Frontal Gamma Asymmetry as a Forensic Tool for Emotional Valence in a Murder Case Study
DOI:
https://doi.org/10.15540/nr.13.3.319Keywords:
Frontal gamma asymmetry, Quantitative EEG (qEEG), Emotional valence, Forensic neuroscience, Mens rea assessment, Brodmann Area 9 (BA9)Abstract
In criminal cases, forensic evaluations often hinge on determining a defendant’s competence and intent. Assessing underlying emotional states presents unique challenges, as self‑reports may be unreliable or incomplete. In this exploratory single‑case study, we illustrate how psychological assessments can be combined with quantitative EEG (qEEG) and source localization techniques to examine neural markers of emotional processing in the context of a murder trial. Emotional valence toward key individuals and events was derived from a proprietary frontal gamma asymmetry protocol. Although this innovative metric offers unique insights, it has received limited independent replication and should therefore be interpreted cautiously and in conjunction with established measures such as frontal alpha asymmetry. Key procedural covariates, including the defendant’s medication (sertraline), were documented because serotonergic agents can modulate baseline asymmetry patterns. Findings indicated general alignment between neural patterns and reported affect, but we emphasize that these observations reflect preliminary insights from a single individual and require validation in larger samples before supporting broader forensic applications.
References
Arns, M., Etkin, A., Hegerl, U., Williams, L. M., DeBattista, C., Palmer, D. M., Fitzgerald, P. B., Harris, A., deBeuss, R., & Gordon, E. (2015). Frontal and rostral anterior cingulate (rACC) theta EEG in depression: Implications for treatment outcome? European Neuropsychopharmacology, 25(8), 1190–1200. https://doi.org/10.1016/j.euroneuro.2015.03.007
Beauregard, M., Lévesque, J., & Bourgouin, P. (2001). Neural correlates of conscious self-regulation of emotion. The Journal of Neuroscience, 21(18), Article RC165. https://doi.org/10.1523/JNEUROSCI.21-18-j0001.2001
Bonnstetter, B. J., Bonnstetter, R. J., Hebets, D., & Collura, T. F. (2015). Behavioral and cognitive profile assessment system (U.S. Patent No. 9,060,702). U.S. Patent and Trademark Office.
Bonnstetter, B. J., Bonnstetter, R., Hebets, D., & Collura, T. F. (2016). Validation process for ipsative assessments (Canadian Patent No. 2,808,691). Canadian Intellectual Property Office.
Bonnstetter, R., & Collura, T. (2020). Brain activation imaging in emotional decision making and mental health: A review—Part 1. Clinical EEG and Neuroscience, 52(2), 98–104. https://doi.org/10.1177/1550059420916636
Bonnstetter, R. J., Collura, T., Hebets, D., & Bonnstetter, B. J. (2012). Uncovering the belief behind the action. NeuroConnections, Winter, 20–23.
Bonnstetter, R. B., Collura, T., Zalaquett, C., & Wang, H. (2022). EEG microstates in relation to emotional decision-making. In D. R. Chartier, M. B. Dellinger, J. Evans, & H. K. Budzynski (Eds.), Introduction to quantitative EEG and neurofeedback: Advanced applications (3rd ed., pp. 219–234). Elsevier Academic Press.
Bonnstetter, R. J., Gehrig, E., & Hebets, D. (2018). Response process validation protocol using neurophenomenological gamma asymmetry. NeuroRegulation, 5(3), 93–102. https://doi.org/10.15540/nr.5.3.93
Bonnstetter, R. J., Hebets, D., & Wigton, N. L. (2015). Frontal gamma asymmetry in response to soft skills stimuli: A pilot study. NeuroRegulation, 2(2), 70–85. https://doi.org/10.15540/nr.2.2.70
Bzdok, D., Langner, R., Caspers, S., Kurth, F., Habel, U., Zilles, K., & Eickhoff, S. B. (2011). ALE meta-analysis on facial judgments of trustworthiness and attractiveness. Brain Structure and Function, 215(3–4), 209–223. https://doi.org/10.1007/s00429-010-0287-4
Cantor, D. (2016). Integration of frontal gamma asymmetry as a forensic tool for emotional valence in a murder case. Presentation at Proceedings of the 18th World Congress of Psychophysiology (IOP2016) of the International Organization of Psychophysiology (IOP), 108, 65.
Chow, R. T. S., Yu, R., Geddes, J. R., & Fazel, S. (2025). Personality disorders, violence and antisocial behaviour: Updated systematic review and meta‑regression analysis. The British Journal of Psychiatry, 227(1), 471–491. https://doi.org/10.1192/bjp.2024.226
Collura, T. F., & Bonnstetter, R. J., (2020). Brain activation imaging in emotional decision making and mental health: A review part 2. Clinical EEG and Neuroscience, 52(2), 105–113. https://doi.org/10.1177/1550059420916642
Collura, T. F., Wigton, N. L., Zalaquett, C., Chatters, S., & Bonnstetter, R. J. (2016). The value of EEG-based electromagnetic tomographic analysis in human performance and mental health. Biofeedback, 44(2), 72–80.
