Haptically straight lines

In this research, we set out to investigate haptically perceived space. Large deviations with respect to physical space have already been shown to exist. Here, research on haptic space is continued by investigating straight lines constructed by touch. In four experiments, subjects were asked to produce straight lines between two reference markers that were in the horizontal plane at a fixed distance from each other. Each experiment corresponded to a different task: two different interpolation tasks, an intersection task, and a pointing task. Straight lines had an orientation that was approximately frontoparallel. Subjects used both hands; manipulation was unrestricted. Although we found considerable differences between observers, the overall pattern of results showed that haptically straight lines were generally curved away from the observer. However, in one of the interpolation tasks they corresponded to physically straight lines. In addition, the pointing task generally produced larger deviations than the other three tasks. Taken together, the results show that there is no unique definition of the straight line, a conclusion that questions the viability of the concept of haptic space.     

Doggone affordances: Canine perception of affordances for reaching

Performing any behavior requires perceiving affordances—whether and how that behavior can be performed. Perception of affordances exhibits action scaling—choices about when to transition between two different modes of behavior reflect the fit between action capabilities and environmental properties. The boundary between distances that are perceived to be reachable with an arm-only reach and those that are perceived to be reachable with an arm-plus-torso reach occurs at farther distances for long-armed than for short-armed people, but at the same ratio of object-distance-to-arm length for both groups. To the extent that perception of affordances is supported by detection of invariant stimulation patterns, perception of a given affordance ought to exhibit action scaling regardless of species. We investigated the heights at which dogs chose to transition from reaching with the head only to rearing (i.e., reaching with the head plus torso). This transition occurred at a taller height for tall than for short dogs, but at the same ratio of shoulder-height-to-treat-height for both groups. The results demonstrate a similarity in perception of affordances across species and suggest that perception of affordances is supported by detection of lawfully structured stimulation patterns that may be invariant across species.     

Haptically perceiving the distances reachable with hand-held objects

Nine experiments are reported on the ability of people to perceive the distances reachable with hand-held rods that they could wield by movements about the wrist but not see. An observed linear relation between perceived and actual reaching distances with the rods held at one end was found to be unaffected by the density of the rods, the direction relative to the body in which they were wielded, and the frequency at which they were wielded. Manipulating (a) the position of an attached weight on an otherwise uniformly dense rod and (b) where a rod was grasped revealed that perceived reaching distance was governed by the principal moment(s) of inertia (I) of the hand-rod system about the axis of rotation. This dependency on moment of inertia (I) was found to hold even when the reaching distance was limited to the length of rod extending beyond an intermediate grasp. An account is given of the haptic subsystem (hand-muscles-joints-nerves) as a smart perceptual instrument in the Runeson (1977) sense, characterizable by an operator equation in which one operator functionally diagonalizes the inertia and strain tensors. Attunement to the invariants of the inertia tensor over major physical transformations may be the defining property of the haptic subsystem. This property is discussed from the Gibsonian (ecological) perspectives of information as invariants over transformations and of intentions as extraordinary constraints on natural law.     

Visual object affordances: object orientation

Five experiments systematically investigated whether orientation is a visual object property that affords action. The primary aim was to establish the existence of a pure physical affordance (PPA) of object orientation, independent of any semantic object-action associations or visually salient areas towards which visual attention might be biased. Taken together, the data from these experiments suggest that firstly PPAs of object orientation do exist, and secondly, the behavioural effects that reveal them are larger and more robust when the object appears to be graspable, and is oriented in depth (rather than just frontally) such that its leading edge appears to point outwards in space towards a particular hand of the viewer.     

Artifacts and affordances

What are the affordances of artifacts? One view is that the affordances of artifacts, just as the affordances of natural objects, pertain to possible ways in which they can be manipulated (e.g., a computer keyboard affords grasping). Another view maintains that, given that artifacts are sociocultural objects, their affordances pertain primarily to their culturally-derived function (e.g., a computer keyboard affords typing). Whereas some have tried to provide a unifying notion of affordance to capture both aspects, here I argue that they should be kept separate. In this paper, I introduce a distinction between standard affordances, which concern the function of artifacts, and ad-hoc affordances, which refer to how artifacts are manipulated. I then argue for the neuropsychological plausibility of such a distinction, linking it to the dissociation between function knowledge and manipulation knowledge. Finally, I defend the equal status of these forms of knowledge and, hence, of standard and ad-hoc affordances, and I show that this has some implications for the debate on the role of motor processes in the conceptual knowledge of artifacts.

     

Grasping the pain: Motor resonance with dangerous affordances

Two experiments, one on school-aged children and one on adults, explored the mechanisms underlying responses to an image prime (hand vs. control object) followed by graspable objects that were, in certain cases, dangerous. Participants were presented with different primes (a male, a female and a robotic grasping-hand; a male and a female static-hand; a control stimulus) and objects representing two risk levels (neutral and dangerous). The task required that a natural/artifact categorization task be performed by pressing different keys. In both adults and children graspable objects activated a facilitating motor response, while dangerous objects evoked aversive affordances, generating an interference-effect. Both children and adults were sensitive to the distinction between biological and non-biological hands, however detailed resonant mechanisms related to the hand-prime gender emerged only in adults. Implications for how the concept of “dangerous object” develops and the relationship between resonant mechanisms and perception of danger are discussed.     

