Earlier social information has a stronger influence on judgments.

People's decisions are often informed by the choices of others. Evidence accumulation models provide a mechanistic account of how such social information enters the choice process. Previous research taking this approach has suggested two fundamentally different cognitive mechanisms by which people incorporate social information. On the one hand, individuals may update their evidence level instantaneously when observing social information. On the other hand, they may gradually integrate social information over time. These accounts make different predictions on how the timing of social information impacts its influence. The former predicts that timing has no impact on social information uptake. The latter predicts that social information which arrives earlier has a stronger impact because its impact increases over time. We tested both predictions in two studies in which participants first observed a perceptual stimulus. They then entered a deliberation phase in which social information arrived either early or late before reporting their judgment. In Experiment 1, early social information remained visible until the end and was thus displayed for longer than late social information. In Experiment 2, which was preregistered, early and late social information were displayed for an equal duration. In both studies, early social information had a larger impact on individuals' judgments. Further, an evidence accumulation analysis found that social information integration was best explained by both an immediate update of evidence and continuous integration over time. Because in social systems, timing plays a key role (e.g., propagation of information in social networks), our findings inform theories explaining the temporal evolution of social impact and the emergent social dynamics.

Neurocognitive subgroups in major depressive disorder.

BACKGROUND: Major depressive disorder (MDD) is commonly associated with neurocognitive dysfunction. However, there remains substantial heterogeneity between patients and inconsistent findings regarding the magnitude and prevalence of specific neurocognitive deficits. This study aimed to investigate the potential for different neurocognitive subgroups in patients diagnosed with MDD. METHOD: Data were pooled from 4 different clinical trials that involved adults diagnosed with MDD. Neurocognitive outcomes included measures of verbal learning and memory, executive function, attention, and processing speed. Latent class analysis was conducted to examine for different subgroups based on neurocognitive profiles of performance across outcome measures. Subgroups were compared to a separate sample of age-matched adult healthy controls, across illness factors, and individual mood items on the Montgomery-Åsberg Depression Rating Scale (MADRS). RESULTS: Within the MDD cohort (N = 149), 45% of participants were considered relatively "cognitively preserved," with the remainder "cognitively reduced" (39%) or "cognitively impaired" (16%). Verbal memory performance was significantly poorer compared to attention and processing speed only in the "cognitively impaired" subgroup. There was no association between subgroup membership and relevant illness factors, including ratings on individual MADRS items. LIMITATIONS: Data were pooled from several studies that included different neurocognitive measures and cohorts. CONCLUSIONS: Approximately half of MDD participants had no or minimal objective cognitive difficulties, and neurocognitive functioning was found generally unrelated to illness factors. Future longitudinal research is warranted to determine whether the people who are relatively cognitively impaired are at increased risk for further cognitive decline. (PsycInfo Database Record (c) 2020 APA, all rights reserved).