Biological Level of Analysis

General Learning Outcomes

Syllabus Question: Outline principles that define the biological level of analysis

The three principles that define the biological level of analysis are:

1.      Patterns of behavior can be inherited

2.      Animal research may inform our understanding of human behaviour

3.      Emotions and behaviour are products of the nervous and endocrine systems

Syllabus Question: Explain how the principles that define the biological level of analysis may be demonstrated in research

1.      Patterns of behaviour can be inherited

Genetics play a role in behaviour. This is supported by family studies, twin studies, adoption studies and evolutionary psychology.

Twin Studies: Identical (monozygotic twins) have exactly the same genotype. Fraternal twins (dizygotic) are like any other siblings, sharing only 50% genetic relatedness.   

Case Study:

·         Bailey and Pillard (1991) studied monozygotic and dizygotic twins to measure how often when one was homosexual, the other would be too.

·         Aim was to see if homosexuality was caused by genetics. 161 males were tested, all over the age of 18.

·         Results showed that dizygotic twins had a concordance rate of 22% whereas monozygotic twins had a concordance rate of 52%. The environmental factors were blamed for the monozygotic twins’ concordance rate being below 100%.

·         The research showed that homosexuality can be inherited and can be genetic.

Evolutionary psychology:

·         Humans have changed and continue changing physically and in terms of behaviour according to the demands of the environment.

·         Genetic information is passed on from parent to child. Over time, physical characteristics and behaviours that are helpful to an individual or social group in terms of surviving and reproducing can be passed on.

2.      Animal research may inform our understanding of behaviour

·         Humans and animals are different due to evolution but are fundamentally the same, humans are animals, thus it is valid to make predictions of human behaviour based on animal research.

·         The mechanisms that underlie behaviour are the core similarity humans share with animals.

·         Defined as being the use of destructive and non-destructive testing upon various animal species to better understand the mechanisms of human and animal behaviours, emotions and thought processes.

Case Study:

·         Ivan Pavlov (1927) demonstrated through the use of dogs; ‘classic conditioning’

·         Dogs would salivate when shown food. Every time it was meal time, a bell would be sounded with the food.

·         Result = dogs began salivating at the sound of the bell even when food was not presented, thus demonstrating how humans can be trained into responding to a certain stimuli in a particular way.

3.      Emotions and behaviour are the products of the anatomy and physiology of the nervous and endocrine systems

·         Suggests that all observable behaviour, including mental processes (i.e. emotions and cognitions) can be traced back to physiological events. This is supported by:

o   The effect of neurotransmitters

o   The effect of hormones

o   The effect of brain localization

·         Emotions are seen to be produced by activity in the brain (nervous system) and by the activity of the hormones (endocrine system).

Syllabus Question: Discuss how and why particular research methods are used at the biological level of analysis.

Three research methods used in the biological level of analysis are; experiments, case studies and correlational studies.

1.      Experiments

·         A research method in which the investigator manipulates a variable under carefully controlled conditions and observes whether any changes occur in a second variable result.

·         Takes place in a controlled environment which is both an advantage and disadvantage.

·         Placebo effect: the subject may react the way in which it is expected to, altering the reliability of the results.

·         Advantage: Can run the experiments on animals. Fruit flies which have a very short life span can be observed in a controlled environment and changes made to the environment will allow researchers to observe a form of evolution in a short timeframe.

·         Disadvantage: Experimenting on animals is argued to be morally wrong therefore it must be asked whether it is valid to do experiments on them and generalize them to humans.

2.      Case Studies

·         An in-depth investigation of an individual or small group subject.  

·         Adv: Researchers can take adv. Of naturally occurring irregularities by obtaining detailed information about the participant’s condition.

·         Very useful in medical context.

·         Very little harm done to participants.

·         Disadv: researchers must make sure to protect the identities of those involved in the case study.

·         Cannot make generalizations or reliable conclusions from the studies.

3.      Correlational Studies

·         Takes scores on two or more measures and works out the relationship between them.

·         Does not require the manipulation of an independent variable that may harm the participant.

·         Usually used in twin and adoption studies (important link between genetics and behaviour).

·         Not cause and effect like experimental studies.

·         Looks at the extent to which two variables are related.

·         Positive correlation = high scores on variable X and Y and vice versa.

·         Negative correlation = high score on X variable à low score on Y variable and vice versa.

Syllabus Question: Discuss ethical considerations related to research studies at the biological level of analysis

1.      Laboratory experiments:

·         Animals experience pain and humans should protect them from harm.

