Doubting the double-blind: Introducing a questionnaire for awareness of experimental purposes in neurofeedback studies.

A double-blind neurofeedback study tested whether participants could become aware of the experiment's purpose. Using a contingency awareness questionnaire developed from consciousness research, 5 out of 20 subjects correctly guessed that the experiment aimed to manipulate their attention and multisensory perception in line with their group assignment. The questionnaire took about 25 minutes to complete. The authors call for replication before applying the questionnaire in clinical neurofeedback studies, noting both the strengths and limitations of the approach and the increasing importance of double-blinding in this field.

Study at a glance

Abstract

Double-blinding subjects to the experiment's purpose is an important standard in neurofeedback studies. However, it is difficult to provide evidence that humans are entirely unaware of certain information. This study used insights from consciousness studies and neurophenomenology to develop a contingency awareness questionnaire for neurofeedback. We assessed whether participants had an awareness of experimental purposes to manipulate their attention and multisensory perception. A subset of subjects (5 out of 20) gained a degree of awareness of experimental purposes as evidenced by their correct guess about the purposes of the experiment to affect their attention and multisensory perceptions specific to their double-blinded group assignment. The results warrant replication before they are applied to clinical neurofeedback studies, given the considerable time taken to perform the questionnaire (∼25 min). We discuss the strengths and limitations of our contingency awareness questionnaire and the growing appeal of the double-blinded standard in clinical neurofeedback studies.