Task 7 Flashcards
What functions is the amygdala involved in?
Emotion, reward, motivation, learning, memory, and attention
What are the properties of rewards?
Sensory, affective, and motivational properties, each represented in the brain
How is emotion defined in the context of amygdala function?
Reactions to stimuli, including autonomic and skeletal motor responses
What is the difference between valence and affect?
Valence refers to the direction of value assignment (positive or negative),
while affect collectively refers to neural representations and processes related to emotion
Where is the amygdala located?
In the anterior temporal lobe towards the medial side, appearing almond-shaped
What is a common misconception about the amygdala’s function?
That it is only involved in processing negative emotions; it also plays a major role in positive affect and reward processing
How does the amygdala contribute to positive affect?
By encoding and updating the value of rewards and contributing to conditioned responses like cardiovascular changes during anticipation
How do amygdala neurons encode valence?
They encode positive or negative value independent of the image, with distinct populations for positive and negative valence
What role does the amygdala play in learning through stimulus-valence pairing?
Changes in associative encoding in amygdala neurons are responsible for learning, as shown by altered neuronal activity corresponding to changing stimulus-valence pairings
How do monkeys with lesioned amygdalas respond to high-incentive food?
They lack conditioned cardiovascular responses during the anticipatory period but continue to show skeletomotor and consummatory responses
What is the role of the amygdala in stimulus-reward association?
It is not required for linking stimuli with reward but is essential for linking stimuli with the current value of rewards
How do monkeys with amygdala lesions react to threats like fake snakes?
They show little or no emotional reaction to snakes, indicating the amygdala’s role in emotional reactions to threats
How is the human amygdala sensitive to emotional descriptions?
The right amygdala is selectively sensitive to pictures associated with positive or negative emotional descriptions compared to neutral ones
What does the framing effect demonstrate about human decision-making?
Human choices are influenced by how options are presented, showing systematic biases due to an affect heuristic underwritten by an emotional system
How does the amygdala respond to framing effects in decision-making tasks?
Increased amygdala activity is associated with risk-averse behavior in gain frames and risk-seeking behavior in loss frames
How does the orbitofrontal cortex (OFC) relate to framing susceptibility?
People with lower susceptibility to framing effects show higher OFC activity, integrating emotional and cognitive information for decision-making
What role does the anterior cingulate cortex (ACC) play in decision-making?
It detects conflict between analytical response tendencies and emotional amygdala-based systems
How do amygdala lesions affect reward expectancy and decision-making?
Lesions impair the generation of expected reward signals and behavioral choice signals based on expected reward
but do not affect the processing of reward outcomes
What task was used to study reward-related learning and decision-making involving the amygdala?
A probabilistic reversal task where subjects chose between two stimuli, with reward and punishment contingencies that reversed after correct choices
How did patients with amygdala lesions perform in probabilistic reversal tasks compared to controls?
They showed a specific insensitivity to reward value in guiding choices, with more frequent switching behavior following rewards
What differences in brain activation were observed between control subjects and amygdala lesion patients during decision-making? (Study: H, determinisitic,probalistic)
Control subjects showed greater anterior insula and posterior lateral OFC activation in response to negative feedback compared to patients
How does the amygdala influence expected reward signals in the vmPFC?
The amygdala plays a critical role in processing expected reward value signals in the vmPFC, which are abnormal in lesion patients
What is the primary contribution of amygdala-vmPFC interactions in decision-making?
Computing expected reward values that guide behavioral decisions
What is the proposed model of amygdala function regarding its interaction with the OFC?
The amygdala updates the value of expected rewards,
The OFC stores these values to guide future behavior based on current value assessments
How does the amygdala enhance sensory processing in the rhinal cortex?
Amygdala neuron firing, particularly after unexpected rewards, facilitates impulse transmissions between perirhinal and entorhinal cortex neurons, enhancing sensory processing
What role does the amygdala play in memory processing?
It facilitates hippocampal-dependent information storage, enhancing the processing and storage of emotional memories
What is the significance of the reciprocal connections between the amygdala and neocortex (OFC) and sensory areas (IT/PRh)?
These connections enable the integration of affective and sensory information, essential for goal-directed behavior and decision-making
How does the amygdala respond to social cues?
It generates arousal signals and encodes stimulus-valence associations, affecting behavior even when the associations are not consciously perceived
What role does the amygdala play in anticipatory autonomic and neuroendocrine responses?
It mediates these responses, contributing to the anticipation of high-incentive rewards
How do amygdala lesions affect performance on stimulus-reward association tasks?
Lesions do not significantly impair stimulus-reward association tasks
they affect the processing of the current value of rewards
