A tidal wave of recent research purports to have discovered that higher-level states such as moods, action capabilities, and categorical knowledge can literally and directly affect how things look. Are these truly effects on perception, or might some instead reflect influences on judgment, memory, or response bias? Here, we exploited an infamous art-historical reasoning error (the so-called “El Greco fallacy”) to demonstrate that multiple alleged top-down effects (including effects of morality on lightness perception and effects of action capabilities on spatial perception) cannot truly be effects on perception. We suggest that this error may also contaminate several other varieties of top-down effects and that this discovery has implications for debates over the continuity (or lack thereof) of perception and cognition.

“Top-Down” Effects Where None Should Be Found The El Greco Fallacy in Perception Research

A chief goal of perception is to help us navigate our environment. According to a rich and ambitious theory of spatial perception, the visual system achieves this goal not by aiming to accurately depict the external world, but instead by actively distorting the environment's perceived spatial layout to bias action selection toward favorable outcomes. Scores of experimental results have supported this view-including, famously, a report that wearing a heavy backpack makes hills look steeper. This perspective portrays the visual system as unapologetically paternalistic: Backpacks make hills harder to climb, so vision steepens them to discourage ascent. The "paternalistic" theory of spatial perception has, understandably, attracted controversy; if true, it would radically revise our understanding of how and why we see. Here, this view is subjected to a kind and degree of scrutiny it has yet to face. After characterizing and motivating the case for paternalistic vision, I expose several unexplored defects in its theoretical framework, arguing that extant accounts of how and why spatial perception is ability-sensitive are deeply problematic and that perceptual phenomenology belies the view's claims. The paternalistic account of spatial perception not only isn't true-it couldn't be true, even if its empirical findings were accepted at face value.

/pdf/how-paternalistic-is-spatial-perception-why-wearing-a-heavy-2dt402shlm.pdf

How "Paternalistic" Is Spatial Perception? Why Wearing a Heavy Backpack Doesn't— and Couldn't—Make Hills Look Steeper

Experiments take place in a physical environment but also a social environment. Generalizability from experimental manipulations to more typical contexts may be limited by violations of ecological validity with respect to either the physical or the social environment. A replication and extension of a recent study (a blood glucose manipulation) was conducted to investigate the effects of experimental demand (a social artifact) on participant behaviors judging the geographical slant of a large-scale outdoor hill. Three different assessments of experimental demand indicate that even when the physical environment is naturalistic, and the goal of the main experimental manipulation was primarily concealed, artificial aspects of the social environment (such as an explicit requirement to wear a heavy backpack while estimating the slant of a hill) may still be primarily responsible for altered judgments of hill orientation.

/pdf/the-social-psychology-of-perception-experiments-hills-3587z829lh.pdf

The social psychology of perception experiments: hills, backpacks, glucose, and the problem of generalizability.

A central theme in the study of animal navigation has been the extent to which such navigation requires the formation of an internal representation of space, the so-called " cognitive map." Although its properties remain disputed, it is now generally accepted that a map-like representation exists in the brain, and neurobiological studies, conducted in tandem with behavioral investigations, have done much to elucidate the neural substrate of the map as it operates in two dimensions. However, to date little is known about how the map encodes real-world, three-dimensional space. Using recent neurobiological and behavioral fi ndings, this issue is explored here. It is argued that the navigational problems in three dimensions are qualitatively as well as quantitatively different from those in two dimensions, and evidence suggests that, perhaps for this reason, horizontal and vertical space are processed separately in the vertebrate brain. The possible adaptive consequences of such an anisotropic. © 2011 Massachusetts Institute of Technology and the Frankfurt Institute for Advanced Studies. All rights reserved.

Navigating in a three-dimensional world

The study of spatial cognition has provided considerable insight into how animals (including humans) navigate on the horizontal plane. However, the real world is three-dimensional, having a complex topography including both horizontal and vertical features, which presents additional challenges for representation and navigation. The present article reviews the emerging behavioral and neurobiological literature on spatial cognition in non-horizontal environments. We suggest that three-dimensional spaces are represented in a quasi-planar fashion, with space in the plane of locomotion being computed separately and represented differently from space in the orthogonal axis – a representational structure we have termed “bicoded.” We argue that the mammalian spatial representation in surface-travelling animals comprises a mosaic of these locally planar fragments, rather than a fully integrated volumetric map. More generally, this may be true even for species that can move freely in all three dimensions, such as birds and fish. We outline the evidence supporting this view, together with the adaptive advantages of such a scheme.

/pdf/navigating-in-a-three-dimensional-world-3ogt8wt32q.pdf

Palm boards are not action measures: an alternative to the two-systems theory of geographical slant perception.

https://www.swarthmore.edu/SocSci/fdurgin1/publications/DurginHajnalEtal2011.pdf

An imputed dissociation might be an artifact: Further evidence for the generalizability of the observations of Durgin et al. 2010

Whereas maps typically depict the two-dimensional layout of an environment, the vertical dimension is generally encountered only directly The possible importance of inclines as an orienting landmark in the environment (Nardi & Bingman, 2009), as well as the energetic significance of hills (Kammann, 1967; Proffitt, Bhalla, Gossweiler & Midgett, 1995) suggests that detailed memory of this aspect of the environment might be quite useful for navigation and route planning Geographical slant refers to surface slant relative to horizontal (Sedgwick, 1986) Previous studies of memory for geographical slant have focused primarily on newly-observed outdoor surfaces (Creem & Proffit, 1998) or on small indoor surfaces (Haun, Allen & Wedell, 2005), and each has reported biases in memory using both verbal and manual estimates Creem and Proffitt reported evidence of additional exaggeration in memory, whereas Haun et al reported a categorical bias toward 45° for both types of measure What has not been investigated experimentally is whether extremely familiar locomotor surfaces (eg, paths frequently taken in daily life) are subject to similar memory distortions

