Language-induced modulation during the prediction of others' actions

Processing of action words has been shown to influence the perception of the actions the words refer to. Specifically, the accuracy with which people predict the future course of actions observed in another individual seems to be affected by verbal primes. Two processes may be involved in action prediction; dynamic simulation (updating) and static matching. The present study examined this issue by testing the impact of action verb processing on action prediction performance using a masked priming paradigm. Evidence of dynamic updating was revealed after prime verbs expressing dynamic actions (e.g., 'to catch') but not those expressing static actions (e.g., 'to lean'). In contrast to previous work, the primes were masked and did not require any response at all. Hence, our results indicate that implicit action-related linguistic processing may trigger action simulation that in turn might affect action prediction (see also Liepelt, Dolk, & Prinz, Psychological Research, 2012, in this issue).     

Movement kinematics affect action prediction: comparing human to non-human point-light actions

The influence of movement kinematics on the accuracy of predicting the time course of another individual's actions was studied. A human point-light shape was animated with human movement (natural condition) and with artificial movement that was more uniform regarding velocity profiles and trajectories (artificial condition). During brief occlusions, the participants predicted the actions in order to judge after occlusion whether the actions were continued coherently in time or shifted to an earlier or later frame. Error rates and reaction times were increased in the artificial compared to the natural condition. The findings suggest a perceptual advantage for movement with a human velocity profile, corresponding to the notion of a close interaction between observed and executed movement. The results are discussed in the framework of the simulation account and alternative interpretations are provided on the basis of correlations between the velocity profiles of natural and artificial movements with prediction performance.     

The relative influences of movement kinematics and extrinsic object characteristics on the perception of lifted weight

Humans are able to perceive unique types of biological motion presented as point-light displays (PLDs). Thirty years ago, Runeson and Frykholm (Human Perception and Performance, 7(4), 733, 1981, Journal of Experimental Psychology: General, 112(4), 585, 1983) studied observers’ perceptions of weights lifted by actors and identified that the kinematic information in a PLD is sufficient for an observer to form an accurate perception of the object weight. However, research has also shown that extrinsic object size characteristics also influence the perception of object weight (Gordon, Forssberg, Johansson, & Westling in Experimental Brain Research, 83(3), 477–482, 1991). This study addresses the relative contributions of these two types of visual information to observers’ perceptions of lifted weight, through an experiment in which participants viewed an actor lifting boxes of various sizes (small, medium, or large) and weights (25, 50, or 75 lb) under four PLD conditions—box-at-rest, moving-box, actor-only, and actor-and-box—and one full-vision video condition, and then provided a weight estimate for each box lifted. The results indicated that lift kinematics and box size contributed independently to weight perception. Interestingly, the most robust weight differentiations were elicited in the conditions in which both types of information were presented concurrently, despite their converse natures. Furthermore, full-vision video presentation, which contained visual information beyond kinematics and object information, elicited the best estimates.     

On the relations between action planning, object identification, and motor representations of observed actions and objects

Recent evidence suggests that viewing a static prime object (a hand grasp), can activate action representations that affect the subsequent identification of graspable target objects. The present study explored whether stronger effects on target object identification would occur when the prime object (a hand grasp) was made more action-rich and dynamic. Of additional interest was whether this type of action prime would affect the generation of motor activity normally elicited by the target object. Three experiments demonstrated that grasp observation improved the identification of grasp-congruent target objects relative to grasp-incongruent target objects. We argue from this data that identifying a graspable object includes the processing of its action-related attributes. In addition, grasp observation was shown to influence the motor activity elicited by the target object, demonstrating interplay between action-based and object-based motor coding.     

Representing others' actions: the role of expertise in the aging mind

A large body of evidence suggests that action execution and action observation share a common representational domain. To date, little is known about age-related changes in these action representations that are assumed to support various abilities such as the prediction of observed actions. The purpose of the present study was to investigate (a) how age affects the ability to predict the time course of observed actions; and (b) whether and to what extent sensorimotor expertise attenuates age-related declines in prediction performance. In a first experiment, older adults predicted the time course of familiar everyday actions less precisely than younger adults. In a second experiment, younger and older figure skating experts as well as age-matched novices were asked to predict the time course of figure skating elements and simple movement exercises. Both young age and sensorimotor expertise had a positive influence on prediction performance of figure skating elements. The expertise-related benefit did not show a transfer to movement exercises. Together, the results suggest a specific decline of action representations in the aging mind. However, extensive sensorimotor experience seems to enable experts to represent actions from their domain of expertise more precisely even in older age.     

