Brain Imaging PDF

Brain and Behaviour - Psychology is the scientific study of behaviour and mental processes. In the Brain Imaging Biological Approach, psychologists look at what biological phenomena can influence our behaviours, on...

Brain and Behaviour - Psychology is the scientific study of behaviour and mental processes. In the Brain Imaging Biological Approach, psychologists look at what biological phenomena can influence our behaviours, one core one being the brain, which is responsible for carrying out multiple functions. HISTORY - Brain research was limited to PMD (post-mortem dissections / autopsies) after the death of the patient. This is described as Invasive. It required consent. Now, the development of technology has SAQs - Describe the use of one technique used to study the brain in relation to provided researchers with machinery that allow for brain research non-invasively. The patient is alive, behaviour and is not under harm. It also allows for researcher triangulation - images and data can be sent [can't send a brain around - brain atrophy] ERQs - Evaluate the use of one technique used to study the brain in relation to behaviour / Discuss the use of one or more techniques used to study the brain in relation to behaviour. Examples of technique's to study the brain are the fMRI and MRI. They are distinguishable through two factors Spatial Resolution: ability to distinguish two differing structures detectable in a brain scan. It shows the location of brain parts fMRI - Functional Magnetic Resonance Imaging Temporal Resolution: the smallest time period in which a brain scan can register changes in the Measures the activity (function) of brain areas. Can be used in research with brain neurotransmitters, hormones, etc. And their influence on brain function --> behaviour MRI - Magnetic Resonance Imaging When activated in performance, regions of the brain are supplied with oxygenated blood. When placed in the magnetic field, the blood emits It uses a large magnet and pulses of radio waves to scan the brain, producing images of brain structures. energy. fMRI's use a BOLD (blood-oxygen level dependent) signal to see the Our body, which is mostly water (H2O), contains hydrogen protons with "spins" that align with the ranges of activity in the brain regions. Looks at on-going brain processes magnetic field emitted. The radio waves produced then flip the proton spins. After the field is Advantages - Informs them on brain activity and abnormal functions / turned off, the process of the protons returning to their normal spin is precession, which produces Non-Invasive / No radiation / Excellent spatial resolution another radio signal that the scanner receives and computes to a still image. Disadvantage - Expensive / Needs to discriminate between systematic patterns of activation instead of random from head movements, This device looks at still images that show cross-sections or "slices" of the brain. These images show the fidgeting, and random thoughts (activity is spontaneous - false positive) size, grey matter, damage, etc of the brain. The participants have to stay still, which may be troubling. / Temporal Solution requires a long-lasting procedure / Bias (misleading colours) / Lack Ecological Validity (in a machine) Advantage - Does not expose the participant to radiation / Abnormalities can reviewed (missing brain matter) / Has a good spatial resolution / Can compare images to show localization of function (functions are associated with brain parts. Abnormal functionality as a result of an abnormal brain part) Disadvantage - Picks up false abnormalities due to high resolution (creates anxiety and unnecessary treatment) / Participants with metal in their body cannot participate / Narrow space - children claustrophobia / Expensive KEY STUDIES Bechara et. Al (2000) (Quasi Experiment) - Localization of Function / Thinking and Decision-Making - Damage to vmPFC brings about impulsive thinking and decision-making. System 1 and System 2 thinking Maguire et. Al (2006) (Quasi Experiment) - Localization of Function / Brain Imaging - Visuo-spatial memory results in the change of the hippocampus volume - Taxi Drivers - smaller anterior & large posterior [navigating landmarks] / Bus Drivers - better at acquiring new visuo-spatial information. Passamonti et. Al (2012) (True Experiment) - Brain Imaging / Localization of Function / Neurotransmitters - Tryptophan --> Serotonin (5-HT) [Mood stabiliser] - PFC - Amygdala connection is weakened from the depletion. PFC activity lowers --> Impulsive reaction. Serotonin not sent to stabilize mood.