I reccomend psychology IB students to see this presentation. Hello, In this presentation you will find the Biological Level of Analysis (BLA) broken down into its different sections: principles, studies supporting principles, research methods used in BLA, ethical considerations, localisation of function, neurotransmitters, hormones, effects of the enviornment on physiological processes, interaction between cognition and physiology, brain imaging technologies, genetic inheritance, evolutionary explanations of behaviour and ethical considerations of genetic research. I hope you find it useful! Good luck to everyone

1. Carlos Cardini May

2. Table of contents
 Principles
 Studies supporting principles
 Research methods used in the biological level of analysis
 Limitations in research methods
 How to overcome limitations
 Ethical considerations
 Localisation of function
 Neurotransmitters
 Hormones
 Effects of the environment on physiological processes
 Interaction between cognition and physiology
 Brain imaging technologies
 Genetic inheritance
 Evolutionary explanation of behaviour
 Ethical considerations of genetic research

3. Principles
1. Patterns of behaviour can be inherited.
2. Animal research may inform our understanding of
human behaviour.
3. Emotions and behaviours are products of the
anatomy and physiology of the nervous and
endocrine systems.

4. 1. Behaviour can be inherited.
 Garcia et. al (2010).
 Aim: Associations between Dopamine D4 Receptor Gene
Variation with Both Infidelity and Sexual Promiscuity.
 Procedure: They surveyed 181 young adults regarding their
intimate lives and obtained a DNA sample from each
participant.
 Findings: Participants with 7 repetitions of DRD4
correlated with 50% more situations involving infidel or
promiscuous behaviour than to those with less than 7R.
 Conclusions: DRD4 plays an essential role in promiscuous
and infidel behaviour.

5. 2. Animal research may inform our
understanding of human behaviour.
 Martinez and Kesner (1991)
 Aim: Determine the role of acetylcholine on memory.
 Procedure: Rats were trained to go through a maze, they
were given food at the end. 3 groups: 1) Injected with A.C.
receptor blockers and therefore decrease levels of A.C. 2)
Injected to prevent A.C. being reabsorbed. 3) Control
group.
 Findings: Group 1 was the slowest and group 2 the fastest.
A.C. improves memory of rats: they resolved the maze
faster and with less errors in comparison to rats that had
normal or low levels of acetylcholine in the synaptic gap.
 Conclusion: There is a clear correlation between
acetylcholine and memory.

6. 3. Emotions and behaviours are products of the
anatomy and physiology of the nervous and
endocrine systems. Raine et. Al (1997)
 Aim: (using PET scans) discover if murderers who pleaded not guilty
by reason of insanity (NGRI) showed evidence of brain abnormalities
(observing the cortical and sub cortical parts of the brain)
 Procedure: 41 participants (39 male, 2 female) who pleaded not guilty
for reasons of insanity (average age of 34.3) 41 participants (controls),
selected based on sex, age and matched to a NGRI participant. Each
participant was injected with a glucose tracer to measure brain activity.
They had to perform tasks requiring them to detect target signals for 32
minutes
 Results: NGRIs had less activity in the pre-frontal cortex (linked to
self-control and emotion). NGRIs had lower activity in the amygdale
and medial temporal hippocampus. Lack of inhibition of violent
behaviour. Fearlessness - Inappropriate emotional expression. Failure
to learn consequences for violence.
 Conclusion: There is a difference in brain structure between normal
subjects and prisoners that pleaded not guilty for reasons of insanity

7. Research methods in BLA
 Experiments: laboratory
experiment, natural experiment
and field experiment. [Outline
APFC of experiments such as
Rosenzweig and Bennett (1972),
Raine (1997), Berthold (1849)]
 Case studies. [Outline APFC of
experiments such as Harlow –
Phineas Gage (1848), Broca – “Tan”
etc.]

