COGNITIVE NEUROSCIENCE
SPECIALISATION SUMMARY
SUPPLEMENT
Cognitive Neuroscience: The Biology of the Mind (4th Edition)
2017/2018
INTERNATIONAL BACHELOR IN PSYCHOLOGY (IBP)
,A Brief History of Cognitive Neuroscience – Chapter 1
Thomas Willis: coined the term neurology, first anatomist to link abnormal human behaviour
to changes in brain structure
Cognitive Neuroscience: cognition (process of knowing – what arises from awareness,
perception, and reasoning), neuroscience (study of how the nervous system is organized and
functions)
Central issue: whether the mind is enabled by the whole brain working in concert or by
specialised parts of the brain working at least partly independently
Gall: If a person uses one function with greater frequency, the part of the brain representing
the function would grow, this would cause a bump in the overlying skull (anatomical
personology/phrenology)
Flourens: first to show that certain parts of the brain were responsible for certain functions –
aggregate field theory (whole brain participates in behaviour)
Localizationism – localized brain functions
John Hughlings Jackson: topographic organization in the cerebral cortex, later verified by
Wilfred Penfield
Brodmann: analysed cellular organization of the cortex, 52 distinct regions
(cytoarchitectonics)
Golgi: developed silver method for staining neurons – la reazione nera (‘the black reaction’)
Ramon y Cajal: neuron doctrine (nervous system is made up of individual cells)
Rationalism: Englightenment, all knowledge could be gained through the use of reason alone
Empiricism: all knowledge comes from sensory experience
Associationism: aggregate of a person;s experience determines the course of mental
development (Ebbinghaus, Thorndike, Watson – blank slate)
Miller: learning theory (associationism, Skinner) could in no way explain how language was
learned
Berger: recordings of a human brain’s electrical currents, 1929 – electroencephalogram
Hounsfield: performed the first computerized axial tomography (CAT) scan in 1972
Magnetic resonance imaging (MRI) based on nuclear magnetic resonance, first described by
Rabi in 1938
BOLD (blood oxygen level-dependent) contrast led to development of functional magnetic
resonance imaging (fMRI)
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, Structure and Function of the Nervous System – Chapter 2
Neurons: basic signalling units that transmit information throughout the nervous system
Glial cells: nonneural cells, structural support, electrical insulation, modulating neuronal
activity
Soma (cell body) – metabolic machinery suspended in cytoplasm
Dendrites – branching extensions, receive input from other neurons, spines – little knobs
attached by small necks to the surface of dendrites
Axon – single process that extends from cell body, output, many wrapped in fatty substance
(myelin), gaps in myelin layers – nodes of Ranvier
Transmission occurs at the synapse
Axon collaterals can transmit signals to more than one cell
Most neurons are both presynaptic (axons make a connection to other neurons) and
postsynaptic (other neurons make a connection to their dendrites)
Energy = electrical potential across the neuronal membrane (difference in voltage across the
neuronal membrane), resting state – inside of the neuron more negatively charged than the
outside (-70mV = resting potential)
Lipid membrane blocks the flow of water-soluble substances between the inside and the
outside of the neuron
Transmembrane proteins:
Ion channels: proteins with a pore through their centres, allow certain ions to flow down
their concentration gradients – selective for either sodium, potassium, calcium, or chloride
ions – selective permeability
Gated ion channels: capable of changing their permeability for a particular ion
Non-gated ion channels: unregulated, ion can always pass through
Ion pumps (active transport proteins): use energy to transport ions across the membrane
against their concentration gradients – combats drive toward equilibrium – move three Na+
ions out of the cell and two K+ ions into the cell
Passive current conduction = electrotonic conduction/ decremental conduction
Action potential: rapid depolarization and repolarisation of a small region of the membrane
caused by the opening and closing of ion channels, can travel for metres with no loss in in
signal strength (signal is continuously regenerated)
Spike-triggering zone in axon hillock initiates the action potential
Threshold for initiating an action potential = -55mV (depolarized membrane potential)
Threshold reached: voltage-gated Na+ channels open and Na+ flows rapidly into the neuron
(Hodgkin-Huxley cycle, self-reinforcing, 1ms) – voltage-gated K+ channels open, begins to
shift membrane potential back toward resting potential
Equilibrium potential = no net flux of ions – membrane temporarily hyperpolarised (around
-80mV) – during hyperpolarisation: voltage-gated Na+ channels are unable to open and
another AP cannot be generated (absolute refractory period), followed by relative refractory
period, can generate AP but only with larger-than-normal depolarizing currents
Consequences of refractory period: limited amount of about 200 AP per second and AP is
propagated down the axon in one direction only
AP in myelinated axons jumping from one node of Ranvier to the next (salutatory conduction)
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