Topic 3 Flashcards
(46 cards)
Biological psychology
Studies the relationship between the nervous system and behavior
Researchers are biological psychologists or neuroscientists
Brain mapping methods (Before)
Phrenology
Brain Damage
Phrenology (brain mapping)
Skull shape through to reflect brain size and cognitive function
Discredited by mid-1800s
Brain Damage (brain mapping)
Understanding how the brain works by seeing how it doesn’t
Studies of cognitive function in people with brain damage (part of neuropsychology)
Brain Imaging
Techniques involving radiation:
*CT Scan
*PET scan
Techniques involving magnetic fields:
*MRI
*FMRI
Techniques involving electric activity
* EEG
Computerized tomography (CT) scan
Involves X-rays and creates an image through X-rays passing through varied densities within the brain
A CT scan can be used to show brain tumors
Positron Emission Tomography (PET) scan
Helpful for showing brain activity
Invloces injection of mildly radioactive substances and monitoring changes in blood flow to different brain areas
Magnetic Resonance Imaging (MRI) & FMRI
Magnetic fields are used to produce pictures of tissue
Functional MRI shows changes in metabolic activity over time
Electroencephalography (EEG)
Recording the electrical activity of the brain via electrodes on the scalp
EEG research can study the precise timing of overall brain activity by tracking amplitude and frequency
Challenging to study small areas
Brain mapping continued
Magnetoencephalography (MEG):
*Measures tiny magnetic fields generated by the brain
*Used to identify the location of epilepsy-related seizures
Deep brain stimulation (DBS):
*Modify brain function throught implanted electrodes
*Used as a treatment for disorders (e.g parkinsons, depression)
Transcranial magnetic stimulation (TMS):
Applies strong and quickly changing magnetic fields to the surface of the skull that can either enhance or interrupt brain function
Interpreting brain imaging
They are not photos of the brain in action
How brain activity during an activity of interest increases, decreases or differs relative to a control
Brain area activity on brain scan could mean neurons are inhibiting rather than exci0ting
Scientifically, extremely persuasive (like expert testimony) - problematic when introduced into the courtroom (e.g. to prove diminished culpability)
The nervous system (An overview)
Neurons:
* The building blocks! Consistently created and pruned during life
Action Potentials:
* Never impulse or electrical signals that travel down an axon
Glial Cells:
*Support nourish & protect neurons
Neurons meet at synapses
Neurons communicate through neurotransmission
Neurons
The brain communicators
Neurons are nerve cells, specialized in communicating with each other
building blocks of the nervous system
Transmit information in the form of electrical signals
Neural components
Cell body (soma): center of neuron, builds new cell components
Dendrites: branchlike extensions that receive information
Axons: “tails” that transmit information
Axon terminal: knob at the end of the axon containing synaptic vesicles filled with neurotransmitters
Synapse (synaptic clef): space between neurons through which NTs travel (meeting place)
Glial Cells
Glial means glue
Plentiful in the brain
Play valuable support role, involved in psychological functioning
Bodyguards: Feed & protect\
Myelin Sheath
Fatty insulation from glial cells surrounding the axon
Multiple sclerosis (ms): loss of myelin causes erratic signals
How does a neuron fire
called action potential
Step 1: resting potential
*Neuron is polarized (negative inside, positive outside)
*Selectively permeable - gates don’t allow sodium ions (Na+) to pass through
Step 2: action potential - brief electrical charge that travels down neuron
*Transmits neural messages to other neurons, muscles etc.
*Frequency = intensity
Step 3: Repolarization
*Potassium (Ka+) flows out repolarizing the axon
Step 4: Return to resting potential
Step 5:refractoryu period
*Brief period of time where neuron wont fire no matter how much stimulation
Electrochemical communication
When an electrical signal reaches the end of an axon (electro), it triggers the release of neurotransmitters into the synapse (chemical)
Neurotransmitters then bind to receptors of receiving neuron dendrites, transmitting the signal
Excitatory: Messages that make it more likely a neuron will fire
Inhibitory: Messages that make it less likely that a neuron will fire
Neurotransmitters (Functions)
Chemical messengers that help neurons communicate with each other:
*Influence emotions & mood (serotonin & dopamine)
* Control movement (acetylcholine)
(Implicate mental illness
* Regulate sleep and alertness (GABA & norepinephrine)
* Learning & memory (glutamate)
* Implicate mental illness
Release:
* Action potential trigger neurotransmitter (NT) released from vesicles into the synaptic cleft
* NTs bind receptors on the postsynaptic neuron (lock and key)
Reuptake:
* Excess NTs are removed by drifting away, being broken down.
* reabsorbed Reuptake: NTs are taken back into the presynaptic neuron
* Some drugs block reuptake prolonging NT effects
Agonist:
* Mimic or enhance the effects of an neurotransmitter (helpers)
Antagonist;
* Block or impeds the normal activity of a neurotransmitter (blockers)
Opioids (e.g, fentanyl) vs. Naloxone
Schizophrenia associated with excess dopamine→ dopamine antagonists prescribed
Parkinson’s associated with low dopamine → prescribed dopamine agonist
Neurotransmitters (List)
Glutamate
GABA
Acetylcholine
Dopamine
Serotonin
Anadamines
Glutamate and GABA
Most common NTs in the CNS
Associated with learning and memory.
Associated with learning and memory
Glutamate is excitatory and increases the chace that neurons will communicate:
* Tocix in high doses, may contribute to schizophrenia and other mental disorders
GABA is inhibitory, dampening neural activity
Acetylcholine
Arousal, selective attention, memory, sleep
Anticholinergic: Benadryl, unison:
* Increased risk of dementia
Alzheimer’s → Neurons containing acetylcholine are destroyed, leading to memory loss
Aricepyt -> boosts acetylcholine levels
Insecticide limits breakdown (more acetylcholine)
Dopamine
Pleasure and reward voluntary movement
Attention
Parkinson’s → deficit of dopamine
Schizophrenia + symptoms → excess dopamine
Serotonin
Sleeping, eating, mood, pain, depression
Increase serotonin by eating food rich in tryptophan, working out “Runners high”, and light exposure to depression drugs act on serotonin - increase availability
MDMA causes massive release, empties the tank
