BioCog Psychology Part 1 Flashcards
Neurogenesis
generation of new neurons
Dualism vs Monism
Dualism: mind & body are two separate entities
Monism: both are one single entity
Institutional Animal Care and Use Committee (IACUC)
responsible for the review of experiments involving animals; ethics and safety
Stroke
caused by bleeding or obstruction of a blood vessel
Possible effects:
- partial paralysis
- inability/difficulty to read or write
- inability/difficulty to converse
Institutional Review Board (IRB)
Responsible for reviewing experiments’ methods to ensure ethical and safe use of participants in research; informed consent
Cognitive Psychology
Scientific study of the mind
Donders 1868
Reaction time experiment; uses the subtraction method
simple reaction time vs discrimination reaction time
commonly a go-no go task
simple presence + discrimination task
Wundt 1879
First psychology laboratory
- structuralism
- analytic introspection
- empiricist approach
1885 Ebbinghaus
Memory experiment
- quantitative measurement for memory
- memorising nonsense, how long it took, delay, time needed to relearn
- savings: original time - time to relearn
1913 Watson
founding of behaviourism
focus on observable behaviours; close association with classical conditioning
1948 Tolman
Experiment with rats in a maze
cognitive map
Dichotic listening
Cocktail party phenomenon
Cognitive Neuroscience
study of the physiological basis of cognition
Receptor neuron
neuron specialised in receiving environmental information
Resting potential
Value of electrical signal of a neutron when at rest (-70mv)
Action potential
nerve impulse
electrical signal traveling along the axon
charge increases to +40mv
lasts for 1 millisecond
Neurotransmitter
specific chemical which is released from the terminal buttons into the synapse due to an action potential
sends a signal to the following neuron
Feature detector neurons
neurons which are sensitive to specific features of a stimulus
Specificity coding
an object is represented by a single neuron
vulnerable
“Grandmother cells”
Population coding
object is represented by many neurons
inefficient
Sparse coding
object is represented by a few neurons
more efficient, but also vulnerable
Localisation of function
specific behaviours are controlled by specific areas in the brain
Broca’s area
area in the left frontal lobe
specialised for speech production
Wernicke’s area
area in the temporal lobe
specialised for language comprehension
Prosopagnosia
inability to recognise faces
Electroencephalography (EEG)
registers electrical activity on the scalp, produced by the brain
temporal resolution, no spatial resolution
Magnetoencephalography (MEG)
coils register magnetic activity produced by the brain
temporal resolution, no spatial resolution
Positron Emission Topography (PET)
Uses radioactive substances to trace blood flow and usage in the brain
spatial resolution, no temporal resolution
Functional Magnetic Resonance Imaging (fMRI)
Creates images of the brain, measures changes in specific areas
spatial resolution, no temporal resolution
Single Cell Recordings
Records activity of a few single neurons
highest temporal and spatial resolution
invasive, but non-manipulative
Myasthenia gravis
autoimmune disease
brake down proteins in cells which allow a neuron to receive information
no cure; drug treatments
Central Nervous System (CNS)
Brain + spinal cord
Peripheral Nervous System (PNS)
Consists of all the neurons and cells outside of the brain and spinal cord
Sensory neurons
Collect sensory information from the body and transmit it further
part of the PNS
Motor neurons
contract and release muscles to produce movement
part of the PNS
Interneurons
facilitate communication between sensory and motor neurons
part of the CNS
Parts of a neuron
Cell body (soma): shape varies per type of neuron; contains the nucleus; operates the cell
Dendrites: receive information from other neurons or from the environment
Axon: carries an action potential from one end of the neuron to the other; covered in myelin sheaths
Terminal buttons: release neurotransmitters due to the action potential; clean up left over neurotransmitters
Membrane
Protective outer layer of the cell
Cytoplasm
A jelly-like substance which fills the empty space inside of a cell
Nucleus
Contains the nucleolus - responsible for producing ribosomes; houses the chromosomes of the cell - when active, they produce mRNA which will attach to ribosomes
Mitochondria
produces the energy source ATP (Adenosine Triphosphate)
Endoplasmic reticulum
produces, stores and transports proteins
Golgi apparatus
packs neurotransmitters into vesicles
Lyosomes
break down unneeded matter in the cell, to be recycled
Microtubules
Used to transport vesicles form the cell body to the terminal buttons
Kinesin and Dynein
Pick up and carry vesicles along the microtubules
Kinesin: anterograde transport (soma to terminal buttons)
Dynein: retrograde transport (terminal buttons to soma)
Astrocytes
Exist in the CNS; provide physical support to neurons in the brain; clean up debris in the brain; control chemical environment and compassion around the neurons; provide nourishment (glucose) to neurons; isolate synaptic clefts.
