The Attentional Blink (AB) is a measure of temporal visual attention (Raymond, Shapiro and Amell, 1992) and the primary concern of present thesis was how the duration of the AB varied over increasing age and stages of cortical development.
The involvement of the working memory and associated frontal cortical areas suggested that younger participants would yield poorer performance on this task than would adults. Results from investigations with frontal lobe patients (Richer and
Lepage, 1996) suggested a deeper and more protracted AB at early stages of frontal lobe development, before full connections with the cortex are established (Hashimoto et. al, 1995; Hudspeth, 1987 and Stuss, 1992). This thesis finds a progressively reduced AB in participants across the range of 7-years of age to adult and this is attributed to poorer working memory function in children - a claim that is supported by the results of subsequent working memory investigation. A broader picture of visual attentional development is provided in a second set of experiments demonstrating that, unlike temporal attention, spatial attention is adult like by the age of 7-years old. The visual search tasks employed also utilise working memory (Duncan and Humphreys, 1989), but of a different nature to the AB and operating in different cortical networks. This finding suggests that the varying functions of the frontal cortex develop at differing rates.
The final set of experiments demonstrates that the developmental differences seen in visual attention and executive function are not limited to the controlled setting of the laboratory. It is important to show ecological validity for these claims and this is achieved with the use of video games. Developmental improvement on two novel games requiring executive skill, suggests frontal development and this claim is reinforced by the illustration of a significant inverse relationship between video game playing score and total AB magnitude. This finding supports recent claims by Green and Bavelier (2003) that training on an action video game leads to faster recovery of temporal attention during an AB task.
Results presented within this thesis have significant implications for future research within the field of visual attention, specifically the advancement of knowledge regarding frontal executive functions and their development. The video game
investigation brings this research into the domain of socially relevant questions and modem technology and allows clinical and educational hypotheses to be drawn.