biological approach- component 1 Flashcards
Describe and explain the assumption of ‘Evolutionary Influences’
This assumption is states that human behaviour is explained through natural selection. This means that traits that enhance the chance of survival and reproduction are passed down through generations. Those with more characteristics most suited to their environment are more likely to have evolved and the more evolved an individual is, the more likely they are to survive their changing environment. These genes ar epassed to offspring who will then also be evolved and so the genes that allow them to survive their environement will be passed down through generations. This is known as Survival of the fittest.
- According to Trivers, romantic relationships are influences by different levels of investment in offpsoring by males ad females. Females put in mor e of an investment into the offspring in terms of their health, so look for a male who can provide shelter for her and her child. Males put in less investment, as they can produce many offspring with many different women so look for young and fertile women
Localisation of Brain Function
Different areas of the brain are responsible for different functions. For example, there are four lobes within the brain, the frontal, parietal, occipital and temporal. The frontal lobe is responsible for problem solving and the parietal lobe is responsible for sensory processes such as pain.
- The orbitofrontal cortex (OFC) is involved in impulse control and response inhibition. OFC influences mate selection deciding whether a potential mate is desirable. When shown attractive faces, it should be rewarding from a mate selection perspective, so it would be expected thar OFC action is present.
Neurotransmitters
Neurotransmitters are chemical messengers that are passed from the presynaptic neuron to the postsynaptic neuron across the synapse. Once released from presynaptic neuron, they will either inhibit or stimulate receptors in the other neuron.
- Serotonin plays a role in mood, sleep and appetite. Those with depression often have low levels of serotonin . Some antidepressant medications work by increasing the availability of serotonin at postsynaptic receptor sites.
- High levels of dopamine associated with schizophrenia symptoms . Antipsychotics block dopamine activity and so reduce schizophrenic symptoms.
Biological explanation for relationship formation:
-relationships form with those with certain traits. Traits enhance chance of survival as they are naturally selected and so increase reproductive success. Males can mate frequently and so look for youthful and fertile females (smooth skin, glossy hair, small waist). Females look for males who can provide food, shelter etc for her and her offspring.
- neurotransmitters influence emotions and in turn influence perception of others. Dopamine is associated with pleasure seeking and reward driven behaviour, so achieving the goal of finding a partner will increase dopamine levels. This is why humans are driven to form relationships. Oxytocin linked to human bonding and increases trust and loyalty. High levels linked to romantic attachment as a lack of physical contact with partner reduces oxytocin levels, leading to the want to bond with their partner again. Humans have a natural chemical drive to bond with others.
- Kin selection: traits that enhance survival of those with similar genes are selected to promote the survival of the group’s genes. Humans have a natural incentive to look after siblings to ensure they are protected and healthy.
How do the biological assumptions apply to drug therapy?
Main components of drug therapy:
ANTIPSYCHOTIC DRUGS: treat psychotic mental disorders incl. schizophrenia. Conventional antipsychotics combat positive symptoms (delusions, hallucinations). They block the action of dopamine by binding to and not stimulating dopamine receptors. Atypical antipsychotic drugs act by temporarily occupying dopamine receptors and then rapidly dissociate to allow normal dopamine transmission.
- ANTIDEPRESSANT DRUGS: depression due to lack of serotonin produced in the synapse. Reduce the rate of reabsorption of serotonin and other neurotransmitters, or by blocking the enzymes that break down the neurotransmitters in a brain with depression. These mechanisms increase the amount of neurotransmitter available. Selective serotonin reuptake inhibitors (SSRIs) block the transporter mechanism that reabsorbs serotonin into the presynaptic cell, so more serotonin is left in the synapse.
ANTIANXIETY DRUGS:
Benzodiazepines (BZs) slow down the activity of the CNS by enhancing activity of GABA (neurotransmitter) that is a natural anxiety relief. Beta-blockers (BBs) reduce adrenaline activity and noradrenaline which are stress responses. BBs bind to receptors on cells of heart and other parts of body stimulated during sympathetic arousal . This makes it harder to stimulate cells in these parts of the body so the heart beats slower so blood pressure falls and there is less stress of heart . Person feels calmer and less anxious.
