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Human movement trajectories can reveal useful insights regarding the underlying mechanisms of human behaviors. Extracting information from movement trajectories, however, could be challenging because of their complex and dynamic nature. The current paper presents a Python toolkit developed to help users analyze and extract useful information from the trajectories of discrete rapid aiming movements executed by humans. This toolkit utilizes various open-source Python libraries, such as NumPy and SciPy, and offers a collection of commonly used functions to analyze movement trajectory data. To ensure flexibility and ease of use, this toolkit offers two approaches: an automated approach that processes raw data and generates relevant measures automatically, and a manual approach that allows users to selectively use different functions based on their specific needs. A behavioral experiment based on the spatial cueing paradigm was conducted to illustrate how one can use this toolkit in practice. Readers are encouraged to access the publically available data and relevant analysis scripts as an opportunity to learn about kinematic analysis for human movements.

The type of clothing worn, revealing versus concealing, can affect the performance of women on cognitive tasks. This difference in performance may arise because of changes in body awareness that may draw cognitive resources from the goal task. The present study investigated the influence of the style of athletic clothing and body awareness on visual-motor performance in women. Participants (women ages 18-35 years) were randomly assigned to wear tight and revealing (TR group, n = 40) or loose and concealing (LC group, n = 40) athletic clothing. All participants completed the same visual-motor aiming task to assess spatiotemporal measures of motor performance. In addition to the clothing, participants were primed to be conscious of their bodies via measurements of height, weight, and waist circumference; photographs taken of their bodies; a computerized body-size distortion task; and a mirror in the testing chamber. Results revealed that the TR group had increased movement time variability and did not show performance improvements relative to the LC group. These differences suggest that style of clothing may influence motor performance in women by reallocating cognitive resources towards the body and away from the motor task at hand. This research highlights the interactions between cognitive and motor processes and, potentially, the importance of considering the impact of clothing on performance in many different contexts.

Gaze direction and emotion expression are salient facial features that facilitate social interactions. Previous studies addressed how gaze direction influences the evaluation and recognition of emotion expressions, but few have tested how emotion expression influences attentional processing of direct versus averted gaze faces. The present study examined whether the prioritization of direct gaze (toward the observer) relative to averted gaze (away from the observer) is modulated by the emotional expression of the observed face. Participants identified targets presented on the forehead of one of four faces in a 2 × 2 design (gaze direction: direct/averted; motion: sudden/static). Emotion expressions of the faces (neutral, angry, fearful, happy, disgusted) differed across participants. Direct gaze effects emerged-response times were shorter for targets on direct gaze than on averted gaze faces. This direct gaze effect was enhanced in angry faces (approach-oriented) and reduced in fearful faces (avoidance-oriented). "Weaker" approach- and avoidance-oriented expressions (happy and disgusted) did not modulate the direct gaze effect. These findings suggest that the context of facial emotion expressions influences attentional processing. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Humans not only perform a variety of actions, but they also simulate or imagine themselves performing those actions. When individuals physically execute goal-directed hand movements, eye movements typically precede the hand movements to the target to enhance movement accuracy. Studies have also revealed that eye movements emerge during motor imagery. Although eye-hand coordination is clearly important for the execution of a goal-directed movement, less is known about the role or expression of eye movements in an imagined movement. The present experiments were designed to investigate the role of eye movements during an executed and imagined reciprocal aiming task. Participants executed and imagined reciprocal aiming movements under conditions in which they were allowed to freely move their eyes or were told to fixate at a fixation point. Speed-accuracy trade-offs consistent with Fitts' Law were observed across all conditions suggesting that eye movements were not necessary to execute or imagine movements. Movement times were longest, however, in the imagination task when the eye movements were restricted to the central fixation point, suggesting that eye movements might assist with the accuracy or calibration of the imagination process. Analysis of eye movements during the no fixation imagination task revealed that the eye movements during imagination mimicked the executed hand movements when gaze was not restricted. Overall, these results suggest that although the ability to make eye movements was not necessary for action execution or motor imagery, the use of eye movements likely enhancing the accuracy of motor imagery for this task.

