Identifying temporal and causal contributions of neural processes underlying the Implicit Association Test (IAT)

Temporal dynamics of attitude decisions: A test of the iterative reprocessing model using event-related potentials

Although evaluative judgments are a central component of everyday decision making little is known about the temporal dynamics of the processes used to make them. The present study used the high temporal resolution of event-related brain potentials (ERPs) to test Cunningham and Zelazo's (2007) posited differences in the timing of attitude tag retrieval relative to stimulus categorization for 'attitudes' and 'evaluations,' as well as tenets of their Iterative Reprocessing (IR) loop model. Participants made agree/disagree decisions about their attitudes and You/Not You decisions about their autobiographical memories in separate reaction time (RT) tasks while brain activity was recorded from 32 scalp sites. A median-split analysis on RT was used to separate fast and slow decisions. Decisions about autobiographical stimuli produced the typical results in which retrieval and stimulus categorization occurred together just before the response regardless of decision difficulty. By contrast, the relative timing of tag retrieval and categorization differed with difficulty for attitude decisions as predicted by the model. Fast attitude decisions were processed similarly to fast You decisions with retrieval and categorization timing coupled to the response. Slow attitude decisions, however, differed because, while tag retrieval timing was the same as for fast attitude decisions, post-retrieval processing delayed stimulus categorization and a response by 450 msec. ERP activity over dorsolateral prefrontal cortex (DLPFC) in the pre-response interval was asymmetrical, with greater activity for attitude and autobiographical decisions over left and right hemispheres, respectively, while amplitude and duration increased with decision difficulty for both. Slow attitude decisions alone elicited a reduced pre-response positivity, a correlate of goal-directed response selection. The results provide empirical support for key aspects of Cunningham and Zelazo's (2007) attitude-evaluation dichotomy and the timing of the posited component processes in their IR model as well as novel information about the roles of stored tags and reflective processes in different attitude decisions.

Neural Rhythmic Underpinnings of Intergroup Bias: Implications for Peace-Building Attitudes and Dialogue

Intergroup bias is a ubiquitous socio-cognitive phenomenon that, while sustaining human dependence on group living, often leads to prejudice, inequity, and violence; yet, its neural underpinnings remain unclear. Framed within the Israeli-Palestinian conflict and targeting youth, this study utilized magnetoencephalography to describe intrinsic neural oscillatory processes that represent the intergroup bias and may link with engagement in peacemaking in order to shed further light on the neural mechanisms underpinning intergroup conflict. Across the oscillatory spectrum, from very low to very high frequency bands, the only rhythm found to underlie the intergroup bias was the alpha rhythm. Alpha was continuously activated across the task and integrated a rapid perceptual component in occipital cortex with a top-down cognitive-control component in medial cingulate cortex. These components were distinctly associated with real-life intergroup dialog style and expressed attitudes that promote active engagement in peacemaking. Our findings suggest that the cortical alpha rhythm plays a crucial role in sustaining intergroup bias and address its impact on concrete intergroup experiences. Results highlight the need to provide opportunities for active peace-building dialog to youth reared amidst intractable conflicts.

Anxiety Sensitivity and Arousal Symptom Implicit Association Task Performance: An Event-Related Potential Study of Cognitive Processing of Anxiety-Relevant Stimuli

BACKGROUND

Anxiety sensitivity (AS), or the fear of anxious arousal, is a transdiagnostic risk factor. Despite the proliferation of self-report research showing AS is related to anxiety, cognitive processes underlying AS are poorly understood. Specifically, AS may reflect processes related to early attentional orientation and response monitoring (reflecting automatic processes), or later engagement and assigning emotional salience towards stimuli (reflecting conscious processes).

METHODS

To elucidate cognitive processes underlying AS, event-related potential (ERP) components were elicited in the current study during a novel implicit association task (IAT) in which participants paired self (versus other) words with anxious arousal (versus calm) words. Analyses were then conducted in a sample of community adults (N = 67; M age 39.43, SD = 15.33, 61.2% female) to investigate the association between AS and ERP markers indicative of cognitive processing derived during the IAT.

RESULTS

AS was not related to performance on the arousal-IAT and that ERP components did not differ by IAT condition. AS predicted overall late positive potential (LPP) amplitude, particularly in the me/anxiety condition. Elevated IAT scores (reflecting greater ease pairing self-words with anxiety-words) predicted greater P300 amplitude in the me/anxiety condition.

LIMITATIONS

The sample was relatively small, and bottom-up processes were not assessed.

CONCLUSIONS

These findings are inconsistent with the claim that AS is related to top-down cognitive processes driving self-arousal automatic associations. Instead, AS may relate to cognitive processes regulating emotional engagement with stimuli. Further investigations of cognitive processes underlying AS are needed to inform novel interventions targeting AS.

