Target-directed visual attention is a prerequisite for action-specific perception

Witt et al. (2008) have recently shown that golfers who putt with more success perceive the hole to be bigger than golfers who putt with less success. In three experiments, we systematically examined whether this phenomenon, labelled action-specific perception, depends on directing visual attention towards the action target. In Experiment 1 we replicated previously reported action-specific effects on perception in golf putting. In 3 and 4 we directly assessed whether action-specific effects on perception in golf putting are dependent on focusing visual attention on the target. To this end, the participants performed the putting task while visual attention towards the target was either completely withheld (Experiment 2) or divided over the target and other task-relevant objects (Experiment 3). No action-specific effects were found when visual attention towards the action target was occluded or partially diverted from the target. Together, our results provide evidence to suggest that focusing visual attention on the target while performing the action is a prerequisite for the emergence of action-specific perception.     

Action-specific effects in a social context: others' abilities influence perceived speed

According to the action-specific account of perception, perceivers see the environment relative to their ability to perform the intended action. For example, in a modified version of the computer game Pong, balls that were easier to block looked to be moving slower than balls that were more difficult to block (Witt & Sugovic, 2010). It is unknown, however, if perception can be influenced by another person's abilities. In the current experiment, we examined whether another person's ability to block a ball influenced the observer's perception of ball speed. Participants played and observed others play the modified version of Pong where the task was to successfully block the ball with paddles that varied in size, and both the actor and observer estimated the speed of the ball. The results showed that both judged the ball to be moving faster when it was harder to block. However, the same effect of difficulty on speed estimates was not found when observers watched a computer play, suggesting the effect is specific to people and not to the task. These studies suggest that the environment can be perceived relative to another person's abilities.     

The influence of anxiety on action-specific perception

Abstract

Recent empirical research suggests that performance modulates perception. For example, baseball players judge the ball to be bigger when performing well as compared to when performing less successfully. Yet, the underlying processes that mediate the emergence of action-specific effects on perception are still largely unknown. To this end, we aimed to examine the impact of anxiety on the action-specific influence on perception as anxiety has been shown to affect both performance and perception. Thirty participants threw darts at a circle-shaped target and were then asked to judge the size of the target. The task was performed under conditions of low and high anxiety. Results replicated previously reported action-specific effects on perception under levels of low anxiety. However, these effects vanished in the high anxiety condition. Results seem to suggest that anxiety has a direct influence on the relation between performance and perception. Attentional control theory is discussed to explain the current findings.     

The impact of visual illusions on perception, action planning, and motor performance

The present study extended recent research revealing that illusions can influence performance in golf putting (Witt, Linkenauger, & Proffitt Psychological Science, 23, 397–399, 2012), by exploring the potential mediating roles of attention and action planning. Glover and Dixon’s (Journal of Experimental Psychology. Human Perception and Performance, 27, 560–572, 2001) planning–control model suggests that both perceptual and movement-planning processes are prone to illusion-based bias. We therefore predicted that both the perception of target size and a measure of attentional control related to movement planning in golf putting (the quiet eye) would be influenced by the illusion. Moreover, as performance could not be corrected using online control (once the ball was struck), we predicted that these biases would also influence performance. We therefore proposed a three-stage process by which illusory context biases perceptual processes, which in turn bias subsequent attentional control related to movement planning, which in turn biases motor performance. Forty novice golfers completed an Ebbinghaus illusion putting task that was designed to manipulate their perceptions of target size, while quiet eye duration and performance (mean radial error) were measured. The results indicated that the illusion was effective in facilitating differences in perceived target size, with perceptually bigger holes promoting longer quiet eye durations and more accurate putting. Follow-up mediation analyses revealed that illusion-based differences in size perception partially mediated illusion-based differences in both quiet eye duration and performance. Moreover, the relationship between illusion-based differences in quiet eye duration and performance was also significant. Future research should further test this three-stage process of bias in other far-aiming tasks in which online control cannot be used.     

