PSYD13 Delkurs 1 - The Brain Flashcards
Who is Phineas Gage and why is the important in psychology?
Gage had a leisure in his frontal lobe which resulted in a change in personality/moral, which gave us gained knowledge in the functions of the frontal lobe
Which 2 parts can the nervous system be divided into?
The CNS and PNS
What does the CNS consist of?
The brain and the spinal cord
Which 2 (four) parts can the PNS be divided into?
The somatic system and the autonomic system (which can be divided into the sympathetic and parasympathetic nervous systems)
What is the PNS?
= contains all the neural structures that lie outside the brain and spinal cord
What is the somatic nervous system and what is its function?
The somatic nervous system contains of pairs of spinal and cranial nerves that are controlled by the CNS. It’s main function is voluntary muscle activation.
Spinal nerves
controlled and monitored by the spinal cord, receive information from the skin
Cranial nerves
controlled and monitored by the brain, both sensory and motor functions (both receives and sends information). Is a set of 12 paired nerves that control ex eye movement, tongue muscles, vision and so on
What is the autonomic nervous system (ANS) and what is its main function?
The ANS is divided into the sympathetic and parasympathetic systems. Its main function is the opposite of the somatic nervous system - it controls involuntary movement.
What is the sympathetic nervous system and what is its function?
It is also known as our fight or flight response. The CNS signals the sympathetic nervous system when we for example are in a stressful situation, and the sympathetic nervous system sends signals to for example our heart.
What is the parasympathetic nervous system and what is its function?
Known as the rest and digest response, the opposite to the sympathetic nervous system.
What bodily function does the sympathetic and parasympathetic nervous systems collaborate to attain?
Homeostasis!
What is homeostasis?
“a delicately balanced or constant internal state”,
What are neurons?
The functional building blocks of the nervous system; cells that transmit the electrical activity that underlies psychological processes
What are glial cells?
Glial = glue in greek. Glial cells serve to support neurons, by for example holding them in place and protecting them from toxins. Think for example myelin sheets! (oligodendrocytes in CNS and Schwann cells in PNS).
What are sensory and motor neurons?
Sensory neurons recieves and carries input from the sense organs to the spinal cord and the brain, whereas motor neurons carry output from the brain and the spinal cord to our body’s muscles and organs.
What are interneurons?
they perform connective or associative functions within the nervous system, for example, interneurons link sensory input from the visual system to our hippocampus, so that you can recognise a friend.
Soma?
Cell body
Dendrites?
receive information from the pre-synaptic neuron
Axon?
conducts electrical impulses away from the cell body to the post-synaptic neuron/muscles and glands
Axon terminals?
at the end of the axon one finds the axon terminals, where the electrical impulse is transmitted to the post-synaptic neuron with the help of neurotransmitters
Synapse (synaptic cleft)
the gap between the pre-synaptic neuron (the axon terminals) and the post-synaptic neuron (their dendrites).
Myelin sheath?
fatty layers made out of glial cells that surrounds the axon.
Nodes of ranvier
the gaps on the axon between the myelin sheath. The neural impulse “jumps” in the gaps which creates a quicker neural impulse.
What is the resting potential of a neuron?
The resting potential of a neuron is -70mV (compared to the intercellular space of 0 mV). One can think of the function of the resting potential as a charged arrow.
What is an action potential?
An action potential is the electrical shift across the cell membrane
How does an AP occur?
When the neuron recieves an electrical impulse and the axon hillock reaches the threshold (-50mV) -> voltage sensitive ion channels open and sodium (Na+) flows into the intercellular space -> 35mV = depolarisation
What happens after the AP (after the axon hillock has reached 35mV and sent an electrical impulse down the axon)?
After the AP during recovery (to the resting potential) potassium ions leave the intercellular (in attempt to recover the resting potential) which results in an absolute refractory period. During this period the neurons cannot receive any signals. Then,
What is a function of the absolute refractory period?