Coupling kinematics of memory and kinematics of movement: the conditions for a psychological relativity

The organization of spatial and temporal information relative to memory-movement interactions was studied in a recall task. Stimuli consisted of four different configurations of eight dots, presented sequentially. In two configurations, the stimuli were spatiotemporal congruent, with (constant or variable) inter-stimulus distances corresponding to (constant or variable) inter-stimulus time intervals. In the other two configurations, the stimuli were spatiotemporal incongruent, with (constant or variable) inter-stimulus distances not corresponding to (variable or constant) inter-stimulus time intervals. After a learning phase consisting of 20 presentations of the target configuration, participants performed a series of pointing movements to reproduce both spatial and temporal characteristics of the stimulus 60 times in succession without ever re-examining the target configuration. Classically, in incongruent spatiotemporal conditions, the reproduction of, respectively, constant distances or constant time intervals are strongly disturbed by the simultaneous perception of variable inter-stimulus time intervals (Tau effect) or variable distances (Kappa effect). We assume that these spatiotemporal dependencies, which occur when the response relates to one dimension only, crucially depend on the non-integration of motoric aspects in memory.     

Action observation modulates auditory perception of the consequence of others' actions

We can easily discriminate self-produced from externally generated sensory signals. Recent studies suggest that the prediction of the sensory consequences of one’s own actions made by forward model can be used to attenuate the sensory effects of self-produced movements, thereby enabling a differentiation of the self-produced sensation from the externally generated one. The present study showed that attenuation of sensation occurred both when participants themselves performed a goal-directed action and when they observed experimenter performing the same action, although they clearly reported that the tones were produced by other during action observation and by themselves during their own action. These results suggest that sensory prediction of action modulates ongoing auditory processing irrespective of who produces the sounds and that the explicit judgment of agency does not necessarily rely on the same mechanisms on which implicit perceptual measures such as sensory attenuation rely.     

Cognition, action, and object manipulation

Although psychology is the science of mental life and behavior, little attention has been paid to the means by which mental life is translated into behavior. One domain in which links between cognition and action have been explored is the manipulation of objects. This article reviews psychological research on this topic, with special emphasis on the tendency to grasp objects differently depending on what one plans to do with the objects. Such differential grasping has been demonstrated in a wide range of object manipulation tasks, including grasping an object in a way that reveals anticipation of the object's future orientation, height, and required placement precision. Differential grasping has also been demonstrated in a wide range of behaviors, including 1-hand grasps, 2-hand grasps, walking, and transferring objects from place to place as well as from person to person. The populations in which the tendency has been shown are also diverse, including nonhuman primates as well as human adults, children, and babies. The tendency is compromised in a variety of clinical populations and in children of a surprisingly advanced age. Verbal working memory is compromised as well if words are memorized while object manipulation tasks are performed; the recency portion of the serial position curve is reduced in this circumstance. In general, the research reviewed here points to rich connections between cognition and action as revealed through the study of object manipulation. Other implications concern affordances, Donders' law, naturalistic observation, and the teaching of psychology. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

The kinematics,movement phasing and timing of a skilled action in response to varying conditions of uncertainty

This study was designed to provide a detailed analysis of the parameters which interact to produce a field hockey drive. The drive was performed by an elite performer under two conditions of uncertainty (Blocked and Random). The subject was asked to drive a field hockey ball toward a specified target. In the Blocked condition the speed of the approaching ball remained constant (20, 30 and 40 m.p.h.) while in the Random condition these speeds were randomly assigned to each trial. Cine analysis of the subject's successful responses under the two experimental conditions led to an investigation of the kinematics, phasing, and timing of the stroke. The subject placed emphasis upon varying the initial phases of the stroke (i.e., backswing and preparatory phases) in order to produce a temporally consistent ballistic downswing to ball contact. It seemed likely that the subject appraised the ball speed that was being delivered and then incorporated additional stick movement to ‘mark time’ before initiating temporally consistent movement phases, as spatial uncertainty increased, the subject delayed her response initiation, but then tended to respond in intervals of one reaction time for each stroke phase. Consistency was evident for displacement and initiation point values, but to a lesser extent than existed for the other variables. However, as a result of this adjustment in spatial location and displacement of the stick end during the preliminary phases of the response, the subject was able to produce a consistent and accurate ballistic downswing.     

