Developmental differences in cognitive scanning and encoding of visual information

Report accuracy of horizontally arranged letter sequences was measured for second-grade children and adults using a tachistoscopic single report procedure. Results indicated age differences in both the amount of information encoded out of visual sensory store and in the magnitude of left-right visual field differences. However, large age differences in amount of encoded information were also present under conditions which served to reduce left-right visual-field asymmetries in report accuracy. These findings are discussed in terms of their implications for using a left-to-right cognitive trace scanning explanation to account for age differences in encoding efficiency.     

A developmental study of the effect of familiarity on short-term visual memory

An attempt was made to specify whether previously reported limitations on young children's full-report capacity lay in a smaller amount of available information, in a shorter trace duration of information in visual information storage (VIS), or in poorer coding of information into permanent storage. Five- and 8-year-olds and adults were shown an eight-item array of figures. followed at varying intervals by an indicator signaling the subject to report the figure to which the indicator had pointed. The effects of three levels of familiarity or “labelability” were examined. While no age differences were revealed in amount of information available nor in the trace duration of information in VIS, strong age differences emerged in coding of information into permanent storage. Data on latency to verbal labeling and familiarity suggested that verbal labeling could not account for the age trends. Rather, the differences seemed to lie in the use of organized visual coding and rehearsal strategies by adults and their relative lack of use by children.     

Visual information processing in relation to age and to reading ability.

Temporal aspects of early visual information processing were studied developmentally in good and in poor reading male subjects ranging in age from 7 to 13 years. Forced-choice temporal integration and backward masking tasks, respectively, were utilized to assess duration of visual persistence and of relative rate of visual information processing. The results did not reveal differences in either visual persistence or processing rate in relation to reading ability at any age level studied. However, processing rate was found to increase markedly with chronological age in both the good and the poor readers while visual persistence did not vary significantly. The findings were discussed in relation to earlier work and in relation to current theoretical formulations of visual information processing.     

Visual skills and playing positions of Olympic field hockey players

Many sports require fine spatiotemporal resolution for optimal performance. Previous studies have compared anticipatory skills and the decision-making process in athletes; however, there is little information on visual skills of elite athletes, particularly hockey players. To assess visual skills of Olympic hockey players and analyze differences by playing position, and to analyze improvement of visual skills after training, 21 Olympic field hockey players were pre- and post-tested on 11 visual tasks following a 10-wk. visual training program consisting of computer-based visual exercises. There were no mean differences at pre-test between players of different positions, suggesting that performance on these visual skills was independent of playing position. However, after training, an improvement was seen in all players (when scores were averaged across all 11 visual tasks) with goalkeepers improving significantly more than any other position. This suggests the possibility of improving visual skills even in an elite population.     

Impact of language on development of auditory-visual speech perception

The McGurk effect paradigm was used to examine the developmental onset of inter-language differences between Japanese and English in auditory-visual speech perception. Participants were asked to identify syllables in audiovisual (with congruent or discrepant auditory and visual components), audio-only, and video-only presentations at various signal-to-noise levels. In Experiment 1 with two groups of adults, native speakers of Japanese and native speakers of English, the results on both percent visually influenced responses and reaction time supported previous reports of a weaker visual influence for Japanese participants. In Experiment 2, an additional three age groups (6, 8, and 11 years) in each language group were tested. The results showed that the degree of visual influence was low and equivalent for Japanese and English language 6-year-olds, and increased over age for English language participants, especially between 6 and 8 years, but remained the same for Japanese participants. This may be related to the fact that English language adults and older children processed visual speech information relatively faster than auditory information whereas no such inter-modal differences were found in the Japanese participants' reaction times.     

The effect of pre-movement delays on pointing accuracy in middle childhood.

