Topic 12: Emotion Flashcards
What is affective neuroscience?
studies the neural mechanisms underlying emotion
emotional contexts can modulate many cognitive processes, making it a relevant influence on a huge range of things (memory, cognitive control, decision making, social behavior)
the study of affective neuroscience also has some pretty clear potential practical/applied benefits
What is the relationship between the amygdala and fear-based responses?
the amygdala is located in the medial temporal lobe (MTL), close to ventral anterior IT cortex
not typically considered part of the visual system, though it may play a particularly important role in responding to information in that modality
associated with the organization of various emotional responses (with much work aimed at understanding it’s role in fear-based responses)
What was the study by Adolphs, Tranel, and Damasio (1998) on judging trustworthiness?
studied three patients with bilateral amygdala lesions making judgments about the trustworthiness of various faces
the face stimuli had been independently rated on the dimension of trustworthiness by healthy controls
the faces judged to be least trustworthy by controls were not judged to be any less trustworthy by these patients
What was the methodology of the study by Engell, Haxby, and Todorov (2007) on judging trustworthiness?
applied a similar procedure as used by Adolphs, Tranel, and Damasio (1998) to an fMRI study
intially told participants the experiment was about memory for faces, then scanned them while they were viewing the face stimuli
then measured their behavior correlates (trustworthiness judgments) in a seperate session
What were the findings of the study by Engell, Haxby, and Todorov (2007) on judging trustworthiness?
the correlation is stronger between the amygdala activity of an individual and the group average ratings of trustworthiness for that associated face, as compared to the amygdala activity of an individual and their own average ratings of trustworthiness for that associated face
What was the interpretation of the study by Engell, Haxby, and Todorov (2007) on judging trustworthiness?
the result of the study was interpreted as reflecting two sources of variance:
a relatively automatic and consistent contribution from the amygdala
a more controlled and variable contribution from higher-level areas (e.g. the frontal cortex)
What does the source of variance of a relatively automatic and consistent contribution from the amygdala tell us about trustworthiness judgments?
if our judgments about the trustworthiness of faces is influenced by amygdala activation, the group average related to this signal should capture some of the variance in these judgments
What does the source of variance of a more controlled and variable contribution from higher-level areas (e.g., the frontal cortex) tell us about trustworthiness judgments?
however, adding more complexity (and variability) to that “base” signal, factors like personal history then become relevant at the individual level (e.g. you grew up with someone who looks similar to one of the faces you’re judging), which will have little to no relationship with amygdala activation
What is the study by Vuilleumier et al. (2004) on imaging clinical populations with amygdala damage?
showed that patients with amygdala damage have the same typical response to faces, as compared to houses, as healthy controls
however, they do not show a difference in their response to fearful (as compared to neutral) faces
seems to support the interpretation provided by Adolphs, Tranel, and Damasio (1998)
What are the ethical concerns with judging trustworthiness?
how do we make “trustworthiness” judgments based on faces?
would we expect biases to creep into the equation? if so, how should this be handled?
for example, should we incorporate those biases into models that try to predict how people judge trustworthiness based on appearance?
if so, is there a risk that AI will further perpetuate those biases?
What was the goal of the study by Cahill, Prins, Weber, & McGaugh (1994)?
administered the beta-adrenergic antagonist porpranolol and manipulated the emotional tone of a narrative presented (emotionally arousing or neutral), then tested their memory
among other things, adrenergic receptors are sensitive to norepinephrine and epinephrine
What were the four experimental groups in the study by Cahill, Prins, Weber, & McGaugh (1994)?
two groups received propranolol: of those, one saw the emotional story and the other the neutral story
two groups received a placebo: again, one emotional and one neutral
What were the results of the study by Cahill, Prins, Weber, & McGaugh (1994)?
the arousing story/placebo group showed a memory advantage (related to the greater emotional content in their version of the story)
the arousing-story/drug group did not show this benefit (presumably, because the drug suppressed their amygdala activity)
interestingly, the subjective ratings of the emotionality of the story in the arousing-story/drug group did not differ from the arousing-story/placebo group
suggests the effects are (at least somewhat) constrained to mechanisms related to memory formation, rather than the “in the moment” experience
What are common factors in processing what could be broadly described as fear?
trustworthiness judgments
viewing of faces expressing fear
recall of stories involving more or less emotional content (which involved graphic descriptions of injury)
Why would evolution have shaped the amygdala to be so sensitive to fear?
although people who are afraid are not necessarily likely to pose a specific threat to you, whatever is influencing their experience of fear might be relevant for our survival
What were the results of the study involving fear processing in patients with amygdala damage?
we recently saw that patients with amygdala damage, in contrast to healthy controls, do not show the typical elevated amygdala activity in response to faces expressing fear
healthy controls also produce this kind of response when fearful faces are only shown for very brief periods of time (e.g. 33 ms) and masked
this kind of stimulus presentation results in participants reporting no subjective awareness of seeing the fearful face, yet still activates the amygdala
these kinds of results suggest the fear is identified extremely rapidly and efficiently, and can even occur without conscious awareness
What was the hypothesis tested in the Whalen et al. (2004) study?
tested the hypothesis that the amygdala uses a heuristic related to “wide eyes” to make these rapid judgments
What was the stimuli used in the Whalen et al. (2004) study?
expressions associated with wide-eyes: anger, fear, surprise
expressions not associated with wide-eyes: happy, sad, neutral
eliminated all the other information contained in the stimuli the might be informative of emotion, other than eye wideness
manipulated the amount of sclera (whites of the eye) visible, presented for only 17 ms
What were the methods used in the Whalen et al. (2004) study?
show fearful or happy faces, with (eye blacks condition) or without (eye whites condition) the figure and ground luminance reversed
note that the “eye blacks” condition stimuli is identical to that in the “eye whites” condition, with one exception: coloration
i.e. shape, contour, etc. are all the same, and this therefore controls for the possibility that any other information besides coloration is being used
the “eye black” condition does not represent stimuli that exist in the natural world, and thus it was predicted that the amygdala will not respond in the same way to those stimuli
What were the results of the Whalen et al. (2004)?
as predicted, amygdala activation was greater for fearful faces as compared to happy, though only i the “eye whites” condition (as compared to the “eye blacks” condition)
supports the ides that this low-level visual cue (eye wideness), in an ecologically valid (i.e., natural) way, is something the amygdala is sensitive to
this same research group also found a similar effect for pupil dilation, suggesting another low-level visual cue that could help with the rapid interpretation of fear
What is the implicit association test (IAT)?
has been widely used in an attempt to study various kinds of implicitly held biases
the IAT attempts to quantify bias by looking for differences in response times across overlapping sets of response mappings
the mappings are then reversed and the critical question is, which response mapping (if either) are you fastest to use when classifying things as American: when it uses the same button that was recently associated with classifying things as “good” or “bad”?
this approach involves looking for compatibility effects
What is an example of an IAT looking for an “American bias”
press the left shift button for words that you associate with good things (left = good) and the right shift button for words you associate with bad things (right = bad)
depending on what stimuli is presented, you will also sometimes need to press the left shift button when seeing words you associate with Canadians (left = good or Canadian) and the right shift button for words you associate with Americans (right = bad or American)
you now need to press the left shift button for words you associate with Americans and good things (left = good or American) and the right shift button for Canadians and bad things (right = bad or Canadian things)
if you’re faster to classify Americans using the same button you’ve just associated with “bad things”, that is supposed to mean that you have a preexisting association between Americans and bad things, meaning you have a bias against them (at least in theory)
How is the IAT used to measure racial bias?