Evaluation of drug therapies: Effectiveness
DRUGS VS PLACEBO: Typically a randomised control trial is used to compare effectiveness of drug versus placebo . Soomro et al. (2008) reviwed 17 studies of the use of SSRIs with OCD patients and found the drugs were more effective than placebos in reducing OCD symptoms in the short term. Kahn et al (1986) followed 250 patients over 8 weeks and found BZs more effctive than placebos in the short term. However most studies only show the effectiveness of drugs in the short term, so little long term data exists.
SIDE EFFECTS: Many drugs have negative side effects, such as SSRIs have common side effects of nausea, headache and insomnia. They cause the individual to not want to take the drug. This effects the quality of life for the patient by causing them further physical and psychological harm.
SYMPTOMS NOT CAUSE: don’t address the underlying cause of the condition. For example, if an individual is suffering depression in adulthood due to childhood trauma, drug therapy may provide short term effectiveness, but won’t deal with the condition long term. This leads to ‘revolving door syndrome’, where patient is back and forth to doctor as disorder never cured.
COMPARISON WITH OTHER TREATMENTS: cheap therapy compared with others. In the UK these drugs are prescribed on the NHS. The practitioner has to invest less time in the patient as they only need to meet them every couple of months after initial consultation. So, this therapy is effieicent and easy to administer compared to others.
Evaluation of drug therapies: Ethical Issues
USE OF PLACEBOS: It may be argued that no patient should be given a placebo as this is a treatment known to be inferior to the real drug. Instead, existing effective treatments should be used as the control condition when new treatments are tested.
PATIENT INFORMATION: Issues regarding valid consent. Many patients will find it difficult to remember all potential side effects of the drug or they may not be in the right mental state to give valid consent. For example, those with schizophrenia are not menatlly stable enough to give valid consent to take the medication. These patients should be assisted when making an informed decision about consenting to taking any drug therapies. Furthermore, medical professionals may withhold information about the drugs such as not fully explaining that the pharmacological benefits of the drugs are slim. Some medical professionals may exaggerate the benefits of the drug and not inform patient of other therapies available due to the easy solution of drug therapy.
Classic evidence: Raine (1997): Methodology
- quasi experiment with matched pairs design
- IV= NGRI or not
- DV= brain differences
PARTICIPANTS:
opportunity sample used
- NGRIs (Experimental group)
-41 NGRIs (39 men, 2 women).
- Participants referred to University of California for examination to obtain proof of their diminished capacity, due to a mental disorder. These disorders included schizophrenia, head injuries, psychoactive drug abuse, epilepsy, affective disorder, learning disorders and personality disorders.
- kept drug free 2 weeks prior to brain scans.
Control group: matched each NGRI with a non murderer of the same sex and age
- Schizophrenics matched with 6 non murderer schizophrenics. All other controls had no history of mental disorder in themselves of close relatives or serious physical disorder. None took medication.
Raine (1997): Procedures
- PET scan used to study the brain activity.
- All participants given an injection of a glucose ‘tracer’ that is taken up by active areas of the brain, so can be used to compare NGRI and control brains.
- All particpants used to perform continuous peformance task (CPT) which specifically aimed to activate the target areas of the brain so the investigators could see how the different areas functioned.
1. Participant given a chance to practice CPT before receiving glucose tracer injection.
2. 30 seconds before glucose tracer injection, participants started CPT, so that the tracer didn’t pick up the initial novelty of the CPT.
3. 32 minutes after the glucose tracer injection a PET scan was conducted on each participant. 10 images of their brains were recorded.
Raine (1997): FINDINGS
BRAIN DIFFERENCES: reduced activity in the NGRI brain in areas previosuly linked to violence: Prefrontal cortex, corpus callosum and amygdala, thalamus and hippocampus only in the left hemisphere.
- Increased activity in NGRI brains in areas not previosuly linked to violence: Cerebellum and amygdala, thalamus and hippocampus in right hemisphere.
- NGRIs had reduced activity in areas previously linked to violence.
- NGRIs had abnormal asymmetrie- reduced activity on left side of brain, greater on right
- NGRIs had no differences in brain structures associated with mental illness but not violence.
PERFORMANCE ON CPT:
both groups performed similarly, so observed differences not related to CPT.
OTHER DIFFERENCES NOT CONTROLLED FOR: between NGRIs and control group:
- 6 NGRIs left handed but they had less amygdala asymmetry and higher medial prefrontal activity than right handed murderers.