We sought to assess the precision of the information in memory about the geographical slant of a familiar environment (a small college campus) Our principal question is not one of representational accuracy It is well documented that geographical slant is overestimated (Kammann, 1967; Li & Durgin, 2010; Proffitt, Bhalla, Gossweiller & Midgett, 1995; Ross, 1974) Rather, our question is of representational precision The distinction between accuracy and precision is fundamental to measurement Precision is usually measured in terms of variability, or uncertainty, whereas accuracy is measured in terms of signed error or bias If one's perception of a hill is consistent, but highly biased, accuracy could be poor even while precision is good In fact, precise coding is more crucial than accurate coding for controlling action because, so long as actions and perceptions are coded in the same scale, actions themselves can be accurate (ie, effective) without the representations that guide them being veridical This allows action control to be able to adapt to distorted visual input, such as adaptation to wedge prisms that offset the perceived location of a target to the left When wearing such prisms, skilled reaching to grasp an object quickly adapts so that although the object still appears to be displaced (eg, to the left of one's midline) ballistic reaching becomes successful because one's proprioception of hand position comes to be shifted as well (Harris, 1980) So long as there is opportunity for calibration of action to visual experience, the success of action control depends on the precision rather than the accuracy of the perception A recent theoretical account of the exaggeration of geographical slant argues that angular perceptual variables are systematically biased (coded on an expanded scale) in order to retain greater coding precision (Durgin & Li, 2011)

For similar reasons, memory representations of surface layout ought to be most informative if they are scaled similarly to perception Moreover, the precision of such memory representations is of particular interest One would expect that estimates from newly-formed memories would be more variable (less precise) than those from perception and thus more open to categorical bias That is, judgmental biases have greater impact on estimates when estimate uncertainty is high (precision is low) But memory variability might decline to something quite close to the limits available in perception for familiar hills Indeed, given that a familiar slope might have been observed from many different perspectives, it is possible that a memory representation of a familiar surface could be even richer than that obtained by perceptual experience from a single vantage point On a small campus with a single dining hall, students may become experts not only at 2D route knowledge, but also at knowing the apparent 3D shape of the terrain they are frequently traversing

Haun et al (2005) proposed that memory errors in slant judgments might be due to categorical distortions and biases For example, memory for position is biased toward categorical locations (eg, Engbretson & Huttenlocher, 1996; Huttenlocher, Hedges & Duncan, 1991) and memory for angles (Fisher, 1968), graphs and figures also show systematic distortion (Tversky & Schiano, 1989) so that errors in slant memory may be quite general But one might nonetheless expect that highly familiar surfaces would be remembered as they actually appear to us

There have been many investigations of spatial memory biases for the 2D layout of real environments and maps (eg, Bahrick, 1979; Byrne, 1979; Tversky, 1981) However, most of these studies address novel layouts or long periods of storage The one study conducted by Creem and Proffitt (1998) for familiar hills (Experiment 3) was non-experimental in that all participants were tested only in the memory condition and were then compared to perceptual estimates previously collected by Proffitt et al (1995) under different circumstances We therefore sought to conduct a full experimental comparison of memory and perception for familiar slants

We used a small liberal arts college campus as the stimulus for our study Swarthmore College is situated in a variably inclined environment that provides a shared locomotor experience for its students There is a single dining hall, for example, that is commonly exited by ascending a somewhat steep extended path to the main academic area of the campus The campus is relatively small, so students are familiar with most of its paths But, how familiar are they with their slopes? That is, how precise are their memory representations and how similar are they to their perceptual experience?

We compared slant estimates obtained when students directly observed each of several paths with estimates obtained when other students recalled the same paths from memory To anticipate the results, students differentiated the various slopes of the tested paths equally well both in perception and in memory and there were no salient differences between estimates made from memory and from perception This suggests that incidental memory representations of the vertical dimension of a familiar locomotor environment can be quite rich


Perception and memory for familiar paths
The front of the campus of Swarthmore College features an extended broad hillside, of variable slope, at the center of which extends a tree-lined path (Magill Walk) leading up to the central college building (Parrish Hall) from the train station and town center We selected for study five well-travelled campus paths in this region of campus ranging from nearly flat (05°) to the steepest extended section of path (86°) in this part of campus Images of the steeper paths, and the locations of all the tested paths are illustrated in Figure 1



Figure 1

The locations of the five slanted paths used in the study on a campus map “Routes” refers to the 5 different orders used in both the perception condition and in the memory condition Below, the three steeper paths are shown in frontal 

/pdf/humans-have-precise-knowledge-of-familiar-geographical-3lua6mvo0r.pdf

Anthony Stigliani

Papers

Palm boards are not action measures: an alternative to the two-systems theory of geographical slant perception.

An imputed dissociation might be an artifact: Further evidence for the generalizability of the observations of Durgin et al. 2010

Humans have precise knowledge of familiar geographical slants.

How Accurate is Memory for Familiar Slope