In adults, the introduction of a pre-response delay has been shown to affect accuracy in pointing tasks while leaving accuracy in perceptual matching tasks unaffected. Here, we report on the effect of pre-movement delays on pointing accuracy in 6-10-year-old children. Children of this age group are of particular interest as their reliance on visual cues to monitor and correct their reaches appears to change during this period of development. Nineteen children were asked to point to the location of a target light after a delay of 0, 1, 2, or 4 s following target extinction. Performance was measured in two conditions: (i) open-loop, where the child reproduced the target locations in complete darkness, and (ii) with visual feedback, where information about hand position was available. Errors in the direction and in the amplitude of each reaching movement were recorded separately. The results show that temporal delay significantly affects the pointing movements of these children. Accuracy (mean) deteriorated after only 1 s whereas the precision (standard deviation) of the responses deteriorated after 4 s. Errors in amplitude, but not errors in direction, were reduced by the provision of visual feedback. Taken together, the findings suggest that amplitude and directional components of pointing in childhood utilise different sources of information, which differ in the extent to which temporal constraints operate.     

Development of Face Recognition in 5- to 15-Year-Olds

This study focuses on the development of face recognition in typically developing preschool- and school-aged children (aged 5 to 15 years old, n = 611, 336 girls). Social predictors include sex differences and own-sex bias. At younger ages, the development of face recognition was rapid and became more gradual as the age increased up until the age of 11, after which point the influence of age was insignificant. This development could not be sufficiently explained by the improvement in visual attention or design memory tasks. Girls were slightly better than boys at recognizing faces in the youngest age group, but the effect of sex was minor. No significant own-sex bias was found for girls or boys.     

Exploring the specificity of age-related differences in theory of mind tasks

Tasks assessing theory of mind (ToM) and non-mental state control tasks were administered to young and older adults to examine previous contradictory findings about age differences in mental state decoding. Age differences were found on a verbal ToM task after controlling for vocabulary levels. Older adults achieved significantly lower scores than did younger adults on static and dynamic visual ToM tasks, and a similar pattern was found on non-ToM control tasks. Rather than a specific ToM deficit, older adults exhibited a more general impairment in the ability to decode cues from verbal and visual information about people.     

Interindividual differences among native right-to-left readers and native left-to-right readers during free viewing task

Human visual exploration is not homogeneous but displays spatial biases. Specifically, early after the onset of a visual stimulus, the majority of eye movements target the left visual space. This horizontal asymmetry of image exploration is rather robust with respect to multiple image manipulations, yet can be dynamically modulated by preceding text primes. This characteristic points to an involvement of reading habits in the deployment of visual attention. Here, we report data of native right-to-left (RTL) readers with a larger variation and stronger modulation of horizontal spatial bias in comparison to native left-to-right (LTR) readers after preceding text primes. To investigate the influences of biological and cultural factors, we measure the correlation of the modulation of the horizontal spatial bias for native RTL readers and native LTR readers with multiple factors: age, gender, second language proficiency, and age at which the second language was acquired. The results demonstrate only weak or no correlations between the magnitude of the horizontal bias and the previously mentioned factors. We conclude that the spatial bias of viewing behaviour for native RTL readers is more variable than for native LTR readers, and this variance could not be demonstrated to be associated with interindividual differences. We speculate the role of strength of habit and/or the interindividual differences in the structural and functional brain regions as a cause of the RTL spatial bias among RTL native readers.     

Visual perseveration in normal and mentally retarded children

Visual perseveration was investigated within mentally retarded and second, fifth, and eighth grade normal children (Ns = 12 each group). Subjects matched an auditorially presented click to the onset and offset of visually presented stimuli. Time differences between visual stimulus offset and the point at which subjects reported simultaneity of the click and visual stimulus offset was assumed to reflect visual perseveration. Results showed: (a) no differences between the normal children as a function of age; (b) no difference between groups for stimuli of 100 msec. or longer duration; and (c) retarded subjects judged stimuli of 20 and 50 msec. to be of shorter duration than did normal subjects. This highly specific distinction between retarded and normal subjects suggests a difference in an early stage of perceptual processing.     

