Where's the ball? Two- and three-year-olds reason about unseen events.

Children 2, 2?, and 3 years of age engaged in a search task in which they opened 1 of 4 doors in an occluder to retrieve a ball that had been rolled behind the occluder. The correct door was determined by a partially visible wall placed behind the occluder that stopped the motion of the unseen ball. Only the oldest group of children was able to reliably choose the correct door. All children were able to retrieve a toy that had been hidden in the same apparatus if the toy was hidden from the front by opening a door. Analysis of the younger children's errors indicated that they did not search randomly but instead used a variety of strategies. The results are consistent with the Piagetian view that the ability to use representations to guide action develops slowly over the first years of life. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What do two-year-olds understand about hidden-object events?

Preferential-looking studies suggest that by 2 months of age, infants may have knowledge about some object properties, such as solidity. Manual search studies of toddlers examining these same concepts, however, have failed to provide evidence for the same understanding. Investigators have recently attempted to reconcile this disparity but failed to control for the visual novelty of test outcomes. The current design corrected this problem and also tested toddlers' predictions of the object's location. The task involved the same events and apparatus that have been used in manual search tasks but used looking as the dependent measure. Children looked longer when an agent opened the correct door and found no ball than when an incorrect door was opened to reveal no ball. A 2nd experiment indicated that children's preferential-looking performance did not differ from that in manual search tasks simply because additional response time had been allowed to respond. Previous comparisons of looking versus reaching tested children's postdiction response to an object in an unexpected location, but these findings indicate that toddlers can predict where the object should be. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

长筒球磨机简体结构改造

通过对包钢选矿厂Φ3.6 m×6.0 m的长筒球磨机筒体,进行了受扭矩和重力作用的分析,并进行简支梁的扭矩和受力计算。结合实际运行情况,把筒体上原为两个人孔门结构,改造为一个人孔门结构。经过对人孔结构改造,减少了人孔门处裂漏所矿导致的很多故障,创造了可观的经济效益。     

Infants interpret ambiguous requests for absent objects.

The current studies investigated 2 skills involved in 14- to 20- month-olds' ability to interpret ambiguous requests for absent objects: tracking others' experiences (Study 1) and representing links between speakers and object features across present and absent reference episodes (Study 2). In the basic task, 2 experimenters played separately with a different ball. The balls were placed in opaque containers. One experimenter asked infants to retrieve her ball using an ambiguous request ("Where's the ball?"). In Study 1, infants used the experimenter's prior verbal and physical contact with the ball to interpret the request. A control condition demonstrated that infants were interpreting the request and not responding to the mere presence of the experimenter. Study 2 revealed that only infants who were given stable cues to the ball's spatial location appropriately interpreted the request: When spatial information was put in conflict with a color cue, infants did not select the correct ball. Links to infants' spatial memory skills and emerging pragmatic understanding are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A core knowledge architecture of visual working memory.

[Correction Notice: An erratum for this article was reported in Vol 37(3) of Journal of Experimental Psychology: Human Perception and Performance (see record 2011-10888-001). The supplemental materials DOI is incorrect. The correct DOI for the supplemental materials is provided in the erratum.] Visual working memory (VWM) is widely thought to contain specialized buffers for retaining spatial and object information: a 'spatial-object architecture.' However, studies of adults, infants, and nonhuman animals show that visual cognition builds on core knowledge systems that retain more specialized representations: (1) spatiotemporal representations for object tracking, (2) object identity representations for object recognition, and (3) view-dependent snapshots for place recognition. In principle, these core knowledge systems may retain information separately from one another. Consistent with this hypothesis, this study provides evidence that these three types of information are subject to independent working memory storage limits. These results, combined with those from previous studies, indicate that VWM contains three specialized buffers for retaining spatiotemporal information, object identity information, and snapshot information. Thus, VWM buffers parallel core knowledge systems. This 'core knowledge architecture' links the study of visual working memory to the study of the biological foundations of visual cognition. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The spontaneous interconnection of four repertoires of behavior in a pigeon (Columba livia).

A pigeon was trained (a) to peck a small facsimile of a banana placed within its reach, (b) to climb onto a box, (c) to open a door, and (d) to push a box toward targets. When confronted with a new situation—the banana was placed out of reach, and the box was placed behind the door—the four repertoires came together rapidly to produce a humanlike solution to the problem. A tentative account of the performance is offered in terms of empirically validated principles. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"A core knowledge architecture of visual working memory": Correction to Wood (2011).

