ABSTRACT
In 1983 Bryden, Munhal l , and A l l a r d published an often-cited article where they studied the intrusive effects o f attention on D L performance, and found that the ear advantage could be reliably modified by shifting attention to either ear. Bryden, Munhal l , and A l l a r d (1983) interpreted these findings as being, to a large extent, due to "biased attention," a source o f error that should be removed from the situation. Other studies have also found effects o f attention on D L performance (e.g., Hiscock & Kinsbourne, 1977; Hiscock & Stewart, 1984; Treisman & Geffen, 1968; see also Hiscock & Beckie, 1993). Several o f these studies were developmental in nature. For example, Sexton and Geffen (1979) showed that 7-year-old children could increase both their right-and left-ear scores by attending to either ear. Similarly, Hiscock and Beckie found that 7-and 10-year-olds were able to overcome the R E A when instructed to focus attention on the left-ear stimulus (see also Hiscock & Kinsbourne, 1980, who reported effects o f attention already in 3-4-year-old children). In contrast, other studies have reported "resistance" to attentional effects up to the age o f 9 years (e.g., Andersson & Hugdahl, 1987). St i l l other studies have found that even older children under certain circumstances may have problems modifying the ear advantage through attention (e.g., Obrzut & Bol iek , 1988). Kershner and Mor ton (1990), finally, reported that the ability to attend to either ear was dependent on the level o f reading abili ty-similar to the findings reported by Hugdahl and Andersson (1987). Thus, the issue o f attentional modulation o f a stimulus-driven laterality effect in D L is sti l l an unsettled issue, particularly from a developmental perspective.
