One of the core open questions in neuroscience is: How is a piece of information represented and memories stored inside human brains? This is a question I’ve been casually pondering over for a while. I strongly suspect that each individual has a different representation of ideas in their brain, and these differences explain a numer of psychological phenomena we see in daily life. This is a stream of consciousness post, with no links to academic research, mainly so I can catalog my thinking and build upon it later, and use this piece as a launching piece to discover futher refinements and corrections from friends that know more about these topics.

  • When we are very young, how do we understand or ascribe meaning to a new object or concept? Intuitively, it feels that the only way to do this would be to represent the new concept in terms of things that we already know. If this is true, then as we grow older and encounter new objects, people, and concepts, we must be representing them in terms of the things we already know, some fundamental, and some complex. My mental model of this is kind of like a continuously evolving Huffman code, where we are constantly representing completely new information in terms of older concepts, and over time reorganizing the set of connnects to compress the number of links.

  • I think for the above reason, different individuals can have very different representations of a concept in their minds. Our mental representation networks start diverging the moment we are born (or perhaps even before that, if genetics play a role) because we encounter new ideas in a different order, and not all of use encounter the same set of ideas and experiences. Two people presented with the same outward stimulus, like a piece of art, are more likely than not to interpret it in completely different ways.

  • If we buy the above, then a natural question that arises is: what is the very first concept that we come pre-loaded with? The master concept that we can then use to build upon? And how complex is that initial concept? I don’t have answers. But my guess would be that that first concept in terms of which we evaluate new information is: survival. Is this new thing could to aid my survival, or could it be a threat to my existince?

  • Why is it that when we experience a food or a song or movie that we had last experienced as a child, it often brings forth a warm nostalgic deeply meaningful wave? Many people have commented on this. The common answer is that the song or food evokes memories of that period of childhood, and assuming it was a pleasant childhood, it evokes a positive memory. But the question is why does that song/food evoke memory of other aspects of our life from that period of time? This suggests that our memories are somehow stored in a manner such that recalling an event from the past also triggers memories of other events that occured around the same time. As if the two events were stored adjacent in memory space in the brain.

  • It is generally agreed that as we get older, it is hard to make new deep friendships. I think the reason behind is that to make deep friendships, we need others with similar a representation space – so that things that we find meaningful are also meaningful to our friends. With age, representation space diverges, and what is meaningful to one is not meaningful to another. Occaisionally, we find a person with a similar representation space as us, and often we find that this person has had similar life experiences to some degree – maybe they also grew up in a similar town, or they experienced a similar challenge at a similar stage of life.

  • I think this is also why as we get older, we find that something we find deep and meaningful is not necessarily meaningful to others in our social circle. We might find a story, or a play or a song deeply moving while another person might not see what we see.

  • Apparently there are communities that do not have words for right and left in their language. One example is the Guugu Yimithirr people of northern Australia. Instead of saying something like “Could you please pass me the fork to the left of your plate” they might say something like “please pass me the fork to the northeast of your plate”. Another such community is the Kuuk Thaayorre also of Australia. when asked to arrange pictures showing time progression (e.g. aging), English speakers typically arrange left → right while Kuuk Thaayorre speakers arrange east → west regardless of which direction they themselves are facing. Does this mean that the people of these communities are working extra hard to constantly keep track of their orientation? I find this unlikely. My guess is that their brains are representing their visual input in a different way.

EDITS:

Emily Finn of Dartmouth has been study something very very close to the above.

I think the ideas above explain a few more things:

Two people presented with the same information or experience can interpret the experience completely differently. They can also pay attention to very different components of the experience.