The relation between proximity and brightness similarity in dot patterns

The Gestalt studies demonstrated the tendency to visually organize dots on the basis of similarity, proximity, and global properties such as closure, good continuation, and symmetry. The particular organization imposed on a collection of dots is thus determined by many factors, some local, some global. We discuss computational reasons for expecting the initial stages of grouping to be achieved by processes with purely local support. In the case of dot patterns, the expectation is that neighboring dots are grouped as a function of proximity and similarity of contrast, by processes that are independent of the overall organization and the various global factors. We describe experiments that suggest a purely local relationship between proximity and brightness similarity in perceptual grouping.     

The Greta Thunberg Effect: Familiarity with Greta Thunberg predicts intentions to engage in climate activism in the United States

Despite Greta Thunberg's popularity, research has yet to investigate her impact on the public's willingness to take collective action on climate change. Using cross-sectional data from a nationally representative survey of U.S. adults (N = 1,303), we investigate the “Greta Thunberg Effect,” or whether exposure to Greta Thunberg predicts collective efficacy and intentions to engage in collective action. We find that those who are more familiar with Greta Thunberg have higher intentions of taking collective actions to reduce global warming and that stronger collective efficacy beliefs mediate this relationship. This association between familiarity with Greta Thunberg, collective efficacy beliefs, and collective action intentions is present even after accounting for respondents’ overall support for climate activism. Moderated mediation models testing age and political ideology as moderators of the “Greta Thunberg Effect” indicate that although the indirect effect of familiarity with Greta Thunberg via collective efficacy is present across all age-groups, and across the political spectrum, it may be stronger among those who identify as more liberal (than conservative). Our findings suggest that young public figures like Greta Thunberg may motivate collective action across the U.S. public, but their effect may be stronger among those with a shared political ideology. Implications for future research and for broadening climate activists’ appeals across the political spectrum are discussed.     

Some recommendations for doing high‐impact research in social psychological science

In this article, I reflect upon my own career to distil some general recommendations for doing high‐impact social psychological research in the midst of a worldwide pandemic. My suggestions include (a) testing and deriving theories that can help explain real‐world human judgment and behaviour (answering questions that people care about), (b) preaching beyond the choir (communicating your research to audiences outside of social psychology), and (c) birds of a feather are stronger together (maximizing impact through strategic collaborations).     

Interference in implicit memory caused by processing of interpolated material

This study addresses the susceptibility of implicit memory to interference. Interference is manipulated by presenting interpolated lists of words that do or do not have word stems in common with previously studied target words (e.g., target word paragraph followed by interpolated words such as paradise or vicinity). Interference in a word stem completion task occurred only when words had similar word stems (Experiment 1). Increasing the number of interpolated words with corresponding word stems (e.g., not only paradise but also parking, pardon, and parliament) produced increasing amounts of interference (Experiment 2). Interference in implicit memory appears to be a simple response competition phenomenon that occurs when cues simultaneously activate primed targets and primed competing responses. The amount of interference can be explained by a quantitative model of the relative strengths of target and competing responses.     

A computational account of altered error processing in older age: Dopamine and the error-related negativity

When participants commit errors or receive feedback signaling that they have made an error, a negative brain potential is elicited. According to Holroyd and Coles’s (in press) neurocomputational model of error processing, this error-related negativity (ERN) is elicited when the brain first detects that the consequences of an action are worse than expected. To study age-related changes in error processing, we obtained performance and ERN measures of younger and high-functioning older adults. Experiment 1 demonstrated reduced ERN amplitudes in older adults in the context of otherwise intact brain potentials. This result could not be attributed to uncertainty about the required response in older adults. Experiment 2 revealed impaired performance and reduced response- and feedback-related ERNs of older adults in a probabilistic learning task. These age changes could be simulated by manipulation of a single parameter of the neurocomputational model, this manipulation corresponding to weakened phasic activity of the mesencephalic dopamine system.     