Reports an error in "A core knowledge architecture of visual working memory" by Justin N. Wood (Journal of Experimental Psychology: Human Perception and Performance, 2011[Apr], Vol 37[2], 357-381). The supplemental materials DOI is incorrect. The correct DOI for the supplemental materials is provided in the erratum. (The following abstract of the original article appeared in record 2011-06411-002.) Visual working memory (VWM) is widely thought to contain specialized buffers for retaining spatial and object information: a 'spatial-object architecture.' However, studies of adults, infants, and nonhuman animals show that visual cognition builds on core knowledge systems that retain more specialized representations: (1) spatiotemporal representations for object tracking, (2) object identity representations for object recognition, and (3) view-dependent snapshots for place recognition. In principle, these core knowledge systems may retain information separately from one another. Consistent with this hypothesis, this study provides evidence that these three types of information are subject to independent working memory storage limits. These results, combined with those from previous studies, indicate that VWM contains three specialized buffers for retaining spatiotemporal information, object identity information, and snapshot information. Thus, VWM buffers parallel core knowledge systems. This 'core knowledge architecture' links the study of visual working memory to the study of the biological foundations of visual cognition. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Is there an age-related positivity effect in visual attention? A comparison of two methodologies.

Research suggests a positivity effect in older adults' memory for emotional material, but the evidence from the attentional domain is mixed. The present study combined 2 methodologies for studying preferences in visual attention, eye tracking, and dot-probe, as younger and older adults viewed synthetic emotional faces. Eye tracking most consistently revealed a positivity effect in older adults' attention, so that older adults showed preferential looking toward happy faces and away from sad faces. Dot-probe results were less robust, but in the same direction. Methodological and theoretical implications for the study of socioemotional aging are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Observational learning of a left-right behavioral asymmetry in mice (Mus musculus).

B6D2F? hybrid mice that were allowed to observe a trained female mouse open a pendulum door to the right (or to the left) to enter a food compartment later solved this problem faster than pupils that had been placed behind a visual barrier. Male pupils that had observed a "left-handed" teacher performed sinistrally; males that had observed a "right-handed" model performed dextrally. Female pupils did not exhibit their demonstrator's laterality. Observational learning may provide a means to maintain certain lateralized behaviors. Such social learning may lead to the emergence of local traditions and to the cultural diffusion of behavioral asymmetries. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in the relationship between visual movement imagery and performance on kinesthetic acuity tests.

The Vividness of Movement Imagery Questionnaire was administered to 280 fourteen-year-olds and 186 ten-year-olds, who were then tested on measures of kinesthetic acuity. The relationship between visual movement imagery and kinesthetic acuity scores was significant in the older group: Those with high levels of visual movement imagery performed significantly better on measures of kinesthetic acuity than did those with low imagery. No such effect was found in the younger group. The results indicate that for adolescents, the confounding effect of visual imagery affects the researcher's ability to interpret kinesthetic acuity scores. The relationship between imagery and kinesthesis appears to develop over the period between 10 and 14 years, although such an interpretation may be premature because the measurement of visual movement imagery in the younger age group is problematic. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual tracking and entrainment to an environmental rhythm.

This study investigated the role that visual tracking plays in coupling rhythmic limb movements to an environmental rhythm. Two experiments were conducted in which participants swung a hand-held pendulum while tracking an oscillating stimulus or while keeping their eyes fixed on a stationary location directly above an oscillating stimulus. It was expected that the participants' rhythmic movements would become entrained to the oscillating stimulus in both conditions but that visual tracking would strengthen this entrainment. Experiment 1 investigated the role of visual tracking in establishing unintentional entrainment. Experiment 2 investigated the role of visual tracking in intentional entrainment. As predicted, participants exhibited greater unintentional coordination and more stable intentional coordination when they tracked the stimulus. These findings highlight the importance of understanding the role of eye movements in environmental coordination. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Binding and strategic selection in working memory: A lifespan dissociation.

Working memory (WM) shows a gradual increase during childhood, followed by accelerating decline from adulthood to old age. To examine these lifespan differences more closely, we asked 34 children (10–12 years), 40 younger adults (20–25 years), and 39 older adults (70–75 years) to perform a color change detection task. Load levels and encoding durations were varied for displays including targets only (Experiment 1) or targets plus distracters (Experiment 2, investigating a subsample of Experiment 1). WM performance was lower in older adults and children than in younger adults. Longer presentation times were associated with better performance in all age groups, presumably reflecting increasing effects of strategic selection mechanisms on WM performance. Children outperformed older adults when encoding times were short, and distracter effects were larger in children and older adults than in younger adults. We conclude that strategic selection in WM develops more slowly during childhood than basic binding operations, presumably reflecting the delay in maturation of frontal versus medio-temporal brain networks. In old age, both sets of mechanisms decline, reflecting senescent change in both networks. We discuss similarities to episodic memory development and address open questions for future research. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Aging and goal-directed emotional attention: Distraction reverses emotional biases.

