Infant's perception of goal-directed actions performed by a mechanical device

The present work investigated whether by the end of the first year, infants interpret actions performed by a mechanical device as goal-directed and why they would do so. Using a modified version of the Woodward (1998) habituation paradigm, 9- and 12-month-old infants were tested in a condition in which they saw a mechanical claw performing an action (Study 1). When infants viewed the claw grasping and transporting objects to the back of a stage, 12-month-old but not 9-month-old infants interpreted the action as goal-directed. In Study 2, 9-month-olds received prior to habituation an information phase showing infants how a human held and operated the claw. This enrichment of infants’ knowledge enabled 9-month-old infants to interpret the action display as goal-directed. The role of the developing means-end understanding and tool-use for infants’ interpretation of actions performed by a mechanical device is discussed.     

Resurgence of goal-directed actions and habits

This study investigated how goal-directed and habitual behaviors recover after extinction within the context of the resurgence effect, a form of relapse induced by the removal or worsening of alternative reinforcement. Rats were trained to press a target lever with one reinforcer (O1) for either minimal (4) or extended (16) sessions. An extinction test after the completion of O1 devaluation confirmed that minimal and extended training formed goal-directed and habitual behaviors, respectively. Then, pressing an alternative lever was reinforced with a second reinforcer (O2) while the target response was placed on extinction. When O2 was discontinued, the minimally trained target response resurged with goal-directed status as in the extinction test. However, the extinguished habitual behavior in the extensively trained rats did not recover as a habit but instead with goal-directed status, possibly due to the context specificity of habits or the introduction of a new response–reinforcer contingency. The critical finding that reinforcer devaluation consistently led to less resurgence regardless of the amount of acquisition training provides a clinical implication that coupling differential-reinforcement-of-alternative-behavior (DRA) treatments with the devaluation of the associated reinforcer of problematic behavior could effectively diminish its recurrence.     

Demonstrator skill modulates observational aversive learning

Learning to avoid danger by observing others can be relatively safe, because it does not incur the potential costs of individual trial and error. However, information gained through social observation might be less reliable than information gained through individual experiences, underscoring the need to apply observational learning critically. In order for observational learning to be adaptive it should be modulated by the skill of the observed person, the demonstrator. To address this issue, we used a probabilistic two-choice task where participants learned to minimize the number of electric shocks through individual learning and by observing a demonstrator performing the same task. By manipulating the demonstrator’s skill we varied how useful the observable information was; the demonstrator either learned the task quickly or did not learn it at all (random choices). To investigate the modulatory effect in detail, the task was performed under three conditions of available observable information; no observable information, observation of choices only, and observation of both the choices and their consequences. As predicted, our results showed that observable information can improve performance compared to individual learning, both when the demonstrator is skilled and unskilled; observation of consequences improved performance for both groups while observation of choices only improved performance for the group observing the skilled demonstrator. Reinforcement learning modeling showed that demonstrator skill modulated observational learning from the demonstrator’s choices, but not their consequences, by increasing the degree of imitation over time for the group that observed a fast learner. Our results show that humans can adaptively modulate observational learning in response to the usefulness of observable information.     

Newborns' preference for goal-directed actions

The central role of sensory-motor representations in cognitive functions is almost universally accepted. However, determining the link between motor execution and its sensory counterpart and when, during ontogenesis, this link originates are still under investigation. The aim of the present study is to investigate whether at birth this link is already present and 2-day-old newborns are able to discriminate between visual cues indicating goal-directed or non-goal-directed actions. Here, with a preferential looking technique, a hand grasping a ball was the observed movement and we orthogonally manipulated the three factors necessary to successfully reach the goal: (a) presence of the ball, (b) direction of the arm movement, and (c) hand shaping. Results indicated that newborns orient more frequently and look longer at a hand shape for whole hand prehension but only when the movement is directed away from the body and toward the external world. In addition, newborns prefer the away from the body movement only when the object is present. We argue that newborns prefer a movement directed toward the external world only when it may develop into a purposeful movement because of the presence of the to-be-grasped object. Overall, our results support the existence of primitive sensory-motor associations since the first days after birth.     

