Neuro Box 6

In its simplest form, instrumental behavior is shaped by —-

rewards and stimuli that signal reward.

In its simplest form, instrumental behavior is shaped by rewards and stimuli that signal reward.

• This requires a mechanism to represent rewards (—— & ——) and a system for encoding their signals.

(magnitude & valence)

In its simplest form, instrumental behavior is shaped by rewards and stimuli that signal reward.

• This requires a mechanism to represent rewards (magnitude and valence) and a system for encoding their signals.

  • By monitoring how these events are related to behavior, these neural mechanisms can shape what we do, fostering —— and ——

adaptive responses (go) (and) inhibiting mal- adaptive behavior (no-go).

In its simplest form, instrumental behavior is shaped by rewards and stimuli that signal reward.

• This requires a mechanism to represent rewards (magnitude and valence) and a system for encoding their signals.

  • By monitoring how these events are related to behavior, these neural mechanisms can shape what we do, fostering adaptive responses (go) and inhibiting mal- adaptive behavior (no-go).

• These processes alone seem sufficient to guide the development of simple habits, where ——

reward is immediate and response options are constrained.

Reward =

the immediate advantage accrued by the outcome of a behavior

Value = 

an estimate of how much reward, or punishment, will be gained from the choice, both now and in the future

To organize behavior in such complex situations, the organism must represent not just reward , but also ——

its value

working memory =

extends instrumental behavior to problems related to goal setting and planning, to help us understand how humans make choices that balance long-term gains with short-term costs

(Reward & Value)

To weigh these alternatives requires a form of——

(of) working memory

neuroeconomics = a

discipline that draws from neuroscience, economics, and psychology, to explore the brain mechanisms that underlie decision-making and choice

The aim in neuroeconomics is to —-

couple behavioral data with neurobiological observations

(neuroeconomics)

In animal subjects:

• explored using techniques that disrupt function (lesion) in a particular region 

• or involve recording from neurons using electrodes that have been lowered into the brain.

Why has progress in the neuroeconomics area has been slow?

Unless warranted by medical concerns, such procedures cannot be used with humans

What was a major turning point in the study of neuroeconomics?

the development of a non-invasive method to image the brain using functional magnetic resonance imaging (fMRI)

(How the fMRI works)

The fMRI takes advantage of the fact that —-

brain activity requires oxygen

(How the fMRI works)

The fMRI takes advantage of the fact that brain activity requires oxygen, which is transported in the blood by —-

hemoglobin

(How the fMRI works)

The fMRI takes advantage of the fact that brain activity requires oxygen, which is transported in the blood by hemoglobin ——→ When hemoglobin binds oxygen to form —?— —→it alters the magnetic properties of the molecule.

oxyhemoglobin 

(How the fMRI works)

The fMRI takes advantage of the fact that brain activity requires oxygen, which is transported in the blood by hemoglobin ——→ When hemoglobin binds oxygen to form oxyhemoglobin ——-→ ——-?——

it alters the magnetic properties of the molecule

(How the fMRI works)

The fMRI takes advantage of the fact that brain activity requires oxygen, which is transported in the blood by hemoglobin ——→ When hemoglobin binds oxygen to form oxyhemoglobin ——-→it alters the magnetic properties of the molecule.

It is this change that is detected within the fMRI device, allowing researchers to ——

monitor the flow of oxyhemoglobin within the brain

(How the fMRI works)

The fMRI takes advantage of the fact that brain activity requires oxygen, which is transported in the blood by hemoglobin ——→ When hemoglobin binds oxygen to form oxyhemoglobin ——-→it alters the magnetic properties of the molecule.

It is this change that is detected within the fMRI device, allowing researchers to monitor the flow of oxyhemoglobin within the brain. 

As neural activity increases →

more oxyhemoglobin is directed to the region

(How the fMRI works)

The fMRI takes advantage of the fact that brain activity requires oxygen, which is transported in the blood by hemoglobin ——→ When hemoglobin binds oxygen to form oxyhemoglobin ——-→it alters the magnetic properties of the molecule.

It is this change that is detected within the fMRI device, allowing researchers to monitor the flow of oxyhemoglobin within the brain. 

As neural activity increases →more oxyhemoglobin is directed to the region→

producing a block oxygenation level dependent (BOLD) signal

Using fMRI, researches have shown that the presentation of reward consistently engages neural activity within a common set of neural structures that includes:

• the orbitofrontal cortex (OFC)

• the amygdala

• the striatum

• the nucleus accumbens

The —- and —— are part of the basal ganglia

striatum (and) nucleus accumbens

The striatum and nucleus accumbens are part of the basal ganglia: 

a subcortical cluster of structures that also includes the globus pallidus, adjoining components of the thalamus (the subthalamic nuclei) and a region of the midbrain (the substantia nigra)

The striatum and nucleus accumbens are part of the basal ganglia, a subcortical cluster of structures that also includes:

• the globus pallidus

• adjoining components of the thalamus (the subthalamic nuclei)

• and a region of the midbrain (the substantia nigra)

The striatum and nucleus accumbens are part of the basal ganglia, a subcortical cluster of structures that also includes:

• the globus pallidus

• adjoining components of the thalamus (the ——?—)

• and a region of the midbrain (the substantia nigra)

subthalamic nuclei

The striatum and nucleus accumbens are part of the basal ganglia, a subcortical cluster of structures that also includes:

