Concussion Symptoms Exposed: How Brain Maps Reveal Hidden Performance Bottlenecks
This episode revealed fascinating insights about executive function fatigue, post-concussion patterns, and the specific brain circuits behind afternoon "bonking." Here's what Dr. Andrew Hill's analysis uncovered about optimizing mental performance through neurofeedback.
The Sports Car Brain with Brake Problems
When examining this athlete's cognitive performance, a striking pattern emerged: exceptional vigilance and focus (1.5 standard deviations above average) paired with a peculiar weakness in sustained inhibitory control.
"You've got a sports car brain in that aspect," Dr. Hill explained, describing the athlete's ability to maintain high-level attention and quickly activate cognitive resources. However, the data revealed something more complex.
The executive function test—20 minutes of monitoring stimuli and controlling responses—showed elite performance for the first 15 minutes, then a dramatic decline in what's called "response control" or the ability to "pump the brakes" on automatic reactions.
This isn't typical fatigue. This is a specific circuit breakdown.
The Hidden Concussion Signature
What made this case particularly interesting was the cold analysis approach. Dr. Hill interpreted the brain data without extensive medical history, yet immediately suspected head trauma based on the patterns.
"I have a sense, okay, he's an athlete, he's got his bell rung once or twice... hockey has a certain spot in my heart," Hill noted, before the athlete confirmed multiple concussions from hockey.
The telltale signs in the qEEG (quantitative electroencephalogram):
Slow Alpha Waves: Processing speed dragged 1.5 standard deviations below normal for his age—the classic "brain fog" signature of post-concussion syndrome.
Executive Function Fatigue: High performance that deteriorates specifically in sustained attention tasks, indicating damaged prefrontal circuits struggling to maintain inhibitory control.
Mixed Beta Patterns: Some areas showing excess activation (like muscles in spasm) while others showed insufficient control (like weakened muscles).
The Afternoon Bonk: A Circuit-Level Explanation
The athlete's description of afternoon performance crashes—"life was now coming at me and I wasn't really playing with it"—perfectly matched the neurofeedback data.
Here's the mechanism:
When prefrontal inhibitory circuits are compromised (often from head trauma), the brain compensates by "white-knuckling" cognitive control. This works for several hours but creates unsustainable metabolic demand on already-damaged neural networks.
The result? Predictable afternoon crashes where executive function, impulse control, and cognitive flexibility all deteriorate simultaneously.
"You have to sort of white knuckle your resources and step on the gas a little bit," Hill explained. "Push a little harder" than a normal brain would require for the same tasks.
Name Retrieval Anxiety: The Alpha Connection
One of the most relatable symptoms—difficulty retrieving names and words—directly connects to the slow alpha wave pattern found in the brain mapping.
Alpha waves (8-12 Hz) represent the brain's "idling speed" for internal processing. When alpha frequency drops below optimal ranges, it creates:
- Delayed word retrieval
- "Tip of the tongue" phenomena
- Short-term memory loading difficulties
- General cognitive sluggishness
"I'm like twice your age," Hill noted. "If I had that alpha speed dragging and spreading out, I'd be experiencing delayed recall for words and names and tip of the tongue stuff."
For a younger athlete to show these patterns indicates significant neural disruption, likely from cumulative head impacts.
The SMR Solution: Training Calm Alertness
The treatment approach focuses on SMR (sensorimotor rhythm) training—specifically targeting the 12-15 Hz frequency band that builds what neuroscientists call "calm alertness."
SMR training works by strengthening thalamocortical circuits responsible for:
- Inhibitory control (the "brake" system)
- Sustained attention without hypervigilance
- Efficient neural processing with minimal metabolic cost
"We're looking at optimizing those circuits," Hill explained, focusing on building stamina in the exact systems showing fatigue patterns.
Beyond Concussion: Universal Performance Principles
While this case involved head trauma, the principles apply broadly to anyone experiencing:
- Afternoon energy crashes
- Difficulty sustaining focus under pressure
- Executive function fatigue in demanding environments
- Processing speed issues with high cognitive loads
The key insight: high-level performance often masks underlying circuit inefficiencies that only become apparent under sustained cognitive load.
The Neurofeedback Advantage
Traditional cognitive assessments might miss these patterns entirely. A standard neuropsychological test could show "normal" results while missing the circuit-specific fatigue patterns revealed through extended performance monitoring combined with brain mapping.
"People are weird," Hill emphasized. "By itself we don't really care about some arbitrary metric—it's always about the context. Does it serve your goals or is something in the way?"
This personalized approach—combining performance data with brain physiology—allows for targeted interventions that address root causes rather than just symptoms.
Practical Applications
For athletes, executives, or anyone operating at high cognitive demands, this analysis suggests several key strategies:
Monitor Fatigue Patterns: Pay attention to when specific cognitive abilities (not just energy) start declining throughout the day.
Target Circuit Training: Rather than general "brain training," focus on specific neural circuits showing dysfunction—in this case, prefrontal inhibitory control and alpha frequency optimization.
Expect Compensation: High performers often develop workarounds that mask underlying inefficiencies until they're pushed to sustained limits.
Address Root Causes: Brain fog, name retrieval issues, and afternoon crashes may represent treatable circuit dysfunction rather than inevitable consequences of aging or stress.
The combination of objective brain mapping with performance testing provides a roadmap for optimization that goes far beyond general wellness advice—it targets the specific neural mechanisms limiting peak performance.
For more detailed information about SMR neurofeedback protocols and thalamocortical training, see our comprehensive guide: SMR Neurofeedback: The Calm-Alert Brainwave That Trains Sleep, Focus, and Self-Control