Neural processing of gendered information is more robustly associated with mothers' gendered communication with children than mothers' implicit and explicit gender stereotypes

Processes like gender socialization (the ways in which parents convey information to their children about how girls and boys should behave) often happen unconsciously and might therefore be studied best with neuroscientific measures. We examined whether neural processing of gender-stereotype-congruent and incongruent information is more robustly related to mothers' gendered socialization of their child than mothers' implicit and explicit gender stereotypes. To this end, we examined event-related potentials (ERPs) of mothers (N = 35) completing an implicit gender-stereotype task and mothers' gender stereotypes in relation to observed gendered communication with their child (2-6 years old) in a naturalistic picture-book-reading setting. Increased N2 activity (previously related to attentional processes) to gender stimuli in the implicit gender-stereotype task was associated with mothers' positive evaluation of similar gendered behaviors and activities in the picture book they read with their child. Increased P300 activity (previously related to attention to unexpected events) to incongruent trials in the gender-stereotype task was associated with a more positive evaluation of congruent versus incongruent pictures. Compared to mothers' gender stereotypes, neural processing of gendered information was more robustly related to how mothers talk to their children about boys' and girls' stereotype-congruent and incongruent behavior, and masculine and feminine activities.

Clinical and therapeutic role of mentalization in schizophrenia-a review

Recent empirical findings from clinical and genetic studies suggest that mentalization, a key area of social cognition, is a distinct construct, although it is closely related to the neurocognitive deficits and symptoms of schizophrenia. Mentalization contributes a great deal to impaired social functioning. Current measures often display methodological problems, and many aspects should be taken into account when assessing mentalization. Moreover, advances in cognitive and affective neurosciences have led to the development of more advanced behavioral methods to assess the relationship between cognitive functions, symptoms, and social cognition based on their underlying neural mechanisms. The development of assessment tools that better examine the neural circuitry of such relationships may lead to the development of new psychosocial and pharmacological treatments.

Brain Regions Influencing Implicit Violent Attitudes: A Lesion-Mapping Study

Increased aggression is common after traumatic brain injuries and may persist after cognitive recovery. Maladaptive aggression and violence are associated with dysfunction in the prefrontal and temporal cortex, but such dysfunctional behaviors are typically measured by explicit scales and history. However, it is well known that answers on explicit scales on sensitive topics--such as aggressive thoughts and behaviors--may not reveal true tendencies. Here, we investigated the neural basis of implicit attitudes toward aggression in humans using a modified version of the Implicit Association Task (IAT) with a unique sample of 112 Vietnam War veterans who suffered penetrating brain injury and 33 healthy controls who also served in combat in Vietnam but had no history of brain injury. We hypothesized that dorsolateral prefrontal cortex (dlPFC) lesions, due to the crucial role of the dlPFC in response inhibition, could influence performance on the IAT. In addition, we investigated the causal contribution of specific brain areas to implicit attitudes toward violence. We found a more positive implicit attitude toward aggression among individuals with lesions to the dlPFC and inferior posterior temporal cortex (ipTC). Furthermore, executive functions were critically involved in regulating implicit attitudes toward violence and aggression. Our findings complement existing evidence on the neural basis of explicit aggression centered on the ventromedial prefrontal cortex. These findings highlight that dlPFC and ipTC play a causal role in modulating implicit attitudes about violence and are crucially involved in the pathogenesis of aggressive behavior.

SIGNIFICANCE STATEMENT

Maladaptive aggression and violence can lead to interpersonal conflict and criminal behavior. Surprisingly little is known about implicit attitudes toward violence and aggression. Here, we used a range of techniques, including voxel-based lesion-symptom mapping, to examine the causal role of brain structures underpinning implicit attitudes toward aggression in a unique sample of combat veterans with traumatic brain injury. We found that damage to the dorsolateral prefrontal cortex (dlPFC) led to a more positive implicit attitude toward violence that under most normal situations would be considered inappropriate. These results suggest that treatments aimed at increasing cognitive control using cognitive behavioral therapies dependent on the intact dlPFC could treat aggressive and violent behavior.

Clocking the social mind by identifying mental processes in the IAT with electrical neuroimaging

Why do people take longer to associate the word "love" with outgroup words (incongruent condition) than with ingroup words (congruent condition)? Despite the widespread use of the implicit association test (IAT), it has remained unclear whether this IAT effect is due to additional mental processes in the incongruent condition, or due to longer duration of the same processes. Here, we addressed this previously insoluble issue by assessing the spatiotemporal evolution of brain electrical activity in 83 participants. From stimulus presentation until response production, we identified seven processes. Crucially, all seven processes occurred in the same temporal sequence in both conditions, but participants needed more time to perform one early occurring process (perceptual processing) and one late occurring process (implementing cognitive control to select the motor response) in the incongruent compared with the congruent condition. We also found that the latter process contributed to individual differences in implicit bias. These results advance understanding of the neural mechanics of response time differences in the IAT: They speak against theories that explain the IAT effect as due to additional processes in the incongruent condition and speak in favor of theories that assume a longer duration of specific processes in the incongruent condition. More broadly, our data analysis approach illustrates the potential of electrical neuroimaging to illuminate the temporal organization of mental processes involved in social cognition.