• the globus pallidus

• adjoining components of the thalamus (the subthalamic nuclei)

• and a region of the midbrain (the ——?——-)

substantia nigra

The orbitofrontal cortex lies —-

directly above the eye sockets (orbits)

The orbitofrontal cortex lies directly above the eye sockets (orbits) and represents ——

the ventral (lower) portion of the prefrontal cortex (PFC)

the basolateral amygdala (BLA) contributes to—-

learning about Pavlovian relations

In instrumental learning, the amygdala plays two important roles:

• Neural activity within this region provides an index of reward magnitude and valence

• Processing within the amygdala can endow neutral cues with an affective code that can motivate behavior and reinforce new learning

In instrumental learning, the amygdala plays two important roles:

• Neural activity within this region provides —-

index of reward magnitude and valence

In instrumental learning, the amygdala plays two important roles:

• Neural activity within this region provides an index of reward magnitude and valence

• Processing within the amygdala can endow neutral cues with——

an affective code that can motivate behavior and reinforce new learning

Drug-paired cues can facilitate drug-taking behavior, and this secondary reinforcement is —— by lesioning the BLA.

(is) eliminated

Lesioning the BLA disrupts instrumental behavior motivated by —-

escape from a fear eliciting cue

In an appetitive task, devaluing a food reward (e.g., by pairing it with an illness-inducing agent) normally reduces instrumental responding.

• Devaluation has no effect on performance in —— subjects.

BLA lesioned

The striatum and its associated nuclei provide —-`

a system for integrating positive and negative outcomes over multiple trials, to modify behavioral habits.

The striatum and its associated nuclei provide a system for integrating positive and negative outcomes over multiple trials, to modify behavioral habits.

Research suggests that it does so through two pathways that project to the thalamus:

• a direct path that sends a “go” signal to facilitate the execution of a response

• an indirect path that sends a “no-go” signal to suppress competing responses

The striatum and its associated nuclei provide a system for integrating positive and negative outcomes over multiple trials, to modify behavioral habits.

Research suggests that it does so through two pathways that project to the thalamus:

• a direct path that sends a “go” signal to ——

facilitate the execution of a response

The striatum and its associated nuclei provide a system for integrating positive and negative outcomes over multiple trials, to modify behavioral habits.

Research suggests that it does so through two pathways that project to the thalamus:

• a direct path that sends a “go” signal to facilitate the execution of a response

• an indirect path that sends a “no-go” signal to ——

suppress competing responses

two pathways that project from the striatum to the thalamus:

• a direct path that sends a “go” signal to facilitate the execution of a response

• an indirect path that sends a “no-go” signal to suppress competing responses

These differential effects are mediated, in part, by the action of the neurotransmitter ——- 

(neurotransmitter) dopamine (DA)

two pathways that project from the striatum to the thalamus:

• a direct path that sends a “go” signal to facilitate the execution of a response

• an indirect path that sends a “no-go” signal to suppress competing responses

These differential effects are mediated, in part, by the action of the neurotransmitter dopamine (DA), which can engage either:

• the excitatory D1 receptor (go)

  • or

• the inhibitory D2 receptor (no go)

two pathways that project from the striatum to the thalamus:

• a direct path that sends a “go” signal to facilitate the execution of a response

• an indirect path that sends a “no-go” signal to suppress competing responses

These differential effects are mediated, in part, by the action of the neurotransmitter dopamine (DA), which can engage either:

• the excitatory —- receptor (go)

D1

two pathways that project from the striatum to the thalamus:

• a direct path that sends a “go” signal to facilitate the execution of a response

• an indirect path that sends a “no-go” signal to suppress competing responses

These differential effects are mediated, in part, by the action of the neurotransmitter dopamine (DA), which can engage either:

• the excitatory D1 receptor (go)

  • or

• the inhibitory — receptor (no go)

D2

DA activity is modulated by —-, providing an ——

predictability, (providing an) error signal that shapes behaviors

Evidence that the striatum is involved in reward comes from studies demonstrating that rats find ——— and ——— within this region highly rewarding.

electrical stimulation (and) DA microinjection

striatal lesions undermine ——-, and increase ——-

habitual responding (and) ,   (increase) sensitivity to reinforcer devaluation

In humans, a loss of DA input from the ——- (an outcome of Parkinson’s disease) causes ——

(the) substania nigra , (causes) a disruption in motor behavior

The OFC lies within the —-, an evolutionarily younger brain region found in humans and higher mammals

(within the) PFC

Research suggests that the PFC plays a role in——

higher brain functions, such as planning and decision making.

The OFC corresponds to the ——— and is anatomically connected with structures implicated in reward, such as the amygdala and striatum

ventral region of the PFC

The OFC appears to provide a form of ——- that allows the organism to weigh the relative value of alternative choices

executive control

Interestingly, there is some evidence for a subdivision of labor within the OFC, with rewarded actions (——?—-) eliciting greater neural activity within the medial regions

(approach)

Interestingly, there is some evidence for a subdivision of labor within the OFC, with punished actions (——?——) engaging more lateral areas

(response inhibition)

Damage to the OFC interferes with learning when ——-

reward contingencies no longer apply

• (e.g., when reinforcer contingencies are reversed)

humans with damage to the OFC cannot use —— to guide their behavior in a gambling task

the value of a predicted outcome