·         Animals experience less pain than humans

·         The use of animals must be supervised by a competent person who can care for the animal.

·         Research must be justified if animals must undergo pain.

·         Must use anesthetic if surgery is involved.

·         If an animal must be killed for research, it must be done quickly and as painlessly as possible.

2.      Case Studies

·         The researcher must take personal information regarding the subject which may be published in the report.

·         The researcher may uncover psychological damage which the individual may not be aware of or consent to.

·         Guidelines must be adhered to: informed consent required, no deception, participant has the right to withdraw, must be debriefed and confidentiality rights protected.

Main ethical principles in psychological research:

·         Participants’ rights

·         Confidentiality

·         Voluntary Participation

·         Withdrawal Rights

·         Informed consent procedures

·         Deception

·         Debriefing

Physiology and Behaviour

Syllabus Question: Explain one study related to localization of function in the brain

·         Localization of function refers to the idea that behaviour, emotion and thoughts originate in the brain in specific locations.

·         Different parts of the brain have different functions, this allows for the study of the relationship between the brain and behaviour.

·         Human understanding of brain localization has been improved as a result of more advanced technologies (scans)

Case Study:

·         Paul Broca (1824-80) studied a patient known by the name of ‘Tan’ as this was one of the only sounds he could make with frequency.

·         After Tan’s death, Broca ran an autopsy and provided new evidence that the area of the man’s brain which was damaged was responsible for the loss of ability to produce coherent speech.

·         This specific area is now called the Broca’s Area and the inability to produce coherent speech due to damage to this part of the brain is known as Broca’s Aphasia.

(Wernicke’s Aphasia is also a speech disorder which involves the Wernicke Area of the brain which is responsible for comprehension of speech. Proposed by Carl Wernicke)

Syllabus Question:  Using one or more examples, explain effects of neurotransmission on human behaviour.

·         Neurotransmitters are chemical messengers that send messages from one neuron to another.

·         When your brain is stimulated by the environment, it reacts by sending electrical impulses through your body to react.

·         The method of these impulses travelling is called neurotransmission. Electrical impulses travel down the axon which releases neurotransmitters that travel across the synapse junction and trigger of the next neuron. 

Examples of Neurotransmitters:

Acetylcholine	Results in muscle contraction and a role in the development of memory in the hippocampus
Dopamine	Results in voluntary movement, learning and feelings of pleasure.
Noradrenalin	Results in arousal, alertness and stimulation of the sympathetic nervous system.
Serotonin	Results in sleep, arousal levels and emotion

Acetylcholine

·         Functions: triggers muscle contraction and plays a role in memory formation

·         Too much = headaches, irritability, restlessness, insomnia, depression

·         Too little = difficulty remembering things, difficulty comprehending things, social withdrawal, lack of emotion and depression.

Case study conducted by Martinez and Kesner (1991):

·         Tested rats to see the effects of the neurotransmitter acetylcholine on memory formation of mazes in rats.

·         Rats were first trained to go through a maze, at the end of which they were given food as a reward.

·         A group of rats were then injected with scopolamine which blocks acetylcholine sires thus decreasing acetylcholine levels, another were injected with physostigmine which increased acetylcholine levels and the control group was injected nothing.

·         Results showed that rats injected with scopolamine were slower at finding their way through the maze and made more errors compared to the other two groups.

·         The group injected with physostigmine ran through the maze much quicker and made less errors.

·         This study showed the role of acetylcholine in memory functioning and the effect of neurotransmitters on human behavior and functions.

Serotonin

·         Functions: regulates mood, emotion, appetite, aggression and sleep

·         Too much = lowers stress levels

·         Too little = depression, anxiety, pessimism and aggression

Case study by Kasamatsu (1999)

·         Studied budhist monks in sensory deprivation

·         Monks were given no food, did not speak and were exposed to cold weather.

·         After 48 hours the monks began hallucinating.

·         Blood samples showed increased serotonin levels in hypothalamus and frontal cortex.

·         Was concluded that sensory deprivation triggered the release of serotonin (resulting in the hallucinations).

Syllabus Question: Using one or more examples, explain functions of two hormones in human behaviour.

·         Hormones are chemical messengers that are secreted by glands into the blood stream. The glands that release hormones are found in the endocrine system.

Adrenaline

·         Flight or fight response, adrenaline prepares the body to either fight the threat or run away from it.

·         Increases the flow of oxygen and blood to the brain by increasing heart activity and dilating blood vessels.

·         Released from the adrenal medulla of the adrenal gland, increases alertness.

