What cognitive abilities are involved in trail-making performance?

Abstract

The cognitive abilities involved in the Connections (Salthouse, et al., 2000) version of the trail making test were investigated by administering the test, along with a battery of cognitive tests and tests of complex span and updating conceptualizations of working memory, to a sample of over 3,600 adults. The results indicate that this variant of the trail making test largely reflects individual differences in speed and fluid cognitive abilities, with the relative contributions of the two abilities varying according to particular measure of performance considered (e.g., difference, ratio, residual). Relations of age on trail making performance were also examined. Although strong age differences were evident in the Connections and working memory measures, with both sets of variables there was nearly complete overlap of the age differences with individual differences in speed and fluid cognitive abilities.

Figure 1

Illustration of the structural equation model used to investigate the relations of reference cognitive abilities (predictors) on simple and alternating versions of trail making performance. Circles correspond to latent constructs representing the variance common to several observed (manifest) variables, which are portrayed as squares. Single-headed arrows represent directed (regression) relations, and double-headed arrows represent correlations. Arrows with numbers adjacent to them had their coefficients were fixed to 1, and arrows without a source represent variances. The cognitive variables used to define the latent predictor constructs are not portrayed in the figure, but are described in the appendix, with the factor loadings presented in Table 2.

Figure 2

Illustration of the sequence of displays in the Symmetry Span and Operation Span tasks used to assess working memory with complex span procedures.

Figure 3

Illustration of the sequence of displays in the two running memory tasks used to assess working memory with updating procedures.

Figure 4

Mean number of items correct when connecting elements in numerical, alphabetic, and alternating numeric and alphabetic order starting with either numbers or letters as a function of age decades. Bars around the means are standard errors. Sample sizes in each decade ranged from 220 to 830.

Figure 5

Mean z-scores as a function of age decade on four reference cognitive abilities in the complete sample. Bars around the means are standard errors. Sample sizes in each decade ranged from 220 to 830.

Figure 6

Mean z-scores as a function of age decade for storage and processing measures from the complex span tasks. Bars around the means are standard errors. Sample sizes in each decade ranged from 25 to 165.

Figure 7

Mean z-scores as a function of age decade for the running memory measures from the updating tasks. Bars around the means are standard errors. Sample sizes in each decade ranged from 23 to 114.