The brain is an organ located inside the skull and is part of the nervous system (Colman, 2009). The brain absorbs 70% of the body’s glucose and around 20% of the body’s oxygen (Holt, Bremner, Sutherland, Vliek, Passer & Smith, 2015) as the brain sends and receives electrical signals from around the body. The mind can be seen as “a collection of processes” (Reber & Reber, 2001). This means the mind is an umbrella term for all the processes in which the brain is active in, such as speech, executive functioning and personality as well as those processes that we are unsure of, such as intelligence and psychological disorders.
In this essay, I will discuss the advancements in methodologies for studying the brain, from lesion studies to PET and fMRI scans to electrophysiology techniques and how they have helped us to understand the mind. I will explore how studying neurodegenerative disease helps to improve our understanding of the mind. I will introduce the idea that to further understand the mind we also need to understand genetics and environmental factors, in relation to how the brain perceives.
Brain lesions have helped us learn a lot about the brain and the mind. Wernicke (1874, cited in Rorden & Karnath, 2004) found that injuries to the posterior temporal cortex causes difficulty in language comprehension. Phineas Gage sustained damage to his orbitofrontal and prefrontal cortex in the left side of the brain due to an iron rod going through his skull (Ratiu, Talos, Haker, Lieberman & Everett, 2004). After, Phineas Gage’s accident his personality changed. Harlow (1868, cited in Damasio, Grabowski, Frank, Galaburda & Damasio, 1994) believed that the change in his personality was caused by the damage to his brain, and therefore personality had a structural basis in the brain. Lesions studies, such as Wernicke and Phineas Gage, helped us to better understand the mind as damaged areas of the brain relates’ to different functions within the neural pathway and this can alter a person’s perception of the world (Ward, 2012).
New methods for studying the brain have been developed from studying naturally occurring brain lesions, from which parts of the brain we assumed to have a specific function, to structural and then functional imaging which allows for every part of the brain to be active during a task to be shown (Rorden & Karnath, 2004). These developments came about as lesions studies are not controlled experiments, which meant that you could not be sure if the damage had caused this behaviour (Ward, 2012).
Methodologies of imaging the brain, such as Positron emission tomography (PET), magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI) and computerized tomography (CT) are used to study the brain. CT and MRI scans created structural images of the brain, whereas fMRI and PET scans show functional images of the brain (Ward, 2010). The most common used brain imaging in psychology is PET and fMRI scans. PET scans measure the flow of blood within the brain (Holt et al., 2015). Radioactive tracers are injected into the body and they emit a signal in the bloodstream which helps locate where the blood is flowing in the brain (Ward, 2010). fMRI operates by measuring the flow of blood in relation to oxygen levels (BOLD) (Ward, 2010). BOLD works because neural activity increases the demand for oxygen, which results in an increased blood flow. The area of the brain where there is an increased blood flow is assumed to be the part of the brain which is functioning. fMRI has helped scientists study and identify the structure and functions of the brain.
Although, brain imaging has helped identify aspects of the brain which have a specific function, it cannot show anything on the nature of the mind and therefore fails to fully understand the mind (Coltheart, 2006).
Neuroimaging can explain more about the mind by helping to eliminate or support competing psychological theories to help further our understanding of the mind. Coltheart (2006) claims nothing about the mind can be understood from neuroimaging as no study has distinguished how the brain performs a task. Nevertheless, Henson (2005) claims that neuroimaging can help aid the understanding of the mind by supporting or refuting a theory it can tell us how an activity is conducted.
Electrophysiological techniques, such as electroencephalography (EEG), measures electrical signals from neuron activity (Holt et al., 2015). EEG uses an array of electrodes placed on the scalp to record neural activity, but are not specific (Ward, 2012). EEGs produce event-related potentials (ERPs) when provoked by cognitive tasks and specific stimuli (Ward, 2012). EGG helps to understand the mind as they will always elicit an electrical signal showing that parts of the brain are functioning and can potentially show us how things function within the brain (Ward, 2012). Transcranial magnetic stimulation (TMS) is used to temporarily stimulate neurons in the brain which delays the time taken to complete the task (Ward, 2012). The electrical stimulation occurs by placing a TMS coil over the area of the brain you wish to stimulate, this will produce a magnetic field because of a change in electrical currents, which will then activate the neurons in the brain causing its function to be disrupted (Ward, 2012). TMS research can help understand the mind as it can make “virtual lesions” on the brain, which may help us to understand whether disruption to an area of the brain results in a change of behaviour (Ward, 2012).
Brain damage can occur due to neurosurgery, strokes, head injuries, tumours, infections or neurodegenerative disorders which can affect the function of the brain (Ward, 2010). Alzheimer’s disease (AD) is a progressive neurological disease which is the biggest cause of dementia in the elderly (Holt et al., 2015). Dementia causes a deterioration in cognitive abilities, including memory loss, confusion and changes in personality (Holt et al., 2015). Brain imaging (PET and fMRI) has allowed scientists to follow the evolution of the disease, identify the disease before symptoms have been expressed, and to help produce treatments that may help improve cognitive functioning within patients who suffer from AD (Nordberg, Rinne, Kadir & Långström, 2010; Holt et al., 2015). MRI imaging shows a decrease in hippocampal and entorhinal cortex size (Jack, Petersen, Xu, O’Brien, Smith, Ivnik, Boeve, Waring & Tangalos, 1999, cited in Ramein & Jagust, 2012). MRI images helps us to understand the deterioration of cognitive abilities within those suffering from AD (Ramein & Jagust, 2012), which in turn helps us understand the way in which the mind fails to perceive properly.
Studying genetic and environmental factors can help us to develop our understanding of the mind. Difficulty in perceiving fear has been linked to damage in the amygdala (Rorden & Karnath, 2004). People tend to link antisocial behaviour disorder with damage to the amygdala, however, antisocial behaviour can be linked to genes and environmental factors. Moffitt (2005) reports a 0.4 to 0.5 hereditability estimate, which mean 40-50% of antisocial behaviour in children is solely due to genetic factors. Moffitt (2005) discusses the influence of environment on genes. Children who suffer from antisocial behavioural disorder often end up in the system. Adoptive parents of these children’s can face difficulties when trying to raise them, which leads to stricter discipline being taken producing more antisocial behaviour (Moffitt, 2005). Monoamine oxidase A (MAOA) breaks down neurotransmitters, such as serotonin and dopamine (Gunter, Vaughn & Philibert, 2010). Low activity in the MAOA gene has been associated with antisocial behaviour (Fowler, Langley, Rice, Van den Bree, Ross, Wilkinson, Owen, O’Donovan & Thapar, 2009), normally in association with a stressor. Studying genetics and environmental factors helps understand the mind as it demonstrates a fuller picture of the brains processes.
In conclusion, whilst studying the brain helps to identify and localise functions of the brain to specific areas due to the advancement in brain imaging methodologies, other areas of science and psychology can further the understanding of the mind. Genetics help to identify underlying biological basis that can interfere with behaviour and actions, such as the MAOA allele and hereditability estimations. Heritability estimations show how much variation in behaviour is due to genetics alone. Environmental factors can also influence behaviour and performance because the way you are raised can affect the person you turn out to be and the mind set you have. Therefore, to fully understand the mind you must not only study the brain but other aspects, such as genetics, to understand the mind.