Tuesday, October 18, 2011

Rationalization and Confusions Caused by High Level Generalizations and the Feedforward-Feedback Imbalance in Brain and Generalization Hierarchies

Rationalization and Confusions Caused by High Level Generalizations and the Feedforward-Feedback Imbalance in Brain and Generalization Hierarchies

Continues from Frontal Lobe Activation Patterns in Pessimistic & Optimistic Brains, and in Infant Brain Before and After Understanding of Object Permanence

1. Higher-to-Lower level feedback is less efficient than Lower-To-Higher level feed-forward generalization.

Example: Image/Object Recognition vs Image/Object Rendering, performed by humans.

Every healthy child can recognize human faces, understand emotions and react accordingly, but it's not that easy when intentions are involved - feedback/output to act over environment. Realistic drawing or painting of faces or good acting in a film require time, talent and practice.*

(*I guess I can get the critics that regarding painting/drawing it's just "precision vs scope", some autistic people are great in copying inputs. However drawing by memory and creative drawing of imaginary subjects require both scope and precision and capability to keep consistent mapping between all the levels, from the highest to the lowest.)

2. Generalization out of specifics (rich sensory input) is simpler/more efficient than specification down from generalizations ("decompression")

Generalization is selective lossy compression. Decompression requires reconstruction of the lost data, or requires that data is preserved or the knowledge how to extract it from external memory and incorporate it is kept. Here is the point of "precision vs depth", however I'll emphasize that sometimes a lot of both is needed.

Besides, I suspect depth has more severe limitations than precision for the lower levels. The cognitive hierarchy can add generalization levels at the expense of wider scope of input data and/or lower detail, but these both are problematic - if the scope is extended at the expense of detail (to keep computational complexity under control), then generalization levels will run out shortly, because there won't be meaningful details remaining. On the other hand, if the scope is extended with more modest detail lost, then learning will go computationally out of control.

We don't know where a machine can go in generalization levels with more computing power, but I think brain is very limited.

3. Higher level sensory inputs have less of impact over the cognitive hierarchy, because the feedback is less efficient than feed-forward.

That's the reason why captions "Smoking kills" or "Speeding kills" usually have no effect to make people stop smoking or stop speeding and why first-hand experience - to see with your own eyes, to hear with your own ears and to touch with your own fingers - have more dramatic effect in transmitting any message, than relayed experience of others.

Seeing your friend smoker dying of lung cancer or seeing your friend smashed in his car because he drove drunk - that's a pretty different sensory input - and not only because of your personal involvement with the sufferers.

Text is too abstract and distant - the low level physical representation of text is meaningless, it serves only to encode a higher level representation - that's where the input starts having a meaningful impact to the brain, and the message has to go down in the hierarchy to have actual impact on the behavior.

Another example is acting and film. Film as media demands providing motion pictures and rich sound - the physics of the action at the lowest level possible with a lot of details/high resolution of the input. If there's too much of a dialogue and too much of self-explanations and declarations by the characters, especially of obvious things - then brain is fed with high level generalized input, it can't activate the lower levels from the top-down, and they're idle or "bored". On the other hand if the lowest sensory input is rich, brain can induce up generalizations and engage the entire hierarchy. (Besides the effects of the balance of unpredictability etc., see Schmidhuber's works on Creativity)

4. Rationalization is playing with high-level patterns to explain lower level patterns, which the higher level cannot access, because of the fact that feedback is worse than feedforward, or because lower level patterns are unknown

Higher levels in the cognitive hierarchy are derivatives of the lower levels - the lower levels induce the higher ones, not vice verse. In a sense (a bit simplified), higher level patterns in the cognitive hierarchy are a delayed expressions of the lower level ones. However once a higher level emerges out of the stable regularities in the lower level, it starts to mess with the lower level business - adjusting lower level input, selecting data to keep attention on; adjusting coordinates, resolution, location; and the higher level does in order to maximize its own "success" - match, prediction, reward.

Higher levels usually cannot explain and trace back how they are created, what their lower level patterns are and what are the lower level drives.