Intentional and unintentional contributions to nonspecific preparation: electrophysiological evidence

The authors hypothesized that there are distinct intentional and unintentional influences on nonspecific preparation for a future event. In 2 experiments, participants responded to an imperative stimulus (S-sub-2) that was presented equiprobably either 400 ms or 1,200 ms after the offset of a warning stimulus (S-sub-1). During the S-sub-1-S-sub-2 interval, the authors measured the contingent negative variation (CNV), an event-related brain potential reflecting nonspecific preparation. S-sub-1 provided either no information or reliable information about the duration of the impending S-sub-1-S-sub-2 interval, thereby allowing an intentional influence on the state of preparation. The effect of S-sub-1 information on the CNV was approximately additive to the effect of the S-sub-1-S-sub-2 interval that was used on the preceding trial. This supports the view that the preceding S-sub-1-S-sub-2 interval contributes unintentionally to the state of nonspecific preparation guided by a process of trace conditioning.     

A goal activation approach to the study of executive function: an application to antisaccade tasks

We argue that a general control process, responsible for the activation and maintenance of task goals, is central to the concept of executive function. Failures of this process can become manifest as goal neglect: disregard of a task requirement even though it has been understood (Duncan, 1995). We discuss the results of several published and new experiments using various versions of the antisaccade task in order to investigate the circumstances under which goal neglect is likely to occur. Potentially conflicting results in the literature on adaptive control of saccadic eye movements are argued to be attributable to the extent to which different task versions elicit goal neglect. The results suggest an increased susceptibility to goal neglect of high-functioning older adults (Experiment 1) and of first-episode schizophrenia patients (Experiment 2), but not of patients with obsessive-compulsive disorder (Experiment 3). However, the degree to which such differences in susceptibility become manifest in task performance, is shown to be strongly influenced by manipulations of the relative saliency of task requirements. Theoretical and methodological implications for the study of executive function are discussed.     

Effects of mixed versus blocked design on stimulus evaluation: combining underadditive effects

According to the asynchronous discrete coding model of Miller, two manipulations should display underadditive effects on reaction time if they slow down noncontingent stages associated with the processing of two separable dimensions of a stimulus. Underadditive effects are also predicted by a dual route model when a task variable is factorially varied with design type (mixed vs blocked). Interpretations of both underadditive effects and their combination were evaluated. Intact and degraded stimuli were presented to 18 young adults either in a single block (mixed) or in separate blocks (blocked). Spatial stimulus-response (S-R) compatibility was manipulated in all conditions. Stimulus degradation and S-R compatibility interacted underadditively, but only in blocked presentations. Both interpretations of underadditive effects were supported. Eye-movement registrations provided additional support for the alternative routes model.     

Electrophysiological correlates of anterior cingulate function in a go/no-go task: Effects of response conflict and trial type frequency

Neuroimaging and computational modeling studies have led to the suggestion that response conflict monitoring by the anterior cingulate cortex plays a key role in cognitive control. For example, response conflict is high when a response must be withheld (no-go) in contexts in which there is a prepotent tendency to make an overt (go) response. An event-related brain potential (ERP) component, the N2, is more pronounced on no-go than on go trials and was previously thought to reflect the need to inhibit the go response. However, the N2 may instead reflect the high degree of response conflict on no-go trials. If so, an N2 should also be apparent when subjects make a go response in conditions in which nogo events are more common. To test this hypothesis, we collected high-density ERP data from subjects performing a go/no-go task, in which the relative frequency of go versus no-go stimuli was varied. Consistent with our hypothesis, an N2 was apparent on both go and no-go trials and showed the properties expected of an ERP measure of conflict detection on correct trials: (1) It was enhanced for low-frequency stimuli, irrespective of whether these stimuli were associated with generating or suppressing a response, and (2) it was localized to the anterior cingulate cortex. This suggests that previous conceptions of the no-go N2 as indexing response inhibition may be in need of revision. Instead, the results are consistent with the view that the N2 in go/no-go tasks reflects conflict arising from competition between the execution and the inhibition of a single response.