Oligodendrocytes
Create several myelin sheaths in the CNS
Schwann cells
Create a single myelin sheath in the PNS
Microglia
act as phagocytes: break down dead/dying cells by engulfing them; part of the brains immune system
Resting potential
Potential of a neuron when it is at rest; usually around -70mv
Hyperpolarisation
Inside of the cell becomes more negative relative to the outside
Depolarisation
Inside of the cell becomes less negative relative to the outside
Threshold of excitation
Set point of potential; once passed, an action potential will be generated
Action potential
Caused by depolarisation of the cell, depolarises more and causes a charge/message to be sent down the axon to the terminal buttons
Diffusion
Force which causes particles to even out their concentration
Electrostatic pressure
Force which causes oppositely charged ions to attract and ions with the same charge to repel eachother
Sodium-potassium pump
Maintains membrane potential by exchanging 3 outgoing Na+ molecules for 2 incoming K+ molecules
Uses 40% of a cell’s metabolic resources
Ion channels
Channels in the membrane, which are ion-specific and usually voltage-activated
All-or-none law
Action potential has the same magnitude every time, will either activate or not
Saltatory conduction
Conduction of an action potential along a myelinated axon; potential is generated at the nodes of Ranvier, zips across the myelin sheath and is re-generated at the next node; faster and more efficient than unmyelinated conduction
Vesicles
Containers for neurotransmitters, created by the Golgi apparatus, and filled by the endoplasmic reticulum.
Kiss and run
Method of releasing neurotransmitters; vesicle merges lightly with the membrane, empties, and removes itself from the membrane
Merge and recycle
Method of releasing neurotransmitters; vesicle merges completely with the membrane; membrane is then pinched off to create a new vesicle
Bulk endocytosis
Method of releasing neurotransmitters; large part of the membrane is pinched inwards then is pinched off multiple times to create vesicles
Ionotropic receptor
Neurotransmitter attaches to the binding site which activates a certain ion channel to open
Metabotropic receptor
Neurotransmitter attaches to the binding site, activates a nearby G-protein which activates an enzyme and creates a second messenger which opens nearby ion channels
Carbon chains
Long chain of carbon atoms bound to hydrogen atoms (and oxygen) e.g. glucose C6H12O6
Amino acids
Carbon chain with a nitrogen atom and a carboxyl group
Protein
Strand of amino acids
Peptides
Short protein chain
Lipids
Long carbon chains; are hydrophobic
Phospholipids
carbon chains connected to an extra phosphate group; head is hydrophilic, tails are hydrophobic
Inside of the cell
High concentration of K+ (potassium) and A- (organic anions). A- is pushed out by diffusion and electrostatic pressure, but the cell’s membrane is impermeable to A-. K+ is pushed out by diffusion but pushed in by electrostatic pressure.
Outside of he cell
High concentration of Cl- (chloride) and Na+ (sodium). Cl- is pushed in by diffusion and out by electrostatic pressure. Na+ is pushed in by both diffusion and electrostatic pressure; membrane is less permeable to Na+.
