Home > Uncategorized > Some musings on cognitive computing….

Some musings on cognitive computing….

Electronic vs Biological memory.

 

Memory is a scarce resource, in both electronic and biological forms. In our lives we perceive much more information through our senses than we could ever hope to remember. It is like trying to store the World Wide Web on a single computer.

 

Our brains prioritize information, providing quick access to important information, slower access to less important information, and we simply forget what unimportant details, such as what you had to eat for lunch two months ago. In a digital sense, if we were to store the Internet on a single computer, we couldn’t fit it all there, but we would start with the most useful and informative websites, and leave out websites such as “What I think of my neighbours cat” by Joe Nobody in Alabama.

 

Furthermore, our brains will generalize information, in order to save neuron-space. For instance, when you think of a horse, you would have a general image in your head, complete with head, tail, four legs etc. One can imagine the horse with or without a saddle, or in a variety of colours, but these are optional attributes. This is in stark comparison to how a computer would store images of horses, computers would have an index of a Grey horse, brown horse, Shetland pony etc., where a human would only have one image, but it would be general and accurate enough so that it is possible to instantly recognise a horse when seen.

 

Computers compress data too, in one of two ways, lossless or lossy. Lossless compression uses statistical analysis to reduce data entropy. A little similar to seeing six horses in a field, and remembering the number “6” and associating it with a horse, rather than remembering the image of the six horses. Lossy compression is where less visible, or less audible information is removed from either an image or sound. Digitally, this is performed using a mathematical harmonic analysis (DCT), to reduce low-amplitude harmonics from audio or images. Humans do this too, – You may know what a horse looks like, but couldn’t tell whether they have dimples on their noses or not.

 

One of the more interesting parts of human memory, is how information is prioritized. It happens without conscious intervention, but the process can be controlled with conscious thought. Most English-speaking people can remember maybe 20,000 english words, and their meanings, But only a few hundred people’s faces and names. This is because symbolic data takes less space than images – quite analogous to the digital world, where a small image could be 100,000 bytes in size, and a word consumes only a few bytes.

 

Regardless of neuron-space consumption, all information is prioritized in the same way. You might find it just as difficult to remember your aunt’s phone number, than what the latest mobile phone looks like. Even though, a phone number should only be a group of 12 numbers. What might hold a clue to this, is the linkage of information within our brains. When one thinks of an English word, we immediately know, how to spell it, what it means, how it sounds, and for some verbs or nouns, an associated image.

 

From a digital perspective, this approach would be counter-intuitive, since, it would create overhead linking each word to its associated imagery. However, the benefit afforded through this method comes down to how our brains generalize information. When visualizing a complex scene, we can isolate elements within the scene that are stored elsewhere, and therefore do not need to be re-stored. For instance, a bathroom may have a shower, towels, soap, shampoo etc, but a swimming pool washroom may also have similar elements. The human mind can associate the discrete elements with pre-stored generalized objects, thus saving memory. It also re-enforces the importance of the various elements, because if you forget something that is common to one or more contexts, then the context(s) are incomplete.

 

Some search engines are beginning to use this technique too. If a web page is linked to by many other pages, it is deemed important, and thus prioritized. Information that is not linked is deemed less important. For instance, there are 416,000 links to Amazon.com and none to MyCat.com, thus a search on “book on cats” will show a result from Amazon.com, not MyCat.com.

 

The human brain has evolved from the hunter gatherer days, when it was important to remember and distinguish between poisonous berries, and tasty fruit. In those days there would be little need to remember a set of thirteen digit numbers in order to speak to family members. Thus, our image generalization and storage mechanism is highly evolved, and, although it is simple for our brains to associate a symbolic representation to one of these stored generalised images, our brains find it very difficult to prioritize symbolic information which is not associated with an image, sound, or smell.

 

Since a phone number is devoid of image, sound, smell, tactile information and so forth, it is weekly linked within our brains, and thus if we do not make a conscious effort to remember it, or refer to it on a daily basis, it will be de-prioritized, and eventually over-written with other information.

 

Human cache memory is a slightly different issue. This is where rapid-access information is stored temporarily. In this memory, One can remember a phone number long enough to dial it, but not if you are distracted, by another activity, such as talking or writing. This cache memory is investigated in “Conversations with Neil’s brain”, where a patient with a damaged temporal lobe, retained the use of his cache memory, and could recall long-term memories but could no longer store new memories.

 

Advertisements
Categories: Uncategorized
  1. No comments yet.
  1. No trackbacks yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: