Poster #31 - Examining spatial rotation processing in infancy

• In Event: 2-055 - Poster Session 06
  In Poster Session: PS 06 Section - Cognitive Processes

Integrative Statement

In adulthood, the time required to visualize two objects rotating into alignment linearly relates to the angular disparity between the two objects, demonstrating a mental analog to the perception of physical rotation (Shepard & Metzler, 1971). Although the ability to engage in the mental rotation of objects has been well studied in older children and adults, it is unclear whether infants exhibit mental rotation processes similar to those observed later in life (Frick, Möhring, & Newcombe, 2014). To shed light on the development of mental rotation processes, we presented 51 infants (24 female) between 6 and 12 months of age (M = 8.24 months) with a change-detection task designed to assess their sensitivity to varying angular disparities in the orientation of a rotating stimulus. During the task, infants were simultaneously shown two image streams that contained a single two-dimensional stimulus appearing in different orientations along the picture plane (see Figure 1). In one stream, orientations were constrained to an arc of 180°, whereas in the other stream (i.e., the changing stream), the stimulus variably appeared within the expected 180° arc and in unexpected orientations outside of the expected arc. We compared infants’ relative looking times to the changing stream within each condition. The three conditions (15° disparity, 45° disparity, and 75° disparity) differed in the angular disparity between the expected orientation of the stimulus and its unexpected orientation, allowing us to directly compare whether infants responded differentially to larger angular disparities, as seen in adulthood. All infants completed four trials in the 75°-disparity condition and four trials in one of the other two conditions. Thus, 29 infants completed both the 75°-disparity and 45°-disparity conditions, and 22 infants completed both the 75°-disparity and 15°-disparity conditions (data collection is ongoing for all conditions).

A mixed-model ANOVA revealed that infants’ change-detection scores varied significantly by condition: F = 4.94, p = .031, ηp2 = .09. However, infants’ change-detection scores did not scale linearly with the angular disparity between the stimuli, as change-detection scores were greatest in the 45° condition, although they differed significantly from chance in both the 15° and 45° conditions (ps <.05, ds >.40). This suggests that infants may develop expectations about the rotational trajectories of objects during the change-detection task, but may not display evidence of mental rotation processes specifically. Furthermore, the effect of condition did not vary by gender (F = 0.28, p = .602), and no gender differences in change-detection scores were observed within any condition (ps >.81, ds <.08). Therefore, in contrast to some previous findings of gender differences in early spatial processing (e.g., Lauer et al., 2015; Moore & Johnson, 2008; Quinn & Liben, 2008), girls and boys were equally sensitive to the unexpected orientation presented in the changing stream. Future directions for this research include examining a number of correlates of infants’ change-detection performance to determine whether individual-difference factors, including infants’ short-term memory performance, motor functioning, and play experiences, relate to their developing spatial skills during the first year of life.

Authors

• Adna Jaganjac, Johns Hopkins University
  Presenting Author

• Jillian E Lauer, New York University
  Non-Presenting Author

• Patricia Bauer, Emory University
  Non-Presenting Author