R2.2 Classical Fear Conditioning (PSYC2050)

• The study investigated how animals use classical fear conditioning to associate environmental stimuli with aversive events
• The research examined how humans associate social in-group and out-group members with fearful events to advance the understanding of basic learning theory and social group interaction
• Primates readily associate stimuli from fear-relevant categories, such as snakes, with negative outcomes, unlike fear-irrelevant categories, like birds
• The readiness to associate fear extends to social groups defined by race
• Individuals from other racial groups are more readily associated with aversive stimuli than those of one's own race in both white and black Americans
• Close positive interracial contact might reduce this prepared fear response

Classical Fear Conditioning

• A neutral stimulus gains aversive properties when paired with an aversive event
• Classical conditioning research focuses on principles across different stimuli, but selective aversive learning is an exception
• Humans and non-human primates associate stimuli from fear-relevant categories like snakes and spiders with aversive events more readily than fear-irrelevant categories like birds and butterflies
• Race bias and fear conditioning rely on overlapping neural systems, providing a model for aversive learning in a socio-cultural context

The Study

• It assessed whether individuals of another race are more readily associated with aversive stimuli than individuals of one's own race
• It assessed whether these effects are moderated by attitudes, beliefs, or contact with racial outgroups
• Prepared fear learning manifests as a persistence in the learned fear response to fear-relevant conditioned stimuli
• The expectation was that if racial outgroups, but not in-groups, act like prepared stimuli, fear responses to outgroup faces would persist during extinction

Study Methodology

• Two experiments were conducted with differing stimuli
• The first recreated the standard preparedness effect for traditional fear-relevant stimuli
• The second tested the effect in the context of human social groups defined by race
• Experiment 1 presented snake, spider, bird, and butterfly images to subjects
• Experiment 2 presented black and white American participants with images of black and white unfamiliar male faces with neutral expressions
• One stimulus paired with mild electric shock, UCS, (reinforced conditioned stimulus, CS+) was adjusted to be uncomfortable but not painful
• The other stimulus presented without shock from each category (the unreinforced conditioned stimulus, CS-)
• Each CS presentation lasted six seconds and skin conductance responses (SCRs) were measured during the acquisition and extinction trials
• Conditioned fear response, CR, assessed as the differential SCR
• Experiment 2 involved measures of race attitudes, stereotypes, and contact with racial in-group and out-group members after completion of the extinction phase
• Within-subject design computed the relative conditioning race bias, linking it to individual race attitudes, stereotypes, and intergroup contact

Results

• Acquisition trials show participants had greater SCR to CS+ versus CS- for both fear-relevant [t(16)=5.81, P < 0.0001] and fear-irrelevant [t(16) = 4.24, P < 0.001] stimuli

Extinction Trials

• CRs to snakes and spiders failed to fully extinguish [t(16) = 2.81, P < 0.05]
• CRs to birds and butterflies extinguished [t(16) = 0.98, NS]
• There was a greater persistence of fear learning for fear-relevant, versus fear-irrelevant, stimuli

Social Group Experiment

• It plotted mean differential SCRs during acquisition and extinction to human faces from social groups
• There was greater SCR for the CS+ versus CS- for both racial in-group [t(72) = 5.28, P < 0.0001] and outgroup [t(72) = 8.10, P < 0.0001] faces during acquisition, indicating a CR to both
• There was a persistent significant CR to racial outgroup faces [t(72) = 3.87, P < 0.0001], whereas the CR to in-group races was fully extinguished [t(72) = -0.29, NS]

Prepared Learning Effect Observed

• Fear learning persisted during extinction for outgroup members, reflecting the patterns observed with snakes and spiders
• White participants acquired a greater SCR to the CS+ versus the CS- for both black [t(35) = 6.03, P<0.0001] and white [t(35) = 3.96, P < 0.001] faces during acquisition.
• CRs to black faces did not fully extinguish [t(35) = 2.85, P < 0.01], whereas their CRs to white faces did [t(35) = -0.91, NS]
• Black participants displayed a greater SCR to the CS+ versus the CS- for both black [t(36) = 3.52, P < 0.01] and white [t(36) = 5.44, P < 0.0001] faces, indicating acquisition of a CR
• Black participants CRs to white faces did not fully extinguish [t(36) = 2.59, P < 0.05], whereas their CRs to black faces did [t(36) = 1.10, NS]
• Unfamiliar racial outgroup members can serve as prepared stimuli in fear-learning situations
• Primate studies concur with selective association of stimuli from relevant natural categories with aversive outcomes

Brain Research

• Imaging has linked race bias in evaluating others with subcortical brain systems that mediate fear learning across species

Association of aversive events with outgroup members

• Propensity could lead to more negative evaluations of the outgroup, given otherwise equivalent properties of in-group and outgroup members
• Outgroup preparedness aligns with psychological mechanisms contributing to racial prejudice
• Conditioning bias to outgroup faces was the only measure that was significantly moderated by interracial dating
• The conditioning bias to fear racial outgroup members was attenuated among those with more interracial dating experience, consistent with research showing positive intergroup contact reduces negativity toward outgroups
• Individuals associate racial outgroup members more easily with aversive stimuli
• Demonstrations of prepared learning is evidence for biologically evolved learning mechanisms that treat certain natural categories of stimuli as prepared to be associated with an aversive outcome
• Conditioned responses to fear-relevant stimuli are insensitive to cognitive manipulations
• The prepared learning effect does not extend to most culturally defined fear-relevant stimuli
• A fear-relevant cultural artifact, can produce a resistance to extinction, suggests that cultural learning can imbue a stimulus with qualities engaging similar learning mechanisms
• Modern primates learn to fear spiders and snakes because such preparedness conferred a selective advantage
• Humans might have evolved a preparedness to fear others dissimilar to them or who appeared not to belong to their social group because such individuals were more likely to pose a threat
• Present-day members of another race, with physical differences and a common categorization that they belong to an outgroup, could activate such a mechanism and produce the robust conditioning effect
• Sociocultural learning about the identities and qualities of outgroups provides the basis for persistence of fear conditioning
• Individuals acquire negative beliefs about outgroups according to local cultures
• It is plausible that repeated exposure to information about outgroups might prepare individuals to fear newly encountered outgroup members
• Individual experiences can play a moderating role, such as intergroup contact
• Developing relationships with different others may weaken this otherwise strong predisposition