What kinds of responses are emotions made up of?
- Physiological responses – Changes in heart rate, increased perspiration and respiration.
- Overt behaviors – Facial expressions, vocal tone and posture.
- Conscious feelings – Subjective experiences of sadness, happiness, and so on.
What happens during the fight or flight response?
In a frightful situation, the autonomic nervous system (ANS) releases
stress hormones (adrenaline) and glucocorticoids (cortisol), which “control the Fight-or-
Flight response”.
Increase in: Respiration, heart-rate, blood pressure, blood glucose, stress hormones
Energy flow to: Large muscle groups, pain suppression, reflexes, perception/awareness
Energy taken from: Digestion, reproduction, immune system, touch receptors
What is the James-Lange theory of emotion?
- James-Lange theory of emotion – Conscious feelings of emotion depends on what our body is telling us “We are afraid because we run”.
What is the modern emotional theory?
- Emotional stimuli give rise to bodily responses, which, interpreted in certain context, give rise to conscious feelings of emotion.
How do emotions influence storage and retrieval of memories?
Encoding
- experiment w/ story: traumatic story was remembered better
Retrieval
- experiment w/ recall of autobiographical memory: participant could remember things better if they were congruent with their mood (emotion as a memory cue)
- Flashbulb memories
- features are very vivid but incomplete and can contain inaccurate details
What types of learning of emotional responses are there?
- Conditioned Emotional Responses: fast, long-lasting and hard to extinguish
- Conditioned Avoidance: example of instrumental conditioning
- Learned Helplessness
How did the experiment which showed prediction of danger in rats look like?
Before pairing with a US, a tone CS evokes a mild increase in blood pressure (a) and a brief period of freezing (b). This is an unlearned startle response. After, the tone CS is paired with a foot-shock US. After pairing, the tone CS evokes a strong increase in blood pressure (a) and extended freezing (b). These are conditioned emotional responses, indicating that the rat has learned CS-US association.
How did the experiment which showed rat’s learning of avoiding danger look like?
-> Rats are shocked when going into dark section
X Rat remembers earlier unpleasant experience -> freeze as soon as it is placed in experimental apparatus -> CR to experimental context.
X Rat delays before it crosses into dark area and will not spend much time there (avoidance) -> Instrumental conditioning.
- Instrumental conditioning – Stimulus S (= apparatus) -> Response R (= entering dark area) -> Consequence C (= getting shock).
What brain systems have special roles in emotional learning and in interpreting the context and monitoring display of emotions?
Emotional learning: Structures of limbic system (incl. thalamus, cingulate cortex, hypothamalus, amygdala)
Interpreting: Frontal cortex
What is the amygdala important for? Name the three nuclei! (there are 10)
- learned emotional responses
- emotional modulation of memory storage and retrieval
Lateral nucleus
– Primary entry point for sensory information into amygdala – This information comes from thalamus (= sensory gateway to brain) and cortex.
Central nucleus
Projects out of amygdala to:
a. ANS – Driving expression of physiological responses (arousal, release of stress hormones).
b. Motor centers – Driving expression of behavioral responses (freezing, startle).
Basolateral nucleus
– Projects to cortex, basal ganglia and hippocampus (memory storage areas). It also provides pathway by which emotion modulates memory storage and retrieval in those structures.
What can be seen in patients with bilateral amygdala damage?
Disrupted ability to learn and display new emotional responses
- Experiment of skin conductance response: Patient with bilateral amygdala damage responds to US, but cannot learn emotional response to CS.
- > Amygdala lesions damage central nucleus, disrupting ability to express learned fear response, because the damage disrupts major output pathway to ANS and motor centers, that drive freezing response.
What two pathways are there concerning the amygdala and emotional learning?
Direct pathway – Faster (12ms) but conveys less detail -> Fast and rough. (thalamus -> amygdala)
Indirect pathway – Slower (19ms) but involvement of cortex allows finer discrimination of stimulus details -> Slow but accurate. (thalamus -> cortex -> amygdala)
What can be seen in the lateral nucleus of rats in learning?
X Experiment with rats and odor – Rats were presented with various odors (almond and anise) and trained so that one odor (almond) preceded tail-shock US. Rats quickly learned to freeze in anticipation of shock whenever there was almond odor. To anise odor, they showed no fear response.
->After training, neurons in lateral amygdala responded strongly to almond odor paired with US.
Stimulation of amygdala causes dramatic fear response in some animals, but only mild feelings in humans. But why?
Modern emotional theory – Our conscious emotional feelings depend not only on our biological responses, but also on how we interpret the situation.
How might amygdala activation affect memory?
Outputs from central nucleus travel to ANS and cause adrenal glands to release stress hormone epinephrine – Helps mediate components of FOF response.
X Epinephrine cannot affect brain directly ->Blood-brain barrier – Membrane that controls passage of substances from blood into CNS.
- Epinephrine cannot cross this barrier, but it can activate brainstem nuclei that produce chemically related norepinephrine, and project it to basolateral amygdala (BLA). From there, outputs travel to brain regions including hippocampus and cortex.
Neurons in BLA fire in rhythmic waves and project to cortex, hippocampal region and other memory sites. Rhythmic activation of many neurons facilitates LTP between coactive neurons. Therefore, BLA may facilitate learning in cortex and hippocampal region.
What role does the hippocampus have concerning emotion& memory? (+Experiment)
region critical for new episodic memory formation, but it is not limited to learning about facts/events: it also plays role in nondeclarative memory.
Healthy humans report contextual information about conditioning experiment. Patients with HL cannot report this information – but patient with AL can.
->This suggests a dissociation between conditioned emotional responding (amygdala) and contextual or episodic learning (hippocampus).
What role do the frontal lobes have concerning emotion
Involved in social behavior, which demands ability to express emotion and read it in others.
What theories are there concerning phobias?
- Classical conditioning
2. Alternative theory: biologically predisposed fear
What treatment methods are there for Phobias?
- Systematic desensitization – Therapy for phobias where successive approximation of CS are presented, while patient learns to stay relaxed. Eventually, even the CS itself does not elicit a fear response, because the steps are taken very gradually Slow and painstaking process, but successful and long-lasting.
- Propranolol – And other drugs, block/interfere with epinephrine and can also help individuals who suffer from phobias. Because it is critical for FOF response to happen, blocking it suppresses body’s response to fear-producing stimuli Predicted by James-Lange theory of emotions.
How do brains of PTSD patients differ from normal brains?
Smaller hippocampal volumes
Why might PTSD occur?
Classical conditioning
