Podcast Summary: That Neuroscience Guy
Episode: The Neuroscience of Middle Age
Host: Olav Krigolson
Date: July 24, 2025
Overview
In this special episode, Olav Krigolson explores the often-overlooked topic of how the brain changes during middle age. Drawing from both research and personal experience—on the eve of his own 55th birthday—he unpacks the structural, cellular, and functional shifts that occur between roughly ages 30 and 60. The episode clarifies what is considered a normal part of aging, how it differs from pathological changes, and emphasizes the enduring value of experience.
Key Discussion Points & Insights
1. Research Focus Biases and the Age Gap
- Most neuroscience studies focus on ages 18–25 due to university student participant pools.
- Young and elderly populations receive some attention, but the 30–60 age range is "neglected."
- Host claims, “What about the 30 to 55, 60 crowd?... I thought I’d talk about the changes that go on the brain in my age group.” (01:50)
2. Defining Middle Age
- Middle age typically falls between ages 45 and 65, though definitions vary.
- Krigolson optimistically cites this range, aligning with his own age: “I’m 55, so it puts me in the middle of middle age.” (02:40)
3. Normal Brain Changes in Middle Age
a. Structural Changes (03:00–06:00)
- Brain volume decreases—most noticeably in the prefrontal cortex (executive functions) and hippocampus (memory).
“From the time you’re about their age, you know, in your early 20s, your brain’s dying. You start to lose 20 to 25,000 neurons a day, and there’s not much you can do to slow that.” (03:10)
- Thinning cortex: Especially in the frontal and temporal lobes.
- Decline in white matter: Affects communication speed between different brain regions.
“Literally you might feel like you’re thinking a bit more slowly.” (05:30)
- Ventricles (fluid-filled spaces) enlarge to compensate for lost tissue (not in itself harmful).
b. Cellular & Molecular Changes (06:00–08:30)
- Reduced neurogenesis: New neuron formation in the hippocampus slows but does not stop.
- Loss of synapses: Fewer new connections means learning becomes slower and less efficient.
“When we learn, we form new connections. When we’re young… you can learn quickly... you can still learn right? Until you die. It just happens at a slower rate...” (07:30)
- Reduction in neurotransmitters: Less dopamine, acetylcholine, serotonin, etc., affecting mood, motivation, and cognition.
c. Functional Changes (08:30–12:00)
- Slower processing speed: Reaction and information processing times increase.
“Probably the biggest one is… there’s slower overall processing speed, all right. Due to the decreases in neural transmission rates, it’s just slower to process things.” (08:40)
- Decline in working memory and episodic memory: Harder to juggle information and recall specific events.
- Reduced executive function: Planning, multitasking, and decision making become more challenging.
“Our ability to plan things is, is impaired. Our decision making is impaired. Our multitasking becomes more challenging.” (10:40)
- Compensation through bilateral brain activity: The brain utilizes both hemispheres more to offset declines, debunking "left brain vs. right brain" myths.
“What happens when we’re older is we do rely more on the right side to help the left and the left side to help the right... this is literally just a compensation...” (11:45)
4. Normal vs. Pathological Aging (12:00–14:00)
- It’s normal for cognitive decline to occur as long as it does not impair daily life.
“If these changes don’t interfere with your daily life, you’re okay.” (12:40)
- Pathological aging (e.g., dementia, mild cognitive impairment) begins when decline is severe enough to affect daily functioning.
“At that point, that’s pathological aging. And that’s probably where you want to, you know, speak to your doctor.” (13:25)
5. Role of Experience
- Experience becomes a key asset in middle age, offsetting some deficits in executive function:
“...you might still, you’re probably still better at making decisions because of experience.” (11:20)
Notable Quotes & Memorable Moments
- “Your brain is slowly dying as a result of that. In middle age, your brain volume decreases…” (03:15)
- “Yes, his [my son’s] hand, eye coordination is a bit faster, but he’s literally processing the information in the game at a faster speed than I am, which gives him an advantage.” (09:10)
- “You can’t replace experience.” (10:55)
- “It’s normal to be a bit forgetful. We’re forgetful when we’re young… As we get older... it’s becoming a little bit more common. But if it’s not interfering with your daily life… that’s just normal aging.” (12:45)
- “The whole value assessment process is based largely on experience.” (11:15)
- “When we’re older is we do rely more on the right side to help the left and the left side to help the right.” (11:45)
Timestamps for Important Segments
- 00:00–02:40: Introduction & motivation for the topic
- 02:40–03:00: Defining “middle age”
- 03:00–06:00: Structural brain changes after age 30
- 06:00–08:30: Cellular and molecular changes in middle age
- 08:30–12:00: Functional changes—cognition, memory, executive function, compensation strategies
- 12:00–14:00: Normal vs. pathological aging; importance of monitoring for impairment
Tone & Style
Krigolson’s style is conversational, self-deprecating, and relatable—often using personal or family anecdotes to illustrate concepts, as when comparing his own cognitive speed to his son’s during video games. He champions scientific accuracy but brings warmth and a touch of humor to reassure listeners about the normalcy of change in middle age.
Conclusion
This episode demystifies the neuroscience behind what happens to the brain between ages 30 and 60. While some cognitive decline is inevitable due to structural and chemical changes, these shifts are both expected and manageable—especially when balanced by life experience. Pathological declines are distinguished by their impact on daily life, serving as a practical benchmark for concern.
For more detailed explorations, listeners are encouraged to check past episodes on decision making, memory, and hemispheric specialization as referenced by the host.