Assignment: Evolution and Psychological Behavior

Evolution and Psychological Behavior

     Evolutionary Psychology is the thought that as humans evolved into what they are now, there were mutations and adaptions in the gene pool. Some were helpful to the survival to the person and they passed their genes on. The unhelpful ones or the mutations died out and they were unsuccessful in passing their genes on to the next generation. In the beginning, they weren’t as adapted to the environment as we are now because of this process of natural selection.

            Instincts are behaviors that are performed without based upon prior experience. Instincts are something that all animals have, from bacteria reproducing to baby turtles drawling out of their nest and running towards the water. Because animals have them, we do too. Some examples of these instincts are the instinct to crave salts and sugars and sex. Humans evolved to crave salts and sugars because if they didn’t, they wouldn’t get enough and they would become undernourished and that trait would die out. Sex is a huge part of human instincts because of similar reasons like the salt. If human didn’t crave sex, then they wouldn’t reproduce and be successful in transferring their genes on.

            A universal trait is a trait that every single (with some exception) organism of certain species has the same trait. Determining if something is truly a universal trait is a colossal challenge. Why? Jus think of how many people you would need to collet data from to get a truly universal trait. Travelling around the world to tons of different countries would be expensive and would take lots of time. Because of this, not many behaviors have been labeled universal, and the ones that are, can be challenged because several of the scientists just decided to skip this step out of convenience; therefore labeling wrong universal traits.

Homosexuality is controversial topic and can be somewhat explained by evolution, also a controversial topic. In terms of natural selection, homosexuality should have been wiped out of the human race thousands of years ago. The humans who were homosexual wouldn’t have reproduced and been successful in passing on their genes so eventually they would be naturally selected out. Well, today 15% of the world’s population is known to be homosexual. Why? There is a theory that thousands of years ago, the human who wasn’t attracted to the opposite sex, would then stay with the children and take care of them. Because the children and the human were related, they had the same homosexual gene in them so with this interaction, the gene would show in the child and they would be homosexual. This gene may even have an evolutionary advantage because the human would then take care of children whose parents died, couldn’t take care of their kids, or had a kid who needed extra attention. Maybe. No one can prove or disprove these ideas so it remains a strong theory. 

Brain Imaging

Brain imaging Technologies

In recent years, brain imaging has become quite advanced from the previous technologies of the 1900s. These new technologies have helped science advance in cures and knowledge about the human brain. Two examples of this new technology is the fMRI; functional Magnetic Resonance Imaging, and PET; Positron Emission Tomography.

            The fMRI detects blood flow to particular parts of the brain and can provide a functional view of the human brain. This type of brain imaging is particularly useful to detect the effects of head trauma tumors, and diseases like Alzheimer’s. When patients are acting erotically or abnormally the fMRI can be used to see exactly what part of the brain is being used, or not being used, in real time. In a recent study, researches had experienced meditators and novice meditators focus on a red dot. During this time they were inside an fMRI to measure where and how much brain activity there was going on. Because they used this equipment was used instead of another type of imaging, the scientists could easily determine that long periods of time training meditation can affect the brain.  Although this machine is considerably useful, there are also some limitations to this technology.  The most common problem is claustrophobia. Because the machine is rather constricting, the patient is placed inside in tight conditions with can often lead to panicking while inside the machine. Another problem is the static field used to detect the blood flow can cause pacemakers and other devices the malfunction.

            The PET scanning technology works a little differently. The patient that is getting a PET scan is first injected with a quite painful dose of radioactive material. The most common materials are oxygen, fluorine, carbon, and nitrogen. Directly after the injection, different parts of the brain are activated and the contaminated blood goes to that section of the brain. As the radio active material breaks down, it releases a neutron and a positron. Because the positron is released, it hits a nearby electron and both are destroyed which gives off two gamma rays. Gamma Ray Detectors are used to find the exact place where this happens and gives the scientists an idea where the brain is functioning. This type of scanning has been recently used to detect the response to all types cancer therapy. It can show tumors and other abnormalities in the body. A recent case study used PET Scans to determine which side of the brain and where activity was during the use of sign language and motor movements. Because the scientist used this type of technology, it was easy to verify that the subjects’ right hemisphere was more active where he produced speech or sign language.

            Even though this is very useful type of brain imaging, there are limitations. A major one is that the patient is being injected by radioactive material, which is dangerous if the dose is too high. This type of imaging isn’t good for just taking a “picture” of the brain. This is specific for brain function.

            Brain imaging has come a long way since the 1900s ways of curing brain abnormalities and treatments for diseases like Alzheimer’s and cancers are being discovered through these technologies.

Psychology Studies: Empirical Research

Study: The effects of meditation on the brain

Aim: differences in brain activity from engaging in meditation over long periods of time

Participants: Trained meditators, Asians and Caucasians 

Procedure: Scientists made distractions with background noise to disturb the meditators as they were trying to focus on a red dot

Results: Less experienced meditators were more distracted and the more experienced ones kept focused easier 

Conclusion: Because the more experienced meditators had been meditating for years, this changed the brain in a way that it stayed more focused and not as easily distracted. 

Study: Changes in the brain after juggling training

Aim: To see if there was a difference in the brain structurally and functional after learning a new skill

Participants: 21 females and 3 males

Procedure: measure brain...3 months learning new skill, measure again…. 3 months not learning new skill… measure again

Results: 2 areas of the brain significantly different in size after training and after not training for 3 months

Conclusion: Brain areas associated with visually detecting motion grew large because the repetitive movement of the ball through the air strengthened the connections between the neurons

Study: Changes in the brain of experienced London taxi drivers 

Aim: to decipher if taxi drivers' hippocampus is larger than the normal persons brain. 

Participants: Experienced male taxi drivers (Fully licensed with years experience) and healthy male brains of people who don't drive taxis

Procedure: brain scans of all participants.

Results: both right and left hippocampus of taxi drivers were significantly larger in volume than that of normal males

Conclusion: redistribution of grey matter in the hippocamus due to intensive development of spatial memory skills, strengthing of neurons in that particular memory section

Study: PET evaluation of bilingual language compensation following early childhood brain damage.

Aim: To see the plasticity of the brain and how important Brocas area is to the speech part of a healthy adults brain

Participants: 37 year old man (MA) who despite his seemingly brain damage, can still speak. Also has a brain lesion in his left frontal lobe which most likely came from his case of Encephalitis at the age of 6 weeks. Also 12 control patients who were fluent in sign language

Procedure: using PET scanners, they monitored the participants performing speech or signs with some motor tasks

Results: MAs right hemisphere of the brain had more activity than the control subjects while performing speech and sign language. Also more agitated that controls

Conclusion: Language functions developed in right hemisphere rather than his left to adapt to his early brain damage