Voluntary task switching is affected by modality compatibility and preparation.

Cognitive task control can be examined in task-switching studies. Performance costs in task switches are usually smaller with compatible stimulus-response modality mappings (visual-manual and auditory-vocal) than with incompatible mappings (visual-vocal and auditory-manual). Modality compatibility describes the modality match of sensory input and of the anticipated response effect (e.g., vocal responses produce auditory effects, so that auditory stimuli are modality-compatible with vocal responses). Fintor et al. (Psychological Research, 84(2), 380-388, 2020) found that modality compatibility also biased task choice rates in voluntary task switching (VTS). In that study, in each trial participants were presented with a visual or auditory spatial stimulus and were free to choose the response modality (manual vs. vocal). In this free-choice task, participants showed a bias to create more modality-compatible than -incompatible mappings. In the present study, we assessed the generality of Fintor et al.'s (2020) findings, using verbal rather than spatial stimuli, and more complex tasks, featuring an increased number of stimulus-response alternatives. Experiment 1 replicated the task-choice bias to preferentially create modality-compatible mappings. We also found a bias to repeat the response modality just performed, and a bias to repeat entire stimulus-response modality mappings. In Experiment 2, we manipulated the response-stimulus interval (RSI) to examine whether more time for proactive cognitive control would help resolve modality-specific crosstalk in this free-choice paradigm. Long RSIs led to a decreased response-modality repetition bias and mapping repetition bias, but the modality-compatibility bias was unaffected. Together, the findings suggest that modality-specific priming of response modality influences task choice.

Time-based task expectancy: perceptual task indicator expectancy or expectancy of post-perceptual task components?

The temporal predictability of upcoming events plays a crucial role in the adjustment of anticipatory cognitive control in multitasking. Previous research has demonstrated that task switching performance improved if tasks were validly predictable by a pre-target interval. Hence, far, the underlying cognitive processes of time-based task expectancy in task switching have not been clearly defined. The present study investigated whether the effect of time-based expectancy is due to expectancy of post-perceptual task components or rather due to facilitation of perceptual visual processing of the coloured task indicator. Participants performed two numeric judgment tasks (parity vs. magnitude), which were each indicated by two different colours. Each task was either more or less frequently preceded by one of two intervals (500 ms or 1500 ms). Tasks were indicated either by colours that were each more frequently (or in Exp. 1 also less frequently) paired with the interval or by colours that were equally frequent for each interval. Participants only responded faster when colour and task were predictable by time (expected colour), not when the task alone was predictable (neutral colour). Hence, our results speak in favour of perceptual time-based task indicator expectancy being the underlying cognitive mechanism of time-based expectancy in the task switching paradigm.

Modality compatibility biases voluntary choice of response modality in task switching.

The term modality compatibility refers to the similarity between stimulus modality and the modality of response-related sensory consequences (e.g., vocal responses produce auditory effects). The previous results showed smaller task-switching costs when participants switched between modality compatible tasks (auditory-vocal and visual-manual) compared to switching between modality incompatible tasks (auditory-manual and visual-vocal). In the present study using a voluntary task-switching paradigm (VTS), participants chose the response modality (vocal or manual) to indicate the location of either a visual or an auditory stimulus. We examined whether free task choices were biased by modality compatibility, so that modality compatible tasks are preferred in VTS. The choice probability analysis indicated that participants tended to choose the response modality that is compatible to the stimulus modality. However, participants did not show a preference to repeat a stimulus-response (S-R) modality mapping, but to switch between modality compatibility (i.e., from S-R modality compatible mapping to S-R modality incompatible mapping and vice versa). More interestingly, even though participants freely chose the response modality, modality compatibility still influenced task-switching costs, showing larger costs with modality incompatible mappings. The finding that modality compatibility influenced choice behaviour suggests components of both top-down control and bottom-up effects of selecting a response modality for different stimulus modalities.

Task switching in autism: An EEG study on intentions and actions.

