Development of manipulatory skills and the deployment of attention

Two independent tasks, object manipulation and auditory-visual matching, were used to examine the relationship between developing manual action skills and attention to intermodal object properties in 3.5- and 5.5-month-olds. Although handling skills improved with age, with older infants demonstrating more varied manipulation, there were no age differences for the matching task. When grouped by handling skills, a significant interaction between skill and event type was found for the two age groups combined and for 5.5-month-olds alone. Auditory-visual matching of social events did not vary with handling skills, whereas auditory-visualmatching of object events did. Infants at higher skill levels responded similarly to social and object events, whereas less skilled infants' matching preferences were weaker for object events. These findings indicate that infants increase their attention to auditory and visual properties of objects as this information becomes useful for guiding new actions. This effect is independent of age due to considerable individual variability in the development of object handling skills.     

Young children's storage behavior in a memory-for-location task

Two experiments concerned with children's intentional preparation for future retrieval in a memory-for-location task are presented. In the first experiment, 3-, 5-, 7-, and 9-year-olds were instructed to store and subsequently retrieve an object on a large spatial display. All age groups, except the 3-year-olds, tended to store the object at distinctive locations and their retrieval performance was facilitated accordingly. The four age groups did not differ in the types of selections made in a nonmemory control task. The second experiment dealt with the effects of feedback and informational factors on strategy acquisition. Preschoolers were given experience at retrieving the object from distinctive and nondistinctive positions on the stimulus display. Later, when instructed to store the object by themselves, older preschoolers produced the distinctive-position storage strategy following a feedback procedure in which they directly observed the consequences of their retrieval selections. The strategy was adopted by younger preschoolers, but only when additional strategy and task information accompanied visual feedback. The use of external memory tasks with young children and factors affecting strategy acquisition and utilization are discussed.     

Reliance on visual and verbal information across ontological kinds: What do children know about animals and machines?

In two experiments, we systematically examined the reliance on visual (external shape and features) and verbal (origins and internal structure) information in isolation, and together in the identification of animals and machines by 3-, 4-, and 5-year-olds, and adults. Experiment 1 examined the use of visual and verbal information independently in a visual classification task, a verbal classification task, and an induction task. Experiment 2 examined the relative weighting of visual and verbal information in an induction task and a categorization task. The three most important findings from Experiment 1 were that (a) children and adults can use either visual or verbal information to distinguish animals from machines; (b) all age groups classified items with mixed visual information as machines, a tendency that increased with age; and (c) with age, children became increasingly able to induce non-obvious properties, especially the non-obvious properties of machines. The findings from Experiment 2 indicate that the youngest and oldest participants relied on both visual and verbal information in the identification of animals and machines in categorization and induction tasks. Five-year-olds, however, relied only on visual information. As in Experiment 1, we observed a tendency to judge items with contrasting information as machines, suggesting that individuals utilize a more strict definition (both visually and verbally) for the category of animals. We discuss the implication of these results with respect to developmental differences in the use of perceptual and conceptual information across the ontological distinction between artifacts and natural kinds.     

Recognition memory for complex visual discriminations is influenced by stimulus interference in rodents with perirhinal cortex damage

Rats with perirhinal cortex (PRC), hippocampal, or sham lesions were trained on a successive discrimination go/no-go task to examine recognition memory for an array of visual objects with varying interference among the objects in the array. Rats were trained to recognize a target array consisting of four particular objects that could be presented in any one of four possible configurations to cover baited food wells. If the four target objects were presented, the rat should displace each object to receive food. However, if a novel object replaced any one or more of the target objects, then the rat should withhold its response. The number of novel objects presented on nonrewarded trials varied from one to four. The fewer the number of novel objects in the array, the more interference the array shared with the target array, therefore increasing task difficulty. An increased number of novel objects should result in less interference with the target array and decreased task difficulty. Although accuracy was slightly lower in rats with hippocampal lesions compared with controls, the learning of the groups was not statistically different. In contrast, rats with PRC lesions were significantly impaired in learning compared with both control and hippocampal-lesioned rats. The results suggest that recognition memory for complex visual discriminations is affected by stimulus interference in rodents with PRC damage.     

