Elsevier

Brain and Cognition

Volume 63, Issue 3, April 2007, Pages 279-286
Brain and Cognition

Efficiency of route selection as a function of adult age

https://doi.org/10.1016/j.bandc.2006.09.006Get rights and content

Abstract

Two tasks hypothesized to assess the efficiency of route selection were administered to 328 adults ranging from 18 to 93 years of age. Increased age was associated with slower completion of mazes, even after adjusting for differences in perceptual-motor speed, and with longer and less accurate routes in a task in which participants were asked to visit designated exhibits in a zoo. The route selection measures were correlated with measures hypothesized to represent executive functioning, such as the number of categories in the Wisconsin card sorting test and the number of words generated in a category fluency test. However, most of the age-related influences on the measures from the route selection tasks were shared with age-related effects on established cognitive abilities, which implies that the same mechanisms may account for the relations of age on both sets of variables.

Introduction

Selecting routes is an interesting cognitive task because it requires decisions about how to achieve a specific goal (i.e., reach a destination) while satisfying various constraints (such as avoiding barriers, visiting intermediate locations, etc.). Route selection almost certainly involves aspects of planning, but it is likely to involve other cognitive abilities as well. Furthermore, tasks with these requirements have been hypothesized to be particularly sensitive to frontal lobe damage (e.g., Shallice and Burgess, 1991, Wilson et al., 1996). The two major goals of the research described in this report were to examine the influences of different cognitive abilities, including measures often used to assess executive functioning, on route selection measures, and to investigate the effects of aging on measures of route selection efficiency.

A number of studies have investigated age differences in learning or memory of routes, and have found that older adults tend to perform at lower levels than young adults on many measures (e.g., Caplan and Lipman, 1995, Lipman, 1991, Lipman and Caplan, 1992). Age differences favoring young adults have also been reported in learning to navigate through real (e.g., Barrash, 1994, Wilkniss et al., 1997), or virtual (e.g., Moffat and Resnick, 2002, Moffat et al., 2001), environments. Although the learning and memory of spatial information is interesting, the focus in the current study was on processes concerned with planning or selecting routes rather than learning or remembering them. That is, we were more interested in aspects of planning than in learning or memory.

Two measures were used to assess efficiency of route selection. One was the time to complete perceptual mazes, and the other was the distance of the route selected to visit six exhibits in a zoo. Several studies have compared adults of different ages in maze tasks (e.g., Davies, 1973, Heron and Chown, 1967, Newman and Kaszniak, 2000, Salthouse, 1995), and in most of them time to complete the maze was the primary outcome measure. However, simple solution time likely includes the time for perceptual-motor processes, visual search, etc. in addition to the time to select a route, and therefore it is desirable to attempt to minimize these other influences when studying efficiency of route selection.

The Mazes task in the current study consisted of two conditions in which the participants were asked either merely to trace a path through a maze, or to solve and trace the maze by planning and drawing a path through the maze. In both conditions the instructions were to complete the activity as quickly as possible. The additional time to solve, as opposed to trace, the maze can be postulated to reflect the duration of processes associated with route selection. People who are more efficient at selecting routes might therefore be expected to have a smaller difference between their solution time and their tracing time.

The second route selection task included in the study was an adaptation of a zoo trip task described in Wilson et al. (1996) and recently used by Allain et al. (2005). In our version of the task the participants were given a map of a zoo and were allowed as much time as desired to select the most efficient route to visit a specified set of exhibits. Shallice and Burgess (1991) speculated that this type of route selection or planning task is dependent on the frontal lobes, in contrast to the posterior and parietal involvement that has been found to be associated with the learning or remembering of routes (e.g., Meulenbroek, Petersson, Voermans, Weber, & Fernandez, 2004).

In addition to examining how measures of performance on these two route selection tasks were related to one another and to the age of the participant, we were also interested in the relations of performance on these tasks to other types of cognitive functioning. One other type of cognitive functioning is executive functioning, which might be expected to be related to route selection because it likely requires planning, which is often considered to be an aspect of executive functioning. All of the participants in the project also performed three tasks often assumed to assess executive functioning, namely, the Wisconsin card sorting test, and the letter fluency, and category fluency tests.

In addition to examining the relations among the route selection variables and other cognitive abilities, we were also interested in the relations of age on the measures of route selection. However, because adult age differences have been found in a wide variety of cognitive variables (e.g., Craik and Salthouse, 2000, Salthouse, 2004a, Salthouse, 2004b, Salthouse, 2005), it is important to determine the degree to which any age-related influences on the route selection variables are unique, and statistically independent of age-related influences on other variables. That is, no separate explanation of age-related effects on route selection may be needed if all of the age-related effects on the variables of interest are shared with effects on other variables. A reference battery of cognitive tests designed to assess four cognitive abilities was therefore also administered to the participants, and the age-related effects on the route selection variables were examined in the context of age-related effects on these abilities.

