Feature-Selective Attentional Modulations in Human Frontoparietal Cortex

Ester, Edward F.; Sutterer, David; Serences, John T.; Awh, Edward

doi:10.1523/jneurosci.3935-15.2016

Cited by 87 publications

(79 citation statements)

References 66 publications

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“…The recruitment of parieto-occipital regions is consistent with theories that link working memory to the maintenance of stimuli in sensory and higher cortical areas [9–12, 31, 32]. Indeed, the widespread decreases in alpha-band power observed during delay may reflect frontoparietal control and/or recruitment of the dorsal attention network [33, 34].…”

Section: Discussionsupporting

confidence: 83%

Bidirectional Frontoparietal Oscillatory Systems Support Working Memory

et al. 2017

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Summary The ability to represent and select information in working memory provides the neurobiological infrastructure for human cognition. For 80 years, dominant views of working memory have focused on the key role of prefrontal cortex (PFC) [1–8]. However, more recent work has implicated posterior cortical regions [9–12], suggesting that PFC engagement during working memory is dependent on the degree of executive demand. We provide evidence from neurological patients with discrete PFC damage that challenges the dominant models attributing working memory to PFC-dependent systems. We show that neural oscillations, which provide a mechanism for PFC to communicate with posterior cortical regions [13], independently subserve communications both to and from PFC – uncovering parallel oscillatory mechanisms for working memory. Fourteen PFC patients and 20 healthy, age-matched controls performed a working memory task where they encoded, maintained, and actively processed information about pairs of common shapes. In controls, the electroencephalogram (EEG) exhibited oscillatory activity in the low-theta range over PFC and directional connectivity from PFC to parieto-occipital regions commensurate with executive processing demands. Concurrent alpha-beta oscillations were observed over parieto-occipital regions, with directional connectivity from parieto-occipital regions to PFC, regardless of processing demands. Accuracy, PFC low-theta activity, and PFC ➔ parieto-occipital connectivity were attenuated in patients, revealing a PFC-independent, alpha-beta system. The PFC patients still demonstrated task proficiency, which indicates that the posterior alpha-beta system provides sufficient resources for working memory. Taken together, our findings reveal neurologically dissociable PFC and parieto-occipital systems, and suggest that parallel, bidirectional oscillatory systems form the basis of working memory.

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Section: Discussionsupporting

confidence: 83%

Bidirectional Frontoparietal Oscillatory Systems Support Working Memory

et al. 2017

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“…In the second analysis, we regressed trial-by-trial horizontal EOG recordings (in Quantifying Sources of Location Information Loss and Recovery. We evaluated potential sources of change in location-specific representations via curve-fitting analyses (e.g., Ester et al 2015;Ester et al 2016). We first computed a one-dimensional reconstructed representation of orientation for each participant by averaging location channel responses over time (separately for the first and second delay periods).…”

Section: Methodsmentioning

confidence: 99%

Retrospective cues mitigate information loss in human cortex during working memory storage

Ester

Nouri

Rodriguez

2018

Preprint

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Working memory (WM) enables the flexible representation of information over short intervals. It is well-established that WM performance can be enhanced by a retrospective cue presented during storage, yet the neural mechanisms responsible for this benefit are unclear. Here, we tested several explanations for retro-cue benefits by quantifying changes in spatial WM representations reconstructed from alpha-band (8-12 Hz) EEG activity recorded from human participants (both sexes) before and after presentation of a retrospective cue. This allowed us to track cue-related changes in WM representations with high temporal resolution (tens of milliseconds). Participants encoded the locations of two colored discs for subsequent report. During neutral trials an uninformative cue instructed participants to remember the locations of both discs across a blank delay, and we observed a monotonic decrease in the fidelity of reconstructed spatial WM representations with time. During valid trials a 100% reliable cue indicated the color of the disc participants would be probed to report. Critically, valid cues were presented immediately after termination of the encoding display (“valid early”, or VE trials) or midway through the delay period (“valid late” or VL trials). During VE trials the gradual loss of location-specific information observed during neutral trials was eliminated, while during VL trials it was partially reversed. Our findings suggest that retro-cues engage several different mechanisms that together serve to mitigate information loss during WM storage.Significance StatementWorking memory (WM) performance can be improved by a cue presented during storage. This effect, termed a retrospective cue benefit, has been used to explore the limitations of attentional prioritization in WM. However, the mechanisms responsible for retrospective cue benefits are unclear. Here we tested several explanations for retrospective cue benefits by examining how they influence WM representations reconstructed from human EEG activity. This approach allowed us to visualize, quantify, and track the effects of retrospective cues with high temporal resolution (on the order of tens of milliseconds). We show that under different circumstances retrospective cues can both eliminate and even partially reverse information loss during WM storage, suggesting that retrospective cue benefits have manifold origins.

