subjects showed left frontal hypoactivation relative to never depressed controls, but did not differ signifcantly from each other. In Study 2, we explored the associations among frontal EEG asymmetry, response to a negative mood induction procedure, endorsement of dysfunctional cognitions, and attentional processing of valenced stimuli. Contrary to predictions, frontal EEG asymmetry was unrelated to mood reactivity and cognitive functioning. Theoretical and methodological implications of these findings are discussed.