Mapping the Dark Side: Visual Selectivity of Default Network Deactivations

Knapen, Tomas; Es, Daan Van; Barendregt, Martijn

doi:10.1101/292524

Cited by 3 publications

(2 citation statements)

References 27 publications

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“…The visual hierarchy also has multiple representations of the retina, laid out in topological maps that are commonly called retinotopic maps (Felleman and Van Essen, 1991; Sereno et al., 1995). While it was once thought that retinotopy was a property of lower level visual areas, it is now known that areas such as MT+ and MST also contain retinotopic maps (known as TO1 and TO2 respectively; (Amano et al., 2009), as do the frontal eye fields (Kastner et al., 2007) and even the default mode network (Knapen et al., 2018). Indeed, despite the large receptive field sizes within primate MT/V5, it is possible to track object position at the population level (Chen et al., 2015).…”

Section: Introductionmentioning

confidence: 99%

Population receptive field estimates for motion-defined stimuli

et al. 2019

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The processing of motion changes throughout the visual hierarchy, from spatially restricted ‘local motion’ in early visual cortex to more complex large-field ‘global motion’ at later stages. Here we used functional magnetic resonance imaging (fMRI) to examine spatially selective responses in these areas related to the processing of random-dot stimuli defined by differences in motion. We used population receptive field (pRF) analyses to map retinotopic cortex using bar stimuli comprising coherently moving dots. In the first experiment, we used three separate background conditions: no background dots (dot-defined bar-only), dots moving coherently in the opposite direction to the bar (kinetic boundary) and dots moving incoherently in random directions (global motion). Clear retinotopic maps were obtained for the bar-only and kinetic-boundary conditions across visual areas V1–V3 and in higher dorsal areas. For the global-motion condition, retinotopic maps were much weaker in early areas and became clear only in higher areas, consistent with the emergence of global-motion processing throughout the visual hierarchy. However, in a second experiment we demonstrate that this pattern is not specific to motion-defined stimuli, with very similar results for a transparent-motion stimulus and a bar defined by a static low-level property (dot size) that should have driven responses particularly in V1. We further exclude explanations based on stimulus visibility by demonstrating that the observed differences in pRF properties do not follow the ability of observers to localise or attend to these bar elements. Rather, our findings indicate that dorsal extrastriate retinotopic maps may primarily be determined by the visibility of the neural responses to the bar relative to the background response (i.e. neural signal-to-noise ratios) and suggests that claims about stimulus selectivity from pRF experiments must be interpreted with caution.

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Section: Introductionmentioning

confidence: 99%

Population receptive field estimates for motion-defined stimuli

et al. 2019

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“…Whilst this was critical in testing specific hypotheses arising from evidence dependent on this assumption, for a wider interpretation of the coherent DMN role this assumption may be questioned. It may be that the total activity in the DMN remains stable, yet the pattern of activity across the network changes meaningfully, or that deactivation of the DMN may reflect greater engagement of inhibitory processes (Daselaar et al 2004;Humphreys et al 2014;Knapen et al 2018). Currently there are many possible explanations of the function of the DMN.…”

Section: Dmn Support?mentioning

confidence: 99%

A Network-level Test of the Role of the Co-activated Default Mode Network in Episodic Recall and Social Cognition

Jackson

Humphreys

Rice

et al. 2021

Preprint

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Resting-state network research is extremely influential, yet the functions of many networks remain unknown. Hypotheses implicating the default mode network (DMN) in episodic memory and social cognition are highly popular. Univariate analyses and meta-analyses of these functions show activation in similar regions to the DMN. However, this does not necessitate the involvement of the coherent network in these functions. Here we formally test the role of the coherent DMN in episodic and social processing. As well as an episodic retrieval task, two independent datasets were employed to assess the breadth of social cognition; a person knowledge judgement and a theory of mind task. Independent component analysis separated each task dataset into coherent networks. For each, the core DMN was identified through comparison to an a priori template and its relation to the task model was assessed. The DMN did not show greater activity in episodic or social tasks than in high-level baseline conditions. Thus, no evidence was found for the involvement of the coherent DMN in explicit episodic or social processing tasks. The networks responsible for these processes are described and the univariate findings considered in light of these findings. Implications for the functional significance of the DMN are considered.

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Population receptive field estimates for motion-defined stimuli

Hughes

Greenwood

Finlayson

et al. 2018

Preprint

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6The processing of motion changes throughout the visual hierarchy, from spatially restricted 'local 7 motion' in early visual cortex to more complex large-field 'global motion' at later stages. Here we 8 used functional magnetic resonance imaging (fMRI) to examine spatially selective responses in 9 these areas related to the processing of random-dot stimuli defined by differences in motion. We 10 used population receptive field (pRF) analyses to map retinotopic cortex using bar stimuli 11 comprising coherently moving dots. In the first experiment, we used three separate background 12 conditions: no background dots (dot-defined bar-only), dots moving coherently in the opposite 13 direction to the bar (kinetic boundary) and dots moving incoherently in random directions (global 14 motion). Clear retinotopic maps were obtained for the bar-only and kinetic-boundary conditions 15 across visual areas V1-V3 and in higher dorsal areas. For the global-motion condition, retinotopic 16 maps were much weaker in early areas and became clear only in higher areas, consistent with the 17 emergence of global-motion processing throughout the visual hierarchy. However, in a second 18 experiment we demonstrate that this pattern is not specific to motion-defined stimuli, with very 19 similar results for a transparent-motion stimulus and a bar defined by a static low-level property 20(dot size) that should have driven responses particularly in V1. We further exclude explanations 21 based on stimulus visibility by demonstrating that the observed differences in pRF properties do 22 not follow the ability of observers to localise or attend to these bar elements. Rather, our findings 23 indicate that dorsal extrastriate retinotopic maps may primarily be determined by the visibility of 24 the neural responses to the bar relative to the background response (i.e. neural signal-to-noise 25 ratios) and suggests that claims about stimulus selectivity from pRF experiments must be 26 interpreted with caution. 27

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Mapping the Dark Side: Visual Selectivity of Default Network Deactivations

Cited by 3 publications

References 27 publications

Population receptive field estimates for motion-defined stimuli

Population receptive field estimates for motion-defined stimuli

A Network-level Test of the Role of the Co-activated Default Mode Network in Episodic Recall and Social Cognition

Population receptive field estimates for motion-defined stimuli

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