Intergroup processes and the happy face advantage: How social categories influence emotion categorization.

There is abundant evidence that emotion categorization is influenced by the social category membership of target faces, with target sex and target race modulating the ease with which perceivers can categorize happy and angry emotional expressions. However, theoretical interpretation of these findings is constrained by gender and race imbalances in both the participant samples and target faces typically used when demonstrating these effects (e.g., most participants have been White women and most Black targets have been men). Across seven experiments, the current research used gender-matched samples (Experiments 1a and 1b), gender- and racial identity-matched samples (Experiments 2a and 2b), and manipulations of social context (Experiments 3a, 3b, and 4) to establish whether emotion categorization is influenced by interactions between the social category membership of perceivers and target faces. Supporting this idea, we found the presence and size of the happy face advantage were influenced by interactions between perceivers and target social categories, with reliable happy face advantages in reaction times for ingroup targets but not necessarily for outgroup targets. White targets and female targets were the only categories associated with a reliable happy face advantage that was independent of perceiver category. The interactions between perceiver and target social category were eliminated when targets were blocked by social category (e.g., a block of all White female targets; Experiments 3a and 3b) and accentuated when targets were associated with additional category information (i.e., ingroup/outgroup nationality; Experiment 4). These findings support the possibility that contextually sensitive intergroup processes influence emotion categorization. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Preparing a task is sufficient to generate a subsequent task-switch cost affecting task performance.

This study investigated the nature of switch costs after trials on which the cued task had been either only prepared (cue-only trials) or both prepared and performed (completed trials). Previous studies have found that task-switch costs occur following cue-only trials, demonstrating that preparing-without performing-a task is sufficient to produce a subsequent switch cost. However, it is not clear whether switch costs after these different types of trial reflect an impact of task-switching upon task preparation or task performance on the current trial. The present study examined this question using a double-registration procedure with both cue-only and completed trials. Participants responded to both task-cue and target stimuli. In cue responses, a cost of switching task cues (cue-switch cost) but not of switching tasks (task-switch cost) followed both cue-only and completed trials. In target responses, a task-switch cost but no cue-switch cost followed both cue-only trials and completed trials, and this task-switch cost was larger following completed than cue-only trials. The presence of the task-switch cost in target responses following cue-only trials indicates a specific impact of previous preparation upon task performance, and the increased size of this cost following completed trials indicates an additional impact of previous performance. Together, these results suggest that both task preparation and task performance contribute to the subsequent task-switch cost affecting task performance. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Investigating task preparation and task performance as triggers of the backward inhibition effect.

Backward inhibition is posited to aid task switching by counteracting the tendency to repeat a recent task. Evidence that factors such as cue transparency affect backward inhibition seems to imply that it is generated during task preparation, making its absence following trials on which a prepared task was not performed (nogo trials) surprising. However, the nogo method used in previous studies might have prevented detection of preparation-driven effects. We used a truncated-trial method instead, omitting stages of a trial with no need for a nogo signal. In Experiment 1, an n - 2 repetition cost (suggested to indicate backward inhibition) followed trials truncated after response selection, indicating that response execution is not necessary to trigger backward inhibition. In Experiments 2 and 3, no n - 2 repetition cost was obtained following trials truncated after cue presentation. To ensure some task preparation on cue-only trials, Experiment 4 used a double-registration procedure where participants responded to the task cue and the target on each trial. In contrast to Experiments 2 and 3, a small n - 2 repetition cost followed trials truncated after cue responses, affecting cue responses on the current trial. In addition, the n - 2 repetition cost was increased at cue responses and became evident at target responses when the preceding trial also involved a target response. These results imply that backward inhibition might be generated by processes occurring up to and including a cue response, affecting subsequent cue responses, as well as during task performance itself, affecting subsequent cue and target responses.

The effect of performing versus preparing a task on the subsequent switch cost.

Behaviour occurs not as isolated incidents, but within an ongoing sequence of events. The task-switching paradigm provides a useful way to investigate the impact of different events upon subsequent performance. An implication of two-stage task-switching models is that preparing a task without performing it might affect task readiness only to a limited extent. However, recent research has surprisingly shown larger switch costs following preparation ("cue-only" trials) than following performance ("completed" trials). We set out to conduct a rigorous comparison of the size of switch costs following cue-only versus completed trials. In Experiments 1 and 2, we controlled the timing between critical trial events. This had the effect of roughly equating, but not reversing, the relative size of switch costs. In Experiment 3, we restructured the paradigm to equate the predictability of cue and target events. Switch costs following cue-only trials were now smaller than those following completed trials. These studies confirm that task preparation alone is sufficient to drive subsequent switch costs. They also indicate that task performance might increase the size of these costs, consistent with two-stage task-switching models. Switch costs appear to be affected by both the timing and predictability of trial events.

