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Switching from automatic to controlled action by monkey medial frontal cortex,
- Nat Neurosci
, 2007
"... Human behavior is mostly composed of habitual actions that require little conscious control. Such actions may become invalid if the environment changes, at which point individuals need to switch behavior by overcoming habitual actions that are otherwise triggered automatically. It is unknown how th ..."
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Cited by 53 (3 self)
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Human behavior is mostly composed of habitual actions that require little conscious control. Such actions may become invalid if the environment changes, at which point individuals need to switch behavior by overcoming habitual actions that are otherwise triggered automatically. It is unknown how the brain controls this type of behavioral switching. Here we show that the presupplementary motor area (pre-SMA) in the medial frontal cortex has a function in switching from automatic to volitionally controlled action in rhesus macaque monkeys. We found that a group of pre-SMA neurons was selectively activated when subjects successfully switched to a controlled alternative action. Electrical stimulation in the pre-SMA replaced automatic incorrect responses with slower correct responses. A further test suggested that the pre-SMA enabled switching by first suppressing an automatic unwanted action and then boosting a controlled desired action. Our data suggest that the pre-SMA resolves response conflict so that the desired action can be selected. Most of our everyday actions are automatic, or have automatic components, for good reasons: they are fast, demand less effort and thus occur efficiently (for example, driving home from work through a familiar route or generating a prepotent response to accelerate upon seeing a green light). The action will continue automatically unless a new or surprising situation arises in the external environment. In such novel encounters (for example, with road work or a child on a crosswalk), the automatic action must be replaced with a deliberately controlled action (for example, making a detour through unfamiliar routes or stepping on the brake instead of automatically accelerating) 1,2 . This ability to switch actions under volitional control is the hallmark of executive functions. It allows individuals to flexibly adjust behavior to a changing environment in favor of new solutions at the cost of performance speed 3 . Although the distinction between automatic and controlled processing for human cognition has long been an important theme in the psychology literature 1,2,4,5 , neural substrates for the dual processing mechanism are largely unknown. This study probes a neural account for the control process whereby automatic responses are overcome and an alternative desired response is issued. It is known that the medial frontal cortex (MFC) is important in diverse aspects of higher motor control RESULTS Two rhesus monkeys (Macaca mulatta), T and S, were trained to perform a saccade-overriding task
Involvement of rostral prefrontal cortex in selection between stimulus-oriented and stimulusindependent thought
- Eur. J. Neurosci
, 2005
"... We used functional magnetic resonance imaging to investigate brain activity while healthy subjects performed three different tasks, each of which alternated between: (i) phases relying on stimulus-oriented thought (i.e. cognitive processes provoked by incoming sensory information); and (ii) phases r ..."
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Cited by 31 (15 self)
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We used functional magnetic resonance imaging to investigate brain activity while healthy subjects performed three different tasks, each of which alternated between: (i) phases relying on stimulus-oriented thought (i.e. cognitive processes provoked by incoming sensory information); and (ii) phases relying on stimulus-independent thought (i.e. cognitive processes that were not related to any information in the immediate sensory environment). Within each task, the two phases were matched as closely as possible. In all three tasks, lateral rostral prefrontal cortex was transiently activated by a switch between stimulus-oriented and stimulus-independent thought (regardless of the direction of the switch). Medial rostral prefrontal cortex consistently exhibited sustained activity for stimulus-oriented vs. stimulus-independent thought. These results suggest the involvement of rostral prefrontal cortex in selection between stimulus-oriented and stimulus-independent cognitive processes.
Common neural substrates for response selection across modalities and mapping paradigms
- J. Cogn. Neurosci
, 2003
"... & In many situations, people can only compute one stimulusto-response mapping at a time, suggesting that response selection constitutes a ‘‘central processing bottleneck’ ’ in human information processing. Using fMRI, we tested whether common or distinct brain regions were involved in response s ..."
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Cited by 29 (4 self)
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& In many situations, people can only compute one stimulusto-response mapping at a time, suggesting that response selection constitutes a ‘‘central processing bottleneck’ ’ in human information processing. Using fMRI, we tested whether common or distinct brain regions were involved in response selection across visual and auditory inputs, and across spatial and nonspatial mapping rules. We isolated brain regions involved in response selection by comparing two conditions that were identical in perceptual input and motor output, but differed in the complexity of the mapping rule. In the visual – manual task of Experiment 1, four vertical lines were positioned from left to right, and subjects pressed one of four keys to report which line was unique in length. In the auditory –manual task of Experiment 2, four tones were presented in succession, and subjects pressed one of four keys to report which tone was unique in duration. For both visual and auditory tasks, the mapping between target position and key position was either spatially compatible or incompatible. In the verbal task of Experiment 3, subjects used nonspatial mappings that were either compatible (‘‘same’ ’ if colors matched; ‘‘different’ ’ if they mismatched) or incompatible (the opposite). Extensive activation overlap was observed across all three experiments for incompatible versus compatible mapping in bilateral parietal and frontal regions. Our results indicate that common neural substrates are involved in response selection across input modalities and across spatial and nonspatial domains of stimulus-to-response mapping, consistent with behavioral evidence that response selection is a central process. &
Success and Failure Suppressing Reflexive Behavior
"... & The dynamic interplay between reflexive and controlled determinants of behavior is one of the most general organizing principles of brain function. A powerful analogue of this interplay is seen in the antisaccade task, which pits reflexive and willed saccadic mechanisms against one another. Ev ..."
