Paul Kelber

Conflict tasks often yield smaller mean congruency effects when relevant (target) and irrelevant (distractor) information is mostly incongruent rather than mostly congruent. While this proportion congruency effect may reflect proactive control adaptation, only a few previous studies have provided convincing evidence for proactive control adaptation when ruling out contingency learning and reactive (item-specific) control adaptation. In this study, we present further evidence for proactive control adaptation (as reflected in proportion congruency effects and asymmetrical list-shifting effects in contingency-controlled diagnostic items) across three experiments (each N = 100 participants) using manual counting Stroop tasks (Experiment 1: number words as distractors; Experiment 2: Arabic numerals as distractors; Experiment 3: number words and Arabic numerals as inducer and diagnostic items or vice versa). To better understand the processes underlying proactive control adaptation, we conducted fine-grained distributional analyses (delta functions) and model-based analyses (diffusion model for conflict tasks). These analyses suggest that proactive control adaptation in manual counting Stroop tasks mainly reflects adjustments in the strength of distractor suppression rather than in the timing of distractor suppression, the strength of target amplification, or response caution. Additional distributional and diffusion model reanalyses of the data by Spinelli and Lupker (2023, Experiments 1-3) revealed a similar pattern in vocal color Stroop tasks. In conclusion, the present study provides new evidence for proactive control adaptation in manual counting Stroop tasks and indicates that proactive control adaptation mainly reflects adjustments in the strength of distractor suppression in both manual and vocal Stroop tasks. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

A growing body of psychophysical research suggests that the discrimination of successive stimuli involves more than taking the difference between their sensation magnitudes, challenging traditional difference models. Two elaborated theories assume that each sensation magnitude is weighted by its reference level (sensation weighting model) or that the second sensation magnitude is compared to a dynamically updated internal reference, in which the first sensation magnitude gravitates towards the previous reference level (internal reference model). Whereas both models can explain higher discrimination sensitivity when the standard precedes the comparison (negative Type B effect), only the sensation weighting model can account for higher discrimination sensitivity when the standard follows the comparison (positive Type B effect). Most previous studies reported negative Type B effects, while some positive Type B effects have also been reported, especially for duration discrimination with short stimulus durations and/or short inter-stimulus intervals combined with adaptive-staircase procedures. The present study systematically searched for positive Type B effects in visual duration discrimination by orthogonally varying stimulus duration (80 vs. 500 ms standard), inter-stimulus interval (200 vs. 900 ms), and stimulus type (filled vs. empty intervals) across four experiments using the method of constant stimuli. Type B effects were consistently negative across all experimental conditions and analysis methods. The absence of positive Type B effects is consistent with the internal reference model and casts doubt on whether the additional flexibility in the sensation weighting model is needed to explain visual duration discrimination sensitivity.

In Egon Brunswik’s theory of probabilistic functionalism, human prediction is conceptualized as an inductive inference process, in which cues are utilized as a lens to predict the probabilistically associated criterion in the environment. Dynamic cognitive adjustment, driven by the uncertainty of the individual and the substitutability of the environment, is based on vicarious functioning, the principle of learning from the frequency of co-occurrences. However, previous models of vicarious functioning, the multiple-regression lens and the fast-and-frugal lens, fail to explain how the individual reduces uncertainty while learning ecological cue validities. We therefore developed a diffusion lens model of vicarious functioning that captures dynamic cognitive adjustment to environments with multiple probabilistic and substitutable cues. A superstatistics approach allowed us to account for uncertainty reduction over time by an increasing sensitivity of the drift rate to the ecological validity of the cues. Additionally, the non-decision time is assumed to increase linearly with the number of presented cues to account for cue substitutability in the environment. The resulting model was validated by successfully fitting it to response time and choice data previously collected across multiple-cue probability learning tasks in diverse environments and scenarios. This suggests that the diffusion lens model can explain cognitive adjustment from an initial absence of knowledge to a near-perfect approximation of the probabilistic environment.

Independent-channels models of temporal-order and simultaneity perception assume that a central (amodal) timing mechanism compares the arrival times of incoming sensory signals independently of peripheral (modal) events. This implies that peripheral latencies and central threshold are additive. The present study tested whether the central threshold is invariant to intramodal versus intermodal stimulation (Experiment 1) and strong versus weak intermodal stimulation (Experiment 2). The central threshold was isolated via the distance between the two psychometric functions in the ternary-response task, which does not depend on peripheral latencies under the additivity assumption. In Experiment 1, the central threshold was estimated to be significantly higher for intermodal stimuli (light and sound) than for intramodal stimuli (two lights) for all subjects across the entire practice curve (20 one-hour sessions) and also at the group level. In Experiment 2, the estimates of the central threshold were significantly higher for weak intermodal stimuli (dim light and soft sound) than for strong ones (bright light and loud sound) for most subjects and at the group level. These violations of threshold invariance in both experiments provide converging evidence against the independence of peripheral latencies and central threshold, and thus challenge the dominant class of theoretical models of temporal-order and simultaneity perception.

