Analyses of response time data in the same-different task.

The Same-Different task presents two stimuli in close succession and participants must indicate whether they are completely identical or if there are any attributes that differ. While the task is simple, its results have proven difficult to explain. Notably, response times are characterized by a fast-same effect whereby Same responses are faster than Different responses even though identical stimuli should be exhaustively processed to be accurate. Herein, we examine a little more than a quarter million response times (N = 255,744) obtained from 327 participants who participated in one of 14 variants of the task involving minor changes in the stimuli or their durations. We performed distribution fitting and analyzed estimated parameters stemming from the ex-Gaussian, lognormal, and Weibull distributions to infer the cognitive processing characteristics underlying this task. The results exclude serial processing of the stimuli and do not support dual-route processing. The fast-same effect appears only through a shift of the entire response time distributions, a feature impossible to detect solely with mean response time analyses. An attention-modulated process driven by entropy may be the most adequate model of the fast-same effect. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Prevalence of symptoms of depression, anxiety, insomnia, posttraumatic stress disorder, and psychological distress among populations affected by the COVID-19 pandemic: A systematic review and meta-analysis.

OBJECTIVE: We conducted a systematic review and meta-analysis to estimate the pooled prevalence of depression, anxiety, insomnia, PTSD, and Psychological distress (PD) related to COVID-19 among affected populations. METHODS: We searched articles in Medline, Embase, APA PsycInfo, CINAHL, Scopus, and Web of Science. Random-effects meta-analyses on the proportions of individuals with symptoms of depression, anxiety, insomnia, PTSD, and PD were generated and between-group differences for gender, healthcare workers (HCWs), and regions where studies were conducted. RESULTS: A total of 2189 articles were screened, 136 full-text articles were assessed for eligibility. Fifty-five peer-reviewed studies met inclusion criteria for the meta-analysis (N=189,159). The prevalence of depression (k=46) was 15.97% (95%CI, 13.24-19.13). The prevalence of anxiety (k=54) was 15.15% (95%CI, 12.29-18.54). The prevalence of insomnia (k=14) was 23.87% (95%CI, 15.74-34.48). The prevalence of PTSD (k=13) was 21.94% (95%CI, 9.37-43.31). Finally, the prevalence of psychological distress (k=19) was 13.29% (95%CI, 8.80-19.57). Between-group differences were only found in HCWs (z=2.69, p < 0.05) who had a higher prevalence of insomnia than others. CONCLUSIONS: Findings suggest that the short-term mental health consequences of COVID-19 are equally high across affected countries, and across gender. However, reports of insomnia are significantly higher among HCWs than the general population.

The cognitive architecture of processes responsible to assess similarity and clarity in a comparison task.

When asked to compare two stimuli, participants are on average faster to respond Same than Different, an effect coined the fast-same. The dual-process theory argues that information about similarity is processed in priority over any other type of information, causing the fast-same effect. We tested this serial architecture of cognitive processes using a double factorial paradigm, suitable for a Systems Factorial Technology (SFT) analysis. Twenty participants completed a task in which they compared two letters, which were varied on two dimensions: the similarity and the clarity of the letters. Their task was to indicate if the second letter was the Same as the second letter (ranging from identical and clear to similar and slightly blurry) or if it was Different (if the stimuli were either dissimilar or very blurry). The SFT results show that most participants processed the information in serial, but in a mixed order. In other words, for some trials, participants processed similarity first, and for some other trials, they processed clarity first. This implies that participant indeed processed information in serial in the comparison task, but that it does not cause the fast-same effect.

The fast-same effect of an exclusive-OR task.

