I have always been fascinated by the workings of the human brain. Not psychology or philosophy, really, but more on the actual neurological processes and 'physical' workings, though the subjects have countless connections. So, I will devote today's post to describing the human brain. I will recommend
this book, though I have read only the pages provided freely by Amazon.com.
Your brain contains around 100 billion neurons, which send information. These neurons are most densely concentrated in the outer layer of the brain, which is wrinkled in order to allow more surface area. This additional surface area is important because the brain has acute needs; the more places that chemicals can be fed into the brain, the more that can be crammed into that area. These neurons are linked by synapses – millions of billions of synapses, in fact. Thus, each neuron is only a few degrees of separation from any other (any neuron can send data to any other by routing it through maybe two or three other neurons, if not directly). These links are strengthened by repetition – indeed, many links are formed when a task is done repeatedly and the brain can make this process more efficient by forming new, more direct synapses.
Many of the brain's neurons specialize in processing of sensory information – sight, sound, taste, ect. – but the processors of different senses have linked together. Thus, taste and smell are very closely linked, while sounds can cause you to 'feel' something that actually does not exist – a Bose speaker demonstration capitalizes on this to proclaim the quality of their most expensive surround-sound system (in this case, you hear a thunderstorm and rain, and see flashes of lightning on a screen, and you start to 'feel' the moisture that would be in the air during a real storm). These links are supplemented by memory, which will fill in gaps to supplement information that is outside the norm (like hearing and seeing a storm yet not getting wet). This also allows you to 'feel' in dreams just as much as you can 'see' and 'hear' in dreams, despite what popular myths about pinching oneself claim. All humans dream, whether they know it or not – memory of dreams can fade very quickly, unless one realizes during the dream that they are dreaming (this is called lucid dreaming), in which case the memory may be preserved in a way more like memories from waking life.
The reason that humans, and many other animals, dream is not well understood – I believe animals other than humans dream because my dog occasionally kicks or whimpers in his sleep. When asked "why", the most common answer is about REM (Rapid Eye Movement, a stage of sleep that lasts only a few minutes at first and occurs several times during the night – the later occurrences last much longer –, during which the eyes move rapidly), the period during which most or all dreams are believed to occur. REM, however, has far more to do with
when than
why. It is during this REM period that parts of the brain activate as though the person were awake – some parts of the brain may even be more active than they are in the awake person.
Humans may dream, as Freud suggested, to vent basic impulses of the human subconscious, but this implies that only the seriously troubled dream (as they would have the strongest urge to vent), which is far from true. Another leading theory is that dreams allow a person to practice a reaction to threats. This would explain reoccurring dreams of war veterans, as such dreams may be an attempt to give the veteran a better chance of surviving a similar event in the future. This argument also is supported by the fact that it may be an evolutionary trait – more practice against threats would surely allow a person to fare better. However, this explanation also leaves much to be desired. Another theory is that chemicals produced during the dreaming process, but produced infrequently during the rest of sleep, are important to maintaining the body – such as maintaining body temperature.
It is generally believed that much of the subject matter of dreams in illogical and incoherent. Nearly all dreams last minutes (between a few and as many as 40), even though they may seem to go on for hours. The brain may draw from memories in attempts to put the incoherent subject matter into a rational context, which would explain how a dream can seem to last so long.
Back to the neurons. Your brain likes to make things efficient. Thus, it will delete memories, or reuse one memory for several similar events – this is why you can always remember having turkey at Thanksgiving but have no idea what you talked about at the table, or who you sat next to, unless everyone has the same seat every year. Additionally, there is a 'memory curve' – people tend to forget the most after a few days, and forget less per day over the following weeks and months. Repetition or reinforcement of the memory over the first few days can greatly increase its completeness and longevity – this is why cramming the night before an exam has little effect compared to a week or more of studying. Occasionally, the brain will alter a memory, and the person will be unaware of the inaccuracy, and it can sometimes create false memories. One particular test of the later included having participants (who thought they auditioned for a commercial) asked if they had met Bugs Bunny when visiting Disney World as a kid. The participants were split into groups, one acted in a commercial with no mention of Bugs, one was in a commercial with a cardboard cutout of the bunny, one read a script that mentioned the 'waskally wabbit', and one had both the cutout and the script mention. About one third of the Bugs-script readers said they remember meeting Bugs at Disney World, or were certain that they had met him; while about 8% of the no-Bugs or cutout-only group claimed to have met Mr. Wabbit. One problem: Bugs is a Warner Bros. character, and would never be seen in Disney World.
That's the post for today. Perhaps, further commentary on the subject will come soon.