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Sample size: 26. Confounding variable: all older people. Also the exercisers did not perform significantly better in the memory test! They only had higher activ

Sample size: 26. Confounding variable: all older people. Also the exercisers did not perform significantly better in the memory test! They only had higher activation in the regions of the brain associated with memory! Really a garbage conclusion from the actual article

yjftsjthsd-h 8y ago
... Isn't increased brain activity a sign of worse performance? Because when your brain is actually operating efficiently, it doesn't need to light up very many neurons to do what it needs to do.
- ip26 8y ago
  On the other hand, forgetfulness and memory loss is associated with simply losing access to the neurons. If your memory bus was faulty, DRAM would be pretty quiet.
- antris 8y ago
  This is literally what is said in TFA: > Less activity suggests that the brain had become more efficient at semantic-memory processing as a result of the exercise, requiring fewer resources to access the memories.
  - maxerickson 8y ago
    It's clear in the paper that their result is the other way around, exercise was correlated with higher activation intensity. https://www.cambridge.org/core/services/aop-cambridge-core/content/view/07DE0F919CEFBCE268A95474DFA1BC47/S1355617719000171a.pdf/semantic_memory_activation_after_acute_exercise_in_healthy_older_adults.pdf https://www.cambridge.org/core/services/aop-cambridge-core/c... The activation intensity isn't necessarily a measure of efficiency anyway. There wasn't a difference in blood flow, so energy use would have been similar.
- jfoutz 8y ago
  Not hard to imagine the degenerate case though. Hey, remember X? Nope. Checking more things before returning the negative result might be better.
maxerickson 8y ago
The memory test was designed not to measure performance (the names presented were preselected so that performance with each of them exceeded 90%). For a real effect, a sample size of 26 is going to show it just fine.
- mruts 8y ago
  Depends on the effect size.
sonnyblarney 8y ago
Surely. But I know that this is true for me. I can tell at the end of the day whether I worked out or not just by how I feel. Without workouts I feel foggy, slow, unmotivated. Doing cardio I feel 25. Same for others so I hope they continue this research.

yjftsjthsd-h 8y ago

... Isn't increased brain activity a sign of worse performance? Because when your brain is actually operating efficiently, it doesn't need to light up very many neurons to do what it needs to do.

ip26 8y ago
On the other hand, forgetfulness and memory loss is associated with simply losing access to the neurons. If your memory bus was faulty, DRAM would be pretty quiet.
antris 8y ago
This is literally what is said in TFA: > Less activity suggests that the brain had become more efficient at semantic-memory processing as a result of the exercise, requiring fewer resources to access the memories.
- maxerickson 8y ago
  It's clear in the paper that their result is the other way around, exercise was correlated with higher activation intensity. https://www.cambridge.org/core/services/aop-cambridge-core/content/view/07DE0F919CEFBCE268A95474DFA1BC47/S1355617719000171a.pdf/semantic_memory_activation_after_acute_exercise_in_healthy_older_adults.pdf https://www.cambridge.org/core/services/aop-cambridge-core/c... The activation intensity isn't necessarily a measure of efficiency anyway. There wasn't a difference in blood flow, so energy use would have been similar.
jfoutz 8y ago
Not hard to imagine the degenerate case though. Hey, remember X? Nope. Checking more things before returning the negative result might be better.

maxerickson 8y ago

The memory test was designed not to measure performance (the names presented were preselected so that performance with each of them exceeded 90%). For a real effect, a sample size of 26 is going to show it just fine.

mruts 8y ago
Depends on the effect size.

sonnyblarney 8y ago

Surely. But I know that this is true for me. I can tell at the end of the day whether I worked out or not just by how I feel. Without workouts I feel foggy, slow, unmotivated. Doing cardio I feel 25. Same for others so I hope they continue this research.