When does an ostrich become a bird? The role of typicality in early word comprehension.

Which objects and animals are children willing to accept as referents for words they know? To answer this question, the authors assessed early word comprehension using the preferential looking task. Children were shown 2 stimuli side by side (a target and a distractor) and heard the target stimulus named. The target stimulus was either a typical or an atypical exemplar of the named category. It was predicted that children first connect typical examples with the target name and broaden the extension of the name as they get older to include less typical examples. Experiment 1 shows that when targets are named, 12-month-olds display an increase in target looking for typical but not atypical targets whereas 24-month-olds display an increase for both. Experiment 2 shows that 18-month-olds display a pattern similar to that of 24-month-olds. Implications for the early development of word comprehension are discussed.     

Sharing attention and pointing to objects at 12 months: is the intentional stance implied?

The goal of the present research was to assess whether communicative gestures, such as gazing and declarative pointing of 12-month-old infants indicate that infants perceive people as intentional agents, or whether infant communicative behaviors are merely triggered by specific perceptual cues in joint visual attention situations. Two experiments were conducted. In Experiment 1, thirty-two 12-month-olds were conditioned to follow the gaze of a contingently interacting person or object. They were then submitted to a paradigm designed to incite them to initiate communicative gestures to the person or object. The temporal coordination between pointing, gazing, and vocalizations occurred at a significantly higher rate in the Person than in the Object condition. In Experiment 2, the effect of the attentional focus of others on the gaze, points and vocalizations of thirty 12-month-olds was investigated. Infants were assessed in conditions where the experimenter vocalized while looking at the same (In-focus), or a different (Out-of-focus) toy than the infants. Infants who pointed produced more co-occurrences of gaze, vocalizations and points in the Out-of-focus condition than in the In-focus condition. Thus, by 12 months, infants are aware of the attentional state of the person. Discussion centers on the implications of these findings for theories of social and cognitive knowing.     

Is visual reference necessary? Contributions of facial versus vocal cues in 12‐month‐olds’ social referencing behavior

To examine the influences of facial versus vocal cues on infants' behavior in a potentially threatening situation, 12-month-olds on a visual cliff received positive facial-only, vocal-only, or both facial and vocal cues from mothers. Infants' crossing times and looks to mother were assessed. Infants crossed the cliff faster with multimodal and vocal than with facial cues, and looked more to mother in the Face Plus Voice compared to the Voice Only condition. The findings suggest that vocal cues, even without a visual reference, are more potent than facial cues in guiding infants' behavior. The discussion focuses on the meaning of infants' looks and the role of voice in development of social cognition.     

The effect of positive emotion on infants' gaze shift

Infants often voluntarily glance at their social partner during their toy play, disengaging their gaze from a toy and selecting a caregiver as their new looking target. This study posed two research questions: Do positive emotions disengage infants' gaze from their point of fixation, and do positive emotions facilitate the selection of the caregiver as their next looking target? The rate of gaze shifts was calculated for neutral and positive emotional states during their toy play. Across all ages, infants exhibited more disengagement from their point of fixation in the positive state than in the neutral one. However, 6- and 9-month-old infants revealed no difference in selecting a caregiver or a physical object as their next looking target in the positive state, but 12-month-olds increased gazing at caregivers in the positive state. These results were discussed with regard to the role of positive emotions on the development of infants' initiating joint attention.     

Development of preferences for the human body shape in infancy

Two studies investigated the development of infants' visual preferences for the human body shape. In Study 1, infants of 12, 15 and 18 months were tested in a standard preferential looking experiment, in which they were shown paired line drawings of typical and scrambled bodies. Results indicated that the 18-month-olds had a reliable preference for the scrambled body shapes over typical body shapes, while the younger infants did not show differential responding. In Study 2, 12- and 18-month-olds were tested with the same procedure, except that the typical and scrambled body stimuli were photographic images. The results of Study 2 again indicated that only the 18-month-olds had a reliable preference for the scrambled body shapes. This finding contrasts sharply with infants' precocious preferences for human faces, suggesting that infants' learning about human faces and human bodies follow different developmental trajectories.     

Effects of gesture and target on 12- and 18-month-olds' joint visual attention to objects in front of or behind them

Factors affecting joint visual attention in 12- and 18-month-olds were investigated. In Experiment 1 infants responded to 1 of 3 parental gestures: looking, looking and pointing, or looking, pointing, and verbalizing. Target objects were either identical to or distinctive from distractor objects. Targets were in front of or behind the infant to test G. E. Butterworth's (1991b) hypothesis that 12-month-olds do not follow gaze to objects behind them. Pointing elicited more episodes of joint visual attention than looking alone. Distinctive targets elicited more episodes of joint visual attention than identical targets. Although infants most reliably followed gestures to targets in front of them, even 12-month-olds followed gestures to targets behind them. In Experiment 2 parents were rotated so that the magnitude of their head turns to fixate front and back targets was equivalent. Infants looked more at front than at back targets, but there was also an effect of magnitude of head turn. Infants' relative neglect of back targets is partly due to the "size" of adult's gesture.     

