HPS111 Lecture Notes - Lecture 12: Joseph E. Ledoux, Somatic Theory, Thalamus
WEEK 12
Cognitions (thoughts, images, memories, interpretations) are involved in every aspect of emotion.
Cognitive appraisals – the interpretations and meanings that we attach to sensory stimuli. Both conscious and
unconscious processes are involved in appraisals. The idea that emotional reactions are triggered by cognitive
appraisals rather than eternal situations help account for the fact that different people can have different
emotional reactions to the same object, situation or person.
Cultural appraisals – particular situations can evoke different appraisals and emotional responses, depending
on one’s culture. E.g. Tahitians often appraise being alone as an opportunity for bad spirits to bother a person,
and fear is common emotional response. Physiological component – many parts of the body are involved in
emotional arousal, but certain brain regions, especially the autonomic nervous system and the endocrine system
play a significant role:
Emotions involve important interactions between the limbic system and cerebral cortex.
Research by psychologist Joseph LeDoux revealed that when the thalamus receives input from the senses, it can
send messages along two independent neural pathways, a ‘high road’ travelling up to the cortex and a ‘low road’
going directly to the nearby amygdala. The low road enables the amygdala to receive direct input from the
senses and generate emotional reactions before the cerebral cortex has had time to fully interpret what is causing
the reactions.
LeDoux claims that this primitive mechanism has survival value because it enables the organism to react with
great speed before the cerebral cortex responds with a more carefully processed cognitive interpretation of the
situation. E.g. a hiker sees what looks like a snake and jumps out of the way, only to realise an instant later that
it’s not really a snake but a piece of rope.
The amygdala also functions as an early-warning system for threatening social stimuli, as well as react to stimuli
that evoke strong positive emotions.
LeDoux also claims that not all emotional responses register at the level of the cortex. He suggests that people
can have two simultaneous but different emotional reactions to the same event, a conscious one occurring as a
result of cortical activity and an unconscious one triggered by the amygdala. E.g. behavioural reactions that are
at odds with the emotion they are consciously experiencing, ‘I don’t know why I came across as angry, I felt
very warm and friendly.’
Deficits in the prefrontal lobe functions causes emotions to be expressed in an unregulated manner that can have
negative consequences.
Dopamine and endorphin play a role in pleasurable emotions.
Serotonin and norepinephrine play a role in anger and fear.
Research findings (Davidson and Fox) suggest that left-hemisphere activation may underlie certain positive
emotions and right-hemisphere activation underlie negative ones. Further research showed that individuals with
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Cognitions (thoughts, images, memories, interpretations) are involved in every aspect of emotion. Cognitive appraisals the interpretations and meanings that we attach to sensory stimuli. Both conscious and unconscious processes are involved in appraisals. The idea that emotional reactions are triggered by cognitive appraisals rather than eternal situations help account for the fact that different people can have different emotional reactions to the same object, situation or person. Cultural appraisals particular situations can evoke different appraisals and emotional responses, depending on one"s culture. Tahitians often appraise being alone as an opportunity for bad spirits to bother a person, and fear is common emotional response. Physiological component many parts of the body are involved in emotional arousal, but certain brain regions, especially the autonomic nervous system and the endocrine system play a significant role: Emotions involve important interactions between the limbic system and cerebral cortex.
