Language-switch costs from comprehension to production might just be task-switch costs

Spanish–English bilinguals switched between naming pictures in one language and either reading-aloud or semantically classifying written words in both languages. When switching between reading-aloud and picture-naming, bilinguals exhibited no language switch costs in picture-naming even though they produced overt language switches in speech. However, when switching between semantic classification and picture-naming, bilinguals, especially unbalanced bilinguals, exhibited switch costs in the dominant language and switch facilitation in the nondominant language even though they never switched languages overtly. These results reveal language switching across comprehension and production can be cost-free when the intention remains the same. Assuming switch costs at least partially reflect inhibition of the nontarget language, this implies such language control mechanisms are recruited only under demanding task conditions, especially for unbalanced bilinguals. These results provide striking demonstration of adaptive control mechanisms and call into question previous claims that language switch costs necessarily transfer from comprehension to production.

Predictable Switching Between Recognition Memory and Magnitude Judgement Tasks: Effects and Implications

<p>Task switching and interruption effects—slower and (often) less accurate responses when a task changes compared to that when a task remains the same—have been investigated from both theoretical and applied vantage points (e.g., Altmann & Trafton, 2007; Jersild, 1927; Rogers & Monsell, 1995). The task switching research has typically used simple tasks with high stimulus-response (S-R) overlap, but there is a need to use different methods and tasks to test the boundaries of task switching effects and the theories used to explain them (Logan, 2003). This thesis examined the costs of switching between a recognition memory task, which is a more complex task than those typically used, and a magnitude judgement task (for the number of dots in a spatial array), which is the type of simple task that has been used (e.g., Altmann, 2002; Monsell, Sumner & Waters, 2003). Across seven experiments, participants switched between the recognition and magnitude tasks in predictable 1, 2, or 4-trial runs. The first two experiments examined task switching effects on recognition memory performance, with Experiment 2 investigating whether specific recognition processes (i.e., recollection and/or familiarity) were affected by switching tasks. Experiment 3 investigated the recovery from a task switch for both tasks and included a visual, task switch "reminder" cue in an attempt to improve switching performance. Finally, Experiments 4A, 4B, 5A, and 5B examined evidence for two well-known task switching phenomena, the practice effect and the preparation effect. The results led to four critical conclusions: (1) switching between two tasks with minimal S-R overlap produced significant RT and accuracy switch effects; (2) the cost to recognition memory accuracy did not reflect an impairment to controlled recollection processes; (3) the magnitude and persistence of task switching effects changed as a function of practice within an experiment; and (4) there was little evidence that participants began to switch tasks in advance of stimulus presentation. The results reported in this thesis provide a clear example of task switching driven by the type of stimulus (word or dots), where a change in stimulus type (i.e., from word to dots array or vice versa) initiated the time consuming process of retrieving/activating the appropriate task set. Future research will need to clarify whether the stimulus-driven nature of switching between the recognition and magnitude tasks remains when using different task switching paradigms and when S-R overlap is reintroduced.</p>

Predictable Switching Between Recognition Memory and Magnitude Judgement Tasks: Effects and Implications

<p>Task switching and interruption effects—slower and (often) less accurate responses when a task changes compared to that when a task remains the same—have been investigated from both theoretical and applied vantage points (e.g., Altmann & Trafton, 2007; Jersild, 1927; Rogers & Monsell, 1995). The task switching research has typically used simple tasks with high stimulus-response (S-R) overlap, but there is a need to use different methods and tasks to test the boundaries of task switching effects and the theories used to explain them (Logan, 2003). This thesis examined the costs of switching between a recognition memory task, which is a more complex task than those typically used, and a magnitude judgement task (for the number of dots in a spatial array), which is the type of simple task that has been used (e.g., Altmann, 2002; Monsell, Sumner & Waters, 2003). Across seven experiments, participants switched between the recognition and magnitude tasks in predictable 1, 2, or 4-trial runs. The first two experiments examined task switching effects on recognition memory performance, with Experiment 2 investigating whether specific recognition processes (i.e., recollection and/or familiarity) were affected by switching tasks. Experiment 3 investigated the recovery from a task switch for both tasks and included a visual, task switch "reminder" cue in an attempt to improve switching performance. Finally, Experiments 4A, 4B, 5A, and 5B examined evidence for two well-known task switching phenomena, the practice effect and the preparation effect. The results led to four critical conclusions: (1) switching between two tasks with minimal S-R overlap produced significant RT and accuracy switch effects; (2) the cost to recognition memory accuracy did not reflect an impairment to controlled recollection processes; (3) the magnitude and persistence of task switching effects changed as a function of practice within an experiment; and (4) there was little evidence that participants began to switch tasks in advance of stimulus presentation. The results reported in this thesis provide a clear example of task switching driven by the type of stimulus (word or dots), where a change in stimulus type (i.e., from word to dots array or vice versa) initiated the time consuming process of retrieving/activating the appropriate task set. Future research will need to clarify whether the stimulus-driven nature of switching between the recognition and magnitude tasks remains when using different task switching paradigms and when S-R overlap is reintroduced.</p>