Oxytocin

·         Love/trust hormone

·         Produced by physical contact

·         Produced during childbirth and breastfeeding

·         Social attachment

·         Human social bonding

Case Study by Morhen et al. (2008)

·         96 subjects were split into 3 groups: massage and trust, rest and trust and massage only.

·         Subjects then participated in a trust game.

·         Participants in the massage and trust group sent more money to others; increased generosity.

·         Concluded that Oxytocin increased generosity of participants, trust and cooperation in humans.

Melatonin

·         Secreted by pineal gland and effects circadian rhythm.

·         Is secreted during darkness.

·         It’s role is to ‘turn off’ the body. Sleep hormone.

·         Too little = Insomnia, depression, fatigue, anxiety

·         Too much = Seasonal affective disorder (SAD), feeling tired, lowered concentration, disturbance in diet.

Case Study by Charmane Eastman et al (1998):

·         Used light therapy and placebo on 96 patients suffering from SAD

·         Participants were exposed to light for 1.5 hrs a day at different times

·         Overall, found that exposure to light worked as an anti-depressant, helping those suffering from SAD.

Syllabus Question: Discuss two effects of the environment on physiological processes.

·         Behaviour and environment can change your brain.

·         Brain constantly changing as a result of experience.

Sleep-wake cycle

·         The effects of the environment on physiological processes include levels of light and melatonin secretion effect on sleep-wake cycle and seasonal affective disorder.

·         Melatonin plays a vital role in the cycle of sleep and is secreted by the pineal gland. It is produced during the absence of light.

·         Just use SAD case study.

Brain Plasticity

·         The brains ability to rearrange connections between neurons in the brain.

·         Brain adapts to the challenges of the environment.

·         Rich learning environment increase the density of neural connections.

·         Dendrite branching: Neurons connect to create a new trace in the brain.

Rosenzweig and Bennet (1972) Case Study

·         Placed rats in two environments; one was enriched with learning opportunities, the other deprived.

·         Rats stayed in for 30-60 days in their environments.

·         Looked at effects of enrichment and deprivation on the development of neural pathways.

·         Found that rats in stimulated environment increased thickness in cortex. Frontal lobe was heavier – thinking, planning, decision making area.

·         Relates back to brain development of humans.

Syllabus Point: Examine one interaction between cognition and physiology on behaviour. Evaluate two relevant studies

·         Humans are capable of influencing their cognitive processes (brain functions)

Case Study: Richard Davdison (2004)

·         Experiment involved 8 Buddhist monks, who were highly experienced in meditation, and 10 volunteers who had been trained in meditation for only 1 week.

·         Participants were told to meditate on love and compassion.

·         Using PET scans it was found that Monks experienced an increase in the number of gamma waves in their brain during the meditation.

·         Gamma waves related to higher reasoning faculties.

·         Once meditation was stopped, was found that gamma waves did not change in the monks brains, but were decreased in the inexperienced volunteers.

·         Davidson concluded that meditation has significant long-term effects on the brain and how we process emotions.

·          This indicates that the brain adapts to stimulation from environment or our own thinking.

Syllabus Question: Discuss the use of brain-imaging technologies in investigating the relationship between biological factors and behaviour

Functional MRI (fMRI)

·         Provides 3D pictures of the brain structures, using magnetic fields and radio waves.

·         Shows actual brain activity and indicates which areas of the brain are active when engaged in behaviour.

·         Higher resolution than PET scans. Most frequently used in biopsychological research.

Case Study: Natalie S. Wernerab (2009)

·         Aim was to investigate the hippocampal function in unipolar depression using fMRI.

·         11 unipolar depressed patients and 11 healthy participants underwent an associative learning paradigm during fMRI scanning.  Participants had to learn face-profession pairs.

·         Hippocampal activity didn’t differ between depressive and healthy patients.

·         There was increased activity in the left parahippocampal gyrus and decreased activity in the frontal and parietal regions in depressive patients.

·         Results are limited due to the small number of participants involved in the case study.

·         Conclusion: Suggests that depression is associated with modified memory-related brain function.

Electroencephalogram (EEG)

·         Developed at the beginning of the 20^th century named by Hans Berger in 1929

·         Electrodes are placed around the outside of a person’s head. Electrodes detect changes in electrical activity below them.

·         When areas of the brain are active, the EEG produces a graphical representation of the activity from each electrode.

·         Mainly used during sleep research.

·         Not very accurate as the electrodes are outside the skull and can only give a vague idea of what parts of the brain are active.

Computed Tomography (CT/CAT)

·         Combination of computer and X-ray technology.

