Visual selective attention was investigated in children aged 5, 7 and 9 and in adults. The groups were compared on a filtering task in which conditions varied with regard to number (0, 2, 8) and location (close, far) of the non-relevant stimuli surrounding the targeted stimuli and the presence or absence of a solid-line border around the target stimuli. The results were analyzed with regard to development differences between the age groups. Contrary to expectations, the presence of non-relevant stimuli was not related to impaired performance nor was the presence of a solid-line border related to enhanced performance. No effect of border was found in any of the groups. However, the reaction times of older children and adults were faster with 8 non-relevant stimuli far from the target. Five year old children did not show this effect. This indicates that older children and adults can utilize this group of non-relevant stimuli as a tool to focus the attentional lens.

Because children are bombarded by an abundance of information from the environment, the development of the ability to filter extraneous information in order to attend to the most relevant information is crucial for optimal information processing. The ability to effectively filter affects every aspect of children's functioning, including educational activities and social interactions. In order to assess the development of filtering with ecologically relevant factors, a forced-choice filtering paradigm in which the target and distracting stimuli were presented at different times was used to measure the speed of target identification among a group of 6-year-olds (n=10), 7-year-olds (n=12), 9-year-olds (n=13) and adults (n=13). The targets were presented at the centre of a computer screen with flankers presented to their left and right along the same horizontal plane. The flankers varied with regard to proximity to the target and were presented 200 ms or 400 ms before, at the same time as, or 200 or 400 ms after the presentation of the target. The distance between the distractors and target was also varied to assess the ability of participants to optimally narrow their focus of attention. Temporal differences in the onset of the target and distractors were used to assess issues of attentional control in a real-world context, where attention must be maintained within a changing environment. Though no difference in response time was observed for the presentation of close and far flankers, the display of flankers before the targets led to faster response times in all four groups while the display of flankers after the target led to slower response times in the two youngest groups. The results are consistent with the notion that children are less efficient in their ability to filter attention compared to adults. Findings are discussed in relation to developmental changes from age 6 years to adulthood.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2002. / Includes bibliographical references (leaves 42-47).

Thesis (Ed. D.)--University of North Texas, Dec., 2009. / Title from title page display. Includes bibliographical references.

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The development of reflexive and voluntary shifts of visual attention, as well as relations between the two forms of shifting was examined in three groups of children (5-, 7-, and 9-years-old), one group of young adults (24-years-old), and two groups of senior adults (young seniors: 69-years-old, old seniors: 81-years-old). The task entailed the detection and response to the presentation of a target (black dot) in one of four possible locations in the visual field. The dependent measure was reaction time (RT). The extent to which flash cues facilitated or inhibited reflexive orienting was determined through presentation of nonpredictive abrupt onset peripheral flash cues prior to the target. Arrow facilitation and inhibition was measured by shifts of attention initiated in response to predictive central arrow cues. Relations between reflexive and voluntary shifts of attention were gauged by the degree to which flash and arrow facilitation and inhibition were observed in response to the presentation of both arrow and flash cues together in one trial. Conditions varied with regard to the validity of the location cues (accurate or inaccurate information regarding the location of the subsequent target) and the length of the interval between the cue and the target (SOA: 185 or 875 ms). All age groups demonstrated flash facilitation with the flash cue alone, demonstrating similar patterns of reflexive orienting across the lifespan. However, the three groups of children demonstrated the largest flash cue effects suggesting that they had the most difficulty ignoring the nonpredictive flash cues. With the arrow cue alone, young adults, and young and old senior adults were more efficient (faster RTs) in their execution of voluntary shifts, however, all age groups utilized the arrow cues to orient attention strategically and in doing so experienced similar patterns of arrow facilitation. When both flash and arrow cues were presented together, the 9-year-old children, young

The purpose of this study was to compare two conflicting theoretical perspectives on the relationship between intelligence and sustained attention. The cognitive resources theory assumes that lower IQ subjects are required to allocate greater amounts of their limited attentional resources during information-processing tasks than higher IQ subjects. The arousal theory assumes that there is an optimal level of arousal associated with task performance, and that an increase or decrease in arousal produces impairment in performance. Additionally the arousal theory predicts that increased time on task leads to a decrement in arousal as a function of IQ levels. Signal detection theory applications were used to operationalize and compare the two theories. Specifically, the signal detection parameters of sensory acuity ( d’), the decision criterion (a), correct detections, and false alarms were used to determine subject performance across three time periods ( 2, 4, and 6 mm.) on a visual continuous performance task. Twenty-nine teacher-nominated at-risk for learning difficulties and twenty-nine normally achieving kindergarten students were adminstered the Stanford-Binet:Fourth Edition (SB:FE) and the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI.R), as well as the Gordon Diagnostic System (GDS) Vigilance Task. The GDS is a standardized behaviour-based measure of sustained attention. The results of this study were interpreted as suggesting that ability group differences reflect attentional capacity. Two findings were important in this interpretation. First, regardless of IQ, the groups varied on the signal detection discrimination index. Second, these measures did not vary over time in either group. Thus, the arousal theory was not supported. IQ and attention intercorrelation patterns were higher for the at-risk group compared to the normally achieving group. Exploratory maximum-likelihood factor analyses indicated that intelligence plays a greater role in relation to vigilance for the at-risk for learning difficulties group than the normal achieving group.

Attentional orienting involves two neuroanatomically and functionally separate components, the reflexive and voluntary attentional sub-systems, which interact to orient attention on the environment. Three experiments, in which a cueing paradigm was used, examined reflexive and voluntary orienting over later childhood development (i.e., 8--14 years old) in order to explore the mechanisms underlying the development of the control of attentional orienting. Experiments 1 and 2 explored whether reflexive and voluntary orienting develop in parallel, and examined the influence of cue predictability on attentional orienting during development. Experiment 3 explored the role of explicit instructions in the influence of cue predictability on voluntary and reflexive orienting. The results indicate that the development of attentional orienting over later childhood is a reflection of the operation of an underlying mechanism, general developmental changes in speed of processing. Apart from this mechanism, the efficiency of attentional orienting remains the same across age. In addition, the influence of cue predictability on attentional orienting reflects the operation of a low-level mechanism which operates independently of strategic influences; this mechanism may be covariance detection and judgment. The implications of these conclusions for modeling attentional orienting, and the development thereof, are considered.