Tracking continuities in the flanker task: From continuous flow to movement trajectories

The relationship between acute aerobic exercise and inhibitory control in college students: The impact of physical and cognitive engagement

OBJECTIVE

Evidence suggests that acute exercise is an effective way for improving inhibition control, however, the effect of different types of Acute Aerobic Exercise and Inhibitory Control (IC) remains unclear.

METHOD

Using a crossover design, 25 participants (M = 20.20year, SD=0.91) completed 20 min of interventions at 1) moderate intensity exercise, 2) moderate intensity exercise with high cognitive demand (high cognitive-demand exercise), 3) moderate intensity exercise with high physical demand (high physical-demand exercise), and 4) rest condition (low physical and cognitive demand) in a counterbalanced way. Flanker task was completed before and after each intervention to evaluate their inhibitory control ability.

RESULTS

The four interventions significantly reduce reaction times for both congruent and incongruent trials with Flanker task (all P < 0.05). Compared to acute moderate intensity exercise, high physical-demand exercise induced a greater reduction in reaction times for both trial types, whereas high cognitive-demand exercise led to faster reaction times in incongruent trials.

CONCLUSION

Although each intervention effectively enhanced inhibitory control, the exercise demanding high cognitive and physical effort contributed to a more pronounced improvement in inhibitory control performance. This indicates that both increased physical and cognitive engagement can significantly improve the level of inhibitory control in young adults.

Exploring the impact of stimulus-stimulus and stimulus-response conflicts on computer mouse trajectories: continuous flow of information from stimulus encoding to response preparation to motor action

In recent years, mouse tracking (designing experiments in which participants provide responses via dynamic computer mouse movements) has enjoyed increasing experience in experimental psychology. Mouse-tracking studies typically involve some form of stimulus-response (S-R) conflict, and S-R effects emerge in movement trajectories (as well as in latencies). By contrast, it is currently unclear how stimulus-stimulus (S-S) compatibility affects movements. Here, we used a spatial arrow task which allowed us to generate S-R and S-S effects within the same experiment. Experiment 1 clarified in a key press experiment that this manipulation generates clear S-S and S-R effects in latencies. More critically, Experiment 2 demonstrated that both types of conflict impact mouse trajectories with incompatibility emerging as increased 'curvature' of responses when compared to congruent responses. We argue that these results are best explained via the assumption of 'continuous flow' of information, from stimulus encoding to response preparation and finally into motor action. By contrast, the S-S effect on trajectories contradicts the notion that processing is 'thresholded' between stimulus encoding and response preparation.

Effects of conflict in cognitive control: Evidence from mouse tracking

It has long been debated whether the "congruency sequence effect (CSE)" in conflict tasks such as Flanker could reflect adaptive control. The current study used "mouse tracking" to tackle the issue in a combination of three conflict tasks (i.e., Flanker, Simon, and Spatial Stroop tasks). Congruency effects from previous and current trials emerged in latencies as well as curvature of movement trajectories in all three tasks. Critically, movement initiation times were affected only by congruency on previous but not on current trials. A further analysis showed that even when initiation time on the previous trials was taken into account, a subtle but highly significant effect of conflict arising from trial N-1 on initiation times remained. Although not necessarily implying "conflict adaptation," i.e., a dynamic up- and downregulation of cognitive control in response to a recent conflict, our finding indicates a specific sensitivity to the presence or absence of recent "conflict" in the cognitive environment.

Moving beyond response times with accessible measures of manual dynamics

Button-press measures of response time (RT) and accuracy have long served a central role in psychological research. However, RT and accuracy provide limited insight into how cognitive processes unfold over time. To address this limitation, researchers have used hand-tracking techniques to investigate how cognitive processes unfold over the course of a response, are modulated by recent experience, and function across the lifespan. Despite the efficacy of these techniques for investigating a wide range of psychological phenomena, widespread adoption of hand-tracking techniques within the field is hindered by a range of factors, including equipment costs and the use of specialized software. Here, we demonstrate that the behavioral dynamics previously observed with specialized motion-tracking equipment in an Eriksen flanker task can be captured with an affordable, portable, and easy-to-assemble response box. Six-to-eight-year-olds and adults (N = 90) completed a computerized version of the flanker task by pressing and holding a central button until a stimulus array appeared. Participants then responded by releasing the central button and reaching to press one of two response buttons. This method allowed RT to be separated into initiation time (when the central button was released) and movement time (time elapsed between initiation and completion of the response). Consistent with previous research using motion-tracking techniques, initiation times and movement times revealed distinct patterns of effects across trials and between age groups, indicating that the method used in the current study presents a simple solution for researchers from across the psychological and brain sciences looking to move beyond RTs.

Control of Attention in Rhesus Monkeys Measured Using a Flanker Task

At least three processes determine whether information we encounter is attended to or ignored. First, attentional capture occurs when attention is drawn automatically by "bottom up" processes, to distinctive, salient, rewarding, or unexpected stimuli when they enter our sensory field. Second, "top down" attentional control can direct cognitive processing towards goal-relevant targets. Third, selection history, operates through repeated exposure to a stimulus, particularly when associated with reward. Attentional control is measured using tasks that require subjects to selectively attend to goal-relevant stimuli in the face of distractions. In the Eriksen flanker task, human participants report which direction a centrally placed arrow is facing, while ignoring "flanking" arrows that may point in the opposite direction. Attentional control is evident to the extent that performance reflects only the direction of the central arrow. We describe four experiments in which we systematically assessed attentional control in rhesus monkeys using a flanker task. In Experiment 1, monkeys responded according to the identity of a central target, and accuracy and latency varied systematically with manipulations of flanking stimuli, validating our adaptation of the Eriksen flanker task. We then tested for converging evidence of attentional control across three experiments in which flanker performance was modulated by the distance separating targets from flankers (Experiment 2), luminance differences (Experiment 3), and differences in associative value (Experiment 4). The approach described is a new and reliable measure of attentional control in rhesus monkeys that can be applied to a wide range of situations with freely behaving animals.