Social cues, such as eye gaze and pointing fingers, can increase the prioritization of specific locations for cognitive processing. A previous study using a manual reaching task showed that, although both gaze and pointing cues altered target prioritization (indexed via reaction times [RTs]), only pointing cues affected action execution (indexed via trajectory deviations). This discrepancy in the effects of gaze and pointing cues on action execution could be because the gaze cue was conveyed through a disembodied head; hence, the model lacked the potential for a body part (i.e., hands) to interact with the target. In the present study, the image of a male gaze model, whose gaze direction coincided with two potential target locations, was centrally presented. The model either had his arms and hands extended underneath the potential target locations, indicating the potential to act on the targets (Experiment 1) or had his arms crossed in front of his chest, indicating a lack of potential to act (Experiment 2). Participants reached to a target that followed a nonpredictive gaze cue at one of three stimulus onset asynchronies (SOA; 100, 350, or 850ms). RTs and reach trajectories of the movements to cued and uncued targets were analyzed. RTs showed a facilitation effect for both Experiments 1 and 2, whereas trajectory analysis revealed facilitatory and inhibitory effects, depending on the SOA, but only in Experiment 1. Results of this study confirmed that when the gaze model has the potential to interact with the cued target location, the model’s gaze would not only affect target prioritization, but also movement execution.

Brief windows of vision presented during reaching movements contribute to endpoint error estimates. It is not clear whether such error detection processes depend on other sources of information (e.g., proprioception and efference). In the current study, participants were presented with a brief window of vision and then judged whether their movement endpoint under- or over-shot the target after: 1) performing an active reach; 2) being passively guided by a robotic arm; and 3) observing a fake hand moved by the robot arm. Participants were most accurate at estimating their endpoint error in the active movement conditions and least accurate in the action observation condition. Thus, both efferent and proprioceptive information significantly contribute to endpoint error detection processes even with brief visual feedback.

Humans operate in complex environments where social interactions require individuals to constantly attend to people and objects around them. Despite the complexity of these interactions from a visuomotor perspective, humans can engage and thrive in social settings. The purpose of the current study was to examine the simultaneous influence of multiple social cues (i.e., ownership and the presence of a coactor) on the processing of objects. Participants performed an object-based compatibility task in the presence and absence of a coacting confederate. Participants indicated whether pictures of mugs (that were either self-owned or unowned) were upright or inverted. The pictures appeared at one of 2 locations (a near or far location relative to the participant) on a computer screen laid flat on (parallel to) the tabletop. When present, the coactor stood on the opposite side of the screen/table. Analysis of response times (RTs) indicated that the processing of objects was influenced by the object's ownership status, the presence of the coactor, and where the object was located on the screen. Specifically, RTs for pictures of self-owned mugs were shorter than unowned mugs, but only when the pictures were located at the near location. Further, the presence of a confederate resulted in shorter RTs for pictures located at the near but not the far location. These findings suggest that when objects were placed at the far location, the additional social cues of ownership and social context did not influence visuomotor processing of the objects. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Movement imagery (MI) is a cognitive process wherein an individual simulates themselves performing a movement in the absence of physical movement. The current paper reports an examination of the relationship between behavioural indexes of MI ability and the magnitude of corticospinal adaptation following MI training. Behavioural indexes of MI ability included data from a questionnaire (MIQ-3), a mental chronometry task, and a hand laterality judgment task. For the measure of corticospinal adaptation, single-pulse transcranial magnetic stimulation (TMS) was administered to elicit thumb movements to determine the representation of thumb movements before and after MI training. MI training involved participants imagining themselves moving their thumb in the opposite direction to the dominant direction of the TMS-evoked movements prior to training. Pre/post-training changes in the direction and velocity of TMS-evoked thumb movements indicated the magnitude of adaptation following MI training. The two main findings were: 1) a positive relationship was found between the MIQ-3 and the pre/post-training changes in the direction of TMS-evoked thumb movements; and 2) a negative relationship between the mental chronometry measure and both measures of corticospinal adaptation following MI training. These results indicate that both ease of imagery and timing of imagery could predict the magnitude of neuroplastic adaptation following MI training. Thus, both these measures may be considered when assessing imagery ability and determining who might benefit from MI interventions.