Behaviour and gaze analyses during a goal-directed locomotor task

The objectives of the current study were: (a) to determine whether perception–action coupling controlled behaviours when walking through moving doors and (b) to determine how vision contributed to this behaviour. Participants (N = 6) walked along a 7-m path toward two motor-driven doors, which moved at rates ranging between 20 and 40 cm/s. Each door was independently driven such that both moved at the same velocity (symmetrical) or at different velocities (asymmetrical). The results showed that in both door movement conditions the participants controlled their approach velocity by slowing down prior to crossing the doors. The decrease in walking velocity produced greater velocity variability in the final stages prior to crossing the doors and high success rates. The results from the gaze behaviours showed that fixation durations were significantly longer when the doors moved asymmetrically, suggesting that the visual information from this unpredictable environment took longer to process. However, the fixation patterns were similar between the two door movement conditions. Regardless of the door movement condition, the participants spent about 60% of each trial fixating environmental objects (i.e., left door, right door, or aperture). The majority of fixations were directed towards one of the doors at the beginning of the trial and then shifted towards the aperture in the final phase. The participants were using perception–action coupling to control their behaviours in the final phase in order to steer locomotion through the aperture.     

Goal relevance and artificial grammar learning

This investigation used a newly developed artificial grammar learning (AGL) paradigm in which participants were exposed to sequences of stimuli that varied in two dimensions (colours and letters) that were superimposed on each other. Variation within each dimension was determined by a different grammar. The results of two studies strongly suggest that implicit learning in AGL depends on the goal relevance of the to-be-learned dimension. Specifically, when only one of the two stimulus dimensions was relevant for their task (Experiment 1) participants learned the structure underlying the relevant, but not that of the irrelevant dimension. However, when both dimensions were relevant, both structures were learned (Experiment 2). These findings suggest that implicit learning occurs only in dimensions to which we are attuned. Based on the present results and on those of Eitam, Hassin, and Schul (2008) we suggest that focusing on goal relevance may provide new insights into the mechanisms underlying implicit learning.     

Visual monitoring of goal-directed aiming movements

Goal-directed movements are subject to intrinsic planning and execution variability, which requires that the central nervous system closely monitor our movements to ensure endpoint accuracy. In the present study, we sought to determine how closely the visual system monitored goal-directed aiming movements. We used a cursor-jump paradigm in which a cursor was unexpectedly translated soon after movement initiation. Some of the trials included a second cursor jump, and the cursor remained visible for different durations. The results indicate that seeing the cursor for only 16?ms after the second cursor jump was sufficient to influence the movement endpoint, which suggests that the visual system continuously monitored goal-directed movements. The results also suggest that the perceived position/trajectory of the effector was likely to have been averaged over a period of approximately 70?ms.     

Beyond the information given: Infants’ transfer of actions learned through imitation

Five experiments were conducted to investigate infants’ ability to transfer actions learned via imitation to new objects and to examine what components of the original context are critical to such transfer. Infants of 15 months observed an experimenter perform an action with one or two toys and then were offered a novel toy that was not demonstrated for them. In all experiments, infants performed target actions with the novel toy more frequently than infants who were offered the same toy but had seen no prior demonstrations. Infants exhibited transfer even when the specific part to be manipulated looked different across the toys, even when they had not performed the actions with the demonstration toys themselves, even when the actions produced no effects on the demonstrations, and even when the actions were demonstrated with only a single exemplar toy. Transfer was especially robust when infants not only observed but also practiced the target actions on the demonstration trials. Learning action affordances (“means”) seems to be a central aspect of human imitation, and the propensity to apply these learned action affordances in new object contexts may be an important basis for technological innovation and invention.     