The theory that the temporal flow of events is perceived as a succession of discrete moments has long fascinated psychologists and neuroscientists. Perceptual-moment theories generally hold that events appear successive and in temporal order only if their sensory messages arrive in different moments; otherwise, events appear simultaneous and in no temporal order. Three varieties of perceptual-moment theory assume that moments are disjunct and autonomous (autonomous-moments theory), that the arrival of a sensory message triggers a stream of disjunct moments (triggered-moments theory), or that an autonomous moment moves continuously (moving-moment theory). Previous psychophysical analyses of the moment concept did not respect the neural noise inherent to the brain by prohibiting any fluctuation in the moment duration or even in the transmission times. We present generalized models rooted in the three varieties of perceptual-moment theory, which allow the separation of latency noise and moment-duration noise under various plausible distributional assumptions. Our simulations demonstrate that only the autonomous-moments model does not produce central plateaus, which are often observed in simultaneity judgments and sometimes in temporal-order judgments. When fitting 18 perceptual-moment models to three simultaneity-judgment data sets and three temporal-order judgment data sets, the autonomous-moments model provides a worse fit compared to the triggered-moments and moving-moment models, consistently across both tasks and all plausible distributional assumptions. In conclusion, the rigorous psychophysical analysis suggests that even under relaxed assumptions, the classic autonomous-moments theory is unable to explain even the simplest temporal judgments. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

We are continually required to exercise cognitive control in order to separate relevant and irrelevant information. Previous studies have produced mixed results as to whether cognitive control declines across adulthood and improves with practice. Moreover, little is known about the influences of aging and practice on the automatic and controlled processes underlying performance in conflict situations. This calls for analyses of extensive data using process models for conflict tasks, akin to earlier drift-diffusion model analyses of performance in cognitive nonconflict tasks. Thus, to understand how aging and practice influence cognitive control at the process level, we analyzed a large-scale data set (1,800 participants aged 21-80 years completing 60 blocklike online games of an arrow-based Eriksen flanker task). At the coarse-grained level of mean response times, the congruency effect increased across adulthood and decreased with practice following an initial increase. The finer-grained distributional response time and error rate data were closely fitted by the diffusion model for conflict tasks, which captures the dynamic interplay of automatic and controlled processing. Best-fitting parameter values revealed multiple, partially counteracting influences of aging and practice: Aging across adulthood slowed down both controlled and automatic processing (besides slowing down nondecisional processes and increasing decision caution). By contrast, practice selectively speeded up controlled processing (besides speeding up nondecisional processes and decreasing decision caution). Taken together, these findings suggest that aging and practice primarily alter the speed of controlled (aging and practice) and automatic processing (aging), rather than causing inhibitory adjustments in the strength of automatic processing. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The perception of temporal order or simultaneity of stimuli is almost always explained in terms of independent-channels models, such as perceptual-moment, triggered-moment, and attention-switching models. Independent-channels models generally posit that stimuli are processed in separate peripheral channels and that their arrival-time difference at a central location is translated into an internal state of order (simultaneity) if it reaches (misses) a certain threshold. Non-monotonic and non-parallel psychometric functions in a ternary-response task provided critical evidence against a wide range of independent-channels models. However, two independent-channels models have been introduced in the last decades that can account for such shapes by considering misreports of internal states (response-error model) or by assuming that simultaneity and order judgments rely on distinct sensory and decisional processes (two-stage model). Based on previous ideas, we also consider a two-threshold model, according to which the same arrival-time difference may need to reach a higher threshold for order detection than for successiveness detection. All three models were fitted to various data sets collected over a period of more than a century. The two-threshold model provided the best balance between goodness of fit and parsimony. This preference for the two-threshold model over the two-stage model and the response-error model aligns well with several lines of evidence from cognitive modeling, psychophysics, mental chronometry, and psychophysiology. We conclude that the seemingly deviant shapes of psychometric functions can be explained within the framework of independent-channels models in a simpler way than previously assumed.