Multi-modal technologies, including augmented reality (AR) and virtual reality (VR), have become increasingly common in education and training contexts. Despite growing adoption of these technologies, our understanding of how basic perceptual-cognitive processes are influenced or altered by AR and VR mediation remains limited. The present paper describes a pilot study in which participants performed goal-directed reaching movements toward visual illusions in three different mediation conditions: unmediated reality (UR), AR, and VR. This pilot assessed whether the speed-accuracy relationship of reaching movements in different mediation conditions was modulated by contextual information surrounding a target. Preliminary results showed that there was a trend toward an effect of the contextual information in VR, but not in UR or AR. These findings may indicate that movements in VR are generated by different sensorimotor processes than in UR and AR.

The purpose of this study was to explore body image correlates of voluntary consumption of physique-salient media. A secondary aim was to assess changes in affect following media consumption. Young adult men (n = 47, mean age = 20.2 years) and women (n = 87, mean age = 19.5 years) were discretely exposed to images of same-sex models with idealized- and average-physiques while completing an irrelevant computer task. Voluntary gaze at the images was covertly recorded via hidden cameras. Participants also completed measures of affect before and after the computer task. Measures of body-related envy, body appreciation, and self-perceptions of attractiveness, thinness, and physical strength were completed. Men and women did not differ in how often nor for how long they looked at the images overall, but body image variables were differentially associated with their voluntary gaze behaviors. For men, higher body-related envy and lower body appreciation were correlated with more looks at the average-physique model. Although women reported higher body-related envy than men, envy and body appreciation were not significant correlates of gaze behaviors for women. Both men and women experienced a general affective decrease over time, but only for men was the change in negative affect associated with their time spent looking at the ideal-physique image. Overall, these findings suggest that body-related envy and body appreciation influence how men choose to consume physique-salient media, and that media consumption may have negative consequences for post-exposure affect. Body image factors appear to be more strongly associated with behavior in men, perhaps because men are generally less often exposed to physique-salient media and, in particular, to average-physique images.

Spatial skills allow us to mentally imagine and manipulate objects and their spatial relations. These skills are crucial in both every day and expert tasks. The present paper reports on an evaluation of a 3D game developed to train a specific spatial skill known as penetrative thinking—the ability to imagine cross-sections of 3D objects from their surface features. In the game, users change the location and orientation of a virtual plane to make cuts through 3D objects in a series of spatial puzzles. Users operate an interface to position the virtual plane until a “slice” at the location of the plane matches a target cross-section of a virtual object. Multiple spatial puzzles with different properties are completed throughout the game. In one version of the game, users completed the puzzles in an immersive virtual environment and operated a tangible interface to move the virtual plane. A secondary version of the game required users to view the puzzles in a virtual environment displayed on a computer screen, and to position the slicing plane with a keyboard and mouse. Participants (n= 45) completed a measure of penetrative thinking (Santa Barbara Solids Test) before and after completing one of three interventions: the game with the tangible interface (n= 15), the game with the keyboard interface (n= 15), or a series of (control) questions (n= 15). Although there were no significant pre-/post-intervention changes in penetrative thinking in any of the groups, participants' performance in the game correlated with scores on a standardized test of penetrative thinking. These results provide evidence that the game and the standardized test accessed similar spatial skills and, as a consequence, indicate that the 3D game has the potential to be a valid approach for training penetrative thinking skills.

When presented with two different target–penalty configurations of similar maximum expected gain (MEG), participants prefer aiming to configurations with more advantageous spatial, rather than more advantageous gain parameters—perhaps due to the motor system’s inherent prioritisation of spatial information during movements with high accuracy demands such as aiming. To test this hypothesis, participants in the present studies chose between target–penalty configurations via key presses to reduce the importance of spatial parameters of the response and performance-related feedback. Configurations varied in spatial (target–penalty region overlap) and gain parameters (negative penalty values) and could have similar or different MEG. Choices were made without prior aiming experience (Experiment 1), after aiming experience provided information of movement variability (Experiment 2), or after aiming experience provided information of movement variability and outcome feedback (Experiment 3). Overall, configurations with advantageous spatial or gain parameters were chosen equally (Both-Similar condition) in all experiments. However, average behaviour at the group level was not reflective of the behaviour of most individual participants with three subgroups emerging: those with a value preference, distance preference, or no preference. In Experiments 1 and 2, these individual differences cannot be explained by MEG differences between configurations or participants’ movement variability, but these variables predicted choice behaviour in Experiment 3. Further in the Both-Different condition, participants only selected the larger MEG configuration at a level above chance when both variability and outcome information were given prior to the key press task (Experiment 3). In sum, the data indicate that prioritisation of spatial information did not emerge at the group level when performing key presses and more optimal behaviour emerged when information regarding movement variability and outcome feedback were given.

