Midterm 1 Flashcards
what is neuropsychology
the relationship between brain function and behaviour
how do we study neuro
study patients with brain lesions, injuries and neurological disorders using cognitive tests and brain imaging
why do you study neuro
to identify brain associations with specific domains. To understand aging, disease, drugs and disorders
what was the earliest evidence of neuro
trepanning: puncturing holes in the skull to relieve pressure, to treat headaches or mental disorders (said to release evil demons
1600BCE
1000CE
1796
1865-1874
1906
discuss battlefield injuries
Middle-Eastern physician’s brain-related surgeries
phrenology (bumps infer personality)
correlating neuroanatomy and neuropathology
study first Alzheimers patient
1913
1966
1970’s
1980’s
1987-1998
word neuropsychology was first used
developments of cognitive and sensory tests
first training programs developed
development of neuroimaging tools
formal training guidelines
Who was H.M and what did he tell us
a patient who had surgery in his medial temporal lobe. he then got anterograde amnesia. He demonstrated that the medial temporal lobe was involved with memory.
What is spilt brain surgery and what does it tell us
cutting the corpus callosum to help stop epileptic seizures. They found that when something was presented in the right visual field, they could correctly identify the object, but not when it was presented in the left. Demonstrated that the left hemisphere is involved with speech and that the hemispheres communicate.
what is blindsight and what does it tell us
blindsight is being unconscious of certain areas in your visual field. but when asked questions about objects, they know more than what you could by chance. This demonstrated that information is still processed by other areas of the brain (brain plasticity). Helped map visual pathways and provided valuable information on the association of vision and consciousness.
what are the lesion studies and what did they tell us
G.H. had damage to his right posterior and had surgery to remove it. he had difficulties with copying drawings, assembling puzzles, and finding his way around a familiar place. M.M. had injury to his left posterior and had surgery to remove it. he had difficulties with solving arithmetic problems, reading, object and animal naming and copying movements. this showed the specialized function of the cerebral hemispheres.
Right = drawing, puzzles, spatial skills and navigation
Left = language, functions, reading, naming, arithmetic
what do modern neuropsychologists do
- expert diagnosticians
- characterize cognitive strengths and weaknesses
- link 1 and 2
- select appropriate interventions
- estimate patient outcomes
- set goals
- direct to proper services
What is the CNS
the brain
- protected by the skull
the spine
- protected by the vertebrae
- carries messages
what is the PNS
contains fibres that carry info to and away from the CNS
SNS
- sensory pathways carry info to the CNS
- motor pathways carry info out of the CNS
- cranial nerves (carry info in and out of the brain)
- spinal nerves (carry sensory info in and out)
ANS
- sympathetic (fight or flight)
- parasympathetic (rest and digest)
frontal lobe
executive functioning
motor cortex
movement
somatosensory
sensory information
parietal lobe
goal-oriented movement
temporal
hearing, language and music
occipital lobe
vision
clefts
sulcus: does not reach the ventricles
fissure: does reach the ventricles
central sulcus
separates the frontal and parietal lobes
lateral fissure
separates the temporal and frontal lobes
longitudinal fissure
separates the hemispheres
corpus callosum
connects the hemispheres
ridges
bumps on the brain (gyri)
The forebrain
mental activities, movement, emotions and behaviours
contains: the cerebral hemispheres, basal ganglia limbic system and diencephalon (hypothalamus and thalamus)
basal ganglia
motor movements, executive functions, behaviour and emotions
limbic system
hippocampus and amygdala
- memory, emotions and behaviour
hypothalamus
- controls the body’s hormone production
- temperature regulations, feeding, sexual behaviour, sleeping, emotional behaviour and movement
thalamus
- channels sensory information travelling to the cerebral cortex from all sensory systems
- relay information, distribution centre to proper areas
The midbrain
the central part of the brain
contains neural circuits for:
- hearing
- seeing
- orientating movements
- pain perception
The hind brain
cerebellum, reticular formation, pons and medulla
cerebellum
motor coordination, motor learning and maintaining body equilibrium
reticular formation
involved with sleep-wake behaviour and behavioural arousal
pons and medulla
controls vital body movements (breathing and swallowing)
The brainstem
- bottom of the brain, which connects the brain to the spinal cord
- regulates body functions and controls balance
contains: midbrain, pons and medulla
what are the 4 types of connections
- projections between lobes
- projections within a lobe
- interhemispheric connections
- connections through the thalamus
gray matter
- 40% of the brain
- contains dendrites, axon terminals and cell bodies (not myelinated)
- involved with cognitive processing
- lose it as we age
white matter
- 60% of the brain
- contains axons (myelinated)
- involved with signal transmission
ventricles
open cavities in the brain (4 all connected)
- ventricles and subarachnoid space are both filled with cerebral spinal fluid
- the bigger the, the smaller the brain (used as a sign of neurodegeneration)
cerebral spinal fluid
deliver nutrients, filter out impurities and cushion the brain
cerebral asymmetry
similar in structure, different in functions
cerebral lateralization
perform a function not shared by the other hemisphere
left side
- language processing, arithmetic, analytic thinking
right side
- visual-spatial processing, emotional processing, holistic thinking
schizophrenia
may have reduced brain asymmetry
dyslexia
may have bilateral language dominance