One of the main symptoms of Autism Spectrum Conditions (ASC) is experiencing cognitive inflexibility when adjustments of behaviour are required. While this so-called behavioural rigidity is broadly recognised in ASC, finding evidence for the underlying neurocognitive mechanisms remains challenging. In this electroencephalographic (EEG) study, participants with ASC and matched controls were instructed to choose between two cognitive tasks in each trial, and to respond to the subsequently presented target stimulus according to their task choice. While doing so, we tracked the frontally distributed contingent negative variation (CNV) during the task preparation interval as a measure of intentional control, and the posteriorly measured P3 during the task execution interval to monitor the translation of intentions into actions. The results support the notion of intentional control difficulties in ASC, where the CNV was attenuated in the ASC group compared to the control group. Furthermore, the CNV was differentiated between the tasks and transition types in the control group only, suggesting that the ASC group was less fine-tuning the required amount of intentional control to contextual circumstances. In contrast, the P3 showed no significant differences between the groups. Together, these findings highlight the importance of intentional control mechanisms as a crucial future route for a better understanding of cognitive flexibility and behavioural rigidity in ASC.

Cognitive structure, flexibility, and plasticity in human multitasking-An integrative review of dual-task and task-switching research.

Numerous studies showed decreased performance in situations that require multiple tasks or actions relative to appropriate control conditions. Because humans often engage in such multitasking activities, it is important to understand how multitasking affects performance. In the present article, we argue that research on dual-task interference and sequential task switching has proceeded largely separately using different experimental paradigms and methodology. In our article we aim at organizing this complex set of research in terms of three complementary research perspectives on human multitasking. One perspective refers to structural accounts in terms of cognitive bottlenecks (i.e., critical processing stages). A second perspective refers to cognitive flexibility in terms of the underlying cognitive control processes. A third perspective emphasizes cognitive plasticity in terms of the influence of practice on human multitasking abilities. With our review article we aimed at highlighting the value of an integrative position that goes beyond isolated consideration of a single theoretical research perspective and that broadens the focus from single experimental paradigms (dual task and task switching) to favor instead a view that emphasizes the fundamental similarity of the underlying cognitive mechanisms across multitasking paradigms. (PsycINFO Database Record

Multitasking as a choice: a perspective.

Performance decrements in multitasking have been explained by limitations in cognitive capacity, either modelled as static structural bottlenecks or as the scarcity of overall cognitive resources that prevent humans, or at least restrict them, from processing two tasks at the same time. However, recent research has shown that individual differences, flexible resource allocation, and prioritization of tasks cannot be fully explained by these accounts. We argue that understanding human multitasking as a choice and examining multitasking performance from the perspective of judgment and decision-making (JDM), may complement current dual-task theories. We outline two prominent theories from the area of JDM, namely Simple Heuristics and the Decision Field Theory, and adapt these theories to multitasking research. Here, we explain how computational modelling techniques and decision-making parameters used in JDM may provide a benefit to understanding multitasking costs and argue that these techniques and parameters have the potential to predict multitasking behavior in general, and also individual differences in behavior. Finally, we present the one-reason choice metaphor to explain a flexible use of limited capacity as well as changes in serial and parallel task processing. Based on this newly combined approach, we outline a concrete interdisciplinary future research program that we think will help to further develop multitasking research.

Task intentions and their implementation into actions: cognitive control from adolescence to middle adulthood.

Cognitive control processes involved in human multitasking arise, mature, and decline across age. This study investigated how age modulates cognitive control at two different levels: the level of task intentions and the level of the implementation of intentions into the corresponding actions. We were particularly interested in specifying maturation of voluntary task choice (intentions) and task-switching execution (their implementations) between adolescence and middle adulthood. Seventy-four participants were assigned to one of the four age groups (adolescents, 12-17 years; emerging adults, 18-22 years; young adults, 23-27 years; middle-aged adults, 28-56 years). Participants chose between two simple cognitive tasks at the beginning of each trial before pressing a spacebar to indicate that the task choice was made. Next, a stimulus was presented in one of the three adjacent boxes, with participants identifying either the location or the shape of the stimulus, depending on their task choice. This voluntary task-switching paradigm allowed us to investigate the intentional component (task choice) separately from its implementation (task execution). Although all participants showed a tendency to repeat tasks more often than switching between them, this repetition bias was significantly stronger in adolescents than in any adult group. Furthermore, participants generally responded slower after task switches than after task repetitions. This switch cost was similar across tasks in the two younger groups but larger for the shape than the location task in the two older groups. Together, our results demonstrate that both task intentions and their implementation into actions differ across age in quite specific ways.

