2 (biological) Flashcards
LOCALIZATION OF FUNCTION
Localization of function is the idea that certain parts of the brain correspond to specific brain functions. For example, the conversion of short-term memory to long-term memory is a process controlled by the hippocampus. The hippocampus is a complex brain structure thats plays a major role in the process of learning and in memory development. This idea can be seen in the study of HM by Milner.
MILNER/HM: The aim of Milner’s case study on HM, who had his hippocampus removed, was to investigate the role of the hippocampus on memory. The procedure involved utilizing HM’s IQ tests, observing his behavior, interviewing him and his family, and taking MRI scans of his brain. The results found that the hippocampus is responsible for long-term memory, but not short-term memory, as HM still retained that ability. This supports the idea of localization of function because HM’s hippocampus being removed affected only a specific function of his brain, rather than damaging the entire brain itself.
NEUROPLASTICITY
Neuroplasticity is the idea that our brains grow and change through learning and experience. For example, something as simple as driving a new route that you’ve never taken before can create new neural pathways in your brain which is something that is explored in the Maguire study.
MAGUIRE: The aim of Magire’s study was to compare the brain’s of London taxi driver’s to non-taxi drivers. The procedure involved measuring and comparing the volume of the taxi drivers and non taxi driver’s hippocampus in a single-blind fashion. The results found that the taxi driver’s brains had a larger volume compared to those of non-taxi drivers. In addition, the amount of time spent as a taxi driver correlated with participants’ volume of their right posterior hippocampus. This study supports the idea of neuroplasticity because it shows that through the taxi drivers extensive and elongated memorization of London’s street system, the size of their brain measurably increased as a result.
NEUROTRANSMISSION
Neurotransmission describes the transfer of information between neurons. This process is controlled by neurotransmitters, which are chemical messengers secreted by neurons in order to send signals to its target cell. An example of a neurotransmitter is dopamine which is responsible for emotions such as pleasure, adrenaline, or attraction. A study that demonstrates the effects of dopamine is the Fisher et al study.
FISHER ET AL: The aim of Fisher et al’s study was to test whether there are specific neural mechanisms associated with romantic love. The procedure involved 10 women and 7 men looking at photos of their partner for 30 seconds while their brain was being scanned by a fMRI scanner. The participants also completed an interview measuring the intensity and duration of their relationship. The results found that the participants experienced increased brain activity in the areas of the brain with high levels of dopamine neurons as they were looking at the photos of their partner. Additionally, participants who were described as more passionately in love, had more active brain reward circuitry.
HORMONES
Hormones are chemical messengers that affect behavior. They are secreted by glands in the endocrine system and are sent directly into the bloodstream. An example of a hormone is adrenaline which activates the sympathetic nervous system. Adrenaline plays a role in memory formation which is explored in the McGaugh & CaHill study.
MCGAUGH & CAHILL: The aim of McGaugh & CaHill’s study was to investigate the role of emotion on memories. The procedure involved 2 groups being told either a mundane story and an emotional story. The results found that participants who heard the emotional story could recall more details from the story than participants told the mundane story.
PHEROMONES
Pheromones are chemicals released into the environment by an animal that affect the behavior of those around them. They can be useful for determining species, sex, and genetic identity of the individual from which it is being released. The MHC gene is associated with the coding of proteins within the immune system. Particularly strong immune systems and opposing genetic identities are factors that influence whether an animal is attracted to a potential mate which is a process that requires pheromones to be released in order to be able to identify. Wedekind’s study explores this idea of pheromones and whether they are present in humans.
WEDEKIND: The aim of Wedekind’s study was to determine whether the MHC gene affects mate choice. The procedure involved women ranking T-shirts worn by men based on how pleasant they smelled. The results found that on average, women ranked the men who were MHC dissimilar to them higher in pleasantness than those who were MHC similar to them. This study tells us that women could potentially determine whether their partner has opposite DNA to them, which supports the idea of pheromones since they influence the ability to attract a mate.
GENES
Genes refer to the information within your DNA that determine your traits and are the framework for your actions within an environment. Inherited genes contribute to the complex behaviors we may exhibit such as communication, mental disorders, or intelligence. Genetic relatedness measures the similarities between two individuals’ DNA sequence to determine how related they are to each other. The Minnesota twins study explores the idea of genetic relatedness and the degree to which inherited genes affect the behavior of intelligence.
MINNESOTA TWINS: The aim of the Minnesota Twins study was to investigate if the environment and genetics play a role in human behaviors, such as intelligence. The procedure involved comparing 100 sets of twins, specifically those raised together versus those who were raised apart. The results found that 70% of intelligence can be attributed to genetic inheritance and 30% can be attributed to alternative factors. This conclusion was made because concordance rates for intelligence were higher in twins raised apart than fraternal twins raised together. The Minnesota twins study supports the idea that genes have an influence on the human behavior of intelligence because genetic relatedness and concordance rates were correlated, suggesting that intelligence is based more on your genetic make-up than the environment you are exposed to.
EVOLUTION
Evolution refers to organisms changing from generation to generation as a result of a change in heritable characteristics. The theory of evolution states that biological organisms are motivated by survival and reproduction. Natural selection plays a role in increasing the characteristics within a population that are better adapted to their environment over a specific period of time. Disgust is an example of an evolutionary response that is theorized to have been passed down from our ancestors in order to protect against eating something that is harmful. The evolutionary behavior of disgust is investigated in Fessler’s study.
FESSLER: The aim of Fessler’s study was to find out if disgust helps compensate for a suppressed immune system during the 1st trimester of pregnancy. The procedure involved asking women to rank 32 disgusting scenarios based on how repulsed they were by them. The results found that women in their 1st trimester of pregnancy had higher disgust sensitivity than women who were in their 2nd/3rd trimester of pregnancy. This suggests that women naturally develop a higher disgust sensitivity in their first trimester of their pregnancy in order to protect themselves from getting sick and thus, increasing the survival rate of their baby. Fessler’s study supports the idea of evolution because it shows us that the human characteristic of disgust was obtained to increase the likelihood of an individual’s baby surviving.
