Brain imaging technology is a non-invasive method used by researchers to gage human brain activity and its correlation to behavior. Brain imaging technology is effective because it is non-invasive, safe, and painless, it provides new resources to create cures to brain disorders, and it recognises localized portions of the brain and how they are affected by mental disorders. On the other hand, brain imaging technology can be flawed because it is expensive, it cannot always detect the exact location of activity, it doesn’t display an exact cause and effect of behaviors, images of one brain cannot be applied to another because no two brains are identical, and localization is limited. Also, patients are exposed to radiation, which calls ethics into question. There are numerous types of brain imaging technologies, each used for a slightly different purpose. Three specific types are Magnetic Renaissance Imaging (MRI), Positron Emission Tomography (PET), and Electroencephalography (EEG). A few researchers that used brain imaging technology in their studies are: Maguire et al (2000), who used MRI to discover advanced spatial skills correlated to growth in the hippocampus, Raine et al (1997), who used PET to determine whether there are brain abnormalities in criminals who plead not guilty to murder because of insanity, and Hart et al (2014), who used EEG to find if the brain’s theta and beta waves are reactive to threatening images. Maguire, Raine, and Hart used brain imaging technology, specifically MRI, PET, and EEG, for their purpose of investigating human behavior in the biological approach to psychology.
MRI machines measure emission levels of atomic nuclei in response to magnetic fields. Maguire et al (2000) decided that using MRI would be beneficial to her study, in order to gage whether London taxi drivers’ brains have more neuroplasticity, a biological process where the brain shifts, than regular people. London taxi drivers are well known for having advanced and superior navigational skills, or being “on the knowledge”, due to their extensive training. The hippocampus’ localized functions are navigational skills and spatial recognition, so Maguire theorized that there could be an increase in grey matter within the brain. After taking the MRI scans, Maguire and his team found that compared to a control group, there was great growth of grey matter in the hippocampus of London taxi drivers. From the scans, the researchers were able to conclude that the usage of the hippocampus, caused plasticity and expansion in the brain. In this instance, the use of brain imaging technology was extremely beneficial to the researchers because the scans provided data that no other form of research could. A limit to the use of MRI in this study is that the subjects were exposed to radiation. This doesn’t necessarily cause direct physical harm, but frequent exposure to radiation is unethical because it is linked to various cancers. The study could have been improved if there were MRI scans taken before and after the subjects acquired their driving skills, as a direct cause and effect could have been found. However that wouldn’t be logical because of the cost of multiple MRIs and extreme exposure of the subjects to radiation. Maguire’s use of MRI in her study enhanced understanding of localization and neuroplasticity, which are two vital aspects of the biological approach to psychology.
PET machines pick up on blood flow to certain regions of the brain through a tracer that is inserted into subjects’ brains. Through measuring blood flow to certain areas upon exposure to different environmental factors, researchers can learn about localization of functions, which is a key idea in the biological approach to psychology. Raine et al (2005) created a study to find the neural mechanisms that correspond to love. Raine and his team found seventeen “deeply in love” subjects to undergo fMRI scans while viewing pictures of their loved ones. The results of the study showed that in the brain’s dopamine-rich reward system, consisting of the right ventral tegmental and the right caudate nucleus, the blood flow was particularly strong during the fMRI scans. Researchers concluded that the passage of dopamine through its reward system contributes to feelings of romantic love. This study discusses evidence that points to a bidirectional relationship between the physical reward system in the brain, and the feelings developed in human romantic relationships; this study displays the role dopamine’s biological influence on psychology. The use of the fMRI machine was sensible because based off the scans, researchers were able to identify where blood flow is active, and therefore which areas of the brain were most reactive to the release of dopamine. However, the use of fMRI in this study created limited results because researchers could not pinpoint the exact location of dopamine itself in the brain, so no exact correlation could be found. The fMRI scans allowed researchers to discuss the relationship between distribution of dopamine in specific areas of the brain and romantic feelings.
EEG machines measure electron impulses that are generated by neural circuits. Subjects get electrodes attached to their scalp pick up on changes in electric potential of the scalp areas. This type of brain imaging technology is favorable for measuring general brain activity. Hart et al (2014) conducted a study using EEG, that aimed to determine if the brain’s theta and beta waves are reactive to visually threatening images. In the study, twenty six adults wore EEG caps, while being shown a total of two hundred twenty four images, separated into two categories: threatening, and non-threatening. The results from the EEG machine showed that theta wave activity started in the amygdala, also known as the fear center and located in the back of the brain, interacted with the hippocampus, which corresponds to memory, and finally traveled to the frontal lobe, where the processing areas were engaged. Beta wave activity occurred in the motor cortex; this beta wave activity indicates the preparation of the motor cortex, in case the subject needed to run to escape the threat. These wave patterns represent the human activation of fear, identification of it, then the processing of the emotion. The EEG was useful in this study in order to identify brain waves and linking them with specific reactions and behaviors. A limit to using EEG in this study was that the electrodes only pick up currents on the scalp level, so they cannot provide accurate data on processes deep in the brain. Overall, the EEG machine was useful in advancing researcher’s understanding of how the brain’s theta and beta waves are impacted by threatening images.
The use of MRI, PET, and EEG brain imaging technologies were effective in Maguire, Raine, and Hart’s studies of biological psychology. Due to the use of brain imaging technology in all three studies, the results helped advance general knowledge about neuroplasticity, which is a biological process that impacts psychology. To a certain extent, each form of brain imaging technology allowed researchers to be successful in conducting a precise study; due to obstacles that each form of brain imaging technology presented, the results of the scans did not always display a clear answer to the question posed in the aim of their experiment. All in all, brain imaging technology is effective in investigating human behavior in the biological approach to psychology.