They suggested this is because the integration Talazoparib of VgaAba might be ‘easier’ to achieve. As open-mouthed visual /ga/ is less predictive (Van Wassenhove et al., 2005) and therefore less in conflict with the auditory stimulus, the VgaAba condition is easier to combine into a fused percept. By contrast, the visual /ba/ in the VbaAga-combination is more predictive due to a specific lip movements, and may lead
to a perception of a cross-modal mismatch. Recent eye-tracking data corroborates this interpretation: 6-month-old infants discriminated between the VgaAba-fusion and the VbaAga-combination in terms of the duration of looking to the mouth (Tomalski et al., 2012). They looked for a significantly shorter time in the VbaAga-combination than in either the VgaAba-fusion or the canonical /ba/ and /ga/ conditions. The role of visual attention in AV integration remains
a matter of debate. One line of research suggests that high attentional load or a distracter moving across a speaking face (but not obscuring the mouth) could affect the quality of AV integration in adults (Tiippana Veliparib cell line et al., 2004; Alsius et al., 2005; Schwartz, 2010), while other studies indicate that even in the absence of directed attention to the mouth it is not possible to completely ignore mouth movements (Buchan & Munhall, 2011; Paré et al., 2003;). However, the processes that are almost automatic in adults may require more attention resources in infants. Of particular interest is the developmental shift in selective visual attention
to speaking faces during the first year of life: while younger infants attend predominantly to the eyes, this preference changes to increased looking to the mouth during the second half of the first year (Lewkowicz & Hansen-Tift, 2012; Tomalski et al., 2012; Wagner et al., 2013). By the age of 9 months looking to the mouth for VbaAga-combination increases significantly so that there is no longer any difference in looking times during presentation of these two types of incongruent stimuli, the combination and the fusion (Tomalski et al., 2012). In the present study, we asked whether the increased looking time to the mouth between 6 and 9 months of age indicates either: (i) an increased interest in AV mismatch or (ii) an enhanced use of visual speech cues in an attempt to integrate the Glutamate dehydrogenase auditory and visual information. In the first scenario, the amplitude of the AVMMR would be expected to increase due to enhanced processing of the mismatched information, while the opposite pattern could be expected if the AV cues are perceived to be integrated. We employed the same stimuli used in Kushnerenko et al. (2008) and Tomalski et al. (2012), that is, audiovisually matching and mismatching videos of female faces pronouncing /ba/ and /ga/ syllables; and used both electrophysiological (event-related potential; ERP) and eye-tracking (ET) techniques, with all infants assessed within one testing session.