Perceiving Potentiality: A Metaphysics for Affordances

Topoi - According to ecological psychology, animals perceive not just the qualities of things in their environment, but their affordances: in James Gibson’s words, ’what things furnish,...     

Collective Affordances

Abstract

This article develops an ecological framework for understanding collective action. This is contrasted with approaches familiar from the collective intentionality debate, which treat individuals (with collective intentions) as fundamental units of collective action. Instead, we turn to social ecological psychology and dynamical systems theory and argue that they provide a promising framework for understanding collectives as the central unit in collective action. However, we submit that these approaches do not yet appreciate enough the relevance of social identities for collective action. To analyze this aspect, we build on key insights from social identity theory and synthesize it with embodied and ecological accounts of perception and action. This results in the proposal of two new types of affordances. For an individual who enacts her “embodied social identity” of being a member of a particular collective, there can be what we call embodied social identity affordances. Moreover, when several individuals dynamically interact with each other against the background of their embodied social identities, this might lead to the emergence of a collective, which we understand as a dynamically constituted and ecologically situated perception-action system consisting of several individuals enacting relevant embodied social identity affordances. Building on previous work in social ecological psychology, we suggest that there can be genuine collective affordances, that is, affordances whose subject is not an individual, but a collective.     

Persons and Affordances

Abstract

Interdisciplinary interest in affordances is increasing. This paper is a philosophical contribution. The question is: Do persons offer affordances? Analysis of the concepts ‘person’ and ‘affordance’ supports an affirmative answer. On a widely accepted understanding of what persons are, persons exhibit many of the features typical of socionormative affordances. However, to understand persons as offering affordances requires, on the face of it, stretching traditional understandings of the concept of affordance: persons, in contrast to the organisms that partially constitute persons, do not seem to be available to perception. This and similar worries are responded to.     

Affordances and infant learning: A reply to Horowitz

We reply to three major points made by F. Horowitz (1983, Developmental Review, 3, 405–409) in her commentary on the ecological approach to infant knowing presented by E. Goldfield (1983, Developmental Review, 3, 371–404). We first clarify the relation between perceiving and acting from an ecological perspective, and distinguish between affordances as environmental properties scaled to the perceiver/performer and representations as mental structures. We then present a critique of the process of association offered by Horowitz as an explanation of infant learning. Association fails to specify the constraints on what is learned, while the ecological process of noticing affordances, presented by Goldfield, considers such constraints. We conclude by presenting operational criteria for measuring affordances and evidence that perception is scaled to the perceiver/performer.     

On Stoffregen's Definition of Affordances

Stoffregen (2003) has proposed a formal definition of affordances as emergent or relational properties of animal-environment systems. This definition contrasts with Turvey's (1992) formal definition of affordances as properties of the environment. In this commentary, my purpose is not to take sides on this issue but instead to bring to light what I believe to be a crucial flaw in Stoffregen's definition. Specifically, I show that Stoffregen's definition places no constraint on which relational or emergent properties legitimately deserve to be counted as affordances, thus allowing any relational property that can be predicated of an animal-environment system to be considered as an affordance. As such, Stoffregen's definition lacks any substantive linkage to the "opportunity for action" notion that has accounted for the scientific utility of the concept to date, a linkage I suggest should be preserved in any definition of affordances.     

Affordances after spinal cord injury

Spinal cord injury can cause cognitive impairments even when no cerebral lesion is appreciable. As patients are forced to explore the environment in a non-canonical position (i.e., seated on a wheelchair), a modified relation with space can explain motor-related cognitive differences compared to non-injured individuals. Peripersonal space is encoded in motor terms, that is, in relation to the representation of action abilities and is strictly related to the affordance of reachability. In turn, affordances, the action possibilities suggested by relevant properties of the environment, are related to the perceiver's peripersonal space and motor abilities. One might suppose that these motor-related cognitive abilities are compromised when an individual loses the ability to move. We shed light on this issue in 10 patients with paraplegia and 20 matched controls. All have been administered an affordances-related reachability judgement task adapted from Costantini, Ambrosini, Tieri, Sinigaglia, and Committeri (2010, Experimental Brain Research, 207, 95) and neuropsychological tests. Our findings demonstrate that patients and controls show the same level of accuracy in estimating the location of their peripersonal space boundaries, but only controls show the typical overestimation of reaching range. Secondly, patients show a higher variability in their judgements than controls. Importantly, this finding is related to the patients’ ability to perform everyday tasks. Finally, patients are not faster in making their judgements on reachability in peripersonal space, while controls are. Our results suggest that not moving freely or as usual in the environment impact decoding of action-related properties even when the upper limbs are not compromised.     

