Investigating infant expectation on object search tasks

Investigating infant expectation on object search tasks

Leah Murphy

2023

The current study aims to distinguish between Piaget’s (1954) theory of object understanding, highlighting the role of object permanence on A not B task performance, and Diamond’s (1985) theory highlighting the role of motor demands and lack of ability to inhibit habitual behaviours during the task. These two theories differ in their predictions for the expectations of the infants taking part, with Piaget (1954) predicting that infants’ lack of object permanence causes poor performance on the task and Diamond (1985) predicting that infants understand the movement of objects and a lack of inhibition of habitual behaviours cause error in performance. We tested 15 nine-month-old infants on a looking version of the A not B task. The use of impossible and possible outcomes was also incorporated on B trials, with the object being revealed from either the correct or incorrect location (e.g., see Ahmed & Ruffman, 1998). Infant first look direction, accumulated looking time during trials and the number of social looks initiated post-outcome, were used as measures. We found significant evidence of the ‘AB’ error during trials, with a significantly increased number of incorrect first looks on B trials. There was also a descriptive pattern showing surprise at object location reveals with increased number of social looks during B compared to A trials, though this was not significant. Accumulated looking analysis showed that infants looked longer on A than B trials, suggesting that infants expected the object to be in location B on B trials, demonstrating infants’ ability to understand objects and supporting Diamond’s (1985) theory. However, implications for a small sample size and presence of individual differences on interpretation of looking time data are discussed. Implications in theory and future research are suggested and overall, results provide support for the application of Piaget’s (1954) theory and suggest that infants have limited object understanding based on their displayed expectations during testing.

Chi-squared, Correlation, Factor analysis, Linear mixed effects modelling

3.1. Participants
In this study, 15 participants took part, aged 8 months and 12 days to 9 months and 27 days old (M = 9 months and 3 days, SD= 11.3 days). Six further infants were excluded from data analysis as they became too fussy to complete the study. Participants were recruited from the Lancaster Baby lab database, along with the Lancaster Baby lab Facebook page and were also recruited via word of mouth from guardians taking part in the
study.
3.2. Materials
The video stimuli were created using Canva software (Canva.com, 2023) and was uploaded onto ‘Habit 2’ software (see Oakes et al., 2019) to display the stimuli during testing and to measure the accumulated looking time of the infant participants. The stimuli involved a novel object obtained from the NOUN database (Horst & Hout, 2016). A camera was used to record the social looks exchanged between the infant and guardian, as well
as the direction of the infants’ first looks during testing.
3.3. Design
This study had a within-subjects design, with all participants being exposed to the same experimental conditions and the same stimuli. To counterbalance for location effects, half of the participants witnessed A trials being hidden in the box on the left, whilst the other half witnessed the object being hidden in the box on the right during A trials. The presentation of the accurate and inaccurate B trials was further counterbalanced across participants, as half of the participants viewed the inaccurate B trials first, and the other half viewed the accurate B trials first.
3.4. Ethical approval
Ethical approval for this study was granted by the departmental ethics committee (DEC) at Lancaster University. Guardians were recruited via their preferred contact method and were sent the participant information sheet to read before agreeing to take part in the study. A date and time of testing was arranged at the Babylab building at Lancaster University, via telephone or email. Upon arrival, guardians were presented with the consent form to sign and initial all points before being allowed to take part. They were also given the opportunity to ask any questions about the study and were informed that they could withdraw at any time.
After the study, the guardian received a five-pound contribution to travel costs, along with a free children’s book for the infant, as a reward for taking part in the study. The guardian also received a debrief sheet to read and to take home, providing them with all contact information of the lead researcher, if they wished to ask any questions or to withdraw from the study.
3.5. Procedure
The testing took place in a private room within the Whewell building at Lancaster University. The infant and guardian were sat in front of a computer screen with the infant sat in a highchair positioned directly in front of the screen, and the guardian sat in a chair to the side, slightly behind the infant (to allow researchers to see clearly when the infant initiated a social look). The experimenter sat behind a divider at a computer, out of sight of the infant and guardian. A social engagement video of the experimenter saying, “Let’s hide the blap, can you find the blap?” was presented to the infants at the start of the experiment and between each trial, to insert social communication and guide the attention of the infant to the screen before the stimuli were presented. The infant then watched a series of video stimuli in which a novel object appeared on the screen and moved into one of two boxes, both boxes were then covered (the object was hidden), and a there was a delay period of five seconds (see figure 1). After the delay period, both boxes were revealed, and the location of the toy was visible to the infant. Any movement of the object was accompanied by a sound to guide the attention of the infant to the object, but this sound was not present when the object was revealed to avoid any leading factors when measuring infant expectation. Instead, the occluders made a simple “whoosh” sound when they were removed, to ensure the infant was paying attention. After five identical A trials, the object was then hidden in the second location and the process was repeated consisting of six B trials. However, during the B trials, the object was hidden in the second location, but was either revealed to be in the correct (accurate) or incorrect (inaccurate) location (see figure 2). This variation in outcome was presented alternately to the infant, with the object being revealed from the incorrect location for three out of the six B trials. The study lasted for approximately 10 minutes per participant.
3.6. Behavioural coding
Infant looking time was coded online as trial lengths were infant controlled. Each trial ended when the infant looked away for four seconds. As this controlled the trial length, this was not double coded as this inherently will lead to a high agreement level. For the coding of infant first look and number of social looks, the videos recorded of the participants were saved and uploaded onto Microsoft OneDrive to be offline coded. First look was defined as the direction that the infant first looked towards once the occluder was removed and the object was revealed. On trials where the infant was not looking as the occluder was removed, the first look was defined as the direction in which they looked once their gaze returned to the screen. The first look direction was coded as correct and incorrect. The number of social looks initiated by the infant per trial was also measured during coding, defined by the infant turning towards the guardian during each trial after an outcome was revealed. Twenty percent of the videos were dual coded and there were no discrepancies between researchers during the dual coding process for first looks (r = 1, p<0.01) or social looking (r= 1, p<0.01).

.xslx

Murphy(2023)

Shiyu Pang
Yuewen Qin

open

none

English

dataset

Kirsty Dunn

Cognitive - developmental, Developmental

In this study, 15 participants took part, aged 8 months and 12 days to 9 months and 27 days old (M = 9 months and 3 days, SD= 11.3 days). Six further infants were excluded from data analysis as they became too fussy to complete the study.

Chi-squared, Correlation, Factor analysis, Linear mixed effects modelling