Can we Measure Individual Differences in Cognitive Measures Reliably via Smartphones? A Comparison of the Flanker Effect Across Device Types and Samples

Research deployed via the internet and administered via smartphones could have access to more diverse samples than lab-based research. Diverse samples could have relatively high variation in their traits and so yield relatively reliable measurements of individual differences in these traits. Cognitive tasks have been reported to yield relatively low reliabities (Hedge et al., 2018), which could potentially be addressed by smartphone-mediated administration in diverse samples. We formulate several criteria to determine whether a cognitive task is suitable for individual differences research on commodity smartphones: no very brief or precise stimulus timing, relative response times (RTs), a maximum of two response options, and a small number of graphical stimuli. The Flanker Task meets these criteria. We compared the reliability of individual differences in the Flanker Effect across samples and devices in a pre-registered study. We found no evidence that a more diverse sample yields higher reliabilities. We also found no evidence that commodity smartphones yield lower reliabilities than commodity laptops. Hence, diverse samples might not improve reliability above student samples, but smartphones may well measure individual differences with cognitive tasks reliably. Exploratively, we examined different reliability coefficients, split-half reliabilities, and the development of reliability estimates as a function of task length.

Attentional bias during emotional processing: Behavioral and electrophysiological evidence from an Emotional Flanker Task

Threatening stimuli seem to capture attention more swiftly than neutral stimuli. This attention bias has been observed under different experimental conditions and with different types of stimuli. It remains unclear whether this adaptive behaviour reflects the function of automatic or controlled attention mechanisms. Additionally, the spatiotemporal dynamics of its neural correlates are largely unknown. The present study investigates these issues using an Emotional Flanker Task synchronized with EEG recordings. A group of 32 healthy participants saw response-relevant images (emotional scenes from IAPS or line drawings of objects) flanked by response-irrelevant distracters (i.e., emotional scenes flanked by line drawings or vice versa). We assessed behavioural and ERP responses drawn from four task conditions (Threat-Central, Neutral-Central, Threat-Peripheral, and Neutral-Peripheral) and subjected these responses to repeated-measures ANOVA models. When presented as response-relevant targets, threatening images attracted faster and more accurate responses. They did not affect response accuracy to targets when presented as response-irrelevant flankers. However, response times were significantly slower when threatening images flanked objects than when neutral images were shown as flankers. This result replicated the well-known Emotional Flanker Effect. Behavioural responses to response-relevant threatening targets were accompanied by significant modulations of ERP activity across all time-windows and regions of interest and displayed some meaningful correlations. The Emotional Flanker Effect was accompanied by a modulation over parietal and central-parietal regions within a time-window between 550-690ms. Such a modulation suggests that the attentional disruption to targets caused by response-irrelevant threatening flankers appears to reflect less neural resources available, which are seemingly drawn away by distracting threatening flankers. The observed spatiotemporal dynamics seem to concur with understanding of the important adaptive role attributed to threat-related attention bias.

A bimodal extension of the Eriksen flanker task

The Eriksen flanker task is a traditional conflict paradigm for studying the influence of task-irrelevant information on the processing of task-relevant information. In this task, participants are asked to respond to a visual target item (e.g., a letter) that is flanked by task-irrelevant items (e.g., also letters). Responses are typically faster and more accurate when the task-irrelevant information is response-congruent with the visual target than when it is incongruent. Several researchers have attributed the starting point of this flanker effect to poor selective filtering at a perceptual level (e.g., spotlight models), which subsequently produces response competition at post-perceptual stages. The present study examined whether a flanker-like effect could also be established within a bimodal analog of the flanker task with auditory irrelevant letters and visual target letters, which must be processed along different processing routes. The results of two experiments revealed that a flanker-like effect is also present with bimodal stimuli. In contrast to the unimodal flanker task, however, the effect only emerged when flankers and targets shared the same letter name, but not when they were different letters mapped onto the same response. We conclude that the auditory flankers can influence the time needed to recognize visual targets but do not directly activate their associated responses.

