Neurobiology of unconscious bias

• Implicit response


  Quick, involuntary (unconscious) reaction to a stimulus. Does not require cognitive processing.
• Implicit Association Test (IAT)


  Measures subconscious attitudes & beliefs - association between mental concepts (e.g., female, male) & attributes (e.g., good, bad). Provides index of individual differences in the ease of association, such as 'black' / 'good' v. 'white' / 'good'.
• IAT is often done using EEG or fMRI techniques to measure neural activity
• System 1 thinking


  Low-effort heuristic (rule-of-thumb) processes used when fast decisions are needed
• System 2 thinking


  Deliberate processes that may monitor & revise the output of the (default) heuristic processing type in complex or unfamiliar situations or if sufficient time is available
• Biases occur in situations when deliberate processing either fails to successfully engage (e.g., time-limited), or fails to override the biased heuristic response
• fMRI


  • Detects changes associated with blood flow (blood O2). Provides good spatial, but poor temporal, resolution.
• ERP


  • Measured via stereotyped electrophysiological response to a specific stimulus. Provides excellent temporal (but not spatial) resolution.
• EEG


  • Test that detects brain electrical activity using electrodes attached to scalp. Measures voltage fluctuations resulting from ionic current within neurons.
• Affective empathy


  The ability to resonate with what a person is feeling. Very sensory (e.g., physical pain).

  
• Cognitive empathy


  The ability to take someone else's perspective & understand what the person is thinking. Relies partially on neural processes involved in Theory of Mind.

  
• "The affective & cognitive processes involved in understanding & sharing the emotional states of others, which produces motivation for helping others in need"
• Ingroup/Outgroup


  e.g., gender, age, profession, ethnicity, status, country of birth, sports team, social group & education can be used to categorise people as belonging either to the ingroup or the outgroup.
• A quick evaluation of ingroup membership was adaptive long ago (competing for or defending resources), but clearly less so now.
• We literally 'see', or perceive, the actions of ingroup members differently than those of outgroup members - & we empathise more with ingroup members (but we can teach ourselves out of much of this…).
• fMRI shows greater activity to faces of one's own racial group (ingroup) — an effect associated with better recognition of ingroup faces than outgroup faces.
• N170 component of the ERP shows enhanced processing of ingroup vs outgroup faces. Larger N170 ERP amplitudes in response to viewing black vs white faces have been observed in subjects with stronger implicit prejudice & in subjects who were made to feel anxious about appearing biased.
• Findings suggest that visual processing of race is malleable & depends on social motivations & contexts.
• Prefrontal cortex (PFC)


  • Receives afferents from all sensory organs, enabling it to rapidly respond to immediate threats in advance of more elaborative processing of a stimulus.
• Anterior cingulate cortex (ACC)


  • Monitors for racial bias: detects conflict, passes to dlPFC - top-down executive control.
• The ACC seems to detect conflict between implicit race attitudes & conscious intentions to be non-biased (mindful/conscious deliberation & evaluation). When such conflicts are detected, the dlPFC may regulate negative implicit judgements.
• Prejudice


  An attitude towards a person on the basis of their group membership.
• Amygdala


  • Responds rapidly to immediate threats in advance of more elaborative processing of a stimulus. In the social domain, it is critical for acquisition, storage & expression of classical fear conditioning (including social).
• Orbital Frontal Complex


  • Supports monitoring of social cues & subsequent adjustment of behaviour. Seems to support more complex and flexible evaluative representations than the amygdala.
• Insula


  • Represents somatosensory states (including visceral responses) & emotions related to such states (e.g., disgust). Also implicated in prosocial emotions, such as empathy, towards liked individuals.
• Striatum


  • Associated with the computation of value (that is, value placed on a potential action) & anticipated outcomes.
• Medial prefrontal cortex (mPFC)

  • The medial region of the prefrontal cortex is involved in social cognition; the dorsal part is engaged in mental state reasoning; the ventral part is engaged in self-reflection. Involved in social emotions, moral empathy, reward processing & pleasure.
• Stereotyping network


  The structures in this putative 'intergroup' network may support the storage, activation & behavioural expression of social stereotypes.
• Semantic information stored in the lateral temporal lobe — representations of stereotype-related knowledge about people & social groups in the anterior temporal lobe (ATL) — is recruited into the dorsal medial prefrontal cortex (mPFC) to support the formation of impressions (i.e., stereotypes) & also into the inferior frontal gyrus (IFG) to support goal-directed actions guided by stereotypes.
• Knowledge of social stereotypes appears to reside in the ATL, which provides influencing input to the mPFC.
• The application of stereotypes to behaviour seems to involve regions of the lateral PFC (specifically, the IFG) associated with goal representation & response inhibition to support goal-directed action: 'thinking is for doing'.
• Regulation network


  • Neural network that supports the regulation of intergroup responses - self-regulation of behaviour. Involves the dorsolateral prefrontal cortex (DLPFC).
• Expression of social stereotypes

  Semantic information stored in the lateral temporal lobe - representations of stereotype-related knowledge about people & social groups in the anterior temporal lobe (ATL) - is recruited into the dorsal medial prefrontal cortex (mPFC) to support the formation of impressions (i.e., stereotypes) & also into the inferior frontal gyrus (IFG) to support goal-directed actions guided by stereotypes
• Stereotyping network


  • Knowledge of social stereotypes appears to reside in the ATL, which provides influencing input to the mPFC
  • The application of stereotypes to behaviour seems to involve regions of the lateral PFC (specifically, the IFG) associated with goal representation & response inhibition to support goal-directed action: 'thinking is for doing'
• Regulation network


  • Intergroup response goals are represented in the prefrontal cortex & implemented into behaviour in coordination with the striatum & motor cortex
  • Conflicts between bias & goals or external cues (e.g., social norms) processed in the dorsal anterior cingulate cortex (dACC) & rostral ACC (rACC), respectively
  • The medial prefrontal cortex (mPFC) is involved in perspective-taking & mentalising
• Regulation network


  1. The ACC monitors response conflict

  2. As the conflict signal in the ACC rises, the ACC engages regions for goal-directed behaviour, such as PFC (involved in high-level goal representation) which connects to the striatum, through which top-down control is implemented in behaviour
• Regulation network


  • Lateral PFC associated with working memory, response selection & the representation of high-level goals
  • Governs most human goal-directed responses - coordinates the control of action & attention
• The large medial PFC contributes to both stereotyping & prejudice, as well as regulatory processes. Not well understood.
• Gender stereotypes


  Targets violating gendered expectations interact with mothers' gender stereotypes and beliefs
• The more stereotyped the expectation of gender


  The stronger the neural response to targets violating gender expectations