emotion and the brain - Tom Johnstone Flashcards
define emotion
subjective experience accompanied by visceral motor and sterotypical somatic motor changes in response
- strong link with visceral motor system therefore strong assoc with preganglianic autonomic neurons in brain stem and spinal cord
define visceral motor
supplies and recieves stimulation from smooth and cardiac muscle and glands amking up the autonomic NS
define stereotypical somatic motor
supplies and recieves stimulation from skin, skeletal muscle, joints and tendons
describe cannon and bard study into emotion in cats
removed cortex, underlying white matter and basal ganglia in cats
found led to ‘sham rage’ - no obvious target but hissed, arched back, increase in bp, dilated pupils
sham rage not elicited when remove hypothallamus
findings of cannon and bard emotion in cats
cortex acts as an emotional inhibitor, regulating instinctual emotions of the thallamus - to experience the emotion not dependent on cortex but regulation of the response does
thallamus thought to be core emotional expression in the brain
problem with cannon and bard
cats have smaller cortex to humans - regulation may differ as many areas assoc with other process and complex range of emotions
what is cannons overall view of emotion
percieve stimulus - in environment which activates receptors and sends excitatory/inhibitory stimulus to cortex
LEADS TO
thallamic arousal - emotion neurons close to relay neurons in sensory pathway leading to
EMOTIONAL FEELING
AUTONOMIC RESPONSE/BODY CHANGE (ie GSR)
BEHAVIOUR CHANGE ie body language, face expression
CHANGE IN VOCAL EXPRESSION
Why are emotions useful (nico frida)
“action tendency” - prepare us for a rapid action to a stimulus
ie sad because fall so cry and this makes others empathise and help
describe Hess study into cats
electrical stimulation of hypothallamus in cats lead to rage response - bodily changes ie increased heart rate etc
hyp also link to homeostatic regulation of the body ie temp, hunger, emotion, cardiac rhythm
describe the papez loop (1937)
emotion occurs because of activity in circuit of basic structures - cortex and subcortical areas thallamus sensory cortex BG hypothallamus
what is the process of the papez loop
1- incoming sensory info relayed to thall
GOES TO
- stream of thought - thall to sensory cortex to provide awareness of environment,
- stream of movement - thall to basal ganglia involved in motor coord and planning etc
- stream of feeling - thall to hyp which regulated emotion- hyp to hipp and thall
sensory cortex, hipp and thall to cingulate cortex before feeling
describe papez stream of feeling
downstream
1- downstream (bodily response)
info from hyp to brainstem and spinal cord
lead to rapid and direct change in behaviour
decribe MaClean Truine advances of Papez loop
1- reptilian brian ‘r complex’
stereotypical rigid behaviours in brain stem and cerebellum for survival
oldest and most primitive - behaviours are ritualistic, consisten and repetitive - dont learn from mistakes as no relay to the hippocampus
describe the limbic system
group of interconnecting structures in the brain between the cortex and hypothasllamus
ie cc, cingulate gyrus (attention and reward), fornix, parahippocampal gyrus
AS WELL AS
amyg (emotion/fear reg - not in papez), hipp (memory and learning), hyp (output to viscera),
disagreement about what defines the limbic system
describe Kluver and Bucy study (1939)
remove medial temporal lovbes of rhesus monkeys
lesions affected sig amount of limbic system - including cortical areas ie amyg and hipp
kluver and bucy syndrome
visual agnosia - dont recog objects or appreciate significance
hypermetamorphosis - compulsion to approach all stimuli encountered
oral tendencies - place everything in mouth
change in emotion - tame, dull, no fear
change in sexual behaviour - hyperactive and hypersexual
describe marlowe et al 1975 kluver and bucy syndrome
human kluver bucy patient
meningoencephalitis
cant recog ibjects, flat, restless, indifferent, ingest everything see and sexual advances to males and females (pyriform cortex)
reduced social stress - less fearful of social situations
describe Le Doux fear conditioning in rats
pair tone with shock leading to freezing behaviour
lesion to medial geniculate nucleas (all auditory info through MGN of thall) - still respond to stimulus even when sever all MGN connection with auditory pathway - only connect to amyg
destroy MGN and amyg - no fear response - thereofre AMYG critical in fear learning and expression of fear
describe LeDoux ‘low road’
imprecise rough response directly to stimulus recieved in amygdala - to thall straight to amyg
generates a rapid response even though may not completely have preocessed the stimuli
Describe LeDoux ‘‘high road’
More precise and slower processing of information allowing identification of stimuli and adjusting of response
thall to cortex to amyg
LeDoux - hippocampus influence of fear conditioning
involved in context conditioning
when remove in rats, no fear when placed in cage would usually expect to recieve a stimulus even though conditioning to stimulus in in tact
describe Patient SM (Adolphs et al 1994)
bilateral amygdala destruction due to urbach luiethe disease which calcifies the amygdala and cause atrophy in anterior medial temporal lobes
cant recog fear emotion in facial expressions and rating of emotional content lower than average
little expression of fear but no problem with overall concept
describe Bechora et al 1995 patient SM study
sm fear conditioning - no fear response but did have GSR to stimuliand accurately describe relationship between stimuli and expectation of response
+ patient with selective hipp damage present fear conditioning but not procedural recall
double dissociation: amyg in fear conditioning and response but hipp in declarative learning of fear stimuli
emotional faces as stimuli in experiments
when look at facial expressions they do not immediately evoke a response - however, through evolution have learnt to associate the presentation of certain expressions with expectations of what may occur ie fear face predicts dangerous stimuli
describe johnstone et al 1995 amyg and fear faces
fmri when expose to fearful facial expressions in blocks of neutral, happy or fear
bilateral amygsala activation (greater in left) o fear faces
describe whalen et al 1998 backwards masking
fmri of amyg activation in absence of explicit expose to fearful stimuli
present stimuli for very short period that dont realise seen followed by neutral face
pps report only seeing neutral but increased activity in amyg to fear face - amyg respond rapidly to emotionally valent stimuli (HOW?)
Whalen et al 2004 - amygdala indicators of fear faces
white sclera as indicator of facial expression in LeDoux low road
masking paradigm of white sclera against black and inversed control
sig increase in amyg activation for white sclera>black sclera
problem with amygdala using white sclera as indicator of fear
widening of eye also used to indicate other emotions ie suprise
BUT
both cause increase in visual attention and indicate a change in the envionrment and that other person should adopt same emotion
Kim et al 2004 fear and suprise interpretation in amyg
fear and suprise interpreted differently dependent on the context
used ambiguous stimuli and give contextual info (positive or negative)
negative suprise face increased amygdala activation but no activation to sentence alone - amyg link to PFC which proides amyg with modulatory infor
pos increase vmPFC - assoc wih inhibition and emotional reg
what is emotional regulation
involvement of intrinsic and extrinsic processes which monitor, evaluate and modify emotional reaction sincluding intensive and temporal features to accomplish goals - any process which changes the time course, intensity or duration of an emotional response
emotional regulation processes
cognitive change ie reappraisal/reeval of situation and change of response
attentional deployment
habituation
moderation of emotion
regions involved in emotional regulation
verntromedial PFC
amygdala
dorso and ventrolateral PFC
describe morgan, romanski and ledoux 1993 study on mPFC in rats
rats have smaller PFC therefore infralimbic PFC = vmPFC in humans (thought to involve in modulation of emotional response)
lesioned mPFC in rats causing greater freezing response to CS and context stimuli in both acquisition and extinction - suggest regulates
vmPFC in extinction
auditory fear conidtioning - pair tone with shock then test after 1 day (extinction)
electrode in infralimbic cortex (vmPFC) recorded - neurons respond only in delayed (late) test of extinction not during conditioning or initial stages of extinction
response of vmPFC on day 1 correlate with success of extinction on day 2 (greater activity day 1 = greater extinction day 2) GSR
describe Milad et al 2005 vmPFC in extinction
thicker vmPFC = greater memory for extinction (less likely to have recall of fear conditioning with stimulus that is no longer percieved as dangerous)
EXTINCTION IS NOT UNLEARNING BUT INHNBITION OF RESPONSE BASED ON NEW INFO
Phelps et al 2004 amygdala activation
during acquisition of fear association - amygdala has greater response to tone shock (CS+) than tone no shock (CS-)
early extinction activity flips - greater activation to no shock pair (CS-) than shock (CS+)
late extinction - returns to before - CS+ > CS-
VmPFC also called
subgenual anterior cingulate
how is the amygdala linked to the vmPFC
strong neural fibre tract connection
inverse coupling activation in extinction of conditioned fear response
describe urry et al 2006
told pps to focus on either less intense outcome of situation (decrease), focus on intense personalised outcome of a situation (increase) or just maintain attention to the screen
amyg in regulation: response shows highest activity when increase emotional respnse and lowest when supress
vmPFC in appraisal: neg corr with amyg as vmPFC increase, amyg decrease
how is the lareral and dorsal PFC related to emotional regulation
not direct relation - not anatomically connected to amygdala but connect to vmPFC
involved in elaborative cognitive thinking and goal directed behaviour
communicate to vmPFC which regulates amygdala response
james and lange view of emotion and the brain 1880s
emotion originates from perception of physiological responses to the external environment
-immediate responde following bottom up stimuli
cannon and bard 1920s
against james and lange
james and lange wrong because
- arousal independent of emotion
emoption rapid - arousal slow
emotoins share physiological arousal tendencies
describe papez stream of feeling
upstream
2- upstream loop (feelings)
infro from hyp to cortex (and back to hyp/hippo for learning and regulation)
cingulate cortex recieves info and acts as an interface between subcortical emotional reg and cortical neurons
plays primary role in emotional experience
proects back to hyp/hipp for learning and regulation of emotional response
decribe MaClean Truine advances of Papez loop
2- paleomammalian brain
limbic system provides maternal attachment and social element
ie care for offspring, vocalise and play
plus provides memory and learning capacity
debate with as to WHAT categorises as the limbic system
decribe MaClean Truine advances of Papez loop
3- mammalian brain ‘neocortex’
higher order mammals with neocortex have complex system for symbollic thought and language
problem with mclean and truine reptilian brain
further research shows reptilian brain in layers
thought to have small cortex and large striatum - dorsoventricular ridge in reptiles thought to be analagous to mammal striatum - involve in movement in reward
DO have cortex and do not behave in purely primitive manner
evolution of brain between reptiles and humans
