Brain And Emotion Flashcards Preview

psychology > Brain And Emotion > Flashcards

Flashcards in Brain And Emotion Deck (27):
1

Brian systems

Prefrontal cortex (hemispheric differences)
- Dorsolateral, ventromedial, orbirofrontal

Subcortical structures
- Limbic system, nucleus accumbens, amygdala

Posterior RH
- Perception of expressions

2

PFC: Emotion memory and recall

Phobics given pictures of aversive stimuli

Results in PFC activation; seems to be location of recall of emotion memories

Emotions are essential for motivation and planning. Need an emotional memory and the PFC seems to be the location of emotional working memory

3

PFC Hemispheric differences

Davidson emotional films
- Left anterior activated during positive affect - right anterior during negative affect

Sutton et al (1997): Pictures: induced changes in mood

PET scan. Right side increase during negative affect

Left side increase during positive affect and left nucleus accumbens

'Socially wary' children more right prefrontal activation (Davidson 2001)

4

Amygdala - Substantial evidence has an important role in the:

Perception of fear

Feelings of fear

Learning to recognise fear and aversive events (associative aversive learning)

5

Breiter et al (1996)

The amygdala is activated by perception of fear in the face of another

6

Morris et al (1996)

Activation in the lef amygdala showed a linear relationship with decreasing intensity of happiness and increasing intensity of fear

7

Amygala

Stimulating amygdala in animals produces freezing and fear response

Stimulation and seizures focused on the human amygdala frequently produce fear or other emotional responses (Gloor, 1990)

8

Kluver and Bucy (1937)

Lesion to medial temporal lobe:
Animals placid - lacking emotion

Will approach fear inducing stimuli with no display of anger or fear

Inappropriate sexual behaviour: mounting inanimate objects

Weiskrantz (1956) demonstrated that it was the amygdala within the medial temporal lobe

9

Klüver-Bucy syndrome

Lesions of amygdala and surround

emotional blunting: displays a flat affect and may not respond appropriately to stimuli

Hyperphagia: extreme weight gain, oral stimulation or exploration and not feeling hungry

Inappropriate sexual behaviour: may be an increase in their sexual activity

Visual agnosia: an inability to visually recognise objects

10

Urbach-Wiethe Syndrome

Rare

11

SM

progressive calcification of the amygdala. A few early memories of fear but no fear in adulthood

Is emotional - has other emotions

Personal space .34 metres (Kennedy, 2009)

Amygdala helps create personal space

Is fascinated by sights that terrify others eg haunted house

Exotic pets (spiders, snakes)

12

Recent SM findings

Tsuchiya et al (2009)
briefly presented fear expressions or fear scenes

Button response - choose which was most fearful. normal response

unlimited time - abnormal response

Kennedy and Adolphs (2011) gaze to eyes improved performance

13

Interpretation

Initial subconscious detection occurs in other regions and is accurate

Then amygdala directed to gather further evidence eg form eyes to assess the danger

non conscious processes may cause arousal but lack of amygdala prevents correct interpretation

14

Amygdala and individual differences

- Big individual differences in quality and intensity of amygdala response (blood flow, glucose use) to same stimuli

- Depressed patients with more severe depression had greater blood flow in amygdala (Drevets, 1995)

- Higher dispositional negative affect - higher glucose metabolism

15

Amygdala questions

Affect in general, negative affect in particular or fear most specifically? (Davidson and Irwin, 1999)

Where is happiness?

Left, Right or both sides equally involved in fear

16

Adolphs et al 1999

Emotion recognition in nine amygdala patients found that deficits apparent for all the negative emotions

Amygdala deficits may be more general - affecting all the basic negative emotions

17

Issues

Fear perception hardest
Controls find fear more difficult to recognise than other emotions
Just a product of any generalised brain damage

18

Adolphs, Tranel and Damasio, 2002

Patient B - bilateral lesions in the insular vortices damage may account for impairments in recognising disgust

Seems unable to feel disgust: ingests items indiscriminately including inedible items. Shows no disgust to food related stimuli (such as pictures of food covered with cockroaches)

19

Phillips et al (1997)

Two levels of disgust and fear expressions were used
- morphed images containing 75% of the expression and 25% of neutral and 150% caricatures of the expressions
- The baseline condition contained morphs composed of 25% happiness and 75% neutral


Right insula activated in response to expressions of disgust

20

Winston et al 2002

Trust (in addition to disgust) in the insula

Right insula and amygdala activated for untrustworthy faces

Amygdala and the right insula are activated by untrustworthy faces

The insula is activated in a wide variety of functional imaging studies of emotion

One possible role for the insula is as the basis of 'gut feelings' about emotive stimuli. Untrustworthy people cause a gut reaction?

21

Interim Summary

The amygdala has a large role in processing the emotion of fear (but task difficulty) - Rapcsak et al (2000)

might also process a wide range on negative emotions (and trust)

There's disgust and trust in my insula and trust fear etc in amygdala

New evidence suggest there are other faster fear pathways that are not involving the amygdala

22

high and low road (Le Doux, 1994; 1999)

2 routes to an emotional response

1. Fast and crude fear response (low road)
2. Slower and more sure (high road)

Low road: thalamic-amygdala route very quick effective and very basic analysis of stimuli. very fast emotional (fear) response

23

High and low road

No need for cognitive appraisal for an emotion to occur

Low road perfect for fast defence mechanism

24

LeDoux

Intact 'High road' is necessary for learning a ear association

Once it is learned the high road is not required for a fear response

Makes many emotions unconscious and difficult to extinguish (eg anxiety and phobias)

25

Summary

Many brain regions involved in emotions and d

26

Summary

Many brain regions involved in emotions depends on aspect (perception/experience) of emotion

PFC - negative and positive. Approach - withdrawal. Emotional memories, emotion regulation, coordination prediction

Amygdala - Fear and negative emotions

Insula - disgust and trust

27

What is an emotion?

Emotional is a state of feeling and experiencing

It has several dimensions including behavioural, physiological and cognitive