Action potential mechanism
- Cell is depolarised enough that Na+ channels open, cell depolarises more
- K+ channels start to open, flow out of the cell
- Na+ channels close, at the peak of the action potential, and lock themselves
- K+ keeps flowing out, potential becomes negative again
- K+ channels close, Na+ channels ‘unlock’ but remain closed
- Due to the outflow of K+, the potential is slightly more negative than at rest, but is restored quickly due to the sodium-potassium pump
Psychopharmacology
Study of the effects of drugs on behaviour and the nervous system behaviour
Drug effects
Observable changes in physiological processes and behaviour (as the result of a drug)
Sites of action
Areas where the molecules from the drug interact with molecules from the body
Pharmacokinetics
Absorption, distribution, metabolism, and excretion
Absorption
Method of administration and intake of a drug
e.g. IV injection, oral administration, inhalation, etc.
Distribution
Way in which the drug reaches its sites of action
lipid solubility: ability of fat-based molecules to pass through cell membranes; blood-brain barrier is only against water soluble molecules
more lipid soluble > faster distribution
Metabolism
Drugs are deactivated by enzymes; most found in the liver, some in the bloodstream and in the brain
some molecules are more effective after transformation by an enzyme > longer-lasting effects
Excretion
Usually by way of the kidneys > filtered out of the bloodstream
Therapeutic index
Indicates the ‘safeness’ of the drug (ratio of beneficial vs toxic effects)
higher index > safer to use
Effects of repeated administration
Tolerance: effects of the drug diminish
Sensitisation: drug effects increase
Withdrawal symptoms: usually the opposite effect of the drug; occur after the body has ‘compensated’ for the drug
Physical dependence: person experiences withdrawal symptoms; body has difficulty working without the presence of the drug
Placebo
An inactive substance
Placebo effects
Placebo may produce an effect if the person believes it has any
Agonist
Drug which facilitates synaptic transmission and/or postsynaptic effects
Antagonist
Drug which inhibits synaptic transmission and/or postsynaptic effects
Direct agonist
A drug which imitates a certain neurotransmitter by binding to postsynaptic receptors
e.g. nicotine
Direct antagonist
A drug which binds to a postsynaptic receptor to prevent a neurotransmitter from activating; also known as receptor blockers
e.g. chlorpromazine
Noncompetitive binding
Binding to alternative receptors not meant for neurotransmitters
Indirect antagonist
A drug which attaches to an alternative site and prevents its ion channel from opening
e.g. PCP & ketamine
Indirect agonist
a drug which attaches to an alternative site and facilitates its ion channel from opening
e.g. diazepam/valium
Amino acids
Glutamate: main excitatory neurotransmitter in the CNS; affects motor control and learning
GABA: main inhibitory neurotransmitter in the CNS; affects motor control
Glycine: inhibitory neurotransmitter found in the spinal cord; affects motor control
Acetylcholine
Affects learning, memory, and dreaming
Monoamines
Catecholamines
- Dopamine: inhibitory & excitatory; affects attention, learning/reinforcement and motor control
- Norepinephrine: alertness, fight-flight, sympathetic nervous system
- Epinephrine: fight-flight, sympathetic nervous system
Indolamines
- Serotonin: mood regulation, pain regulation, eating, sleep, and alertness
Histamine: only found in the posterior hypothalamus; important role in wakefulness
Synapse
Contact point between neurons
Exocytosis
process for releasing neurotransmitters into the synaptic cleft
Neuromodulators
Present throughout the entire brain and sensitise or desensitise entire neural networks
- Peptides
- Nucleosides
Ligand
A chemical that can bind to a receptor
Directions for the brain
Neuraxis: parallel to the spinal cord, bent in humans
Anterior: in front; Posterior: behind
Rostral: towards face; Caudal: towards the tail
Dorsal: towards the back; Ventral: towards the front
Superior: above; Inferior: below
Lateral: towards the sides; Medial: towards the middle
Ipsilateral: on the same side; Contralateral: on opposite side
Transverse plane: perpendicular to the neurosis, gives front and back cross sections
Horizontal plane: gives top and bottom cross sections
