Ian Armstrong and Scott C. Steffensen, Psychology
Introduction
Biofeedback is a process by which a person learns to control physiological functions of their body that they would otherwise not be conscously aware of. This is accomplished by relaying real-time information back to the user in the form of data or a game. The user then modifies their physiological activity in order to achieve set goals through a process of operant conditioning. Neurofeedback is a form of biofeedback that utilizes EEG monitoring to collect a person’s electrical brainwave activity and display it back to them. In this experiment, the method in which that feedback is displayed to the subject is through a video game format.
Recent research indicates that neurofeedback may be effective in improving cerebellar function and balance. Hammond (2011) used a neurofeedback procedure which places electrodes just beneath electrode sites O1 and O2 (areas lateral to midline on back of the head) to treat patients with balance disorders. The treatment was used in four cases and Hammond observed discernible improvements in balance after two to three sessions of neurofeedback training. Problems within the cerebellum are impicated in balance disorders, which is a site of the brain that is damaged in chroic druge abuse from an addiction (Hammond 2011). If balance can be improved through neurofeedback training, it is possible that this technique may improve addict brain function and physiology. This study originally aimed to discover whether or not this was the case, but changed due to the difficulty in recruiting addicts and due to the research needs of the addiction lab. This study, while similar, instead involved individuals from Dr. Steffensen’s lab and examined whether or not binocular rivalry was affected with caffeine (commonly understood to be an addictive drug) use. Binocular rivalry is the poorly-understood process by which competing visual information will cause one visual field to “flip”. This flipping of the visual field occurs at a measurable frequency and appears on an EEG. This study aimed to discover both the effects of caffeine on binocular rivalry and whether or not this showed a measurable effect on an EEG.
Methodology
I initially planned to perform a study on neurofeedback and addiction, but due to the difficulty recruiting patients, my research mentor had me assist him with a caffeine study that was being performed in the lab. While this study was similar in nature to my originally proposed one (in that it involved EEG and addictive substances), the methods changed drastically. Participants for the study were students recruited from Dr. Scott Steffenson’s Addiction Laboratory at Brigham Young University. Participants were male or female and all reported to drink caffiene either occasionally or regularly. Approval for the study was given by Brigham Young University’s Institutional Review Board.
The subjects first underwent a control binocular rivalry test for 120 seconds with dual color glasses. An image of overlapping red and violet arrows was displayed, and the subject pressed one of two buttons to indicate the direction of the arrow they perceived. After this control test, participants would be given a dose of caffeine equivalent to 1 milligram per killogram of body weight via a powdered energy drink. Participants would then be asked to wait for thirty minutes without talking or doing physical activity to allow the dose of caffeine to reach its full effect. The subjects would then perform another 120 seconds of binocular rivalry pressing buttons that corresponded to either the right or the left arrow depending on how fast the image “flipped”. During this entire process, the subjects were monitored with EEG on the C1 and O2 sites along with an addition to the A1 cite on the earlobe. The EEG was connected with conductive gel to ensure that it maintained a good signal. After recording, raw EEG data was analyzed via IGOR for significant differences between pre and post caffeine recordings on both hemispheres of the cerebrum.
Results
The data initially appeared promising, with what qualitatively looked like an increase in EEG activity in the Post-Caffeine binoculary rivalry. Despite this, no consistent difference could be found in the subjects’ data, even though some subjects seemed to be affected in the expected way individually. The data did show that caffeine substantially increased the frequency of binocular rivalry, which shows promise for future studies if nothing else.
Discussion
Caffeine can affect dopaminergic systems in the brain which can increase binocular rivalry. This study shows that caffeine does increase the frequency of binocular rivalry between subjects. The differences between subjects in terms of EEG analysis was problematic, and probably due to the limited group we had to sample from (Dr. Steffenson’s lab worker’s) along with the differences in gender and caffeine use between subjects. In addition to this the EEG recordings were sometimes inconsistent and potentially inaccurate due to problems with applying the electrodes or differing hair density between subjects. Ultimately, the results indicate that there is potential for further exploration of binocular rivalry with EEG and caffeine’s affect on binocular rivalry.
Conclusion
Further data analysis is necessary before drawing conclusions from this study. From our initial analysis, it appears that there was no statistically significant difference between preand post-caffeine intake incidence of binocular rivalry. Despite this, we did see that binocular rivalry was affected by caffeine in almost all of the subjects recorded. In regards to my originally proposed study involving addicts and neurofeedback, there is potential for a study here but it seems to be outside the resources of an ORCA project.
References
- Hammond, C. (2005). Neurofeedback to improve physical balance, incontinence, and swallowing. Journal of Neurotherapy, 9(1), 27-36.