What and Where: Location-Dependent Feature Sensitivity as a Canonical Organizing Principle of the Visual System

Abstract

Traditionally, functional representations in early visual areas are conceived as retinotopic maps preserving ego-centric spatial location information while ensuring that other stimulus features are uniformly represented for all locations in space. Recent results challenge this framework of relatively independent encoding of location and features in the early visual system, emphasizing location-dependent feature sensitivities that reflect specialization of cortical circuits for different locations in visual space. Here we review the evidence for such location-specific encoding including: (1) systematic variation of functional properties within conventional retinotopic maps in the cortex; (2) novel periodic retinotopic transforms that dramatically illustrate the tight linkage of feature sensitivity, spatial location, and cortical circuitry; and (3) retinotopic biases in cortical areas, and groups of areas, that have been defined by their functional specializations. We propose that location-dependent feature sensitivity is a fundamental organizing principle of the visual system that achieves efficient representation of positional regularities in visual experience, and reflects the evolutionary selection of sensory and motor circuits to optimally represent behaviorally relevant information. Future studies are necessary to discover mechanisms underlying joint encoding of location and functional information, how this relates to behavior, emerges during development, and varies across species.

Bayesian interpolation for power laws in neural data analysis

“…For instance, attention is known to alter neural responses both at the single cell [35] and population levels [36,37]. It would thus be informative to study if the degree of smoothness of the stimulus-response relationship in a given recorded population is related to the degree of attention to the part of the scene that is retinotopically mapped to that population, and, from a broader perspective, other functional 18/28 non-uniformities that such mapping entails [38,39].…”

Self-organized emergence of modularity, hierarchy, and mirror reversals from competitive synaptic growth in a developmental model of the visual pathway

“…The scale and semantic content of features increases along the hierarchy. Areas in the early visual cortex such as V1, V2, V3, V4, and some areas in the lateral occipital cortex preserve the global topography of visual inputs to the retina [1, 2, 3, 4, 5, 6, 7]. This mapping of nearby locations on the retina to nearby regions of cortex, or retinotopy, is similar to the topographical mapping of inputs seen in other sensory cortices [8, 9, 10].…”

Development and Organization of the Retinal Orientation Selectivity Map

“…Previous studies focusing on direction selectivity challenged the notion that this computation is homogeneously organized in the retina and is instead organized in a map of optic flow axes in the mouse retina 3,4 . In fact, it is becoming increasingly evident that the mouse retina exhibits many region-specific maps for various anatomical and functional features 2,5,6 and that location-dependent feature decoders may reflect a fundamental organizing principle that most efficiently detects important aspects of the visual scene 7 . Even though orientation selectivity is such a fundamentally well studied visual computation, how this computation is organized in the retina is unknown.…”