P1: Biological Approach Flashcards
(13 cards)
Describe the Biological Assumption of ‘Evolutionary Influences’
Evolutionary psychologists explain human behaviour based on Charles Darwin’s Theory of Evolution. This
theory states that species survive through natural selection; a process where those who are better suited to their environment tend to survive and therefore produce offspring.
The more evolved a person’s brain is, the more likely they are to survive in their ever-changing environment.
The genes that allow these individuals to be successful
are then passed to their offspring who will, in turn, also be
more successful. This means that genes within evolved families are more likely to be passed to each new generation. This is called ‘survival of the fittest’.
Describe the Biological Assumption of ‘Localisation of Brain Functions.’
Biological psychology assumes that specific areas of the brain are responsible for certain behaviours and mental processes, known as localisation of function.
The cerebral cortex can be divided into four sections, which are known as lobes:
1. Frontal lobe: located at the front of the brain, responsible for problem solving.
2. Parietal lobe: located in the middle section of the brain, responsible for sensory processes such as pain.
3. Occipital lobe: located at the back of the brain, responsible for interpreting visual stimuli.
4. Temporal lobe: located on the bottom section of the brain, responsible for interpreting auditory stimuli.
Describe the Biological Assumption of ‘Neurotransmitters’
Neurotransmitters are electrical messages, transformed into chemical messengers in order to be passed across a synapes, from the presynaptic neuron to the postsynaptic neuron.
Once a neurotransmitter reaches the postsynaptic neuron it is absorbed and changes the chemical signal back into an electrical one. The process then continues.
Each neurotransmitter has a different function, for example
Dopamine: controls bodily movements and emotional
responses. Dopamine deficiency is related to mental health
conditions such as depression.
Serotonin: affects both emotions and motor skills. Serotonin is the chemical that supports sleeping, eating and digestion.
Apply the assumptions of the Biological approach to explain two human behaviours.
Firstly, the biological assumption of the localisation of brain function can be used to explain Obsessive Compulsive Disorder (OCD). The orbitofrontal cortex, part of the frontal lobe, is involved in decision-making, impulse control, and evaluating the significance of potential threats. In people with OCD, this area is overactive. This means the brain may over-detect threats or generate excessive worry about potential dangers (e.g., germs, harm, or making mistakes). This may lead to obsessions—intrusive, unwanted thoughts that cause anxiety. Additionally, another area of the brain involved in OCD is the
caudate nucleus, located in the cerebrum of the brain, that is partly responsible for filtering out irrational impulses. Dysfunction here could therefore explain explain compulsive actions.
Secondly, the biological assumption of evolutionary influences could be used to explain aggressive behaviour. According to the theory of evolution by natural selection, traits that enhance an individual’s chances of survival and reproduction are more likely to be passed on to future generations.
Describe the main components of Psychosurgery.
The concept of psychosurgery applies a more physiological approach to a persons psychological wellbeing. Upon selection for psychosurgery, patient are thoroughly evaluated - both neurologically and psychologically - to identify the most case appropriate form of psychosurgery.
There are three main types of psychosurgery: Prefrontal Lobotomies, Stereotactic psychosurgery and Deep-Brain Stimulation (DBS).
Firstly, the prefrontal lobotomy is a procedure involving selective destruction of nerve fibres in the frontal lobe. Its purpose is to alleviate some of the severe symptoms associated with various mental disorders (such as relieving intense negative feelings in individuals with depression), as the frontal lobe is the area of the brain believed to be linked to mood regulation. Similarly, a neurologist in the 1930s developed a procedure called a prefrontal leucotomy, which involved drilling a hole into each side of the skull and inserting a sharp instrument, known as a leuctome, to destroy nerve fibres.
An alternative form of psychotherapy is the use of Stereotactic methods. In this surgery, MRI scans are used to locate exact abnormalities and connection in the brain and severing them. For example, in OCD treatments, a specific circuit linking to the orbital frontal cortex will be located and served, therefore relieving the patient of their OCD.
Thirdly, DBS is another form of psychosurgery involving the threading of wires through the skull. These wires are then attached to a battery pack implanted on the patients chest, producing an adjustable, high-frequency current that interrupts certain brain circuits believed to be causing the mental disorder. This more modern type of psychosurgery can therefore be stopped at anytime as it does not cause permanent damage to brain structures.