Longitudinal attentional engagement rescues mice from age-related cognitive declines and cognitive inflexibility

Learning, attentional, and perseverative deficits are characteristic of cognitive aging. In this study, genetically diverse CD-1 mice underwent longitudinal training in a task asserted to tax working memory capacity and its dependence on selective attention. Beginning at 3 mo of age, animals were trained for 12 d to perform in a dual radial-arm maze task that required the mice to remember and operate on two sets of overlapping guidance (spatial) cues. As previously reported, this training resulted in an immediate (at 4 mo of age) improvement in the animals' aggregate performance across a battery of five learning tasks. Subsequently, these animals received an additional 3 d of working memory training at 3-wk intervals for 15 mo (totaling 66 training sessions), and at 18 mo of age were assessed on a selective attention task, a second set of learning tasks, and variations of those tasks that required the animals to modify the previously learned response. Both attentional and learning abilities (on passive avoidance, active avoidance, and reinforced alternation tasks) were impaired in aged animals that had not received working memory training. Likewise, these aged animals exhibited consistent deficits when required to modify a previously instantiated learned response (in reinforced alternation, active avoidance, and spatial water maze). In contrast, these attentional, learning, and perseverative deficits were attenuated in aged animals that had undergone lifelong working memory exercise. These results suggest that general impairments of learning, attention, and cognitive flexibility may be mitigated by a cognitive exercise regimen that requires chronic attentional engagement.     

Multisensory exploration and object individuation in infancy

Recent research indicates that by 4.5 months, infants use shape and size information as the basis for individuating objects but that it is not until 11.5 months that they use color information for this purpose. The present experiments investigated the extent to which infants' sensitivity to color information could be increased through select experiences. Five experiments were conducted with 10.5- and 9.5-month-olds. The results revealed that multimodal (visual and tactile), but not unimodal (visual only), exploration of the objects prior to the individuation task increased 10.5-month-olds' sensitivity to color differences. These results suggest that multisensory experience with objects facilitates infants' use of color information when individuating objects. In contrast, 9.5-month-olds did not benefit from the multisensory procedure; possible explanations for this finding are explored. Together, these results reveal how an everyday experience--combined visual and tactile exploration of objects--can promote infants' use of color information as the basis for individuating objects. More broadly, these results shed light on the nature of infants' object representations and the cognitive mechanisms that support infants' changing sensitivity to color differences.     

Young infants reach correctly in A-not-B tasks: on the development of stability and perseveration

This paper examines the development of perseverative reaching in the A-not-B task. We describe two recent models that view perseveration as a sign of developmental progress toward stability. In Experiment 1, we test the novel prediction from both models that very young infants should not perseverate in the A-not-B task whereas older infants should. We tracked infants' behavior monthly on the A-not-B task and found that infants reached correctly at 5 months, and only perseverated at 7 and 8 months of age. Experiment 2 provides further evidence on the role of motor development in the emergence of perseveration by exploring the connection between perseveration and detailed changes in reach kinematics in two infants across the first year. These data together suggest that perseveration is a sign of developmental achievement on the path to stable and flexible behavior.     

工作记忆表征的激活与抑制状态对注意引导效应的影响

本研究采用双任务范式, 通过定向遗忘任务操纵工作记忆表征状态, 分别在目标无关和目标相关条件下考察工作记忆激活与抑制状态对视觉搜索早期注意引导效应的影响。实验1与实验2发现当工作记忆表征只可能与视觉搜索分心物匹配时(目标无关条件), 处于激活状态的工作记忆表征会引导视觉注意偏向到与之匹配的分心物, 表现出注意引导效应, 而处于抑制状态的工作记忆表征则没有观察到注意引导效应。实验3与实验4发现, 当工作记忆表征有可能与视觉搜索目标匹配时(目标相关条件), 处于激活状态的工作记忆表征能捕获注意, 而处于抑制状态的工作记忆表征只有与视觉搜索目标匹配时, 才表现出对该搜索目标反应的延迟。这些研究的结果表明(1)处于激活状态的工作记忆表征能有效地引导注意偏向到与之匹配的搜索目标或分心物, 并且这种注意引导效应并未受到抑制动机的影响而被消除或反转; (2)处于抑制状态的工作记忆表征能将抑制状态传递到视觉搜索阶段, 并延迟对与之匹配的搜索目标的反应。     

Cognitive flexibility in preschoolers: the role of representation activation and maintenance