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“…However, given that dorsal LPC is thought to be involved in visual attention (Corbetta and Shulman, 2002), it is possible that the bias towards memory representations in this region can be attributed to differences in attentional demands across our perception and memory tasks. Namely, if our memory task was more attentionally demanding than our perception task-which is plausible, but difficult to test-then feature representations in dorsal LPC may have been amplified by attention during memory retrieval (Silver, 2005;Sprague and Serences, 2013;Ester et al, 2016). In either case, the fact that dorsal LPC actively represents visual features of retrieved stimuli is an important finding.…”

Section: Transformation Of Representations From Otc To Lpcmentioning

confidence: 95%

Parietal representations of stimulus features are amplified during memory retrieval and flexibly aligned with top-down goals

Favila

Samide

Sweigart

et al. 2018

Preprint

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In studies of human episodic memory, the phenomenon of reactivation has traditionally been observed in regions of occipitotemporal cortex (OTC) involved in sensory experience. However, reactivation also occurs in lateral parietal cortex (LPC), and recent evidence indicates that reactivation of stimulus-specific information may be stronger in LPC than in OTC. These observations raise a number of questions about the nature of memory representations in LPC and their relation to representations in OTC. Here, we report two fMRI experiments that quantify stimulus feature information (color and object category) within LPC and OTC, separately during perception and memory retrieval, in male and female human subjects. Across both experiments, we show a clear dissociation between OTC and LPC: while feature information in OTC is relatively stronger during perception than memory, feature information in LPC is relatively stronger during memory than perception. Thus, while OTC and LPC represent common stimulus features, they preferentially represent this information during different stages. We show that this transformation of feature information across regions co-occurs with stimulus-level reinstatement within LPC and high-level OTC. In Experiment 2, we consider whether feature information in LPC during memory retrieval is flexibly and dynamically shaped by top-down goals. Indeed, we find that dorsal LPC preferentially represents retrieved feature information that addresses current goals. In contrast, ventral LPC represents retrieved features independent of current goals.Collectively, these findings provide insight into the nature and significance of mnemonic representations in LPC and constitute an important bridge between putative mnemonic and control functions of parietal cortex.Traditional models of episodic memory posit that sensory activity evoked during perception is reactivated during recollection (Kosslyn, 1980;Damasio, 1989). There is considerable evidence for such reactivation in visual regions of occipitotemporal cortex (OTC) (Wheeler et al., 2000;Polyn et al., 2005). However, recent human neuroimaging work indicates that stimulus information is also reactivated in lateral parietal cortex (LPC) (Kuhl and Chun, 2014;Chen et al., 2016;Lee and Kuhl, 2016;Xiao et al., 2017). While these findings accord with evidence for univariate increases in LPC BOLD activity during successful remembering (Wagner et al., 2005;Kuhl and Chun, 2014), they also raise important questions about whether and how representations of retrieved memories differ between LPC and OTC.Univariate fMRI studies have consistently found that, in contrast to sensory regions, ventral LPC exhibits low activation when perceptual events are experienced but high activation when these events are successfully retrieved (Daselaar, 2009;Kim et al., 2010). The idea that LPC is relatively more involved in memory retrieval than perception has also received support from recent pattern-based fMRI studies. Long, Lee, and Kuhl (2016) found that reactivation of previously l...

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Feature-Selective Attentional Modulations in Human Frontoparietal Cortex

Cited by 87 publications

References 66 publications

Bidirectional Frontoparietal Oscillatory Systems Support Working Memory

Bidirectional Frontoparietal Oscillatory Systems Support Working Memory

Retrospective cues mitigate information loss in human cortex during working memory storage

Parietal representations of stimulus features are amplified during memory retrieval and flexibly aligned with top-down goals

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