Biological Flashcards
Where is the Frontal Lobe? What is its function?
Behind Forehead. Controls the person’s personality, emotions and behaviour and is involved in intellectual activities such as planning and organisation.
Where is the Temporal Lobe? What is its function?
Behind the ears. It holds the bulk of our memories and our ability to understand and speak.
Where is the Parietal Lobe? What is its function?
Top back of the brain. It is responsible for our perception and spatial awareness as well as manipulating objects and spelling.
Where is the Occipital Lobe? What is its function?
Back and bottom of the brain. It’s responsible for sight.
What does the Cerebellum control?
Muscle movement, balance and coordination.
What does the Brain Stem include? What does it control?
Midbrain, Medulla, Pons. Controls breathing, heart rate, consciousness, blood circulation, basic motor responses. Relays sensory information and regulates the sleep-wake cycle.
What is a Vesicle?
Tiny sacs that contain molecules of neurotransmitter chemicals.
What is a Neurotransmitter?
Chemicals that pass messages between neurones.
What are Receptors?
Sites on dendrites that are designed to bond to and absorb a specific type of neurotransmitter molecule.
What is Neurotransmission?
Process by which one neurone communicates with another.
Describe the process of neurotransmittion
An electrical impulse travels along the presynaptic neuron
The impulse reaches the synaptic vesicles to release a neurotransmitter
These diffuse across the synaptic gap and attach receptors
Recreational Drugs
Increase or decrease neurotransmitters at the synapse
Increase levels of dopamine so user experiences euphoria or pleasure
Decrease synapses efficiency so neurotransmission is affected.
Become addictive and quitting leads to withdrawl.
Cocaine
Uptake triggers dopamine instantaneously
Increases alertness
Blocks binding site on presynaptic neuron
Which prevents reuptake of dopamine
Degrades synapses overtime
Alcohol
Blocked reuptake - receptors, transmission, pre-frontal cortex, sensory perception
Increased GABA - dopamine, relaxation
Amygdala
Link between the amygdala in the prefrontal cortex
Roll in aggression is unclear but significant
Prefrontal cortex and Amygdala
Prefrontal cortex regulates emotional responses driven by amygdala
Damage result in impulsivity, immaturity and loss of control
Phineas Gage (1848)
Had an accident at a railway
Iron pole went through his prefrontal cortex
Behaviour changed completely + had huge increase in aggression
Raine et al (1997)
Investigated brain activity of 41 murderers
Using PET scans
Found reduce glucose metabolism in prefrontal cortex
Suggesting brain is less active + efficient
Endocrine system
Triggers glands to produce hormones
Neurotransmitters V hormones
Neurotransmitters travel tiny distances + take affect in fraction of a second
Hormones travel by bloodstream and take affect more slowly, when hormones reach target cell the bind to a cell + change its function
Hypothalamus
Part of limbic system
Homeostasis
keeps track of hormone production and regulating it

Testosterone
Key hormone linked to aggression
Produced in spurts so levels can differ
 linked to dominance in animals + can vary seasonally
Males produce more testosterone + that correlates with why men are more aggressive
Wagner et al (1979)
Castrated mice + observed that aggression levels dropped
When injected with it previous back to pre-castration testosterone + aggression levels
Direct correlation but can’t be generalised to humans
Dabbs et al (1995)
Measured testosterone levels of saliva of 692 adult male prisoners
Found a higher levels in violent offenders described as tough
fMRI
Detects changes in blood oxygenisation + flow that occurs in the brain. More active = consumes more oxygen so blood flow increases
Advantages of fMRI
Non-invasive, can see brain activity, high resolution, valid, widely used + standardised, imperial data can be peer reviewed so reliable
Disadvantages of fMRI
Needs interpretation, can produce false positives, very noisy, not reliable
PET
Scanner detects radioactive material that is injected or inhaled as glucose that travels + accumulates around the body. Where metabolism is active, radioactive substances break down + release neutrons + gamma rays which are detected
Advantages of PET
Detects brain activity, valid, reliable, ethical
Disadvantages of PET
Needs interpretation as its difficult to isolate brain functioning, claustrophobic, expensive, invasive(injection)
CAT
Uses a series of x-ray beams passed through the head, creating a cross-sectional image of the brain showing its structure
Advantages of CAT
Non-invasive, safe + painless, valid, reliable, doesn’t need interpretation, produces detailed pictures
Disadvantages of CAT
Can’t see brain activity, may need injection(dye to show blood flow),
MRI
Uses detection of radio frequency signals produced by displayed radio waves. Shows organs + blood flow if a control medium(dye) is injected
Advantages of MRI
Non-invasive, reliable, valid, safe + painless, no preparation needed
Disadvantages of MRI
Can’t see brain activity, needs interpretation, noisy + claustrophobic
Monozygotic
1 egg splits into 2, 100% genetically similar
Dizygotic
2 eggs, 50% genetically similar
Brendgen contemporary study (2005)
To see if there is a genetic relationship for physical and social aggression in 6 yr old twins by surveying their teachers + classmates
Brendgen’s sample
Mean age of 72 months (6yrs)
MF - 50, MM - 44, DF - 32, DM - 41, mixed - 67
Large sample size
2 reasons to why you use Spearman’s rho
To test for a correlation
It uses ordinal data