Does ease to block a ball affect perceived ball speed? Examination of alternative hypotheses

According to an action-specific account of perception, the perceived speed of a ball can be a function of the ease to block the ball. Balls that are easier to stop look like they are moving slower than balls that are more difficult to stop. This was recently demonstrated with a modified version of the classic computer game Pong (Witt & Sugovic, 2010). However, alternative explanations can also explain these results without resorting to nonoptical effects on perception. To examine whether blocking ease influences perception, we conducted several experiments. We examined whether the apparent effects were due to the type of perceptual judgment, the timing of the judgment, and the effectiveness of the paddle. The results are consistent with a perceptual explanation, and help build a case that blocking ease can influence perceived speed. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Performance and ease influence perceived speed

According to the action-specific perception account, perception is a function of optical information and the perceiver's ability to perform the intended action. While most of the evidence for the action-specific perception account is on spatial perception, in the current experiments we examined similar effects in the perception of speed. Tennis players reproduced the time the ball traveled from the feeder machine to when they hit it. The players judged the ball to be moving faster on trials when they hit the ball out-of-bounds than on trials where they successfully hit the ball in-bounds. Follow-up experiments in the laboratory showed that participants judged virtual balls to be moving slower when they played with a bigger paddle in a modified version of Pong. These studies suggest that performance and task ease influence perceived speed.     

Trapped in a tight spot: Scaling effects occur when,according to the action-specific account,they should not,and fail to occur when they should

The action-specific account of perception claims that what we see is perceptually scaled according to our action capacity. However, it has been argued that this account relies on an overly confirmatory research strategy—predicting the presence of, and then finding, an effect (Firestone & Scholl, 2014). A comprehensive approach should also test disconfirmatory predictions, in which no effect is expected. In two experiments, we tested one such prediction based on the action-specific account, namely that scaling effects should occur only when participants intend to act (Witt, Proffitt, & Epstein, 2005). All participants wore asymmetric gloves in which one glove was padded with extra material, so that one hand was wider than the other. Participants visually estimated the width of apertures. The action-specific account predicts that the apertures should be estimated as being narrower for the wider hand, but only when participants intend to act. We found this scaling effect when it should not have occurred (Exp. 1, for participants who did not intend to act), as well as no effect when it should have occurred (Exp. 2, for participants who intended to act but were given a cover story for the visibility and position of their hands). Thus, the cover story used in Experiment 2 eliminated the scaling effect found in Experiment 1. We suggest that the scaling effect observed in Experiment 1 likely resulted from demand characteristics associated with using a salient, unexplained manipulation (e.g., telling people which hand to use to do the task). Our results suggest that the action-specific account lacks predictive power.     

Armed and attentive: Holding a weapon can bias attentional priorities in scene viewing

The action-specific perception hypothesis (Witt, Current Directions in Psychological Science 20: 201–206, 2011) claims that the environment is represented with respect to potential interactions for objects present within said environment. This investigation sought to extend the hypothesis beyond perceptual mechanisms and assess whether action-specific potential could alter attentional allocation. To do so, we examined a well-replicated attention bias in the weapon focus effect (Loftus, Loftus, & Messo, Law and Human Behaviour 1, 55–62, 1987), which represents the tendency for observers to attend more to weapons than to neutral objects. Our key manipulation altered the anticipated action-specific potential of observers by providing them a firearm while they freely viewed scenes with and without weapons present. We replicated the original weapon focus effect using modern eye tracking and confirmed that the increase in time looking at weapons comes at a cost of less time spent looking at faces. Additionally, observers who held firearms while viewing the various scenes showed a general bias to look at faces over objects, but only if the firearm was in a readily usable position (i.e., pointed at the scenes rather than holstered at one’s side). These two effects, weapon focus and the newly found bias to look more at faces when armed, canceled out one another without interacting. This evidence confirms that the action capabilities of the observer alter more than just perceptual mechanisms and that holding a weapon can change attentional priorities. Theoretical and real-world implications are discussed.     

