Brain & Behavior Final Exam Study Set

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What is the purpose of sleep?

Needed for brain to remove any harmful substances that build up throughout the day, and to replenish neurotransmitters

What is sleep?

Natural, easily reversible, periodic state of many living things in which you are not aware of surroundings, have low arousal, and have a distinct change in brain activity

How is sleep monitored?

EEGs are used, which is where electrodes are placed on head to measure electrophysical activity from the brain and muscles in the face and around the eyes

What is the difference between synchronous and desynchronous EEG activity?

Synchronous = Neurons active at the same time, show as a large, clear wave in EEG

Desynchronous = Neurons active at random, show as small, chaotic waveforms without a clear pattern in EEG

What are the 4 stages of sleep?

1) NREM sleep, consists of theta activity

2) NREM sleep, contains sleep spindles and k-complexes

3) Slow wave sleep, consists of delta activity

4) REM sleep, consists of theta and beta activity

What specific proteins are removed from the brain during sleep?

Beta-amyloid and tau

Which neuromodulators are high during wakefulness, and low during sleep?

Dopamine, norepinephrine, serotonin

What is the role of acetylcholine during sleep?

This regulates sleep and maintains the periodicity of sleep (essentially your circadian rhythm). Specifically the basal forebrain produces acetylcholine!

What is consciousness?

The internal awareness of sensations, perceptions, thoughts, and feelings, it is our first-person, subjective narrative

What is the mind-body problem?

A debate over whether or not the functions of the mind are entirely accounted for by the physical activities of the brain. There are two dominating ideas in this problem: Dualism and Monoism

Monoism = Yes

Dualism = No

What do stimulants do to sleep in the brain?

It prevents slow wave brain activity by increasing neuromodulator activity

What do sedatives do to sleep in the brain?

Increases slow wave brain activity by decreasing neuromodulator activity

What is the role of the limbic system when it comes to emotion?

It processes emotion and includes the cingulate cortex, hippocampus, amygdala, hypothalamus, and ventromedial prefrontal cortex.

What is the role of the amygdala when it comes to emotions?

It processes emotions and makes you aware of them occurring

What is the role of the hypothalamus when it comes to emotions?

It processes how emotions feel in the body/how emotions are manifested/executed in the body

What is the role of the ventromedial prefrontal cortex when it comes to emotions?

This modulates/mediates emotions

What happens when the amygdala is damaged?

Can result in reduced sense of negative emotions, such as fear, and can also result in not recognizing these emotions in others

What is the lateral nucleus?

The gatekeeper of the amygdala that decides what gets output into the rest of the amygdala

What are the components of an emotional response?

Behavioral component (consists of muscular movements that are appropriate to the situation that elicits them), Autonomic responses (facilitates the behaviors and provides quick mobilization of energy for vigorous movement, and hormal responses (reinforces the autonomic responses)

What does the smaller nucleus in the amygdala do?

Sends information from the amygdala to the hypothalamus

What is the role of the hypothalamus?

Maintains daily/night cycles, regulates body temperatures, controls appetite and thirst, manages sexual behavior, releases hormones, regulates sympathetic and parasympathetic systems

What is the role of the paraventricular nucleus (PVN)?

Releases stress hormones (cortisol) that go from PVN → central amygdala → anterior pituitary (ACTH) → adrenal gland, that amplifies the entire fear response

What is the role of cortisol?

Increases blood sugar, increases blood pressure, and suppresses the immune system

What is the role of the lateral hypothalamus (LHA)?

Activates the sympathetic nervous system

What is the purpose of learning?

It allows us to acquire new information by having experiences change our nervous system and our behavior. In particular, learning something new and creating a memory physically changes the structure of the nervous system, altering neural circuits that participate in perceiving, performing, thinking, planning, and behaving

What is plasticity?

The concept that learning something new and creating a memory physically changes the structure of the nervous system

How does remembering things work?

It is a process of specific representations getting stitched together in real time

What are the mechanisms of synaptic plasticity?

Synaptic potentiation/strengthening (forms the content of learning/memory through activation of NMDA receptors, and inclusion of more neurotransmitters receptors) and neuromodulators as reinforcement signals (increases placisity/rate of learning and increases protein of NMDA receptors in strengthening co-active synapses)

How does specificity in synaptic plasticity work?

