Stephen Monsell | University of Exeter (original) (raw)
Papers by Stephen Monsell
Journal of Experimental Psychology: General, 1995
... Costs of a Predictable Switch Between Simple Cognitive Tasks Robert D. Rogers and Stephen Mon... more ... Costs of a Predictable Switch Between Simple Cognitive Tasks Robert D. Rogers and Stephen Monsell University of Cambridge ... Robert D. Rogers and Stephen Monsell, Department of Ex-perimental Psychology, University of Cambridge, Cambridge, England. ...
Journal of experimental psychology. General, 2015
Switching tasks costs time. Allowing time to prepare reduces the cost, but usually leaves an irre... more Switching tasks costs time. Allowing time to prepare reduces the cost, but usually leaves an irreducible "residual cost." Most accounts of this residual cost locate it within the response-selection stage of processing. To determine which processing stage is affected, we measured event-related potentials (ERPs) as participants performed a reading task or a perceptual judgment task, and examined the effect of a task switch on early markers of lexical processing. A task cue preceding a string of blue and red letters instructed the participant either to read the letter string (for a semantic classification in Experiment 1, and a lexical decision in Experiment 2) or to judge the symmetry of its color pattern. In Experiment 1, having to switch to the reading task delayed the evolution of the effect of word frequency on the reading task ERP by a substantial fraction of the effect on reaction time (RT). In Experiment 2, a task switch delayed the onset of the effect of lexical stat...
Brain : a journal of neurology, 2004
Executive functions such as task-set switching are thought to depend on the frontal cortex. Howev... more Executive functions such as task-set switching are thought to depend on the frontal cortex. However, more precision is required in identifying which components of such high-level processes relate to which, if any, subregions of the brain. In a recent study of 19 patients with focal right frontal (RF) lesions and 17 with left frontal (LF) lesions, we found that response inhibition, as measured by the stop-signal task, was specifically disrupted by damage to the right inferior frontal gyrus (IFG). The present study examined task-switching performance in this same group of patients and in matched controls on the grounds that inhibitory mechanisms may also be required to switch task-set. Both RF and LF patients showed significantly larger switch costs (the difference, in reaction time and errors, between changing tasks and repeating the same task) than controls, but apparently for different reasons. For RF patients, a part of the switch deficit could be accounted for by impaired inhibit...
Journal of Experimental Psychology: Human Perception and Performance, 2014
Among the potential, but neglected, sources of task-switch costs is the need to reallocate attent... more 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.
Memory & Cognition, 2003
Participants switched frequently between high/low and odd/even classification of a digit. The int... more Participants switched frequently between high/low and odd/even classification of a digit. The interval between a task cue and the next digit varied between blocks. In Experiment 1, the task switched predictably every two, four, or eight trials. In Experiment 2, switching predictably every four trials was compared with random switching. With predictable switching, the cost was limited to the first
Journal of Experimental Psychology-learning Memory and Cognition, 1992
Two experiments on oral reading of single words compared naming performance in pure blocks of non... more Two experiments on oral reading of single words compared naming performance in pure blocks of nonwords or exception words with performance in blocks of randomly mixed nonwords and exception words. Ss named exception words faster and made fewer regularization errors when they were not also prepared for nonwords. These data suggest Ss inhibit or ignore the computation of assembled phonology
Journal of Experimental Psychology: Learning, Memory, and Cognition, 2014
When stimuli afford multiple tasks, switching among them involves promoting one of several task-s... more When stimuli afford multiple tasks, switching among them involves promoting one of several task-sets in play into a most-active state. This process, often conceptualized as retrieving task parameters and stimulus-response (S-R) rules into procedural working memory, is a likely source of the reaction time (RT) cost of a task-switch, especially when no time is available for task preparation before the stimulus. We report 2 task-cuing experiments that asked whether the time consumed by task-set retrieval increases with the number of task-sets in play, while unconfounding the number of tasks with their frequency and recency of use. Participants were required to switch among 3 or 5 orthogonal classifications of perceptual attributes of an object (Experiment 1) or of phonological/semantic attributes of a word (Experiment 2), with a 100 or 1,300 ms cue-stimulus interval. For 2 tasks for which recency and frequency were matched in the 3- and 5-task conditions, there was no effect of number of tasks on the switch cost. For the other tasks, there was a greater switch cost in the 5-task condition with little time for preparation, attributable to effects of frequency/recency. Thus, retrieval time for active task-sets is not influenced by the number of alternatives per se (unlike several other kinds of memory retrieval) but is influenced by recency or frequency of use. (PsycINFO Database Record (c) 2015 APA, all rights reserved).
