Week 1

Question 1

What is neuroscience?

Answer 1

scientific study of the nervous system, which controls behaviour

• interdisciplinary
• BPS fundamental

Question 2

Central nervous system (CNS)

Answer 2

• brain
• spinal cord

Question 3

Peripheral Nervous system (PNS)

Answer 3

Nerves (Cranial and spinal)

Ganglia (a mass of nerve cell bodies)

Question 3

Neurones

Answer 3

Building block of the nervous system

• dendrite: receives the AP
• Myelin sheath - Insulates AP
• Nodes of Ranvier - where the AP travels (saltatory conduction)

Question 4

Why is NS an essential subject to pscyhology?

Answer 4

Behaviour is initiated in the nervous system

Question 5

Psychologists who study biological bases of behaviour name?

Answer 5

Behavioural neuroscience

Question 6

History of neuroscience

Answer 6

1) historical notions

2) Evolution

3) brain evolution

Question 7

1) Human prehistory (2.5 million years ago)

Answer 7

• stone age, bronze age, iron age, neolithic period
• blunt force cranial trauma (on right = effects left side of body = brain works counterlaterally)
• cranial trepanation
  • “5-10% of all skulls found from the Neolithic period were trepanned with single or multiple skull openings of various sizes”
  • Drilled holes in heads
    ○ Release of evil spirits?
    ○ Alleviation of pressure on brain?

Question 8

Ancient Egypt

Answer 8

• Earliest written reference to the brain (17th Century BCE) – the Edwin Smith Surgical Papyrus - doctors of the brain used to operate on the brain and write their methods
  
  • Believed the heart to be the control of function surprisingly
    Body and most organs were preserved (mummified) after death… but not the brain

Question 9

Ancient Greece

Answer 9

• Hippocrates (c. 460-377 BCE) the theory of the four humours “… the source of our pleasure, merriment, laughter and amusement, as of our grief, pain, anxiety, and tears is none other than the brain” ‘father of medicine’
  
  • Yellow bile, black bile, phlegm & blood = humours
    = Acknowledges importance of brain
  • Aristotle (384-322 BCE) “… the brain is not responsible for any of the sensations at all, the correct view is that the sear and source of sensation is the region of the heart”
    (Also Socrates & Plato)

Question 10

Roman Empire

Answer 10

Galen (130-200 CE)

• saw the brain as the ruling organ of the body
  
  • Common sense, cognition and memory were all functions of the brain
• Discovery of ventricles fitted with Hippocrates’ theory of humourism

Question 11

The dark ages (~500-1000 AD)

Answer 11

• Nothing documented
  Beginning of christianity in western world

Question 12

The Renaissance (3 significant people)

Answer 12

• Leonardo Da Vinci
• Andreas Vesalius
• Rene Descartes

Question 13

Da Vinci (1452-1519)

Answer 13

• Sensation, cognition and memory attributed to the “3” ventricles
  
  • Drawings of the brain, nervous system

Question 14

Vesalius (1514-1564)

Answer 14

• Added more detail to the understanding of brain structure
  Found errors in Galen’s anatomy (e.g. blood does not flow from the left to the right side of the heart)

Question 15

Descartes (1596-1650)

Answer 15

• Fluid-mechanical theory of brain function
  
  • Reflexive theory (realised reflex was not controlled by the brain)
  • Dualism (the mind and the body are one, pineal gland - communicating with the ‘spirits and gods’ which then control the body)
    ‘ I think therefore I am’

Question 16

The 19th Century: 4 key insights…

Answer 16

1) Nerves and Wires

2) Localisation of specific brain functions

3) the neuron

4) Evolution of the brain

Question 17

Nerves are wires: Luigi Galvani (1737-1798)

Answer 17

• Stimulation of nerves in frogs caused muscle contractions
  Major finding - an electrical process

Question 18

Nerves are wires: Hermann von Helmholtz (1821-1894)

Answer 18

• Human physiology is subject to the laws of nature
  
  • Measured the speed of nerve conduction
    ○ * ~90 ft/sec
    ○ * Slow – not just electrical, but physiological
    e,g, used eals

Question 19

Localisation of specific brain functions: Johannes Müller (1801-1858)

Answer 19

• Proposed the “law of specific nerve energies”
  
  • Neurones are the same but they go to different parts of the brain (e.g. optical vs auditory nerves)

Question 20

Localisation: Marie-Jean-Pierre Flourens (1794 1867)

Answer 20

• Experimental ablations (electrical stimulation = knock out part of the brain)
  = different effects all over the body of animals
  
  • • Intellect = cerebral cortex
  • • Lower brain = vital bodily functions
• Cerebellum = coordination and motor control

Question 21

Localisation: Paul Broca (1824-1880)

Answer 21

• Damage to left frontal cortex = difficulties in language production
  
  • Broca’s region - language production

Question 22

Localisation: Gustav Fritsch & Eduard Hitzig

Answer 22

• Muscle contractions contralateral to brain hemisphere
  Nailed down & confirmed the contralateral workings of the brain - the left hemisphere controls the motor functioning of the right side of the body…)

Question 23

3. The neuron

Answer 23

• The basic functional unit of the brain

Camillo Golgi (1843-1926)
- Invented a new staining technique
-  Propose “reticular theory”
○ Golgi staining/ golgi cell….

