Lecture Fred Boy – Brain and behaviour
Continued… (Lectures all in one)
Historical perspectives – not too important to exam
Cannon-Bard: emotions only occur in the brain and the bodily response are the consequences of the brain,
emotion happens first.
Papez and Maclean: best theory, now dominating, most modern accepted. Brought cortex into emotional
processing, the cortex is now part of the emotional experience. Nuclei below cortex believed to do only
very basic processes but found that the cortex plays large role in emotion.
Six emotions: first described by Ekman. Common to all humans. Need emotions to communicate,
component of survival. Phenotype of emotions – mouth opening, eyes, muscles, pattern of muscle
activation on the face reflects pattern of brain activation.
Non basic emotions: can have mixed emotions, Ekman did not take into account mixed emotions. Basic
emotions found in non-human animals but don't find more complex emotions of emotional blends/mixed
emotions, however they may exist but we do not have the technology and resources to measure these.
Cognitive approach: Don't need to know for exam? To express emotions, needs to describe it with
language, an element of cognition. Ortony, emotions are how we react to event we are concerned by,
action. Always appraise emotions, sometimes emotions suppressed, most therapies are based on
appraisal, reappraisal, suppression.
Specialised hardware:
Amygdala: primal part of brain, low level, share with many animals e.g. Snakes, lizards. Common in a group
of primates to have a social structure, hierarchy, very fixed until member dies, leaves. Before lesion, was
stable. After lesions to Amygdala, social structure was changed. If social structure is based on aggression,
removed Amygdala and group works change.
Amygdala and fear conditioning: basic conditioning paradigm. Over time, measured freezing – time the rats
are frozen in behaviour, fear response. When shock removed, freeze response still high just at the sound
but will extinguish slowly. (Control). Those with unilateral Amygdala biopsy, lower and bilateral even lower,
do not condition, don't learn to fear tone, extinction quicker in unilateral. Amygdala important for fear
conditioning. Importance of two amygdalae. Necessary to learn fear. Important: lesions don't disrupt fear
response to the shock!
Fear conditioning in humans: Amygdala processes fear at the individual level but also processes fear in a
social environment. Patients with lesions don't learn fear response, skin conductance response doesn't
occur following fearful stimulus. Amnesiacs will not remember the conditioning and association but will
show a response in skin conductance. Amygdala necessary for emotion identification of fear, can still
identify other emotions but not fear, will also disrupt identification of fear in voice as well as in the face.
Once fear learnt, Amygdala no long activated, only activated during learning of fear.
EXAM QUESTION: role of Amygdala in fear processing?
Fear, beyond Amygdala: not only thing responsible for learning fear. Need to see or hear the fearful
stimulus, requires visual cortex, visual thalamus needs to recognise stimulus and visual cortex processes
visual information which the returns to the Amygdala. Fear involved in survival and so a faster reaction
, maybe be required. There is a fast and a slow route, fast route doesn't require visual cortex to process
stimulus information to elicit reaction. Slow route also uses OFC to process evaluations.
Lecture Continued…
Amygdala: beyond fear: Amygdala involved in reward response, rats were given either a pleasant or
unpleasant odour , Amygdala more activated with unpleasant. Amygdala is involved in processing fear and
reward. Also involved in indexing intensity of emotional stimuli. Activity in Amygdala is correlated with how
pleasant or reward full a stimulus is. Happy faces generate bigger response in Amygdala than sadder faces,
for extraverts. Interaction between personality and emotional stimuli.
Summary: shows how we like something, how intense we are feeling about a stimulus.
The insula: small love folded behind the frontal cortex, first part of the cortex that evolved. Viewed as an
independent part of the brain.
Insula and recognition of disgust:
Beyond disgust: perceiving how you feel about the body, monitor perceptions of body responses.
Basic emotions summary:
Motivation
Maslow’s hierarchy: do not need to learn
Individual differences in emotional history, not reflexive animals.
OFC: above eye.
And current reward values: PET definition, describe. Radioactive glucose or oxygen to participant, positrons
emitted and detected. Initially all wanted the chocolate,and for all it was pleasant. Ratings declined with
consumption of pieces increasing, activity in OFC also reduced with ratings.OFC is specialised part of the
brain that evaluating the value of something, how much we want something. Wine tasting: given wine,
told it was different prices, after each trial had to rate liking of wine, cheaper wine had initial activation but
diminished rapidly, expensive wine causes brain activity of OFC to increase greater than cheap wine,
remain high for longer period of time, declines slower. Wine was the same, just told different prices. OFC
processes the value of things. Music: listen to music they like and don't like, rated subjective experience
(likeness rating), activity in the ventral medial Prefrontal cortex (Google) greater and in VC, VMPF –
another name for OFC???
Phineas Gage: unable to regulate emotions, became impulsive, violent, aggressive, alcoholic, ethical
behaviour changed.
Brain and behaviour, Fred Boy.
Continued…
Anterior cingulate cortex: …
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