Jet Lag

            I’ve always found jet lag to be an interesting word, which is the interruption of circadian rhythms caused by the changing of time zones. To understand things a bit further I will explain what is the circadian rhythm. The circadian rhythm is our biological clock, telling us when to go to sleep and wake up based on light, meals, temperatures and much more.

            When we change time zones, we either lose or gain sleep, which affects us, causing sleepiness during the day or sleeplessness during the night; it also may cause depression or impaired concentration. Time zone changes are not always hard, for example going to the west is a much easier change than going to the east, because when we go west gives us more time to stay awake and wake up late which is easier to adjust to, while going to the east means we are forced to go to sleep earlier and wake up earlier, because of the lost time. It is more difficult to go to sleep earlier than the body’s accustomed time.

            Getting used to time zone changes can be very difficult and place a lot of strain in our bodies, and the hormone cortisol is elevated which high levels of it can damage the hippocampus, the area important for memory, here is an article that shows the symptoms of jet lag. Studies have been made where flight attendants who worked for 5 years making lots of time zone changes, had their hippocampus looked at. As a result it was found that they have smaller hippocampus than average showing some memory impairments. Here is a video on how to avoid jet lag.

Choosing a Partner

            Finding a partner is not that simple. As humans we have a few needs the three most basic ones for survival are, eating, drinking, and the passing of our genes. When we look for romantic partners we tend to look at some things like physical attractiveness, health, intelligence, and honesty.

There are several factors that are looked at but women look at more of them rather than men, one big thing in picking, that’s mainly due to maternal leave in which the mother can not go out to get things and provide for her child while the man can, so women are most likely to chose a man that will stay around and has the income to support her and the child, she doesn’t want someone that will just show interest at the time and then leave her. Another factor looked at mostly by women is smell, if the men has a different smell then her brother or a family member she is most likely to go for them, because that shows that they both have different immune systems, and they’re offspring’s can benefit from it by having a more diverse immune system, as the opposite is true if your smells are very similar.

Some things are more important for men then are for women. For example, men look for younger women, because they are more fertile than older ones, and they mostly prefer looks, health, and intelligence, because men know that they that they will be the ones to provide, they don’t typically look at status on the business world.

Choosing a partner goes beyond just genetics, if not we would end up miserable because a person might have good genetics but may not suit us emotionally wise, so I leave you with this article on choosing a mate: what we really want, and a video on how we chose based on attractiveness levels.

Pheromones

I’ve always found pheromones to be an interesting topic, pheromones are chemicals released by an animal that affects the behaviors of a member in the same species, pheromones are picked up by vomeronasal organ (VNO) which is separate from the olfactory receptors but near them. VNO respond constantly to pheromones, while olfactory receptors get used to the smell after a while so you don’t seem to notice it. Compared to other species, we humans have very little VNO’s, because we hardly use them so we don’t need as many receptors as other species do.

Pheromones effects on behavior are at the unconscious level, in other words most people can’t smell pheromones but yet they react to it, pheromones even take a role in picking a partner, because the immune system affects our pheromones, people can find a more suited partner, genetically, that way the off springs have a better immune system hence higher chances of surviving according to this article.

Pheromones seem to affect more females than males, exposure of chemical from the opposite sex seemed to have some effects on the subjects, like the changing of skin temperature, other autonomic responses, and increased activity on the hypothalamus. Some studies have found that when females are near ovulation, it increases the release of testosterone on males near by and that the smell of a man causes a release in cortisol for women, other studies have shown that when women are near each other, example they live together, they get on the same menstruating cycle, if they are not on contraceptives.

Amnesia

I found amnesia to be very interesting. Amnesia is the loss of memory, usually from hippocampal damage and some times from surrounding areas of the medial temporal lobe. The two main forms of amnesia are anterograde amnesia and retrograde amnesia. Anterograde amnesia is the inability to form new memories after the brain damage; retrograde amnesia is the inability to recall memories before the brain damage. Here is an article that shows other forms of amnesia like Korsakoff’s amnesia and many more.

One of the most interesting things about amnesia is that short-term memory or better known as working memory, which is memory we use at the time, is not affected but long-term memory is. You can take a patient with amnesia, have them memorize a few numbers, and after a while without other distractions you can ask them to recall the numbers and they will, but if you give them some other task to complete, they will not remember the numbers that they were given at the beginning, this probably happens because when the patient has to start thinking about something else the memory of the numbers has to be stored in long-term memory, but since it is not working, it doesn’t happen. Another interesting thing about amnesia is that when patients with it see them selves on a picture they assume it is not them and that the person standing there is someone else, while when they look in the mirror the recognize them selves and are not shocked by changes from age, mostly because we know when we see a reflection in front of us that it is us standing there.

Severed Corpus Callosum

This week’s main topic of interest was the severing of the corpus callosum, because I find it very interesting that we can damage the bridge to the brain’s hemispheres and live a normal life.

            The severing of the corpus callosum became famous for treating epilepsy, which are continuous episodes of extreme synchronized neural activity, the activity usually bounces back and forth from hemisphere to hemisphere, which keeps it going, therefore severing the corpus callosum keeps the excessive neural activity from damaging the other side of the brain, and it stops much quicker than it did before.

            People with a severed corpus callosum are referred to as split-brain people, these people don’t have many problems from the severing of the corpus callosum, which you think they would from damage to the brain. At first split-brain people might have trouble adjusting to their new life style, because their brain needs to get used to the lack of communication through its main source the corpus callosum, but that isn’t the only connection between the two hemispheres, there are very small ones along the two hemispheres that help out after the corpus callosum is severed, although not as powerful they are somewhat affective.

            Some of the problems that come with the severing of the corpus callosum is how the hemispheres perceive things. Our brain works in mysterious ways, the left hemisphere controls the right side of the body and the right hemisphere controls the left side of the body. Because of how the brain perceive things sometimes even if something is seen by the right hemisphere that would be on the left visual field, we can talk about it even though we might be able to point it out, and that is because the part of the brain that works with language is on the left hemisphere, while we might notice emotions a lot better on something we see in our opposite visual field, since the right hemisphere works with emotions. Here is a video of a man named Joe with a severed corpus callosum and how his brain works in different procedures.