Social Affordances and Interaction II: Autism and the Affordances of the Human Environment

The interaction between informational support or task constraints and functional motor performance was explored using kinematic profiles of the arms and hands of 40 participants with and without multiple sclerosis (MS). Three functional tasks were performed under three conditions: impoverished (i.e., participants mimed the tasks), partial (i.e., participants mimed the tasks with a limited array of the objects normally used), and natural (i.e., participants performed the actual tasks). Results indicated that each of the three conditions elicited unique kinematic profiles. Movement time, maximum displacement, and velocity variability were significantly different among each of the three conditions. An ecological interpretation suggested that functional performance emerged from the interaction of the task demands of each condition and of the action capabilities of the participants. Participants with and without MS responded to the three conditions in similar ways, except that those with MS performed the tasks more slowly. We speculated that the slower performance was a function of the reduced and inconsistent action capabilities of the participants with MS.     

Perceiving Multiple Affordances for Objects

Researchers (Gilden &; Proffitt, 1989; Runeson &; Vedeler, 1993; Todd &; Warren, 1982) have tested Runeson's (1977) claim that the relation between a collision . . event's dynamics and kinematics might support perception of the relative mass of colliding objects. Results have been inconsistent; however, these studies employed computer-generated collisions as stimuli. The present research assessed observer's ability to report relative mass in the context of physical objects involved in physical collisions. The results indicate greater sensitivity to relative mass than had been found with animations-based studies. Implications of these data for the kinematic specification of dynamics (KSD) principle of dynamics perception (Runeson &; Frykholm, 1983) and a cue-heuristics theory of dynamics perception (Gilden &; Proffitt, 1989) are discussed.     

An Outline of a Theory of Affordances

The principle of auditory enhancement is a valuable extension of the theory of adaptive dispersion. However, neither the principle nor the theory has any bearing on what we perceive in speech. All perceptual objects, including those of speech, are abstract, amodal structures made available to cognition through one or more sensory modalities. A focus on the modalities or media of information transfer in speech perception diverts attention from two central and related aspects of speech function: perceptuomotor functional equivalence and imitation. Arguments and evidence from studies of lipreading, short-term memory, and infant behavior are put forward to support the postulation of an output unit, the phonetic gesture, at a level in the communication chain corresponding on the input side to the acoustic cue. The object of speech perception is then taken to be the amodal phonetic segment, a cohesive set of direct mappings between sound and gesture.     

Affordances,context and sociality

Affordances, i.e. the opportunity of actions offered by the environment, are one of the central research topics for the theoretical perspectives that view cognition as emerging from the interaction between the environment and the body. Being at the bridge between perception and action, affordances help to question a dichotomous view of perception and action. While Gibson’s view of affordances is mainly externalist, many contemporary approaches define affordances (and micro-affordances) as the product of long-term visuomotor associations in the brain. These studies have emphasized the fact that affordances are activated automatically, independently from the context and the previous intention to act: for example, affordances related to objects’ size would emerge even if the task does not require focusing on size. This emphasis on the automaticity of affordances has led to overlook their flexibility and contextual-dependency. In this contribution I will outline and discuss recent perspectives and evidence that reveal the flexibility and context-dependency of affordances, clarifying how they are modulated by the physical, cultural and social context. I will focus specifically on social affordances, i.e. on how perception of affordances might be influenced by the presence of multiple actors having different goals.

     

Affordances and the Nature of Perceptual Content

Abstract

According to John McDowell, representational perceptual content is conceptual through and through. This paper criticizes this view by claiming that there is a certain kind of representational and non‐conceptual perceptual content that is sensitive to bodily skills. After a brief introduction to McDowell’s position, Merleau‐Ponty’s notion of body schema and Gibson’s notion of affordance are presented. It is argued that affordances are constitutive of representational perceptual content, and that at least some affordances, the so‐called ‘conditional affordances’, are essentially related to the body schema. This means that the perceptual content depends upon the nature of the body schema. Since the body schema does not pertain to the domain that our conceptual faculties operate upon, it is argued that this kind of perceptual content cannot be conceptual. At least some of that content is representational, yet it cannot feature as non‐demonstrative conceptual content. It is argued that if it features as demonstrative conceptual content, it has to be captured by private concepts. Since McDowell’s theory does not allow for the existence of a private language, it is concluded that at least some representational perceptual content is non‐conceptual.     

Affordances as Properties of the Animal-Environment System

In this article, I argue that affordances are properties of the animal-environment system, that is, that they are emergent properties that do not inhere in either the environment or the animal. I critique and review the formal definition of affordance offered by Turvey (1992). Turvey defined affordances as properties of the environment; I discuss some consequences of this and argue that Turvey's strategy of grounding the definition of affordance in terms of dispositional properties is problematic. I also suggest that Turvey's definition of affordance may lead to problems for the specification and direct perception of affordances. Motivated by these problems, I propose a new definition of affordance, in which affordances are properties of the animal-environment system. This definition does not rely on the concept of dispositional properties and is consistent with direct perception.     

Gibson's Affordances and Turing's Theory of Computation

The concept of affordance is a central component of the ecological psychology of J. J. Gibson (1966, 1977, 1979/1986). Affordances are properties of the environment taken relative to an observer. Ecological theorists have developed formal models for the analysis of affordances. Models proposed by Shaw and Turvey (1981), Turvey (1992), and Greeno (1994) are described and evaluated, and another approach, using Turing's (1936-1937/1965) theory of computation, is outlined. Affordances are characterized as the configurations of Turing machines. It is shown that Turing's work provides a natural vehicle for exploring Gibson's ideas.     

