Transfer of strategic task components across unique tasks that share some common structures.

Flexible, adaptive behaviour depends on the application of prior learning to novel contexts (transfer). Transfer can take many forms, but the focus of the present study was on "task schemas"-learning strategies that guide the earliest stages of engaging in a novel task. The central aim was to examine the architecture of task schemas and determine whether strategic task components can expedite learning novel tasks that share some structural components with the training tasks. Groups of participants across two experiments were exposed to different training regimes centred around multiple unique tasks that shared some/all/none of the structural task components (the kinds of stimuli, classifications, and/or responses) but none of the surface features (the specific stimuli, classifications, and/or responses) with the test task (a dot-pattern classification task). Initial test performance was improved (to a degree) in all groups relative to a control group whose training did not include any of the structural components relevant to the test task. The strongest evidence of transfer was found in the motoric, perceptual + categorization, and full schema training groups. This observation indicates that training with some (or all) strategic task components expedited learning of a novel task that shared those components. That is, task schemas were found to be componential and were able to expedite learning a novel task where similar (learning) strategies could be applied to specific elements of the test task.

Serial or parallel proactive control of components of task-set? A task-switching investigation with concurrent EEG and eye-tracking.

Among the issues examined by studies of cognitive control in multitasking is whether processes underlying performance in the different tasks occur serially or in parallel. Here we ask a similar question about processes that pro-actively control task-set. In task-switching experiments, several indices of task-set preparation have been extensively documented, including anticipatory orientation of gaze to the task-relevant location (an unambiguous marker of reorientation of attention), and a positive polarity brain potential over the posterior cortex (whose functional significance is less well understood). We examine whether these markers of preparation occur in parallel or serially, and in what order. On each trial a cue required participants to make a semantic classification of one of three digits presented simultaneously, with the location of each digit consistently associated with one of three classification tasks (e.g., if the task was odd/even, the digit at the top of the display was relevant). The EEG positivity emerged following, and appeared time-locked to, the anticipatory fixation on the task-relevant location, which might suggest serial organisation. However, the fixation-locked positivity was not better defined than the cue-locked positivity; in fact, for the trials with the earliest fixations the positivity was better time-locked to the cue onset. This is more consistent with (re)orientation of spatial attention occurring in parallel with, but slightly before, the reconfiguration of other task-set components indexed by the EEG positivity.

A Small Platoon of Idiots Have Been Allowed to Flourish, but the Homunculus Has Not Been Erased from Memory.

Schmidt, Liefooghe and De Houwer's (2020) PEP model is able to explain many empirical effects commonly reported in task switching experiments without invoking an executive control homunculus. However, their claim that they have erased the homunculus from memory may be a little premature. Although they have gone a long way in dissolving, deconstructing and fractionating the executive, there remain several empirical effects that are difficult to explain under PEP, some of which they openly discuss. In the present commentary, I have described some findings from my own research on spatial attention in task switching using eye-tracking that I think PEP would also struggle to model, but which can easily be explained by active control processes. I conclude that PEP still has some way to go before the homunculus can be altogether erased from memory.

Learning in the absence of overt practice: a novel (previously unseen) stimulus can trigger retrieval of an unpracticed response.

Skilled performance is traditionally thought to develop via overt practice. Recent research has demonstrated that merely instructed stimulus-response (S-R) bindings can influence later performance and readily transfer across response modalities. In the present study, we extended this to include instructed category-response (C-R) associations. That is, we investigated whether merely instructed C-R bindings can trigger an unpracticed response (in a different modality) on perception of a novel (previously unseen) stimulus. In a learning-test design, participants had to classify stimuli by comparing them to perceptual category templates (Experiment 1) or semantic category descriptions (Experiment 2) presented prior to each block. During learning blocks, participants had to respond manually, respond vocally, or listen passively to the correct response being spoken. A manual response was always required at test. In test blocks, the categories could either be novel or repeated from the learning block, whereas half of the stimuli were always novel and half were always repeated from the learning block. Because stimulus and category repetitions were manipulated orthogonally, it was possible to directly compare the relative contribution of S-R and C-R associations to performance. In Experiment 1, test performance was enhanced by repeating the C-R bindings independently of the stimulus. In Experiment 2, there was also evidence of an S-R repetition benefit independent of the classification. Critically, instructed associations formed in one response modality were robust to changes in the required response, even when no overt response was required during training, indicating the need to update the traditional view of associative learning.