Predicting others' actions via grasp and gaze: evidence for distinct brain networks

During social interactions, how do we predict what other people are going to do next? One view is that we use our own motor experience to simulate and predict other people's actions. For example, when we see Sally look at a coffee cup or grasp a hammer, our own motor system provides a signal that anticipates her next action. Previous research has typically examined such gaze and grasp-based simulation processes separately, and it is not known whether similar cognitive and brain systems underpin the perception of object-directed gaze and grasp. Here we use functional magnetic resonance imaging to examine to what extent gaze- and grasp-perception rely on common or distinct brain networks. Using a 'peeping window' protocol, we controlled what an observed actor could see and grasp. The actor could peep through one window to see if an object was present and reach through a different window to grasp the object. However, the actor could not peep and grasp at the same time. We compared gaze and grasp conditions where an object was present with matched conditions where the object was absent. When participants observed another person gaze at an object, left anterior inferior parietal lobule (aIPL) and parietal operculum showed a greater response than when the object was absent. In contrast, when participants observed the actor grasp an object, premotor, posterior parietal, fusiform and middle occipital brain regions showed a greater response than when the object was absent. These results point towards a division in the neural substrates for different types of motor simulation. We suggest that left aIPL and parietal operculum are involved in a predictive process that signals a future hand interaction with an object based on another person's eye gaze, whereas a broader set of brain areas, including parts of the action observation network, are engaged during observation of an ongoing object-directed hand action.     

Vicarious moral licensing: the influence of others' past moral actions on moral behavior

This article investigates the effect of others' prior nonprejudiced behavior on an individual's subsequent behavior. Five studies supported the hypothesis that people are more willing to express prejudiced attitudes when their group members' past behavior has established nonprejudiced credentials. Study 1a showed that participants who were told that their group was more moral than similar other groups were more willing to describe a job as better suited for Whites than for African Americans. In Study 1b, when given information on group members' prior nondiscriminatory behavior (selecting a Hispanic applicant in a prior task), participants subsequently gave more discriminatory ratings to the Hispanic applicant for a position stereotypically suited for majority members (Whites). In Study 2, moral self-concept mediated the effect of others' prior nonprejudiced actions on a participant's subsequent prejudiced behavior such that others' past nonprejudiced actions enhanced the participant's moral self-concept, and this inflated moral self-concept subsequently drove the participant's prejudiced ratings of a Hispanic applicant. In Study 3, the moderating role of identification with the credentialing group was tested. Results showed that participants expressed more prejudiced attitudes toward a Hispanic applicant when they highly identified with the group members behaving in nonprejudiced manner. In Study 4, the credentialing task was dissociated from the participants' own judgmental task, and, in addition, identification with the credentialing group was manipulated rather than measured. Consistent with prior studies, the results showed that participants who first had the opportunity to view an in-group member's nonprejudiced hiring decision were more likely to reject an African American man for a job stereotypically suited for majority members. These studies suggest a vicarious moral licensing effect.     

The role of movement and object in action memory: a comparative study between blind, blindfolded and sighted subjects

Two experiments systematically compared four SPT conditions involving real/imaginary movement and real/imaginary object with one VT condition involving no enactment and no object. To test the effect of visual information on SPT memory, sighted subjects were compared with blindfolded subjects (in Experiment 1) and blind subjects (in Experiment 2). All subjects learned all SPTs and VTs. Free recall data showed no difference between the SPT conditions and between the groups of subjects; only blind subjects were found to be limited in the use of visualization strategy. All SPTs were recalled better than VTs, indicating that the enactment effect is not determined by either movement or object alone, rather both have an effective role and are equally involved for obtaining the enactment effect. The results provide no support for the motor encoding and multimodality views of SPTs, but are in line with the episodic integration view which assumes that neither movement nor object are of special importance, rather both have contribution in the enactment effect.     

Boundary extension: the role of magnification, object size, context, and binocular information

Boundary extension is a tendency to remember close-up scenes as if they extended beyond the occluding boundaries. The authors explored the contributing factors using brief retention intervals and computer-generated images. Boundary extension turns out to be more complex than previously thought and is not linked to the effects of image magnification and field-of-view changes. Although this is consistent with the idea that boundary extension is the product of the activation of a mental schema that provides information of what is likely to exist outside the picture boundaries, the authors also found that properties of the object at the center of the picture can affect boundary extension independently of the information at the boundaries. In a test of boundary extension using stereograms, the effect does not seem to depend on amount of perceived depth, suggesting a weaker link to perception of space than previously hypothesized.     

