Comment by trombonechamp | Hacker News Reader

Comment by trombonechamp | Hacker News Reader

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My PhD was (partially) on this. The inability to inhibit actions when facts change on a short timescale (sub-second) is thought to be biological. According to the most widely accepted theory, think of the brain as having a slow system and a fast system. The slow system is good for complex processing, but of course it is slow. There is also a fast system for quickly responding to things. If something changes while the slow system is working, usually the fast system is pretty good at stopping the slow system from acting, allowing the brain time to incorporate the new information into its plans. But if you are already planning on doing something and getting ready to do it, there is a limit to how quickly the fast system can interrupt the slow system. It tends to be on the order of 1/10 to 1/5 of a second.

On a longer timescale (minutes to days), there is a clinical symptom called "perseveration" whereby people can't let go of previously held beliefs in the face of changing information. It is common in, e.g., patients with schizophrenia.

I was once using an old but high end HP DC power supply to test a repaired 12V microcontroller circuit that someone else mysteriously blew up "with a spark". Before I hooked up the fraying and grimy alligator clips coming off the supply, I had the thought to check the actual voltage with a multimeter, in case the supply was out of calibration. Before I consciously perceived what my multimeter read, my hands rapidly dropped the frayed wires. I connected up the multimeter again, and it read 120V! Someone had mistakenly missed a decimal point, and the archaic LED display made it look like 12.0V.

A low level part of my brain definitely took over control of my hands, based on interpretation of visual signals. That was 6 years ago and I still think about it every few days.

https://en.wikipedia.org/wiki/Perseveration

oh - the highly repetitive response common in autism.

Are there gradients of perseveration? This is absolutely fascinating - a brain based answer to why people do many behaviours - from sitting in the corner mumbling one word over and over, to various forms of self sabotage ("always picking the wrong man")

(And I might say heartening - as the father of an ASD child, it can seem hopeless, but just being armed with some knowledge of where the behaviours come from might allow some hope)

There are ways we can measure perseveration in the lab, and so yes, it can be higher or lower in different people. If you want to look into it more, a popular way to measure it is the Wisconsin Card Sort Test (WCST), or the version for children, the Dimension Change Card Sort task (DCCS). However, like all cognitive tests, these are imperfect measurements of perseveration - they may be indicators of higher or lower perseveration, but scores may be influenced by a multitude of other factors as well. Likewise, there may be aspects of perseveration not captured by these tests - like you mention, there are different ways that one can be perseverative, and one single number can't ever represent the complexity of human behavior.

thank you

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