Flashcards in Final Review Deck (58):
What does attention do?
Selectively increases performance on perceiving and acting on stimuli that are attended to.
What types of visual-spatial attention are there? How do they differ?
There are overt and covert attention. Overt attention involves actual orientation towards the stimulus, while covert attention does not.
How do interesting stimuli grab our attention?
Activation of the superior colliculus. If activation is strong, a saccade is made. If activation is weak, covert attention is directed.
How does voluntary spatial attention affect neurons?
Neurons whose receptive fields are in the attended area fire more strongly to their preferred stimuli.
What brain area appears to direct voluntary attention?
The frontal eye field.
How is EEG relevant to attention?
EEG desynchronization is caused by wakefulness and arousal, while EEG desynchronization is caused by drowsiness and sleep.
Stimulation of what brain area causes arousal?
The reticular formation, probably caused by noradrenergic axons in the locus coeruleus, and cholinergic peribrachial neurons.
What is the locus coeruleus? What does it affect?
This small brain area in the reticular formation has noradrenergic neurons with wide projections to the cortex, and they are activated by arousing stimuli.
What happens when a neuron is exposed to norepinephrine? Are there exceptions?
Most neurons decrease their background firing rate and increase their responsiveness to their preferred stimuli, while high levels of NE in the prefrontal cortex cause general activity suppression.
How can sleep be divided?
Into slow-wave sleep, where EEG is highly synchronized, and REM, where EEG is desynchronized similar to wakefulness.
What is SWS caused by?
Intrinsic neuronal rhythims and the loop between the neocortex, dorsal thalamus, and thalamic reticular nucleus.
How is waking from sleep induced?
Activation of basal forebrain cholinergic neurons, which receive input from the locus coeruleus, glutamatergic peribrachial neurons, and hypocretin neurons of the hypothalamus.
Which neurons in the brain are more active during sleep?
A subset of neurons in the ventrolateral preoptic area, which reciprocally inhibit areas of the brain that promote wakefulness.
What is muscle atonia during REM caused by?
Hyperpolarization of motor neurons, caused by activity of the subcoeruleus region.
What leads to hemispatial neglect?
Damage to the right inferior parietal cortex.
What does damage to the right inferior parietal cortex cause?
Hemispatial neglect of the left side.
How are lethal injections administered?
An anasthetic, followed by a paralytic to prevent spasticity, followed by KCl to stop the heart.
What are the forms learning and memory can take?
Procedural (like riding a bike), semantic (facts you can remember without knowing where they came from), and episodic (episodes you can replay in your mind).
What damage did HM have?
Bilateral lesioning of the hippocampus, amygdala, and some surrounding cortex.
What area of the brain is necessary for object recognition memory?
The perirhinal/postrhinal cortex, not the hippocampus.
What area of the brain is important for remembering relationships between ideas and objects?
What is the hippocampus connected to?
It is connected reciprocally to the perirhinal/postrhinal cortex, which is reciprocally connected to the entorhinal cortex, which is reciprocally connected to other parts of the neocortex.
What is special about the CA3 region of the hippocampus?
These neurons can form autoassociative networks (Hebbian networks), and form a neural substrate for memory.
What does reactivation of CA3 assemblies cause?
Potentially, it causes reactivation of neocortical regions that were active while generating that CA3 assembly (experiencing a memory), leading to recall.
What is the main thrust of the standard model of memory consolidation?
Neural assemblies in the hippocampus lead to the creation of neural assemblies in the neocortex, and memories are eventually "moved" from the hippocampus to the neocortex in this way.
What is auditory fear conditioning? How is fear measured?
Animals learn to associate a specific tone with a shock, and fear is measured by quantifying their freeze response after the tone.
What is contextual fear conditioning? How is it measured?
Animals learn to associate a specific place with pain, and this is measured by quantifying their freeze response in that place.
How many trials does it take for rats to avoid locations they experienced pain?
Usually just one.
What brain regions are involved in learning what makes rats sick?
The basolateral amygdala complex, as well as the hippocampus.
Are memory specialists unique in what they can remember?
Yes, some can remember visual scenes, others can remember events that happen to them, etc.
Does PTSD have a genetic component?
What do frontostriatal loops consist of?
Neocortex -> Striatum -| Pallidum -| Thalamus -> Neocortex. The striatum also self-inhibits.
What is the frontostriatal system useful for?
Selecting context-appropriate behavior.
What neurons is the striatum composed of? What neurotransmitter do they use?
Medium spiny neurons, which use GABA as their neurotransmitter.
What does the indirect loop through the striatum do?
It is responsible for regulating behavioral selection.
What is the ventral striatum involved in? Dorsal striatum?
The ventral striatum is involved in more high-level goal pursuits, while the dorsal striatum is involved in the low-level execution of actions and movements that lead to those goals.
What is Parkinson's caused by?
Massive death of dopaminergic neurons that innervate the striatum.
What does dopamine do in the frontostriatal system?
It excites neurons that inhibit the pallidum and inhibits neurons that take the indirect path.
What does dopamine depletion cause?
An increase in pallidum activity, which leads to overall less activity in the frontostriatal loops.
What is wrong with dopamine-deficient mice?
These mice lack motivation and are unable to perform behaviors.
What does excessive activation of dopamine D1 receptors lead to?
Behavior stereotypy, or repeating the same behavior needlessly, as is the case with 'taffy pulling' in mice.
What do cocaine and amphetamines do?
These drugs directly affect the amount of dopamine available in the brain.
What is instrumental conditioning? What brain regions are involved?
Instrumental conditioning is learning what behaviors lead to specific actions, and it involves the striatum and other brain areas connected to it.
What are phasic increases of striatal dopamine caused by?
Either unexpected rewards, or anticipation of an expected reward.
What does dopamine do to corticostriatal connections?
Dopamine increases the likelihood of LTP in these areas, allowing for learning to take place.
Can information pass between the two frontostriatal loops?
Yes, typically from the ventral striatum to the dorsal striatum (higher to lower level).
What is the prefrontal cortex responsible for?
Mostly prepotent behavior suppression (inhibiting the most obvious and salient desired behavior in a given situation). It is also responsible for working memory.
How many prefrontal lobotomies were performed? When?
Over 40,000 prefrontal lobotomies were performed in the 1940's and 50's.
How do people with prefrontal lobotomies act?
They tend to act impulsively and have a hard time pursuing long-term goals.
What experimental tasks can be used to test prefrontal cortex function?
The Wisconson card and Stroop tests would be good candidates.
What is cool about some neurons in the prefrontal cortex?
They are able to maintain their firing rate after being exposed to a specific stimuli, and this is cool because it may be the neural substrate of working memory.
How are functions of the prefrontal cortex patterned? Where is this gradient paralleled?
Anterior-to-posterior, higher to lower level. This gradient has a parallel in the striatum.
Why are certain animals selected for studying?
Normally because they are the easiest to study.
What areas, when lesioned, lead to language difficulty?
Broca's and Wernicke's area.
What is sexual differentiation caused by?
Exposure during development to high levels of specific hormones, as well as some direct chromosomal effects.
Why is brain imaging uncertain?
Because different people have different-sized brains and different-sized brain areas.
What is autism's monozygotic coincidence? Dizygotic?
90% and 30% respectively.