Neurobiology of Emotions Flashcards
what is an emotion?
Physiological Arousal
Anatomical Level
Hormonal Level
Expressive Behaviours
Behavioural Level
Conscious Experience
Cognitive Level
what did Darwin believe about emotions?
emotions evolved from behaviors:
(1) what an animal would do next in a given situation
(2) behaviors that are advantageous to the animal
“fight or flight” response
outline the fight or flight responce
In response to acute stress, the body’s sympathetic nervous system is activated due to the sudden release of hormones
Signalling function (we might take action) Provide strong impulse to take action Promote unique, stereotypical patterns of physiological change and behaviour
what are positive or negative emotions
Negative Emotions: moving away from what one doesn’t want
Positive Emotions: moving towards what one does want
outline folk psycholgoy belief
First comes conscious awareness, then comes physiological responses
Outline James Lange theory
William James and Carl Lange proposed an idea that was diametrically opposed to the common-sense view Physiology –> Appraisal
Stimulus (dog)
–> perceptioninterpretation of danger –> (dog)
Perception/ Interpretation (danger)
Specific pattern of automatic arousal (heart races)
–> particular emotion expressed
what is Cannon-Bards theory
Walter Cannon and Phillip Bard proposed that an emotion-triggering stimulus elicits the recognition of emotion and then body’s arousal takes place
Appraisal –> Physiology
Stimulus (dog)
Perception/ Interpretation (danger)
Emotion Experience
Specific pattern of automatic arousal (heart races)
evaluate the cannon-bard theory and the James- Lange theory
J-L: Assumes there is a unique physiological signature to each emotion
C-B: Physiological responses are generated so quickly, it’s unlikely that we could have perceived the emotion first
Outline the Schachter-Singers theory
To experience emotion one must:
(1) be physically aroused
(2) cognitively label the arousal
stimulus –> specific patterns of automatic arousal AND cogntive label e.g. “I am afraid” –> particular emotion expressed
explain Schachter-Singers classic experiment
In a 1962 experiment:
A group of 184 male participants was injected withepinephrine (hormone that produces arousal including increased heartbeat, trembling, and rapid breathing)
“a new drug to test theireyesight”
• Group A = informed the side-effects that the injection might cause • Group B = ignored side-effects
Placed in room with happy or angry confederate Participants with no explanation for arousal experienced happiness or anger
Must cognition precede emotion?
Some emotional reactions may occur without conscious thinking
Emotions involve bodily responses
Bodily responses are very noticeable (butterflies in our stomach when fear arises)
but others are more difficult to discern (neurons activated in the brain)
triangle forms between behavor, cognition, emotion arrows go both ways
what are the two dimensions of emotions
positve/negative valence
low arousal vs high arrousal
e..g positve valence but low arounsal = relaexed
low arousal and neg valence = sadness
high arousal and pos valence = joy
high arousal neg valence = fear or anger
what is the ANS
Autonomic Nervous System (ANS) controls our arousal
part of the nervous system responsible for control of the bodily functions not consciously directed: breathing, heartbeat, and digestive processes
uses epinephrine
what are the similarities and differences in emotions?
Physiological responses related to the emotions of fear, anger, love are very similar
Excitement and fear involve a similar physiological arousal
Brain responses related to the emotions are slightly different
“Different” brain areas activated by different emotions
what is a polygraph?
A lie detector
machine used in attempts to detect lies Physiological Responses: -perspiration -cardiovascular changes -breathing changes
BUT:
Control-Question Technique ANS responses to answers to innocuous questions (Is your mother’s name Betty?) are compared to those of target questions (Did you steal the money?)
50 Innocents 50 Thieves 2/3 of innocent declared guilty 1/4 of guilty declared innocent
how are emotions expressed?
Emotions are expressed on the face, by the body, and by the intonation of voice
Ekman and Friesen analyzed hundreds of films and photos of people experiencing various emotions
They concluded that there are 6 primary facial expressions of emotionsand all others are mixtures of these
Anger, fear, disgust, surprise, happiness,sadness
outline culture impacts of emotional facial expressions
Facial expressions are universal
different cultures linked the same emotions to the facial expressions
isolated New Guinea tribe members could correctly identify facial expressions
outline the brain circuits of emotion
particular brain regions are involved in emotion, but often the same areas seem to be involved in many different emotions electrical stimulation of the septum (in rodents)
how do brain lesions effect emotions
decorticate cats/dogs (without cortex) respond with unusual aggression to the slightest provocation sham rage ( à it lacks well-directed attack )
Emotional behaviors must be organized at SUBCORTICAL, with the cerebral cortex normally providing inhibitionof emotional responsiveness
what is the papez circuit
is a neural circuit for the control of emotional expression. In 1937, James Papez proposed that the circuit connecting the hypothalamus to the limbic lobe was the basis for emotional experiences.
Subcortical Circuit of Emotion “destruction of a set of interconnected pathways in the brain would impair emotional processing”
Emotional system on the medial wallof the brain linking cortexwith hypothalamus
what is the limbic system
Neocortex cingulate cortex (emotional experience) -> hippocampus -(fornix-> hypothalamus (emotional expression) –> anterior nuclei of thalamus –> cingulate cortex
outline experimental evidence ofthe limbic system
Temporal Lobe lesion in primates Kluver-Bucy Syndrome
No fear or aggression after surgery
Lesions restricted to the cerebral cortex do not produce these results à deeper regions of the temporal lobe (including sites within the limbic system) are implicated
what is the amyglada
amygdala appears to be involved in the perception of fear (as opposed to the expression of emotions)
female patient first described in 1994, who has had a complete bilateral amygdala destruction since late childhood.
She has little to no capacity to experience fear in her life “woman with no fear”
but when patients with amyglada lesion inhaed 35% CO2 triggered fear reposnces and panic attacks- more important in control of expternal fear rather than internal stimuli
outline lateralization of emotions
left hemisphere: less involved in the perception of emotion
LH lession: depressive symptoms
RH is more involved in perception of emotion, specifically facial expression and prosody
(melody of speech that conveys sincerity, sarcasm, etc.)
Presentation of emotional stimuli on the LEFT visual field à faster reaction times and accurate identification
RH lesion: Euphoria lesions
what areas are invovled in processing emotion?
several forebrain areas involved in Emotional Processing
ruly, deeply, and madly in love” Love compared with friendship involved increased activity in the insulaand anterior cingulate cortex (ACC) and subcortically in the caudate and putamen (bilaterally)
