The Test of Everyday Attention (TEA)

The following subtests were selected from the TEA (Robertson et al., 1994).

3.3.6.1Map Search

This is a test of visual selective attention in which participants are required to search for designated symbols of one type on a coloured map for a 2-minute period. The score is the number of symbols found within a 2-minute period (maximum possible score is 80), representing the efficiency with which stimuli can be filtered to detect the relevant information and reject or inhibit the irrelevant or distracting information (see Appendix 12).

3.3.6.2Telephone Search

This is a visual selective attention task in which participants must look for 4 types of designated key symbol pairs and ignore other symbols, while searching entries in a simulated classified telephone directory. The score is calculated by dividing the total time taken by the number of symbols detected. Lower values represent a superior performance or an efficient visual selective attention in detecting several types of targeted information while rejecting similar but irrelevant information. This task may also draw upon visual working memory holding the 4 types of target symbols in mind for comparison (see Appendix 13).

3.3.6.3Elevator Counting with Distraction

This task, in addition to involving auditory selective attention, also draws upon auditory-verbal working memory. Participants have to count the same pitched tones while ignoring the interspersed high pitch tones which have been introduced as distracters. The score indicates the number of strings counted correctly, giving scores ranging from 0 to 10, representing the efficacy in filtering off auditory distractions (see Appendix 14).

3.3.6.4Lottery

In this subtest, which is considered to be a measure of sustained attention, the

63

All numbers are in sets of three and are preceded by two letters. Participants are instructed to write down the two letters preceding all numbers that end in 55. These are considered ‘winning’ numbers. There are 10 ‘winning’ numbers

randomly included during the 10-minute presentation. The participants score is the number of correctly recorded numbers (maximum = 10). This subtest was found to have a significant relationship to a traditional sustained attention measure, PASAT, in the factor analysis of Bate and colleagues (2004) study. The former can be

considered as a purer measure of sustained attention as it does not require mathematical ability or working memory as does the PASAT.

3.3.6.5Telephone Search while Counting (Dual Task)

While this task loaded on the sustained attention factor in the factor analysis of Robertson and colleagues (1994) study, it is also considered a measure of divided attention (Chan et al., 2002). In this task, the subject must again search the telephone directory while simultaneously counting strings of tones presented by a tape recorder. This subtest yields a ‘dual task decrement’ score which is calculated by subtracting the time per target score of the previous subtest from the time per target score on the current subtest, which has been weighted for accuracy of tone counting. Lower and negative values represent a superior performance on this task. Essentially, by using the dual task decrement score, the previous Telephone Search subtest serves as the ‘motor control task’ for the dual task subtest, by which individual variation in processing speed or psychomotor speed has been controlled for as advocated by Verstraeten and Cluydts (2004) (see Appendix 16).

3.3.6.6Visual Elevator

This subtest is considered to be a measure of (visual) attentional switching. Participants are asked to count a series of drawings of elevator doors that are presented in rows on the pages of presentation booklet. The task is self-paced. The drawings of the elevator doors are interspersed with large up- and

down-pointing arrows, indicating that the direction of counting should change in line with the arrow (i.e., counting up or down). Two separate scores are derived from this subtest: the first score represents the number of visual strings counted correctly (maximum score = 10) inversely related to the mental errors elicited during

attentional switching, while the second score is a timing score calculated by dividing the total time taken for the correct items by the total number of switches for the correct items by the total number of switches for the correct items, indicating the

64

efficiency of attentional switching. Lower values represent a superior performance to higher values on this timing score (see Appendix 17).

In the factor analysis of Robertson and colleagues (1994) study, the Visual Elevator subtest was found to have a significant relationship with the WCST (Berg, 1948; Heaton, Chelune, Talley, Kay, & Curtiss, 1981, 1993; Nelson, 1976), originally developed as a test of ‘flexible thinking’ and now widely used as a measure of executive function. However, WCST is a somewhat complex measure in which the subject must work out a rule, use feedback and remember previous responses, in addition to switching from one strategy to another. Visual Elevator reduces the demands for all but the last of these capacities (Manly et al., 1999), hence can be considered as a purer measure of mental flexibility or set-shifting, one of the three key components of executive function (Miyake et al., 2000).

3.3.6.7Auditory Elevator with Reversal

This task is a measure of (auditory) attentional switching and is presented at a fixed speed on audio tape. Participants are required to count string of ‘medium’ pitched tones. Interspersed with these ‘medium’ pitched tones are both high and low tones (indicating the subject must switch to counting up or down respectively). The score represents the number of strings of tones counted correctly (maximum = 10) (see Appendix 18).

3.3.7Austin Maze (Milner, 1965; Tucker, Kinsella, Gawith, & Harrison, 1987;