Action potential influences spatial perception: Evidence for genuine top-down effects on perception

The action-specific account of spatial perception asserts that a perceiver’s ability to perform an action, such as hitting a softball or walking up a hill, impacts the visual perception of the target object. Although much evidence is consistent with this claim, the evidence has been challenged as to whether perception is truly impacted, as opposed to the responses themselves. These challenges have recently been organized as six pitfalls that provide a framework with which to evaluate the empirical evidence. Four case studies of action-specific effects are offered as evidence that meets the framework’s high bar, and thus that demonstrates genuine perceptual effects. That action influences spatial perception is evidence that perceptual and action-related processes are intricately and bidirectionally linked.     

Human and machine: Evaluating whether action automation influences visual perception

The action-specific account of perception suggests that our perceptual system is influenced by information about our ability to act in our environment and, thus, affects our perception. However, the specific information about action that is influential for perception is still largely unknown. For example, if a goal is achieved through automation rather than action, is perception influenced because the goal was achieved or is perception immune because the act was automated rather than performed by the observer? In four experiments, we examined whether automating a paddle to block a moving ball in a computer game similar to Pong affects perception of the ball’s speed. Results indicate that the automation used here did not affect speed perception of the target. Whereas tools such as reach-extending sticks and various-sized paddles are both incorporated into one’s body schema and also influence spatial perception, automation, our results imply that automation is not incorporated into one’s body schema and does not affect spatial perception. The dissociation in how the mind treats tools versus automation could have several implications as automation becomes more prevalent in daily life.

     

A perceiver’s own abilities influence perception,even when observing others

Perceptual judgments of objects, such as judgments of their size, distance, and speed, are influenced by the perceiver’s ability to act on these objects. For example, objects that are easier to block appear to be moving slower than objects that are more difficult to block. These effects are known as action-specific effects. Recent research has found similar patterns when a person observes someone else act: When the other person’s task is more difficult, objects look farther away and faster to the observer, whereas when the other person’s task is easier, the objects look closer and slower to the observer. These previous findings that another person’s ability penetrates into perceptual judgments challenge the idea that action-specific effects are specific to the perceiver’s own abilities. However, in the present study, we show that the apparent effects of another person’s ability on the observer’s judgments are actually due to the observer’s own abilities as if he or she was in the other person’s situation. This implicates a type of self-projection motor simulation mechanism. The results also preserve the critical idea that action-specific effects are perceiver specific and, consequently, that they could be adaptive for planning future actions.     

Action-specific effects in perception and their potential applications

Spatial perception is biased by action. Hills appear steeper and distances appear farther to individuals who would have to exert more effort to traverse the space. Objects appear closer, smaller, and faster when they are easier to obtain. Athletes who are playing better than others see their targets as bigger. These phenomena are collectively known as action-specific effects on perception. In this target article, we review evidence for action-specific effects, including evidence that they reflect genuine differences in perception, and speculate on possible applications of action's influence on vision.     

An effect of mood on the perception of geographical slant

Previous research has shown that hills appear steeper to those who are fatigued, encumbered, of low physical fitness, elderly, or in declining health (Bhalla & Proffitt, 1999; Proffitt, Bhalla, Gossweiler, & Midgett, 1995). The prevailing interpretation of this research is that observers’ perceptions of the environment are influenced by their capacity to navigate that environment. The current studies extend this programme by investigating more subtle embodied effects on perception of slant; namely those of mood. In two studies, with two different mood manipulations, and two estimates of slant in each, observers in a sad mood reported hills to be steeper. These results support the role of mood and motivational factors in influencing spatial perception, adding to the previous work showing that energetic potential can influence perception.     