Sagittal plane: gives left and right cross sections
Meninges
Protective sheath around the nervous system
1. Dura mater: outer layer; durable
2. Arachnoid membrane: soft and spongy; weblike structure for suspension
3. Pia mater: closely attached to the brain, contains small blood vessels
CNS has all three; PNS has 1 & 3
Forebrain
Forms around the lateral and third ventricles; creates the telencephalon and the diencephalon
Later structures: cerebral cortex, basal ganglia, limbic system, thalamus, and hypothalamus
Midbrain
Forms around the cerebral aqueduct; develops into the mesencephalon
Later structure: tectum tegmentum
Hindbrain
Forms around the fourth ventricle; creates the metencephalon and the myelencephalon
Later structures: cerebellum, pons, and medulla oblongata
Progenitor cells
‘Ancestor’ cells
undergo symmetrical and asymmetrical division
Symmetrical division: 1 p cell > 2 p cells
Asymmetrical division: 1 p cell > 1 p cell + radial glia, Cajal-Retzius cell, or a neuron
Cerebral cortex
Outer part of the brain; grey matter
Contains gyri (bulges), sulci (grooves), and fissures (large sulci)
Thickness: ~3mm
Surface area: ~2,360 cm2
Frontal lobe
Front of the brain
Parietal lobe
On the sides, behind the frontal lobe
Temporal lobe
Bottom of the brain (ventral)
Occipital lobe
Back of the brain
Primary visual (striate) cortex
Receives visual information; found at the back of the occipital lobe
Primary auditory cortex
Receives auditory information; found at the top of the temporal lobes
Primary somatosensory cortex
Receives information from the bodily senses; found at the front of the parietal lobe
Primary motor cortex
Controls movement of the body; found at the back of the frontal lobe
Somatic nervous system
Receives sensory information and controls skeletal muscles (voluntary movement)
Autonomic nervous system
Regulation of smooth muscles, cardiac muscles and glands; ‘self-governing’
- Sympathetic: expenditure of stored energy
- Parasympathetic: storage of energy
Neural network development
- Differentiation of ‘types’ of neurons
- Extensions: cells reach out to each other
- Synapse formation: extensions form synaptic connections
- Apoptosis: unconnected cells die
- Pruning: elimination of unnecessary connections between neurons
Cerebellum
‘Little brain’
Contains more neurons than the left and right brain hemispheres
Purpose: motor control, timing thereof, and balance
Thalamus
Relay station for sensory information
Hypothalamus
Part of the autonomic nervous system; fight, flight, feed, and mating; hormone secretion
Basal ganglia
Motor control and motor learning
- Caudate nucleus
- Globus pallidus
- Putamen
- Amygdala
Ventricles
Allow for the circulation of CSF, weight reduction of the brain, and act as shock absorbers
Perception
Experiences resulting from stimulation of the senses; conscious experience and interpretation of sense information
Inverse projection problem
Ability of the brain to correctly identify and interpret the light falling onto the retina
Viewpoint invariance
Ability to recognise the same object from different viewpoints
Bottom-up processing
Knowledge from environmental stimuli influences perceptual systems
Top-down processing
Knowledge from previous experiences is used to interpret what is going on
Speech segmentation
Process of identifying when and where a word ends
Visual agnosia
Inability to recognise familiar objects, faces, and geometrical shapes
Gestalt laws/principles
- Simplest solution
- Symmetry
- Similarity
- Proximity
- Good continuation
- Closure
- Common fate
- Familiarity
Sensation
Detection of environmental stimuli
Sensory receptors
Specialised neurons which detect physical events
Retina
Inner lining of they eye; for vision, an image must be focused on the back of the eye; contains all the photoreceptors
Has 3 layers:
- Photoreceptive layer
- Bipolar cell layer
- Ganglion cell layer
Accommodation
Lens shape can be adjusted to allow the eye to focus on near or distant objects
Cones
Type of photoreceptor; responsible for daytime vision; provides most of the visual information, source of vision with the highest acuity; sensitive to coloured light as well
Retina contains 6 million cones
Rods
Type of photoreceptor; do not detect colour; poor acuity; more sensitive to light; used in dim lighting > no colour and less focus; highest concentration on the outside of the retina