How Does the (Re)Presentation of Instructions Influence Their Implementation?

Instructions are so effective that they can sometimes affect performance beyond the instructed context. Such 'automatic' effects of instructions (AEI) have received much interest recently. It has been argued that AEI are restricted to relatively simple and specific S-R tasks or action plans. The present study put this idea further to the test. In a series of experiments based on the NEXT paradigm (Meiran, Pereg, Kessler, Cole, & Braver, 2015a) we investigated the specificity of AEI. In Experiment 1, we presented category-response instructions instead of S-R instructions. Nevertheless, we observed AEI for novel stimuli from the instructed category (Experiment 1a), and abstractness of the category did not modulate the size of the NEXT effect (Experiment 1b). However, Experiment 2 revealed specificity at the response level: AEI were much smaller in conditions where the instructed GO response is semantically related to, but procedurally different from the required NEXT response, compared to a condition where the NEXT and GO responses were the same. Combined, these findings indicate that AEI can occur when S(C)-R instructions are abstract at the stimulus level, arguing against previous proposals. However, AEI does seem to require specificity at the response level. We discuss implications for recent theories of instruction-based learning and AEI.

Transfer of learned category-response associations is modulated by instruction.

Although instructions often emphasize categories (e.g., odd number→left hand response) rather than specific stimuli (e.g., 3→left hand response), learning is often interpreted in terms of stimulus-response (S-R) bindings or, less frequently, stimulus-classification (S-C) bindings with little attention being paid to the importance of category-response (C-R) bindings. In a training-transfer paradigm designed to investigate the early stages of category learning, participants were required to classify stimuli according to the category templates presented prior to each block (Experiments 1-4). In some transfer blocks the stimuli, categories and/or responses could be novel or repeated from the preceding training phase. Learning was assessed by comparing the transfer-training performance difference across conditions. Participants were able to rapidly transfer C-R associations to novel stimuli but evidence of S-C transfer was much weaker and S-R transfer was largely limited to conditions where the stimulus was classified under the same category. Thus, even though there was some evidence that learned S-R and S-C associations contributed to performance, learned C-R associations seemed to play a much more important role. In a final experiment (Experiment 5) the stimuli themselves were presented prior to each block, and the instructions did not mention the category structure. In this experiment, the evidence for S-R learning outweighed the evidence for C-R learning, indicating the importance of instructions in learning. The implications for these findings to the learning, cognitive control, and automaticity literatures are discussed.

Self-paced preparation for a task switch eliminates attentional inertia but not the performance switch cost.

The performance overhead associated with changing tasks (the "switch cost") usually diminishes when the task is specified in advance but is rarely eliminated by preparation. A popular account of the "residual" (asymptotic) switch cost is that it reflects "task-set inertia": carry-over of task-set parameters from the preceding trial(s). New evidence for a component of "task-set inertia" comes from eye-tracking, where the location associated with the previously (but no longer) relevant task is fixated preferentially over other irrelevant locations, even when preparation intervals are generous. Might such limits in overcoming task-set inertia in general, and "attentional inertia" in particular, result from suboptimal scheduling of preparation when the time available is outside one's control? In the present study, the stimulus comprised 3 digits located at the points of an invisible triangle, preceded by a central verbal cue specifying which of 3 classification tasks to perform, each consistently applied to just 1 digit location. The digits were presented only when fixation moved away from the cue, thus giving the participant control over preparation time. In contrast to our previous research with experimenter-determined preparation intervals, we found no sign of attentional inertia for the long preparation intervals. Self-paced preparation reduced but did not eliminate the performance switch cost-leaving a clear residual component in both reaction time and error rates. That the scheduling of preparation accounts for some, but not all, components of the residual switch cost, challenges existing accounts of the switch cost, even those which distinguish between preparatory and poststimulus reconfiguration processes. (PsycINFO Database Record

The coupling between spatial attention and other components of task-set: A task-switching investigation.