Two potentially informative sets of results can be obtained from these types of contextual analyses in which the age relations on the variables of interest are examined in the context of age-related influences on other cognitive variables (cf. Salthouse, 2005, Salthouse et al., 2006). One relevant result concerns the unique age relations on the target variable, which indicate age-related influences on the route selection variables that are statistically independent of influences on established cognitive abilities. Only if the unique age-related effect is significantly different from zero would a distinct explanation necessarily be required to account for age-related effects in measures of route selection. The second informative result from the contextual analyses concerns the influences of different cognitive abilities on the target variable, as manifested by relations between an individual’s level of a particular cognitive ability and his or her performance on the route selection task. Because the relative magnitudes of these relations indicate which cognitive abilities are important for successful performance in the task, this information is valuable in determining what the variables actually represent (cf. Salthouse, 2005).

Section snippets

Participants

The research participants were 328 individuals between 18 and 93 years of age recruited via flyers, newspaper advertisements, and referrals from other participants. Approximately 78% of the participants were Caucasian, 12% African-American, with the remaining individuals representing a variety, or mixture, of ethnicities. Two participants were excluded because their scores on a dementia screening instrument, the mini-mental status examination (Folstein, Folstein, & McHugh, 1975), were less than

Results1

Summary measures of performance for each task in the three age groups are presented in Table 2. It is apparent that both maze tracing time and maze solution time were greater with increased age. An analysis of variance was conducted on the maze completion times with age (three levels; age 18–39, 40–59, and 60–93) complexity (three levels; simple, medium, and complex) and condition (two levels; trace and solve) as factors. All main effects and interactions in this analysis were significant (F > 

Discussion

The results of this study suggest that there is a moderate age-related decline in measures of the efficiency of route selection (i.e., the solve—trace difference in the maze task, and efficiency of routes in the zoo trip task). The results in Table 2 suggest that the decline may accelerate after about age 60, but this trend needs to be interpreted cautiously because it could be at least partially attributable to a ceiling effect in the performance of younger adults.

The measures of performance

Acknowledgment

We thank the assistance of the following people in scheduling and testing participants and entering and checking data: Gauri Bhuchar, Kristina Caudle, Katherine Kane, Lacy Krueger, Josh Magee, Cristina Rabaglia, Jena Saporito, Julia Siegel, Shannan Smith, and Lauren Walker. This research was supported by NIA RO1AG19627 Grant to T.A.S.

References (25)

  • A.D. Davies

    Age and temperament effects on maze performance under speed and accuracy stress

    Perceptual and Motor Skills

    (1973)
  • S.E. Garden et al.

    Midlife aging, open-ended planning, and laboratory measures of executive function

    Neuropsychology

    (2001)
  • Cited by (31)

    • Helping older pedestrians navigate unknown environments through vibrotactile guidance instructions

      2018, Transportation Research Part F: Traffic Psychology and Behaviour
      Citation Excerpt :

      Whereas older people have no difficulty using and memorizing landmarks when they are navigating in simple virtual environments containing few details, they have proven unable to use landmark information efficiently and to select the most relevant cues when they are moving in complex environments (Moffat & Resnick, 2002). Route planning difficulties also increase with aging (Allain et al., 2005; Salthouse & Siedlecki, 2007). In a map-learning task, older people were shown to make more route errors when returning to their starting point and more long-distance estimation errors than younger people (Mahmood, Adamo, Briceno, & Moffat, 2009).

    • Review of safety and mobility issues among older pedestrians

      2016, Accident Analysis and Prevention
      Citation Excerpt :

      This decrease in processing speed has been shown to be associated with a slow walking speed and a higher risk of falling (Holtzer et al., 2007; Owsley and McGwin, 2004; Rosano et al., 2012; Welmerink et al., 2010). A slower processing speed may also partly explain poorer navigation performance with aging (Kliegel et al., 2007; Salthouse and Siedlecki, 2007). Finally, because processing speed is necessary for making timely, correct decisions, it could also explain the longer start-up times of older pedestrians, as well as the link observed between the safeness of street-crossing decisions made in simulator experiments and scores on the UFOV® test (Dommes and Cavallo, 2011; Dommes et al., 2013, 2015).

    • Reprint of 'Age-related changes in executive control and their relationships with activity performance in handwriting'

      2013, Human Movement Science
      Citation Excerpt :

      This task requires the ability to formulate and implement a plan independently and to follow a pre-formulated plan. Other studies have reported results similar to those of the present study related to this specific task, with more difficulties (Allain et al., 2005) and slower performance (Salthouse & Siedlecki, 2007) found among elderly adults in comparison to the younger groups. However, the interesting question is which BADS tasks significantly distinguish between groups which are not in the extreme age range.

    • What do we know about aging and spatial cognition? Reviews and perspectives

      2012, Ageing Research Reviews
      Citation Excerpt :

      They found that older adults made more spatial route memory errors (i.e., had a higher tendency to revisit incorrect locations) and traveled longer linear distances when solving the task. Salthouse and Siedlecki (2007) demonstrated that there was a moderate decline in the efficiency of route selection as age increased from 18 to 93 years, and comparable studies have reported similar findings (e.g., Allain et al., 2005; Lipman and Caplan, 1992). These reports suggest that the age-related declines in navigation may be due to deficits in the planning of the pathway rather than its execution.

    View all citing articles on Scopus
    View full text