8. Limitations of research methods
 Confounding variables – uncontrolled
variables that influences effect sought.
 Demand characteristics – participant
knows what it is expected from him.
 Research bias – the research sees what
they are looking for and consciously or
unconsciously affects the findings.
 Observer bias (Hawthorne effect) –
participants act differently due to the
consciousness of being observed by
people.

9. How to overcome limitations
 Triangulation – use 2 or more research methods of
investigation to explore the same aspect
 Single blind procedure – where participants do not
know which treatment they recieved.
 Double blind procedure – where neither participants
or researchers know which treatment participants
have recieved

10. Ethical considerations
 6 Ethical concerns:
 Informed consent is mandatory.
 Withdrawal – Right to withdraw is obligatory.
 Deception – Intentional deception must be avoided.
 Debriefing – Participants must leave the experiment in
the same mental state.
 Protection of participants – There should not be any
physical or mental harm.
 Animal ethics – Welfare of subjects is compulsory.
 Studies with ethical concerns (i.e. Rosenzweig and
Bennett (1972), Berthold (1849), etc).

11. Localisation of function
 Studies supporting localisation of
function:
 Broca – Tan (1861)
 Harlow – Phineas Gage (1849)
 Raine et al. (1997)
 Roger Sperry (1968)
 Wernicke (1874)
 Milner – HM (1966)

12. Sperry (1968)
 Aim: To investigate localisation and laterization of brain function. Test the
effects of a severed corpus callosum, prove that the two hemispheres have
different functions.
 Procedure: 11 patients with severed corpus callosum were asked to perform
hemisphere-related tasks. The tasks included being shown an image on the left
or right visual field and then identify or draw the pictures with their left or
right hands.
 Findings: Patients could redraw pictures only with left hand (right hemisphere
is linked to spatial awareness. If shown to left eye, participants could not name
the object but could pick it out physically (and vice versa).
 Conclusions: Each hemisphere of the brain has different functions: the left
brain is dominant in language and mathematical abilities while the right is
dominant in visuo-spatial, musical and understanding intonation speech
abilities.
 Limitations: Participants suffered from epilepsy and severed corpus callosum
-> not generalisable. Small population of participants (11). Low ecological
validity.

13. Neurotransmitters
 Acetylcholine – development of memories (Martinez
and Kesner) and muscle contraction.
 Dopamine – learning, feelings of pleasure. Associated
with reward-seeking behaviours and addiction.
 Noradrenaline (norepinephrine) – arousal, alertness,
stimulation of the sympathetic nervous system.
 Serotonin – involved in sleep, arousal and levels of
emotion. High levels linked to hallucinations
(Kasamatsu and Hirai. [1999]). Low levels linked to
OCD (SRI theory) and depression (Davison and Neale
[2001].

14. Hormones
 Oxytocin (released when
hugged or romantically loved.
Counteracts social anxiety.
 Melatonin (fight jet lag)
 Adrenaline (Schater and
Singer [1962] demonstrated
the effect of emotion with
increased adrenaline: anger
and euphoria)
 Testosterone (Berthold [1849]
showed that castrated roosters
were less masculine. Dabbs et.
al (1995) sexual criminals had
significantly higher
testosterone levels than
property criminals.

15. Effects of environment on
physiological processes part 1
 Brain plasticity: rearranging connections with
neurons as a result of learning or environment.
 Rosenzweig & Bennet (1972) compared 2 groups of
rats: 1) stimulating environment with toys. 2) Deprived
environment with no toys. Rats in stimulating
environment had a thicker cortex and heavier frontal
lobe (associated with thinking, planning, etc.)
 Another study: Analysed gamma rays of Buddhist
monks and control participants meditating on love and
compassion. Monks showed higher levels of gamma rays
which did not decreased; control group gamma rays
decreased.

16. Effects of environment on
physiological processes part 2
 Mirror neurons: A neuron fires when an animal or
human performs an action or when the animal
observed someone else perform the same action.
Discovered accidentally by Rizzolatti.
 Iacoboni (2004): Participants looked at faces while in
an fMRI, participants had to imitate the faces shown and
then they watched the faced again. The same areas of
the brain was activated both times and the limbic
system was stimulated.
 Simmon et al (2006): The same neurons fire in
response to pain are also fired when a person saw
someone else in pain.