Emergence of drawing devices for total and partial occlusion: a longitudinal study

The developmental emergence of two drawing devices was investigated in young children: the use of omission (ie not drawing any of a hidden object) to depict total occlusion and the use of hidden line elimination (HLE, ie deleting only that part of an object that is hidden from view) to depict partial occlusion in a three-dimensional scene. Three groups of school children (5, 6, and 7 years old) were tested individually with two tasks four times over a 2-year period. One task called for the omission device (to draw a cup with its handle not in view) and the other for the HLE device (to draw one ball behind and partially occluded by another). The stimuli in each task were presented in pairs, with one member of the pair showing the occluded scene and the other a canonical or not-occluded scene. Changes in the strategies used by the children to indicate the visual differences within the pairs were recorded over the four testing sessions. Children were found to use the omission device more readily with the cup task than the HLE device with the ball task. There was an age-related trend in every task in the use of the drawing device appropriate to that task. For those who did not use the drawing device appropriate for a perspective drawing, there was a tendency for each age group to favour a particular strategy for representation. The advantage of using a longitudinal design to chart the developmental trend of the emergence of these two drawing devices is discussed.     

Haptic object matching by blind and sighted adults and children

The present study describes a tactual object matching task based on the study of Lederman and Klatzky (1987) for the dimensions Exact shape, Weight, Volume and Texture. Participants were congenitally blind children and their sighted classmates, congenitally blind adults and sighted adults. To study a possible effect of familiarity the task was performed four times. Based on Millar's CAPIN (Convergent Active Processes in Interrelated Networks) model of spatial processing (Millar, 1994) it was thought that this manipulation would add redundant information to the experiment from which the children and blind participants could benefit. The results showed that accuracy was affected more by age than visual status, especially for the dimension Exact Shape. With regard to response times, children were in most cases faster than adults, especially the sighted adults. Familiarization had a significant effect on response times for all dimensions. Extra exercise only increased accuracy for the dimension Texture. These results were generally in line with the CAPIN model.     

Evoked potentials in reaction time with a variable foreperiod

The reaction times (RTs) of 12 subjects were recorded in a design where a visual or auditory warning signal preceded an auditory RT signal by one of four short foreperiods 500, 750, 1000 or 1250 ms long, which occured in a random sequence. For the 16 trials at each foreperiod, with each modality of warning signal, the average of the 2-s long EEG samples following the warning signal was computed so that the record showed the scalp recorded (vertex--left mastoid) evoked potentials (EPs) to both warning and RT signals, and also the contingent negative variation or expectancy wave occurring during the foreperiod.

Differences between RTs with different foreperiods were not reflected in negatively correlated differences in the amplitude of the RT signal EPs, taking the major positive going deflection between peaks N1 and P2 at mean latencies of 126 and 231 msec after the RT signal. Furthermore RT signal EPs preceded by a warning signal were highly attenuated in amplitude relative to control EPs which were not preceded by a warning signal, whether or not an RT response was required. This was despite the fact that alerted RTs were slightly faster than non-alerted RTs, so that these findings contradict previous findings associating augmented EPs with responding versus not responding and with speeded RTs.

However, it was also found that RT signal EP amplitudes were greater with the more effective modality of warning signal than the less effective, which was consistent with previous findings. The divergence from previous findings when comparing EPs preceded by a warning with those having no prior warning is tentatively accounted for in terms of persisting physiological refractoriness following the warning signal EP.     

The effect of smoking on sensory and attentional masking

This study examined the influence of smoking on low-level sensory and higher level visual cognitive abilities. Three groups (nonsmokers, deprived smokers, and nondeprived smokers) of 22 observers were tested using a visual target discrimination task. To assess sensory and visual cognitive differences, a masking task developed by Enns and Di Lollo (1997) was used. In the task, the target was masked by either a contour mask (contour masking) or an object mask (attentional masking by object substitution). The strongest masking effects were found in the group of nondeprived smokers, for both sensory and attentional masking. This pattern of results as well as results in the deprived smokers indicated changes in transient visual processing channels due to the acute actions of nicotine, not mediated by withdrawal relief.     

Socio‐economic Status (SES) Affects Infants' Selective Exploration

Infants change their behaviours in accordance with the objects they are exploring. They also tailor their exploratory actions to the physical context. This selectivity of exploratory actions represents a foundational cognitive skill that underlies higher‐level cognitive processes. The present study compared the development of selective exploratory behaviours in high and low socio‐economic status (SES) infants. Sixty‐one 6–8‐ and 10–12‐month‐old infants were presented with rigid and flexible cubes on a tray that was half rigid and half flexible. There were SES effects for each category of exploratory behaviours: object only, surface only and object–surface interactions. Low‐SES infants engaged in comparable amounts of exploratory behaviours with high‐SES infants, but they exhibited behaviours less conducive to information uptake, compared with high‐SES infants. The results suggest difficulty for low‐SES infants in transitioning to more mature exploration strategies. Copyright © 2015 John Wiley & Sons, Ltd.     