Retina contains 120 million rods
Fovea
Centre point of the retina; highest acuity/focus point; only contains cones
Optic disk
point where axons leave they and form the optic nerve; creates a blindspot as there are no receptors at this point
Transduction
process by which energy from the environment (light) is converted to a change in membrane potential in a neuron; sensory receptors depolarise in response to darkness and hyperpolarise in response to light
Bipolar cells
ON and OFF cells; ON cells are hyper polarised by glutamate; OFF cells are depolarised
Receptive field
The part of the visual field to which a ganglion cell/neuron is sensitive to (what it ‘sees’); detection of stimulus induces a change in firing frequency
Optic nerve
Bundle of axons formed at the back of the eye at the optic disk
The optic nerves from both eyes cross over at the optic chasm and split into left and right visual fields; information is sent to the contralateral’s dorsal lateral geniculate nucleus (LGN)
Dorsal Lateral Geniculate Nucleus (LGN)
Has 6 layers; parvocellular and magnocellular pathways; consult for visual information from the retina to the visual cortex
ON & OFF cells
ON cells:
- Excited by light falling in the centre of their receptive field and inhibited by light falling in the surrounding field
OFF cells:
- Inhibited by light falling in the centre of their receptive field and excited by light falling in the surrounding field
ON/OFF cells:
- briefly excited when light is turned on or off
Trichromatic colour theory
- 3 types of cones to process 3 colours: blue, green, and red
- cone types are sensitive to different wavelengths of light
Colour vision defects
Protanopia: inability to perceive red light
Deuteranopia: inability to perceive green light
Tritanopia: inability to perceive blue light
Opponent-process colour theory
- The retina has two types of ganglion cells: red-green cells and yellow-blue cells
- Red light excites a red cone > excites a red-green ganglion cell
- Green light excites a green cone > inhibits a red-green ganglion cell
- Blue light excites a blue cone > inhibits a yellow-blue ganglion cell
- Yellow light excites both a red and a green cone; red cone excites a red-green and a yellow-blue ganglion cell; green cone inhibits a red-green ganglion cell and excites a yellow-blue ganglion cell; red-green ganglion cell is canceled out, yellow-blue ganglion cell is excited
Cerebral achromatopsia
Defect in colour vision due to damage in the extra striate cortex
Examples:
- loss of colour vision without loss of acuity
- loss of memory of colour
Visual agnosia
Cause by damage to the extra striate cortex; has a variety of effects:
- difficulty recognising faces (prosopagnosia)
- difficulty recognising objects (object agnosia)
Orientation-sensitive neuron
Found in the striate cortex, fire at a rate according to how close the stimulus is to its receptive field
Akinetopsia
Inability to perceive movement
Characteristics of colour
Hue: colour
Intensity: brightness
Saturation: colour purity
Combination of visual information
LGN cells are sensitive to presence of light
Simple cells combine information from LGN cells and are sensitive to orientation and edges/lines
Complex cells combine information from simple cells and are sensitive to movement and specific patterns
Attention
Ability to focus on specific stimuli or locations
Selective attention
Attending to one stimulus while ignoring other stimuli
Focus on one task; attention as a filter
Distraction
A stimulus interfering with processing of another stimulus
Divided attention
Paying attention to more than one thing at a time
Focus is divided over multiple tasks; one or more tasks are usually automated; success depends on processing capacity of the tasks
Attentional capture
Rapid shift of attention, often due to a sudden stimulus
Broadbent’s filter model of attention
Messages > Sensory memory > Filter >attended message> Detector > Memory
Cocktail Party Effect (Cherry, 1953)
Ability to focus attention on one thing and block out others
Processing capacity
Amount of information someone can handle and process at any given time
Perceptual load
Difficulty of the task; how much processing capacity it requires
Overt and covert attention
Overt attention: moving attention in a way that is visible to observers; moving the eyes
