Chapter 3.1 Flashcards
Biological psychologist / neuroscientist study
brain and behaviour
how many neurons does the brain contain
approx 100 billion
What is phrenology
exploration of the shape, size and protrusions of the cranium
beleifs of phrenology
(3 things)
- our brain is the sole organ of the mind
- characteristic trains and intelligence are inherited
- diffrences between people = a diffrence in brain structure
How was phrenology disproven
- damage to areas that should correspond to traits/function did not lead to those deficits
Electrical stimulation studies investigated brain function by
stimulating the brain during neurosurgery
what do electrical stimulation studies support
- the idea that neural communication is electrical in nature
Which neurosurgeon was intergral to the development and expansion of electrical stimulation
Wilder Penfield
Lesion or damage studies purpose
- study psychological functioning through assessing people with brain damage to a specific area and nothing deficits
- ANIMALS: created damage to a certain area to understand specific impairment
Electroencephalography (EEG)
- the recording of the branins electricle activity at the surface of the skull
EEG advantage
- non invasive
- very high temporal resolution
EEG Disadvantage
- doesnt tell us about the individual cell activity
- doesn’t tell us about brain region activation with great accuracy
Computed tomography (CT)
- uses multiple x rays to build a 3D reconstruction of the brain
CT advantages
- good for detecting dense tissue
CT disadvantages
- produces static image
- no detail regarding activity over time
Position Emission Tomography (PET)
- uses trace amounts of short lived radioactive material to map functional processes of the brain
PET advantages
- can attach radioactive isotopes to drugs to see where they are used
PET disadvantages
- invasive
- poor time course )static images)
- poor spatial resolution
Structural MRI
- uses magnetic feild to indirectly visulaize brain structure
Advantages of MRI
- higher spatial resolution image than CT
- superior to CT for detecting soft tissues
Disadvantages of MRI
- expensive
- produces a static image
- no detail regarding activity, or activity over time
Functional MAgnetic Resonance Imaging (fMRI)
- detects the changes in blood oxygenation and flow that occur in responce to neural activity
- is standard technique used in brain imaging research
What is standard technique used in brain imaging research
fMRI
Advantages of fMRI
- can see activity with good image and clarity over time
fMRI disadvantages
- poor temporal resolution (better than PET/CT)
- expensive
Magnetoencephalography (MEG)
- measures brain activity by detecting tiny magnetic field generated by the brain
Advantages of MEG
- exellent temporal resolution
- resonably spatial resolution
MEG disadvantages
- not great at detecting activity deeper in the brain
- expensive
- requires high degree of technical expertise
Deep Brain Stimulation (DBS)
- is where battery powered electrodes are implanted within the brain to provide electrical stimulation direction to certain areas
Advantages of DBS
- can be used to treat neuropsychological conditions and asses brain activity
Disadvantages of DBS
- very invasive
- researchers to not have control of where the electrodes go. Must be planted for medical purposes
Risks of DBS
- requires brain surgery
- infection
- haemorrhage
- battery replacement requires more surgery
Transcranial Magnetic Stimulation (TMS)
- applies strong and quickly changing magnetic field to the surface of the skull that can either enhance or interrupt brain function
Advantages of TMS
- active inhabitation of neural function for movements
Disadvantages of TMS
- can cause seizures if used incorrectly
- can only operate on outer layer of the brain (cortex)
Localization of Function
- when areas of the brain are found to be particularly active during specific psychological task
Example of localization of fucntion
- brocas area
How much of our brains do we use
100%
Components of a neuron
- cell body (soma)
- dendrites
- axon
- axon terminal
neural communication within a cell is communicated
electrically
neural communication between cells is communicated
chemically
Chemical information is transfer through the
synapse
Glial cells
- supports neurons and neuron functioning
Astrocytes
- responsible for the BBB
Oligodendrocytes
- responsible for the myelin sheaths of some axons
Neural communication: all or none law
- must reach threshold to produce an action potential
- doesn’t reach potential = no depolarization
- stronger than threshold = MORE action potential
Absolute refeactory period
- 1-2ms after initiation of an action potential; impossible to another action potential to occur
Relative refactor period
- 2-4ms after an action potential; more stimulation is needed to trigger another action potential
Neurotransmitters
- chemical substances that carry messages across the synapse to either excite other neurons, or inhibit their firing
five stages of chemical communication
- synthesis
- storgage (synaptic vessicle)
- release (synaptic space)
- binding (receptor sites)
- deactivation (reuptake or breakdown)
types of neurotransmitters
- excitatory
- inhibitory
Excitatory postsynaptic potential (EPSP)
- postsynaptic depolarization
- post synaptic neuron more likely to fire
Inhibitory postsynaptic potential (IPSPs)
- postsynaptic hyper polarization
- post synaptic neurons less likely to fire
Glutamate role
- main excitatory neurotransmitter
- sensory and learning
Glutamate drugs
- alcohol and sensory enhancers
GABA role
- main inhibitory neurotransmitter
GABA drugs
- alcohol and anti-anxiety
Norepinephrine role
- cortical arousal
NE drugs
- amphetamine and methamphetamine
Acetylcholine role
- cortical arousal, selective attention, memory, muscle contradiction
ACh drugs
- nicotine
- memory enhancers
- botox
Dopamine role
- motor function
- reward
-pleasure
Dopamine drugs
- L dopa (parkisons disease)
- Antipsychotics
Serotonin role
- mood regulation
- aggression
- wake-sleep cycle
- temperature
Seratonin drugs
- SSRI anti-depressants
Endorphins role
- pain killers
Endorphin drugs
- codeine
- morphine
- heroin
Anandamide role
- pain killers
- increase in appetite
Anandamide drugs
- TCH (marijuana)
Psychoactive drugs impact the
brain
Agonistic psychoactive drugs effect
- enhances activity at the receptor site
- binds to receptor site of blocks reuptake
Antagonist psychoactive drugs effect
- reduces active at the receptor site
- binds to receptor site and blocks neurotransmitter (competitive inhibitor)
Neural plasticity
- the ability of neurons to change over time
- could change in terms of structure of function
3 areas related to neural plasticity
- plasticity over development
- plasticity and learning
- plasticity following injury / degeneration
Networks of neurons in the brain change the course of development in four primary ways
. What are theses?
- growth
- synptogenesis
- pruning
- myelination
How do brains change as we grow
(3 things )
- synaptogenesis
- potentiation
- structural plasticity
what is synaptogenesis
- creation of new synapses
Our braisn can sometime repair via
neurogenesis
Stem cells
- cells that have not yet differentiated
- have the capability of becoming almost any type of cell in the body
