Visuospatial attention-networks are represented in both hemispheres, with right-hemisphere dominance in adults. Little is known about the lateralization of the attentional-networks in children. To assess the lateralization of attentional-networks in children aged 5 years, performance on a Lateralized-Attention-Network-Test specifically designed for children (LANT-C) was compared with performance on the Attention-Network-Test for children (ANT-C). Participants were 82 children, aged 5–6 years (55% boys, middle–class, mainstream schooling). They were examined with both the ANT-C and the LANT-C along with evaluation of intelligence and attention questionnaires. Multiple analysis of variance showed a main effect for network, with high efficiency for orienting and lower executive efficiency (accuracy; p < .001; η2 = .282). An effect for procedure, elucidated higher efficiency in the ANT-C relatively to the LANT-C (accuracy; p < .01; η2 = .097). A procedure × network interaction effect was also found, showing that this procedure difference is present in the alerting and executive networks (accuracy; p < .05; η2 = .096). LANT-C analysis showed a left visual-field advantage in alerting, (accuracy; p < .05; η2 = .066), while executing with the right hand benefitted executive performance (response-time; p < .05; η2 = .06). Results extend previous findings manifesting a right-hemisphere advantage in children's alerting-attention, pointing to the importance of lateralization of brain function to the understanding of the integrity of attention-networks in children. (JINS, 2014, 20, 1–10)

Neurologically normal individuals show a bias toward the left side of space, referred to as pseudoneglect due to its similarity to clinical hemispatial neglect. The left bias appears to be stronger in the lower visual field during free-viewing, which could result from preferential dorsal stream processing. The current experiments used modified greyscales tasks, incorporating motion and isoluminant color, to explore whether targeting dorsal or ventral stream processing influenced the strength of the left bias. It was expected that the left bias would be stronger on the motion task than on a task incorporating isoluminant color. In Study 1, similar left biases were observed during prolonged viewing for luminance, motion and red, but not green color. The unexpected finding of a leftward bias for red under prolonged viewing was replicated in Study 2. A leftward bias for motion was also evident during 150 ms viewing in Study 2. In Study 3, the left bias was not apparent when using a blue/yellow condition, suggesting the left bias for red under prolonged viewing was likely unique to red. Furthermore, the leftward bias for red disappeared under brief viewing conditions. It is suggested that dorsal stream processing likely underlies visual field differences in pseudoneglect. (JINS, 2012, 18, 251–259)

The reason people read from top to bottom is unknown, but could be related to brain-mediated directional biases or environmental factors. To learn if there is a brain-mediated directional bias responsible for top–down reading direction, we evaluated the directional scanning in the vertical dimension by using directional letter and face cancellation tasks. Twenty participants were instructed to cancel either target letters or faces using either an up–down or down–up direction, with the stimuli located in left, right, and center hemispace. The results indicated significant differences in completion time between the search direction (up vs. down) and spatial position for the letter cancellation task, with a faster completion time for the bottom–up scan in right space and top–down in left space. Because the left hemisphere primarily attends to contralateral right hemispace our results suggest that, when attending to letter stimuli, the left hemisphere is biased to scan in a proximal to distal (upward) direction. Although the reasons why this is reversed in left hemispace and why we did not see directional biases in the face condition remains unclear, these results do suggest that the direction in which we learn to read is inconsistent with the brain's intrinsic directional bias. (JINS, 2008, 14, 102–109.)

That the human frontal lobes are particularly vulnerable to age-related deterioration has been frequently invoked as an explanation of functional decline in aging. This “frontal aging hypothesis” is evaluated in this review by examining evidence of selectively reduced frontal lobe function in aging. The frontal aging hypothesis predicts that functions largely dependent on frontal regions would decline in aging, while functions largely independent of frontal lobes would remain relatively spared. The hypothesis further predicts that age-related brain change would selectively impact frontal regions. The literatures on working memory, visuospatial attention, face recognition, and implicit memory were reviewed as exemplars of functions dependent on prefrontal, parietal, temporal and occipitotemporal cortices, respectively, with a view to establishing mediating structures and effects of aging. Age sensitivity was seen both in functions dependent on frontal integrity as well as in functions apparently independent of frontal integrity. Further, although prefrontal areas exhibit age-related decreases in regional volume, blood flow and metabolism, nonfrontal cortical regions undergo similar declines. It is concluded that while the frontal lobes are subject to age-related changes reflected in both behavior and pathology, there is only weak and conflicting evidence that frontal regions are selectively and differentially affected by aging. It is argued that a network-based theory of cognitive aging has advantages over the localizationist approach inherent in the frontal aging hypothesis. (JINS, 2000, 6, 705–726.)