Evaluate the effectiveness of psychosurgery.
+ Research showing high success rates. Cosgrove & Rauch found that cingulotomies were effective in 56% of OCD patients and capsulotomies in 67%.
- Psychosurgery carries considerable and often irreversible risks—including cognitive impairment, emotional impairment, seizures, disinhibition, and death—for some patients. A 2008 follow-up study on patients who underwent capsulotomy for obsessive-compulsive disorder found that 40% experienced significant adverse effects, including memory problems, hypersexuality, and disinhibition severe enough to result in criminal behavior—such as a rape conviction linked to postoperative changes. Creates the argument that psychosurgery should be used as an absolute last resort.
- Expanding on this, by taking into account that in a modern society only ~25 surgeries are carried out per year, the effectiveness of psychosurgery may currently be hard to argue. This decline is likely due to the development of anti-psychotic and anti-depressant drugs. It could also be argued that these are much more suitable for treating mental illness as they are far less invasive in comparison to most psychosurgeries. Moreover, the studies conducted by Cosgrove & Rauch mentioned above consisted of small sample sizes and thus had low external validity. Clearly, drawing conclusions from those results would not be right.
Evaluate the ethics of psychosurgery.
- Major ethical implication of obtaining valid consent. In the early development of psychosurgical techniques, operations were usually used in mental asylums and prisons on patients who were not able to give valid consent. This idea is still somewhat relevant today, as it could be argued that the individuals seeking psychosurgery are often in dire and desperate conditions, therefore it could be the case that they are not mentally sound enough to make the informed decision to go through with psychosurgery.
+ However, in today’s society, rules of obtaining valid consent are stricter. The 1983 ‘Britain the Mental Health Act,’ called for more strict rules of consent to be obtained before psychosurgery treatment. Meaning the patient must give informed consent and have approval from two medical professionals before ongoing the treatment. - Psychosurgery is irreversible. A 2008 follow-up study on patients who underwent capsulotomy for obsessive-compulsive disorder found that 40% experienced significant adverse effects, including memory problems, hypersexuality, and disinhibition severe enough to result in criminal behavior—such as a rape conviction linked to postoperative changes. Therefore is unethical as can cause severe psychological and physical harm, has many potential side effects and is irreversible.
Describe the Methodology of ‘Raine et al’s Study: Abnormalities in murderers.’
Raine et al.’s study was a quasi-experiment (meaning that the independent variable, murderers who pleaded ‘NGRI’, had occurred naturally) which used a matched-pairs experimental design. The dependant variable of this research was the brain abnormalities/differences between the murderous individuals and the non-murderous, matched participant.
The participants of this study were separated into two groups: the ‘experimental group’ and the ‘control group.’
The experimental group - or, the ‘murderers’ - consisted of 41 individuals (39 men, 2 women) with a mean age of 34 yrs old. They had all been charged with murder and had all pleaded ‘not guilty, due to reason of insanity’ (NGRI). The participants were referred to the University of California for examination to obtain proof of their diminished capacity. Each of the murderers were proven to have some form of mental illness: 6 were diagnosed with schizophrenia, 2 with affective disorders, 2 with epilepsy, and 2 were diagnosed with a personality disorder. Other mental impairments recorded consisted of: 3 having a history of learning disability, 23 having had a history of traumatic brain injury and 3 having histories of psychoactive drug abuse. The participants were also required to be off medication/drugs and were tested with a urine scan prior to brain scanning.
The control group was formed by matching each participant of the experimental group with a non-murderous individual of the same sex and age. Additionally, the schizophrenic members of the experimental group were matched with 6 participants who also had diagnoses of schizophrenia, sampled from a psychiatric hospital. However, he other controls had no history of psychiatric illness and no history of physical impairments. None were on medication.
Describe the Procedure of ‘Raine et al’s Study: Abnormalities in murderers.’
The sample was obtained using opportunities sampling. A PET scan was used to study the active brain.