The Quarterly Journal of Experimental Psychology Section A, 1992
Psychonomic Bulletin & Review, 2002
Reaction time is typically longer on trials on which the task changes. This switch cost is reduce... more Reaction time is typically longer on trials on which the task changes. This switch cost is reduced by the opportunity to prepare for the change before the stimulus onset, but there remains a residual cost that resists reduction by further opportunity for preparation. De Jong (2000) proposed a model for evaluating the contribution to the residual cost of (1) failure to achieve endogenous task-set reconfiguration on a proportion of trials, and (2) limitations to the completeness of reconfiguration attainable by endogenous means. We report good fits of the model to the data from one previous and one new task-switching experiment, suggesting that the residual switch cost may indeed be attributable to a probabilistic failure to complete advance preparation. But strong incentives for preparation only marginally increased the estimated preparation probability, suggesting some intrinsic limitation to the ability to achieve endogenous preparation for a task switch on every trial.
Psychological Research, 2000
Switching between two tasks aorded by the same stimuli results in slower reactions and more error... more Switching between two tasks aorded by the same stimuli results in slower reactions and more errors on the ®rst stimulus after the task changes. This``switch cost'' is reduced, but not usually eliminated, by the opportunity to prepare for a task switch. While there is agreement that this preparation eect indexes a control process performed before the stimulus, the``residual'' cost has been attributed to several sources: to a control process essential for task-set recon®guration that can be carried out only after the stimulus onset, to probabilistic failure to engage in preparation prior to the stimulus, and to two kinds of priming from previous trials: positive priming of the now-irrelevant task set and inhibition of the now-relevant task-set. The main evidence for the carry-over of inhibition is the observation that it is easier to switch from the stronger to the weaker of a pair of tasks aorded by the stimulus than vice versa. We survey available data on interactions between task switching and three manipulations of relative task strength: pre-experimental experience, stimulus-response compatibility, and intra-experimental practice. We conclude that it is far from universally true that it is easier to switch to the weaker task. Either inhibition of the stronger task-set is a strategy used only in the special case of extreme inequality in strength, or its consequences for later performance may be masked by slower post-stimulus control operations for more complex tasks. Inhibitory priming may also be stimulus speci®c.
Memory & Cognition, 2003
Participants switched frequently between high/low and odd/even classification of a digit. The int... more Participants switched frequently between high/low and odd/even classification of a digit. The interval between a task cue and the next digit varied between blocks. In Experiment 1, the task switched predictably every two, four, or eight trials. In Experiment 2, switching predictably every four trials was compared with random switching. With predictable switching, the cost was limited to the first trial of a run. Random switching produced a more gradual approach to asymptotic performance. After one performance, control processes attenuate the resulting change in task-set bias if a further switch is likely, but this strategic modulation is soon overwhelmed by task-set priming through further performances. Preparation reduced switch costs but not interference from the irrelevant attribute: Control of interference appears to be reactive,not proactive. Switch costs did not increase with run length, suggesting that retrieval of the task set last associatedwith the stimulus did not contribute to switch costs.
Memory & Cognition, Jan 1, 2001
Journal of Experimental Psychology: Learning, Memory, and Cognition, 2014
Task-cuing experiments are usually intended to explore control of task set. But when small stimul... more Task-cuing experiments are usually intended to explore control of task set. But when small stimulus sets are used, they plausibly afford learning of the response associated with a combination of cue and stimulus, without reference to tasks. In 3 experiments we presented the typical trials of a task-cuing experiment: a cue (colored shape) followed, after a short or long interval, by a digit to which 1 of 2 responses was required. In a tasks condition, participants were (as usual) directed to interpret the cue as an instruction to perform either an odd/even or a high/low classification task. In a cue + stimulus → response (CSR) condition, to induce learning of mappings between cue-stimulus compound and response, participants were, in Experiment 1, given standard task instructions and additionally encouraged to learn the CSR mappings; in Experiment 2, informed of all the CSR mappings and asked to learn them, without standard task instructions; in Experiment 3, required to learn the mappings by trial and error. The effects of a task switch, response congruence, preparation, and transfer to a new set of stimuli differed substantially between the conditions in ways indicative of classification according to task rules in the tasks condition, and retrieval of responses specific to stimulus-cue combinations in the CSR conditions. Qualitative features of the latter could be captured by an associative learning network. Hence associatively based compound retrieval can serve as the basis for performance with a small stimulus set. But when organization by tasks is apparent, control via task set selection is the natural and efficient strategy.
