Session 5: Attention across the lifespan

This week's articles address sustained attention and mind wandering over the lifespan. Richards (2008)* discussed the use of heart rate and eye movement measurements to study the development of sustained attention in infants. The eye movement studies showed that infants' general arousal systems develop along with their voluntary control of eye movements, that arousal both increases voluntary eye movement and is associated with voluntary shifts in the type of eye movement appropriate to tracking stimuli moving at different speeds in infants about 20 weeks and older, and that top-down control over eye movements may increase between 4 months and 2 years of age (Richards, 2008). Lin, Hsiao, and Chen (1999)** studied development of sustained attention in school-age children using versions of the Continuous Performance Test (CPT), which requires participants to respond to rare target stimuli interspersed among non-target stimuli presented at a rapid fixed rate. They found that performance on the CPT improves—first rapidly and then more slowly—in children between ages 6 and 15 and particularly between ages 6 and 12, suggesting that the cognitive inhibition aspect of sustained attention develops during that period (Lin et al., 1999). Carriere et al. (2010)*** and Jackson and Balota (2011)**** studied decreases in reported mind wandering and observed errors on sustained attention tasks in older adults. Carriere et al. (2010) found that adults tend to respond more slowly and accurately on the sustained attention to response task (SART) as they age but that measures of actual task disengagement on the SART decreased only in early adulthood (age 20 to 30) and remained stable afterwards, suggesting that sustained attention ability does not change with aging but that older adults tend to use a more cautious response strategy. Jackson and Balota (2011), measuring reaction times and reported mind wandering, found that older adults are less likely to exhibit mind wandering than younger adults but were generally no slower or more accurate and showed just as much reaction time speeding immediately prior to a SART error as younger adults after correcting for general age-related slowing of mental processing. They did find that older adults were slower and more accurate on an “easier” version of the SART, though only the accuracy difference was significant, and they noted that older adults show more slowing after making an error on the SART, indicating that either reestablishing cognitive control after an error becomes more difficult with age or that older adults engage in more self-evaluative (and in this case, task-related) mind wandering (Jackson & Balota, 2011). Thus, taken together, these studies indicate that sustained attention capacity develops through childhood and early adolescence and remains stable with aging but that older adults mind wander off task less (though they might engage in more task-related mind wandering) and may develop different strategies for sustained attention tasks.

Studying differences in sustained attention across the lifespan raises certain experimental challenges. First, infants and very young children cannot be tested using standard measures like the SART. Thus, as Richards (2008) described, measures like heart rate and eye movements are often used to study attention in infants. Richards (2008) mentioned that some of the eye movement studies included children up to 7 years old, providing some basis for comparison with older children and adults who tend to be tested using more behavioral measures. But the techniques used for infants and for older children and adults appear not to overlap much. Similarly, Lin et al.'s (1999) study with school-age children used a different task than Carrier et al.'s (2010) and Jackson and Balota's (2011) studies with adults did. The tasks seem to measure the same sustained attention abilities, but comparing children's and adults' abilities would be more reasonable if they were tested on the same task or if the tasks were explicitly validated against each other.

Second, the Lin et al. (1999), Carrier et al. (2010), and Jackson and Balota (2011) studies were all cross-sectional, leaving the possibilities of demographic differences and generation effects among the age groups. These potential non-age differences are probably relatively small with school-age children within a relatively narrow age range recruited from the same schools as in the Lin et al. (1999) study. And Jackson and Balota (2011) explicitly examined differences in education, vocabulary, and personality to separate the effects of those variables from age effects in their study. But considering the large age ranges in the Carrier et al. (2010) and Jackson and Balota (2011) studies, the participants in different age groups might be non-equivalent in ways that the studies did not control for because of such factors as generational experience with computers and other technology and qualitative differences in education over time. Indeed, one reason why older adults tend to find the SART more engaging and more challenging than younger adults do (cf. Jackson & Balota, 2011) might be because the older adults in the participant pool were not exposed to computers early in life the way the younger adults were. Two ways to overcome potential generation effects might be to conduct a longitudinal study on the same participants as they age or to repeat the studies later as the populations from which the older participants are drawn begin to resemble the populations from which the younger participants are currently drawn and compare the results to those in the current studies. But either of those types of studies would not produce results for years into the future.

* Richards, J. E. (2008). Attention in young infants: A developmental psychophysiological perspective. Handbook of Developmental Cognitive Neuroscience. C.A. Nelson & M. Luciana. Cambridge, MA, MIT Press.

** Lin, C. C., Hsiao, C. K., & Chen, W. J. (1999). Development of sustained attention assessed using the Continuous Performance Test among children 6-15 years of age. Journal of Abnormal Child Psychology, 27, 403-412.

*** Carriere, J. S., Cheyne, J. A., Solman, G. J., & Smilek, D. (2010). Age trends for failures of sustained attention. Psychology and Aging, 25, 569-574.

**** Jackson, J. D. & Balota, D. A. (2011). Mind-wandering in younger and older adults: Converging evidence from the sustained attention to response task and reading for comprehension. Psychology and Aging, 27, 106-119.