Early and Late Selection in Young and Old Adults: An Event‐Related Potential Study

Abstract

The present experiment investigated differences in processing between young and old adults in a combined visual selection‐memory search paradigm. No evidence was found for age‐related differences in early visual selective attention. The elderly achieved relatively fast reaction times in the memory search task at the cost of a high error percentage. From these findings, and from the morphology of the event‐related potential, it was concluded that old subjects perform controlled memory search more superficially than young subjects, In both old and young subjects high memory load was associated with decreased positivity in the P3 and Slow Wave area. This is interpreted in terms of Okita et al.'s(1985) concept of search negativity. N2 amplitude was found to be larger to non‐target trials for both attended and unattended inputs. The latter result is discussed in relation to theories about N2 as an indicator of automatic mismatch detection.

Age-related decline in differentiated neural responses to rare target versus frequent standard stimuli

“…As individuals grow older, there appears to be a decrease in the specificity of activation of neural modules in response to different kinds of stimuli, such as target vs. non-target letters or numbers, images of faces vs. non-faces, and cued vs. non-cued locations (Curran, Hills, Patterson, & Strauss, 2001; Hahn, Wild-Wall, & Falkenstein, 2011; Kenemans, Smulders, & Kok, 1995; Looren de Jong, Kok, & van Rooy, 1988; Lorenzo-Lopez, Amenedo, Pazo-Alvarez, & Cadaveira, 2007; Park et al, 2012). This age-related loss of neural specialization has been indexed by comparing neural responses to different stimulus types and by measuring changes in the distribution of neural activity recruited to carry out task demands (Cabeza, Anderson, Locantore, & McIntosh, 2002; Lorenzo-Lopez et al, 2007).…”

“…First, many ERP studies that have examined age-related dedifferentiation, including our own, compared responses to the same class of stimuli under attend vs. ignore conditions (Alperin et al, 2013; Hahn et al, 2011; Lorenzo-Lopez et al, 2007), but have not investigated responses to different classes of stimuli under an attend condition only. Second, almost all prior reports have limited their investigation to young adults in their 20s and young-old adults in their 60s and 70s (Alperin et al, 2013; Cabeza et al, 2002; Curran et al, 2001; Hahn et al, 2011; Looren de Jong et al, 1988; Lorenzo-Lopez et al, 2007; Vallesi, Stuss, McIntosh, & Picton, 2009), leaving open questions about when in the lifespan dedifferentiation begins and whether it continues to progress in oldold age. Third, most prior studies have not explicitly tried to match different age groups in terms of cognitive capacity or performance on the experimental task (Curran et al, 2001; Hahn et al, 2011; Looren de Jong et al, 1988), making it problematic to interpret whether differences in neural activity between groups were due to age or other factors such as executive capacity, perceived task difficulty, or task performance.…”

“…Second, almost all prior reports have limited their investigation to young adults in their 20s and young-old adults in their 60s and 70s (Alperin et al, 2013; Cabeza et al, 2002; Curran et al, 2001; Hahn et al, 2011; Looren de Jong et al, 1988; Lorenzo-Lopez et al, 2007; Vallesi, Stuss, McIntosh, & Picton, 2009), leaving open questions about when in the lifespan dedifferentiation begins and whether it continues to progress in oldold age. Third, most prior studies have not explicitly tried to match different age groups in terms of cognitive capacity or performance on the experimental task (Curran et al, 2001; Hahn et al, 2011; Looren de Jong et al, 1988), making it problematic to interpret whether differences in neural activity between groups were due to age or other factors such as executive capacity, perceived task difficulty, or task performance. Fourth, most previous studies have included tasks with only one level of difficulty (Curran et al, 2001; Hahn et al, 2011; Looren de Jong et al, 1988; Lorenzo-Lopez et al, 2007), which does not provide the opportunity to address the issue of whether an age-related reduction in differentiated neural responses is a function of task demand.…”

“…Third, most prior studies have not explicitly tried to match different age groups in terms of cognitive capacity or performance on the experimental task (Curran et al, 2001; Hahn et al, 2011; Looren de Jong et al, 1988), making it problematic to interpret whether differences in neural activity between groups were due to age or other factors such as executive capacity, perceived task difficulty, or task performance. Fourth, most previous studies have included tasks with only one level of difficulty (Curran et al, 2001; Hahn et al, 2011; Looren de Jong et al, 1988; Lorenzo-Lopez et al, 2007), which does not provide the opportunity to address the issue of whether an age-related reduction in differentiated neural responses is a function of task demand.…”

The Dissociation between Early and Late Selection in Older Adults

“…Early selection involves the initial separation (i.e., early filtering) of stimuli in accordance with fundamental physical characteristics, such as location, orientation, or color (Broadbent, 1970; Kenemans, Smulders, & Kok, 1995; Looren de Jong, Kok, & van Rooy, 1988; Naatanen, 1992; Wijers, Mulder, Okita, Mulder, & Scheffers, 1989). Late selection involves categorizing a stimulus as a member of the target set based on additional processing of physical, functional, or semantic properties (i.e., decision-making) (Looren de Jong et al, 1988). In the current study, ERPs were used to investigate whether age-related changes in the allocation of resources to task-irrelevant stimuli were uniform across information processing stages or disproportionately affected either early or late selection.…”