Journal of Experimental Psychology: Learning, Memory, and Cognition, 1992
Two experiments on oral reading of single words compared naming performance in pure blocks of non... more Two experiments on oral reading of single words compared naming performance in pure blocks of nonwords or exception words with performance in blocks of randomly mixed nonwords and exception words. Ss named exception words faster and made fewer regularization errors ...
Journal of Experimental Psychology: Learning, Memory, and Cognition, 2013
Accounts of task-set control generally assume that the current task&a... more Accounts of task-set control generally assume that the current task's stimulus-response (S-R) rules must be elevated to a privileged state of activation. How are they represented in this state? In 3 task-cuing experiments, we tested the hypothesis that phonological working memory is used to represent S-R rules for task-set control by getting participants to switch between 2 sets of arbitrary S-R rules and manipulating the articulatory duration (Experiment 1) or phonological similarity (Experiments 2 and 3) of the names of the stimulus terms. The task cue specified which of 2 objects (Experiment 1) or consonants (Experiment 2) in a display to identify with a key press. In Experiment 3, participants switched between identifying an object/consonant and its color/visual texture. After practice, neither the duration nor the similarity of the stimulus terms had detectable effects on overall performance, task-switch cost, or its reduction with preparation. Only in the initial single-task training blocks was phonological similarity a significant handicap. Hence, beyond a very transient role, there is no evidence that (declarative) phonological working memory makes a functional contribution to representing S-R rules for task-set control, arguably because once learned, they are represented in nonlinguistic procedural working memory.
Journal of Experimental Psychology: Human Perception and Performance, 2003
It has been reported that it is harder to switch to a strong, well-practiced task from a weaker, ... more It has been reported that it is harder to switch to a strong, well-practiced task from a weaker, less-practiced task than vice versa. Three experiments replicated this surprising asymmetry and investigated how it is affected by a reduction in interference between tasks. Experiment 1 progressively delayed the onset of the stimulus attribute associated with the stronger task. Experiments 2 and 3 separated the response sets of the tasks. Both manipulations reduced, without eliminating, interference of the stronger with the weaker task but reversed the asymmetry of switch costs, resulting in a larger cost of switching to the weaker task. The results are interpreted in terms of a model of the interactions between control input, task strength, and task priming.
Journal of Experimental Psychology: Human Perception and Performance, 2003
Four experiments investigated the effect of recent selective practice on the cost of switching be... more Four experiments investigated the effect of recent selective practice on the cost of switching between 2 tasks afforded by letter-digit pairs: alphabet arithmetic and shape comparison. Experiments 1 and 2 found a greater cost associated with switching to the more recently practiced task: evidence that task-set inertia contributes to switching costs. Experiment 3 found this effect to be limited to trials on which a recently trained stimulus followed another such stimulus: a result problematic for all current theories of task-set priming. Experiment 4 showed that the effect of recent practice was eliminated by active preparation for a task switch: It appears that endogenous task-set preparation reduces the effects of task-set inertia. ((c) 2003 APA, all rights reserved)
Journal of Cognitive Neuroscience, 2003
Journal of Experimental …, 1989
Compared the effect of frequency on lexical decision time (LDT) with that on reaction time (RT) i... more Compared the effect of frequency on lexical decision time (LDT) with that on reaction time (RT) in four other tasks, for the same words and subjects. Exp. 1 yielded an effect on semantic categorization RT (person vs. thing) similar in size and form to the effect on LDT. Exp. 2 yielded a substantial effect for syntactic categorization (noun vs. adjective), although weaker than the effect on LDT. In Exp. 3, the effect on naming RT for stress-final disyllabic words was identical to that on LDT, whereas the effect for stress-initial words was weaker. Exp. 4 showed no effect of frequency on delayed naming RT. The data undermine recent arguments for a (mainly) postidentification task-specific locus of frequency effects but are compatible with the older assumption (also characteristic of new PDP learning models) that lexical identification is a major locus of frequency effects (perhaps together with retrieval of meaning or phonology). But effects at that locus may be masked or diluted by other processes.