Individual neurons for very specific memories/actions go to different motor neurons depending on what you learned, which means plasticity can lead to differences in reactions if conditioned

How do drugs affect learning mechanisms?

All major drugs of abuse increase dopamine, which induces the immediate “high” feeling that then potentiate sensory-motor associates that were active at the time of drug use. This then means that experiencing those situations without the high that drugs cause leads to dopamine withdrawal

How do neural circuits of withdrawal work?

Electricity releases serotonin that makes NMDA receptor ready to perform. Reinforcement signals then act by increasing synaptic plasticity when there is an unexpected reward, and decreasing with an unexpected punishment

What is the difference between positive reinforcement and negative reinforcement?

Positive = reward for behavior

Negative = punishment for behavior

How does dopamine work as a reinforcement signal?

If there is no prediction of a reward and the reward occurs → dopamine releases at reward

If there is a reward predicted and the reward occurs → dopamine releases before reward is recieved

If there is a reward predicted but the reward does not come → dopamine activity goes down

What is the difference between top-down and bottom-up processing?

Top-down processing: Starts with prior knowledge, experiences, and current goals that then affect our perception

Bottom-Up processing: Starts with sensory input → feature extraction → perception

What is the role of the prefrontal cortex?

Is in-charge of executive functions (goal direction) such as working memory, motor planning, inhibitory control, and attention

What is the role of working memory?

It is responsible for temporarily holding information “in mind” available for processing that is used to maintain persistent goal-direction and deploy “mediational” or cognitive processes of attention, motor planning, and inhibitory control. It is essentially the persistent firing of prefrontal cortex neurons

What is impulse control?

The ability to suppress habitual or dominant behavioral responses (prepotent responses, impulses) in order to select more goal-directed behaviors

What is the difference between overt attention and covert attention?

Overt attention: Directing one’s gaze to fixate on an object or region of attention

Covert attention: Attending to an object or region of space without shifting one’s gaze (peripheral vision)

What are David Marr’s 3 levels of analysis?

1) Computational level - what problem is the system solving? (Goal of behavior/computation and why does the brain perform it?)

2) Algorithmic level - What representations and rules solve the problem? (Information processing)

3) Implementational level - How is the algorithm implemented? (Which neurons, circuits, and molecules implement the algorithm?)

What is action potential?

The electrical charge threshold that needs to be passed in order for a neuron to pass the message it received onto the next neuron

How does action potential work?

It is a transient depolarizing spike of the membrane potential, in which there are multiple phases: An excitatory synapse (neurotransmitter) starts the process and goes into the rising phase (Na+ enters membrane), overshoot (peak of the potential), falling phase (K+ leaving membrane), undershoot (potential dipping slightly below baseline levels), and then back to resting potential

What is the mV that a neuron needs to reach in order for an action potential to occur?

-45mV (allows Na+ channels to open and continue depolarizing membrane), and then needs to reach +40mV in order for potassium channels to open and have the falling phase occur

What are the main excitatory and inhibitory neurotransmitters in the brain?

Excitatory: Glutamate (leads to depolarization in neuron) which is affected by Ketamine + PCP, which links to and blocks NMDA glutamate receptors

Inhibitory: GABA (leads to hyperpolarization in neuron) which is affected by alcohol and benzodiazepines, which binds to GABA receptor and enhances activity of chlorine

How do seizures occur in the brain?

Occurs when an acute electrical disturbance in the brain occurs that produces excessive synchronous activity (aka an imbalance of excitation and inhibition, with not enough inhibition occurring)

How is epilepsy treated?

Medication that targets either sodium channels or GABA is given to patients with this. Medications include phenytoin, carbamazepine, oxcarbazepine, eslicarbazepine acetate, lamotrigice, lacosamide, zonisamide

How do you reduce the function of a neurotransmitter?

Block vesicle fusion (using toxins/venoms) or enact a receptor blockage (using ketamine to block glutamate or blocking dopamine receptors)

How do you increase the function of a neurotransmitter?

Enhance receptor activation (using alcohol to increase GABA), block neurotransmitter reuptake (using SSRIs), disrupting vesicles and reversing transporters (using methamphetamine), and reducing neurotransmitter breakdown (using MAO inhibitors and acetylcholinesterase inhibitors)