Predictability of action sub-steps modulates motor system activation during the observation of goal-directed actions.

Action perception and execution are linked in the human motor system, and researchers have proposed that this action-observation matching system underlies our ability to predict observed behavior. If the motor system is indeed involved in the generation of action predictions, activation should be modulated by the degree of predictability of an observed action. This study used EEG and eye-tracking to investigate whether and how predictability of an observed action modulates motor system activation as well as behavioral predictions in the form of anticipatory eye-movements. Participants were presented with object-directed actions (e.g., making a cup of tea) consisting of three action steps which increased in their predictability. While the goal of the first step was ambiguous (e.g., when making tea, one can first grab the teabag or the cup), the goals of the following steps became predictable over the course of the action. Motor system activation was assessed by measuring attenuation of sensorimotor mu- and beta-oscillations. We found that mu- and beta-power were attenuated during observation, indicating general activation of the motor system. Importantly, predictive motor system activation, indexed by beta-band attenuation, increased for each action step, showing strongest activation prior to the final (i.e. most predictable) step. Sensorimotor activity was related to participants' predictive eye-movements which also showed a modulation by action step. Our results demonstrate that motor system activity and behavioral predictions become stronger for more predictable action steps. The functional roles of sensorimotor oscillations in predicting other's actions are discussed.

Understanding Behavioural Rigidity in Autism Spectrum Conditions: The Role of Intentional Control.

Although behavioural rigidity belongs to the core symptoms of autism spectrum conditions, little is known about its underlying cognitive mechanisms. The current study investigated the role of intentional control mechanisms in behavioural rigidity in autism. Autistic individuals and their matched controls were instructed to repeatedly choose between two simple cognitive tasks and to respond accordingly to the subsequently presented stimulus. Results showed that autistic participants chose to repeat tasks more often than their controls and when choosing to switch, they demonstrated larger performance costs. These findings illustrate that when required to make their own choices, autistic people demonstrate rigidity at different performance levels, suggesting that intentional control mechanisms might be important for a better understanding of behavioural rigidity in autism.

Binary sensitivity of theta activity for gain and loss when monitoring parametric prediction errors.

Several theories have been proposed to account for the medial frontal activity that is elicited during the evaluation of outcomes. Respectively, these theories claim that the medial frontal response reflects (i) the absolute deviation between the value of an outcome and its expected value (i.e. an absolute prediction error); (ii) the deviation between actual and expected outcomes, with a specific sensitivity to outcomes that are worse than expected (i.e. a negative prediction error); (iii) a binary evaluation in terms of good and bad outcomes. In the current electroencephalography study, participants were presented with cues that induced specific predictions for the values of trial outcomes (a gain or loss of points). The actual outcomes occasionally deviated from the predicted values, producing prediction errors with parametrically varying size. Analysis of the medial frontal theta activity in response to the outcomes demonstrated a specific sensitivity to the occurrence of a loss of points when a gain had been predicted. However, the absolute deviation with respect to the predicted value did not modulate the theta response. This finding is consistent with the idea that outcome monitoring activity measured over medial frontal cortex is sensitive to the binary distinction between good and bad outcomes.

Dissociable neural correlates of intention and action preparation in voluntary task switching.

This electroencephalographic (EEG) study investigated the impact of between-task competition on intentional control in voluntary task switching. Anticipatory preparation for an upcoming task switch is a hallmark of top-down intentional control. Meanwhile, asymmetries in performance and voluntary choice when switching between tasks differing in relative strength reveal the effects of between-task competition, reflected in a surprising bias against switching to an easier task. Here, we assessed the impact of this bias on EEG markers of intentional control during preparation for an upcoming task switch. The results revealed strong and varied effects of between-task competition on EEG markers of global task preparation-a frontal contingent negative variation (CNV), a posterior slow positive wave, and oscillatory activity in the alpha band (8-12 Hz) over posterior scalp sites. In contrast, we observed no between-task differences in motor-specific task preparation, as indexed by the lateralized readiness potential and by motor-related amplitude asymmetries in the mu (9-13 Hz) and beta (18-26 Hz) frequency bands. Collectively, these findings demonstrate that between-task competition directly influences the formation of top-down intentions, not only their expression in overt behavior. Specifically, this influence occurs at the level of global task intention rather than the preparation of specific actions.