Previous findings reveal that older adults favor positive over negative stimuli in both memory and attention (for a review, see Mather & Carstensen, 2005). This study used eye tracking to investigate the role of cognitive control in older adults' selective visual attention. Younger and older adults viewed emotional-neutral and emotional-emotional pairs of faces and pictures while their gaze patterns were recorded under full or divided attention conditions. Replicating previous eye-tracking findings, older adults allocated less of their visual attention to negative stimuli in negative-neutral stimulus pairings in the full attention condition than younger adults did. However, as predicted by a cognitive-control-based account of the positivity effect in older adults' information processing tendencies (Mather & Knight, 2005), older adults' tendency to avoid negative stimuli was reversed in the divided attention condition. Compared with younger adults, older adults' limited attentional resources were more likely to be drawn to negative stimuli when they were distracted. These findings indicate that emotional goals can have unintended consequences when cognitive control mechanisms are not fully available. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual factors in hitting and catching

To hit or catch an approaching ball, it is necessary to move a bat or hand to the right place at the right time. The performance of top sports players is remarkable: positional errors of less than 5 cm and temporal errors of less than 2 or 3 ms are reliably maintained. There are three schools of thought about how this is achieved. One holds that predictive visual information about where the ball will be at some future instance (when) is used to achieve the hit or catch. The second holds that the bat or hand is moved to the correct position by exploiting some relation between visual information and the required movement. The third focuses on the use of prior knowledge to supplement inadequate visual information. For a rigid spherical ball travelling at constant speed along or close to the line of sight, the retinal images contain both binocular and monocular correlates of the ball's instantaneous direction of motion in depth. Also, the retinal images contain both binocular and monocular information about time of arrival. Humans can unconfound and use this visual information, but they are unable to estimate the absolute distance of the ball or its approach speed other than crudely. In cricket, this visual inadequacy allows a slow bowler to cause the batsman to misjudge where the ball will hit the ground. Such a bowler uses a three-pronged strategy: first, to deliver the ball in such a way as to prevent the batsman from obtaining the necessary visual information until it is too late to react; secondly, to force the batsman to rely entirely on inadequate retinal image information; thirdly, to allow the batsman to learn a particular relationship between the early part of the ball's flight and the point where the ball hits the ground, and then to change the relationship with such skill that the batsman does not detect the change.     

What comes first? How selective attentional processes regulate the activation of a motor routine in a manual search task.

An intriguing error has been observed in toddlers presented with a 3-location search task involving invisible displacements of an object, namely, the C-not-B task. In 3 experiments, the authors investigated the dynamics of the attentional focus process that is suspected to be involved in this task. In Experiment 1, 2.5-year-old children were tested on a new adaptation of the C-not-B task in which the opening of the experimenter's hand between cloths provided visual information about the correct localization of the toy. Children still emitted a strong response bias toward the last hiding place. In Experiment 2, 2.5-year-old children were tested on a new version of the task that was designed to investigate the role of the central location in the task. This 2nd experiment demonstrated that changing the hand's movement from A to C to B did not enable children to succeed in the task. In Experiment 3, 2.5-year-old children were tested in a situation that is analogous to the C-not-B with open hands task except for the fact that the experimenter dropped the toy under the 1st cloth in the path. Toddlers succeeded when the toy was hidden at Location A but not when it was hidden at Location B. Data indicate that attentional focus on the experimenter's hand motion is contingent on whether that stimulus is critical to performing the task. We argue that these findings provide a potential mechanism through which motor routines can be regulated in accordance with strategic intentions. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Achieving Partnering Success through an Incentive Agreement: Lessons Learned from an Underground Railway Extension Project in Hong Kong

Over the years, it has been observed that partnering has been ineffectively implemented in the public sector of Hong Kong. Contributing factors to this lack of success are nature and the large size of bureaucratic organizations and commercial pressure compromising the partnering attitude. The Mass Transit Railway Corporation Limited (MTRCL), one of the prominent pioneers in adopting project partnering in the infrastructure sector of Hong Kong since 1999, however, implemented the partnering principle with significant success. This paper, based on a recently completed research project funded by the Construction Industry Institute?Hong Kong in late 2004 and a followup in-depth interview meeting with senior executives of MTRCL in early June 2005, analyzes the rationale behind the successful development of partnering culture in the infrastructure sector of Hong Kong through a case study—the Tseung Kwan O Railway Extension (TKE) Contract 654—platform screen doors. The project comprises the supply and installation of platform screen doors along the whole MTRCL’s TKE with five stations. This project was analyzed by means of the project documentation and face-to-face interviews with the project representatives, comparisons with another five partnering case studies, and a followup in-depth interview meeting with another two senior executives of MTRCL. After the analysis, it was found that the implementation of partnering together with an incentive agreement (IA), a kind of target cost (TC) contract, underpinned the partnering success of this project. Therefore, it is recommended that partnering together with TC contracts, such as IA, greatly assists in the achievement of construction excellence, and can provide a workable model for enhancing overall project performance in electrical and mechanical projects.     

