Interaction between Spatial and Feature Attention in Posterior Parietal Cortex

Abstract

Summary Lateral intraparietal (LIP) neurons encode a vast array of sensory and cognitive variables. Recently, we proposed that the flexibility of feature representations in LIP reflect the bottom-up integration of sensory signals, modulated by feature-based attention (FBA), from upstream feature-selective cortical neurons. Moreover, LIP activity is also strongly modulated by the position of space-based attention (SBA). However, the mechanisms by which SBA and FBA interact to facilitate the representation of task-relevant spatial and non-spatial features in LIP remain unclear. We recorded from LIP neurons during performance of a task which required monkeys to detect specific conjunctions of color, motion-direction, and stimulus position. Here we show that FBA and SBA potentiate each other’s effect in a manner consistent with attention gating the flow of visual information along the cortical visual pathway. Our results suggest that linear bottom-up integrative mechanisms allow LIP neurons to emphasize task-relevant spatial and non-spatial features.

Computing by Robust Transience: How the Fronto-Parietal Network Performs Sequential, Category-Based Decisions

“…Furthermore, our trained networks reproduce mixed category and match selectivity, which is evident in our neural data (Figure S2H–I) and other studies (Ibos and Freedman, 2014; Ibos and Freedman, 2016; Park et al, 2014; Rishel, 2013; Mante et al, 2013; Rigotti et al, 2013). This suggests that a large portion cortical neurons and model neurons participate in more than one computation.…”

“…First, the existence and abundance of mixed selectivity neurons (Ibos and Freedman, 2014; Ibos and Freedman, 2016; Mante et al, 2013; Park et al, 2014; Raposo et al, 2014; Rigotti et al, 2013; Rishel, 2013) and the time-varying selectivity for task-relevant variables at both single-neuron (Brody et al, 2003a; Jun et al, 2010; Shafi et al, 2007) and population levels (Machens, 2010; Crowe et al, 2010; Meyers et al, 2008; Wohrer et al, 2013) have sparked a debate on the dynamical nature of working memory (Druckmann and Chklovskii, 2012; Goldman, 2009; Sarma et al, 2016; Savin and Triesch, 2014; Singh and Eliasmith, 2006). Since the model captures all these features, it is possible now to pinpoint the working memory dynamics that give rise to these patterns of selectivity.…”

“…These models elucidated candidate mechanisms of delay-period persistent selectivity, but they are not designed to address the diversity or temporal variability in neural responses, which are apparent in neural data. In particular, the majority of neurons are responsive to multiple task variables (Raposo et al, 2014; Rigotti et al, 2013; Ibos and Freedman, 2014; Mante et al, 2013; Ibos and Freedman, 2016; Freedman and Assad, 2016) and neural encoding often shows baffling temporal variability (Brody et al, 2003a; Crowe et al, 2010; Jun et al, 2010; Shafi et al, 2007). To address these phenomena, recent studies considered an alternative hypothesis that information is distributed randomly within the neural network (Rigotti, et al 2010; Raposo et al, 2014).…”

Attentional Modulation of Neuronal Activity Depends on Neuronal Feature Selectivity

“…Some differences in timing of neuronal responses during spatial versus feature attention tasks have been observed [48, 50] but see [58]. However, most studies describe additive effects of spatial and feature attention and many suggest separate mechanisms [4, 51, 55]. Relationships between feature attention modulation and individual neuronal selectivity have only been explored in a handful of studies with somewhat conflicting results.…”

Dynamics of coherent activity between cortical areas defines a two-stage process of selective attention

“…This is particularly plausible given the presence of feature selective neurons, in LIP, e.g. cells with selective responses to differently orientated lines (9)(10)(11)(12). We have also recently shown that LIP contains two groups of neurons having distinctly different responses to the stimuli in our DMS task, which occur during different parts of the delay period between the stimulus pair (12).…”