Journal of Experimental Psychology: General, 1995
... Costs of a Predictable Switch Between Simple Cognitive Tasks Robert D. Rogers and Stephen Mon... more ... Costs of a Predictable Switch Between Simple Cognitive Tasks Robert D. Rogers and Stephen Monsell University of Cambridge ... Robert D. Rogers and Stephen Monsell, Department of Ex-perimental Psychology, University of Cambridge, Cambridge, England. ...
Journal of experimental psychology. General, 2015
Switching tasks costs time. Allowing time to prepare reduces the cost, but usually leaves an irre... more Switching tasks costs time. Allowing time to prepare reduces the cost, but usually leaves an irreducible "residual cost." Most accounts of this residual cost locate it within the response-selection stage of processing. To determine which processing stage is affected, we measured event-related potentials (ERPs) as participants performed a reading task or a perceptual judgment task, and examined the effect of a task switch on early markers of lexical processing. A task cue preceding a string of blue and red letters instructed the participant either to read the letter string (for a semantic classification in Experiment 1, and a lexical decision in Experiment 2) or to judge the symmetry of its color pattern. In Experiment 1, having to switch to the reading task delayed the evolution of the effect of word frequency on the reading task ERP by a substantial fraction of the effect on reaction time (RT). In Experiment 2, a task switch delayed the onset of the effect of lexical stat...
Brain : a journal of neurology, 2004
Executive functions such as task-set switching are thought to depend on the frontal cortex. Howev... more Executive functions such as task-set switching are thought to depend on the frontal cortex. However, more precision is required in identifying which components of such high-level processes relate to which, if any, subregions of the brain. In a recent study of 19 patients with focal right frontal (RF) lesions and 17 with left frontal (LF) lesions, we found that response inhibition, as measured by the stop-signal task, was specifically disrupted by damage to the right inferior frontal gyrus (IFG). The present study examined task-switching performance in this same group of patients and in matched controls on the grounds that inhibitory mechanisms may also be required to switch task-set. Both RF and LF patients showed significantly larger switch costs (the difference, in reaction time and errors, between changing tasks and repeating the same task) than controls, but apparently for different reasons. For RF patients, a part of the switch deficit could be accounted for by impaired inhibit...
Journal of Experimental Psychology: Human Perception and Performance, 2014
Among the potential, but neglected, sources of task-switch costs is the need to reallocate attent... more 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.
Memory & Cognition, 2003
Participants switched frequently between high/low and odd/even classification of a digit. The int... more Participants switched frequently between high/low and odd/even classification of a digit. The interval between a task cue and the next digit varied between blocks. In Experiment 1, the task switched predictably every two, four, or eight trials. In Experiment 2, switching predictably every four trials was compared with random switching. With predictable switching, the cost was limited to the first
Journal of Experimental Psychology-learning Memory and Cognition, 1992
Two experiments on oral reading of single words compared naming performance in pure blocks of non... more Two experiments on oral reading of single words compared naming performance in pure blocks of nonwords or exception words with performance in blocks of randomly mixed nonwords and exception words. Ss named exception words faster and made fewer regularization errors when they were not also prepared for nonwords. These data suggest Ss inhibit or ignore the computation of assembled phonology
Journal of Experimental Psychology: Learning, Memory, and Cognition, 2014
When stimuli afford multiple tasks, switching among them involves promoting one of several task-s... more When stimuli afford multiple tasks, switching among them involves promoting one of several task-sets in play into a most-active state. This process, often conceptualized as retrieving task parameters and stimulus-response (S-R) rules into procedural working memory, is a likely source of the reaction time (RT) cost of a task-switch, especially when no time is available for task preparation before the stimulus. We report 2 task-cuing experiments that asked whether the time consumed by task-set retrieval increases with the number of task-sets in play, while unconfounding the number of tasks with their frequency and recency of use. Participants were required to switch among 3 or 5 orthogonal classifications of perceptual attributes of an object (Experiment 1) or of phonological/semantic attributes of a word (Experiment 2), with a 100 or 1,300 ms cue-stimulus interval. For 2 tasks for which recency and frequency were matched in the 3- and 5-task conditions, there was no effect of number of tasks on the switch cost. For the other tasks, there was a greater switch cost in the 5-task condition with little time for preparation, attributable to effects of frequency/recency. Thus, retrieval time for active task-sets is not influenced by the number of alternatives per se (unlike several other kinds of memory retrieval) but is influenced by recency or frequency of use. (PsycINFO Database Record (c) 2015 APA, all rights reserved).
