Posterior Parietal Mechanisms of Visual Attention

Constantinidis, Christos

doi:10.1515/revneuro.2006.17.4.415

Cited by 32 publications

(29 citation statements)

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“…Although few studies have examined whether spatial maps exist in PFC under passive conditions, two nearby frontal areas, the frontal and supplementary eye fields, are both topologically connected to areas in visual cortex (Schall et al, 1993(Schall et al, , 1995, implying that, at a minimum, spatial maps are innately present within certain segments of the frontal cortex. These results are consistent with the known role that both areas (particularly the PPC) play in spatial processing (Colby and Goldberg, 1999;Constantinidis, 2006;Bisley and Goldberg, 2010).…”

Section: Innate or Context-dependent Feature Mapssupporting

confidence: 88%

Mnemonic Encoding and Cortical Organization in Parietal and Prefrontal Cortices

2017

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Persistent activity within the frontoparietal network is consistently observed during tasks that require working memory. However, the neural circuit mechanisms underlying persistent neuronal encoding within this network remain unresolved. Here, we ask how neural circuits support persistent activity by examining population recordings from posterior parietal (PPC) and prefrontal (PFC) cortices in two male monkeys that performed spatial and motion direction-based tasks that required working memory. While spatially selective persistent activity was observed in both areas, robust selective persistent activity for motion direction was only observed in PFC. Crucially, we find that this difference between mnemonic encoding in PPC and PFC is associated with the presence of functional clustering: PPC and PFC neurons up to ϳ700 m apart preferred similar spatial locations, and PFC neurons up to ϳ700 m apart preferred similar motion directions. In contrast, motion-direction tuning similarity between nearby PPC neurons was much weaker and decayed rapidly beyond ϳ200 m. We also observed a similar association between persistent activity and functional clustering in trained recurrent neural network models embedded with a columnar topology. These results suggest that functional clustering facilitates mnemonic encoding of sensory information.

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Section: Innate or Context-dependent Feature Mapssupporting

confidence: 88%

Mnemonic Encoding and Cortical Organization in Parietal and Prefrontal Cortices

2017

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“…Previous studies investigating the response to emotional distraction have also identified the recruitment of frontal, parietal and cingulate cortex (Bishop et al, 2004;Blair et al, 2007;Etkin et al, 2006;Mitchell et al 2007;Vuilleumier, et al, 2001). However, to our knowledge, no previous work has investigated the effect of distracter visibility on target processing; though related work has shown the increased recruitment of frontal and parietal areas in response to stimuli of increased visual salience (Constantinidis, 2006;Gottlieb et al, 1998;Indovina & Macaluso, 2006). Also, very little work has directly compared the impact of increasing distracter salience nonemotionally and emotionally within the same study (Compton et al 2003).…”

Section: Discussionmentioning

confidence: 96%

Common regions of dorsal anterior cingulate and prefrontal–parietal cortices provide attentional control of distracters varying in emotionality and visibility

et al. 2007

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Top-down attentional control is necessary to ensure successful task performance in the presence of distracters. Lateral prefrontal cortex, parietal cortex and anterior cingulate cortex have been previously implicated in top-down attentional control. However, it is unclear whether these regions are engaged independent of distracter type or whether, as has been suggested for anterior cingulate cortex, different regions provide attentional control over emotional versus other forms of salient distracter. In the current task, subjects viewed targets that were preceded by distracters that varied in both emotionality and visibility. We found that behaviorally, the presence of preceding distracters significantly interfered with target judgment. At the neural level, increases in the emotional and visual saliency of distracters were both associated with increased activity in proximal regions of prefrontal, parietal and cingulate cortex. Moreover, a conjunction analysis indicated considerable overlap in the regions of prefrontal, parietal cortex and anterior cingulate cortex responding to distracters of increased emotionality and visibility.

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“…interest PPC has received in the context of the control of spatial attention (Steinmetz and Constantinidis 1995;Gottlieb et al 1998;Colby and Goldberg 1999;Constantinidis andSteinmetz 2001, 2005;Corbetta and Shulman 2002;Goldberg 2003, 2006;Constantinidis 2006), we are the first to show how single cells in this brain area pool visual information across their receptive fields. Our results bear important implications for attention models of single-unit responses in the parietal cortex (cf., Ghose and Maunsell 2008;Ghose 2009).…”

Section: Discussionmentioning

confidence: 70%

“…However, when attention is directed towards these stimuli the winner phase of the response to such a pair of stimuli is shifted towards an AVR algorithm. The demonstrated max-behavior of area 7a neurons, which turned out to be irrespective of attention, could reflect this brain region's role in the integration of bottom-up attention for salient stimuli (Constantinidis andSteinmetz 2001, 2005).…”

Section: Discussionmentioning

confidence: 97%

“…For instance, parietal neurons have been shown to express the presence of a behaviorally relevant or perceptually salient stimulus embedded among distracter stimuli (Kusunoki et al 2000;Constantinidis andSteinmetz 2001, 2005;Goldberg 2003, 2006;Ipata et al 2009). In these studies, the neuronal responses were heavily biased by attention (either bottom-up or top-down) and they are therefore not very informative about the algorithm of unbiased spatial summation.…”

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confidence: 99%

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Spatial summation in macaque parietal area 7a follows a winner-take-all rule

Oleksiak

Klink

Postma

et al. 2011

Journal of Neurophysiology

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While neurons in posterior parietal cortex have been found to signal the presence of a salient stimulus among multiple items in a display, spatial summation within their receptive field in the absence of an attentional bias has never been investigated. This information, however, is indispensable when one investigates the mechanisms of spatial attention and competition between multiple visual objects. To examine the spatial summation rule in parietal area 7a neurons, we trained rhesus monkeys to fixate on a central cross while two identical stimuli were briefly displayed in a neuron's receptive field. The response to a pair of dots was compared with the responses to the same dots when they were presented individually. The scaling and power parameters of a generalized summation algorithm varied greatly, both across neurons and across combinations of stimulus locations. However, the averaged response of the recorded population of 7a neurons was consistent with a winner-take-all rule for spatial summation. A control experiment where a monkey covertly attended to both stimuli simultaneously suggests that attention introduces additional competition by facilitating the less optimal stimulus. Thus an averaging stage is introduced between ∼ 200 and 300 ms of the response to a pair of stimuli. In short, the summation algorithm over the population of area 7a neurons carries the signature of a winner-take-all operation, with spatial attention possibly influencing the temporal dynamics of stimulus competition, that is the moment that the "winner" takes "victory" over the "loser" stimulus.

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Posterior Parietal Mechanisms of Visual Attention

Cited by 32 publications

References 0 publications

Mnemonic Encoding and Cortical Organization in Parietal and Prefrontal Cortices

Mnemonic Encoding and Cortical Organization in Parietal and Prefrontal Cortices

Common regions of dorsal anterior cingulate and prefrontal–parietal cortices provide attentional control of distracters varying in emotionality and visibility

Spatial summation in macaque parietal area 7a follows a winner-take-all rule

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