It ensures that the electrical impulse does not travel back down the axon, i.e. forces it to travel to the post-synaptic neuron.
What are graded potentials?
= local ionic concentration changes across the cell membrane, i.e. when changes in the resting potential do not reach the -50mV threshold. However, several graded potential can “together” trigger an AP in a post-synaptic neuron.
What is the all-or-none law?
the size and shape of the AP remains constant along the axon - this is because an AP triggers another AP along the axon, which creates a domino-effect.
Ion channels?
“Gates” that lets in or keeps out ions. They are what make the cell membrane selectively permeable, i.e. selectively keeps out or lets in ions.
Synaptic vesicles?
Chambers within the axon terminals that store neurotransmitters
Neurotransmitters?
Chemicals released by nerve cells that allows them to communicate with one another
Receptor sites?
Large protein molecules embedded in the receiving neuron’s cell membrane, i.e. the receptor molecules that binds neurotransmitters from the pre-synaptic neuron.
What does it mean that neurotransmitters can be either inhibitory or excitatory?
Excitatory: causes the post-synaptic neuron’s sodium channels to open -> influx of sodium -> AP
Inhibitory: either causes efflux of potassium (K+) or influx of chloride (Cl-) -> can inhibit the post-synaptic to reaching the AP threshold even if it recieves signals from other neurons.
What are the 5 steps of neurotransmission?
- Synthesis 2. Packaging and storage 3. Release 4. Receptor action 5. Inactivation
What is the function of Acetylcholine (ACh)?
Excitatory at synapses involved in muscular movement and memory
Disorders associated with Acetylcholine?
Alzheimers (undersupply) paralysis (absence) violent muscle contractions (oversupply)
What is the function of Noradrenaline?
Excitatory and inhibitory functions at various sites involved in neural circuits controlling learning, memory, wakefulness and eating
Disorders associated with Noradrenaline?
Depression (undersupply) stress and panic disorders (overactivity)
What is the function of Serotonin?
Inhibitory or excitatory: involved in mood, sleep, eating and arousal, and may be important transmitter underlying pleasure and pain
Disorders associated with Serotonin?
Depression; sleeping and eating disorders (undersupply) OCD (overactivity)
What is the function of Dopamine?
Excitatory; involved in voluntary movement, emotional arousal, learning, memory, and experiencing pleasure or pain
Disorders associated with depression?
Parkinson’s disease and depression (undersupply); schizophrenia (overactivity)
What is the function of GABA?
Inhibitory transmitter in motor system
Disorders associated with GABA?
Huntington’s disease + personality change
What is the function of endorphin?
Produced by the hypothalamus and pituitary gland, which inhibits transmission of pain impulses (=neuromodulator)
Disorders associated with endorphin?
Insensitivity to pain (oversupply); pain hypersensitivity + immune problem (undersupply)
What is the function of Glutamate?
Excitatory, a mediator of excitatory info in the NS; involved therefore in most aspect of brain function
Disorders associated with Glutamate?
Neurotoxin, a contributor to a number of neurodegenerative disorders such as Alzheimers (oversupply); seizures, tremors and insomnia (undersupply)
What are psychoactive drugs?
Chemicals that produce alterations in consciousness, emotion and behaviour
What are agonist psychoactive drugs?
A drug that increases the activity of a neurotransmitter
What are antagonist psychoactive drugs?
A drug that inhibits or decreases the action of a neurotransmitter
What is neuropsychology
The study of the function of the brain by investigating the effects of brain damage on mental functions
What are 6 different causes of brain injury?
Vascular, tumour, degenerative disease, infectious disease, trauma and epilepsy
What is a single dissociation?
A demonstration that a lesion to brain region A disrupts function X but not function Y
What is a double dissociation?
A demonstration that a lesion to brain region A imparts function X but not function Y and that a lesion to brain region B imparts function Y but not X.