Attentional Control Theory states that anxiety can cause attention to be allocated to irrelevant sources of information by hindering the ability to control attention and focus on the information that matters. In a separate line of inquiry, action-centred views of attention state that non-target distractors involuntarily activate response codes that may cause interference with target-directed movements (distractor interference effect). Due to the proposed negative effects of anxiety on attentional control, we examined whether anxiety could also modulate distractor interference. Participants executed target-directed aiming movements to one of three targets with the potential of a distractor being presented at near or far locations. Distractors were presented at different times with respect to the target presentation in order to explore the excitatory (0, −100 ms) and inhibitory (−850 ms) processing of the distractor. As a broad indication of the effect of anxiety, the analysis of no distractor trials indicated a lower proportion of time and displacement to reach peak velocity under high compared to low anxiety conditions. Meanwhile, the typical excitatory influence of the distractors located near, compared to far, at a short distractor-onset asynchrony was found in movement time and overall response time. However, this distractor excitation was even greater under high compared to low anxiety in the reaction time component of the response. These findings broadly implicate the attentional control perspective, but they further indicate an influence of anxiety on the excitation rather than inhibition of responses.

Many researchers have proposed that when an individual observes the actions of another individual, the observer simulates the action using many of the same neural areas that are involved in action production. The present study was designed to test this simulation hypothesis by comparing the perception of multisensory stimuli during both the execution and observation of an aiming action. The present work used the fusion illusion - an audio-visual illusion in which two visual stimuli presented with one auditory stimulus are erroneously perceived as being one visual stimulus. Previous research has shown that, during action execution, susceptibly to this illusion is reduced early in the execution of the movement when visual information may be more highly weighted than other sensory information. We sought to determine whether or not a non-acting observer of an action showed a similar reduction in susceptibility to the fusion illusion. Participants fixated a target and either executed or observed a manual aiming movement to that target. Audiovisual stimuli were presented at 0, 100, or 200 ms relative to movement onset and participants reported the number of perceived flashes after the movement was completed. Analysis of perceived flashes revealed that participants were less susceptible to the fusion illusion when the stimuli were presented early (100 ms) relative to later in the movement (200 ms). Critically, this pattern emerged in both execution and observation tasks. These findings support the hypothesis that observers simulate the performance of the actor and experience comparable real-time alterations in multisensory processing.

Manual handling training may be improved if it relied on the provision of individualized, augmented feedback about key movement features. The purpose of this study was to compare the reduction in sagittal spine motion during manual lifting tasks following two training approaches: didactic (DID) and augmented feedback (AUG). Untrained participants (n = 26) completed lifting tests (box, medication bag, and paramedic backboard) and a randomly-assigned intervention involving 50 practice box lifts. Lifting tests were performed immediately before and after training, and one-week after interventions. Both groups exhibited reductions in spine motions immediately and one-week after the interventions. However, the AUG intervention group elicited significantly greater reductions in 5 of 12 between-group comparisons (3 tasks × 4 spine motion variables). The results of the current study support the use of augmented feedback-based approaches to manual handling training over education-based approaches.

The purpose of the present study was to assess the degree to which children and adolescents represent and match the observed body parts of others onto the internal representation of their own body parts. Male and female participants of different age groups (7–9, 10–12, and 13–16 years old) completed a body-part compatibility task in which they responded to coloured targets (relevant feature) presented over the hand or foot (irrelevant feature) of pictures of male models of different ages (7, 11, and 15 years old). Body-part compatibility effects emerged for the males in the 10–12 and 13–16-year-old age groups, which only occurred when viewing models of their own age-group peers (i.e., 11 and 15 year old models, respectively). In contrast, no body-part compatibility effects were found for males in the 7–9-year-old group nor in any of the three groups of females. Based on these data, it is suggested that children and adolescent males seem to develop the ability to match the bodies of other males to their own after 9 years of age and this matching process seems strongest for their age-matched peers.