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Cited by 23 (5 self)
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& The dynamic interplay between reflexive and controlled determinants of behavior is one of the most general organizing principles of brain function. A powerful analogue of this interplay is seen in the antisaccade task, which pits reflexive and willed saccadic mechanisms against one another. Eventrelated functional magnetic resonance imaging of the human brain showed greater prestimulus preparatory activity in the pre-supplementary motor area before voluntary antisaccades (saccades away from a target) compared with reflexive prosaccades (saccades to a target). Moreover, this preparatory activity was critically associated with reflex suppression; it predicted whether the reflex was later successfully inhibited in the trial. These data illustrate a mechanism for top-down control over reflexive behavior. &
Resolving dual-task interference: An fMRI study. Neuroimage 22: 748–754
, 2004
"... The human cognitive system is severely limited in the amount of information it can process simultaneously. When two tasks are presented within a short stimulus-onset-asynchrony (SOA), reaction time of each task, especially task 2, is dramatically delayed. Previous studies have shown that such delay ..."
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Cited by 19 (0 self)
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The human cognitive system is severely limited in the amount of information it can process simultaneously. When two tasks are presented within a short stimulus-onset-asynchrony (SOA), reaction time of each task, especially task 2, is dramatically delayed. Previous studies have shown that such delay is accompanied by increased activation in the right inferior frontal gyrus (GFi). In this study, we address the role of right GFi in resolving dual-task interference at two different stages: allocation of perceptual attention and response selection. We scan 12 subjects using functional MRI while they conduct two tasks—shape discrimination in task 1 and color discrimination in task 2—and vary the SOA between tasks as 100 or 1500 ms. The targets are located at the center or at the periphery. When both are at the center, they compete primarily for response selection. When both are at the periphery, they additionally compete for the allocation of perceptual attention. Results show that the right GFi and frontal operculum regions are significantly more active in the short SOA than the long SOA condition, but only when subjects attend to the periphery in both tasks. We conclude that the right lateral frontal regions are important for resolving dual-task interference at the perceptual attention stage.
Voluntary selection of task sets revealed by functional magnetic resonance imaging
- J. Cogn. Neurosci
, 2006
"... & In everyday life, we have to selectively adapt our behavior to different situations and tasks. In cognitive psychology, such adaptive behavior can be investigated with the task-switching paradigm. However, in contrast to everyday life, in experi-ments participants are unequivocally told which ..."
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Cited by 17 (2 self)
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& In everyday life, we have to selectively adapt our behavior to different situations and tasks. In cognitive psychology, such adaptive behavior can be investigated with the task-switching paradigm. However, in contrast to everyday life, in experi-ments participants are unequivocally told which task to perform. The present functional magnetic resonance imaging (fMRI) study was set out to investigate processes that are relevant when participants can decide by their own which task to perform. The number of tasks to choose from was varied between a forced condition (no choice) and two voluntary selection conditions (two or three choices). We expected to find prolonged reaction times as well as higher activa-tions within the midcingulate cortex for the choice condi-tions compared to the no-choice condition. The fMRI results revealed a significant activation difference for the choice con-ditions versus the no-choice condition. For the choice con-trast, activation was found in the rostral cingulate zone (RCZ) as well as the superior parietal lobule and the posterior part of the intraparietal sulcus. These activations revealed no selection-specific difference between three and two choices. Finally, a post hoc analysis showed that the activation in the RCZ is not associated with higher task-dependent re-sponse conflict when participants can select a task set. Taken together, these findings indicate that distinct brain areas are involved in the voluntary selection of abstract task set information. &
Common neural mechanisms for response selection and perceptual processing
"... Behavioral evidence supports a dissociation between response selection (stimulus-to-response mapping) and perceptual discrimination: the former may be subject to a central processing bottleneck, whereas the latter is not (Pashler, 1994). We previously (Jiang & Kanwisher, submitted) identified a ..."