The Quarterly Journal of Experimental Psychology Section A, 1992
Psychonomic Bulletin & Review, 2002
Reaction time is typically longer on trials on which the task changes. This switch cost is reduce... more Reaction time is typically longer on trials on which the task changes. This switch cost is reduced by the opportunity to prepare for the change before the stimulus onset, but there remains a residual cost that resists reduction by further opportunity for preparation. De Jong (2000) proposed a model for evaluating the contribution to the residual cost of (1) failure to achieve endogenous task-set reconfiguration on a proportion of trials, and (2) limitations to the completeness of reconfiguration attainable by endogenous means. We report good fits of the model to the data from one previous and one new task-switching experiment, suggesting that the residual switch cost may indeed be attributable to a probabilistic failure to complete advance preparation. But strong incentives for preparation only marginally increased the estimated preparation probability, suggesting some intrinsic limitation to the ability to achieve endogenous preparation for a task switch on every trial.
Psychological Research, 2000
Switching between two tasks aorded by the same stimuli results in slower reactions and more error... more Switching between two tasks aorded by the same stimuli results in slower reactions and more errors on the ®rst stimulus after the task changes. This``switch cost'' is reduced, but not usually eliminated, by the opportunity to prepare for a task switch. While there is agreement that this preparation eect indexes a control process performed before the stimulus, the``residual'' cost has been attributed to several sources: to a control process essential for task-set recon®guration that can be carried out only after the stimulus onset, to probabilistic failure to engage in preparation prior to the stimulus, and to two kinds of priming from previous trials: positive priming of the now-irrelevant task set and inhibition of the now-relevant task-set. The main evidence for the carry-over of inhibition is the observation that it is easier to switch from the stronger to the weaker of a pair of tasks aorded by the stimulus than vice versa. We survey available data on interactions between task switching and three manipulations of relative task strength: pre-experimental experience, stimulus-response compatibility, and intra-experimental practice. We conclude that it is far from universally true that it is easier to switch to the weaker task. Either inhibition of the stronger task-set is a strategy used only in the special case of extreme inequality in strength, or its consequences for later performance may be masked by slower post-stimulus control operations for more complex tasks. Inhibitory priming may also be stimulus speci®c.
Memory & Cognition, 2003
Participants switched frequently between high/low and odd/even classification of a digit. The int... more Participants switched frequently between high/low and odd/even classification of a digit. The interval between a task cue and the next digit varied between blocks. In Experiment 1, the task switched predictably every two, four, or eight trials. In Experiment 2, switching predictably every four trials was compared with random switching. With predictable switching, the cost was limited to the first trial of a run. Random switching produced a more gradual approach to asymptotic performance. After one performance, control processes attenuate the resulting change in task-set bias if a further switch is likely, but this strategic modulation is soon overwhelmed by task-set priming through further performances. Preparation reduced switch costs but not interference from the irrelevant attribute: Control of interference appears to be reactive,not proactive. Switch costs did not increase with run length, suggesting that retrieval of the task set last associatedwith the stimulus did not contribute to switch costs.
Memory & Cognition, Jan 1, 2001
Journal of Experimental Psychology: Learning, Memory, and Cognition, 2014
Task-cuing experiments are usually intended to explore control of task set. But when small stimul... more Task-cuing experiments are usually intended to explore control of task set. But when small stimulus sets are used, they plausibly afford learning of the response associated with a combination of cue and stimulus, without reference to tasks. In 3 experiments we presented the typical trials of a task-cuing experiment: a cue (colored shape) followed, after a short or long interval, by a digit to which 1 of 2 responses was required. In a tasks condition, participants were (as usual) directed to interpret the cue as an instruction to perform either an odd/even or a high/low classification task. In a cue + stimulus → response (CSR) condition, to induce learning of mappings between cue-stimulus compound and response, participants were, in Experiment 1, given standard task instructions and additionally encouraged to learn the CSR mappings; in Experiment 2, informed of all the CSR mappings and asked to learn them, without standard task instructions; in Experiment 3, required to learn the mappings by trial and error. The effects of a task switch, response congruence, preparation, and transfer to a new set of stimuli differed substantially between the conditions in ways indicative of classification according to task rules in the tasks condition, and retrieval of responses specific to stimulus-cue combinations in the CSR conditions. Qualitative features of the latter could be captured by an associative learning network. Hence associatively based compound retrieval can serve as the basis for performance with a small stimulus set. But when organization by tasks is apparent, control via task set selection is the natural and efficient strategy.
