Social Attention to Infants
Figure 2. Performance on probe detection task. Difference RTs for probes appearing behind adult faces minus probes appearing behind infant faces, as a function of stimuli and participant race. Note. Higher numbers indicate greater attentional allocation to infant over adult faces. Error bars represent 6 1S.E. doi:10.1371/journal.pone.0012509.g002
occupied by the infant face or the location previously occupied by the adult face.
Figure 1. Trial sequence for probe detection task (White infant–adult face pairing and South Asian infant–adult pairing). doi:10.1371/journal.pone.0012509.g001
infant faces of any race capture attention; in this case, both own- and other-race infant faces would be expected to capture attention. On the other hand, the robustness of OREs raises the intriguing possibility that other-race infant faces, like other-race adults faces, may not be individuated effectively; in this case, only own-race infant faces would be expected to capture attention.
To examine this issue, we used a version of a standard probe- detection task to measure the allocation of spatial attention , . Two stimuli—here, faces of different age categories (infant and adult)—were flashed simultaneously on the computer screen, each flanking a centrally placed fixation cross (see Figure 1); importantly, half of the face pairs were South Asian and half were White. South Asian and White participants viewed the face pairs and, for each pair, reported the orientation of a probe shape that appeared at either the location previously
A 2 (face age at probe location: infant, adult) 62 (face race at probe location: South Asian, White) 62 (participant race: South Asian, White) mixed-model analysis of variance (ANOVA) indicated that probe Reaction Times (RTs) were faster when probes appeared in the same location as infant faces (M = 513 ms) than adult faces (M = 524 ms), F1,38 = 13.31, P = 0.001. Impor- tantly, however, the infant-face advantage depended on distractor race and participant race, F1,38 = 4.54, P = 0.04.
Figure 2 depicts this Probe Location Age x Probe Location Race x Participant Race interaction in terms of difference RTs (RTs to probes at adult-face locations minus RTs to probes at infant-face locations; note that absolute RTs are shown in Table 1). Paired t- tests confirmed that infant faces elicited faster probe RTs than adult faces only if they matched the race of the participant: South Asian participants responded to probes more quickly when they appeared in the same location as infant face than adult face d i s t r a c t o r s f o r S o u t h A s i a n i n f a n t – a d u l t f a c e p a i r s , t 1 9 = 2 . 6 3 , P = 0 . 0 1 6 , b u t n o t f o r W h i t e i n f a n t – a d u l t f a c e p a i r s , t 1 9 = 0 . 4 6 ,
Table 1. Mean probe-detection reaction times (61 standard erro and participant race; experimental study (64 trials per condition).
r) in milliseconds as a function of distractor age, distractor race,
South Asian Participants
South Asian Distractors
South Asian Distractors
PLoS ONE | www.plosone.org
September 2010 | Volume 5 | Issue 9 | e12509