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Cited by 14 (5 self)
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Behavioral evidence supports a dissociation between response selection (stimulus-to-response mapping) and perceptual discrimination: the former may be subject to a central processing bottleneck, whereas the latter is not (Pashler, 1994). We previously (Jiang & Kanwisher, submitted) identified a set of frontal and parietal regions involved in response selection as those that produce a stronger signal when subjects follow a difficult stimulus-to-response mapping rule than an easy mapping rule. Here we test whether any of these regions are selectively activated by response selection and not perceptual processing, as predicted by the central bottleneck view. In Experiment 1 subjects indicated which of four parallel lines was unique in length; Perceptual discrimination was indexed by a higher BOLD response when the discrimination was difficult versus easy. Stimuli and responses were closely matched across conditions. We found that all regions-of-interest (ROIs) engaged by response selection were also engaged by perceptual processing, arguing against the existence of mechanisms exclusively involved in response selection. In Experiments 2 and 3 we asked what processes might go on in these ROIs, such that they could be recruited by both response selection and perceptual processing. Our data argue against an account of this common activation in terms of spatial processing or general task difficulty. Thus, perceptual discrimination may recruit the same central processes that are engaged by response selection. Human cognitive abilities are astonishing: we remember events for decades, we acquire knowledge of the world and of ourselves, we recognize faces and objects in a glimpse, and we walk and talk and write and sing. Yet our cognitive limitations are also striking. We can only k...
Neurophysiological signature of effective anticipatory task-set control: a task-switching investigation
- Eur J Neurosci
, 2008
"... Changing between cognitive tasks requires a reorganization of cognitive processes. Behavioural evidence suggests this can occur in advance of the stimulus. However, the existence or detectability of an anticipatory task-set reconfiguration process remains controversial, in part because several neuro ..."
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Cited by 12 (0 self)
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Changing between cognitive tasks requires a reorganization of cognitive processes. Behavioural evidence suggests this can occur in advance of the stimulus. However, the existence or detectability of an anticipatory task-set reconfiguration process remains controversial, in part because several neuroimaging studies have not detected extra brain activity during preparation for a task switch relative to a task repeat. In contrast, electrophysiological studies have identified potential correlates of preparation for a task switch, but their interpretation is hindered by the scarcity of evidence on their relationship to performance. We aimed to: (i) identify the brain potential(s) reflecting effective preparation for a task-switch in a task-cuing paradigm that shows clear behavioural evidence for advance preparation, and (ii) characterize this activity by means of temporal segmentation and source analysis. Our results show that when advance preparation was effective (as indicated by fast responses), a protracted switch-related component, manifesting itself as widespread posterior positivity and concurrent right anterior negativity, preceded stimulus onset for 300 ms, with sources primarily in the left lateral frontal, right inferior frontal and temporal cortices. When advance preparation was ineffective (as implied by slow responses), or made impossible by a short cue–stimulus interval (CSI), a similar component, with lateral prefrontal generators, peaked 300 ms poststimulus. The protracted prestimulus component (which we show to be distinct from P3 or contingent negative variation, CNV) also correlated over subjects with a behavioural measure of preparation. Furthermore, its differential lateralization for word and picture cues was consistent with a role for verbal self-instruction in preparatory task-set reconfiguration.
Task switching versus cue switching: Using transition cuing to disentangle sequential effects in task-switching performance
- Journal of Experimental Psychology: Learning, Memory, and Cognition
, 2007
"... Recent methodological advances have allowed researchers to address confounds in the measurement of task-switch costs in task-switching performance by dissociating cue switching from task switching. For example, in the transition-cuing procedure, which involves presenting cues for task transitions ra ..."
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Cited by 10 (5 self)
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Recent methodological advances have allowed researchers to address confounds in the measurement of task-switch costs in task-switching performance by dissociating cue switching from task switching. For example, in the transition-cuing procedure, which involves presenting cues for task transitions rather than for tasks, cue transitions (cue switches and cue repetitions) and task transitions (task switches and task repetitions) can be examined in a complete factorial design. Transition cuing removes the confound between cue transitions and first-order task transitions, but it introduces a confound between cue transitions and longer task sequences. In the present study, transition cuing was studied with two cues per transition (REPEAT and AGAIN for task repetitions; SWITCH and CHANGE for task switches), enabling a partial deconfounding of cue transitions and task sequences. Two experiments revealed robust sequential effects, with higher order task transitions affecting performance when cue transitions were held constant and with cue transitions affecting performance when task sequences were held constant. Methodological and theoretical implications of these findings for research on task switching are discussed.
Multiple effects of prefrontal lesions on task-switching
"... This study examined the performance of 41 patients with focal prefrontal cortical lesions and 38 healthy controls on a task-switching procedure. Three different conditions were evaluated: single tasks without switches and two switching tasks with the currently relevant task signalled either 1500 ms ..."
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Cited by 8 (1 self)
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This study examined the performance of 41 patients with focal prefrontal cortical lesions and 38 healthy controls on a task-switching procedure. Three different conditions were evaluated: single tasks without switches and two switching tasks with the currently relevant task signalled either 1500 ms (Long Cue) or 200 ms (Short Cue) before the stimulus. Patients with Superior Medial lesions showed both a general slowing of reaction time (RT) and a significantly increased switch cost as measured by RT. No other prefrontal group showed this increased reaction time switch cost. Increased error rates in the switching conditions, on the other hand, were observed in patients with Inferior Medial lesions and, to a lesser extent, ones with Superior Medial lesions. Patients with left dorsolateral lesions (9/46v) showed slower learning of the task as indicated by a high error rate early on. Several different processes are involved in task-switching and these are selectively disrupted by lesions to specific areas of the frontal lobes.