Exploring an Emotional Basis of Cognitive Control in the Flanker Task

The emotional basis of cognitive control has been investigated in the flanker task with various procedures and materials across different studies. The present study examined the issue with the same flanker task but with different types of emotional stimuli and design. In seven experiments, the flanker effect and its sequential modulation according to the preceding trial type were assessed. Experiments 1 and 2 used affective pictures and emotional facial expressions as emotional stimuli, and positive and negative stimuli were intermixed. There was little evidence that emotional stimuli influenced cognitive control. Experiments 3 and 4 used the same affective pictures and facial expressions, but positive and negative stimuli were separated between different participant groups. Emotional stimuli reduced the flanker effect as well as its sequential modulation regardless of valence. Experiments 5 and 6 used affective pictures but manipulated arousal and valence of stimuli orthogonally The results did not replicate the reduced flanker effect or sequential modulation by valence, nor did they show consistent effects of arousal. Experiment 7 used a mood induction technique and showed that sequential modulation was positively correlated with valence rating (the higher the more positive) but was negatively correlated with arousal rating. These results are inconsistent with several previous findings and are difficult to reconcile within a single theoretical framework, confirming an elusive nature of the emotional basis of cognitive control in the flanker task.

Domain-general inhibition ability predicts the intensity of inhibition on non-target language in bilingual word production: An ERP study

This study investigated the predictive effects of executive functions on bilingual language control processes. We used a flanker task, a switching task and an n-back task to investigate inhibition, shifting, and updating, respectively. We adopted a cued language switching task to investigate the language control processes during bilingual word production. Results of linear mixed effects models showed that picture naming in switch trials was significantly slower and elicited larger stimulus-locked N2 and N400-like components. The results further showed that the flanker effect alone robustly predicted the variability of the N2 but not N400-like switch effects. These findings suggest that domain-general inhibition appears to predict the intensity of inhibition exerted on the lexical items in the non-target language during bilingual word production, but bilingual language control only partially overlaps with executive functions.

Modulating Proactive Cognitive Control by Reward: Differential Anticipatory Effects of Performance Contingent and Non-Contingent Rewards

The present study investigated the influences of two different forms of reward presentation in modulating cognitive control. In three experiments, participants performed a flanker task for which one-third of trials were precued for a chance of obtaining a reward (reward trials). In Experiment 1, a reward was provided if participants made the correct response on reward trials but a penalty was given if they made an incorrect response on these trials. The anticipation of this performance-contingent reward increased response speed and reduced the flanker effect but had little influence on the sequential modulation of the flanker effect after incompatible trials. In Experiment 2, participants obtained a reward randomly on two-thirds of the precued reward trials and were given a penalty on the remaining one-third, regardless of their performance. The anticipation of this non-contingent reward had little influence on the overall response speed or flanker effect but reduced the sequential modulation of the flanker effect after incompatible trials. Experiment 3 also used performance non-contingent rewards but participants were randomly penalized more often than they were rewarded; non-contingent penalty had little influence on the sequential modulation of the flanker effect. None of the three experiments showed a reliable influence of the actual acquisition of rewards on task performance. These results indicate anticipatory effects of performance contingent and non-contingent rewards on cognitive control with little evidence of aftereffects.

Modulating Proactive Cognitive Control by Reward: Differential Anticipatory Effects of Performance Contingent and Non-Contingent Rewards

The present study investigated the influences of two different forms of reward presentation in modulating cognitive control. In three experiments, participants performed a flanker task for which one-third of trials were precued for a chance of obtaining a reward (reward trials). In Experiment 1, a reward was provided if participants made the correct response on reward trials but a penalty was given if they made an incorrect response on these trials. The anticipation of this performance-contingent reward increased response speed and reduced the flanker effect but had little influence on the sequential modulation of the flanker effect after incompatible trials. In Experiment 2, participants obtained a reward randomly on two-thirds of the precued reward trials and were given a penalty on the remaining one-third, regardless of their performance. The anticipation of this non-contingent reward had little influence on the overall response speed or flanker effect but reduced the sequential modulation of the flanker effect after incompatible trials. Experiment 3 also used performance non-contingent rewards but participants were randomly penalized more often than they were rewarded; non-contingent penalty had little influence on the sequential modulation of the flanker effect. None of the three experiments showed a reliable influence of the actual acquisition of rewards on task performance. These results indicate anticipatory effects of performance contingent and non-contingent rewards on cognitive control with little evidence of aftereffects.