Filip Van Opstal

Mind wandering – a spontaneous shift in attention away from a task – has been consistentlyassociated with impaired cognitive task performance, often attributed to disruptions inexecutive functioning. In this study, we conducted three experiments to replicate and extendprevious work (Kam & Handy, 2014) by examining how mind wandering interacts with threecore executive functions: Inhibition (Experiment 1: Sustained Attention to Response Task, n= 54), updating (Experiment 2: Random n-back Task, n = 52) and shifting (Experiment 3:Number-Letter Task, n = 54). If mind wandering is closely related to executive functioning, itwas expected that mind wandering would impair performance on trials requiring thesefunctions, reflected in lower accuracy and increased reaction time variability. Our findingsdid not confirm this: Mind wandering was associated with a general negative effect onperformance, rather than specifically impairing executive functioning. Accuracy was loweron executive than non-executive trials in the inhibition and shifting tasks, but these effectswere not attenuated by mind wandering. In the updating task, where executive and non-executive trials were matched in difficulty, mind wandering reduced accuracy in bothexecutive and non-executive trials. Variability in reaction time was found to be higher duringmind wandering in the inhibition and updating tasks, with evidence against such an effect inthe shifting task. These findings suggest that the observed performance decrements may bemore closely tied to task demands than to executive functions per se.

Recent studies using the variable choice paradigm for a word-association learning task suggest that reward prediction errors (RPEs) enhance one-shot declarative learning. However, these studies may confound true associative learning with an “RPE bias,” where RPE items become more salient or fluent and are therefore chosen during recognition. This study tested whether such a bias exists and whether RPEs genuinely strengthen word-pair learning. Across three sessions, participants (n = 48) completed a modified version of the variable choice paradigm in which English-Swahili word pairs were learned under either RPE or no-RPE conditions. Results provided moderate evidence against an RPE bias: RPE words were not more likely to be selected when incorrect. In contrast, correctness strongly predicted choice, and correct translations associated with RPEs were moderately more likely to be chosen than correct translations without RPEs, indicating a true learning benefit. Confidence analyses mirrored this pattern, showing strong evidence against an effect of RPE bias but extreme evidence for an effect of correctness. Furthermore, confidence was much higher for correct translations with RPE compared to correct translations without RPE. Together, these findings demonstrate that RPEs improve associative memory without producing choice biases. Our results validate previous conclusions about RPE-driven declarative learning benefits.

Recent studies using the variable choice paradigm for word-association learning task suggest that reward prediction errors (RPEs) enhance one-shot declarative learning. However, these studies may confound true associative learning with an “RPE bias,” where high-RPE items become more salient or fluent and are therefore chosen during recognition. This study tested whether such a bias exists and whether RPEs genuinely strengthen word-pair learning. Across three sessions, participants (N = 48) completed a modified version of the variable choice paradigm in which English-Swahili word pairs were learned under either high-RPE or no-RPE conditions. Results provided moderate evidence against an RPE bias: high-RPE words were not more likely to be selected when incorrect. In contrast, correctness strongly predicted choice, and correct translations associated with high RPEs were moderately more likely to be chosen than correct translations without RPEs, indicating a true learning benefit. Confidence analyses mirrored this pattern, showing clear effects of correctness but inconclusive effects of RPE. Together, these findings demonstrate that RPEs improve associative memory without producing choice biases. Our results validate previous conclusions about RPE-driven declarative learning benefits.

Stockart et al. provide some methodological recommendations to guide future research on unconscious perceptual and cognitive processes. Here, I explain why several of these recommendations are unlikely to reduce existing ambiguities and provide insufficient guidance for their operationalization, and I argue that future research may benefit more from adopting an alternative research strategy.