The influence of adults' actions on children's inferences about word meanings

This article first establishes the effect of adults' actions on children's inferences about the shape and material of solid objects, based on data from Japanese 2-, 4-, and 6-year-olds. Japanese 2-year-olds are already sensitive to adults' actions in making inferences, and children become more adept at this as they become older. The invariance of the phenomenon of the effect of actions is then discussed in terms of three of its aspects: across age groups, across languages (the universality of the effect), and across tasks in lexical development. It is suggested that while specific linguistic characteristics (e.g., the means of individuation of entities), and complexity of object shape probably influence the effect of actions, action effects may have a potentially invariant/universal aspect.     

Twelve-month-olds' understanding of prior actions and final goals

Twelve-month-olds were habituated to trials in which a grasping action preceded the holding of an object. Infants recovered looking to test events when a new object was held, but only when this was preceded by prior contact with the object.     

Gradations of emulation learning in infants' imitation of actions on objects

This study explored different gradations of emulation in the imitation of actions on objects by 17-month-olds. Experiment 1 established levels of behavioral reproduction following prerecorded video demonstrations similar to those levels following live demonstrations. In Experiment 2, two digitally modified videos, where object movements or body movements critical to producing the target action were highlighted in isolation, were developed. Infants produced the target action equally frequently by observing the object movement video and observing the unmodified video. In contrast, their performance was much less successful based on the body movement video. In Experiment 3, the performance obtained following the object movement video was similar to that following a further video that emphasized the object movements produced in unsuccessful attempts to produce the target action. These findings suggest that emulation in the form of object movement reenactment or affordance learning plays a role in the social learning of actions on objects during infancy.     

Side-effect actions,acting for a reason,and acting intentionally

What is the relation between acting intentionally and acting for a reason? While this question has generated a considerable amount of debate in the philosophy of action, on one point there has been a virtual consensus: actions performed for a reason are necessarily intentional. Recently, this consensus has been challenged by Joshua Knobe and Sean Kelly, who argue against it on the basis of empirical evidence concerning the ways in which ordinary speakers of the English language describe and explain certain side-effect actions. Knobe and Kelly's argument is of interest not only because it challenges a widely accepted philosophical thesis on the basis of experimental evidence, but also because it indirectly raises an important and largely neglected question, the question of whether or in what sense an agent can perform a side-effect action for a reason. In this article, I address this question and provide a positive answer to it. Specifically, I argue that agents act for a reason whenever they perform side-effect actions as trade-offs. Thus, I claim that there are three distinct types of rational action: actions performed as ends in themselves, actions performed as means to further ends, and side-effect actions performed as trade-offs. Given this multiplicity of types of rational action, the question of whether or not actions performed for a reason are necessarily intentional is in need of refinement. The more specific question that lies at the heart of this article is whether or not side-effect actions performed as trade-offs are necessarily intentional. I conclude that, contrary to what Knobe and Kelly suggest, the question remains open.     

Temporal perception is enhanced for goal-directed biological actions

ABSTRACT

Research into the visual perception of goal-directed human action indicates that human action perception makes use of specialized processing systems, similar to those that operate in visual expertise. Against this background, the current research investigated whether perception of temporal information in goal-directed human action is enhanced relative to similar motion stimuli. Experiment 1 compared observers’ sensitivity to speed changes in upright human action to a kinematic control (an animation yoked to the motion of the human hand), and also to inverted human action. Experiment 2 compared human action to a non-human motion control (a tool moved the object). In both experiments observers’ sensitivity to detecting the speed changes was higher for the human stimuli relative to the control stimuli, and inversion in Experiment 1 did not alter observers’ sensitivity. Experiment 3 compared observers’ sensitivity to speed changes in goal-directed human and dog actions, in order to determine if enhanced temporal perception is unique to human actions. Results revealed no difference between human and dog stimuli, indicating that enhanced speed perception may exist for any biological motion. Results are discussed with reference to theories of biological motion perception and perception in visual expertise.     

