Head and eye movements affect object processing in 4‐month‐old infants more than an artificial orientation cue

Abstract

This study investigates the effects of attention-guiding stimuli on 4-month-old infants' object processing. In the human head condition, infants saw a person turning her head and eye gaze towards or away from objects. When presented with the objects again, infants showed increased attention in terms of longer looking time measured by eye tracking and an increased Nc amplitude measured by event-related potentials (ERP) for the previously uncued objects versus the cued objects. This suggests that the uncued objects were previously processed less effectively and appeared more novel to the infants. In a second condition, a car instead of a human head turned towards or away from objects. Eye-tracking results did not reveal any significant difference in infants' looking time. ERPs indicated only a marginally significant effect in late slow-wave activity associated with memory encoding for the uncued objects. We conclude that human head orientation and gaze direction affect infants' object-directed attention, whereas movement and orientation of a car have only limited influence on infants' object processing.

Theta- and alpha-band EEG activity in response to eye gaze cues in early infancy

“…Alpha desynchronization is a sensitive measure for attentional mechanisms that suppress irrelevant information and therefore focus attention on relevant information (Ward, 2003). Social cues such as eye gaze or head turn can guide infants' attention and can lead to enhanced memory encoding of cued objects in 4-month-olds (Hoehl, Wahl, et al, 2014;Hood, Willen, & Driver, 1998;Reid & Striano, 2005;Reid et al, 2004;Wahl et al, 2013). Thus, alpha desynchronization in the object-directed condition may reflect focused attention to gaze cued objects and thereby be related to social learning processes (Hoehl, Michel, et al, 2014).…”

“…Thereby it could enable or at least facilitate object learning in such situations. Similar processes might take place already at 4 months as infants differentiate between eye gazes toward and away from objects and build stronger memory representations for cued objects (Hoehl et al, 2008;Hoehl, Wahl, et al, 2014;Reid & Striano, 2005;Reid et al, 2004;Wahl et al, 2013). In the current study, eye gaze that is directed toward an object identifies it as an object that is of high relevance for the infant.…”

“…In a live paradigm measuring looking times, infants at 7 and 9 but not at 4 and 5 months of age showed enhanced object processing in a joint attention situation (Cleveland, Schug, & Striano, 2007;. Studies that presented similar stimuli on a screen found that infants were able to use social cues for object learning already at 4 months (Hoehl, Wahl, & Pauen, 2014;Reid & Striano, 2005;Reid, Striano, Kaufman, & Johnson, 2004;Wahl, Michel, Pauen, & Hoehl, 2013). These studies compared ERPs and looking times in response to objects that were previously cued by another person's eye gaze and/or head turn with objects that were not cued.…”

Further Evidence for Continuity in Infants' Joint Attention Development

“…Using a live joint attention ERP paradigm adapted from Striano, Reid, and Hoehl [2006], Parise et al [2008] showed that even 5-month-olds' brain responses to objects are increased by a triadic interaction involving mutual gaze. When infants are presented short movies of adults turning either isolated eye gaze or combined head and gaze direction towards objects within the infants' immediate visual field, effects on object processing are even found in 4-month-old infants [Hoehl, Wahl, Michel, & Striano, 2012;Reid & Striano, 2005;Reid, Striano, Kaufman, & Johnson, 2004;Wahl, Michel, Pauen, & Hoehl, 2013]. Rather than speaking for abrupt changes in infants' joint attention capabilities, these results indicate continuity in infants' use of triadic interactions to focus their attention and facilitate object encoding throughout the first year of infancy.…”

The Development of Social Attention in Human Infants

“…Although these studies are suggestive of social learning from eye gaze and joint attention (see Reid & Dunn,Chap. 3,this volume) for an expanded discussion of this issue), they lack converging behavioral evidence confirming that the cortical response is functionally significant (for an exception, see Wahl, Michel, Pauen, & Hoehl, 2013).…”