Journal of Experimental Psychology: Learning, Memory, and Cognition, 1992
Two experiments on oral reading of single words compared naming performance in pure blocks of non... more Two experiments on oral reading of single words compared naming performance in pure blocks of nonwords or exception words with performance in blocks of randomly mixed nonwords and exception words. Ss named exception words faster and made fewer regularization errors ...
Journal of Experimental Psychology: Learning, Memory, and Cognition, 2013
Accounts of task-set control generally assume that the current task&a... more Accounts of task-set control generally assume that the current task's stimulus-response (S-R) rules must be elevated to a privileged state of activation. How are they represented in this state? In 3 task-cuing experiments, we tested the hypothesis that phonological working memory is used to represent S-R rules for task-set control by getting participants to switch between 2 sets of arbitrary S-R rules and manipulating the articulatory duration (Experiment 1) or phonological similarity (Experiments 2 and 3) of the names of the stimulus terms. The task cue specified which of 2 objects (Experiment 1) or consonants (Experiment 2) in a display to identify with a key press. In Experiment 3, participants switched between identifying an object/consonant and its color/visual texture. After practice, neither the duration nor the similarity of the stimulus terms had detectable effects on overall performance, task-switch cost, or its reduction with preparation. Only in the initial single-task training blocks was phonological similarity a significant handicap. Hence, beyond a very transient role, there is no evidence that (declarative) phonological working memory makes a functional contribution to representing S-R rules for task-set control, arguably because once learned, they are represented in nonlinguistic procedural working memory.
Journal of Experimental Psychology: Human Perception and Performance, 2003
It has been reported that it is harder to switch to a strong, well-practiced task from a weaker, ... more It has been reported that it is harder to switch to a strong, well-practiced task from a weaker, less-practiced task than vice versa. Three experiments replicated this surprising asymmetry and investigated how it is affected by a reduction in interference between tasks. Experiment 1 progressively delayed the onset of the stimulus attribute associated with the stronger task. Experiments 2 and 3 separated the response sets of the tasks. Both manipulations reduced, without eliminating, interference of the stronger with the weaker task but reversed the asymmetry of switch costs, resulting in a larger cost of switching to the weaker task. The results are interpreted in terms of a model of the interactions between control input, task strength, and task priming.
Journal of Experimental Psychology: Human Perception and Performance, 2003
Four experiments investigated the effect of recent selective practice on the cost of switching be... more Four experiments investigated the effect of recent selective practice on the cost of switching between 2 tasks afforded by letter-digit pairs: alphabet arithmetic and shape comparison. Experiments 1 and 2 found a greater cost associated with switching to the more recently practiced task: evidence that task-set inertia contributes to switching costs. Experiment 3 found this effect to be limited to trials on which a recently trained stimulus followed another such stimulus: a result problematic for all current theories of task-set priming. Experiment 4 showed that the effect of recent practice was eliminated by active preparation for a task switch: It appears that endogenous task-set preparation reduces the effects of task-set inertia. ((c) 2003 APA, all rights reserved)
Journal of Cognitive Neuroscience, 2003
Journal of Experimental …, 1989
Compared the effect of frequency on lexical decision time (LDT) with that on reaction time (RT) i... more Compared the effect of frequency on lexical decision time (LDT) with that on reaction time (RT) in four other tasks, for the same words and subjects. Exp. 1 yielded an effect on semantic categorization RT (person vs. thing) similar in size and form to the effect on LDT. Exp. 2 yielded a substantial effect for syntactic categorization (noun vs. adjective), although weaker than the effect on LDT. In Exp. 3, the effect on naming RT for stress-final disyllabic words was identical to that on LDT, whereas the effect for stress-initial words was weaker. Exp. 4 showed no effect of frequency on delayed naming RT. The data undermine recent arguments for a (mainly) postidentification task-specific locus of frequency effects but are compatible with the older assumption (also characteristic of new PDP learning models) that lexical identification is a major locus of frequency effects (perhaps together with retrieval of meaning or phonology). But effects at that locus may be masked or diluted by other processes.