Valanced (i.e. good/bad) judgments are made about various unrelated stimuli, such as pictures that are categorized as positive or negative (e.g. using the right and left shift buttons)
judgments about the construct being examined for bias are also made, such as categorizing faces as either black or white (e.g. using the right and left shift buttons)
the mappings are reversed several times and analyses focus o whether a compatibility effect is associated with either response mapping
What are the results of using IAT to measure racial bias?
some published work has found that white participants can be faster to categorize stimuli as “black” when using the same button that is also currently being used (and/or was recently used) to categorize things as “bad”
although controversial, this has been argued as evidence for “implicitly held racial bias”
What did the Phelps et al. (2000) study find?
tested white Americans viewing unfamiliar faces (half of which were also white, half of which were black)
What was experiment 1 in the Phelps et al. (2000) study?
replicated the typical findings of evidence for racial bias in participants, inferred via differences in RT across button mappings
the extent of bias observed (again, based on magnitude of RT effect) was found to be correlated to a sort of standardized racism scale (the Modern Racism Scale)
they found that these scores correlated with the extent to which amygdala activation was greater for black, as compared to white, faces
What was experiment 2 in the Phelps et al. (2000) study?
they also tried replicating the experiment with familiar (famous) faces that were generally positively regarded (e.g., role models, etc.)
found less evidence for bias, scores no longer correlated with amygdala activation
What were the implications of the results of the Phelps et al. (2000) study?
E1 and E2 suggest early and relatively automatic contributions from amygdala activation can bias our judgments, yet higher-level cognition (e.g., knowledge of reputation) can also factor in, which may be more likely to occur in certain situations (when we know the person)
How can we operationalize emotions through motivations?
one way to think about emotions is that they influence motivation, which in turn, shapes behavior
the distinction between what are referred to as approach and avoid behaviors could be relevant here
What are approach behaviors?
associated with positively valanced affect, encourages approach
What are avoid behaviors?
associated with negatively valanced affect, encourages avoidance
How are approach and avoid behaviors seen in the general population?
positive approach-related emotions associated with elevated activity in the left PFC
negative avoidance-related emotions associated with elevated activity in the right PFC
How are approach and avoid behaviors seen in clinical populations?
resting EEG studies suggest overactivity in the right PFC (at least in some cases)
a common symptom of damage to the left frontal cortex is depression
How is the process of extinction relevant to the control of emotions?
fear-based responses can be understood within the context of this approach/avoid framework as being particularly important (e.g. fear of a predator encourages you to keep your distance, which should help keep you safer than if you did not experience that fear)
however, to accommodate the dynamic and complex nature of our world, we also need to be able to flexibly adapt our behavior to our changing environments and circumstances
this includes learning new associations (that may involve affective responses that encourage approach/avoid behaviors), e.g. acquiring a classically conditioned response
however, also potentially very important is the unlearning of previous associations that are no longer relevant, and/or subject to the same interpretation as they once were, e.g. extinction of a classically conditioned response
What is extinction?
extinction refers to the gradual reduction in a conditioned fear response, as the CS (conditioned stimulus) continues to be presented without the associated US (unconditioned stimulus)
this process was originally viewed in much the same way a semantic or episodic memory can be forgotten (e.g. simple decay)
however, several lines of evidence recast this as representing a more active learning process (e.g. spontaneous recovery, “savings” when relearning in the form of more rapid reacquisition of associations previously learned, etc.)
How does Post Traumatic Stress Disorder relate to the importance of extinction?
PTSD is a particularly salient example of what harm can come from an inability to extinguish what may have originally been an appropriate fear-based response, that no longer is
for example, imagine someone who has left home because of a war and still gets “triggered” by sounds of battle in their new location, even if it’s just coming from a movie
rapidly and automatically slipping into a state of hyper-vigilance in a war zone would indeed be adaptive, and perhaps even required for survival
however, in a civilian environment in which this state is not normally required (or eve helpful), this ca create tremendous problems
What is the recurrent (feedback) loop between the paralimbic cortex and the amygdala?