- 21 NGRIs had previous head injuries but did not differ to control group with no history of brain injury.
Raine (1997): CONCLUSIONS
NGRIs have different bfain functioning to non murderers. However, violent behaviour is very complex and cannot be reduced to being explained by a single brain mechanism. Multiple brain mechanisms would explain it more effectively, but would not cause criminal behaviour, only predispose an individual to violent behaviour.
CONFOUNDING VARIABLES:
- study carefully designed
- large sample with matched controls
- However, in the study, head injury and IQ have not been ruled out as contributory factors.
WARNING: the results do not demonstrate:
1. don’t show violent behaviour is determined by biology alone. The results show that social, psychological, cultural and stituational factors also play important roles in predisposition to violence.
2. that murderers pleading NGRI are not responsible for their actions, nor that PET scans can be used to diagnose violent individuals.
3. that brain dysfunction causes violence. It may even be that violence causes brain dysfunction.
4. do not show that violence can be explained by the results, as the results only relate to criminal behaviour.
Evaluate Raine’s research in terms of methodology and procedures
- weakness: quasi experiment, so causal conclusions are not justified. Findings do not show violent behaviour determined by biology alone. Raine et al suggest psychological, cultural and situational factors have important rules in the predisposition to violence .Findings may be misinterpreted and assume criminality predetermined and inescapable.
- Strength: PET scans used, which allow more detailed images of brain and allow brain activity to be examined, which was not possible with past techniques such as post mortem examinations.
- sample not representative of all violent individuals, just murderers. Do not show all violent people have such brain dysfunctions. Can only draw conclusions from NGRIs
Evaluate Raine’s research in terms of alternative evidence
- Yang and Raine (2009): meta analysis of 43 imaging studies considering antisocial and violent behaviour. Concluded reduced prefrontal activity in antisocial and/or violent people
- findings supported by genetic studies indicating criminal gene. Tiihonen et al (2015) anaylsed genes of 895 prisoners and found association between MAOA gene and increased likelihood of violent offending
- BUT genes only predisposing factors (may have genetic and brain characteristics of violent criminal but not be one)
Evaluate Raine’s research in terms of ethical issues and social implications
- NGRI participants may not have been mentally competent to provide valid consent. May not have fully understood what they required to do
- they may have found performance task difficult, lowering self esteem (psychological harm)
- may not have realised what PET scan involved, so may have been stressful (psychological harm)
- research indicates murderers are genetically predisposed, so this may have consequences on others who display similar brain abnormalities. They may be imprisoned without trial or reference to social circumstances.
- information on brain abnormalities could be used against them in trial.
What are the strengths of the biological approach?
- scientific, as approach has clear measurable variables. Approach can be used to help in scientific research, to support biological explanations
- deterministic. If it is predetermined that a biological factor predetermines behaviour, then it’s more likely to be treatable. E.g. neurotransmitter dopamine linked with Schziophrenia, which has come from many sources. drug amphetamine known to increase dopamine levels and large doses can cause sch symptoms (e.g. hallucinations). MAOA gene been found in violent criminals, predisposing them to violence.
- successful applications. Research into relationship between neurotransmitters and criminal behaviour can help develop drug therapies for prisoners, leading to lowered recidivism and safer society. Cherek et al (2002) showed that males with conduct disorder and criminal behaviour had reduced aggression and impulsivity levels after 21 days of SSRI antideprresants compared to control group with placebos.
What are the weaknesses of the biological approach?
- reductionist. reduce complex behaviours to simple explanations e.g. stress caused by adrenaline hormone. Simplified explanations may prevent reaching a true understanding of target behaviour.
- Does not take into account environment (nurture) and psychological factors. Ignores socioeconomic background, upbringing, education etc. An interactionist approach that takes into account both nature and nurture may be more appropriate.
- nomothetic. makes generalisations about people to find similarities, ignoring individual differences. Research often generalises results from small sample to everyone. Research tends to only use male participants and ignore women, due to possible female hormone cycle interference. Also ignored other genders such as Trans community and non binary. Not appropriate to apply same explanations from men to all other communities. This is a beta bias.
- e.g. Taylor et al (2000) suggest men tend to react to stress with ‘fight or flight’ response but women show a ‘tend and befriend’ response (nurturing offspring and seeking help from other females. This difference has been explained by oxytocin hormone which women produce when stressed.
