Abstract
It is well established that humans experience declines in visual cognition with age, including a slowing in the speed of cognitive processing and in shifts of visuospatial attention (Madden et al., 2005; Salthouse, 1996). The P3 ERP component is useful in understanding the relationship between cognitive decline and aging, as its latency and amplitude are thought to index the speed and efficiency of stimulus evaluation and attentional resource allocation, respectively. A plethora of studies have shown that P3 latency increases and amplitude decreases with age, reflecting a slowing of stimulus evaluation processes and a deficit in the amount of attentional resources allocated during this. In addition, the N2pc component, a correlate of the allocation of visuospatial attention, also has been shown to increase in latency and decrease in amplitude with age (Lorenzo-López et al., 2008), reflecting age-related slowing and reduction of attentional resource allocation. Here, we investigate the effectiveness of speed of processing (SOP) training in improving older adults' processing speed and attentional allocation in a visual search task, evidenced by changes in the P3b and N2pc components after training. SOP training is a cognitive intervention involving computerized attention and memory tasks, designed to enhance perceptual processing and processing speed of visual stimuli. Before and after 20 hours of SOP training, ERPs were recorded while older adults searched for a singleton feature target defined by an orientation difference to the distractors. Results indicate that SOP training increases the amplitudes of both the P3 and N2pc and decreases the latency of the P3 in response to a target pop-out. Results suggest that SOP training enhances both visual processing speed and the allocation of attention to relevant stimuli in older adults. Behavioral performance and ERP differences in relation to young adult participants and older controls (without training) will also be discussed.