Why is the human brain so big?

From Robert Ornstein’s The Evolution of Consciousness:

A major mystery in human evolution concerns why there is such a gigantic jump between the brains of H. habilis and H. erectus. The earlier homonid has a brain only slightly larger than an ape; the later one a cortex as large as that of modern humanity.

The change seems to be almost without justification. What could the brain possibly have been doing in H. erectus to require such size? Why be able to fly to the moon when no one has even understood how to make iron? Why have a brain able to work with microprocessors when all it was being used for was the crude hammering of the first few stone tools? Wallace contended that the human brain was overdesigned for its primitive uses and thus could not have been a product of natural selection: “Natural selection could only have endowed savage man with a brain a few degrees superior to that of an ape, whereas he actually possesses one very little inferior to that of a philosopher.” If the brain of “savages”–his term for human acestors as well as modern primitives–was oufitted with higher capacities before they could be exploited, he argued, there must then be a superior force who had a future agenda. Rationality and Aristotelian thought are so compelling, even to one of the founders of the evolutionary view, as to challenge that view.

Why? For what reason was such a large brain necessitated? Talk about an accident.

*Emphasis in quote is my own.

Our Brains: Using Layers of Consciousness to Multi-Task (An Informal Essay)

What part of our minds continue to ‘think’ once we enter sleep and begin to dream? Is it our conscious or our subconscious? In other terms, is it the part of our brains that is actively aware of our surroundings and what itself is thinking of, or is it the layer beneath that? Is it the layer which thinks and processes data that the layer on top (Active consciousness) is not aware of? I ask this because events are unfolding in my dreams which I do not actively think of during the day, but a part of me, in some sort of intuitive way, somehow ‘feels’ that I am thinking this regardless. There’s some sort of ‘acknowledgment’ or ‘validation’ to what my subconscious is processing. After I wake up from these dreams, I find myself saying ‘Wow. That was strange and uncalled for? Where did that come from? Why did I kiss her? I haven’t really been thinking about her…. or have I?’ And it’s that last part upon which I reflect. It’s that last part where I stop for a moment and contemplate, ‘I think I have… I just haven’t been realizing it.’

This is perhaps the single most important use of dreams we have today. It let’s us know what the giant information VALVE that our brains are really is thinking about. In a sense, this is the human biological version of computers’ ability to ‘multi-task.’ (This is VERY interesting because if anyone’s studied psychology, research has proven that humans are incapable of true multi-tasking thought processes. We process thoughts and carry out actions on a linear basis. One takes place after the other. Even though it SEEMS like we multi-task, we always think and act in a linear form. This is perhaps why my theory may be so appealing; because it presents a chance that our brains are in fact capable of mutli-tasking, although it may not be on the same THREAD of thought… Keep reading!) Only we retrieve the second thread of tasks a bit late; after we’re done sleeping, and if we’re lucky enough to remember it. Perhaps our multi-tasking is a bit flawed, a sort of ‘beta version’ so to speak. The bugs aren’t really worked out yet.

Think about it: we already know that our brains are valves that help us break down the infinitesimal bombardment of all this information we receive each and every day (this ‘information’ comes in the form of all the rays of the electromagnetic spectrum, all the different sounds we may be able to hear, all the different things we may be able to feel; basically, there’s a reason why we only see the ‘visible light spectrum’ and nothing else, and there’s a reason we hear the range of frequencies we hear and so on; because our brains have deemed this information to be the most pertinent to our everyday survival and, as acting as a giant valve, omitted all the other types of information. For proof or this concept, please refer to the source I mention at the end of the paragraph). It helps us sort out what we NEED to know from what’s just THERE. This has been proven through years of research on the part of psychologists and neurologists who have studied the human consciousness and its levels. (Source: “Ordinary” Consciousness: A Personal Construction; from “The Psychology of Consciousness”; Ornstein, Robert E. [published year unknown])

Anyway, using this ‘valve’ metaphor/explanation and applying it to our dreams, one reaches the conclusion that our dreams help us utilize the time spent sleeping trying to interpret what our second level of consciousness was thinking about. Metaphorically, our brains function much like these new multi-core CPU’s that are coming out for computers right now. They’re similar to dual and quad-core CPUs in the sense that each level of consciousness is another CPU capable of processing data. It’s just that it’s ‘priority level’ has been reduced by our brains as a whole because it would be inefficient to our every day life functions. Many people already use the CPU metaphor for the human brain–or if not a CPU, they simply call the brain a ‘computer’ but we all know that the ‘brain’ of a computer is the CPU anyway. Basically, to tie any loose knots here, I believe that the purpose of dreaming may be (although not in its entirety) to help coalesce the two parallel threads of processing that have been running in both or more of our brains’ ‘cores’ so that we may gain a better picture of what we really see and think about each day, and not just ‘the simple things.’

Perhaps, at one point in our evolution, our brains became very capable of contemplating things far beyond normal every day existence. A human being doesn’t REALLY need to know why the stars are out there and why they move about the sky to survive on Earth. Nevertheless, we have contemplated the heavens for over several millenia now. However, contemplating concepts of such vast magnitude such as the universe and even the inner workings of ourselves may have proven to consume too much time for us to carry out day to day functions like ‘killing the bear’ and ‘gathering berries.’ So then, as evolution is notorious for doing, our brains adopted a second level of thinking (a second ‘core’ for our already existing single core ‘CPU’, just as we humans are doing now for our computers). Then, the next step in this process was to apply the ‘valve’ function of our brains that had already been there before and allow one set of information to go to the new core while keeping another set in the existing core. The final step was to allow for the brain to continue thought into sleep (“dreaming”) so that we may ‘catch up’ with what the second core has been up to while we’ve been busy surviving and living each and everyday. However, we haven’t reached the end of this evolutionary process. The kinks aren’t all worked out yet. The system needs to be perfected, but if I’m right, it’s a REALLY COOL system. I might be onto something here guys…