Perception and production of object-related grasping in 6-month-olds

In this study, 6-month-olds’ perception of an object-related human grasping action was compared with their level of grasping performance using a within-participants design. In the action perception task, infants were presented with the video of an actor’s grasping movement toward an occluded target object. Subsequently, an expected and an unexpected final state of this grasping movement were presented simultaneously, and infants’ looking times were measured. In the action production task, infants were presented with three graspable objects. Infants’ grasping behavior was coded to be either palmar or thumb-opposite grasping. Results indicate that infants who were already able to perform a thumb-opposite grasp differentiated between the two final states in the action perception task by looking longer toward the unexpected final state. In contrast, infants who showed only palmar grasps looked equally long toward both final states. This finding supports the assumption that action perception and action control are already closely related in infants as young as 6 months.     

Discovering your inner Gibson: Reconciling action-specific and ecological approaches to perception–action

Both the action-specific perception account and the ecological approach to perception–action emphasize the role of action in perception. However, the action-specific perception account demonstrates that different percepts are possible depending on the perceiver’s ability to act, even when the same optical information is available. These findings challenge one of the fundamental claims of the ecological approach—that perception is direct—by suggesting that perception is mediated by internal processes. Here, we sought to resolve this apparent discrepancy. We contend that perception is based on the controlled detection of the information available in a global array that includes higher-order patterns defined across interoceptive and exteroceptive stimulus arrays. These higher-order patterns specify the environment in relation to the perceiver, so direct sensitivity to them would be consistent with the ecological claims that perception of the environment is direct and animal-specific. In addition, the action-specific approach provides further evidence for the theory of affordances, by demonstrating that even seemingly abstract properties of the environment, such as distance and size, are ultimately perceived in terms of an agent’s action capabilities.     

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.     

Young Children's Self-Generated Object Views and Object Recognition

Two important and related developments in children between 18 and 24 months of age are the rapid expansion of object name vocabularies and the emergence of an ability to recognize objects from sparse representations of their geometric shapes. In the same period, children also begin to show a preference for planar views (i.e., views of objects held perpendicular to the line of sight) of objects they manually explore. Are children's emerging view preferences somehow related to contemporary changes in object name vocabulary and object perception? Children aged 18 to 24 months old explored richly detailed toy objects while wearing a head camera that recorded their object views. Both children's vocabulary size and their success in recognizing sparse three-dimensional representations of the geometric shapes of objects were significantly related to their spontaneous choice of planar views of those objects during exploration. The results suggest important interdependencies among developmental changes in perception, action, word learning, and categorization in very young children.     

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.

     

Impact of action planning on spatial perception: Attention matters

Previous research suggested that perception of spatial location is biased towards spatial goals of planned hand movements. In the present study I show that an analogous perceptual distortion can be observed if attention is paid to a spatial location in the absence of planning a hand movement. Participants judged the position of a target during preparation of a mouse movement, the end point of which could deviate from the target by a varying degree in Exp. 1. Judgments of target position were systematically affected by movement characteristics consistent with perceptual assimilation between the target and the planned movement goal. This effect was neither due to an impact of motor execution on judgments (Exp. 2) nor due to characteristics of the movement cues or of certain target positions (Exp. 3, Exp. 5A). When the task included deployment of attention to spatial positions (former movement goals) in preparation for a secondary perceptual task, an effect emerged that was comparable with the bias associated with movement planning (Exp. 4, Exp. 5B). These results indicate that visual distortions accompanying manipulations of variables related to action could be mediated by attentional mechanisms.     

Mouthing and Grasping of Objects by Young Infants

Mouthing and grasping objects are two common behaviors observed in young infants, although little is known about the relations between these activities. Data from two previously published experiments on 4- to 8-month-old infants (N = 133) are further analyzed to investigate if: (a) variation in object size and shape influences whether objects are mouthed after being picked up, and (b) infants modify their grip configurations in order to mouth objects as opposed to performing other prehensile actions. The results showed that larger objects increased the propensity of young infants to mouth objects; object size also contributed to differentiating the grip configuration according to the intent of the action. The findings suggest that infants as young as 4 months perceive that object properties afford different actions and differentiate grip configurations to realize specific task goals.