Firstly, all participants were given an injection of a ‘tracer’ known as Fluorodeoxyglucose (or, FDG). This tracer would then be taken up by active areas of the brain therefore allowing researchers to compare the brain activity of the experimental and control group.
Secondly, all participants were asked to do a ‘continuous performance task’ (CPT) aiming to specifically target areas of the brain, meaning that researchers could observe how the brain functioned.
The participants were given a chance to practice the CPT before receiving the FDG injection. Thirty seconds before the FDG injection was administered, the participants started to CPT so the initial task novelty (?) would not be FDG labelled. Ultimately, thirty-two minutes after the FDG injection was administered, a PET scan was done of each participant. Ten horizontal slices (pictures) of their brain were recorded using the cortical peel and box techniques. These findings were then recorded in the official, published article of the study so that it could be easily replicated in potential, future research.
Describe the Findings of ‘Raine et al’s Study: Abnormalities in murderers.’
Brain Differences:
- The study found reduced activity (i.e. reduced glucose metabolism) in the experimental group in areas previously linked to violence: such as, the prefrontal cortex, the left angular gyrus, the corpus callosum and in the left hemisphere amygdala, thalamus and hippocampus.
- The study also found increased activity (i.e. increased glucose metabolism) of the experimental group in areas that had not been previously linked to violence: such as, the Cerebellum and in the right hemisphere amygdala, thalamus and hippocampus.
- Additionally, the study found no difference in activity between the experimental and control group in other areas, not previously linked to violence: such as, the caudate, the putamen, the globus pallidus and the midbrain.
CPT Performance:
Both groups performed similarly in the continuous performance task, meaning that no observed brain differences were related to task performance.
Other Differences:
Some other differences between the experimental and control group were noted:
- Asymmetry: Six of the experimental group were left-handed and showed less amygdala asymmetry and higher medial pre-frontal activity than right-handed people.
- Ethnicity: 14 of the experimental group were people of colour. They showed no significant difference in brain activity compared to white participants.
- Head Injuries: The brain activity of the 23 participants with a history of brain injury did not differ from those with no history.
Describe the Conclusions of ‘Raine et al’s Study: Abnormalities in murderers.’
The findings of this research provide evidence that murderers pleading NGRI have different brain functions to non-murderous individuals. Violent behaviour can be explained through the disruption/dysfunction of brain networks and structures.
Raine stated that the findings of this research cannot be taken to conclude that violence us entirely predetermined by an individuals brain function. However, certain differences may pre-dispose someone towards violent behaviour.
The data do not demonstrate that murderers pleading NGRI are not responsible for their actions, nor do they demonstrate that PET scans can be used as a diagnostic technique.
The findings also cannot be generalised from NGRI cases to other violent offences.
Evaluate the Methodology of ‘Raine et al’s Study: Abnormalities in murderers.’
+ Research method of brain scans. Raine injected participants with an FDG tracer and then used a PET scan to take 10
mm horizontal slices of images of the brain. He found some significant differences in the NGRI and ‘normal’ controls, especially in brain areas such as the occipital lobe and amygdala. Scans are scientific and provide solid, observable evidence, increased internal validity.
+ Diversity and extension of the sample. In comparison to other research on NGRI murderers, Raine et al. took a large sample size (41 murderers and 41 control ptts.). These ptts. also had a large variety of traits, including 6 individuals with schizophrenia, 23 with a history of brain injury, 3 with a history of substance abuse, etc. Increased ecological validity.
- Sample is androcentric. Sample consisted of 39 male and 2 female ptts. By having a disproportionate balance of male/female ptts, results could argued to lack generalisability and validity. For example, the difference in the presence of female hormones (such as oestrogen) and male hormones (eg. testosterone) may have potentially had a relevance to this study that the sample size didn’t account for. Therefore, the sample could be argued to lack population validity.
- Quasi experiment. Independent variable used was individuals who had committed a murder and plead ‘Not guilty due to reason of insanity’ (NGRI). Weakness, prevents researchers from establishing cause and effect. As the i.v. developed outside of the study, it may have been influenced by other factors (such as home life during childhood, social influences, etc). Decreased internal validity.
Evaluation of the Procedure of ‘Raine et al’s Study: Abnormalities in murderers.’
