Time Course of Executive Processes: Data from the Event‐Related Optical Signal

Gratton, Gabriele; Low, Kathy A.; Fabiani, Monica

doi:10.1093/acprof:oso/9780195314274.003.0012

Cited by 10 publications

(18 citation statements)

References 77 publications

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“…The localization of this response corresponds closely to that observed in previous fMRI studies of task switching (Braver et al, 2003; DiGirolamo et al, 2001; Dove et al, 2000). The location of this optical activity and its peak latency also correspond closely to those we observed in a variety of other preparatory conditions (see Agran et al, submitted; Gratton et al, 2008). All these studies indicate that this left MFG activity is, in fact, one in a series of activities within the FPN during task preparation and attention control.…”

Section: Resultssupporting

confidence: 86%

“…These data indicate that a set of brain areas, sometimes labeled the ‘‘fronto-parietal network’’ (FPN; Gilbert & Shallice, 2002; Mesulam, 1990; Posner & Petersen, 1990), may be involved in task switching and executive function in general. As these areas appear to be activated across a variety of tasks and conditions, we will label them ‘‘domain- or task-general’’ areas (e.g., Gratton, Low, & Fabiani, 2008; Gray, Chabris, & Braver, 2003; see also Köhler, Moscovitch, Winocur, Houle, & McIntosh, 1998 for a similar concept in the context of episodic memory).…”

Section: Introductionmentioning

confidence: 99%

“…Another possibility is that task switching can be accomplished via interactions among task-specific regions, even in the absence of direct top–down influence from task-general structures (see Agran et al, submitted; Gratton et al, 2008). For instance, the occurrence of a particular cue indicating the need for task switching may activate a task-specific region directly which, in turn, may inhibit other task-specific regions and bias the system toward using a particular dimension to process information.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Does White Matter Matter? Spatio-temporal Dynamics of Task Switching in Aging

Gratton¹,

Wee²,

Rykhlevskaia³

et al. 2009

Journal of Cognitive Neuroscience

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Older adults often encounter difficulties in switching between tasks, perhaps because of agerelated decreases in executive function. Executive function may largely depend on connections between brain areas-connections that may become structurally and functionally weaker in aging.Here we investigated functional and structural age-related changes in switching between a spatial and a verbal task. These tasks were chosen because they are expected to differentially use the two hemispheres. Brain measures included anatomical information about anterior corpus callosum size (CC; the major commissure linking the left and right hemisphere), and the event-related optical signal (EROS). Behavioral results indicated that older adults had greater task-switching difficulties, which, however, were largely restricted to switching to the spatial task and to individuals with smaller anterior CCs. The EROS data showed both general switching-related activity in the left middle frontal gyrus (with approximately 300-msec latency) and task-specific activity in the inferior frontal gyrus, lateralized to the left for the switch-to-verbal condition and to the right for the switch-to-spatial condition. This lateralization was most evident in younger adults. In older adults, activity in the switch-to-spatial condition was lateralized to the right hemisphere in individuals with large CC, and to the left in individuals with small CC. These data suggest that (a) task switching may involve both task-general and task-specific processes; and (b) white matter changes may underlie some of the age-related problems in switching. These effects are discussed in terms of the hypothesis that aging involves some degree of cortical disconnection, both functional and anatomical.

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Section: Resultssupporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Does White Matter Matter? Spatio-temporal Dynamics of Task Switching in Aging

Gratton¹,

Wee²,

Rykhlevskaia³

et al. 2009

Journal of Cognitive Neuroscience

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“…The parietal switch effect in the current study, however, did not predict subsequent modality-specific switching effects, suggesting that it was related to a general alerting of attention and may simply relay a signal that a change is needed in the pFC. Indeed, previous studies suggest that prefrontal regions are more involved in memory representations, whereas parietal regions are more important in representing stimulus-response associations (Gratton, Low, & Fabiani, 2008;Corbetta & Shulman, 2002). Previous work also finds that propagation of activity typically proceeds in an anterior to posterior direction, the opposite of what we found.…”

Section: Discussioncontrasting

confidence: 84%

“…Left frontal activity is commonly observed in paradigms that require resolution of interference during response selection or execution (Nelson, Reuter-Lorenz, Persson, Sylvester, & Jonides, 2009;Gratton et al, 2008). As revealed by the small switch costs from switching response modality, there may have been little or even no competition between representations.…”

Section: Discussionmentioning

confidence: 99%

Frontoparietal Traffic Signals: A Fast Optical Imaging Study of Preparatory Dynamics in Response Mode Switching

Baniqued

Low

Fabiani³

et al. 2013

Journal of Cognitive Neuroscience

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Coordination between networks of brain regions is important for optimal cognitive performance, especially in attention demanding tasks. With the event-related optical signal (a measure of changes in optical scattering because of neuronal activity) we can characterize rapidly evolving network processes by examining the millisecond-scale temporal correlation of activity in distinct regions during the preparatory period of a response mode switching task. Participants received a precue indicating whether to respond vocally or manually. They then saw or heard the letter "L" or "R," indicating a "left" or "right" response to be implemented with the appropriate response modality. We employed lagged cross-correlations to characterize the dynamic connectivity of preparatory processes. Our results confirmed coupling of frontal and parietal cortices and the trial-dependent relationship of the right frontal cortex with response preparation areas. The frontal-to-modality-specific cortex cross-correlations revealed a pattern in which first irrelevant regions were deactivated, and then relevant regions were activated. These results provide a window into the subsecond scale network interactions that flexibly tune to task demands.

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Dynamics of alpha suppression index both modality specific and general attention processes

Clements

Gyurkovics

Low

et al. 2022

Preprint

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EEG alpha power varies under many circumstances requiring visual attention. However, mounting evidence indicates that alpha may not only serve visual processing, but also the processing of stimuli presented in other sensory modalities, including hearing. We previously showed that alpha dynamics during an auditory task vary as a function of competition from the visual modality (Clements et al., 2022) suggesting that alpha may be engaged in multimodal processing. Here we assessed the impact of allocating attention to the visual or auditory modality on alpha dynamics, during the preparatory period of a bimodal-cued conflict task. In this task, precues indicated the modality (vision, hearing) relevant to a subsequent reaction stimulus. This task afforded us the opportunity to assess alpha during modality-specific preparation and while switching between modalities. Alpha suppression following the precue occurred in all conditions indicating that it may reflect general preparatory mechanisms. However, we observed a switch effect when preparing to attend to the auditory modality, in which greater alpha suppression was elicited when switching to the auditory modality compared to repeating. No switch effect was evident when preparing to attend to visual information (although robust suppression did occur in both conditions). In addition, waning alpha suppression preceded error trials, irrespective of sensory modality. These findings indicate that alpha can be used to monitor the level of preparatory attention to process both visual and auditory information. These results support the emerging view that alpha band activity may index a general attention control mechanism used across modalities, at least vision and hearing.

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Time Course of Executive Processes: Data from the Event‐Related Optical Signal

Cited by 10 publications

References 77 publications

Does White Matter Matter? Spatio-temporal Dynamics of Task Switching in Aging

Does White Matter Matter? Spatio-temporal Dynamics of Task Switching in Aging

Frontoparietal Traffic Signals: A Fast Optical Imaging Study of Preparatory Dynamics in Response Mode Switching

Dynamics of alpha suppression index both modality specific and general attention processes

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