Covert attention: shifting attention without moving the eyes; invisible to observers
Automatic processing
Occurs without attention at no cognitive cost
Inattentional blindness
Not attending to something that is clearly visible
Change blindness
Difficulty to detect changes in a scene
Attentional bias
Elevated attention to emotional stimuli
Stroop task
Names of colours presented written in a different colour
Since reading has become automatic for most people; it is quite difficult to ignore what the word says and only name the colours of the ‘ink’
Skeletal muscles
Attach to bones (mostly at each end); tendons attach the muscles to the bone; perform flexion and extension
Also called striated muscles
Flexion vs Extension
Flexion: moving a limb towards the body
Extension: moving a limb away from the body
Antigravity muscles
Muscles used to stand up
Extrafusal muscle fibres
Activated by alpha motor neurons
Intrafusal muscle fibres
Bundled together to create a muscle spindle; wrapped in afferent sensory endings; detect muscle length; activated by gamma motor neurons
Motor unit
Alpha motor neuron + all extrafusal muscle fibres it activates
Neuromuscular junction
Synapse between terminal button of an efferent neuron and the membrane of a muscle fibre
Direct pathway
Promotes motor activity
Activation of the caudate nucleus & putamen increases inhibition of the internal globus pallidus, this decreases inhibition of the thalamus and increases excitation of the motor cortex
Indirect pathway
Inhibits motor activity
Activation of the caudate nucleus & putamen increases inhibition of the external globus pallidus which decreases inhibition of the subthalamic nucleus; increased excitation of the internal globus pallidus and increases inhibition of thalamus which decreases excitation of the cortex
Parkinson’s disease
Caused by a loss of dopaminergic neurons in the substantia nigra which disrupt the afferent pathways to the caudate and putamen
- rigidity, tremors, difficulty with initiation and termination of movement, and impaired postural reflexes
- can be treated with:
- L-dopa medication > may lead to sensitisation with long-term use
- electrical stimulation to inhibit the direct path
Caused by damage to direct path: loss of ability to promote motor activity
Huntington’s disease
Heritable; caused by a degeneration of GABAergic and acetylcholinergic neurons in the caudate and putamen, which would inhibit the external globus pallidus
-involuntary movements, dystonia (cramped posture), athetosis (wiggling toes), ballismus (wild movements), memory loss, and mood issues
Affects the indirect pathway, loss of ability to inhibit movement
Mirror neuron system
- Found at the rostral part of the parietal lobe
- Involved in initiating movement > copying movement
- Stronger activation when the motion is familiar or one is competent in the specific motion
Reaching vs Grasping
Reaching
- mostly controlled by vision > dorsal stream
- parietal reach region
- medial posterior cortex
- determines target location and supplies information about the target’s location to the motor mechanisms
Grasping
- controlled by the anterior part of the intraparietal sulcus (aIPS)
- allows quick control and change of grip posture
- input from dorsal stream of the visual system
- involved in recognition as well as execution of a grasping movement
Apraxia
Category of movement deficits
- Oral apraxia: impairment in use of muscles for speech
- Apraxia agraphia: writing deficit involved with muscle disruption
- Limb apraxia: impairment of correct movement of limbs
- Constructional apraxia: difficulty with drawing or constructing object
Limb apraxia
Damage to left parietal lobe
- Activation of the wrong body parts
- Activation of the right body parts but in the wrong order
- Execution of wrong movement
Constructional apraxia
Damage to right parietal lobe; stems from an inability to perceive and imagine geometrical relations, trouble with spatial perception tasks
- Visuomotor issues > hard to identify parts of a whole
- Inability to copy figures
- Inability to build an object
Alpha motor neurons
- Enable movement of the extrafusal muscle fibres
Acetylcholine is released onto the muscle fibres > activates calcium ion channels > calcium flows into the fibres, causing contraction
Gamma motor neurons
