Looking Behavior at Test and Relational Memory in 6‐Month‐Old Infants

Abstract

Small‐scale eye‐tracking research lends support to behavioral studies of relational memory by 6 months of life. Here, in the largest eye‐tracking test of relational memory to date (n = 276), we replicate these findings and examine the impact of excluding data based on looking behavior characteristics at test. Past work examining infants' preferential looking toward arbitrary‐paired objects and scenes has excluded infants from analysis based upon “insufficient looking” at test. Yet, research suggests that variation in looking behavior may be associated with looking patterns during encoding, as well as trait‐like differences in visual and cognitive processing. Similar to past research, we observed evidence for relational memory among 6‐month‐olds. In keeping with past research, when infants were excluded based on “insufficient looking,” we observed evidence for relational memory only when infants were tested immediately. However, when exclusion criteria were relaxed, infants specifically demonstrated preferential looking during a presumably more difficult delay‐plus‐interference condition. Moreover, analyses revealed that looking behavior during encoding was associated with looking behavior at test. Together, results suggest that infants do possess rudimentary relational memory capabilities, but that experimenters' ability to detect these capabilities is influenced by both experimental conditions and individual differences in looking behavior.

The extended trajectory of hippocampal development: Implications for early memory development and disorder

“…Because PRC is known for conjoining featural details, it may have conjoined the elements of the display in a rudimentary, unitized form with looking at test captured by a change in the location of the face on the scene that was not supported by enough featural detail to disrupt memory altogether. This interpretation is consistent with Richmond and Power (2014) who replicated the effects of Richmond and Nelson (2009) in 6- but not 12-month-olds (see also Chong et al, 2015 ). The null effect for the older age in Richmond and Power could have arisen from increased PRC development reflecting a large enough discrepancy between the test display and the unitized memory of the encoding display to disrupt performance altogether.…”

“…These varied developmental trajectories led these authors to propose that maturation of these substructures should reflect the emergence of different memory processes in development. A challenge for this proposal is how to reconcile this protracted view of development with recent reports of early memory function in tasks known to elicit hippocampal processing in adults, such as relational binding of a face to a scene ( Richmond and Nelson, 2009 , Richmond et al, 2004 , Chong et al, 2015 ), memory for spatial relations between objects in a display ( Richmond et al, 2015 ), remembering temporal relations between events in a scene ( Barr et al, 1996 , Bauer et al, 2003 ), relational inference ( Rovee-Collier and Giles, 2010 ), demonstrations of context effects ( Richmond et al, 2004 , Edgin et al, 2014 ), and better retention after sleep than after a similar period of wakefulness ( Friedrich et al, 2015 , Seehagen et al, 2015 ).…”

Visual short-term memory guides infants’ visual attention

“…Although the trials were less than 3 s in duration, the music clips sounded natural—2 to 3 s is sufficiently long for a complete phrase or two of music. This procedure has been successfully used in several previous studies (Brandone, Horwitz, Aslin, & Wellman, 2014; Chong, Richmond, Wong, Qiu, & Rifkin-Graboi, 2015; Kwon et al, 2016). …”

Reactive and anticipatory looking in 6-month-old infants during a visual expectation paradigm

“…Data were acquired via a Tobii eyetracker, and the Visual Expectation task was presented in a counter-balanced order with two other eye tracking tasks (relational binding, as described in [2] and habituation followed by a visual paired comparison, as described in [6] ), but occurred after the encoding portion of a deferred memory task and before an electrophysiology task, a parent-child behavioral observation task, and the retrieval portion of the deferred memory task (see Cai et al [1] for a more complete description of this laboratory visit and [4] for work examining this Visual Expectation task in relation to parenting behavior, also examined during the laboratory session).…”

“…To ensure that values were not influenced by perseveration, data were only included from trials in which the stimulus did not appear on the same side of the screen as in the preceding trial ( M =10.1 trials, SD =2.0, across all infants administered the visual expectation paradigm). As it takes up to 133 ms for an infant to physically shift his/her gaze in reaction to a stimulus [3] , we then excluded data from trials in which the first fixation on the correct AOI occurred within 133 ms of stimulus onset, as these shifts could not have been reactive in nature. Thus, after accounting for trials during which there was no reactive look to the stimulus and trials for which gaze data were missing (either due to the infant looking away or due to the eye-tracker's inability to detect the infant's gaze), this variable included, on average, 4.4 ( SD =2.6) valid trials across all infants who were administered the visual expectation paradigm.…”