Intraparietal regions play a material general role in working memory: Evidence supporting an internal attentional role

Killebrew, Kyle; Mruczek, Ryan E. B.; Berryhill, Marian E.

doi:10.1016/j.neuropsychologia.2015.04.032

Cited by 12 publications

(10 citation statements)

References 94 publications

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“…A color and luminance varying flickering checkerboard stimulus was used to perform standard retinotopic mapping (Swisher, Halko, Merabet, McMains, and Somers 2007; Arcaro, McMains, Singer, and Kastner 2009; Killebrew, Mruczek and Berryhill 2015). Participants performed 8 runs of polar angle mapping and 2 runs of eccentricity mapping.…”

Section: Methodsmentioning

confidence: 99%

Decoding information about dynamically occluded objects in visual cortex

Erlikhman

Caplovitz

2017

NeuroImage

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During dynamic occlusion, an object passes behind an occluding surface and then later reappears. Even when completely occluded from view, such objects are experienced as continuing to exist or persist behind the occluder, even though they are no longer visible. The contents and neural basis of this persistent representation remain poorly understood. Questions remain as to whether there is information maintained about the object itself (i.e. its shape or identity) or, non-object-specific information such as its position or velocity as it is tracked behind an occluder as well as which areas of visual cortex represent such information. Recent studies have found that early visual cortex is activated by “invisible” objects during visual imagery and by unstimulated regions along the path of apparent motion, suggesting that some properties of dynamically occluded objects may also be neurally represented in early visual cortex. We applied functional magnetic resonance imaging in human subjects to examine the representation of information within visual cortex during dynamic occlusion. For gradually occluded, but not for instantly disappearing objects, there was an increase in activity in early visual cortex (V1, V2, and V3). This activity was spatially-specific, corresponding to the occluded location in the visual field. However, the activity did not encode enough information about object identity to discriminate between different kinds of occluded objects (circles vs. stars) using MVPA. In contrast, object identity could be decoded in spatially-specific subregions of higher-order, topographically organized areas such as ventral, lateral, and temporal occipital areas (VO, LO, and TO) as well as the functionally defined LOC and hMT+. These results suggest that early visual cortex may represent the dynamically occluded object’s position or motion path, while later visual areas represent object-specific information.

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Section: Methodsmentioning

confidence: 99%

Decoding information about dynamically occluded objects in visual cortex

Erlikhman

Caplovitz

2017

NeuroImage

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“…5A–B; Chafee & Goldman-Rakic, 1998; Gnadt & Andersen, 1988). While spatial working memory function has also been demonstrated in human IPS (Courtney, Ungerleider, Keil, & Haxby, 1996; Jonides, et al, 1993; Killebrew, et al, 2015; Schluppeck, et al, 2006; Sheremata, et al, 2010), the posterior IPS regions, possibly including IPS1/2, appear to be one, if not the, major hub for working memory more generally in the human brain. This is best exemplified by the seminal work of Todd and Marois (2004).…”

Section: A Hypothesis On Brain Adaptations For the ‘Human Toolmaker’mentioning

confidence: 95%

“…For example, both in humans and monkeys, these IPS regions show activity related to spatial attention (Colby & Goldberg, 1999; Lauritzen, D’Esposito, Heeger, & Silver, 2009; Silver, et al, 2005; Szczepanski, et al, 2010), saccadic eye movements (Konen & Kastner, 2008b; Snyder, Batista, & Andersen, 2000), working memory (Gnadt & Andersen, 1988; Killebrew, Mruczek, & Berryhill, 2015; Schluppeck, Curtis, Glimcher, & Heeger, 2006; Sheremata, Bettencourt, & Somers, 2010), and object stimuli (Janssen, Srivastava, Ombelet, & Orban, 2008; Konen & Kastner, 2008a; Mruczek, et al, 2013; Sereno & Maunsell, 1998), as will be elaborated in the next section. Additionally, human IPS2 and the ventral portion of macaque LIP show similar topographic representations of visual space relative to more posterior regions (Arcaro, et al, 2011; Ben Hamed, et al, 2001).…”

