Perceived Age | Surya Dan
#9.11.25: Wait, so does dopamine speed up or slow down time?
- I thought the premise was that you want to increase the amount of dopamine your brain emits by increasing novelty. This didn't make sense given the adage "time flies when you're having fun."
- The essay doesn't properly distinguish between the two different types of "time": time as you experience it and time as you remember it.
- Prospective time perception (in the moment) is governed by dopamine clock speed. High dopamine → faster clock → time feels like it’s flying.
- Retrospective time perception (in memory) is governed by novelty and memory encoding. More novelty → denser memories → stretch feels longer in hindsight.
Our internal clock system, predominantly dopaminergic, and our memory, which relies on acetylcholine neurotransmission, work together to shape our perception of time. A 2004 study showed that rats can estimate time intervals up to 40 seconds even without their cerebral cortex, indicating that time estimation is a subcortical process rather than a receptor like smell and touch. In humans, stimulants that boost dopamine function speed up the perception of time, while antipsychotic drugs or feelings of sadness and depression, which block dopamine receptors, have the opposite effect. On the other hand, novelty-induced time elongates our perception of time, while mundane repetition, like a dull office job, traps us in the illusion that time is shrinking.
Related:
- “Doing as much as you can every day is a form of life extension.” (Principles )
Life is Short
A study asked different age groups to mentally count 120 seconds. People under 30 averaged 115 seconds; those over 50 just 87. That's a 24% reduction in perceived time. This shift in perception isn't just random; it’s rooted in the complex interplay of our brain’s neurotransmitters, primarily dopamine.
Dopamine plays a significant role in how we perceive time. As we age, changes in dopamine function affect our internal clocks. When we're young, everything is new and exciting—first kiss, first job, first time living away from home. These novel experiences flood our brains with dopamine, making time feel elongated. As we age, novelty diminishes, dopamine decreases, and time seems to speed up.
Our internal clock system, predominantly dopaminergic, and our memory, which relies on acetylcholine neurotransmission, work together to shape our perception of time. A 2004 study showed that rats can estimate time intervals up to 40 seconds even without their cerebral cortex, indicating that time estimation is a subcortical process rather than a receptor like smell and touch. In humans, stimulants that boost dopamine function speed up the perception of time, while antipsychotic drugs or feelings of sadness and depression, which block dopamine receptors, have the opposite effect. On the other hand, novelty-induced time elongates our perception of time, while mundane repetition, like a dull office job, traps us in the illusion that time is shrinking.
Claudia Hammond, a psychology writer, introduces the concept of a "reminiscence bump," which occurs when we encounter novelty in the world of firsts (travel, relationships, etc.). This novelty is tied to how we form our identity, causing the brain to grasp onto details that solidify how we present ourselves to both ourselves and others.