Compared to a single dissociation, what does a double dissociation prove better?
Double dissociation provide stronger evidence that function X and function Y are supported by independent mechanism.
Wernicke’s aphasia?
= problem w speech comprehension
Broca’s aphasia?
= problem w speech production
What is EEG? (brain imaging)
Measures the activity of large groups of neurons through a series of large electrodes placed on the scalp
What is MEG? (brain imaging)
A brain imaging method that detects activity via the magnetic fields generated by brain activity
What is MRI? (brain imaging)
Creates images based on how atoms in living tissue respond to magnetic pulse delivered by the device
What is DTI? (brain imaging)
Measures how water molecules diffuse in tissue
What is fMRI? (brain imaging)
Can produce pictures of blood flow in the brain taken less than a second apart
What are PET scans? (brain imaging)
Measures brain activity, including metabolism, blood flow and neurotransmitter activity
What is fNIRS? (brain imaging)
Can show which parts of the brain are using the most oxygen
What is TMS? (brain stimulation)
Electrical stimulation of a targeted part of the brain via magnetic pulses sent from an electromagnetic coil
What is TES? (brain stimulation)
Electrical stimulation of the brain by applying a low current to the scalp
How can you anatomically divide the brain?
Forebrain, midbrain and hindbrain
How do you define the hindbrain and what parts does it have?
= the lowest and most primitive part of the brain and contains the medulla, pons and the cerebellum
Medulla?
Composed largely of tracts (bundles of axons)
Controls vital body movements (muscle tone vital reflexes, breathing and cardiovascular system (blood circulation)
Origin of the Reticular formation (=part of the reticular activating system (RAS), which is the system that controls sleep-wake behaviour and arousal
Damage = life threatening
Reticular formation? (RAS)
The system that controls sleep-wake behaviour and arousal
Pons?
a continuation of the medulla. Function is to connect the Cerebellum with the rest of the brain
Cerebellum?
Main function: coordination (i.e. motor plan, position sense, feedback) and motor learning (ex. Deadlifts!)
Also involved in higher cognitive functions such as language, planning, reasoning etc.
Damage -> ataxia = lack of coordination w voluntary movements + drunk !)
How do you define the midbrain and what parts does it have?
The midbrain contains clusters of sensory and motor neurons and contains of the Tectum dorsal surface (Colliculi) + Tegmentum medial and ventral surface (Periaqueductal gray and Substantia Nigra + Red Nucleus)
Colliculi?
The inferior (auditory) and superior (visual)
Receives auditory and visual information
Periaqueductal gray?
it’s function is connected to pain
Substantia Nigra + Red Nucleus?
Motor initiation and movement control.
How do you define the forebrain and what parts does it contain?
It is the brain’s most recently evolved portion and contains the thalamus, hypothalamus, cerebral cortex / + limbic system
Thalamus?
= the brain’s post office/”sensory switchboard”. It recieves all (except smell) sensory information before sending it on to the corresponding areas in the cerebral cortex. Also seems to have a connection with schizophrenia and hallucinations (?)
Hypothalamus?
Is an area that contains lots of nuclei (cell bodies).
- Controls functions for maintaining homeostais (ex. body temperature, thirst and hunger)
- Controls hormone release (ex. fight-or-flight via the pituitary gland
- Vital role in regulation of emotions, sexuality, etc.
Limbic system?
Contains more parts than are brought up in the book, but it is mainly the amygdala and the hippocampus
Amygdala?
The so called “fear-centre”. The amygdala processes emotions but mainly fear, hence the nickname. Damage to the amygdala -> “the fearless woman”
Hippocampus?
Important for both encoding and retrieving memories + learning !! Damage in the hippocampus can result in memory impairment (either problem w encoding or retrieving memories)
How does the amygdala and hippocampus collaborate?
