How does HTM recognize thousands of objects of the real world?

[bowen]

@jhawkins

The TBT does not propose each column learns models of every possible object. We explicitly state this in the frameworks paper. What we say is that there are many models of each object. For any object there might be multiple models based on visual input, multiple models based on somatic input, and multiple models based on auditory input. Each model is different because it is based on different inputs. But if different columns in the neocortex are modeling the same object, then long range connections between them make sense.

@Paul_Lamb

Firstly, I can’t speak for Numenta, but I do not take the quotes you have highlighted to imply that they believe there is no classical hierarchy present in the cortex. On the contrary, there are many examples from recent talks where Jeff and others have called out specifically that they are not saying classical hierarchies do not exist in the brain, but that many of the connections observed in the cortex do not fit neatly into this classical model. These anomalous connections make sense when taken from the perspective of a mechanism for voting.

Second, you are assuming that all three of the columns in your example are representing exactly the same semantics of the object. In reality, this would never be the case. You might be able to argue similarities between different fingers, for example, but this same system is modelling objects from vision, audition, taste, emotional state, needs. All of these models are voting on what is being sensed. I simple “cup” can become something far more complex when combined with being tired, sense of security from the warmth, social aspects of chatting with colleagues over coffee, etc.

These exactly solve my puzzles. Thank you very much!

There is another question, how does neocortical represent hierachical features? As Browne said:

@Bitking

A given letter may only be one of a few hundred glyphs. Combine these into grouping and you can represent a much larger set of objects.

Does this means that some columns’ inputs derive other columns’ outputs?