In terms of visual/spatial working memory, AU youth generally engaged less task-relevant areas. While study authors interpreted this as reflecting a lack of ability to access the expected neural regions, it is equally possible that this pattern of decreased activation accompanied by equivalent performance could reflect greater cognitive efficiency. A second consideration for interpretation is that AU youth engaged more task-irrelevant areas (e.g., temporal and/or dorsal regions which identify “where?” rather than “what?”) (Caldwell et al., 2005; Squeglia et al., 2011; Tapert et al., 2004b). However, several studies also indicated the use of more task-relevant regions within the AU group, particularly across the frontal (gyri), parietal (IPL, SPL), temporal (gyri) and precuneus (Caldwell et al., 2005; Squeglia et al., 2012a; Tapert et al., 2004b). The study authors interpreted this as AU youths' need to utilize more task-relevant resources (higher levels of activity in those areas) to achieve the same behavioural performance as non-AU youth. However, these interpretations are speculative, as it is not truly possible to know what reduced or heightened BOLD signal reflects in terms of level of engagement or related behaviour (see Limitations).