Infants' use of material properties to guide their actions with differently weighted objects

Two studies with 9‐, 11‐ and 13‐month‐old infants were conducted to investigate infants' ability to use an object's material properties to guide their object‐directed actions. In study 1, 9‐ and 11‐month‐old infants played in an exploration phase with two objects made of different materials, one very heavy and the other one light and playable. Subsequently, when given the choice between both objects in a preferential reaching task, only the 11‐month‐olds' used the object's material information to remember and choose the lighter object. In study 2, 11‐ and 13‐month‐old infants underwent the same exploration phase. In the test phase, novel objects made of the same materials were offered. The 13‐ but not the 11‐month‐olds chose the objects made from the same material as the lighter object in the exploration phase. Additionally, infants' performances in the reaching task were positively correlated with their exploratory behaviour during the exploration phase. Altogether, the studies show a developmental progression in the use of an object's material information to guide infants' action. The results are discussed in respect to infants' perception of object properties and their implications for the development of physical knowledge. Copyright © 2010 John Wiley & Sons, Ltd.     

A study of reaching actions in walking infants

Acquiring motor skills transforms the perceptual and cognitive world of infants and expands their exploratory engagement with objects. This study investigated how reaching is integrated with walking among infant walkers (n = 23, 14.5–15.5 months). In a walk-to-reach paradigm, diverse object retrieval strategies were observed. All infants were willing to use their upper and lower bodies in concert, and the timing of this coordination reflected features of their environment. Infants with an older walking age (months since walking onset) retrieved items more rapidly and exploited their non-reaching hand more effectively during object retrieval than did same-age infants with a younger walking age. This suggests that the actions of the upper- and lower-body are flexibly integrated and that this integration may change across development. Mechanisms that shape sophisticated upper-body use during upright object retrieval are discussed. Infants flexibly integrate emerging motor skills in the service of object retrieval in ways not previously documented.     

Behavioral and neural analyses of connotative meaning: Word classes and rating scales

Behavioral (semantic differential) and neural (Evoked Potentials, EPs) responses were related to connotative meaning. The approach was based on Osgood's semantic analyses and dimensions of Evaluation (E), Potency (P), and Activity (A). The experimental variables were (1) the semantic class of the stimulus word (E+, E-, P+, P-, A+, A-) and (2) the dimension of the semantic scale (E, P, A) which the subject used to rate the stimulus words. These variables were experimentally combined such that on each trial the subject used a designated semantic scale to judge a specified stimulus word while brain activity was recorded. Using multivariate analyses, the effects on the EPs of stimulus word class, scale dimension, and their interaction were analyzed. The EP effects of stimulus word class were similar whether the subjects were merely saying the words or rating the words on a variety of semantic scales. Different EPs were found for six word classes, three semantic scale dimensions, and the 18 groups formed by their combination. The success rates in EP identification of (1) word class and (2) scale dimension did not depend on whether these two kinds of semantic variables involved the same or different semantic dimensions. The two kinds of semantic effects in EPs were largely independent. The behavioral data supported Osgood's results and showed that our subjects were appropriately processing the semantic information. The common analyses of data from all subjects suggest the universality of the connotative EP effects across individuals. This parallels, at the neural level, the universality of the connotative dimensions found at the behavioral level by semantic differential ratings. The EP effects imply that the neural representation of meaning is similar in different individuals.     

From interpretation to segmentation

In visual perception, part segmentation of an object is considered to be guided by image-based properties, such as occurrences of deep concavities in the outer contour. However, object-based properties can also provide information regarding segmentation. In this study, outer contours and interpretations of object configurations were manipulated to examine differences between image-based and object-based segmentation in a visual search task. We found that locating a two-dimensional object configuration with deep concavities in the outer contour depends on the type of outer contour of the surrounding distractors. In addition, locating a three-dimensional object configuration was harder when it was surrounded by object-based-disconnected distractors, as compared with object-based-connected distractors, regardless of image-based connections in these distractors. We conclude that segmentation based on the outer contours of a target facilitates its localization. However, when three-dimensional information is available, segmentation strongly depends on object-based properties, rather than on image-based properties.     

