g , what are the processing demands of a strawberry or a chair?)

g., what are the processing demands of a strawberry or a chair?). As such, their proposal does not easily predict or account for the big-small Selleckchem INCB018424 organization of this cortex. However, in the following section we suggest an alternative account of the object-size organization which shares a fundamental premise of the eccentricity-bias proposal, namely that there is a meaningful relationship between the organization of visual object responses and the large-scale eccentricity organization of early visual areas. How might object representations come to be differentiated by real-world

size in this object-responsive cortex? Here, we propose a possible account of how this organization emerged from a combination of size-dependent biases in perceptual input, and size-dependent biases in functional requirements for action. Our proposal derives from two core ideas regarding the goals of the visual system: (1) to efficiently represent systematic biases in the sensory input

(e.g., along shape, retinal size, curvature, etc, e.g., Attneave, 1954, Carlson et al., 2011 and Field, 1987), and (2) to facilitate action in the natural environment (Gibson, 1979; e.g., computing what effectors you use to interact with an object). Our account describes how these convergent pressures could give rise to object representations organized by real-world size in occipitotemporal PI3K inhibitor cortex. Although this account is speculative and will require future work for direct supporting evidence, it nevertheless it provides a principled framework with testable predictions to guide future research. For observers in the world, there are certain geometric constraints that we suggest give rise to a systematic covariance between an object’s real-world size, shape, and experienced eccentricity. For example, although an observer can stand at any distance from an object, allowing the object

to project to any retinal size, some distances of interaction may be more frequent than others. A car at a typical viewing distance of 30 feet subtends a visual angle of ∼30 degrees, whereas a raisin held at an arm’s length subtends a much smaller visual angle of ∼1 degree, and would nearly have to touch the eye to subtend a visual angle of 30 degrees. Thus, over the course Vasopressin Receptor of natural viewing experience, in the lifetime or over evolutionary time, larger objects may tend to extend more peripherally on the retina than smaller objects (see also Konkle and Oliva, 2011). Additionally, we suggest that shape may be intrinsically correlated with object size based on gravitational and physical constraints of the world—e.g. smaller objects tend to be rounder and larger objects tend to be boxier (Konkle, 2011). These shape constraints manifest as systematic biases in low-level shape features such as curvature and spatial frequency content stimulating early visual areas.

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