Emotion

Question 1

Significance of Emotions

Answer 1

Basis of studying behavioural manifestations (animal models, brain lesions and human brain imaging techniques). Emotional experience leads to emotional expression.

Question 2

Affective neuroscience

Answer 2

neural basis of emotion and mood

Question 3

James-Lange Theory of emotion

Answer 3

Emotion is result of a response to physical changes in the body

Question 4

Cannon-Bard Theory of emotion

Answer 4

Emotions independent of emotional expression

Question 5

Contrasting+complimenting views of (J-L) vs (C-B) theories

Answer 5

Stimulus percieved leads either to emotional experience (fear, for example) shapes emotional expression (C-B). Opposing this is a visceral response from perceived stimulus leading to an emotional experience.

Question 6

Unconscious emotions

Answer 6

Stimulus can have an emotional impact without conscious awareness. For example: aversive conditioning to masked stimulus results in increased skin conductance–resulting in increased activity in the amygdala

Question 7

Broca’s limbic lobe

Answer 7

Cortex forming a ring around corpus callosum: Cingulate gyrus, medial surface temporal lobe, hippocampus.

Question 8

Papez Circuit (limbic system) loop

Answer 8

Limbic structures, including cortex, are involved in emotion.
Emotional system on the medial wall of the brain linking cortex with hypothalamus.

(1)NeoCortex(2)Cingulate cortex (emotional experience)—> (3) Hippocampus—(fomix)–> (4) Hypothalamus (emotional expression)—–>(5) Anterior nuclei of thalamus—–> (2)C-C

Question 9

Papez circuit basis

Answer 9

Cortex: emotional experience

Hippocampus: Behavioural expression of emotion

Rabies infection implies that hippocampus is involved in emotion (hyperemotional response)

Anterior Thalamus: lesions lead to spontaneous laughing+crying

Question 10

Limbic system (who popularized and what the evolution means)

Answer 10

Maclean popularized the term.

Evolution of limbic system allows animals to experience emotions beyond stereotyped brain stem behaviours (reptilian brain behaviours)

Question 11

Single emotion system concept (difficulties)

Answer 11

• Diverse emotions
• Many structures involved in emotion

-No one-to-one relationship between structure and function
Limbic system: Utility of single, discrete emotion system questionable

Question 12

Klüver-Bucy Syndrome

Answer 12

Temporal lobectomy in rhesus monkeys:

• Decreased fear and aggression
• Decreased vocalizations and facial expressions

Temporal lobectomy in humans
Exhibit symptoms of Klüver-Bucy syndrome:
-Flattened emotions
-Probably related to destruction of the amygdala

Question 13

Amygdala and Fear

Answer 13

Bilateral amygdalectomy reduces fear and aggression in all animals tested:

-Anger, sadness, and disgust may also be affected

Question 14

S.M. case study

Answer 14

Inability to recognize fear in facial expressions
Electrical stimulation of amygdala -> Increased vigilance or attention
Fearful faces produce greater amygdala activity than happy/neutral faces

Question 15

Is involved in forming memories of emotional events

Answer 15

Amygdala (confirmed by fMRI and PET imaging)

Question 16

Amygdala and Aggression (2 types)

Answer 16

1. Predatory aggression-Attacks

2. Affective aggression-for show

Question 17

(Potential) Goal of amygdalectomy and psychosurgeries

Answer 17

reduced human aggression:

• Reduced aggressive asocial behavior
• Increased ability to concentrate
• Decreased hyperactivity

Question 18

Hypothalamus and it’s involvement in Aggression

Answer 18

Removal of cerebral hemispheres but not hypothalamus -> sham rage

• Behaviour reversed with small lesions in hypothalamus
• Hypothalamus may normally be inhibited by telencephalon.

Question 19

Hypothalamus and aggression (Flynn, 1960)

Answer 19

• Elicited affective aggression by stimulation medial hypothalamus
• Predatory aggression elicited by stimulating lateral hypothalamus

Question 20

Midbrain and Aggression

Answer 20

Two hypothalamic pathways to brain stem involving autonomic function:

(1)Predatory aggression:
Medial forebrain 
bundle -> ventral tegmental area
(2)Affective aggression Dorsal longitudinal 
fasciculus -> periaqueductal grey

Question 21

Serotonin and aggression

Answer 21

Serotonergic raphe neurons project to the hypothalamus and limbic structures via the medial forebrain bundle:

↓Serotonin turn-over
↑aggression in rodents
Drug PCPA blocks serotonin synthesis ↑aggression

Question 22

Serotonin Receptor Knockout Mice

Answer 22

14 serotonin receptor subtypes 
Knockout Mice (recombinant DNA techniques)

5-HT1A and 5-HT1B
5-HT1A and 5-HT1B; autoreceptors—global regulatory role

5-HT1B High concentrations in raphe nuclei, amygdala, PAG, basal ganglia

Agonists: Decrease anxiety, aggressiveness

Question 23

Neural pathway overview of emotions

Answer 23

Experience, expression of emotion involves widespread activity in the nervous system from cortex to ANS as well as: limbic structures, hypothalamus, amygdala