Conscious awareness of action potentiates sensorimotor learning

Many everyday skills are unconsciously learned through repetitions of the same behaviour by binding independent motor acts into unified sets of actions. However, our ability to be consciously aware of producing newly and highly trained motor skills raises the question of the role played by conscious awareness of action upon skill acquisition. In this study we strengthened conscious awareness of self-produced sequential finger movements by way of asking participants to judge their performance in terms of maximal fluency after each trial. Control conditions in which participants did not make any judgment or performance-unrelated judgments were also included. Findings indicate that conscious awareness of action, enhanced via subjective appraisal of motor efficiency, potentiates sensorimotor learning and skilful motor production in optimising the processing and sequencing of action units, as compared to the control groups. The current work lends support to the claim that the learning and skilful expression of sensorimotor behaviours might be grounded upon our ability to be consciously aware of our own motor capability and efficiency.     

From movements to actions: two mechanisms for learning action sequences

When other individuals move, we interpret their movements as discrete, hierarchically-organized, goal-directed actions. However, the mechanisms that integrate visible movement features into actions are poorly understood. Here, we consider two sequence learning mechanisms – transitional probability-based (TP) and position-based encoding computations – that have been studied extensively in the domain of language learning, and investigate their potential for integrating movements into actions. If these learning mechanisms integrate movements into actions, then they should create memory units that contain (i) movement information, (ii) information about the order in which movements occurred, and (iii) information allowing actions to be recognized from different viewpoints. We show that both mechanisms retain movement information. However, only the position-based mechanism creates movement representations that are view-invariant and contain order information. The TP-based mechanism creates movement representations that are view-dependent and contain no order information. We therefore suggest that the TP-based mechanism is unlikely to play an important role for integrating movements into actions. In contrast, the position-based mechanism retains some of the types of information needed to represent goal-directed actions, which makes it an attractive target for further research to explore what, if any, role it plays in the perception of goal-directed actions.     

Creating nonbelieved memories for bizarre actions using an imagination inflation procedure

The current experiments examined the creation of nonbelieved true and false memories after imagining bizarre and familiar actions using the imagination inflation procedure (Goff & Roediger, 1998). In both experiments, participants took part in three sessions. In Session 1, participants had to perform or imagine simple familiar actions (e.g., “stir the water with the spoon”) and bizarre actions (e.g., “balance the spoon on your nose”). A day later, participants needed to imagine simple actions of which some were new actions, and some were old actions that appeared in the first session. After a week, the participants completed a recognition task. For those actions that were correctly or incorrectly remembered as having been performed, the participant was challenged that the action was not performed in order to evoke nonbelieved true and false memories. In general, we found that the imagination inflation procedure can successfully induce participants to produce nonbelieved memories. In Study 1, we successfully induced nonbelieved memories for bizarre actions, although in general nonbelieved memory rates were low. In Study 2, more participants formed nonbelieved memories for bizarre actions than for familiar actions. Also, we found that especially belief was more susceptible to revision when memories were challenged than recollection. In two experiments, we showed that nonbelieved memories can successfully be induced for both familiar and bizarre actions.     

Rationales in children’s causal learning from others’ actions

Shown commensurate actions and information by an adult, preschoolers’ causal learning was influenced by the pedagogical context in which these actions occurred. Four-year-olds who were provided with a reason for an experimenter’s action relevant to learning causal structure showed more accurate causal learning than children exposed to the same action and data accompanied by an inappropriate rationale or accompanied by no explanatory information. These results suggest that children’s accurate causal learning is influenced by contextual factors that specify the instructional value of others’ actions.     

Emotionally guiding our actions

If emotions have a rational role in action, then one challenge for accounting for how we can act rationally when acting emotionally is to show how we can guide our actions by our emotional considerations, seen as reasons. In this paper, I put forward a novel proposal for how this can be so. Drawing on the interconnection between emotions, cares and caring, I argue that, as the emotional agent is a caring agent, she can be aware of the emotional consideration as a pro tanto reason favouring an action choice and, even, as the reason for which she should act.