Bill Kanasky, Jr., Ph.D. explains how cortisol, the brain’s primary stress hormone, can significantly impair witness performance during testimony. He describes how elevated cortisol levels, produced during perceived threats, impair cognitive functions such as memory, decision-making, and emotional regulation. Bill introduces the stress-performance curve, noting that optimal performance occurs at moderate stress levels (between 4 and 6 on a 10-point scale). When cortisol levels are too high, the brain shifts from logical, prefrontal cortex functioning into survival mode, triggering fight, flight, or freeze responses.
Bill urges attorneys to monitor their witnesses closely for early signs of rising cortisol, such as changes in facial expression, posture, tone, and speech. Once stress exceeds a 7, it becomes very difficult to recover, as cortisol can remain elevated for hours and often triggers adrenaline, amplifying the problem. He emphasizes the need for proactive breaks at the first signs of stress escalation to prevent overexplaining, guessing, or emotional outbursts during deposition.
To counter cortisol’s effects, Bill outlines a training protocol that includes education, skill development, and systematic desensitization. Witnesses must understand the stress response, learn to self-monitor their stress levels, and practice breathing, pacing, and positive internal dialogue. Witnesses must be neurocognitively trained to manage the foreign experience of a deposition and understand what may trigger emotional responses. Gradual exposure to emotionally triggering stimuli, such as graphic evidence or hostile questioning, helps the brain adapt and remain calm. Lastly, Bill stresses that effective witness prep must go beyond strategy and incorporate neuroscience to preserve witness credibility and performance under pressure.