deactivation of this region reduces the impact of conditioned fear on observable behavior (e.g. freezing behavior, a common method to operationalize fear)
macrostimulation of this region increases freezing behavior, as well as interferes with extinction
neurons in this region show a pattern of sustained firing in response to a CS that has been associated with fear conditioning (and the time course of this sustained firing correlates with the duration of freezing behavior)
What are the similarities between dACC activity in humans and PL activity in rodents?
both play a role in prioritizing previously learned associations over more recent ones
activity in this region is correlated with both skin-conductance and behavior corelates of fear conditioning
this region is very responsive to aversive US
activation in the dACC also increases when a CS is presented without the (expected) UCS, which may form a sort of error signal
What are the similarities between vmPFC activity in humans and infralimbic (IF) cortex activity in rodents?
seems to be involved with prioritizing a more recently learned (new) CS-neutral stimulus pairing
activity in this region is suppressed during fear conditioning and elevated during extinction learning, as well as when retrieving a “new” association
some individual differences also evident
while retrieving a “new” association, the amount of activation correlates with behavioral measures of success at inhibiting the “old” association (as measured by behavioral response)
the cortical thickness of this region is positively correlated with efficiency of extinction learning
How was Kluvery Bucy Syndrome discovered?
Kluver was interested in studying visual imagery in children and, as an extension of this line of work, became interested in the effects of mescaline (the hallucinogenic compound found in various cacti, e.g. peyote) on imagery
he notices that mescaline ingestion sometimes led to chewing and licking behaviors in monkeys, along with olfactory/gustatory-related hallucinations, which he though were caused by this substance inducing a type of seizure known as uncinate fits
because it was thought that these seizures were related to activity of the uncus, Kluver began collaborating with Paul Bucy on various temporal lob lesions studies
Bucy thought the uncus was too small to accurately lesion and therefore defaulted to removing the entire temporal lobe
as often happens in science, in a somewhat indirect way, this work led to an understanding of Kluvery Bucy Syndrome
What are the symptoms of Kluver Bucy Syndrome?
associative agnosia (originally termed “psychic blindness”)
docility (being overly passive/tame)
hyperorality (putting everything in your mouth, including dangerous objects e.g., the wrong end of a lit cigarette)
dietary changes (including hyperphagia, consuming in excess)
hypersexuality
How is amygdala dysfunction involved in Kluver Bucy Syndrome?
although originally linked to the temporal lobe damage/removal, the symptoms of Kluver Bucy Syndrome can be largely localized to the amygdala
one way to interpret this patter of behavioral changes is they demonstrate the importance of the amygdala for the processing of the rewarding and/or punishing value of various stimuli
it has also been suggested that it reflects behavior that is more strongly influenced b more “instinctual” or “primitive” drives, e.g. eating, sex, aggression (which are strongly influenced by contributions from the hypothalamus, which would still usually be intact in these populations)
What was the Ochsner et al. Model of controlling emotions?
Ochsner et al. have proposed a model, built largely on more general principles of cognitive control, that includes such neurologically relevant mechanisms as:
attentional selection
attentional filtering
cognitive change
cognitive reappraisal
response modulation
What did the Slegter et al. (2007) study show about attentional blink and emotions?
although not directly tied to emotion, the results of Slegter et al. (2007) demonstrate reductions in the attentional blink following extensive practice with meditation: Vipassana meditation for 10-12 hours/day, for three months
in addition to behavioral measures, ERP’s related to the targets also show change when comparing pre-training to post-training
smaller P3 for T1 targets (for meditators) on trials in which T2 was also detected
more efficient attentional selection left more residual resources to help detect the T2 target?
What are the results of the Slegter et al. (2007) study on attentional blink and emotions?
this implicates some flexibility in our attentional window, which ca be altered by practicing something as “simple” as meditation
if we can modulate how we attend to stimuli in an attentional blink task (very neutral, just letters and numbers), we should be able to modulate how we engage with other stimuli that has the potential to induce affective changes
in brief, we should pay less attention to the things that upset us, and more attention to what makes us feel good!