Évolution des procédures d’exploration haptique chez des sujets voyants,aveugles tardifs et aveugles précoces

The aim of this research is to study the evolution of exploratory haptic procedures with different subjects (blindfolded, early and late blind subjects). Can a haptic training facilitate an emergence of particular and specific processes? A recognition task of bidimensional geometrical figures is proposed before and after a haptic training. Results show that when the criterion of differentiation of geometrical figures is discovered, subjects look for more details and compare more often figures between them. Otherwise, while sighted subjects use all exploratory procedures, blind subjects adopt preferably more metric procedures. However, a training effect is observed in sighted subjects with a decrease of less relevant procedures. Applications of this research could be developed in haptic therapy by proposing different training according to visual status.     

Processing of compound visual stimuli by children with autism and Asperger syndrome

A typical modes of visual processing are common in individuals with autism. In particular, and unlike typically developing children, children with autism tend to process the parts of a complex object as a priority, rather than attending to the object as a whole. This bias for local processing is likely to be due to difficulties in assembling subparts into a coherent whole, as proposed by Frith ( 10 1989) using the term “weak central coherence” or WCC. This study was aimed to better characterize the processing of complex visual stimuli by children with autism. Thirteen children with autistic spectrum disorders were individually paired with children of two control groups, one matched on verbal mental age (VMA) and one matched on chronological age (CA). Participants from the three groups were tested in two tasks. The first task involved hierarchical global/local stimuli, inspired by Navon ( 30 1977). The second task employed compound face‐like or geometrical stimuli. This task emphasized the processing of configural properties of the stimuli (i.e., spatial relationships). Children from the three groups showed a perceptual bias favouring the global dimension of the stimuli in the first task. By contrast, children with autism were deficient compared to normal children for the processing of the configural dimensions of the stimuli in the second task. These results suggest that visual cognition of children with autism is characterized by a dissociation between global and configural processing, with global processing being preserved and configural processing being altered in these children, therefore delineating the extents and limits of the WCC theory (Frith, 10 1989).     

Exploratory behavior and developmental skill acquisition in infants with Down syndrome

Infants learn about objects by exploring them. Typically developing infants actively explore objects through visual, manual, and oral modalities. Attenuated exploratory behavior has been observed in various neurodevelopmental disorders, including Down syndrome (DS), presumably limiting learning options. However, a direct link between exploration and overall developmental functioning has not been characterized. This study used a Latent Profile Analysis framework to examine within-syndrome variability in exploratory behavior in infants with DS and the developmental correlates of different exploratory behavior profiles. Participants were 45 infants with DS (CA = 9.58 months; SD = 3.62) who completed an object exploration activity and the Bayley Scales of Infant Development-III (BSID-III; Bayley, 2006). Exploration behavior was coded for the percentage of time engaged in visual, manual, and oral exploration. Results indicated that a 2-profile solution provided the best model fit for exploratory behavior, yielding profiles that represented either an Active (57.78% of the sample) or a Passive Exploratory (42.22% of the sample) profile. The Active Exploratory profile was associated with significantly higher age equivalent scores on the BSID-III Cognitive, Communication, and Motor domains than the Passive Exploratory profile. Other factors, such as sex and biomedical risk factors, were not associated with exploratory profiles. These findings offer a more nuanced understanding of early within-syndrome heterogeneity in DS, and demonstrate that impoverished early exploratory behavior may serve as an important indicator of increased risk for more pronounced developmental delays in DS.     

A psychophysical measure of visual and kinaesthetic spatial discriminative abilities of adults and children

Quantitative estimates of the spatial discriminative capacities of the visual and kinaesthetic systems in adults and children were obtained. Intersensory integration was investigated by including spatial discriminations based on congruent visual plus kinaesthetic reafference. The psychophysical method of adjustment was used with simultaneous comparisons of a fixed and a variable stimulus. The subject's task was to estimate when the variable stimulus (ellipse) was identical to the standard one (circle), under one of three modality conditions: vision, kinaesthesis, and vision plus kinaesthesis. After a pilot study with adults, children (aged 8, 10, and 12 years) and adults were both tested. Subjects from each age group were randomly allocated to each of the three experimental conditions. Results show that the visual and kinaesthetic estimates of the 8- and 10-year-old subjects did not differ significantly, but the visual responses of the adults and 12 year olds were significantly more accurate than corresponding kinaesthetic estimates. Bisensory estimates were significantly more accurate than visual responses only for the 8- and 10-year-old age groups. Intramodal comparisons showed the kinaesthetic estimates of the 8, 10, and 12 year olds to be significantly more accurate than the corresponding adult performance. Adult visual estimates were significantly more accurate than those made by 8 year olds, but were not significantly different from the visual responses of 10 and 12 year olds. Estimates based on bisensory reafference did not differ from each other across the four age groups. It is concluded that modality adeptness and dominance are task dependent and empirically determined rather than being innate properties of sensory systems. The data indicate that intersensory differentiation rather than integration occurs with maturity.     