Section: Functional Response Properties: Effector Specificity and Mulmentioning

confidence: 99%

A brief comparative review of primate posterior parietal cortex: A novel hypothesis on the human toolmaker

et al. 2017

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The primate visual system contains two major cortical pathways: a ventral-temporal pathway that has been associated with object processing and recognition, and a dorsal-parietal pathway that has been associated with spatial processing and action guidance. Our understanding of the role of the dorsal pathway, in particular, has greatly evolved within the framework of the two-pathway hypothesis since its original conception. Here, we present a comparative review of the primate dorsal pathway in humans and monkeys based on electrophysiological, neuroimaging, neuropsychological, and neuroanatomical studies. We consider similarities and differences across species in terms of the topographic representation of visual space; specificity for eye, reaching, or grasping movements; multi-modal response properties; and the representation of objects and tools. We also review the relative anatomical location of functionally- and topographically-defined regions of the posterior parietal cortex. An emerging theme from this comparative analysis is that non-spatial information is represented to a greater degree, and with increased complexity, in the human dorsal visual system. We propose that non-spatial information in the primate parietal cortex contributes to the perception-to-action system aimed at manipulating objects in peripersonal space. In humans, this network has expanded in multiple ways, including the development of a dorsal object vision system mirroring the complexity of the ventral stream, the integration of object information with parietal working memory systems, and the emergence of tool-specific object representations in the anterior intraparietal sulcus and regions of the inferior parietal lobe. We propose that these evolutionary changes have enabled the emergence of human-specific behaviors, such as the sophisticated use of tools.

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“…To bridge these two literatures, we recently measured fMRI while applying a CDA paradigm. We found that the IPS represents contralaterally presented items in VWM, but that VWM capacity limits did not differ when attending to one or both visual hemifields [23]. These findings provide converging neural evidence that VWM maintenance related processes contribute to VWM capacity limitations.…”

Section: Introductionmentioning

confidence: 78%

Induced and Evoked Human Electrophysiological Correlates of Visual Working Memory Set-Size Effects at Encoding

et al. 2016

Self Cite

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The ability to encode, store, and retrieve visually presented objects is referred to as visual working memory (VWM). Although crucial for many cognitive processes, previous research reveals that VWM strictly capacity limited. This capacity limitation is behaviorally observable in the set size effect: the ability to successfully report items in VWM asymptotes at a small number of items. Research into the neural correlates of set size effects and VWM capacity limits in general largely focus on the maintenance period of VWM. However, we previously reported that neural resources allocated to individual items during VWM encoding correspond to successful VWM performance. Here we expand on those findings by investigating neural correlates of set size during VWM encoding. We hypothesized that neural signatures of encoding-related VWM capacity limitations should be differentiable as a function of set size. We tested our hypothesis using High Density Electroencephalography (HD-EEG) to analyze frequency components evoked by flickering target items in VWM displays of set size 2 or 4. We found that set size modulated the amplitude of the 1st and 2nd harmonic frequencies evoked during successful VWM encoding across frontal and occipital-parietal electrodes. Frontal sites exhibited the most robust effects for the 2nd harmonic (set size 2 > set size 4). Additionally, we found a set-size effect on the induced power of delta-band (1–4 Hz) activity (set size 2 > set size 4). These results are consistent with a capacity limited VWM resource at encoding that is distributed across to-be-remembered items in a VWM display. This resource may work in conjunction with a task-specific selection process that determines which items are to be encoded and which are to be ignored. These neural set size effects support the view that VWM capacity limitations begin with encoding related processes.

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Intraparietal regions play a material general role in working memory: Evidence supporting an internal attentional role

Cited by 12 publications

References 94 publications

Decoding information about dynamically occluded objects in visual cortex

Decoding information about dynamically occluded objects in visual cortex

A brief comparative review of primate posterior parietal cortex: A novel hypothesis on the human toolmaker

Induced and Evoked Human Electrophysiological Correlates of Visual Working Memory Set-Size Effects at Encoding

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