14. EMOTION Flashcards
What are the two emotional consequences of withdrawal after long term opioid use?
- Increased anxiety like behaviour
- Increased depression like behaviour
What’s an emotional consequence of withdrawal after long term morphine use?
- Decreased social interaction
What are the two theories of emotion?
- James-Lange
2. Cannon-Bard
What does the James-Lange theory suggest?
- James Lange theory suggests that emotion is experienced as a result of a physiological change
- E.g feeling sad because we are crying
- Stimuli perceived -> Emotional expression -> Emotional experience (fear)
What does the Cannon-Bard theory suggest?
- The emotion can be separated from emotional experience
- No correlation between emotion & emotional expression
- Emotions are produced when signal reaches the thalamus, independent of a manifestation
What are the limitations with the three theories of emotion?
- A manifestation of the emotion doesn’t always lead to feeling of an emotion, it can be the other way around. Some individuals can’t cry because of a condition, but that doesn’t mean they aren’t sad
- It’s difficult to separate an emotion from the emotional experience/manifestation
- Older theories of emotion were based on studies of brain injury or disease. Lesion studies are not the best way to draw conclusion about neurotypical behaviour
What are two newer theories of emotion?
- Basic emotion theories
2. Dimension emotion theories
What is Broca’s limbic lobe?
- Broca’s limbic lobe refers to areas of the brain that form a ring around areas such as corpus callosum, cingulate gyrus, temporal lobe, hippocampus
- Consists of three cortical nuclei
What are the three cortical nuclei of Broca’s limbic lobe?
- Parahippocampal gyrus
- Subcallosal gyrus
- Cingulate gyrus
What is the Papez circuit?
- Papez circuit refers to structures of the limbic system which are involved in emotion such as the neocortex
- Papez circuit connects neocortex & hypothalamus
What structures comprise the Papez circuit?
- Neocortex
- Cingulate cortex
- Anterior hypothalamus
- Hippocampus
- Fornix
- Hypothalamus
What’s the role of the neocortex in the papez circuit?
Emotional colouring
What’s the role of the hippocampus in the papez circuit?
Behavioural expression of emotion
What’s the role of the cingulate cortex in the papez circuit?
Emotional experience
What’s the role of the hypothalamus in the papez circuit?
Emotional expression
What are the emotional consequences of damage to the hippocampus & anterior thalamus?
- Damage to hippocampus = hyperemotional response
- Lesions of anterior thalamus = spontaneous laughing or crying
What is the limbic system?
- The limbic system consist of many structures which are involved in behavioural & emotional responses
What are the three main structures of the limbic system?
- Cingulate gyrus
- Amygdala
- Hippocampus
**What are the functions of the cingulate gyrus?
- Role in complex motor control
- Involved in controlling mood & social interaction
- Involved in pain perception
What’s the function of the hippocampus (involving emotion)?
- Hippocampus has a key role in memory
- Involved in associating these memories with emotions & sensations
What’s the function of the amygdala?
- Learning & storing of emotion
- Particular emotions such as fear, aggression & anxiety
What are three sub-nuclei of the amygdala?
- BASOLATERAL NUCLEI
- CENTRAL NUCLEI
- CORTICOMEDIAL NUCLEI
**What’s the input of the amygdala?
- Neocortex projects to amygdala
- Basolateral amygdala receives sensory input
**What’s the output of the amygdala?
- Amygdala projects out to the hypothalamus:
- Stria terminalis & ventral amydalofugal pathway
What syndrome occurs as a result of damage to the temporal lobes?
- Damage or removal of the temporal lobe can result in Kluver Bucy syndrome
- Amygdala & hippocampus found in the temporal lobes
What are the characteristics of Kluver-Bucy syndrome?
- Reduced fear
- Reduced aggression
- Oral tendencies
- Hypersexualisation
- Reduced anxiety
- Poor visual recognition but good visual pereception
What are the consequences of an amygdalectomy?
- Removing the amygdala would produce symptoms of Kluver Bucy syndrome
- Reduced fear, aggression & anxiety
- Oral tendencies
- Flattened emotions
- As well as reduced fear, there’s also a reduced ability to recognise fear in others
What are the consequences of stimulating the amygdala?
- Increased aggression
- Increased fear
- Increased anxiety
- Increased vigilance
**What’s the role of the amygdala in learned fear?
- The amygdala is involved in the recollection of memories that can be painful or emotional
- It’s involved in associating emotions with memories so is involved in fear conditioning
Describe the projections of the amygdala to cause learned fear
- Basolateral nuclei projects to central nuclei (of the amygdala)
- Central nuclei projects to:
1. cerebral cortex
2. periaqueductal gray matter (PAQ)
3. hypothalamus
Which structure is involved in the autonomic response of fear?
Hypothalamus - autonomic response of fear
Which structure is involved in the behavioural response of fear?
PAQ - Periaqueductal gray matter - behavioral response of fear
Which structure is involved in the emotional experience of fear?
Cerebral cortex - emotional experience of fear
What are the two types of aggression?
- PREDATORY AGGRESSION
2. AFFECTIVE AGGRESSION
What is predatory aggression?
- Pure violence with no remorse
- Attacks another member
- No vocalisation, aims to kill
- No sympathetic activity
What is affective aggression?
- Aims to display dominance
- Social hierarchy
- Involves vocalisation
- High levels of sympathetic activity
Which type of aggression is the amydala more implicated in?
- Affective aggression
- Amygdala has a key role in aggression related to social hierarchy
What’s the effect of amydalectomy on aggression?
- Removing the amygdala reduces aggression
- In a dominant animal that displayed affective aggression, it become sub-ordinate & was no longer dominant if amygdala was removed
Describe the consequences of removing the cerebral hemispheres, anterior & posterior hypothalamus in cats?
- Cats who displayed sham rage had their cerebral hemispheres, anterior & posterior hypothalamus removed
- Removing cerebral hemispheres -> sham rage remained
- Removing cerebral hemispheres + anterior hypothalamus -> sham rage remained
- Removing cerebral hemispheres + anterior hypothalamus + posterior hypothalamus -> no sham rage
- Posterior hypothalamus has a role in sham rage
Which structure was found to be involved in sham rage in cats?
- Posterior hypothalamus
What’s the consequence of stimulating the hypothalamus?
- Electrically stimulating the hypothalamus can lead to predatory or affective aggression
What type of aggression does the lateral hypothalamus cause?
- Predatory aggression
- Lateral hypothalamus
What type of aggression does the medial hypothalamus cause?
- Affective aggression
What are the two hypothalamic pathways involved in aggression (autonomic function)?
- MEDIAL FOREBRAIN BUNDLE ->VTA
2. DORSAL LONGITUDINAL FASCICULUS -> PAQ
Which hypothalamic pathway produces affective aggression?
- Dorsal longitudinal fasciculus
- Projects to PAQ (periaqueductal gray matter) to cause AFFECTIVE aggression
Which hypothalamic pathway produces predatory aggression?
- Medial forebrain bundle
- Projects to VTA to cause PREDATORY aggression
What’s the link between serotonin & aggression?
- Serotonin & aggression are inversely related
- High serotonin = reduced aggression
- Low serotonin = reduced aggression
What’s the effect of a 5HT antagonist on aggression?
- 5HT antagonist = increased aggression
- Blocks serotonin receptor
What’s the effect of a 5HT agonist?
- 5HT1A & 5HT1B agonist = reduced aggression & reduced anxiety