Task cues lead to item-level backward inhibition with univalent stimuli and responses.

Backward inhibition may aid our ability to switch between tasks by counteracting the tendency to repeat a recently performed task. Current theory asserts that conflict between tasks during performance plays a key role in inducing the effect. However, a study by Costa and Friedrich suggests that backward inhibition might occur without this type of conflict being present. To better understand the mechanisms underlying backward inhibition, we investigated the roles of between-task conflict, task-based instructions, and task cues. Experiment 1 tentatively supported the view that conflict between tasks is not necessary for backward inhibition to be present, and suggested that either the use of task-based instructions or the provision of specific task cues might be sufficient to generate the effect. Experiment 2 ruled out task-based instruction as a likely cause of backward inhibition in this context. Experiment 3 showed that the provision of task cues was sufficient to drive a significant backward inhibition effect, but only when stimuli and responses (as well as tasks) repeated. Overall, these results indicate that between-task conflict during performance is not necessary for backward inhibition to be applied, and that task cues have a key role in generating the effect.

Task-switch costs subsequent to cue-only trials.

There is abundant evidence that there is a performance cost associated with switching between tasks. This "switch cost" has been postulated to be driven by task performance on the preceding trial, but recent research challenges any necessary role of previous task performance in driving the cost. Across three experiments, we investigated whether it is difficult to switch from a task that was prepared but never performed. We replicated the finding of a switch cost following cue-only trials (involving no task performance) whilst controlling for a potential cue-switching confound. This cost was larger than that following completed trials when preparation interval was short (300 ms), and it reduced significantly with a longer preparation interval (1000 ms) on the current trial. We also found that preparing only to attend to a particular visual dimension (colour or shape) was sufficient to drive a significant subsequent switch cost, which appeared to be residual in nature; we speculate that this cost may reflect the persistence of unfulfilled task intentions and/or a strategic slowing when consecutive intentions conflict.

Covert judgements are sufficient to trigger subsequent task-switching costs.

This research examines whether we have a tendency to repeat mental processes leading to decisions or judgements that are not accompanied by overt behaviours. We adapted the task-switching paradigm so that on selected trials task processing would be terminated prior to response execution. Switch costs were present subsequent to trials where task processing was terminated either at the stage of response selection or at the earlier stage of making a covert judgement (a mental decision) about the target stimulus. These costs were residual, as they occurred despite long preparation intervals, and they did not result from cue-switching or feature-repetition effects. We conclude that the same type of control mechanism may be recruited to select between potential alternative tasks whenever a stimulus needs to be processed in a task-specific way, regardless of whether or not an overt response is required.

Two measures of task-specific inhibition.

Inhibition has been implicated as an important mechanism for task-set control, ensuring the efficient selection of the to-be-performed task over alternative possibilities. Across three experiments we demonstrated the effects of two potentially different types of task inhibition. The first is the inhibition of a task that concurrently affords an incongruent response, which is labelled dimension inhibition (Goschke, 2000). Using targets that afford three tasks, we demonstrated that this only occurs when a single alternative task affords an incongruent response, with the inhibition being specific to that task. The second type of inhibition that we observed was backwards inhibition-the suppression of a recently abandoned task-set (Mayr & Keele, 2000). Unlike dimension inhibition, backwards inhibition was not triggered by the response incongruence of the unperformed tasks, or even whether the target afforded responses via the unperformed tasks. These two purported types of inhibition did not co-occur, and neither did the factors of response congruence and whether that task was recently abandoned interact. We therefore suggest that task-specific inhibition can be applied/triggered differently depending upon the paradigm, perhaps depending upon the extent to which alternative tasks, and therefore potentially other responses, are triggered by the target.

Feedback-related negativity codes prediction error but not behavioral adjustment during probabilistic reversal learning.

