emotion

define emotions

automatic response programs generated by the limbic system, based on sensory or other input, causing bodily sensations

four behavioral components of emotion

feelings (subjective experience; cortex), action, physiological arousal (bodily responses; ANS), & motivation

explain the evolutionary goal of emotions

primarily physiological responses to threat or opportunity, to push us away from danger and toward reward

facial expression link to emotion

signal a person's state of mind or intention

someone’s facial expression effect on self

amygdala reacts by mirroring the emotion via mirror neurons: the basis of empathy

voluntary smile vs emotional smile

• voluntary via motor cortex and cranial nerves

• emotional via limbic system (medial forebrain) (motor areas in

  anterior cingulate cortex) — orbicularis oculi activate only in a genuine emotional smile

difference between voluntary & emotional smile

two anatomically and functionally distinct descending projection systems to the facial muscles

amygdala function

fear responses, emotional processing, links cortical and subcortical regions

hypothalamus function

triggers physiological responses (heart rate, hormones, etc.)

thalamus (mediodorsal) function

sensory relay, sends signals to both cortex and amygdala

orbital & medial prefrontal cortex function

conscious emotional experience, regulation

ventral striatum (ventral basal ganglia) function

motivation, reward

hippocampus function

stores contextual information that can confirm or modify emotional responses

conscious route emotional processing

sensory input → thalamus → sensory cortex → conscious awareness → more thoughtful response

unconscious route emotional processing

sensory input → thalamus → amygdala → hypothalamus → immediate physiological response

differences conscious & unconscious route

• conscious - informed by hippocampal memory, slow but more accurate

• unconscious - fast, occurs before awareness

• both run simultaneously

amygdala activity in depression

hyperactive left amygdala activity when interpreting emotions in faces, especially fearful one → normalizes with antidepressants or behavioral therapy.

amygdala activity in psychopathy

bilateral volume reductions in the amygdala + decreased amygdala and orbitofrontal cortex responses to emotionally provocative stimuli

concept of lateralization of emotional functions

left and right hemispheres play different roles in emotion, both play roles!

right hemisphere role in emotional functions

• dominant for emotional aspects of language (prosody: tone, emotional coloring of speech)

• detecting emotional nuances in speech and more accurately identifies emotions in facial expressions presented to the left visual field

left hemisphere role in emotional functions

left facial musculature more fully expresses emotions