Objectives Test the relationships between implicit gender stereotypes and perceptions of resistance training pleasantness, resistance training motivation, and participation among men and women. Test whether gender role moderates the effect of stereotypes on resistance training participation in men and women. Design Implicit associations between resistance training and masculinity and pleasantness were measured using an Affect Misattribution Procedure (AMP). Moderated mediation analyses were conducted to test motivation as a mediator of the relationship between implicit associations and behavior. Method Participants (n = 170; 46% male) completed an AMP and measures of motivation for and participation in resistance training. Results Women's implicit associations between exercise and masculinity were not associated with their motivation for or participation in resistance training. The strength of men's implicit masculinity-resistance training association was negatively related to minutes of resistance training per week, mediated by lower autonomous motivation, 95%CI [−419.15 to −11.10]. The association between implicit resistance training pleasantness and behavior was mediated by autonomous motivation in women, 95%CI [2.54 to 313.55], with similar trends in men 95%CImen [−3.00 to 320.38]. Conclusion Based on these findings, implicit associations with masculinity are not associated with women's participation in exercise. However, implicitly endorsing gender-stereotypes for resistance training is associated with lower participation rates in men.

Motor imagery (MI) is a cognitive motor process wherein a person consciously imagines themselves performing a movement. Previous transcranial magnetic stimulation (TMS) studies have demonstrated that physical and observational training can elicit neuroplastic adaptations in the cortical representation of movement. It has been shown that these cortical adaptations can also occur following MI training. These changes are thought to occur because of a training-dependent potentiation (i.e. increased excitability) of the trained movement representation. To test this hypothesis, the current experiment assessed the relationship between motor cortex excitability during MI and the magnitude of motor cortical adaptations following MI training. Prior to training, single-pulse TMS was used to determine the dominant direction of TMS-evoked thumb movements. The pre/post-training change in the direction of TMS-evoked thumb movements as well as the change in the first peak velocity of these thumb movements was used as an indication of the magnitude of adaptation following MI training. During the training session, participants imagined themselves moving their thumb in the opposite direction of the pre-determined dominant direction. Single-pulse TMS was also used to determine the amplitude of motor evoked potentials (MEPs) during imagined thumb movements. A strong positive relationship was found between MEP amplitude during MI of thumb movements and both measures of motor cortical adaptation following MI training. These results support the hypothesis that activation of the corticospinal motor system during MI of movements is related to the magnitude of motor cortical adaptations following MI training.

In this article, we challenge the usefulness of “attention” as a unitary construct and/or neural system. We point out that the concept has too many meanings to justify a single term, and that “attention” is used to refer to both the explanandum (the set of phenomena in need of explanation) and the explanans (the set of processes doing the explaining). To illustrate these points, we focus our discussion on visual selective attention. It is argued that selectivity in processing has emerged through evolution as a design feature of a complex multi-channel sensorimotor system, which generates selective phenomena of “attention” as one of many by-products. Instead of the traditional analytic approach to attention, we suggest a synthetic approach that starts with well-understood mechanisms that do not need to be dedicated to attention, and yet account for the selectivity phenomena under investigation. We conclude that what would serve scientific progress best would be to drop the term “attention” as a label for a specific functional or neural system and instead focus on behaviorally relevant selection processes and the many systems that implement them.