We assessed electrophysiological activity over the medial frontal cortex (MFC) during outcome-based behavioral adjustment using a probabilistic reversal learning task. During recording, participants were presented two abstract visual patterns on each trial and had to select the stimulus rewarded on 80% of trials and to avoid the stimulus rewarded on 20% of trials. These contingencies were reversed frequently during the experiment. Previous EEG work has revealed feedback-locked electrophysiological responses over the MFC (feedback-related negativity; FRN), which correlate with the negative prediction error [Holroyd, C. B., & Coles, M. G. The neural basis of human error processing: Reinforcement learning, dopamine, and the error-related negativity. Psychological Review, 109, 679-709, 2002] and which predict outcome-based adjustment of decision values [Cohen, M. X., & Ranganath, C. Reinforcement learning signals predict future decisions. Journal of Neuroscience, 27, 371-378, 2007]. Unlike previous paradigms, our paradigm enabled us to disentangle, on the one hand, mechanisms related to the reward prediction error, derived from reinforcement learning (RL) modeling, and on the other hand, mechanisms related to explicit rule-based adjustment of actual behavior. Our results demonstrate greater FRN amplitudes with greater RL model-derived prediction errors. Conversely expected negative outcomes that preceded rule-based behavioral reversal were not accompanied by an FRN. This pattern contrasted remarkably with that of the P3 amplitude, which was significantly greater for expected negative outcomes that preceded rule-based behavioral reversal than for unexpected negative outcomes that did not precede behavioral reversal. These data suggest that the FRN reflects prediction error and associated RL-based adjustment of decision values, whereas the P3 reflects adjustment of behavior on the basis of explicit rules.

Attention, competition, and the parietal lobes: insights from Balint's syndrome.

Simultanagnosia (resulting from occipito-parietal damage) is a profound visual deficit, which impairs the ability to perceive multiple items in a visual display, while preserving the ability to recognise single objects. Here we demonstrate in a patient presenting with Balint's syndrome that this deficit may result from an extreme form of competition between objects which makes it difficult for attention to be disengaged from an object once it has been selected.

Event related potentials reveal that increasing perceptual load leads to increased responses for target stimuli and decreased responses for irrelevant stimuli.

Lavie (1995) have suggested that perceptual processing is influenced by perceptual load. Specifically, relevant information receives additional processing in high load situations exhausting the available capacity. On the other hand, irrelevant information receives less processing with increasing load on a relevant task, as there is a reduced amount of residual processing available. Rees et al. (1997) provided the first physiological evidence for this model, showing this pattern in a functional magnetic resonance imaging study. Likewise, Handy et al. (2001) offered supporting evidence measuring event related potentials (ERPs). Both of these studies presented irrelevant information in peripheral vision. Here we manipulated load while using the identical stimuli and the same task (a peripheral gap judgment task) with centrally presented irrelevant stimuli. ERPs show the pattern predicted by Lavie and colleagues, specifically for the N1 component. This work offers further evidence that visual attention modulates relatively early processing of perceptual information. Specifically, increasing load resulted in stronger N1 responses to relevant information and weaker N1 responses to irrelevant information.

Do women with fragile X syndrome have problems in switching attention: preliminary findings from ERP and fMRI.

Fragile X syndrome (FXS) is a neurodevelopmental disorder that represents the most common known cause of developmental delay. Recent neuropsychological findings indicate that females with FXS present with a specific pattern of cognitive deficits and that these difficulties primarily involve skills requiring executive control. The present study is the first to examine the extent to which neural activity of females with FXS can be observed on a task that specifically taps two core deficits, namely switching and response inhibition. Brain activity was measured using both event-related electrical potentials (ERPs) and event-related functional MRI (fMRI) neuroimaging in separate studies using the same cognitive paradigm. Compared to controls, females with FXS were significantly slower and made more errors on trials that required an immediate response (Go) to stimulus onset but were comparable on trials that required a delayed response (Wait) to stimulus onset. At the brain level, several areas showed significantly greater activation for females with FXS compared with controls, including the cingulate cortex and left and right ventral prefrontal areas. In contrast, no areas were found to show significantly greater activation for controls compared with females with FXS.

Mental representation of number in different numerical forms.

How are numerical operations implemented within the human brain? It has been suggested that there are at least three different codes for representing number: a verbal code that is used to manipulate number words and perform mental numerical operations (e.g., multiplication), a visual code that is used to decode frequently used visual number forms (e.g., Arabic digits), and an abstract analog code that may be used to represent numerical quantities. Furthermore, each of these codes is associated with a different neural substrate. We extend these studies using dense-sensor event-related EEG recording techniques to investigate the temporal pattern of notation-specific effects observed in a parity judgement (odd versus even) task in which single numbers were presented in one of four different numerical notations. Contrasts between different notations demonstrated clear modulations in the visual evoked potentials (VEP) recorded. We observed increased amplitudes for the P1 and N1 components of the VEP that were specific to Arabic numerals and to dot configurations but differed for random and recognizable (die-face) dot configurations. These results demonstrate clear, notation-specific differences in the time course of numerical information processing and provide electrophysiological support for the triple-code model of numerical representation.