Is spatial attention reconfigured independently of, or in tandem with, other task-set components when the task changes? We tracked the eyes of participants cued to perform one of three digit-classification tasks, each consistently associated with a distinct location. Previously we observed, on task switch trials, a substantial delay in orientation to the task-relevant location and tendency to fixate the location of the previously relevant task-"attentional inertia". In the present experiments the cues specified (and instructions emphasized) the relevant location rather than the current task. In Experiment 1, with explicit spatial cues (arrows or spatial adverbs), the previously documented attentional handicaps all but disappeared, whilst the performance "switch cost" increased. Hence, attention can become decoupled from other aspects of task-set, but at a cost to the efficacy of task-set preparation. Experiment 2 used arbitrary single-letter cues with instructions and a training regime that encouraged participants to interpret the cue as indicating the relevant location rather than task. As in our previous experiments, and unlike in Experiment 1, we now observed clear switch-induced attentional delay and inertia, suggesting that the natural tendency is for spatial attention and task-set to be coupled and that only quasi-exogenous location cues decouple their reconfiguration.

Attentional inertia and delayed orienting of spatial attention in task-switching.

Among the potential, but neglected, sources of task-switch costs is the need to reallocate attention to different attributes or objects. Even theorists who recognize the importance of attentional resetting in task-switching sometimes think it too efficient to result in significant behavioral costs. We examined the dynamics of spatial attention in a task-cuing paradigm using eye-tracking. Digits appeared simultaneously at 3 locations. A cue preceded this display by a variable interval, instructing the performance of 1 of 3 classification tasks (odd-even, low-high, inner-outer) each consistently associated with a location, so that task preparation could be tracked via fixation of the task-relevant location. Task-switching led to a delay in selecting the relevant location and a tendency to misallocate attention; the previously relevant location attracted attention much more than the other irrelevant location on switch trials, indicating "inertia" in attentional parameters rather than mere distractibility. These effects predicted reaction time switch costs within and over participants. The switch-induced delay was not confined to trials with slow/late orienting, but characteristic of most switch trials. The attentional pull of the previously relevant location was substantially reduced, but not eliminated, by extending the preparation interval to more than 1 sec, suggesting that attentional inertia contributes to the "residual" switch cost. A control condition, using identical displays but only 1 task, showed that these effects could not be attributed to the (small and transient) delays or inertia observed when the required orientation changed between trials in the absence of a task change.

More attention to attention? An eye-tracking investigation of selection of perceptual attributes during a task switch.

Switching tasks prolongs response times, an effect reduced but not eliminated by active preparation. To explore the role of attentional selection of the relevant stimulus attribute in these task-switch costs, we measured eye fixations in participants cued to identify either a face or a letter displayed on its forehead. With only 200 ms between cue and stimulus onsets, the eyes fixated the currently relevant region of the stimulus less and the irrelevant region more on switch than on repeat trials, at stimulus onset and for 500 ms thereafter, in a pattern suggestive of delayed orientation of attention to the relevant region on switch trials. With 800 ms to prepare, both switch costs and inappropriate fixations were reduced, but on switch trials participants still tended (relative to repeat trials) to fixate the now-irrelevant region more at stimulus onset and to maintain fixation on, or refixate, the irrelevant region more during the next 500 ms. The size of this attentional persistence was associated with differences in performance costs between and within participants. We suggest that reorientation of attention is an important, albeit somewhat neglected and controversial, component of advance task-set reconfiguration and that the task-set inertia (or reactivation) to which many attribute the residual task-switch cost seen after preparation includes inertia in (or reactivation of) attentional parameters.