Collura, T. F., Zalaquett, C., & Bonnstetter, R. J. (2014a). Seeing inside the client’s mind. Counseling Today, 57(6), 24–27.
Collura, T. F., Zalaquett, C., Bonnstetter, R. J., & Chatters, S. (2014b). Toward an operational model of decision making, emotional regulation, and mental health impact. Advances in Mind-Body Medicine, 28(4), 18–33.
Davidson, R. J. (1998). Affective style and affective disorders: Perspectives from affective neuroscience. Cognition and Emotion, 12(3), 307–330. https://doi.org/10.1080/026999398379628
Etkin, A., Egner, T., & Kalisch, R. (2011). Emotional processing in anterior cingulate and medial prefrontal cortex. Trends in Cognitive Sciences, 15(2), 85–93. https://doi.org/10.1016/j.tics.2010.11.004
Ford, J. D., & Courtois, C. A. (2021). Complex PTSD and borderline personality disorder. Borderline Personality Disorder and Emotion Dysregulation, 8(1), Article 16. https://doi.org/10.1186/s40479-021-00155-9
Foxe, J. J., & Snyder, A. C. (2011). The role of alpha-band brain oscillations as a sensory suppression mechanism during selective attention. Frontiers in Psychology, 2, Article 154. https://doi.org/10.3389/fpsyg.2011.00154
Gehrig, E., & Bonnstetter, R. (2021). Styles Insights Technical Manual (Version 1.0). Target Training International, Ltd.
Goldin, P. R., McRae, K., Ramel, W., & Gross, J. J. (2008). The neural bases of emotion regulation: Reappraisal and suppression of negative emotion. Biological Psychiatry, 63(6), 577–586. https://doi.org/10.1016/j.biopsych.2007.05.031
Jensen, O., & Mazaheri, A. (2010). Shaping functional architecture by oscillatory alpha activity: Gating by inhibition. Frontiers in Human Neuroscience, 4, Article 186. https://doi.org/10.3389/fnhum.2010.00186
Klimesch, W. (2012). Alpha-band oscillations, attention, and controlled access to stored information. Trends in Cognitive Sciences, 16(12), 606–617. https://doi.org/10.1016/j.tics.2012.10.007
Knott, V., Telner, J., Lapierre, Y., Browne, M., & Horn, E. (1996). Quantitative EEG in the prediction of antidepressant response to imipramine. Journal of Affective Disorders, 39(3), 175–184. https://doi.org/10.1016/0165-0327(96)00003-1
Lehmann, D., Ozaki, H., & Pal, I. (1987). EEG alpha map series: Brain micro-states by space-oriented adaptive segmentation. Electroencephalography and Clinical Neurophysiology, 67(3), 271–288. https://doi.org/10.1016/0013-4694(87)90025-3
Leuchter, A. F., Cook, I. A., Hunter, A. M., Cai, C., Horvath, S. (2012). Resting-state quantitative electroencephalography reveals increased neurophysiologic connectivity in depression. PLoS ONE, 7(2), Article e32508. https://doi.org/10.1371/journal.pone.0032508
Nourse, V. F. (2002). Hearts and minds: Understanding the new culpability. New Criminal Law Review, 6(1), 361–402.
Ochsner, K. N., & Gross, J. J. (2005). The cognitive control of emotion. Trends in Cognitive Sciences, 9(5), 242–249. https://doi.org/10.1016/j.tics.2005.03.010
Palva, S., & Palva, J. M. (2007). New vistas for alpha-frequency band oscillations. Trends in Neurosciences, 30(4), 150–158. https://doi.org/10.1016/j.tins.2007.02.001
Pascual-Marqui, R. D. (2002). Standardized low-resolution brain electromagnetic tomography (sLORETA): Technical details. Methods and Findings in Experimental and Clinical Pharmacology, 24(Suppl. D), 5–12.
Scheeringa, R., Mazaheri, A., Bojak, I., Norris, D. G., & Kleinschmidt, A. (2011). Modulation of visually evoked cortical fMRI responses by phase of ongoing occipital alpha oscillations. The Journal of Neuroscience, 31(10), 3813–3820. https://doi.org/10.1523/JNEUROSCI.4697-10.2011
Teicher, M. H., & Samson, J. A. (2016). Annual research review: Enduring neurobiological effects of childhood abuse and neglect. Journal of Child Psychology and Psychiatry, 57(3), 241–266. https://doi.org/10.1111/jcpp.12507
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