Midterm #1 Flashcards
Charles Bonnet Syndrom - Symptoms
symptoms include consciousness about hallucinations that stem from some sort of physical or emotional stress in patients that recently went partially or fully blind. These were mainly visual experiences
reason: the brain is making up for lack of activity in the primary cortex
Charles Bonnet Syndrome - Neural Basis
Damage to V4 area or low blood flow to the area, mainly damage higher up in the visual system
Planes and describe them
Sagittal, Axial, Coronal
Frontal Lobe (where)
In charge of motor control, and higher cognitive functions
Parietal Lobe (where)
Sensation of the body and controls spatial aspects of other senses
Temporal Lobe (where)
In charge of audition, object recognition and identification
Occipital Lobe (where)
In charge of vision
Gyrus v sulci
gyrus is the folding patterns, outward pieces and the sulci are the tucked in valleys
White matter vs grey matter
White matter needs to connect grey matter to itself, white matter makes the longer connections and grey matter makes the closer connections
Cerebellum
Attached to the back of the pons and the brainstem
It controls balance and movement and is involved with error recovery when the movement does not go the right way
Thalamus
There are two sides, this relays sensory information to higher areas in the brain
includes a variety of nuclei
Hyperpolarization
becoming more negative than the baseline
Repolarization
returning to the baseline polarization level
Cochlea
analog of the retina and it is where the sensory transduction occurs in each ear
Synesthesia
atypical or multisensory experience where one’s sensory experience is related to another sensory experience and usually occurs in higher up senesory areas
Basilar Membrane
Exposed to fluid waves triggered by vibrations of the oval window.
Fluids of different vibrations will cause different parts of the basilar membrane to vibrate which creates a tonotopic map of the incoming frequencies
Contains small hair cells that transduce sound into electrical signals that are interpreted by the CNS
Nuclei
Grey matter or cell bodies
Source coding
when IT neurons are fired specifically for a certain stimulus and is usually when one is more familiar with that stimulus (seeing a face)
Population coding
when IT neurons are fired in many different places and degrees when seeing a stimulus and is usually when the stimulus is less familiar
Rods vs cones
rods: sensitive to light (really dark) vs cones: seeing fine details and less sensitive
Mach Bands
the phenomenon that when we are looking at the end of a band/shade of colors it appears darker when next to a darker color or shade and lighter when next to a lighter shade or color…
This is because of the receptive field of the ganglion cells. Essentially, it is in a center-surround organization. When you look at the edge of a band, lets say when a darker band is next to a lighter band then the inhibitory area that is on the lighter band might appear darker … the inhibitory area of the cell overlaps on the darker side of the Mach band thus making the edge of the lighter side lighter.
Lesion Studies
Experimental study of people who have had strokes to determine relationships between cognitive abilities of interest and underlying brain matter
i.e. stroke, tumor, degenerative diseases
Connectional Methods
How different parts of the brain are sending messages back and forth… How the input and output are used to understand the function
i.e. diffusion tensor imaging (DTI), invasive tracer substance
Correlational Methods
Making observations while one performs behavior
i.e. MRI, fMRI, EEG
Stimulation Methods
stimulating neural circuit and seeing its effect on behavior i.e. Transcranial Magnetic Stimulation (TMS)
Grey matter
cell bodies of neurons and local connections
White matter
long distance connection between neurons
What makes up the Limbic system?
amygdala, hippocampus, formix and mamillary bodies,
How do action potentials work? Describe the curve
- First, the neruon is still at the resting potential
- Next is the summation of EPSPs (depolarization) –> incremental
- Then there is an influx of sodium (Na+) into the cell and the graphed lines go up as the sodium ion channels are opening
- Then on the come down there is an efflux of potassium (K+)
- Then the refractory period occurs and the neuron mV dips down below the threshold as hyperpolarization occurs
- Return to the resting potential
Excitatory postsynaptic potential (EPSP)
When positive ions (like Na+) flow through a receptor into the cell
Depolarization of the postsynaptic cell
Inside of cell becomes more positive –> more positive means more voltage
Increase the probability of an action potential
Inhibitory postsynaptic potential (IPSP)
If neurotransmitter binding causes the potential difference in voltage between the inside and outside of the cell to grow larger
Occurs when positively charged (Ka+) flows out of the cell or when negatively charged chloride ions flow into the cell
Hyperpolarization
Inside of the cell becomes more negative (more than it usually is which is why it dips –> more negative means less voltage)
*Decrease the probability of there being an action potential
Depolarization
The cell becomes more positively charged.
Na+ neurons flow into the cell and K+ ions flow out
Explain the resting state of a neuron
There are more negative charged elements on the inside rather than on the outside (inside of cell is more negative)
the neuron at rest has a negative charge
Synaptic transmission
the release of neurotransmitter by the presynaptic neuron –> this affects the membrane potential of the postsynaptic neuron
- chemical neurotransmitters released within the synapse ion channel designed to match up
- the voltage of the second neuron can become more positive or less positive
myelin
is produced by glial cells
is what creates white matter –> this is why white matter can make larger and farther away connections
the insulation allows for the preservation of passive code flow
makes transmitting more efficient/faster
but this can’t be everything because myelinated areas
do not go through the action potential process
Voltage
separation of charged particles
Ramon Y Cajal
before, people thought that neurons weren’t individual cells but through staining techniques (Golgi) he proved that neurons were discrete cells and have a dynamic polarization (flow in predictable direction)…
before people thought it was a continuous web
Sensation vs perception
Detection of signal vs how we make sense of that signal
Ventral Stream
helps us recognize what objects are and occurs in the higher vision areas
leads to temporal lobe and is concerned with object recognition
Dorsal Stream
helps us recognize where objects are and occurs in the higher vision areas
leads to the parietal lobe and helps us understand spatial location
Types of damage that occur in each visual system? Name the function of each visual system
V1=blindness
V2=visual agnosia
V3=specific problems like face blindness or issue seeing motion
Lateral Geniculate Nucleus
The part in the thalamus that receives major sensory input from the retina
Basil Ganglia (location)
A part of the limbic system that is involved in initiating, maintaining, terminating activity in the frontal cortex specifically –> facilitates motor control
Amygdala (location)
Associated with rapidly processing perceptual input and influencing the internal states of the body (i.e. emotion)
located anterior to the hippocampus
Hippocampus (location)
Associated with episodic memory and spatial navigation
located posterior to the amygdala
Hypothalamus (location)
Located inferior to the thalamus
important for homeostasis and basic survival drives
Hodgkin Huxley Cycle (location)
Positive feedback loop allowing for rapid depolarization
Synaptic potential or receptor potential
Cycle of
1. membrane depolarizing
2. voltage-gated ion channels opening
3. Na+ flows into neuron
Saltatory Conduction (location)
Passive conduction with myelinated segments and regeneration of action potentials at nodes of Ranvier
- Action potentials at axon hillock and each node
- Passive flow through each myelinated segment
Cell layers in the retina?
(from back to front) Photoreceptors (rods and cones), bipolar cells and ganglion cells
McGurk Effect
a perceptual illusion where what they see influences what they hear … shows how we use many different senses in order to guide our perception of the world.
How does sound go through the middle ear and what is the function?
Pinnea –> ear drum –> middle ear (ossicles_ which transfers energy from the larger window of the eardrum to the smaller oval window ] the job so far is to shape the sound in the environment
how do the inner hair cells work in the basilar membrane?
opening and closing the Ka+ channels … the movement of the hair cells can increase or decrease the force on the top links
all or none action potential
a neuron either reaches the threshold or doesn’t –> will never fire between
Action potentials are caused when different ions cross the brain