Neural Patterns of the Implicit Association Test

The Implicit Association Test (IAT) is a reaction time based categorization task that measures the differential associative strength between bipolar targets and evaluative attribute concepts as an approach to indexing implicit beliefs or biases. An open question exists as to what exactly the IAT measures, and here EEG (Electroencephalography) has been used to investigate the time course of ERPs (Event-related Potential) indices and implicated brain regions in the IAT. IAT-EEG research identifies a number of early (250-450 ms) negative ERPs indexing early-(pre-response) processing stages of the IAT. ERP activity in this time range is known to index processes related to cognitive control and semantic processing. A central focus of these efforts has been to use IAT-ERPs to delineate the implicit and explicit factors contributing to measured IAT effects. Increasing evidence indicates that cognitive control (and related top-down modulation of attention/perceptual processing) may be components in the effective measurement of IAT effects, as factors such as physical setting or task instruction can change an IAT measurement. In this study we further implicate the role of proactive cognitive control and top-down modulation of attention/perceptual processing in the IAT-EEG. We find statistically significant relationships between D-score (a reaction-time based measure of the IAT-effect) and early ERP-time windows, indicating where more rapid word categorizations driving the IAT effect are present, they are at least partly explainable by neural activity not significantly correlated with the IAT measurement itself. Using LORETA, we identify a number of brain regions driving these ERP-IAT relationships notably involving left-temporal, insular, cingulate, medial frontal and parietal cortex in time regions corresponding to the N2- and P3-related activity. The identified brain regions involved with reduced reaction times on congruent blocks coincide with those of previous studies.

Cerebral correlates of faking: evidence from a brief implicit association test on doping attitudes

Direct assessment of attitudes toward socially sensitive topics can be affected by deception attempts. Reaction-time based indirect measures, such as the Implicit Association Test (IAT), are less susceptible to such biases. Neuroscientific evidence shows that deception can evoke characteristic ERP differences. However, the cerebral processes involved in faking an IAT are still unknown. We randomly assigned 20 university students (15 females, 24.65 ± 3.50 years of age) to a counterbalanced repeated-measurements design, requesting them to complete a Brief-IAT (BIAT) on attitudes toward doping without deception instruction, and with the instruction to fake positive and negative doping attitudes. Cerebral activity during BIAT completion was assessed using high-density EEG. Event-related potentials during faking revealed enhanced frontal and reduced occipital negativity, starting around 150 ms after stimulus presentation. Further, a decrease in the P300 and LPP components was observed. Source analyses showed enhanced activity in the right inferior frontal gyrus between 150 and 200 ms during faking, thought to reflect the suppression of automatic responses. Further, more activity was found for faking in the bilateral middle occipital gyri and the bilateral temporoparietal junction. Results indicate that faking reaction-time based tests alter brain processes from early stages of processing and reveal the cortical sources of the effects. Analyzing the EEG helps to uncover response patterns in indirect attitude tests and broadens our understanding of the neural processes involved in such faking. This knowledge might be useful for uncovering faking in socially sensitive contexts, where attitudes are likely to be concealed.

Characterizing switching and congruency effects in the Implicit Association Test as reactive and proactive cognitive control

Recent research has identified an important role for task switching, a cognitive control process often associated with executive functioning, in the Implicit Association Test (IAT). However, switching does not fully account for IAT effects, particularly when performance is scored using more recent d-score formulations. The current study sought to characterize multiple control processes involved in IAT performance through the use of event-related brain potentials (ERPs). Participants performed a race-evaluative IAT while ERPs were recorded. Behaviorally, participants experienced superadditive reaction time costs of incongruency and task switching, consistent with previous studies. The ERP showed a marked medial frontal negativity (MFN) 250-450 ms post-stimulus at midline fronto-central locations that were more negative for incongruent than congruent trials but more positive for switch than for no-switch trials, suggesting separable control processes are engaged by these two factors. Greater behavioral IAT bias was associated with both greater switch-related and congruency-related ERP activity. Findings are discussed in terms of the Dual Mechanisms of Control model of reactive and proactive cognitive control.

The neuroscience of prejudice and stereotyping

Despite global increases in diversity, social prejudices continue to fuel intergroup conflict, disparities and discrimination. Moreover, as norms have become more egalitarian, prejudices seem to have 'gone underground', operating covertly and often unconsciously, such that they are difficult to detect and control. Neuroscientists have recently begun to probe the neural basis of prejudice and stereotyping in an effort to identify the processes through which these biases form, influence behaviour and are regulated. This research aims to elucidate basic mechanisms of the social brain while advancing our understanding of intergroup bias in social behaviour.