handedness
some lefty’s show bilateral languages dominance
sex differences
females show much stronger left-sided language lateralization
what are the 3 main functions of the spinal cord
- act as a pathway for impulses going to and from the brain
- control reflexes
- control body movement and functions
cranial nerves
12 pairs
- control sensations and motor movement (head and neck)
spinal nerves
31 pairs
- facilitate voluntary motor control, sensory perception and reflex responses
spinal nerve connections (4)
- posterior root: brings in sensory info (afferent fibres)
- anterior root: send out motor info (efferent fibres)
- carries info to and from the brain
- branches: sensory neurons may influence motor neurons (spinal reflex)
action potentials
convey information from one area to another
- travels down the axon
- synapses carry either excitatory (continue or inhibitory (stop) information
small-molecule transmitters
derived from food and breaks down into acetylcholine (ACh), amines and amino acids
neuropeptide
made through translations of mRNA from instructions in the neuron’s DNA
transmitter gases
Synthesized in the cell as needed
Acetylecholine
essential for communication between motor neurons and muscle fibres, key for rest and digest, involved with learning and memory, arousal and attention
dopamine
plays a role in movement, attention and learning, and in behaviours that are reinforcing
serotonin
involved with mood regulation, aggression, appetite, arousal, pain perception, respiration
norepinephrine
involved in alertness, arousal, attention and the stress response
epinephrine
also involved with stress
glutamate
learning, memory, motor function, pain perception, neuropsychiatric disorders
gamma-aminbutyric (GABA)
stress, anxiety, moody, sleep and pain perception
histamine
controls arousal and walking, constriction of smooth muscles
peptide neurotransmitters
- opioids
- neurohypophyseals
- seretins
- insulins
- gastrins
- somatostatins
corticosteroids
functions:
- hormones
- stress
- mother-infant bond
- learning
- eating regulation
- drinking
- pleasure and pain
cholinergic system (ACh)
- waking behaviour
- attention and memory
dopaminergic system (dopamine)
- coordinating movement
- addiction
- mood regulation
noradrenergic system (NE)
- emotions
- Hyperactivity and ADHD
- learning
serotonergic system (5-HT)
- wakefulness
- learning
- depression and schizophrenia
conventional radiography
x-rays pass through the skull and a shadowy image shows the location of different tissues
- good for skull fractures and gross abnormalities
- not detailed
pneumoencephalography
takes advantage of the fact that X-rays are not absorbed by air
- removes a small amount of CSF from the spinal cord and replaces it with air
- mainly to look at ventricles
- dangerous
angiography
imaging blood vessels
- a substance that is absorbed by x-rays is injected into the bloodstream
- reveals constrictions and abnormalities
- can be painful and dangerous
computed tomography
a narrow X-ray beam goes through the same object at many angles
- localize brain tumours and lesions as they come up darker
- the skull is white, gray and white matter are the same and ventricles are darker
magnetic resonance imaging
a large magnet and radiofrequency pulse generate a signal through the brain that produces an image
- hydrogen atoms nucleus consists of one proton that aligns in the magnet. when they align in the same direction, they can be summed
- can’t go if you have metal
- helpful for neurodegenerative diseases
1.5T vs. 3T vs. 7T
- the number represents the strength of the magnetic fields
- 1.5T is the most common
- 7T is great for cutting edge research (better look at substructures)
T1 vs T2
refers to the sequence
- T1w is great for anatomical structure
- T2w is great for detecting fluid-filled structures and edema
Electroencephalography
records continuous brain activity from thousands of neurons
- measure random ongoing negative and positive electrical activity
- problem: pick up on everything
- high temporal, low spatial
Event-related potentials
changes in EEG activity in response to stimulus
- hard to detect because it is mixed with other signals
- presented multiple times and averaged
- represents cognitive and sensory processing
dynamic brain imaging
measures cognitive activity through blood, oxygen and glucose
Positron emission tomography
measures metabolic activity in the brain by indirectly detecting changes in blood flow
- a person is injected with a radioactive tracer
- PET cameras image multiple parallel brain slices simultaneously
- can detect the decay of hundreds of different tracers
fMRI
accurately measures changes in magnetic properties in the blood when the brain becomes active
- the BLOOD (blood oxygen level-dependent) contrast provides an index of the brain’s relative activity
resting state fMRI
collected when people are asked to stare at a fixed object
- these waves of activity form recurring elements or motifs indicating functional connectivity among cortical systems
- can identify brain connectivity issues in areas associated with disease and disorders
optical tomography
operates on the principle that an object can be reconstructed
functional near-infrared spectroscopy: reflected light infers blood flow
- the amount of light absorption will reflect the brain’s oxygen consumption
- if you are engaged in a task you are going to have more oxygen in the frontal lobe
disadvantage: doesn’t tell you deep structures
magnetoencephalography (MEG)
measures magnetic field from neuronal activity
- magnetic sensors detect this activity and map it onto specific brain regions
- provides timing and some spatial information
can be used to observe the brain’s spontaneous activity or the brain’s response to stimuli
- helps detect and localize epileptic seizures
- often combined with MRI, MSI or magnetic source imaging
two main uses:
- preoperative brain imaging and epilepsy surgery
2 ways to measure neurotransmitters
- indirectly through brain imaging.
