Thalamus and Hypothalamus Flashcards
Define emotion.
An automatic physiological, behavioural and cognitive reaction to an external or internal event.
Define emotional experience.
A subjective feeling.
Define emotional expression.
A covert or overt behaviour.
Define basic emotions.
A subset of discrete emotions thought to be universal across cultures.
Describe the James-Lange theory of emotion.
Sensory stimuli that compose certain sensory events directly result in bodily changes, and emotions are the brain’s interpretations of these changes.
Describe the Cannon-Bard theory of emotion.
Physiological arousal and emotional experience can occur at the same time but are independent of each other.
Describe the two main arguments against the James-Lange theory of emotion.
The same patterns of physiological responses can be caused by a variety of stimuli, so how does the brain determine what emotion should be felt?
If we had to experience a physiological response to experience emotion then what of people who are completely paralysed and unable to sense these bodily changes but still experience the full range of emotion?
Describe Schachter and Singer’s two-factor theory of emotion.
Sensory events directly trigger a physiological response but our emotions are differentiated based on the cognitive label (consistent with the situation or context) we apply to those physiological reactions.
Describe the discrete theories of emotion.
Emotions can be distinguished from one another and are represented by specific response patterns in different areas of the brain.
Describe the dimensional theories of emotion.
Emotions can be broken down into basic elements and it is the individual differences that result in the different ways people experience emotions.
Describe the theory of constructed emotions.
Emotions are not hardwired but emerge into consciousness through perception of physiological responses to the situation and how each individual then categories these responses.
What is the function of the hypothalamus?
Regulate the ANS and the physiological changes that accompany emotional states.
Regulate the endocrine system through control of the pituitary gland.
What is the function of the hippocampus?
Learning and memory.
Recognition of novelty.
Recollection of spatial relationships.
What is the function of the parahippocampal gyrus?
Works in conjunction with other structures to help modify the expression of emotions.
What is the function of the amygdala?
Influences our behaviour and activities to meet our internal needs, e.g. feeding, sexual interest and emotional reactions.
Why do smells evoke such strong memories and emotions?
It is directly connected with the limbic system.
What is the function of the cingulate gyrus?
Modifies behaviour and emotion.
What is the fornix?
A pathway of nerve fibres that transmit information from the hippocampus and other limbic areas to the mamillary bodies.
What is the function of the mamillary bodies?
Acts as a relay station, transmitting information to and from the fornix and thalamus.
How does the hypothalamus communicate with the hippocampus and septum?
Via the fornix.
How does the hypothalamus communicate with the amygdala?
Via the stria terminalis and amygdalofugal fibres.
How does the hypothalamus communicate with the frontobasal parts of the olfactory brain?
Via the medial forebrain bundle.
How does the limbic system communicate with the neocortex?
Via the frontal and temporal regions.
What is unique about the frontal brain as a neocortical region?
It is the only neocortical region with direct neuronal connections to the hypothalamus.
What is the role of the temporal brain?
Mediates information from the visual, auditory and somatosensory cortices to the amygdala and hippocampus.
An fMRI and PET study showed that there were specific patterns of neural activity associated with which five basic emotions?
Happiness.
Sadness.
Anger.
Fear.
Disgust.
Happiness is associated mainly with activity in where?
Right superior temporal gyrus.
Sadness is associated mainly with activity in where?
Left medial frontal gyrus.
Anger is associated mainly with activity in where?
Left inferior frontal gyrus.
Fear is associated mainly with activity in where?
Left amygdala.
Disgust is associated mainly with activity in where?
Right insula.
Inferior frontal gyrus.
What suggests that emotions are dependent on functional networks consisting of several areas?
Several of the same brain areas are activated for more than one emotion.
What gives rise to Kluver-Bacy syndrome?
Bilateral lesion or damage to the amygdala.
What are the symptoms of Kluver-Bacy syndrome?
Inability to recognise or identify objects by sight (visual agnosia), by touch (tactile agnosia) or by sound (auditory agnosia).
Intense desire to explore the immediate environment (hypermetamorphosis).
Hypersexuality.
Flattened emotions.
Name the four nuclei of the amygdala.
Lateral nucleus.
Accessory basal nucleus.
Central nucleus.
Basolateral nucleus.
Describe what happens in the brain when we experience an aversive stimulus.
Sensory information is projected to the thalamus.
It is relayed to the lateral nucleus.
It projects directly to the central nucleus and indirectly via the basolateral nucleus and the accessory basal nucleus.
How does activation of the central nucleus result in the release of cortisol?
Via the connections with the central gray, lateral hypothalamus and basal nuclei of the stria terminalis.
What is the function of the direct pathway from the thalamus to the amygdala?
Allows a rapid, reflexive response to the potential threat.
Adaptive with experience but acts too quickly to allow further analysis of the situation.
How does the indirect pathway from the thalamus to the amygdala via the sensory cortex work?
Information is analysed by the sensory cortex and hippocampus, and the outcome is relayed moments later to the amygdala. If there is a real danger, the amygdala response is accentuated.
What the proposed function of the hippocampal involvement in the indirect pathway from the thalamus to the amygdala via the sensory cortex?
It is thought to add a further element to processing of information by checking memories of past experience.
What causes Urban-Wiethe disease?
Calcium build-up in the brain causes degeneration of the temporal lobes.
What are the symptoms of Urban-Wiethe disease?
No fear response when exposed to fearful stimuli.
Unable to recognise emotional facial expressions, especially those expressing fear.
Describe the somatic-marker hypothesis.
The physiological responses that arise through activation of the ANS, and the emotional events that they are associated with are thought to be stored as somatic markers within the ventromedial prefrontal cortex.
What is thought to be the function of somatic markers?
To act as an implicit biasing signal that plays a role in decision making.
What is the involvement of the cerebellum in emotion?
Plays a key role in the storage of both positive and negative memories of emotional events.
The vermis is activated during recall of what?
Emotional personal life experiences.