Between-task competition for intentions and actions.

People can switch quickly and flexibly from one task to another, but suffer the effects of between-task competition when they do so: After switching, they tend to be distracted by irrelevant stimulus information and hampered by incorrect actions associated with recently performed tasks. This competition results in performance costs of switching, as well as a bias against switching when there is choice over which task to perform, particularly when switching from a difficult task to an easier one. Two experiments investigated the locus of these between-task competition effects in voluntary task switching. Participants switched between an easy location classification and a harder shape classification, making two responses on each trial: the first to register their task choice, the second to perform the chosen task on a subsequently presented stimulus. The results indicated that participants chose to perform the difficult shape task more often than the easier location task, evidence that between-task competition affects intentions that are expressed independently of task-specific actions. The bias was stronger in participants with faster choice speed, suggesting that these influences are relatively automatic. Moreover, even though participants had unlimited time to choose and prepare a task before stimulus presentation, their subsequent performance was nonetheless sensitive to persisting effects of between-task competition. Altogether these results indicate the pervasive influence of between-task competition, which affects both the expression of global task intentions and the production of task-specific actions.

Reduced accuracy and sensitivity in the perception of emotional facial expressions in individuals with high autism spectrum traits.

Autism spectrum disorder (ASD) is among other things characterized by specific impairments in emotion processing. It is not clear, however, to what extent the typical decline in affective functioning is related to the specific autistic traits. We employed The Autism Spectrum-Quotient (AQ) to quantify autistic traits in a group of 500 healthy individuals and investigate whether we could detect similar difficulties in the perception of emotional expressions in a broader autistic phenotype. The group with high AQ score was less accurate and needed higher emotional content to recognize emotions of anger, disgust, and sadness. Our findings demonstrate a selective impairment in identification of emotional facial expressions in healthy individuals that is primarily related to the extent of autistic traits.

A review of intentional and cognitive control in autism.

Different clinical studies have provided empirical evidence for impairments in cognitive control in individuals with autism spectrum disorders (ASD). The challenge arises, however, when trying to specify the neurocognitive mechanisms behind the reported observations of deviant patterns of goal-directed behavior in ASD. Studies trying to test specific assumptions by applying designs that are based on a more controlled experimental conditions often fail in providing strong evidence for an impairment in specific cognitive functions. In this review, we summarize and critically reflect on behavioral findings and their theoretical explanations regarding cognitive control processing in autism, also from a developmental perspective. The specific focus of this review is the recent evidence of deficits in intentional control - a specific subset of cognitive control processes that biases the choice of our behavioral goals - coming from different research fields. We relate this evidence to the cognitive rigidity observed in ASD and argue that individuals with ASD experience problems at the intentional level rather than at the level of implementation of intentions. Both these processes are related to cognitive control mechanisms but in different ways. Finally, we discuss new directions in studying cognitive control in ASD and how these relate to adaptive cognition.

Cognitive control of intentions for voluntary actions in individuals with a high level of autistic traits.

Impairments in cognitive control generating deviant adaptive cognition have been proposed to account for the strong preference for repetitive behavior in autism. We examined if this preference reflects intentional deficits rather than problems in task execution in the broader autism phenotype using the Autism-Spectrum Quotient (AQ). Participants chose between two tasks differing in their relative strength by indicating first their voluntary task choice and then responding to the subsequently presented stimulus. We observed a stronger repetition bias for the harder task in high AQ participants, with no other differences between the two groups. These findings indicate that the interference between competing tasks significantly contributes to repetitive behavior in autism by modulating the formation of task intentions when choosing tasks voluntarily.

Impaired task switching performance in children with dyslexia but not in children with autism.

