Biofeedback and Self-regulation

, Volume 2, Issue 1, pp 43–57 | Cite as

Effect of feedback contingencies on the control of occipital alpha

  • Thomas Mulholland
  • Peter Eberlin


Ten color transparencies were presented 30 times each to ten normal adults in response to changes in their occipital-parietal EEG's. By means of a feedback paradigm, detected alphas caused each slide to flash and stay on as long as alpha persisted, and then to turn off when alpha attenuated, according to four different contingency conditions. For half of the feedback trials, stimulus presentation depended on alpha detection in only one hemisphere and was not influenced by changes in the simultaneously recorded contralateral EEG. For the other feedback trials, stimulus presentation was bilaterally contingent. These contingency configurations were compared with sham feedback, a noncontingent condition during which slide presentation was controlled by a prerecorded tape. For both alpha and no-alpha, the ratio of mean duration over standard error\(({{\bar X} \mathord{\left/ {\vphantom {{\bar X} {SE}}} \right. \kern-\nulldelimiterspace} {SE}})\) was used as a quantification of the EEG response to visual stimulation. It was assumed that larger ratios indicated increased control of the EEG. Compared with the sham condition, all feedback contingencies produced greater\({{\bar X} \mathord{\left/ {\vphantom {{\bar X} {SE}}} \right. \kern-\nulldelimiterspace} {SE}}\) ratios, and hence, improved control of the EEG. The highest ratios were obtained during unilateral feedback from the EEG in which the occurrence of alpha elicited the visual stimulus. The results show that contingency between a visual stimulus and the EEG is an important parameter with regard to experimental control of the EEG.


Visual Stimulus Stimulus Presentation Visual Stimulation Contingency Condition Slide Presentation 
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  1. Boudrot, R. An alpha detection and feedback control system.Psychophysiology 1972,9 461–466.Google Scholar
  2. Goodman, D. ALFIE: Collection of EEG alpha under feedback control using time series analysis.Psychophysiology 1973,10 437–440.Google Scholar
  3. Eberlin, P., & Mulholland, T. Bilateral differences in parietal-occipital EEG induced by contingent visual feedback.Psychophysiology 1976,13 212–218.Google Scholar
  4. Lewis, C. N., & McLaughlin, T. J. Baseline and feedback EEG correlates of interview behavior.Psychophysiology 1976,13 302–306.Google Scholar
  5. Mulholland, T. Objective EEG methods for studying covert shifts of visual attention. In F. J. McGuigan & R. A. Schoonover (Eds.),The psychophysiology of thinking. Academic Press: New York, 1973, pp. 109–151.Google Scholar
  6. Mulholland, T. Biofeedback as scientific method. In J. Beatty & G. Schwartz (Eds.)Biofeedback theory and research. Academic Press: New York, 1977 (in press).Google Scholar
  7. Mulholland, T., McLaughlin, T. J., & Benson, F. Feedback control and quantification of the response of EEG alpha to visual stimulation.Biofeedback and Self-Regulation 1976,1 411–422.Google Scholar

Copyright information

© Plenum Publishing Corp. 1977

Authors and Affiliations

  • Thomas Mulholland
    • 1
  • Peter Eberlin
    • 1
  1. 1.Psychophysiology LaboratoryVeterans Administration HospitalBedford

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