Humans use eye- and head-gaze cues to facilitate social interactions among members of their own species. Research examining nonhuman animal-to-human cueing effects has received little attention, but may provide valuable insight into the mechanisms that have enabled species to coexist and thrive in shared environments. The objective of the current studies was to determine how gaze cues influence the attention and target detection of humans when they view images of mammals (human, orangutan, and dog; Experiment 1) and aves (owl, macaw parrot, and duck; Experiment 2). Participants were presented with an image of a forward-facing head that was suddenly replaced with an image of the head facing to the left or right, creating an apparent head rotation and change of orientation. A target appeared randomly on the left or right side of the head-gaze cue after 1 of 4 stimulus-onset asynchronies (SOAs; 100, 300, 600, or 1,000 ms). Participants were asked to indicate the location of the target by pressing a spatially corresponding key. The analysis of response times (RTs) revealed facilitatory cueing effects (RTs to cued targets were shorter than to uncued targets) across all SOAs in Experiment 1 (images of mammals). Such facilitatory cueing effects were only present at short SOAs (i.e., 100 and 300 ms) in Experiment 2 (images of aves). These findings provide initial evidence that the processing of gaze cues observed during human-to-human interactions is similar to that observed during mammal-to-human interactions, but is different in aves-to-human interactions. Alternative interpretations of the data are discussed. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Biological motion is salient to the human visual and motor systems and may be intrinsic to the perception of animacy. Evidence for the salience of visual stimuli moving with trajectories consistent with biological motion comes from studies showing that such stimuli can trigger shifts of attention in the direction of that motion. The present study was conducted to determine whether or not top-down beliefs about animacy can modify the salience of a nonbiologically moving stimulus to the visuomotor system. A nonpredictive cuing task was used in which a white dot moved from a central location toward a left- or right-sided target placeholder. The target randomly appeared at either location 200, 600, or 1,300 ms after the motion onset. Five groups of participants experienced different stimulus conditions: (1) biological motion, (2) inverted biological motion, (3) nonbiological motion, (4) animacy belief (paired with nonbiological motion), and (5) computer-generated belief (paired with nonbiological motion). Analysis of response times revealed that the motion in the biological motion and animacy belief groups, but not in the inverted and nonbiological motion groups, affected processing of the target information. These findings indicate that biological motion is salient to the visual system and that top-down beliefs regarding the animacy of the stimulus can tune the visual and motor systems to increase the salience of nonbiological motion.

Self-prioritization is a robust phenomenon whereby judgments concerning self-representational stimuli are faster than judgments toward other stimuli. The present paper examines if and how self-prioritization causes more vivid short-term memories for self-related objects by giving geometric shapes arbitrary identities (self, mother, stranger). In Experiment 1 participants were presented with an array of the three shapes and required to retain the location and color of each in memory. Participants were then probed regarding the identity of one of the shapes and subsequently asked to indicate the color of the probed shape or an unprobed shape on a color wheel. Results indicated no benefit for self-stimuli in either response time for the identification probe or for color fidelity in memory. Yet, a cuing benefit was observed such that the cued stimulus in the identity probe did have higher fidelity within memory. Experiments 2 and 3 reduced the cognitive load by only requiring that participants process the identity and color of one shape at a time. For Experiment 2, the identity probe was memory-based, whereas the stimulus was presented alongside the identity probe for Experiment 3. Results demonstrated a robust self-prioritization effect: self-related shapes were classified faster than non-self-shapes, but this self-advantage did not lead to an increase in the fidelity of memory for self-related shapes’ colors. Overall, these results suggest that self-prioritization effects may be restricted to an improvement in the ability to recognize that the self-representational stimulus is present without devoting more perceptual and short-term memory resources to such stimuli.

Previous work has revealed that social cues, such as gaze and pointed fingers, can lead to a shift in the focus of another person’s attention. Research investigating the mechanisms of these shifts of attention has typically employed detection or localization button-pressing tasks. Because in-depth analyses of the spatiotemporal characteristics of aiming movements can provide additional insights into the dynamics of the processing of stimuli, in the present study we used a reaching paradigm to further explore the processing of social cues. In Experiments 1 and 2, participants aimed to a left or right location after a nonpredictive eye gaze cue toward one of these target locations. Seven stimulus onset asynchronies (SOAs), from 100 to 2,400 ms, were used. Both the temporal (reaction time, RT) and spatial (initial movement angle, IMA) characteristics of the movements were analyzed. RTs were shorter for cued (gazed-at) than for uncued targets across most SOAs. There were, however, no statistical differences in IMAs between movements to cued and uncued targets, suggesting that action planning was not affected by the gaze cue. In Experiment 3, the social cue was a finger pointing to one of the two target locations. Finger-pointing cues generated significant cueing effects in both RTs and IMAs. Overall, these results indicate that eye gaze and finger-pointing social cues are processed differently. Perception–action coupling (i.e., a tight link between the response and the social cue that is presented) might play roles in both the generation of action and the deviation of trajectories toward cued and uncued targets.