Santiago Ramón y Cajal (1852-1934)
- Worked out neural circuitry of many brain regions
- Propose the “neuron doctrine” - building blocks
- The basic functional unit of the brain, interconnected by chemical synapses (NTS)

Question 24

Evolution: What is evolution? Darwin & Wallace

Answer 24

Charles Darwin (1809-1882) “On the origin of species” (1859) considered the foundation of evolutionary biology  Natural selection - different genomes & then mutations = ^ survival  Evolution: Gradual change in structure of physiology of a species – generally producing more complex organisms – as a result of natural selection Natural selection theory can be attributed to Charles Darwin AND Alfred Russel Wallace  Wallace had the idea during a fever in 1858  However, Darwin had been working on it for 20 years in private e.g. the pepper moth

Question 25

Brain evolution: Vertebrate brains

Answer 25

- Vertebrate brains are similar in organization (frogs, crocodiles, sharks…) - All vertebrates have a forebrain, midbrain & hindbrain (but do have other nuances) -  Brain areas may be specialised in distinct ways in response to environmental constraints * e.g., crocodiles have huge olfactory bulbs (brain area for smell)

Question 26

How have human brain size incrreased?

Answer 26

 Proportion of the different areas changed (e.g. prefrontal cortex to accommodate more complex interactions)  Folding of cerebral cortex increased

Question 27

Bigger brain = higher behavioural complexity?

Answer 27

there is no link between brain size and behavioural complexity (e.g. how elephants have bigger brains) BODY SIZE PROPORTIONS MATTER. -  There is a relationship between proportional brain size and complexity of behaviour  Human brain is proportionally larger than any other large animal (although Shrew's have 3.3% of their body as brains...)

Question 28

Evolution of Hominids (See image)

Answer 28

○ 1. Australopithecus robustus  2. Homo habilis  3. Homo erectus  4. Homo sapiens neanderthalensis  5. Homo sapiens sapiens The high, straight forehead of modern humans superseded the prominent brow ridges of ancestors due to expansion of cortex, especially prefrontal cortex, in our species

Question 29

The neocortex (most changes here)

Answer 29

- Size increased in primates -  Is flexible & has almost infinite learning abilities -  Reflects growing complexity of social lives  Growth of certain parts of cortex responsible for social skills (e.g., language) because they improved this ability (includes all the lobes)

Question 30

The prefrontal cortex

Answer 30

- Developed greatly in primates -  In other species it is primarily for voluntary motor control -  In humans: Responsible for unequalled planning & abstract reasoning abilities MODERN RESEARCH:  Humans’ superior abilities are attributable to other specialized cortical regions & denser inter-connections between prefrontal cortex & rest of brain

Question 31

Why is our prefrontal cortex so big compared to other primates?

Answer 31

Humans have larger volume of white matter in PFC White matter provides greater connectivity between PFC & rest of brain (compared to other species) Connectivity is vital for working memory functioning

Question 32

Increased folding of cerebral cortex

Answer 32

Increase in cortex folding has been a major factor in brain evolution Folding = cortical surface area to fit inside the skull Allows better organization of complex behaviours

Question 33

Reading: Epigenetics

Answer 33

Changes to gene expression induced by environmental factors.

Question 34

Reading: Functionalism

Answer 34

The principle that the best way to understand a biological phenomenon (a behavior or a physiological structure) is to try to understand its useful functions for the organism.

Question 35

Reading: Natural selection

Answer 35

The process by which inherited traits that confer a selective advantage (increase an animal’s likelihood to live and reproduce) become more prevalent in a population.

Question 36

Reading: Mutations

Answer 36

Can be beneficial - variety is an advantage for species; adaptation

Question 37

Reading: What percentage of the human body is the brain?

Answer 37

human - 2.3% Elephant - 0.2% Shrew - 3.3% What counts, as far as intellectual ability goes, is having a brain with plenty of neurons that are available

Question 38

Reading: neoteny

Answer 38

A slowing of the process of maturation, allowing more time for growth; an important factor in the development of large brains.