Preschoolers' lack of cognitive flexibility has often been attributed to perseverative processing. This study investigates alternative potential sources of difficulty such as deficits in activating previously ignored information and in maintaining currently relevant information. In Experiment 1, a new task tapping attentional switching was designed to isolate the difficulty of overriding an initial representation, that is, perseverative processing ('Perseveration' version), and the difficulty of activating a previously ignored representation, that is, activation deficit ('Activation-deficit' version). Three-year-olds' performance suggested that inflexibility may primarily stem from an activation deficit. Control experiments confirmed that the difficulty of the 'Activation-deficit' version could not be attributed to the effect of attraction to novelty. In Experiment 2, 'distraction' errors, alleged to reflect a failure to maintain a relevant representation, and 'perseverative' errors were distinguished. The results highlighted the important role of representation maintenance in flexibility. The present study indicates that preschoolers' lack of cognitive flexibility is multi-determined and prompts us to reconsider the role of perseveration.     

The development of a word-learning strategy

Two studies investigated young infants' use of the word-learning principle Mutual Exclusivity. In Experiment 1, a linear relationship between age and performance was discovered. Seventeen-month-old infants successfully used Mutual Exclusivity to map novel labels to novel objects in a preferential looking paradigm. That is, when presented a familiar and a novel object (e.g. car and phototube) and asked to "look at the dax", 17-month-olds increased looking to the novel object (i.e. phototube) above baseline preference. On these trials, 16-month-olds were at chance. And, 14-month-olds systematically increased looking to the familiar object (i.e. car) in response to hearing the novel label "dax". Experiment 2 established that this increase in looking to the car was due solely to hearing the novel label "dax". Several possible interpretations of the surprising form of failure at 14 months are discussed.     

工作记忆与知觉负载对工作记忆表征引导注意的调节

本研究采用4个眼动实验探讨不同知觉负载条件下的视觉搜索任务中工作记忆负载对基于工作记忆表征的注意引导效应的影响。实验1和实验3采用低知觉负载的视觉搜索任务,结果在视觉工作记忆负载为1和2时观察到了显著的注意引导效应,但当负载增加到4时注意引导效应消失了;实验2和实验4采用高知觉负载的视觉搜索任务,结果发现注意引导效应在工作记忆负载增加到2时就已经消失了。上述结果表明:工作记忆负载和知觉负载都能够通过调控认知资源的方式来影响工作记忆表征对注意的引导,当认知资源充足时,工作记忆能够同时保持多个记忆表征对视觉注意的引导。     

A secret agent? How infants learn about the identity of objects in a causal scene

Four experiments examined the role of correlations between dynamic and static parts on 12- to 16-month-olds' ability to learn the identity of agents and recipients in a simple causal event. Infants were habituated to events in which objects with a dynamic or static part acted as an agent or a recipient and then were tested with an event in which the part-causal role relations were switched. Experiment 1 revealed that 16-month-olds, but not 12-month-olds, associate a dynamic part with the role of agent and a static part with the role of recipient. Experiment 2 showed that 12- and 16-month-olds do not associate a static part with the role of agent or a dynamic part with the role of recipient. Experiment 3 demonstrated that 14-month-olds will learn the relations presented in Experiment 1 and Experiment 2. Experiment 4 revealed that 12-month-olds were able to discriminate the two geometric figures in the events. The results are discussed with respect to infants' developing ability to attend to correlations between dynamic and static cues and the mechanism underlying early object concept acquisition.     

Attentional control in OCD and GAD: specificity and associations with core cognitive symptoms

Obsessive–compulsive disorder (OCD) and generalized anxiety disorder (GAD) are both defined by excessive negatively-valenced cognitions. Although obsessional thoughts are considered essential to OCD and perseverative worry is considered essential to GAD, these excessive cognitions have been found to co-occur in both disorders. Accordingly, a common diathesis may influence the emergence of excessive thoughts in both disorders. The present study examined deficits in attentional control as a cognitive vulnerability that may contribute to both obsessional thought and perseverative worry. Patients with OCD (n = 30), GAD (n = 29), and non-clinical controls (NCC; n = 29) completed measures of obsessional thoughts, perseverative worry, and attentional control. Deficits in self-reported attentional control were found in both OCD and GAD relative to the NCC. However, attentional control was only related to excessive cognition in the GAD patient group, where deficits were associated with increased perseverative worry. Mediational modeling suggested that trait anxiety mediated the relationship between attentional control and perseverative worry in GAD. Implications of these findings for conceptualizing the role of attentional control in the genesis of excessive cognitions in OCD and GAD are discussed.     

