توانایی نوزادان برای اتصال نگاه و ابراز هیجانی برای اقدام عامدانه

Abstract Four studies investigated whether and when infants connect information about an actor's affect and perception to their action. Arguably, this may be a crucial way in which infants come to recognize the intentional behaviors of others. In Study 1 an actor grasped one of two objects in a situation where cues from the actor's gaze and expression could serve to determine which object would be grasped, specifically the actor first looked at and emoted positively about one object but not the other. Twelve-month-olds, but not 8-month-olds, recognized that the actor was likely to grasp the object which she had visually regarded with positive affect. Studies 2, 3, and 4 replicated the main finding from Study 1 with 12- and 14-month-olds and included several contrasting conditions and controls. These studies provide evidence that the ability to use information about an adult's direction of gaze and emotional expression to predict action is both present, and developing at the end of the first year of life.

. Introduction How do infants understand the behavior of the people around them? A crucial task involves understanding people in intentional terms as adults do. In the larger sense, adults see people as having intentional mental states, e.g. beliefs about the world, desires for things. In the narrower, everyday sense they construe actions as purposive and goal-directed. What are the origins of this intentional understanding? Over the last 10 years research has demonstrated that preschoolers and toddlers share this “intentional stance” – thus, they employ a variety of intentional mental-state constructs to reason about persons' actions (e.g. Lillard & Flavell, 1990); they conversationally describe and explain human behavior in terms of what the person “wants”, “thinks”, and “knows” (e.g. Bartsch & Wellman, 1995); and they distinguish intended voluntary actions from unintended biological or physical movements such as a person shaking with fever or being blown down by the wind (e.g. Inagaki and Hatano, 1993 and Schult and Wellman, 1997). Recent findings suggest that even 1.5- and 2-year-olds are able to reason about persons' intentions ( Baldwin, 1991, Carpenter et al., 1998, Meltzoff, 1995 and Repacholi and Gopnik, 1997). What remains to be investigated are earlier developments, specifically infants' understanding of intentional states and acts. Our research is guided by a general framework for addressing this question. We acknowledge, as philosophers and psychologists have long pointed out, that action can be described at several contrasting levels, for instance, behavioral motions of the body vs. intentional actions. Behavioral features are not essential to intentions: one can intend to do something but then not do it; an intentional and non-intentional movement can appear behaviorally identical. While not essential to intentional action, nonetheless, certain perceivable features (overt movements and expressions) can often help identify a behavior as intentional. These features serve to signal a behavior's underlying intentionality – that this behavior is an intentional action – and thus can work to identify intentions, because intentions, when enacted, often (though not always) yield behaviors of a certain form. If so, what features of perceivable behavior, both movements and expressions, might plausibly indicate and manifest intentionality? And of these which might be detected by infants? There are several candidates (see e.g. Baldwin & Baird, 1999) but we concentrate on two: intentional acts are often directed toward certain target objects, and behavioral movements often systematically relate to the actor's gaze, facial expressions, and vocalizations. Intentional actions, in many simple situations involving actions on objects, can manifest a distinctive directedness to specific objects, reflective of the intention's underlying goal-directedness. We will term this object-directedness. Specifically, when an agent acts intentionally toward an object the movement dynamics often result in an approach to (or avoidance of) the object, or contact with, acquisition of, consumption of the object. Thus, in simple action situations at least – a person reaching for an ice cream cone, a hand pulling a cup towards a body, a child grasping a toy – the goal-directedness of intentions can result in a perceptually identifiable object-directedness manifest in behavior. Beyond object-directed movement itself, an intentional actor often manifests other characteristic movements, expressions, and postures. Consider reaching for and grasping a toy. Typically, such behavior requires perceptual apprehension and then guidance – manifest in head and eye orientations and trajectories. Launching the reach and guiding it might be manifest in a furrowed brow of concentration. If the intention is positive and to approach the object it can be preceded by and manifest in distinctive facial expressions – those associated with interest, pleasure, anticipation. Vocal accompaniments also often co-occur – “There”, “yes!”, “ahh”. If the intention is negative, this can be manifest in fearful, displeased, avoidant expressions and vocalizations. Actually obtaining the target object can result in distinctive facial expressions – those associated with happiness at success, or surprise at an unexpected result. We will term these various potential connections between target movements and other facial-vocal displays functionalconnections. This term seems apt because, for the actor, the target action is not simply associated with or conjoined with other concomitant behaviors and displays; the connections are indeed more functional. Thus, intentional grasps often require visual apprehension and guidance and hence certain visual orientations by the actor. And intentional actions often result from and result in certain emotional-cognitive reactions in the actor which are, often, manifest in facial or verbal expressions. In total, we propose that the object-directedness of behavior