17. Interaction between cognition and
physiology
 Cognition is the mental process of acquiring and
processing knowledge and understanding through
thought, experience and the sense. One of these processes
is amnesia (the inability to learn new information or
retrieve info that has already been stored [anterograde and
retrograde amnesia]).
 Clive Wearing (2007): Clive was a musician who got a viral
infection and had serious brain damage in the hippocampus
which resulted in memory impairment. He could not transfer
info from STM to LTM but he was still able to talk, read, write,
etc.
 H.M. (1957-97): Fell of a bicycle when he was 9, he had major
seizures by the time he was 16. Surgery was done to alleviate
seizures, tissue from temporal lobe removed (including
hippocampus) In 1997, MRI showed brain damage was
pervasive and included the hippocampus, amygdale, etc. In
conclusion, the hippocampus is needed to transfer memories
to the LTM.

18. Brain imaging technology
 Technology
 PET: Positron Emission Topography
 MRI: Magnetic Resonance Imaging
 fMRI: functional Magnetic Resonance Imaging
 EEG: Electroencephalogram
 CAT: Computerised Axial Tomography
 Studies:
 Fisher et al (2005) used fMRI’s and found that when a person is
showed the picture of loved ones, certain areas of the brain became
active (frontal, temporal and occipital lobes).
 Tierney et al (2001) used PET scans and found that the right
hemisphere was more active than the controls’ during the
production of both speech and sign language.
 Raine et al (1997) PET scan experiments that investigated the result
of brain damage on behaviour in murderers who pleaded NGRI.

19. Genetic Inheritance
 Certain behaviours can be inherited, see: Bouchard and McGue
(1981), Minnesota Twin Study (1990), Shields (1962), Garcia et al
(2010), Nurnberger and Gershon (1982), etc.
 For example: Garcia et. al (2010).
 Aim: Associations between Dopamine D4 Receptor Gene Variation
with Both Infidelity and Sexual Promiscuity.
 Procedure: They surveyed 181 young adults regarding their
intimate lives and obtained a DNA sample from each participant.
 Findings: Participants with 7 repetitions of DRD4 correlated with
50% more situations involving infidel or promiscuous behaviour
than to those with less than 7R.
 Conclusions: DRD4 plays an essential role in promiscuous and
infidel behaviour.
 Limitations: Culturally bias. Small sample. Ethical concerns -> self
fulfilling prophecy and mental distress.

20. Evolutionary explanation of
behaviour
 In the first trimester of pregnancy, hormones lower women’s
immune system so that it does not fight the new genetic material
in the womb.
 Fessler (2006) argues that the emotion of disgust helps to
compensate for the suppressed immune system.
 He found that women in their first trimester of pregnancy would
score higher in disgust sensitivity than women in the second and
third trimesters. Through natural selection, the trait of being
pickier with food compensated for increase susceptibility to
diseases and our ancestors managed to produce offspring.
 Curtis et al. (2004) found something similar: he asked
participants to rank their level of disgust of 20 images (7 pairs
were harmful to the immune system). He found that the disgust
reaction was strongest for images which threatened the immune
system.

21. Ethical considerations of genetic
research
 Nurnberger and Gershon (1982) found that major depressive disorder
was consistently higher for monozygotic twins (MZT) than dizygotic
twins.
 Ethical considerations:
 May cause the participants stress.
 Self fulfilling prophecy: If a MZT twin exhibits symptoms of depression, the twin
might have them as well.
 Stigmatisation
 Lack of informed consent
 Dr. Money (1974).
 Ethical considerations
 Lack of genetic research consent
 Lack of informed consent of participants parents
 Deception of participants
 Lack of debriefing
 Violated confidentiality
 Stigmatisation