On the origin of the understanding of time, speed, and distance interrelations

We examined 18- and 24-month-old infants' sensitivity to the functional relationships between time, speed, and distance. The task included a train moving first visibly and then into a tunnel. The movement of the train was always accompanied by a train-characteristic sound signalling the travel duration. After the train concluded its travel, infants were requested to search for it in two possible locations inside the tunnel. Infants' reaching and head turn behavior indicated that 24-month-olds were sensitive to time-speed-distance interrelations, while 18-month-olds showed no such understanding. Reducing occlusion duration (by shortening the tunnel's length) revealed an increase in 18-month-olds' reaching and anticipatory head turns. Results are discussed in terms of the developmental course of the understanding of time-speed-distance interrelations and the strength of infants' representations.     

The development of gaze following and its relation to language

We examined the ontogeny of gaze following by testing infants at 9, 10 and 11 months of age. Infants (N = 96) watched as an adult turned her head toward a target with either open or closed eyes. The 10- and 11-month-olds followed adult turns significantly more often in the open-eyes than the closed-eyes condition, but the 9-month-olds did not respond differentially. Although 9-month-olds may view others as 'body orienters', older infants begin to register whether others are 'visually connected' to the external world and, hence, understand adult looking in a new way. Results also showed a strong positive correlation between gaze-following behavior at 10-11 months and subsequent language scores at 18 months. Implications for social cognition are discussed in light of the developmental shift in gaze following between 9 and 11 months of age.     

Rejecting salient distractors: Generalization from experience

Distraction impairs performance of many important, everyday tasks. Attentional control limits distraction by preferentially selecting important items for limited-capacity cognitive operations. Research in attentional control has typically investigated the degree to which selection of items is stimulus-driven versus goal-driven. Recent work finds that when observers initially learn a task, the selection is based on stimulus-driven factors, but through experience, goal-driven factors have an increasing influence. The modulation of selection by goals has been studied within the paradigm of learned distractor rejection, in which experience over a sequence of trials enables individuals eventually to ignore a perceptually salient distractor. The experiments presented examine whether observers can generalize learned distractor rejection to novel distractors. Observers searched for a target and ignored a salient color-singleton distractor that appeared in half of the trials. In Experiment 1, observers who learned distractor rejection in a variable environment rejected a novel distractor more effectively than observers who learned distractor rejection in a less variable, homogeneous environment, demonstrating that variable, heterogeneous stimulus environments encourage generalizable learned distractor rejection. Experiments 2 and 3 investigated the time course of learned distractor rejection across the experiment and found that after experiencing four color-singleton distractors in different blocks, observers could effectively reject subsequent novel color-singleton distractors. These results suggest that the optimization of attentional control to the task environment can be interpreted as a form of learning, demonstrating experience’s critical role in attentional control.     

Altering attentional control settings causes persistent biases of visual attention

Attentional control settings have an important role in guiding visual behaviour. Previous work within cognitive psychology has found that the deployment of general attentional control settings can be modulated by training. However, research has not yet established whether long-term modifications of one particular type of attentional control setting can be induced. To address this, we investigated persistent alterations to feature search mode, also known as an attentional bias, towards an arbitrary stimulus in healthy participants. Subjects were biased towards the colour green by an information sheet. Attentional bias was assessed using a change detection task. After an interval of either 1 or 2 weeks, participants were then retested on the same change detection task, tested on a different change detection task where colour was irrelevant, or were biased towards an alternative colour. One experiment included trials in which the distractor stimuli (but never the target stimuli) were green. The key finding was that green stimuli in the second task attracted attention, despite this impairing task performance. Furthermore, inducing a second attentional bias did not override the initial bias toward green objects. The attentional bias also persisted for at least two weeks. It is argued that this persistent attentional bias is mediated by a chronic change to participants’ attentional control settings, which is aided by long-term representations involving contextual cueing. We speculate that similar changes to attentional control settings and continuous cueing may relate to attentional biases observed in psychopathologies. Targeting these biases may be a productive approach to treatment.     

Speed discrimination in 6- and 10-month-old infants follows Weber's law

The speed of a moving object is a critical variable that factors into actions such as crossing a street and catching a ball. However, it is not clear when the ability to discriminate between different speeds develops. Here, we investigated speed discrimination in 6- and 10-month-old infants using a habituation paradigm showing infants events of a ball rolling at different speeds. The 6-month-olds looked longer at novel speeds that differed by a 1:2 ratio than at the familiar ones but showed no difference in looking time to speeds that differed by a 2:3 ratio. In contrast, the 10-month-olds succeeded at discriminating a 2:3 ratio. For both age groups, discrimination was modulated by the ratio between novel and familiar speeds, suggesting that speed discrimination is subject to Weber's law. These findings show striking parallels to previous results in infants' discrimination of duration, size, and number and suggest a shared system for processing different magnitudes.