Adjust sensitivity of muscle spindle to detect muscle length
Mechanism of muscle contraction
Extrafusal muscle fibre consists of actin and myosin filaments which shift in opposite directions
Inflow of calcium, due to acetylcholine from an alpha motor neuron, myosin binds to actin and moves along with it in the opposite direction
Monosynaptic stretch reflex
Intrafusal muscle fibres detect a change in muscle length > sign travels via an afferent sensory neuron to the dorsal root ganglion > directly activates a ventral motor neuron which activates the muscle
Does not involve the brain
Polysynaptic inhibitory reflex
Similar to the monosynaptic stretch reflex; prevents excessive tension on a muscle
Golgi tendon organ travels the same way as the sensory neuron > connects to an inhibitory interneuron > interneuron releases GABA to inhibit the motor neuron
Golgi tendon organ
Sensory afferent neurons which attach to the tendons; provide information about the amount of force on a muscle (tension)
Corticospinal paths
Lateral group: for independent limb movements
- Lateral corticospinal tract:
- arms
- hands
- fingers
- legs
- feet
- toes
- Rubrospinal tract (via red nucleus):
- lower arms
- hands (not fingers)
- lower legs
- feet (not toes)
- Corticobulbar tract:
- neck
- face
- eyes
- tongue
Ventromedial group: for balance (body posture) and walking
- Ventral corticospinal tract
- body posture: trunk and upper legs
Cerebellum
Important for motor coordination
- Ventromedial system: deep nuclei for orientation and body posture
- Lateral system: control of independent movements
Damage: impaired ability to time and coordinate movement, particularly at the end of a movement
Supplementary motor area (SMA)
Found at the top of the frontal lobe, in from of the primary motor cortex
Important for sequential movement (e.g playing an instrument or riding a bike)
Premotor cortex
Found in the frontal lobe, underneath the SMA, in front of the primary motor cortex
Important for general motor planning
Basal ganglia: motor gating
Allow (or disallow) movement
Decides which motor plan should be executed
- Caudate nucleus & putamen: input from the substantia nigra, primary motor cortex, and the somatosensory cortex
- Globus pallidus: output to the primary motor cortex, premotor cortex, and the supplementary motor area via the thalamus
Memory
Process involved in retaining, retrieving, and using information about stimuli, images, events, ideas, and skills after the original information is no longer present
Modal model of memory
Input > Sensory memory > Short-term memory < >Long-term memory
+ rehearsal & output
Chunking
Method to ‘increase’ short-term memory capacity by grouping items together
Model of Working Memory (Baddeley & Hitch, 1974)
Phonological Loop (verbal & auditory information)
↓↑
Central Executive
↓↑
Visuospatial Sketchpad (visual & spatial information)
Visual imagery
Seeing an object or scene in the absence of a visual stimulus
Mental imagery
Ability to recreate the sensory world in the absence of any physical stimuli
Reality monitoring
Distinguishing between real and imagined events
Long-term memory
- Unlimited capacity
- No or hardly any decay
- Retrieval may fail due to inadequate retrieval cues
Short-term memory
- Very limited capacity
- Quick decay (within ~ 30 seconds)
- Rehearsed information > long-term memory
Sensory memory
- Unlimited capacity
- Very rapid decay
- Attended information > short-term memory
Primacy effect
Items at the beginning of a list are well-remembered due to rehearsal > long-term memory
Recency effect
Items at the end of a list are well-remembered due to them remaining in short-term memory
Proactive interference
Old information interferes with new information
Retroactive interference
New information interferes with old information
Sleep disorders: Insomnia
Primary: inability to fall asleep before going to bed or after waking up at night
Secondary: inability to sleep due to a mental or physical condition
Sleep apnea: inability to sleep and breathe properly at the same time
Sleep disorders: Narcolepsy
Neurological disorder; sleep symptoms occur at inappropriate times
Sleep attack: overwhelming sleepiness, sleeps lasts for 2-5 minutes, usually due to boredom
Cataplexy: episode of atonia (muscle paralysis typical for REM sleep); person is fully conscious; caused by strong emotions or exercise