Similar situation is with bad philosophy and other fields* where lower level conceptualization, patterns and input are wanted for a conceptual progress, but practitioners deny it and keep blah-blah-ing with concepts which are too high a level, too general, too unrelated to the problem they're trying to solve.

That's also one of the reason for researchers such as Boris Kazachenko and myself to suggest bottom-up approach - it allows for the maximum possible abstraction, while keeping maximum possible resolution and keeping the traces of the abstraction.

*Search the blog with "What's Wrong with Natural Language Processing

5. There are Two Reward Systems which are Messed Up

There's another issue - two reward systems run in parallel in brain. A cognitive and a physical. Cognitive system aims at maximizing predicted match of pure data, while the physical system aims at maximizing desired match - input sensations must match hardwired target sensations loaded with value - food, warmth, water, sex etc. The physical is way more primitive and crude, it relies a lot on the more primitive brain areas and on dopamine and other neurotransmitters/neuromodulators/hormones, while cognitive system is based on finer processing, even though the former participate also. Both systems interact and overlap, the physical system can override the cognitive and make it a slave - for example higher level cognition of drug addicts is a slave of the primitive need to take the drug. Generally these systems are messed up and tangled, so it's hard to trace where starts which in real behavioral record.

6. Rationalization is also explaining physical motivation with cognitive means

Ask somebody why she loves her boyfriend. She's likely to tell you "because he's smart, funny, kind, blah, blah and because he'so soooo blah!", while the real reason is much simpler - the way he makes her feel. That's why she loves him, where "to love" has also more basic meaning than the societal one - it's about quantities of neurotransmitters and about "imprinting" of addiction-cycles of generating such neurotransmitters by physical-cognitive conditioning, inter-association.

It's true that the abstract reasons do play certain role in creating the inter-associations between physical and cognitive sensations - everyone has some preferences and favorites, - however this can be reduced to:
- I love him because he's the type I wanted him to be!
- I love him, because he's my perfect match!
- He's the best match I could find so far...

This is a match between desired and input, which is the type of match of the physical reward system - apparently this selection is driven by the physical system, overriding the cognitive.

That's why I think the abstract reasons of "smart, funny..." are "rationalizations", but rationalization is not strange at all. Everybody would say "yeah, socially acceptable explanations", but that's a cheap answer.

There's one more appropriate reason for rationalization - it's the cognitive system which is asked the question (it's asked in a natural language); the highest levels in the cognitive hierarchy are ruling this area, and yes - the society has taught this higher cognitive system how it should act in such situations etc.

If you ask the question in a lower level language, the answer is different - that's her body language and her behavior when she's with her boyfriend alone, when they're kissing and making love. The answers are also in the amount of oxytocin, dopamine and other chemicals in her brain, the release of which is conditioned with the certain cognitive patterns initially generated by perceiving her beloved one.

In general, for love and attraction it's true by the definition of "emotions" that the physical reward system kicks in. One may be "just a friend" with someone because he's "smart, funny, blah-blah", but even then if one is a human being with a brain in tact (not a sociopath/psychopath), his friendship relations would be messed up with the physical reward systems - emotions, crude emission of certain chemicals and activations of primitive brain areas, which is associated/recorded/conditioned with cognitive patterns, and both are inter-twined.

Purely cognitive "friendship" is business and if it's such, it's not really a friendship.

*Higher/Lower level drives - Passionate feelings demand for "lower" drives, where "lower" in this context has different meaning than lower in the cognitive hierarchy. The meaning here is driven by evolutionary and physically "lower" brain modules, which maps to areas different than the neocortex, archicortex (hippocampus) and thalamus. However physical reward system is not in the same hierarchy as the cognitive system and the levels regarding tracing back, cognitive and physical reward systems are entangled and the physical system can manipulate and "short circuit" all levels of the cognitive hierarchy.

Continues... - On the apparent inconsistency of the goals of a system with cognitive hierarchy and More on rationalization and the confusions of the higher levels in the cognitive hierarchy.

Suggested reading:

Analysis of the meaning of a sentence, based on the knowledge base of an operational thinking machine. Reflections about the meaning and artificial intelligence - T.A. 2004





Slides on T. Arnaudov's "Teenage Theory of Universe and Mind"

(C) T. Arnaudov 2011