·         Images acquired from the CT scan can be taken from top, bottom, back front and sides of the brain, showing the brain in-depth.

·         Images look like slices of the brain.

·         Are extremely useful in showing structural changes in the brain. E.g. brain tumors and brain damage are very evident on CT scans.

·         Limitation: Can only produce a structural image.

·         Case Study by Ogden (2005) found that a woman who died after developing a brain tumor. Janet (the woman) was found to have a brain tumor in the parietal lobe of her right hemisphere which was detected by CT. 

Positron Emission Tomography (PET)

·         Requires the injection of a radioactive substance into the participant. (usually form of sugar that produces gamma rays in the brain)

·         Similar to MRI in regards to the fact that parts of the brain that is being used lights up as these parts will metabolize the sugar initially injected at different rates.

·         The signal is converted into a computer image that displays a colourful map of activity in different parts of the brain.

·         PET is good for showing dynamic activity of the brain but is less precise than the fMRI. Useful for problems that do not involve structural changes in the brain.

·         Useful to show abnormalities in activity levels in the brain.

·         PET scan may not be advisable for patients with specific individual health problems.

Genetics and Behaviour

Syllabus Point: With reference to relevant research studies, to what extent does genetic inheritance influence behaviour?

·         Human beings reproduce sexually. Genetic information from two people come together and produces a fertilized egg. This accounts for a large number of inherited characteristics that the new organism has.

·         Genes are thought to be responsible for the development of physical and behavioural characteristics. Genetic make-up of a person is their genotype.

·         It is not only genotype but also external factors influence the way an organism develops.

·         Observable characteristics of an organism are their phenotype, which is a result of the genotype and environment interacting.

·         Clausen et al. (1948) conducted a famous experiment involving planting genetically identical yarrow plants at different altitudes.

·         The resulting phenotypes were quite different because of the differing environments the plants were growing in.

·         Though genes play a role in determining human behaviour and physical characteristics, other external factors, such as the environment in which one is brought up in, have an effect on the development of the human.

·         You can refer to the previously explained homosexual twin study here.

·         Although genes have some role in influencing behaviour, they do not work in isolation from each other and can also be affected by environmental factors.

Syllabus Question: Examine one evolutionary explanation of behaviour

·         Human behaviour would have evolved as a way to adapt to changes as time progresses.

·         Behaviour that has helped a species survive and reproduce is described as adaptive.

·         Key Assumption: Human behaviour must have been adaptive under some circumstances in the past.

Homicide as adaptive behaviour:

·         The homicide adaptation theory (HAT) is an example of an evolutionary psychology theory.

·         Theory suggests that humans have evolved with some psychological adaptations for killing.

·         This is an advantage in situations such as hunting for food to survive, defending resources, protecting one’s children and killing of rivals to increase one’s own chance of surviving and reproducing.

·         It is considered to be an adaptation based in increasing their own or their offspring’s chance of survival.

·         Durrant (2009) suggests that the proposed theory are not adaptations to increase one’s survival but are by-products of evolution, so perhaps, homicide has no advantage.

·          To test the theory of evolutionary psychology, a cost-benefit analysis can be run.

·         Durrant (2009) gives the example that attempting to kill someone will expose an individual’s own potential to cause harm that might result in their own death, which isn’t adaptive; therefore HAT is unlikely to be correct. (Costs outweigh the benefit)

Syllabus Question: Discuss ethical considerations in research into genetic influences on behaviour

Genetic Testing

·         Genetic tests can indicate whether an unborn baby will be born with diseases such as PKU which allow the parents to prepare for such circumstances.

·         As scientists delve into genes associated with risk of diseases and disorders, other information in regards to genetic heritage can also be uncovered.

·         Finding out about certain things which the individual would rather not know has a number of negative implications.

·         It also affects third parties such as insurance companies which may not be willing to insure certain individuals due to a genetic predisposition to a disorder of the person.

·         Employers may also not be willing to recruit these people to work.

·         For this reason, genetic testing requires consent from the person involved and those responsible for the person involved.

Research Findings

·         In the context of research, all findings regarding the participant should be accessible by the participant.

·         This poses the risk that a participant may find out things which they would rather not know about themselves as a result of research.

·         Counseling should be offered by the researcher.

·         Alternative research is that data should be anonymously coded so that neither the researcher nor the participant knows which results match which specific DNA sample.

·         Another ethical issue is the interpretation of research findings.

·         Tend to lack in causal evidence s a result of lacking the possibility to experiment for ethical reasons.