Development of visuo-haptic transfer for object recognition in typical preschool and school-aged children

Object recognition is a long and complex adaptive process and its full maturation requires combination of many different sensory experiences as well as cognitive abilities to manipulate previous experiences in order to develop new percepts and subsequently to learn from the environment. It is well recognized that the transfer of visual and haptic information facilitates object recognition in adults, but less is known about development of this ability. In this study, we explored the developmental course of object recognition capacity in children using unimodal visual information, unimodal haptic information, and visuo-haptic information transfer in children from 4 years to 10 years and 11 months of age. Participants were tested through a clinical protocol, involving visual exploration of black-and-white photographs of common objects, haptic exploration of real objects, and visuo-haptic transfer of these two types of information. Results show an age-dependent development of object recognition abilities for visual, haptic, and visuo-haptic modalities. A significant effect of time on development of unimodal and crossmodal recognition skills was found. Moreover, our data suggest that multisensory processes for common object recognition are active at 4 years of age. They facilitate recognition of common objects, and, although not fully mature, are significant in adaptive behavior from the first years of age. The study of typical development of visuo-haptic processes in childhood is a starting point for future studies regarding object recognition in impaired populations.     

Development of a vocabulary of object shapes in a child with a very-early-acquired visual agnosia: A unique case

We report a longitudinal study of an exceptional child (S.R.) whose early-acquired visual agnosia, following encephalitis at 8 weeks of age, did not prevent her from learning to construct an increasing vocabulary of visual object forms (drawn from different categories), albeit slowly. S.R. had problems perceiving subtle differences in shape; she was unable to segment local letters within global displays; and she would bring complex scenes close to her eyes: a symptom suggestive of an attempt to reduce visual crowding. Investigations revealed a robust ability to use the gestalt grouping factors of proximity and collinearity to detect fragmented forms in noisy backgrounds, compared with a very weak ability to segment fragmented forms on the basis of contrasts of shape. When contrasts in spatial grouping and shape were pitted against each other, shape made little contribution, consistent with problems in perceiving complex scenes, but when shape contrast was varied, and spatial grouping was held constant, S.R. showed the same hierarchy of difficulty as the controls, although her responses were slowed. This is the first report of a child's visual–perceptual development following very early neurological impairments to the visual cortex. Her ability to learn to perceive visual shape following damage at a rudimentary stage of perceptual development contrasts starkly with the loss of such ability in childhood cases of acquired visual agnosia that follow damage to the established perceptual system. Clearly, there is a critical period during which neurological damage to the highly active, early developing visual–perceptual system does not prevent but only impairs further learning.     

Age differences in peripheral letter perception

The capacities of 96 eight- and nine-year-old children and 96 adults to discriminate letters in the visual periphery were tested. Four-letter arrays were presented at the fixation point or centered 4 degrees to the left or right. Threshold exposure durations were estimated by a method of ascending limits. Analyses of a transformed threshold measure revealed that although children were less able than adults to discriminate letters in all positions, age differences were greatest for peripherally presented arrays. Development specific to the peripheral visual systems seems implicated.     

Reaction Time,Age, and Cognitive Ability: Longitudinal Findings from Age 16 to 63 Years in Representative Population Samples

Reaction time variables are used widely in studies of human cognitive ageing and in research on the information processing foundations of psychometric intelligence. The research is largely based on biased population samples. In the present study, large (500+), representative samples of the population of the West of Scotland were tested at ages 16, 36 and 56 years on simple and choice reaction time. Participants were re-tested eight years later, at which time they also took the Paced Auditory Serial Addition Test (PASAT). We report simple and choice reaction time means and their variabilities, their stability across 8 years, and their correlations with the PASAT. Simple and choice reaction times become slower and more variable with age. Women from age 36 to 63 show more variability in choice reaction times than men, an effect which remains after controlling for mean reaction time. Reaction time differences largely account for age differences, but not sex differences, in PASAT scores.     

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.     

