Topic 2 - Cognitive Neuroscience Flashcards
VEP
visual evoked potential
Which machine produces VEP? How?
electroencephalography EEG
—> ERP (event related potential)
—-> VEP
By focusing on the object of interest, the VEP acts as a way of
confirming your selection. Evokes a large potential when focusing.
For individuals with severe communication problems, this is potentially a way of communicating via the eyes alone.
A patient in a vegetative state (‘locked-in’) as a result of a road traffic accident was asked to imagine playing tennis and imagine walking round their house. Differential brain activity was produced.
SMA
PMC
PPC
PPA
SMA =
PMC =
PPC =
PPA =
SMA = supplementary motor area PMC = premotor cortex PPC = posterior parietal-lobe PPA = parahippocampal gyrus
What was the difference i brain avit5ivty between a normal person and the person locked in vegetable state?
Normal controls’ brain activity was “indistinguishable” (p. 1402) from the activity of the locked-in patient.
Normal controls’ brain activity was “indistinguishable” (p. 1402) from the activity of the locked-in patient. Therfore?
this evidence of conscious awareness in an unconscious individual?
Parts of the neuron
- dentrites
- soma
- axon
- terminal button
- synapse
- dentrites
- soma
- axon
- terminal button
- synapse
FUNCTIONS ???
DENDRITE
Absorbs chemical stimulation from other neurons
SOMA
If dendritic activity is large enough an electric action potential will be fired
AXON
Conducts the electrical signal to terminal buttons at the end of the axon
TERMINAL BUTTON
Turns the electrical signal back into a chemical squirt
SYNAPE
The jump the chemical has to made to be taken up by the next dendrite
By attaching microelectrodes to _______, we are able to observe ..
AXONS, we are able to observe individual action potentials rather than large ensemble activity.
The whole process of going from baseline, to depolarization, repolarization, refractory period back to resting state takes about
5 ms.
What are the phases of an action potential?
Baseline (-70) Depolarization (+40) Repolarization (-70) Refractory period (below -70) Resting state (-70)
Does the magnitude of the AP change with function of sensory input?
NO, the magnitude stays exactly the same, the frequency that the AP are fired at does change as a function of sensory input.
Differences in the sensory environment are coded by
changes in the rate of axon firing
FEATURE DETECTORS
Types
Simple cells
Complex cells
End-stopped cells
Simple cells
respond to size, orientation, colour
Complex cells
respond to orientation and direction
End-stopped cells
respond to orientation, direction and size
cats were only exposed to light in a vertically stripped cylinder for 5 hours a day. Wat were their neurons responses?
neurons were only responsive to orientations they had previously been exposed to. These cats were essentially ‘blind’ to vertical and oblique lines.
exposed cats from birth to horizontal lines in one eye and vertical lines in the other eye.
What were thier neurons responses?
Single cell recordings revealed very specific neural sensitivity. Neurons had not generalised to oblique orientations, nor to orientations that the other eye had learnt.
Depending on how neurons connect and talk to one another, a form of _______________ arises.
hierarchical processing
hierarchical processing
This is where more and more complex
combinations of information can be
represented
Groups of neurons in the temporal lobe help to code specific examples of
stimuli in the environment. Visual faces, auditory frequencies, olfactory odours might all be sparsely coded.
Dorsal and ventral spans across where of the brain
From bottom to top of the entire head/brain
Lateral and medial spans across where of the brain
From left to right sides of the brain/head
Anterior and posterior spans across where of the brain
Form front to back of the brain/head
What are the three main portions of the brain?
Forebrain
Midbrain
Hindbrain
FOREBRAIN
- Hypothalamus involved in hormone release and appetite.
- Limbic system includes amygdala and hippocampus.
MIDBRAIN
Includes reticular activation system, which controls consciousness, heartbeat…
HINDBRAIN
Basic biological functions controlled here such as swallowing and digestion.
Cerebral cortex is made of what
4 lobes