mcleane and truine reptilian brain
replites and mammals have common ancestor
likely that similar simpler and more primitive brain structure was once shard but both have diverged and evolved into more complex structures
problem with maclean and truine brain model
treats brain system as hierachial
deeper brain structures have greater control over cortical activity ie brain stem
structures likely to interconnect and be influenced by external factors ie context
marek et al 2013 amygdala and mPFC
maclean and truine - interconnected structures
amyg and mPFC “partners” in fear expression
amyg in acquisition and expression of fear
mPFC in learning and consolidaiton
reciprocal synaptic connections
rolls 2013
limbic system definition
single limbic system is an outdated concept and should instead be represented in teirs
ie what processing in cortex - represent stimuli but not reward value
reward value via amyg, OFC and lPFC - assoc with learning
decisions via mPFC based on value info
feedforeward netork between assoc limbic structures for integrated learning and memory
weizkrantz 1956 amydala lesion symptoms
change in tameness
lack emotional response
deficit in learning of acive avoidance following bilat amygdala removal
rolls 2015 against amygdala control of emotion
amyg damage cause deficit in face processing, decision making and autonomic conditioning
BUT changes in emotion not as severe in compariison to those produced following frontal cortex damage
RESEARCH IS NOT FULLY SUPPORTIVE
alvarez et al 2008 two process model of context condiitoning - hippocampus
context conditioning = encoding in hippocampus then intereaction with sirect stimuli encoding by the amyg
pps view contextual conditioning paradigm ie pair situation with shock
measure GSR and mri
increase to shock assoc with contezt in anterior hipp, amyg, thall, anterior insula, parahipp and parietal cortices
involved in context
sin rauch and pitman 2006
PTSD and hipp
reduced hipp vol in PTSD compared to trauma exposed and unexposed controls
+ hippocampal blood flow thought to have inadequate ectivation for necessary tasks
ji and moren
PTSD and hipp
PTSD characterised by hipp dysfunction and inappropriate contextual control of expression of acquired fear response
hipp supports context dependent retrieval of extinction memory
- PTSD may be failure to retrieve extinction memory to exposure to context causes fear > inhibition and controlled response
problems with using case studies
individualistic
- lesions specific to the patient and may span variety of areas
cant generalise and can only infer symptoms as caused by diff areas
define cog change
reeval environmental stimuli leading to a change in beh response
define attentional deployment
changing what play attention to in environment to alleviate current emotions
cartensen 1995 attentional deployment
older adults preferentially deploy attention away from neg and toward positive stimuli for goal directed regulation of emotion
define habituation
decreased response to repeatedly presetned stimuli
no longer salient
allow attention to be deployed elsewhere
how is extinction used in emotional reg studies
habituate to stimuli that is assoc with conseqences
remove the consequene
no longer aversive so no longer respond
- conditioned response to stimuli due to expected consequence not always fully extinguished and can have spontaneous recovery
morgan and ledoux 1995 extinction and emotional reg
increased fear reactivity in rats with dmPFC lesions to both conditioned and context stimuli during acquisition and extinction
d+vPFC involved in fear system but each modulated diff aspect
morgan and ledouc 1995 paradigm
1- auditory fear conditioning - tone and shcok - freezing increase day 1 then extinction
electrode in infralimbic cortex (vmPFC/dmPFC)
vmPFC in delayed extinction of tone and cs not conditioning intself or early extinction
- vmPFC for learning new assoc and inhibiting previous response
explain phelps et al 2004 results
reversal of response during early extinction unexpected
correlate with reduced conditioned response sugesting amyg actively coding the predictive value of the conditioned stimulus and altering response based on the availability of new info
quirk et al 2009 extincition
damage to infralimbic cortex in rates not impair immediate extinction but impair extinction retention
spontaneous recovery in second day
milad and quick 2002 extinction
vmPFC response to tone cs only during delated extinction
stimulation of vmPFC with tone presentation despite no extinction training reduced CR
oschner et al 2004 amyg and PFC
downreg of neg emotion = increase PFC and decrease amyg
fmri in up and down reg of neg emotion by internal (personal) or external (objective) stories
up+down = PFC and ACC
amyg up or down dependent on goal
up uniwue to rmPFC - retrieve emotional knowledge
down to right lateral/OF PFC
internal focus mPFC
external LPFC
miller and cohen 2001
emotoinal reg and cog control system
PFC top down processing of beh guided by internal states/goals
forntal lobe impairment show difficulty in STROOP
PFC guide neuronal activity dependent on task demands