Multisensory integration enhances perceptual performance, often resulting in more accurate and efficient decision-making compared to unisensory processing. In contrast, impulsive behavior is associated with decreased decision accuracy and adverse outcomes. However, the influence of impulsivity on multisensory integration (MSI) remains poorly understood. This study investigated this relationship in a sample of 40 participants, including 10 individuals diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD) or Disruptive Behavior Disorders (DBDs), both of which are characterized by elevated impulsivity. Participants had to discriminate between two visual gratings, and/or two sounds presented to the right and left ear based on respectively contrast and loudness in a two-alternative forced-choice task. Results show similar task performance across participants. Performance accuracies were highest on audiovisual trials and participants responded fastest on auditory trials, independent of impulsivity levels. Examining the timescale of evidence weighting revealed that early sensory information contributed most to decisions, with dynamic dominance switching between visual and auditory modalities. We found no evidence that the temporal dynamics were affected by impulsivity. These findings suggest that impulsivity and impulsivity related behaviours do not significantly affect MSI during our task and that sensory processing mechanisms remain robust against individual impulsivity levels.

Multisensory integration (MSI) allows the brain to combine information from different sensory modalities to form a coherent perception of the environment. Externalizing disorders with impulsivity as a key symptom such as Attention-Deficit/Hyperactivity Disorder (ADHD) have been associated with altered sensory processing and decision-making. This study investigated the relationship between impulsivity and impulsivity related behaviours, and multisensory integration. Participants had to discriminate between two visual gratings, and/or two sounds presented to the right and left ear based on respectively contrast and loudness in a two-alternative forced-choice task. The study included 44 participants, 13 of whom were diagnosed with ADHD or Disruptive Behaviour Disorders. Results show similar task performance across participants. Performance accuracies were highest on audiovisual trials and participants responded fastest on auditory trials, independent of impulsivity levels. Examining the timescale of evidence weighting revealed that early sensory information contributed most to decisions, with dynamic dominance switching between visual and auditory modalities. We found no evidence that the temporal dynamics were affected by impulsivity. These findings suggest that impulsivity and impulsivity related behaviours do not significantly affect MSI during our task and that sensory processing mechanisms remain robust against individual impulsivity levels.

People differ in their optimal time of day to perform a cognitive task: Morning people (“larks”) perform better in the morning compared to the evening, and the reversed is true for evening people (“owls”). This synchrony effect has been observed for executive functions, such as inhibitory control. For example, participants performing the Sustained Attention to Response Task (SART) make more commission errors at their non-optimal time of day. Because mind-wandering (MW) has been related to the executive system, we here investigated a synchrony effect in the frequency of MW. After determining the participants’ chronotype (n = 130), they completed an online version of the SART twice, once in the morning and once in the evening. MW was subjectively measured using a probe-caught method. Results showed that “larks” mind-wandered more often in the evening than the morning session. In contrast, “owls” showed the opposite profile. Objective markers for MW (i.e., accuracy and reaction time coefficient of variance) confirmed these results. Furthermore, in line with earlier suggestions, the frequency of MW was also directly related to the number of hours slept the night before the experiment, and an overall higher frequency of MW was observed for evening chronotypes. The results of this study provide clear evidence for the relation between sleep-related factors and MW, and raises the importance of accounting for chronotype differences when scheduling work and academic activities.

Perceptual decision-making in a dynamic environment requires two integration processes: integration of sensory evidence from multiple modalities to form a coherent representation of the environment, and integration of evidence across time to accurately make a decision. Only recently studies started to unravel how evidence from two modalities is accumulated across time to form a perceptual decision. One important question is whether information from individual senses contributes equally to multisensory decisions. We designed a new psychophysical task that measures how visual and auditory evidence is weighted across time. Participants were asked to discriminate between two visual gratings, and/or two sounds presented to the right and left ear based on respectively contrast and loudness. We varied the evidence, i.e., the contrast of the gratings and amplitude of the sound, over time. Results showed a significant increase in performance accuracy on multisensory trials compared to unisensory trials, indicating that discriminating between two sources is improved when multisensory information is available. Furthermore, we found that early evidence contributed most to sensory decisions. Weighting of unisensory information during audiovisual decision-making dynamically changed over time. A first epoch was characterized by both visual and auditory weighting, during the second epoch vision dominated and the third epoch finalized the weighting profile with auditory dominance. Our results suggest that during our task multisensory improvement is generated by a mechanism that requires cross-modal interactions but also dynamically evokes dominance switching.