The role of visual working memory in attentive tracking of unique objects.

When tracking moving objects in space humans usually attend to the objects’ spatial locations and update this information over time. To what extent do surface features assist attentive tracking? In this study we asked participants to track identical or uniquely colored objects. Tracking was enhanced when objects were unique in color. The benefit was greater when the distance between distractors and targets was smaller, but was eliminated when the objects changed colors 1 to 4 times per second, even though at any instant they were always uniquely colored. In addition, tracking uniquely colored objects impaired a secondary color-memory task more than tracking identical objects, and holding several colors in working memory eliminated the advantage of tracking uniquely colored objects. Contrary to previous studies showing that feature information is poorly retained during tracking, these findings indicate that surface properties are stored in visual working memory to facilitate tracking performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-term follow-up of patients with Crohn's disease treated with azathioprine or 6-mercaptopurine

BACKGROUND: Crohn's ulcerative gastrointestinal disease is presently managed through a variety of medical interventions, including-according to severity of illness-anti-inflammatory, immunosuppressive, and corticosteroid agents; and with remedial surgery to correct anatomical abnormalities caused by disease processes. The immunosuppressant azathioprine (or its metabolite, 6-mercaptopurine) is considered an efficient maintenance therapy for Crohn's, but there is always concern about bone-marrow suppression, liver damage, and other adverse effects. For how long persons with this disease should be given these drugs has not been determined. METHODS: Patients who were treated with azathioprine or 6-mercaptopurine for more than 6 months, and who were in prolonged clinical remission (> 6 months without steroids) were followed. The time-to-relapse was analysed in those on treatment, in those who stopped treatment for reasons other than a relapse, and in the whole sample, taking into account that they could be treated with the drugs or not, as a function of time. The influence of concomitant variables on time-to-relapse rate was examined using the Cox proportional hazard model. FINDINGS: In the 157 patients who continued to take the therapy, cumulative probabilities of relapse at 1 and 5 years were 11% and 32% respectively. Female gender, younger age, and a time for achieving remission more than 6 months were associated with a higher risk of relapse. In 42 patients who stopped therapy, probabilities of relapse at 1 and 5 years were 38% and 75%, respectively. Male gender, younger age and duration of remission less than 4 years were associated with a higher risk of relapse. After 4 years of remission on these drugs, the risk of relapse appeared to be similar, whether the therapy was maintained or stopped. INTERPRETATION: Taking into account the potential risks of long-term immunosuppressive therapy, the usefulness of maintaining azathioprine or 6-mercaptopurine in patients who have been in remission for more than 4 years is questionable.     

Superior visual search in autism.

Children with a diagnosis of autism and normally developing children, matched for age and general ability, were tested on a series of visual search tasks in 2 separate experiments. The children with autism performed better than the normally developing children on difficult visual search tasks,. This result occurred regardless of whether the target was uniquely defined by a single feature or a conjunction of features, as long as ceiling effects did not mask the difference. Superior visual search performance in autism can be seen as analogous to other reports of enhanced unique item detection in autism. Unique item detection in autism is discussed in the light of mechanisms proposed to be involved in normal visual search performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Object permanence in 3?- and 4?-month-old infants.

These experiments tested object permanence in 3-12- and 4-12-month-old infants. The method used in the experiments was similar to that used by Baillargeon, Spelke, and Wasserman (1985). The infants were habituated to a solid screen that rotated back and forth through a 180° arc, in the manner of a drawbridge. Following habituation, a box was placed behind the screen and the infants were shown two test events. In one (possible event), the screen rotated until it reached the occluded box; in the other (impossible event), the screen rotated through a full 180° arc, as though the box were no longer behind it. The 4-12-month-olds, and the 3-12-month-olds who were fast habituators, looked reliably longer at the impossible than at the possible event, suggesting that they understood that (a) the box continued to exist after it was occluded by the screen and (b) the screen could not rotate through the space occupied by the occluded box. Control experiments conducted without the box supported this interpretation. The results of these experiments call into serious question Piaget's (1954) claims about the age at which object permanence emerges and about the processes responsible for its emergence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)