The relative contribution of scene context and target features to visual search in scenes

Many experiments have shown that knowing a targets visual features improves search performance over knowing the target name. Other experiments have shown that scene context can facilitate object search in natural scenes. In this study, we investigated how scene context and target features affect search performance. We examined two possible sources of information from scene context—the scenes gist and the visual details of the scene—and how they potentially interact with target-feature information. Prior to commencing search, participants were shown a scene and a target cue depicting either a picture or the category name (or no-information control). Using eye movement measures, we investigated how the target features and scene context influenced two components of search: early attentional guidance processes and later verification processes involved in the identification of the target. We found that both scene context and target features improved guidance, but that target features also improved speed of target recognition. Furthermore, we found that a scenes visual details played an important role in improving guidance, much more so than did the scenes gist alone.     

Experience, context, and the visual perception of human movement

Why are human observers particularly sensitive to human movement? Seven experiments examined the roles of visual experience and motor processes in human movement perception by comparing visual sensitivities to point-light displays of familiar, unusual, and impossible gaits across gait-speed and identity discrimination tasks. In both tasks, visual sensitivity to physically possible gaits was superior to visual sensitivity to physically impossible gaits, supporting perception-action coupling theories of human movement perception. Visual experience influenced walker-identity perception but not gait-speed discrimination. Thus, both motor experience and visual experience define visual sensitivity to human movement. An ecological perspective can be used to define the conditions necessary for experience-dependent sensitivity to human movement.     

Self-monitoring and the prediction of one's own and others' personality test scores

This study had two aims. Firstly, it examined the similarity between subjects' ratings of themselves and others and their scores on various personality tests. A group of 264 undergraduates in psychology completed Snyder's (1974) Self-Monitoring Scale and the Neuroticism and Extraversion Scales from the Eysenck Personality Questionnaire (Eysenck and Eysenck, 1975; 1986). Then, they estimated both their own score and that of a peer on those questionnaires. The results showed that subjects (i) were fairly good at estimating their own and others' extraversion and neuroticism scores, (ii) were less accurate at estimating self-monitoring scores, (iii) were better at predicting their own scores than those of others, and (iv) erroneously believed themselves to be significantly similar to the chosen peer. Secondly, individual differences in the accuracy of personality estimation were studied. According to Synder's (1974) self-monitoring construct, people high in self-monitoring would be especially adept at reading others' expressive behaviours; therefore, any differences in the accuracy of perceiving the personality of others might be associated with differences in self-monitoring. High self-monitors were more accurate than low self-monitors at estimating neuroticism scores for others. Another implication of the self-monitoring theory is that, taking high and low self-monitors as targets of others' estimations, there should be greater discrepancy between actual scores and peer estimations for high self-monitors. The results here supported this prediction, but only in self-monitoring estimation.     

The egocentric bias: Seeing oneself as cause and target of others' behavior

The egocentric bias—the tendency to see oneself as both cause and target of another person's behavior—was examined in the context of a small group interaction. Pairs of subjects plus a confederate conducted a short discussion, their goal being to achieve consensus on a specific topic. The discussion was interrupted by the experimenter when the confederate summarized his/her opinion. It was found that subjects were more likely to see themselves as a cause as well as a target of the confederate's last statement compared to the way they were seen by other group members. Subjects were also more likely to exaggerate the amount of attention they received from the confederate. The overall egocentric bias scores were correlated with subjects' level of self-esteem. Cognitive and motivational processes that may account for this bias were discussed.     

Anxiety, movement kinematics, and visual attention in elite-level performers

We tested the predictions of Attentional Control Theory (ACT) by examining the effect of anxiety on attention control and the subsequent influence on both performance effectiveness and performance efficiency within a perceptual-motor context. A sample (N = 16) of elite shotgun shooters was tested under counterbalanced low (practice) and high (competition) anxiety conditions. A head-mounted, corneal reflection system allowed point of gaze to be calculated in relation to the scene, while motion of the gun was evaluated using markers placed on the barrel which were captured by two stationary cameras and analyzed using optical tracking software. The quiet eye (QE) duration and onset were analyzed along with gun barrel displacement and variability; performance outcome scores (successful vs. unsuccessful) were also recorded. QE (Vickers, 1996) is defined as the final fixation or tracking gaze that is located on a specific location/object in the visual display for a minimum of 100 ms. Longer QE durations have been linked to successful performance in previous research involving aiming tasks. Participants demonstrated shorter quiet eye durations, and less efficient gun motion, along with a decreased performance outcome (fewer successful trials) under high compared with low anxiety conditions. The data support the predictions of ACT with anxiety disrupting control processes such that goal-directed attention was compromised, leading to a significant impairment in performance effectiveness.