The original Barbie doll’s unrealistic body shape can negatively affect young girls’ body image. Mattel produced new Barbie dolls with “tall”, “curvy”, and “petite” body types, yet how girls perceive and evaluate the three new Barbie body types remains unknown. This study investigated whether young girls engage in an automatic “self-other matching” process when viewing the different Barbie doll representations. Female children and adolescents (N = 38; Mage = 10; 6–14 years old; SD = 2.24 years) completed a body-part compatibility task to provide an index of how they implicitly relate cognitive representations of their own body to the different doll images. Significant (p < .05) body-part compatibility effects emerged for the original, curvy and petite dolls, but not for the tall Barbie. These findings indicate that girls engage in a self-other body matching process when viewing Barbie, but that the strength of this matching is influenced by the doll’s body type. Results provide new evidence on the underlying cognitive mechanisms that occur when girls are exposed to physique-salient toys, and may have implications for young girls’ body image development and use of appearance-based social comparisons.

Purpose. This study aimed to determine whether untrained observers alter their spine as directed via static images of different lifting techniques. Methods. Ten men and eight women, who had no lift...

A large number of studies have now described the various ways in which the observation of another person’s dynamic movement can influence the speed with which the observer is able to prepare a motor action themselves. The typical results are most often explained with reference to theories that link perception and action. Such theories argue that the cognitive structures associated with each share common representations. Consequently, action preparation and action observation are often said to be functionally equivalent. However, the dominance of these theories in explaining action observation effects has masked the potential contribution from processes associated with the detection of low-level “transients” resulting from observing a body movement, such as motion and sound. In the present review, we describe work undertaken in one particular action observation phenomenon (“social inhibition of return”) and show that the transient account provides the best explanation of the effect. We argue that future work should consider attention capture and orienting as a potential contributing factor to action observation effects more broadly.

Attention can be shifted in the direction that another person is looking, but the role played by an observer's mental attribution to the looker is controversial. And whether mental attribution to the looker is sufficient to trigger an attention shift is unknown. The current study introduces a novel paradigm to investigate this latter issue. An actor is presented on video turning his head to the left or right before a target appears, randomly, at the gazed-at or non-gazed at location. Time to detect the target is measured. The standard finding is that target detection is more efficient at the gazed-at than the nongazed-at location, indicating that attention is shifted to the gazed-at location. Critically, in the current study, an actor is wearing two identical masks -- one covering his face and the other the back of his head. Thus, after the head turn, participants are presented with the profile of two faces, one looking left and one looking right. For a gaze cuing effect to emerge, participants must attribute a mental state to the actor -- as looking through one mask and not the other. Over the course of four experiments we report that when mental attribution is necessary, a shift in social attention does not occur (i.e., mental attribution is not sufficient to produce a social attention effect); and when mental attribution is not necessary, a shift in social attention does occur. Thus, mental attribution is neither sufficient nor necessary for the occurrence of an involuntary shift in social attention. The present findings constrain future models of social attention that wish to link gaze cuing to mental attribution.

Cyclical upper-limb movements involuntarily deviate from a primary movement direction when the actor concurrently observes incongruent biological motion. We examined whether environmental context influences such motor interference during interpersonal observation–execution. Participants executed continuous horizontal arm movements while observing congruent horizontal or incongruent curvilinear biological movements with or without the presence of an object positioned as an obstacle or distractor. When participants were observing a curvilinear movement, an object located within the movement space became an obstacle, and, thus, the curvilinear trajectory was essential to reach into horizontal space. When acting as a distractor, or with no object, the curvilinear trajectory was no longer essential. For observing horizontal movements, objects were located at the same relative locations as in the curvilinear movement condition. We found greater involuntary movement deviation when observing curvilinear than horizontal movements. Also, there was an influence of context only when observing horizontal movements, with greater deviation exhibited in the presence of a large obstacle. These findings suggest that the influence of environmental context is underpinned by the (mis-)matching of observed and executed actions as incongruent biological motion is primarily coded via bottom-up sensorimotor processes, whilst the congruent condition incorporates surrounding environmental features to modulate the bottom-up sensorimotor processes.