Towards a taxonomy of inhibition-related processes: A dual-task approach

The ability to inhibit responses is key to controlled behavior and is commonly investigated with the stop-signal paradigm. The authors investigated how response inhibition is situated within a taxonomy of control processes by combining multiple forms of control within novel dual tasks. Response inhibition, as measured by stop-signal reaction time (SSRT), was impaired when combined with shape matching, but not the flanker task, and when combined with cued task switching, but not predictable task switching, suggesting that response inhibition may be weakly or variably impaired when combined with selective attention and set switching demands, respectively. Response inhibition was consistently impaired when combined with the N-back or directed forgetting tasks, putative measures of working memory. Impairments of response inhibition by other control demands appeared to be driven by task context rather than evoked control demands, as SSRT slowing was similar for trials where control demands were either present (e.g., task switch) or absent (e.g., task stay). These results were initially identified in a discovery sample and subsequently validated in a pre-registered analysis of a held-out sample of subjects (N = 33 and 33, respectively). Taken together, these results show that response inhibition processes are often impaired in the context of other control demands, even on trials where direct engagement of those other control processes is not required. This suggests a taxonomy of control in which response inhibition overlaps with related control processes, especially working memory.

Distinct but correlated latent factors support the regulation of learned conflict-control and task-switching

Cognitive control is guided by learning, as people adjust control to meet changing task demands. The two best-studied instances of “control-learning” are the enhancement of attentional task focus in response to increased frequencies of incongruent distracter stimuli, reflected in the list-wide proportion congruent (LWPC) effect, and the enhancement of switch-readiness in response to increased frequencies of task switches, reflected in the list-wide proportion switch (LWPS) effect. However, the cognitive architecture underpinning these adaptations in cognitive stability and flexibility – specifically, whether there is a single, domain-general, or multiple, domain-specific learners – is currently not known. To reveal the latent structure of control-learning, we had a large sample of participants (N = 950) perform LWPC and LWPS paradigms, and afterwards assessed their explicit awareness of the task manipulations, as well as general cognitive ability and motivation. Confirmatory factor analysis was used to evaluate several preregistered models representing different plausible hypotheses concerning the latent structure of control-learning. Task performance replicated standard LWPC and LWPS effects. Crucially, the model that best fit the data had correlated domain- and context-specific latent factors. In other words, people’s ability to adapt their on-task focus and between-task switch-readiness to changing levels of demand was mediated by distinct (though correlated) underlying factors. Model fit remained good when accounting for variance in individual cognitive ability and self-reported motivation, as well as self-reported explicit awareness of manipulations and the order in which different levels of demand were experienced. Implications of these results for the cognitive architecture of dynamic cognitive control are discussed.

Learning the marginal value of mental effort over time

In keeping with the view that individuals invest cognitive effort in accordance with its relative costs and benefits, reward incentives typically improve performance in tasks that require cognitive effort. At the same time, increasing effort investment may confer larger or smaller performance benefits—i.e., the marginal value of effort—depending on the situation, or context. On this view, we hypothesize that the magnitude of reward-induced effort modulations should depend critically on the marginal value of effort for the given context, and furthermore, the marginal value of effort of a context should be learned over time as a function of direct experience in the context. Using two well-characterized cognitive control tasks and simple computational models, we demonstrate that individuals appear to learn the marginal value of effort for different contexts. In a task-switching paradigm (Experiment 1), we found that participants initially exhibited reward-induced switch cost reductions across contexts—here, task switch rates—but over time learned to only increase effort in contexts with a comparatively larger marginal utility of effort. Likewise, in a Flanker task (Experiment 2), we observed a similar learning effect across contexts defined by the proportion of incongruent trials. Together, these results enrich theories of cost-benefit effort decision-making by highlighting the importance of the (learned) marginal utility of cognitive effort.

Developmental Differences in the Availability of Cognitive Resources Supporting Rhyming and Dual Tasking

Purpose We investigated developmental differences in a dual task involving rhyming and tone judgment/decisions and the effects of varying cognitive demands on task performance. Method Participants were 7- to 11-year-olds, 12- to 15-year-olds, and adults between 18 and 40 years ( n = 19 per group). The rhyming task consisted of three stimuli categories (nonrhyme, rhyme, and replica), and the tone task stimuli were presented at short (100 ms) versus long (900 ms) stimulus onset asynchrony (SOA) from the onset of the rhyme task to vary cognitive demands. Response time (RT) and error data were analyzed using linear and binomial mixed-methods analysis, respectively. Results and Conclusions Adults did not show an SOA-based effect in rhyming RT, while the 12- to 15-year-olds showed the most effect (RT, long > short SOA). Response to the replica category was significantly faster than for the other categories in all age groups. A reverse SOA effect was evident in the tone task (RT, short > long SOA) in all age groups. The 7- to 11-year-olds showed twice the task switch cost effect in the tone task RT. Age grouping and phoneme awareness were significant predictors of performance in both tasks, and additionally, SOA was a significant predictor of performance in the secondary task. The findings have implications for (a) understanding maturational differences in rhyming and executive control for dual tasking and the cognitive mechanisms supporting such effects and (b) identifying variables contributing to the developmental differences.