15) Emotions and Limbic System

Question 1

3 factors that allow animals to react adaptively to stimuli?

What are the basic emotions that are innate? (6)

Answer 1

1. Feeling - subjective mental state (cognitive process)
2. Behavior - Facial expressions; Freezing, startling
3. Physiology - Involuntary or subconscious. Product of endocrine, autonomic output systems; Rapidly beating heart, shortness of breath, excessive sweating, cutaneous blood flow (blushing or turning pale), piloerection

Can be innate or learned

Basic Emotions that are innate; Conserved across cultures and species

• Happy
• Angry
• sad
• fearful
• disgust
• surprise

Question 2

What is Valence?

What is arousal?

Study graph

Answer 2

Valence - how positive or negative the emotion is

Arousal - Level of excitement

Question 3

What structure controls our emotional responses?

How do we know this?

Answer 3

Hypothalamus regulates the autonomic expression of emotions through activation of sympathetic system, arousal

• Rapidly beating heart, shortness ofbreath, excessive sweating, cutaneous blood flow, piloerection
• Descending control to brainstem of emotional expression - both autonomic (physiology) and somatic (behavior)

“Sham Rage” - Philip Bard experiments in the 1920’s

• Removed both cerebral hemispheres, underlying white matter and the basal ganglia BUT the hypothalamus was left intact
• Animals acted “enraged” without any stimuli
• No rage response without the hypothalamus

Question 4

What are the differences between voluntary facial paresis and emotional facial paresis?

Answer 4

Voluntary facial paresis - The voluntary control over facial muscles is lost. Cannot produce a voluntary smile, but can produce an involuntary one.

Emotional facial paresis - The involuntary control over facial muscles is lost. Cannout produce an involuntary smile. But can voluntarily produce one.

Question 5

Answer 5

Question 6

Where is the amygdala found?

Where does it have connections with?

What is it responsible for?

What is the amygdalas primary emotion?

Answer 6

Amygdala is found in the anterior, medial temporal lobe. Adjacent to hippocampus

It has connections with the cortex, hippocampus, hypothalamus, etc.

Responsible for:

• relating sensory stimuli with emotional experience
• connectivity with prefrontal cortex required for higher order processing of emotion
• connectivities elsewhere are also required for behavior and associative learning

Primary emotion = fear

Question 7

Patient S.M. cannot physically feel fear, why?

What are some of her strange behaviors?

Answer 7

Patient S.M. lost her amygdala due to Urbach-Wiethe disease

Strange behaviors:

• Does not have concept of personal space
• Does have startle response, but no fear response
• Cannot recognize fear in facial expressions

Question 8

What is fear conditioning?

Example?

How does this happen within the brain?

Answer 8

Fear conditioning is the construction of implicit memories linking a situation or event to an emotional body state, particularly fear. It is a LEARNED response.

Example: Experiment with rat in cage. A tone is associated with a mild electrical shock, which causes increased blood pressure and “freezing.” Eventually the tone alone elicits the response without the shock!

Within the brain, the experience of the shock is relayed by the somatosensory system as pain. The association with the tone is learned by a strengthening of the auditory inputs through LTP. This leads to better activation of amygdala circuits by the tone.

• Important for survival responses

Question 9

What is the role of the prefrontal cortex?

Answer 9

The prefrontal cortex:

Regulates behavior/response

Modulates limbic reactivity

Involved in selecting behaviors appropriate to the context