Haptically Perceiving the Length of One Rod by Means of Another

Two experiments examined perception of the extent of a target rod that is contacted and wielded by a second probe rod. The equations that define the dynamics of the probe-target system suggest a higher order moment of inertia as the relevant perceptual variable. The particular inertial term implicates parameters of both the target and probe rod. Experiment 1 manipulated the inertia of the target rod and Experiment 2 manipulated the inertia of the probe rod. In both experiments, perceived length was a function of the complex inertial term. Results were discussed in terms of haptic perception at a distance, the equivalence of inert and neural appendages, and the scaling of perceived to actual variables.     

Emotion regulation choice: the role of environmental affordances

Which emotion regulation strategy one uses in a given context can have profound affective, cognitive, and social consequences. It is therefore important to understand the determinants of emotion regulation choice. Many prior studies have examined person-specific, internal determinants of emotion regulation choice. Recently, it has become clear that external variables that are properties of the stimulus can also influence emotion regulation choice. In the present research, we consider whether reappraisal affordances, defined as the opportunities for re-interpretation of a stimulus that are inherent in that stimulus, can shape individuals’ emotion regulation choices. We show that reappraisal affordances have stability across people and across time (Study 1), and are confounded with emotional intensity for a standardised set of picture stimuli (Study 2). Since emotional intensity has been shown to drive emotion regulation choice, we construct a context in which emotional intensity is separable from reappraisal affordances (Study 3) and use this context to show that reappraisal affordances powerfully influence emotion regulation choice even when emotional intensity and discrete emotions are taken into account (Study 4).     

Direct perception of action-scaled affordances: the shrinking gap problem

The aim of this study was to investigate the perception of possibilities for action (i.e., affordances) that depend on one's movement capabilities, and more specifically, the passability of a shrinking gap between converging obstacles. We introduce a new optical invariant that specifies in intrinsic units the minimum locomotor speed needed to safely pass through a shrinking gap. Detecting this information during self-motion requires recovering the component of the obstacles' local optical expansion attributable to obstacle motion, independent of self-motion. In principle, recovering the obstacle motion component could involve either visual or non-visual self-motion information. We investigated the visual and non-visual contributions in two experiments in which subjects walked through a virtual environment and made judgments about whether it was possible to pass through a shrinking gap. On a small percentage of trials, visual and non-visual self-motion information were independently manipulated by varying the speed with which subjects moved through the virtual environment. Comparisons of judgments on such catch trials with judgments on normal trials revealed both visual and non-visual contributions to the detection of information about minimum walking speed.     

Inviting affordances and agency

Recently several authors have suggested that affordances are not mere possibilities for action but can also invite behavior. This reconceptualization of affordances asks for a reconsideration of the ecological approach to agency. After a portrayal of the role of agency in ecological psychology, we draw upon phenomenology to reveal what it means for an agent to be invited by affordances. We sketch a dynamical model of the animal-environment relationship that aims to do justice to this analysis. In the model, agency is conceptualized as the capacity to modulate the coupling strength with the environment—the agent can influence to what extent he or she is influenced by the different invitations. This account of agency keeps us far from the Cartesian idea that the agent imposes behavior. Indeed, by modulating the coupling strength, the agent simply alters the dynamics of the animal-environment interactions and thus the behavior that emerges.     

Trusted strangers: social affordances for social cohesion

Phenomenology and the Cognitive Sciences - How could the paradigm shift towards enactive embodied cognitive science have implications for society and politics? Translating insights form enactive...     

Empathy and the responsiveness to social affordances

The direct perception theory of empathy claims that we can immediately experience a person’s state of mind. I can see for instance that my neighbour is angry with me in his bodily countenance. I develop a version of the direct perception theory of empathy which takes this perceptual capacity to depend upon recognising in what way the other person is responsive to the affordances the environment provides. By recognising which possibilities for action are relevant to a person, I can thereby understand something about the meaning they give to the world. I come to share something of their perspective on the world, and this allows me to grasp based on my perception of them something about their current state of mind. I argue that shared affect plays a central role in this perceptual capacity. Shared affect allows me to orient my attention to possibilities for action that matter to the other person. I end by briefly discuss the implications of this view of empathy for the disturbances in so-called “cognitive empathy” that are found in people diagnosed with autism spectrum disorder.     

Memory for the functional characteristics of climbing walls: perceiving affordances

In 2 experiments, differences in visual perception of climbing routes (route finding) between 7 expert climbers, 4 novices, and 9 inexperienced participants were studied. In both experiments, participants reproduced on a scale model the locations and orientations of 23 holds of a climbing wall. The results showed that the expert climbers recalled more information and recalled clusters of information and that they focused on the functional aspects of a climbing wall, whereas they neglected its structural features. Inexperienced participants did not recall such clustered information, and they reported almost exclusively the structural features of the holds. The perception of nested affordances and the expert climbers' neglect of details are discussed.     