The hare and the snail: Dissociating visual orienting from conscious perception

A method for investigating attentional effects of peripheral visual objects, independently of perceptual identification, is described. We report an experiment using this method which shows that visual processing of peripheral objects differs radically, depending on whether participants move attention in response to an object or consciously perceive that object. When luminance contrast was reduced, conscious perceptual discrimination of peripheral letters was massively slower and less accurate—but both low and high contrast letters elicited rapid attentional orienting effects and these rapid orienting effects were equal in magnitude across low and high contrast. This pattern is consistent with known differences in luminance sensitivity between the dorsal and ventral visual processing streams, and with rapid dorsal–ventral interaction mediated via re-entrant feedback. Our findings show that the control system responsible for rapid movements of attention is exquisitely sensitive to visual form information at low levels of contrast, and involves a different neurocognitive pathway to that which gives rise to conscious perception.     

Eye movements and picture processing during recognition

Eye movements were monitored during a recognition memory test of previously studied pictures of full-color scenes. The test scenes were identical to the originals, had an object deleted from them, or included a new object substituted for an original object. In contrast to a prior report (Parker, 1978), we found no evidence that object deletions or substitutions could be recognized on the basis of information acquired from the visual periphery. Deletions were difficult to recognize peripherally, and the eyes were not attracted to them. Overall, the amplitude of the average saccade to the critical object during the memory test was less than 4.5 degrees of visual angle in all conditions and averaged 4.1 degrees across conditions. We conclude that information about object presence and identity in a scene is limited to a relatively small region around the current fixation point.     

Aging and Visual Short-term Memory: Effects of Object Type and Information Load

ABSTRACT

Previous research has observed that the size of age differences in short-term memory (STM) depends on the type of material to be remembered, but has not identified the mechanism underlying this pattern. The current study focused on visual STM and examined the contribution of information load, as estimated by the rate of visual search, to STM for two types of stimuli – meaningful and abstract objects. Results demonstrated higher information load and lower STM for abstract objects. Age differences were greater for abstract than meaningful objects in visual search, but not in STM. Nevertheless, older adults demonstrated a decreased capacity in visual STM for meaningful objects. Furthermore, in support of Salthouse's processing speed theory, controlling for search rates eliminated all differences in STM related to object type and age. The overall pattern of findings suggests that STM for visual objects is dependent upon processing rate, regardless of age or object type.     

Adult age differences in the effects of sentence context and stimulus degradation during visual word recognition

I investigated adult age differences in the efficiency of feature-extraction processes during visual word recognition. Participants were 24 young adults (M age = 21.0 years) and 24 older adults (M age = 66.5 years). On each trial, subjects made a word/nonword discrimination (i.e., lexical decision) regarding a target letter-string that was presented as the final item of a sentence context. The target was presented either intact or degraded visually (by the presence of asterisks between adjacent letters). Age differences in lexical decisions speed were greater for degraded targets than for intact targets, suggesting an age-related slowing in the extraction of feature-level information. For degraded word targets, however, the amount of performance benefit provided by the sentence context was greater for older adults than for young adults. It thus appears that an age-related deficiency at an early stage of word recognition is accompanied by an increased contribution from semantic context.     

Roles of Visual Information for Control of Reaching Movements in Children

What visual information do children normally require for the control of reaching movements? How is performance affected when children do not have access to the preferred mode of perceptual information? These questions were studied in 28 children who were tested on 3 occasions: at 6, 7, and 8 years of age. The task was to pick beads, 1 at a time, from 1 cup and carry them to another cup. With the aid of a mirror arrangement and a curtain, the amount of visual information was manipulated with regard to both the target and the performing hand. The movements were monitored with an optoelectronic device (SELSPOT II) and analyzed in terms of transport and object-handling phases. Results showed that object handling required visual information on both hand and target. For the transport phase of the movement, visual information on the spatial location of the target was sufficient, and sight of the hand did not improve performance. In contrast to adult subjects, when children did not have access to the required visual information, their performances deteriorated markedly. These results indicate that from the age of 6, children use visual information for control of arm movements in a manner like that of adults, although with less accuracy and speed. However, even 8-year-old children are limited in their ability to use alternative perceptual strategies for movement control, and they therefore become less flexible and more dependent on visual information.