The social inhibition of return (sIOR) effect refers to the finding that response initiation times are longer if a movement is executed to a location where another person has responded to just before. Previous studies have examined the influence of the goal of the action on sIOR. In these studies, however, the movement endpoint and to-be-attained goal (e.g., touching/pressing a response key) were at the same spatial location. In the present two experiments, we disentangled movement endpoint and goal's identity and locations by means of introducing action effects that followed directly from a movement. Similar methods were previously shown powerful enough to clearly show the importance of action goals for other phenomena—a finding consistent with effect-based theories of action control, such as the ideomotor theory. The results of the present study revealed that sIOR was shaped by the movement endpoint location, not the goal's identity or location. That is, in both experiments, an sIOR effect was observed, but the magnitude of the sIOR effect was not modulated by repetitions/switches of goals or their locations. Thus, results indicate that goals play a negligible role in the emergence of the sIOR and, consequently, highlight the importance of action observation for the emergence of the sIOR effect.

When a person executes a movement, the movement is more errorful while observing another person's actions that are incongruent rather than congruent with the executed action. This effect is known as "motor contagion". Accounts of this effect are often grounded in simulation mechanisms: increased movement error emerges because the motor codes associated with observed actions compete with motor codes of the goal action. It is also possible, however, that the increased movement error is linked to eye movements that are executed simultaneously with the hand movement because oculomotor and manual-motor systems are highly interconnected. In the present study, participants performed a motor contagion task in which they executed horizontal arm movements while observing a model making either vertical (incongruent) or horizontal (congruent) movements under three conditions: no instruction, maintain central fixation, or track the model's hand with the eyes. A significant motor contagion-like effect was only found in the 'track' condition. Thus, 'motor contagion' in the present task may be an artifact of simultaneously executed incongruent eye movements. These data are discussed in the context of stimulation and associative learning theories, and raise eye movements as a critical methodological consideration for future work on motor contagion.

The utilization of visual information for the control of ongoing voluntary limb movements has been investigated for more than a century. Recently, online sensorimotor processes for the control of upper-limb reaches were hypothesized to include a distinct process related to the comparison of limb and target positions (i.e., limb-target regulation processes: Elliott et al. in Psychol Bull 136:1023–1044. doi: 10.1037/a0020958 , 2010). In the current study, this hypothesis was tested by presenting participants with brief windows of vision (20 ms) when the real-time velocity of the reaching limb rose above selected velocity criteria. One experiment tested the perceptual judgments of endpoint bias (i.e., under- vs. over-shoot), and another experiment tested the shifts in endpoint distributions following an imperceptible target jump. Both experiments revealed that limb-target regulation processes take place at an optimal velocity or “sweet spot” between movement onset and peak limb velocity (i.e., 1.0 m/s with the employed movement amplitude and duration). In contrast with pseudo-continuous models of online control (e.g., Elliott et al. in Hum Mov Sci 10:393–418. doi: 10.1016/0167-9457(91)90013-N , 1991), humans likely optimize online limb-target regulation processes by gathering visual information at a rather limited period of time, well in advance of peak limb velocity.

Fitts' Law holds that, to maintain accuracy, movement times of aiming movements must change as a result of varying degrees of movement difficulty. Recent evidence has emerged that aiming to a target located last in an array of placeholders results in a shorter movement time than would be expected by the Fitts' equation-a violation of Fitts' Law. It has been suggested that the violation emerges because the performer adopts an optimized movement strategy in which they partially pre-plan an action to the closest placeholder (undershoot the last placeholder) and rely on a secondary acceleration to propel the limb toward the last location when it is selected as the target (Glazebrook et al. in Hum Mov Sci 39:163-176, 2015). In the current study, we examine this proposal and further elucidate the processes underlying the violation by examining limb displacement and corrective submovements that occur when performers aim to different target locations. For our Main Study, participants executed discrete aiming movements in a five-placeholder array. We also reanalyzed data from a previously reported study in which participants aimed in placeholder and no-placeholder conditions (Blinch et al. in Exp Brain Res 223:505-515, 2012). The results showed the violation of Fitts' Law unfolded following peak velocity (online control). Further, the analysis showed that movements to the last target tended to overshoot and had a higher proportion of secondary submovements featuring a reversal than other categories of submovement (secondary accelerations, discontinuities). These findings indicate that the violation of Fitts' Law may, in fact, result from a strategic bias toward planning farther initial displacements of the limb which accommodates a shorter time in online control.