Participants are faster to decide that two stimuli are identical than to decide that they are different. Opposing theories suggested that this fast-same effect is either due (a) to a response bias toward similarity or (b) to facilitation caused by the repetition of the stimuli attributes. Although both theories predict the fast-same effect in a conventional same-different task, they make distinct predictions for tasks in which response bias is removed. In such tasks, the bias theory predicts that the fast-same would disappear whereas the facilitation theory predicts that the fast-same would remain. We tested those hypotheses using a same-different task in which participants had to indicate if all the attributes of the stimuli were matching or all were mismatching by pressing one response key, or if some attributes were matching and some were mismatching, by pressing another response key. We call this an exclusive-OR same-different task. Results show that participants were much faster in the "all-matching" condition compared with the "all-mismatching" condition, therefore supporting the facilitation theory. A fit of the linear ballistic accumulator model to the observed data provide additional supports that the fast-same effect is not caused by bias, but by a faster accumulation rate of evidence in the "all-matching" condition. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Cognitive architecture and capacity of the cognitive system responsible for Same - Different judgments.

Participants tend to match identical pairs of stimuli faster than different pairs. Despite many endeavours to explain this fast-same effect, there is still no theoretical consensus. A potential reason for the lack of consensus is that the cognitive architecture and capacity underlying such phenomenon is assumed and not formally tested. For example, the dual-process approach suggests that Same responses arise from a parallel treatment, whereas Different responses arise from a serial treatment. It also suggests that in both conditions, the capacity of the process is unaffected by workload (unlimited capacity). Alternative approaches argue that the fast-same effect can be explained by parallel or coactive architectures with channels working in either limited or super capacity. In this study, we formally assess the architecture (three possibilities: serial, parallel and coactive) and the capacity (three possibilities: unlimited, limited and super-capacity) of the cognitive system in a Same-Different task using Systems Factorial Technology (SFT). We recruited twenty participants to perform a double-factorial task lasting four sessions. Because of the lack of effectiveness of the blurring manipulation, we cannot draw a strong conclusion about the cognitive architecture. As for the capacity, the results show that it is mostly limited for the majority of participants. However, between 300 and 500 ms, participants tend to have a much stronger processing capacity in the Same condition compared to the Different condition. This short but strong burst of activity for identical stimuli might explain the fast-same effect.

Sequential sampling models of same-different data and how they explain the fast-same effect.

There have been many empirical endeavors to explain the fact that participants correctly identify same stimuli faster than different stimuli. Despite a large body of literature, a conclusive and unanimous consensus to explain this effect is lacking. The present study offers a new perspective on the same-different task using best-fitting parametric values of 2 sequential sampling models (linear ballistic accumulator [LBA] and drift-diffusion model [DDM]) to evaluate the contribution of 3 theoretical concepts (starting point, accumulation rate, and base time) to the fast-same effect. Eighteen participants were recruited to perform 3 tasks in which they compared letter strings (a) in a normal setting, the control task; (b) with lower contrast, the contrast task; and (c) based on nominal identity, the case task. Both the LBA and the DDM suggests that participants have faster base time in the same condition compared with the different condition. They also suggest that the number of letters and the number of differences influence the accumulation rate. These results suggest that the cognitive processes do not accumulate information as efficiently when the workload is increased. Finally, the limited predictive power of the best-fitting models suggests that better theoretical grounds are needed to identify fundamental cognitive concepts underlying same-different judgments. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Faces elicit different scanning patterns depending on task demands.

Eye movements were recorded while participants discriminated upright and inverted faces that differed with respect to either configural or featural information. Two hypotheses were examined: (1) whether featural and configural information processing elicit different scanning patterns; (2) whether fixations on a specific region of the face dominate scanning patterns. Results from two experiments were compared to examine whether participants' prior knowledge of the kind of information that would be relevant for the task (i.e., configural vs featural) influences eye movements. In Experiment 1, featural and configural discrimination trials were presented in random order such that participants were unaware of the information that would be relevant on any given trial. In Experiment 2, featural and configural discrimination trials were blocked and participants were informed of the nature of the discriminations. The results of both experiments suggest that faces elicit different scanning patterns depending on task demands. When participants were unaware of the nature of the information relevant for the task at hand, face processing was dominated by attention to the eyes. When participants were aware that relational information was relevant, scanning was dominated by fixations to the center of the face. We conclude that faces elicit scanning strategies that are driven by task demands.