- microdialysis: used to measure neurotransmitter levels directly within specific regions of the brain or other tissues
slowly adapting receptors
will continue to respond as long as the stimulus is present
rapidly adapting receptors
detect if something is present and is easy to activate, but the response decreases if the stimulus is maintained
exteroceptive receptors
tell us what is happening in the wordl around us
interoceptive receptors
tell us what we are doing (internally)
where are sensory messages modified
neural relays
(inhibit or amplify)
topographic map
represents the neural-spatial pathway representation of the areas of the sensory world (some areas such as the hands have a higher density)
how does vision work
light enters through the cornea, goes through the lens, and then bent towards the photoreceptors in the back of the eye, after passing through the nerves the signal goes through the optic chasm where the visual fields of both eyes go to opposite hemispheres
photo receptors
specialized neurons
rods: sensitive to dim light
cons: sensitive to colour
geniculostriate pathway
involved pattern, colour and motion recognition
- the back of the cortex represents the central visual field, and the front of the cortex represents the peripheral field
tectopulvinar pathway
involved with detecting and orientating to visual stimulation
- provides information to the cortex about the absolute spatial location of objects
hearing
taking pressure waves and creating meaning
sound localization
identifying the source of air-pressure waves
echolocation
identifying and locating objects by bouncing sound waves off them and detecting the complexity of air-pressure waves
pinna
the external part of the ear, which catches the air-pressure waves and directs them into the ear canal
external ear canal
vibrates and amplifies the waves and directs them into the brain
ossicles
send vibrations to the oval window
cochlea
contains auditory receptors which sends the action potential to the brain
higher frequency sounds
cause maximum peaks near the cochlear base
lower frequency sounds
cause maximum peaks near the apex
inferior colliculus
plays a role in orientation to sound location and is connected with the visual pathway
the ventral auditory pathway
identifies sound
the dorsal auditory pathway
identifies spatial source
nociception
the perception of pain, temperature and itch
- when damaged nerves secrete chemicals producing action potentials
hapsis
allow us to identify objects we touch
proprioception
the perception of body location and movement
posterior spinothalamic tract for hapsis and proprioception
projects to the primary somatosensory cortex and the primary motor cortex
anterior spinothalamic tract for nociception
projects to the primary somatosensory cortex
somatosensory cortex
3a = position and movement of muscles
3b = slowly and rapidly adapting skin receptors
1 = rapidly adapting skin receptors
2 = deep pressure and joint sensation
taste
chemicals in food dissolve and dispense through our mouth to taste buds
smell
- receptor hair cells
- supporting cells
- underlying layer of basal ganglia cells
vestibular system
contains interoceptive receptors in the inner ear
- the ear contains three semicircular canals orientated in three planes
- otolithorgans detect the head position
simple movement
motor cortex
complex movement
all four regions
posterior
specify the goal
prefrontal
plan movement
premotor
start movement
motor
excute movement
corticobulbar tracts (spinal cord pathway)
go to the brainstem, take part in controlling facial movements
corticospinal tracts (spinal cord pathway)
go to the spinal cord, take part in controlling limbs, digit and body movements
motor neurons
connect to all the muscles
lateral motor neurons
project to muscles that control hands and fingers
intermediate motor neurons
project to muscles that control the arms and shoulders
medial motor neurons
projects to muscles that control the trunk