This is easiest to explain with an example: blue square + electric shock - need hippocampus to remember that one associates the blue square with pain, i.e. the collaboration between the amygdala and hippocampus is to do with emotional memories.
What is the cerebral cortex and what 4 lobes make it up?
Is the outermost part of the brain that mostly contains of grey matter - Occipital, parietal, temporal and frontal lobe
Occipital lobe?
Posterior end of the cortex that only processes visual information (however not only part of the cortex that processes visual information - remember: we are visual beings, therefore visual processing takes up a big part of the cortex.
What can leisures in the occipital lobe result in?
Cortical blindness or difficulties recognising objects. It either results in apperceptive or associative agnosia.
Parietal lobe?
- Contains the postcentral gyrus (=”primary somatosensory cortex”, i.e. touch, info from muscle-stretch receptors, joint receptors)
- Visual for action, distance, reading
- Sensory-tactile processing (=processing of touch)
- Spatial attention
- Binding (when seperated signals are binded togehter -> unified perception
Temporal lobe?
- Is the lateral portion of each hemisphere
- Internal structures important for memory and emotional processing (contains amygdala and hippocampus)
- Inferior parts: vision (FFA + PPA) and primary for hearing
- Wernicke’s area
What is the Fusiform gyrus (FFA) and the Parahippocampal place area (PPA) in the temporal lobe?
Face (FFA) and place/scene (PPA) processing areas.
What can leisures in the temporal lobe result in?
The temporal lobe processes a lot of information, so damage can result in a row of different impairments (excluding amygdala hippocampus leisures):
- Wernicke’s aphasia (comprehension)
- Visual agnosias, prospagnosia (face blindness)
Frontal lobe?
Overall function: orienting our behaviours for our goals
- The last part of the brain to develop
- Primary motor cortex
- Premotor cortex
- PFC
- Broca’s area in L hemisphere (language production)
- Metacognition (thoughts about thoughts)
- Inhibition of action
Damage to frontal lobe results in what impariments?
- Broca’s area
- Motor-related impairments (apraxia)
- Change in personality (Phineas Gage)
ETC!!!
PFC function?
Planning, attention, inhibiting, selecting, switching, problem solving, social behaviour and personality.
What is the association cortex?
Is involved in many important mental functions, such as perception, language and thought
Corpus callosum?
A neural bridge consisting of white matter tracts that acts as a major communication link between the 2 hemispheres and allows them to function together
Lateralisation?
Refers to the relatively greater localisation of a function in on hemisphere or the other
What is a split-brain patient?
A patient with a cut corpus callosum
What do split-patient studies reveal about lateralisation?
That genereally, that the left hemisphere comands language and mathematical abilities, whereas the right hemisphere has well-developed spatial abilities, but limited with langauge. Positive emotions in L hemisphere and negative emotions in R hemisphere. However, do not forget that this is general.
What is neural plasticity?
The ability of neurons and brain areas and networks to change in structure and function. Neural plasticity is vital for functions like for example learning (which is done by change of synapses, for example).
What is neurogenesis?
The production of new neurons in the nervous system
What is cognitive neurogenomics?
The study of how the genome of an organism influences the development of the cognitive functions of its nervous system.
What are neural stem cells?
Immature “uncommited” cell that can mature into any type of neuron or glial cell needed by the brain (1st part of neural development).
What is the endocrine system?
- This system consists of numerous hormone-secreting glands distributed throughout the body
- Contains the hypothalamus, pituitary gland, thyroid, adrenal cortex, pancreas, adrenal medulla, ovaries/testes.
Define hormones
Chemical messengers that are secreted from its glands into the bloodstream
What are adrenal glands?
Twin structures perched on top of the kidneys that serve as ‘hormone factories’, producing and secreting about 50 different hormones
Why is the endocrine system interesting to psychologists?
Because of the adrenal glands connection to the nervous system (differences in psychological functions between the sexes).
What are antigens?
Foreign substances that trigger a biochemical response from the immune system