Theta but not beta activity is modulated by freedom of choice during action selection

Large-scale neurophysiological markers of action competition have been almost exclusively investigated in the context of instructed choices, hence it remains unclear whether these markers also apply to free choices. This study aimed to compare the specific brain dynamics underlying instructed and free decisions. Electroencephalography (EEG) was recorded while 31 participants performed a target selection task; the choice relied either on stimulus-response mappings (instructed) or on participants' preferences (free). Choice difficulty was increased by introducing distractors in the informative stimulus in instructed choices, and by presenting targets with similar motor costs in free choices. Results revealed that increased decision difficulty was associated with higher reaction times (RTs) in instructed choices and greater choice uncertainty in free choices. Midfrontal EEG theta (4-8 Hz) power increased with difficulty in instructed choices, but not in free choices. Although sensorimotor beta (15-30 Hz) power was correlated with RTs, it was not significantly influenced by choice context or difficulty. These results suggest that midfrontal theta power may specifically increase with difficulty in externally-driven choices, whereas sensorimotor beta power may be predictive of RTs in both externally- and internally-driven choices.

The role of valence in word processing: Evidence from lexical decision and emotional Stroop tasks

It is widely accepted that the valence of a word (neutral, positive, or negative) influences lexical processing, yet data from the commonly used lexical decision and emotional Stroop tasks has yielded inconsistent findings regarding the direction of this influence. One critical obstacle to investigating the independent effects of valence is the matching of emotional and neutral stimuli on the lexical, sublexical, and conceptual characteristics known to influence word recognition. The second obstacle is that the cognitive processes which lead to a lexical decision and a colour naming response are unobservable from the response latency measures typically gathered. The present study compiled a set of neutral, positive, and negative words matched triplet-wise on 26 influential characteristics. The novel "mouse tracking" technique was used to analyse the development of responses to these materials in variants of the lexical decision and emotional Stroop task. A conventional key-press emotional Stroop task is also reported. Results revealed a significant processing advantage for positive words over negative and neutral words in the lexical decision task, whereas valence alone did not produce any significant effects in the emotional Stroop task. The discrepancy between the effects of valence across these different tasks is discussed. We also suggest that previous conflicting findings may be confounded by unmatched emotional and neutral stimuli, thus inflating the potential effects of valence.

Revealing the effects of temporal orienting of attention on response conflict using continuous movements

Orienting attention in time enables us to prepare for forthcoming perception and action (e.g., estimating the duration of a yellow traffic light when driving). While temporal orienting can facilitate performance on simple tasks, its influence on complex tasks involving response conflict is unclear. Here, we adapted the flanker paradigm to a choice-reaching task where participants used a computer mouse to reach to the left or right side of the screen, as indicated by the central arrow presented with either the congruent or incongruent flankers. We assessed the effects of temporal orienting by manipulating goal-driven temporal expectation (using probabilistic variations in target timing) and stimulus-driven temporal priming (using sequential repetitions versus switches in target timing). We tested how temporal orienting influenced the dynamics of response conflict resolution. Recent choice-reaching studies have indicated that under response conflict, delayed movement initiation captures the response threshold adjustment process, whereas increased curvature toward the incorrect response captures the degree of coactivation of the response alternatives during the controlled response selection process. Both temporal expectation and priming reduced the initiation latency regardless of response conflict, suggesting that both lowered response thresholds independently of response conflict. Notably, temporal expectation, but not temporal priming, increased the curvature toward the incorrect response on incongruent trials. These results suggest that temporal orienting generally increases motor preparedness, but goal-driven temporal orienting particularly interferes with response conflict resolution, likely through its influence on response thresholds. Overall, our study highlights the interplay between temporal orienting and cognitive control in goal-directed action.

A beginning quantitative taxonomy of cognitive activation systems and application to continuous flow processes

Much progress has been made in the investigation of perceptual, cognitive, and action mechanisms under the assumption that when one subprocess precedes another, the first one starts and finishes before the other begins. We call such processes "Dondersian" after the Dutch physiologist who first formulated this concept. Serial systems obey this precept (e.g., Townsend, 1974). However, most dynamic systems in nature do not: instead, each subprocess communicates its state to its immediate successors continuously. Although the mathematics for physical systems has received extensive treatment over the last three centuries, applications to human cognition have been exiguous. Therefore, the pioneering papers by Charles Eriksen and colleagues on continuous flow dynamics (e.g., Eriksen & Schulz, Perception & Psychophysics, 25, 249-263, 1979; Coles et al.,, Journal of Experimental Psychology: Human Perception and Performance, 11(5), 529, 1985) must be viewed as truly revolutionary. Surprisingly, there has been almost no advancement on this front since. With the goal of bringing this theme back into the scientific consciousness and extending and deepening our understanding of such systems, we develop a taxonomy that emphasizes the fundamental characteristics of continuous flow dynamics. Subsequently, we complexify the treated systems in such a way as to illustrate the popular cascade model (Ashby, Psychological Review, 89, 599-607, 1982; McClelland, Psychological Review, 86, 287-330, 1979) and use it to simulate the classic findings of Eriksen and colleagues (Eriksen & Hoffman, Perception & Psychophysics, 12(2), 201-204, 1972).