Power influences the expression of Honesty-Humility: The power-exploitation affordances hypothesis

Across different experiments we show that individual differences in Honesty-Humility predict exploitation in economic games, and that this relation is moderated by situational power. Power was manipulated by comparing games in which allocators either had absolute power (dictator game), intermediate (delta game), or shared power (ultimatum game) over joint outcomes. We developed the power-exploitation affordances hypothesis that predicts that allocators with lower Honesty-Humility act more exploitative when they have absolute power than when their power is intermediate or shared. Additionally, we also tested these predictions for the actual earnings in these games. The results were generally supportive of our main hypotheses. Our findings contribute to understanding situational and personality effects on how individuals behave in positions of power (e.g., leaders).     

Conflict in the kitchen: Contextual modulation of responsiveness to affordances

Recently, human behavior has been considered the product of continuous interactions between perception, cognition and action in which “affordances” (action possibilities the environment has to offer) play an important role. Converging evidence suggests that multiple action possibilities simultaneously compete for further processing, while external and internal factors (e.g., incoming sensory information, predictions) bias this competition. In the present study we used a stop-task to investigate whether context is able to modulate the strength of the responsiveness to affordances. We therefore placed participants in an actual kitchen and workshop during electroencephalographic recordings. A faster response to context congruent objects demonstrated that the direct surrounding is able to affect responsiveness to affordances. In addition, when responses needed to be withheld, context congruent objects evoked greater response conflict as indicated by an enhanced N2 Event Related Potential (ERP) component.     

Dissociating object-based and space-based affordances

In what we term the orientation effect, faster spatial responses are made to the corresponding task irrelevant orientation of an object. We ask how this effect relates to object affordances, how attention may be involved, and how the effect relates to the better understood Simon effect. Two separate stimulus-response compatibility effects (an orientation effect and a Simon effect) were observed when spatial responses were made to photographs of objects whose orientation and location had been simultaneously manipulated. When attentional demands were high these separate effects were found using hand responses and foot responses, suggesting an abstract rather than specific coding of object affordances. However, when attentional demands were low only the Simon effect was observed, suggesting that, in order to obtain the orientation effect, objects must be represented at the level of an object.     

Perceiving affordances for joint actions

Two individuals acting together to achieve a shared goal often have an emergent set of afforded behavioral possibilities that may not easily reduce to either acting alone. In a series of experiments we examined the critical boundaries for transitions in behavior for individuals walking through an aperture alone or alongside another actor as a dyad. Results from experiment 1 indicated that an intrinsically scaled critical boundary for behavioral transitions was different in individuals than in dyads performing a similar task. Experiment 2 demonstrated that observers are perceptually sensitive to the difference in action parameters for the dyad, while still maintaining perceptual sensitivity about the boundaries of action relative to individuals. In experiment 3, we determined that observers' perception of critical action boundaries for individuals and dyads has a similar informational basis (eye-height scaling). In experiment 4, we demonstrated that observers were able to perceive critical action boundaries for other dyads independently of membership. Together, these results suggest that individuals are sensitive to the affordances related to a joint action, and that this process may not entirely reduce to the perception of the affordances for each individual.     

Affordances can invite behavior: Reconsidering the relationship between affordances and agency

The concept of agency has been central to ecological approaches to psychology. Gibson, one of the founders of this movement, made room for this concept by arguing against the mechanistic conceptions in psychology. In his view, the environment is not a collection of causes that pushes the animal around, but consist of action possibilities, which he coined affordances. In making their way in the world, animals regulate their behavior with respect to these possibilities. Reed later developed this ecological conception of agency, following Gibson in conceiving of affordances as action possibilities. However, drawing upon industrial design, architecture, and phenomenology, we argue that affordances are not mere action possibilities but that they can also invite behavior. We suggest a mutualist perspective on invitations, suggesting that they depend on the animal-environment relationship in multiple dimensions. The implications of this new conception of affordances for the ecological account of agency are explored.     

Object concepts and action: extracting affordances from objects parts

Two experiments with a part-generation task show that rated salience and production order of parts in artifacts are first predicted by their relevance for canonical actions, but also that they vary, depending on the current situation. In three further experiments participants read sentences describing actions (e.g., 'The woman shares the orange') followed by objects' parts from which it was easy or not to extract affordances (e.g., 'slice' vs. 'pulp'). They had to perform a part verification task or to evaluate whether or not the combination made sense. Parts from which it was easy to derive affordances were processed earlier and the combination was evaluated as the one which made more sense. Overall, results support the view that sensory-motor simulations underlie conceptualization and that concepts are action-based.     

Selves creating stories creating selves: a process model of self-development.

This article is focused on the growing empirical emphasis on connections between narrative and self-development. The authors propose a process model of self-development in which storytelling is at the heart of both stability and change in the self. Specifically, we focus on how situated stories help develop and maintain the self with reciprocal impacts on enduring aspects of self, specifically self-concept and the life story. This article emphasizes the research that has shown how autobiographical stories affect the self and provides a direction for future work to maximize the potential of narrative approaches to studying processes of self-development.