Sleep paralysis: REM muscle paralysis occurs just before or after sleep; may include hypnagogic hallucinations
Patients have a severe low amount of orexinergic neurons > malfunctioning flip-flop
Sleep disorders: REM sleep behaviour disorder
Neurodegenerative disorder
Muscle paralysis (atonia) does not occur during REM sleep, causing patients to act out their dreams
May be caused by brain damage to the brain stem which controls REM phenomena
Sleep disorders: Slow-wave sleep problems
Nocturnal enuresis: bedwetting
Somnambulism: sleep walking
Pavor nocturnos: night terrors
Sleep-related eating disorder: eating while sleeping and having no recollection of the fact
Flip-Flop system
vlPOA inhibits the arousal systems, and vice versa
Accumulation of adenosine activates the vlPOA
Orexinergic neurons activate the arousal systems
Long-term memory
System responsible for storing information for long periods of time
Coding
Form in which stimuli are presented
- visual
- auditory
- semantic
Episodic memory
Memory of personal experiences
Semantic memory
Memory of facts and knowledge
Personal semantic memories
Facts associated with personal experiences
Explicit memories
Memories we are aware of; also known as declarative memory
Implicit memories
Memories we are not aware of; can not ‘declare’
Procedural memory
Skill memory, memory for doing things that involve skills (e.g. riding a bike)
Once learned, the procedure will never be forgotten (even after certain brain damage)
Priming
Presentation of a stimulus changes the response to another stimulus
Classical conditioning
Two stimuli are paired; a neutral stimulus, and a conditioning stimulus
Encoding
Process of acquiring information and transferring it to LTM
Retrieval
Process of transferring memory from LTM to working memory
Levels of processing theory
Memory depends on the depth of processing (shallow vs deep processing)
Retrieval cue
Word or stimulus which aids in memory retrieval
Encoding specificity
Memory/knowledge is encoded along with context; memory retrieval is better when context is similar/recreated
Reconsolidation
Mechanism which can be used to update memories
Anterograde amnesia
Inability to create new memories (no consolidation in LTM); loss of relational learning ability
Retrograde amnesia
Loss of past memory due to brain damage; loss of retrieval ability
Semanticisation of episodic knowledge
Nearly all episodic memories contain semantic components
Stimulus-response learning
Learning to perform a behaviour in the presence of a stimulus
- Classical conditioning
- Operant conditioning
Perceptual learning
Better and faster identification of faces/objects if seen before
Motor learning
Learning how to better perform a certain movement/task (e.g. riding a bike or learning a sport)
Relational learning
Learning about the relationships between stimuli
Hebb rule
If the synapse is active at around the same time that the post-synaptic neuron is active, the synapse will be strengthened
Long-term potentiation (LTP)
Synaptic strengthening
Requirements
- Axon must be active (glutamate secretion in synapse)
- Postsynaptic neuron is depolarised
If the requirements are met NMDA receptors can open
- NMDA receptor opens
- Ca2+ ions activate CaM-KII
- Linking proteins attach to CaM-KII
- AMPA receptors are delivered to membrane in vesicles
- Additional AMPA receptors are inserted into the membrane
Reinforcement
Promotes behaviour
- Positive reinforcement: behaviour leads to a reward
- Negative reinforcement: behaviour leads to the removal of a negative stimulus
Punishment
Reduces behaviour
- Positive punishment: behaviour leads to a negative stimulus
- Negative punishment: behaviour leads to the removal of a positive stimulus
Autobiographical memory
Memory for specific experiences from our life; combines episodic and semantic memory
Reminiscence bump
Enhanced memory for events that occurred in adolescence and early adulthood
- self-image hypothesis
- cognitive hypothesis
- cultural life script hypothesis
Categorisation
Definition: list of necessary and sufficient properties
Prototype: central (avg.) representation of a category
Graded representation: membership of a category depends on similarity/distance to the prototype
Schemata
General knowledge about situations
Scripts
General knowledge about a sequence of events