and the functional connections between the target action and other aspects of the person, especially their visual-emotional regard and expressions, can often manifest and potentially identify intentions. Consequently, one way to research infants' initial intentional understandings is to research infants' understanding of the object-directedness and functional connections manifest in human action. In the current research we focus on infants' recognition of connections between actors' actions and their perceptual-emotional displays. Although there is a long history of inquiry into infant social awareness, recently researchers have developed methods to more precisely examine infants' systematic conceptions of people by extending preferential looking time methods used to investigate infants' understanding of the physical world (e.g. Baillargeon, 1993 and Spelke et al., 1992) to their understanding of the social world (e.g. Woodward, 1998). Several recent studies of this sort have shown that 6-, 9- and 12-month-olds appreciate important features of how behaviors (e.g. a reach) can be object-directed (Phillips and Wellman, 2002, Sodian and Thoermer, 2001 and Woodward, 1998). But these studies do not address whether and when infants also appreciate the telltale connections between the target action and other relevant perceptual and emotional features of the actor. Of course, much research, such as that on social referencing, indicates that infants at least sometimes pay attention to relevant perceptual-emotional cues in others. For example, infants pay attention to and discriminate emotional expressions in the first year. Newborns may show some discrimination of happy vs. sad living faces (Field & Walden, 1982). Two-month-old infants imitate facial expressions of happiness, sadness, and surprise (Field, Vega-Lahar, Scafidi & Goldstein, 1986). Five-month-old infants generalize from one set of actors portraying happy or sad emotions to new actors portraying these emotions (Caron, Caron, & MacLean, 1988). In these and other ways infants come to discriminate facial expressions of a variety of emotions in the first half year of life (Nelson, 1987). Moreover, 2-month-olds react in systematic and appropriate ways to maternal expressions of joy, sadness, and anger (Haviland & Lelwica, 1987) and throughout the first year infants are upset in “still-face” research when persons do not behave actively and expressively (see review by Muir & Hains, 1993). In addition, infants can be sensitive to others' direction of gaze. Young infants preferentially attend to faces, particularly eyes, by about 2 months of age (Banks and Salapatek, 1983, Haith et al., 1977 and Johnson and Morton, 1991). There is at least some evidence that by the first half year infants not only attend to eyes but to gaze direction (Hood et al., 1998 and Vicera and Johnson, 1995). By 6 months, infants are beginning to look in the direction of gaze, if it is signaled by both eyes and head turning (Butterworth & Cochran, 1980). Infants' abilities to follow an adult's line of regard becomes more accurate between 6 and 12 months. For instance, when their mothers sit in front of them and turn their heads by 90 degrees, most 8- to 10-month-olds and almost all 11- to 14-month-olds will turn their heads in the same direction (Butterworth and Grover, 1998 and Scaife and Bruner, 1975). Even then, though, the younger infants will stop at the first object in their line of sight, even if the adult is looking farther off. It is not until 12 months that infants are able to extrapolate from their mothers' visual angle and fixate on the same object, thus achieving joint reference (Butterworth & Grover, 1998). Certainly, by 12 months, infants often are able to achieve joint reference, and they also show effects of social referencing to adults' emotional displays about objects (Bakeman and Adamson, 1984, Hornick et al., 1987 and Walden and Ogan, 1988). This competence in and of itself does not, however, tell us how infants are understanding the visual-emotional referential acts of adults. For example, in a social referencing situation the infant sees his mother express a facial emotion of fear toward an object and then tends to play less with that object. The mother's expression clearly controls the baby's behavior, but this does not show that the infant understands the mother's expression as being connected to, or predicting, the mother's intentional action. Following the mother's direction of gaze similarly may not involve an understanding of perceptual acts as intentional (as purposely directed toward objects) or as connected to intentional actions. Butterworth (1991), for example, who has conducted many of the studies of infants' ability to accurately follow gaze direction argues that until 18 months or so, infants solve such problems “geometrically”, based on simply following line of sight. (See the related arguments in Baldwin and Moses (1996) and Moore and Corkum (1994).) More generally, that infants can attend to gaze direction and emotion does not necessarily mean that they understand emotional-visual regard as connected to object-directed behavior, or that they use information about others' emotion and direction of gaze to assess or predict their action. Our research addresses these issues by exploring infants' recognition that emotional expression and visual regard connect to and thus can predict action. As we noted at the start, the term “intentional” has two related senses. In the everyday sense, actions are intentional in being purposive and goal-directed. In the philosophical sense, mental states, such as beliefs and desires, are intentional in being about something – for example, a belief about apples or a desire for apples. Our research includes features that, potentially, relate to both these senses of intentionality. Our displays present purposeful actions to infants. However, the displays also present emotionally valenced visual regard. For adults, such visual regard signals aboutness – the actor's desire for or preferences about the thing regarded.