Manual exploration of objects is related to 7-month-old infants’ visual preference for real objects

The present study examined whether infants’ visual preferences for real objects and pictures are related to their manual object exploration skills. Fifty-nine 7-month-old infants were tested in a preferential looking task with a real object and its pictorial counterpart. All of the infants also participated in a manual object exploration task, in which they freely explored five toy blocks. Results revealed a significant positive relationship between infants’ haptic scan levels in the manual object exploration task and their gaze behavior in the preferential looking task: The higher infants’ haptic scan levels, the longer they looked at real objects compared to pictures. Our findings suggest that the specific exploratory action of haptically scanning an object is associated with infants’ visual preference for real objects over pictures.     

Lateralization of the Approach Movement and the Prehension Movement in Infants from 4 to 7 Months

The aim of the study was to analyse lateralized preferences during reaching and grasping in infants relative to changes in manual actions from 4 to 7 months of age. Reaching and grasping movements with visual fixation were studied with objects placed in one of three places on a table: to the left, to the right and in the midline of the infant. Although the two lateralized objects were approached and grasped with ipsilateral hand, movements towards the object in the midline were most often performed with a preferential hand. There was preferential use of the left hand for reaching around the fourth month, then a preferential use of the right hand for grasping from the sixth month. The shape of the left hand during reaching movements terminated in the vicinity of the object. The slower the speed, the closer the hand came to the object. The onset of the prehension was associated with a preferential use of the right hand, which performed grasping, more finely than the left hand. Thus, manual specialization is already present in early infancy: the left hand appears to be dedicated to spatial calibration and the right hand to the task of prehension.     

Object and spatial imagery: distinctions between members of different professions

In the current research, we took a new approach to examining individual differences in mental imagery that relied on a key distinction regarding visual imagery, namely the distinction between object and spatial imagery, and further examined the ecological validity of this distinction. Object imagers consistently prefer to construct colorful, pictorial, high-resolution images of individual objects and scenes, and spatial imagers prefer to use imagery to schematically represent spatial relations among objects and can efficiently perform complex spatial transformations. To examine the ecological validity of the object versus spatial imager distinction, we examined the object and spatial imagery preferences and skills of groups of professionals.Visual artists, scientists, architects, and humanities professionals completed two types of imagery tests: spatial imagery tests assessing abilities to process spatial relations and perform spatial transformations, and object imagery tests assessing abilities to process literal appearances of objects in terms of color, shape, and brightness. A clear distinction was found between scientists and visual artists: Visual artists showed above average object imagery abilities but below average spatial imagery abilities; whereas, scientists showed above average spatial imagery abilities but below average object imagery abilities. Visual artists tended to be object imagers, and scientists tended to be spatial imagers. Thus, even though both groups use visual imagery extensively in their work, they in fact tended to excel in only one type of imagery.Furthermore, we interviewed the groups of professionals about imagery characteristics and imagery processes that they typically use when work, we had them interpret kinematics graphs and abstract art, and we monitored their eye-movements as they engaged in various perception and imagery tasks. The data revealed various qualitative differences between the professional groups. Both visual artists and scientists reported using imagery in their work. However, visual artists preferred to use object imagery, but scientists preferred to use spatial imagery for their work. Humanities professionals, however, reported less use of imagery. Additionally, visual artists reported that their images were more likely to come as a whole, but scientists reported that their images were generated part-by-part. Visual artist’s images were more persistent, less intentional, and had multiple meanings as compared to scientist’s images. Furthermore, visual artists and scientists interpreted kinematics graphs and abstract art qualitatively differently. Visual artists tended to interpret graphs literally (graphs-as-pictures), but scientists tended to interpret graphs schematically, in abstract way. However, visual artists tended to interpret the abstract art as abstract representations, but scientists tended to interpret abstract art literally, in a concrete way.The finding that professional domain, where work involves extensive use of object or spatial imagery, differentially predicted object and spatial imagery abilities and approaches in processing visual information provides ecological validation of the distinction between object and spatial imagers. Furthermore, these results provide support for the idea of a trade-off between object and spatial imagery abilities (i.e., a person being more effective at using one type of imagery and then tending to use this type of imagery more frequently than and at the expense of the other type of imagery).