Problems with cognitive control in both autism and dyslexia have already been reported in different studies. The present study specifically examined task-switching performance in children with autism and dyslexia. For this purpose, a multiple-trial paradigm was used with cues for colour- and shape-matching tasks presented before a run of trials. The cue could imply a task switch (when the cue changed the task) or a task repetition (when the cue did not change the task). Both reaction times and error rates were measured for switching, restarting, and general task performance. Participants were children with autism (24) and with dyslexia (25) and healthy controls (27) with normal IQ and ages from 12 to 18 years. The main finding was that while similar switching performance was observed between children with autism and the healthy controls, children with dyslexia showed a significant switch-specific delay relative to both healthy controls and children with autism. Furthermore, no deficit in restarting performance was observed for any of the two patient groups. Finally, additional evidence is provided for a more general deficit in information processing in dyslexia. Our data suggest that children with autism are able to switch between tasks in a similar way as do normally developing children as long as the tasks are unambiguously specified. Furthermore, the data imply switch-specific deficits in dyslexia additionally to the deficits in general information processing already reported in the literature. The implications of our data are further discussed in relation to the interpretation of the Wisconsin Card Sorting Test.

Generic cognitive adaptations to task interference in task switching.

The present study investigated how the activation of previous tasks interferes with the execution of future tasks as a result of temporal manipulations. Color and shape matching tasks were organized in runs of two trials each. The tasks were specified by a cue presented before a task run, cueing only the first trials of each run. Response times (RTs) and error rates were measured for task switching and task repetition conditions. Task interference was varied as a function of response-cue interval (RCI of 300 and 900ms), that is, the interval between the task runs. Keeping the response-stimulus interval within the task runs constant at 300ms allowed the disentangling of the direct effects of RCI manipulation on performance (first trials) from the general effects on performance (both trials in the run). The data showed similar performance improvement due to RCI increase on both trials in the task run. Furthermore, increasing RCI improved both switch and repetition performance to a similar extent. Together, our findings provide further evidence for accounts stressing generic effects of proactive task interference in task switching.

Understanding the flexibility of action-perception coupling.

The idea that observing an action triggers an automatic and obligatory activation of an imitative action in the motor system of the observer has recently been questioned by studies examining complementary actions. Instead of a tendency for imitation, cooperative settings may facilitate the execution of dissimilar actions, resulting in a relative disadvantage for imitative actions. The present study aimed at clarifying the contribution of associative learning and interference of task representations to the reversal of congruency effects. To distinguish between the two, an experiment was designed, in which we increased the effects of associative learning and minimized the effects of task interference. Participants completed a series of imitation and complementary action runs, in which they continuously imitated or complemented the actions of a virtual co-actor. Each run was alternated with a test run showing the same actions but including color-cues, and the participants were instructed to respond to color instead of the actor's posture. Reaction times to test runs showed no reversal of facilitation effects between the imitation and complementary action conditions. This result strongly argues that associative learning cannot adequately account for reversed facilitation effects. Our study provides additional support for action-perception models that allow flexible selection of action-perception coupling and challenges the existing models purely based on stimulus-response associations.

Dissociating restart cost and mixing cost in task switching.

Three experiments investigated the cognitive mechanisms underlying the restart cost and mixing cost in task switching. To this aim, the predictability of task order was varied (unpredictable in Experiment 1 and predictable in Experiments 2 and 3) across experiments, which employed a multiple-trial paradigm. Verbal cues for color and shape matching tasks were presented before a run of four trials. Focusing on task-repetition runs only, we measured restart cost as the difference in performance between trials 1 and 2 and mixing cost as the difference in performance on the non-cued trials under mixed-tasks conditions (Experiments 1 and 2) and single-task conditions (Experiment 3). The restart cost was observed under mixed-tasks conditions with both unpredictable and predictable task orders but not under the single-task condition. In contrast, the mixing cost was observed under the mixed-tasks condition with unpredictable task order only (Experiment 1). This finding implies that the optimal task execution on repetition trials depends on how predictable the identity of the approaching task is. Therefore, we suggest that mixing cost arises from limited preparation on repetition trials when task order is unpredictable, while restart cost arises from processes involved in cue-based task activation that is needed to resolve task interference. Together, these data suggest that restart cost and mixing cost are based on dissociable mechanisms.