Affordances matter in geographical slant perception

We argue that the experimental conditions in the Durgin et al. (2009) study were so different from those in Bhalla and Proffitt (1999) that the results of the former study cannot be generalized to the latter. The participants in the Durgin et al. study viewed a 2-m-long ramp; those in Bhalla and Proffitt viewed expansive hills. When drawing generalizations from one study to another, equating experimental conditions is always important; moreover, from an embodied perspective on perception, equating the opportunities for action also matters.     

Cognition as the Cooperative Appropriation of Affordances

Michaels (2000) expressed concerns about the implications of the notion of 2 visual systems (Milner &; Goodale, 1995) for ecological psychology. This leads her to suggest a decoupling of perception and action, by which action is separate from perception. It is suggested that although Michaels noted, on the one hand, that Milner and Goodale's approach to perception is a constructivist one, she mistakenly adopts their view that separates vision for perception from vision for action. An alternative position is presented, based on a recent article (Norman, in press), in which the parallels between the 2 visual systems, dorsal and ventral, and the 2 theoretical approaches, ecological and constructivist, are elucidated. According to this dual-process approach to perception, both systems are perceptual systems. The ecological-dorsal system is the system that picks up information about the ambient environment allowing the organism to negotiate it. It is suggested that this type of perception always processes the relevant information for action and that there is no need to sever the perception-action coupling. Ecological psychology and the 2 visual systems are quite compatible, and there is no need for concern.     

Social Affordances and Interaction I: Introduction

Recent extensions of the affordance concept to fundamental problems in the study of social knowing and interaction were the focus of one of the symposia at the Fifth International Conference on Event Perception and Action, at Miami University, Oxford, OH in July 1989. This article traces the history of ecological social psychology and reviews recent attempts to extend the application of the concept of affordance to the topics of social knowing and social interaction. Themes arising within three domains of contemporary ecological research are examined: (a) social perception research has stressed the direct perception of what other people afford the self and the perception of what other people are afforded in their transactions with the shared environment of surfaces, objects, places, and other persons; (b) in the study of social interaction, the emphasis recently has been on the processes of the perceiving and the assembling of social coordination, and also on the functions of social interaction in the acquisition of knowledge and behavioral competence; and (c) cultural practices, such as those involved in caregiver-infant interactions, appear to play a central role in organizing the shared focus of attention and in revealing and creating affordances for action and interaction. Some of the work described in this article appears in the current and subsequent issues of Ecological Psychology.     

Affordances and Events: Theory and Research

In replying to the commentaries, I focus on issues relating to theory, empirical practice (i.e., to how research on events and affordances has been conducted), and empirical research that I think is needed. I reiterate my argument that because they differ qualitatively, affordances might be perceived without prior or concurrent perception of the underlying events. I suggest that research on event perception might, in principle, inform research on the perception of affordances, but existing research has made no explicit attempt to do this. I conclude by stressing the need for new research and for exponents of event perception to identify a theoretical motivation, within ecological theory, for why events should be perceived.     

Affordances as constraints on the control of stance

In this article we present an ecological treatment of the control of stance by multi-segment organisms. We treat the organism as a black box, and the organism-environment interaction as a closed-loop system. We argue that different ways of controlling stance can have differing utility (affordances) for perception and action. We further argue that the affordances of a particular control strategy are in part determined by (a) the mechanical properties of the organism, (b) the mechanical properties of the surface on which stance takes place, and (c) the goals of behavior. Our conclusion is that the control of stance is based on, or constrained by, perception of the kinematic consequences, or affordances, of control actions. Finally, we argue that the relationship between affordances and constraints on control actions should be investigated using geometrical methods.     

Affordances in Interaction: The Case of Aikido

Our title can be read as trivially true, namely, that perceived affordances shape real-time interaction dynamics. A less trivial reading suggests that affordances themselves interact in a shared dyadic field, such that the number and quality of As and Bs affordances are dynamically coupled with bidirectional causality. In dance, martial arts, or team sports agents strategically comodulate each other's affordances while pursuing their aims. In Aikido, where agents try to break their opponents' balance, this trade-off globally approximates a zero-sum game—the better A's affordances are, the lousier B's affordances get. The agents are subject to ceaseless cross-causation in this shared field. They seek to obstruct their opponents' options while strategically enabling, augmenting, and sculpting their own by employing subtle perceptual manipulation skills, redirecting force, brinkmanship, and switching techniques opportunistically. To overcome static views, we conceptualize affordances as cascading and having fluid onsets; we also identify nested affordances in goal hierarchies and describe a spectrum of affordance functions. Ultimately, we suggest rethinking the ontology of affordances as being sensitive to dynamic engagements, hence defined relative to interpersonal emergence.