The engine
The brain, and how the world gets into it
The brain takes in the world through the senses, compares it with what it has already seen, assigns emotional value in milliseconds and returns an action. That journey is what decides whether your interface is easy or tiring.
The same brain
The technology you build with changes generation every few years. The device of the person who will use it is three hundred thousand years old and has never had an update.
It is the only part of the project that does not change. A flow designed for the limit of working memoryThe mental space where the person holds what they are using right now. It holds about four things, and they fade in seconds if they are not used.See it in Memory →See in the glossary → will keep working after the framework has been rewritten three times, because the limit was nobody’s decision and has no version.
That is where this site’s name comes from. Same Brain never meant that the brain explains everything. It means that it is the same in everyone, and that the difference between two people lies in what goes into it.
Senses and attention
Every sense evolved to filter the world with energy efficiency, not to cope with the digital flood. Knowing where each channel saturates is what keeps you from asking the body for what it does not deliver.
5 parts
- Vision A third of the cortex, and one conscious focus at a time.
- Hearing Several sounds arrive at the same time; only one becomes listening.
- Touch and proprioception The hand that operates your interface is, in the brain, bigger than the entire back.
- Smell and taste The only sense with a direct shortcut to emotion, and the one with the lowest bandwidth of all.
- Vestibular system The sensor that makes you sick in the car is never switched off.
Memory
Memory is not a warehouse: it is a process. What the interface asks the user to hold competes for room in a system that keeps about four items and drops most of what came in within little more than a day.
5 parts
- How a memory forms Where a memory passes through, from attention to the trace that stays.
- Sensory memory A quarter of a second of image, about three of sound, before any awareness.
- Working memory About four items fit, and your form competes with the rest of life.
- Spatial memory Why moving a button costs more than it seems.
- Medium- and long-term memory 70% of what the person learned today is gone in 24 hours.
Emotion
The emotional appraisal of a screen arrives ahead of conscious judgement — in milliseconds, through fast pathways the amygdala helps compose. There is no emotional brain separate from a rational one; there are pathways at different speeds, and the fast one has less of an advantage than the popular accounts sell.
4 parts
- Three levels, one amygdala Visceral, behavioural and reflective. The first arrives before the other two.
- Valence and arousal Two measures account for any reaction: how much it pleases and how much it activates.
- Emotional memory What stirs emotion stays; the rest competes with that.
- Prefrontal regulation The brake arrives after the fright, and it’s what decides whether the person clicks.
The social mind
The social circuitry was calibrated for small groups. The most cited estimate is 150 people, and it does not hold up when you check it. Digital networks did not change the scale of the circuitry; they only started demanding that it process thousands.
3 parts
- Dunbar’s number About 150 people, says the most cited estimate. The scale hasn’t changed; the networks just started ignoring it.
- Empathy and alterity Two empathies, one fast and one slow. The interface only reaches the slow one.
- Social networks and false proximity False proximity: social software running outside the scale it was made for.