EXPRESS: Temporal Aspects of Two Types of Backward Crosstalk in Dual-Tasks: An Analysis of Continuous Mouse-Tracking Data

Schonard C, Ulrich R, Janczyk M. EXPRESS: Temporal Aspects of Two Types of Backward Crosstalk in Dual-Tasks: An Analysis of Continuous Mouse-Tracking Data. Quarterly Journal of Experimental Psychology. 2022: 174702182211356.A common explanation for processing limitations in dual-tasking is the existence of a bottleneck during response selection, meaning that the selection of responses can only occur serially for different tasks. However, a large body of data shows that features of a (secondary) Task 2 can already influence the processing of a (primary) Task 1. Such effects are referred to as backward crosstalk effects (BCEs). In the present study, two types of such BCEs were investigated: the compatibility-based BCE, which depends on the dimensional (often spatial) overlap between task features, and a BCE based on a go/no-go task in Task 2 (no-go BCE). Joining a line of research that suggests different mechanisms for these two types of BCEs, we investigated them using a mouse tracking setup. Time continuous analyses revealed that the compatibility-based BCE triggered a spatial activation of the Task 2 response early during Task 1 processing, whereas the no-go BCE triggered an inhibitory effect in the case of a no-go Task 2, which spills over to Task 1 execution. This occurred, however, earlier in the time-course than expected. The results are discussed with regard to recent models of dual-task processing

Allocation of visuospatial attention indexes evidence accumulation for reach decisions

Schonard C, Heed T, Seegelke C. Allocation of visuospatial attention indexes evidence accumulation for reach decisions. bioRxiv. 2022.Visuospatial attention is a prerequisite for the performance of visually guided movements: Perceptual discrimination is regularly enhanced at target locations prior to movement initiation. It is known that this attentional prioritization evolves over the time of movement preparation; however, it is not clear whether this build-up simply reflects a time requirement of attention formation or whether, instead, attention build-up reflects the emergence of the movement decision. To address this question, we combined behavioral experiments, psychophysics, and computational decision-making models to characterize the time course of attention build-up during motor preparation. Participants (n = 46, 29 female) executed center-out reaches to one of two potential target locations and reported the identity of a visual discrimination target that occurred concurrently at one of various time-points during movement preparation and execution. Visual discrimination increased simultaneously at the two potential target locations but was modulated by the experiment-wide probability that a given location would become the final goal. Attention increased further for the location that was then designated as the final goal location, with a time course closely related to movement initiation. A sequential sampling model of decision-making predicted key temporal characteristics of attentional allocation. Together, these findings provide evidence that visuospatial attentional prioritization during motor preparation does not simply reflect that a spatial location has been selected as movement goal, but rather indexes the time-extended, cumulative decision that leads to selection, hence constituting a link between perceptual and motor aspects of sensorimotor decisions

The Backward Crosstalk Effect Does Not Depend on the Degree of a Preceding Response Conflict

Schonard C, Ulrich R, Janczyk M. The Backward Crosstalk Effect Does Not Depend on the Degree of a Preceding Response Conflict. Experimental Psychology. 2020;67(5):277-291.A common observation in dual tasking is a performance decrement in one or both tasks compared with single tasking. Besides, more specific interference occurs depending on certain characteristics of the two tasks. In particular, even Task 1 performance is often improved when responses in both tasks are compatible (e.g., both require left responses) compared to when they are incompatible: the compatibility-based backward crosstalk effect (BCE). Similar to what is observed for conflict tasks, the BCE is sequentially modulated: It is larger following compatible than following incompatible trials. Previous work has attributed this observation to adaptation effects triggered by response conflict arising during incompatible trials. In two experiments, we assessed sequential modulations following trials with different degrees of such a response conflict. In contrast to our expectations, a clear and sizeable sequential modulation was observed even under conditions where no BCE, and thus no empirical sign of an objective response conflict, was present in the previous trial. Therefore, our results show sequential modulations even without prior response conflict, which is not the (sole) trigger of sequential modulations accordingly. We discuss these results with regard to other potential triggers such as the subjective experience of conflict or difficulty, episodic retrieval, and repetitions of response combinations

Examination of a response-effect compatibility task with continuous mouse-movements: Free- vs. forced-choice tasks and sequential modulations.

Schonard C, Xiong A, Proctor R, Janczyk M. Examination of a response-effect compatibility task with continuous mouse-movements: Free- vs. forced-choice tasks and sequential modulations. American Journal of Psychology. 2021;134(4):415-439.According to ideomotor theory, we select actions by recalling and anticipating their sensory consequences, that is, their action effects. Compelling evidence for this theory comes from response- effect compatibility (REC) experiments, in which a response produces an effect with which it is either compatible or incompatible. For example, pressing a left/right response key is faster if it is predictably followed by an action effect on the same, compatible side compared with the other, incompatible side, even though the effect itself appears only after response time is measured. Recent studies investigated this effect with continuous responses (i.e., computer mouse movements) and reported an REC effect in a forced-choice but not in a free-choice task. From the key pressing literature, the opposite result pattern or no differences would have been expected. To clarify this issue, we report 3 experiments with mouse movement responses. Experiment 1 used a simpler scenario than in prior studies and found a similar result: The REC effect was evident in a forced-but not in a free-choice task. Also, sequential modulations of the REC effect were exploratorily analyzed and replicated with higher power in Experiment 2. However, Experiment 3 demonstrated that at least part of the REC effect with mouse movements can be attributed to stimulus-response compatibility (SRC), with a much smaller compatibility effect evident with a procedure for which SRC was reduced. We conclude that a sequentially modulated compatibility effect can be observed with mouse movements, but previous studies may have underestimated the contribution from SRC. The results are also discussed in terms of why the compatibility effect was observed in forced-but not free-choice tasks with mouse movement responses