Lecture 3 Flashcards
Neuroscience about emotion
Phenomenal experience (Feldman-Barrett) - Physiological pattern (James-Lange) and Verbal+ Non verbal expression (darwin/Ekman)
Maclean’s stage of evolution (1949, 1952)
Repitilian: Basic bodily functions
Limbic: emotions and memory (very present in other animals)
Neurocortex: higher order thinking
What are the 7 parts of the Limbic system?
- Bridge - Corpus callosum
- Cingulate gyrus: assigning emotions to stimuli –> emotion and memory
- Thalamus: relay station arousal
- Hippocampus: Memory consolidation
- Orbitofrontal cortex: higher order cognition
- Hypothalamus: arousal hormones
- Amygdala: Emotion regulation, processing biologically relevant stimuli
Is not unique in processing emotions!
Panksepp’s idea
All layers of the brain are important for emotion:
- Neocortex: planning, bomnding, appraisal, situational
- Limbic: communicative emotions
- Reptilian: emotion reflexes
What did Berridge say about Emotion processing and the difference between humans and animals?
Emotion processing is shifted opwards in humans, more to the neurocortex, whereas animals arme more in the limbic systems and reptilian areas.
Dog: food lets eat!!!
Human: food… do i like the food? i need to lose weight. eat later.
Damasio’s Somatic Marker Theory:
- Somatic markers are changes in the body and brain
- based on previous emotional outcomes of decisions
Therefore, somatic markers (either conciously or unconciously) necessary for appropiate decisions
Somatic markers are processed by OFC and the amygdala. We learn to know what’s good and what’s not good.
Somatic marker
Amygdala puts a stamp on certain emotional situations to remember them better in the future –> OFC: retrieval of marker, and the amygdala: somatic marker (also interacts with physiological areas)
Orbitofrontal cortex function
Adaptive learning based on reward and punishment. (Phinneas Gage –> impatient, obstinate, inappropriate humor, unable to settle on any of the plans he devised for future action). It was very hard for him to make simple decisions.
What are clinical characteristics of the Orbitofrontal syndrome?
- Disninhibited, impulsive behavior
- inappropiate humor, euphoria
- emotional lability
- poor judgment and insight
- distractivility
Damasio’s theory of emotions
- OFC lesions impair decision making
- impaired acquisition of somatic/bodily markers
- Emotions necessary for appropiate decisions
Where do somatical markers come from? (damasio’s theory of emotions)
A. Perception of the stimulus
B. Thoughts and evaluations about the stimulus (prefrontal cortex and the amygdala)
C. Bodily response
D. Perception of certain activity in the body (somatosensory cortex)
If you’ve encountered a situation before:
A –> B –> as if loop ! –> D
The Iowa Gambling task with skin conductance response (testing Damasio’s theory of emotions)
Pick 100 cards and maximize profit. Switch whenever you like between bad and good decks. If you always choose from the good deck, you’ll always end up with money. But the bad deck gives you more money (100 dollars) but you have more to lose. You just have to learn in time. Mensen met een amygdala lesie of OFC leasie hadden geen skin conductance dus leerde niet dat ze de good deck moesten gebruiken.
What can we conclude from the IOWA gambling task?
People with lesions to the amygdala and VM don’t learn. They know! thatb they are bad. How to choose is just really disrupted. people with healthy brains learn that they should grab from the good decks.
8 conclusions of the Damasio’s theory of Emotions
- OFC and amygdala damage increases risk taking
- OFC and amygdala damage impairs decision SCR
- OFC is about decision making and expectations
- Interaction between OFC and amygdala is crucial in somatic marker theory
- OFC lesions impair decision making and acquisition of somatic/bodily markers
- Emotions necessary for appropiate decisions
- Amygdala lesions impair lin between decisional outcome and emotion
- The acquisition of this somatic marker gives you a gut feeling!
LeDoux’s dual route theory
Two pathways for processing emotional stimuli
- High (cortical) indirect road: identifying stimulus –> emotional evaluation –> action
- Low (subcoritcal) direct road: direct evolutionary shortcut via thalamus & amygala to action
If LeDoux’s theory is true, then.. (3 predictions)
- Humans should be able to respond more quickly to emotional stimuli (threats) than to neutral stimuli
- Amygdala should be involved in recognizing threat and signal body for fast response
- We don’t need a visual cortex and still react adequatly to stimuli of threat
Humans should be able to respond more quickly to emotional stimuli (threats) than to neutral stimuli?
People have a less RT to threats, like a snike and a spider, than a mushroom.
- Amygdala should be involved in recognizing threat and signal body for fast response. True or false?
Based on study with people with Amygdala Lesions and a control group. they needed to identify T2 after seeing T1 in a short time with neutral targets and emotional targets. What can we conclude out of this?
Study to test the amygala in humans. Attentional blink: identify coloured words.
if the time after the T1 is shown is too little, T2 swill mostly not be identified when the targets are neutral.
When T2 is a very emotional target, like rape, healthy subjects were able to identify the T2. Participants with an amygdala lesion were not able to identify.
So the statements is true.
Kluver-Bucy syndrome
Bilateral surgical removal of the anterior parts of the temporal lobes, including the amygdala.
- temporal lobe epilepsy
- hypersexuality
- not taking care of off spring
- no fear repsonse to snake
- approach to threats, showing abuse to offspring
- case studies also in humans reported similar symptoms
What can we conclude of Patient S.M whom had an amygdala lesion?
SM looked freely at photos where fear was expressed on someons face. When instructed to look at eyes, S.M. could recognize fear.
He also knew how to draw faces of happy, saf, angry, suprised and disgusted faces, but didn’t know what a fearful faces looked like.
- We don’t need a visual cortex and still react adequatly to stimuli of threat. is this true?
Induced blindsight with transcranial magnetic stimulation (TMS). By using stimuli that are neutral
indicate : it shows you if we knockout the visual cortex in this prticular time window, the direct route is taking over from the visual cortex. that is why for emotional stimuli, we are still significantly better for reporting what the tagret is. The neurtal task: the amygdala oesn’t have to do the work. the direct route is not active. (direct route is always involved, but if one of them is not working, that’s why one is taking over).
So yes, this statement is true.
What can we conclude from a study based on Amygdala & Fear conditioning with a blue square and after that the get a shock? (CS and US)
Participants with an amygala lesion, so where the implicit memory was impaired, know that the blue square wil give them a shock, but simply don’t fear it. The control group fear it!
This suggests that the cortex, with its conciscious knowledge of an upcoming shock, cannot generate the physiological changes normally associated with nfear if there is no link tothe amygdala and its midbrain connections.
What does the amygdala do during conditioning?
Establishing tjhe link between CS - US covergence
Amygdala and Instructed fear. - Amygdala plays a role in implicit (fear) learning
- Phelps told particpants that blue square is paired with shock
- however, in reality participants never received a shock. Participants with amygdala lesion showed explicit learning, but never really feared it. What can we conclude?
Thus, explicit learning of emotional properties involves the hippocampus, amygdala is critical for the expression of a fear response.
