3B Self: Biological Influences

Question 1

What is the Central Nervous System composed of and what does it do?

Answer 1

• The brain & spinal cord

- It receives and interprets sensory information sent from the PNS and transmits motor messages to the PNS

Question 2

What is the Peripheral Nervous System composed of and what does it do?

Answer 2

• All the nerves that extend from the brain and spinal cord

- Carries information between the Central Nervous System and the rest of the body

Question 3

What are the two divisions of the Peripheral Nervous System and what are they responsible for?

Answer 3

• Somatic Nervous System: conveys sensory information to the CNS and motor messages to the muscles
• Autonomic Nervous System: serves to regulate basic life functions, e.g. respiration, heart rate, blood pressure, digestions, and is at work when we experience fear or stress

Question 4

What are the two divisions of the autonomic nervous system and what do they do?

Answer 4

• Sympathetic Nervous System: dominates when under fear/stress, triggers the fight/flight response. Arouses the body through pupil dilation, slowed digestion, release of endorphins to prepare for injury and change in galvanic skin response
• Parasympathetic Nervous System: Maintains the steady state of balanced normal functioning, counteracts the SNS. Restores the body to calmness after threat, decreases heart rate, contracts pupils etc.

Question 5

What is the frontal lobe known as and what are its functions?

Answer 5

• Known as the primary motor cortex
• Functions include the most complex mental behaviours (thinking, analysing, problem solving, memory, learning), and the control of voluntary movement

Question 6

What may happen if the frontal lobe is damaged?

Answer 6

The individual may experience a change in personality or emotional life

Question 7

What special area is contained in the frontal lobe and what is it responsible for?

Answer 7

• Broca’s area

- Responsible for the formation of language: controls muscles of throat, mouth, jaw, tongue and face

Question 8

What is the parietal lobe known as and what are its functions?

Answer 8

• Known as the primary somatosensory cortex
• Functions include sense of touch, motion detection in the environment, location of objects in space and experiencing one’s own body as it moves through space. Also important for processing any sensory information (touch, temp, pressure)

Question 9

What is the occipital lobe known as and what are its functions?

Answer 9

• Known as the primary visual cortex
• Functions include the processing of visual information (seeing different colours, perceiving and recognising different objects, animals and people)

Question 10

What is the temporal lobe known as and what are its functions?

Answer 10

• Known as the primary auditory cortex
• Functions include the processing of all auditory information, memory, facial recognition, object identification and emotion

Question 11

What special area is contained in the temporal lobe and what is it responsible for?

Answer 11

• Wernicke’s Area

- Responsible for the comprehension of speech and formulation of sentences

Question 12

What is an EEG, what can it detect and what are it’s advantages and limitations?

Answer 12

• Electroencephalography: device which detects, amplifies and records electrical activity of neurons. Produces a recording of brainwave patterns to be analysed and intepreted to assess brain functioning
• Can detect tumours, epilepsy and sleeping problems
• Advatanges: painless/harmless, non invasive, less expensive
• Disadvatanges: doesn’t show source of brain activity, only provides and overview of activity, recording of activity is weaker than actual brain activity itself

Question 13

What is a CAT scan, what can it detect and what are it’s advantages and limitations?

Answer 13

• Computerised Axial Tomography: scanned image which is turn into a 2D image of the brain, shows structure of the brain where it can identify the difference between healthy and abnormal brain tissue
• Can detect tumours, strokes and other injuries
• Advantages: One of least expensive brain research methods, considered non-invasive
• Limitations: Exposure to radiation, provides information about brain structure but not activity

Question 14

What is a MRI, what can it detect and what are it’s advantages and limitations?

Answer 14

• Magnetic resonance imaging: uses large magnets to create a magnetic field (where different types of tissue react differently to the magnetic field), produces a very detailed image of the brain
• Can detect tumours and abnormalities
• Advantages: Better shows difference between healthy and abnormal brain tissue, non invasive, no harmful exposure to radiation
• Limitations: No info about brain activity, expensive, individuals with pacemakers cannot use due to magnets

Question 15

What is a fMRI, what can it detect and what are it’s advantages and limitations?

Answer 15

• Functional Magnetic Resonance Imaging: Measures brain function by identifying when neurons are consuming oxygen, the higher the brain activity, the bolder the image will show in the area
• Can detect visual processing problems, reading problems and other cognitive activities
• Advantages: clearly displays active areas of the brain, non invasive and no exposure to radiation
• Limitations: most expensive, and small movements made by participants can affect the results

Question 16

What is a PET scan, what can it detect and what are it’s advantages an limitations?

Answer 16

• Positron Emission Tomography: measures glucose consumption of the brain by monitoring the amount of brain activity that occurs while a participant is undergoing a task. Requires a radioactive injection of glucose, where a PET scan can show which areas of the brain are using more energy(consuming more glucose)
• Can detect areas of the brain linked with reading and math, tumours and other damage
• Advantages: shows source of brain activity and area of brain that is damaged
• Limitations: Considered invasive due to glucose injection, exposure to radiation, and no detailed images of brain structure

Question 17

Explain the case study of Phineas Gage in relation to damage of the frontal lobe.

Answer 17

• Suffered an accident at 4:15pm on the 13th of September 1848
• Filled a deep narrow hole with gun powder
• Rammed a long iron rod into powder where sparks ignited the powder, sending the rod shooting out of the hole
• The rod shot straight through Gage’s skull (penetrating the frontal lobe)
• He survived, but his personality completely changed due to the damage to his frontal lobe

Question 18

Explain the significance of doing brain research on animals instead of humans.

Answer 18

• By studying animals, we can make predictions about brain function and behaviour in humans and can generalise the results to humans
• Researchers can easily manipulate and control the environments of animals to study and see the effects of change
• It is unethical to do these types of research on people

Question 19

Describe the study of Ablation by Karl Lashley

Answer 19

• Surgically removed part of rat’s brains and found that he could not find one single biological area for memory
• Suggested that memories were not localised, but widely distributed throughout the cerebral cortex
• Proved that the brain was more complex than initially thought

Question 20

Describe the study of Lesions by Sperry

Answer 20

• Where the area of interest in the brain is destroyed or stimulated to observe any resulting changes
• Found that the two hemispheres of the brain each contain consciousness
• Showed lateralization of the brain: each hemisphere is responsible for performing different tasks

Question 21

Describe the procedure of electrical stimulation

Answer 21

• The use of multiple microelectrodes in specific locations of the brain, where weak electrical currents were used in short pulses intended to mimic the natural flow of impulses through the neutral pathways

Question 22

What did James Olds and Peter Milner discover in relation to electrical stimulation in animal studies?

Answer 22

• Discovered that a rat would press a bar to receive a brief impulse of electricity through an electrode implanted in certain areas of the brain
• Claimed to have beneficial effects in conditions such as anxiety, depression, insomnia and stress