Children growing up in low-income countries are at an increased risk for exposure to adverse contextual factors that may affect their cognitive development early in life. Yet, the prevalence and specific nature of cognitive problems are still poorly understood given a lack of objective, non-invasive, and field-friendly techniques for assessing early cognitive functioning in low-resource settings. In an effort to help address this gap, we carried out a study to evaluate the feasibility of using eye tracking to assess infants’ cognitive functioning in a low-income setting.
A battery of eye tracking tests were used to assess basic cognitive functions, such as anticipatory looking, sequence learning, and perception of facial expressions, of 39 Finnish and 37 Malawian infants 9 months of age. To evaluate the feasibility of using the eye tracking method in Malawi, we measured and compared the acceptability of the eye tracking method (the participants’ mothers’ appreciation of the method) and quality of the eye tracking data collected from the Malawian site to that of data collected from the Finnish site. The following conditions needed to be met in order for the method to be defined as feasible: (1) a proportion of Malawian participants similar to that of Finnish participants had to be able to complete the whole assessment, (2) a proportion of participating Malawian mothers similar to that of Finnish mothers had to report acceptance of the method, and (3) the eye tracking data quality in terms of attrition rate and proportion of valid trials had to be similar at the two sites (Malawi and Finland) and in parity with previous infancy eye tracking studies (i.e., attrition rate around 20–35% or lower, based on Ambrosini et al. 2013, Oakes and Ellis 2013, and Watanabe et al. 2012, and proportion of valid trials in each eye tracking task at greater than 70%, based on Forssman, Wass, and Leppänen 2014 and Leppänen et al. 2014).
The majority of Finnish (95%) and Malawian (92%) infants were able to complete the whole assessment. At both sites, 95% or more of the participating mothers reported acceptability of the method. Examination of eye tracking data quality between the Finnish and Malawian testing sites showed similar patterns, although the overall completion rate (Finland: 94.9%; Malawi: 91.9%) and the overall proportion of valid trials (Finland: 79.5%; Malawi: 71%) were slightly in favor of the Finnish sample. There were however no significant differences in task-specific data attrition rates between the two samples (p = .141–.946) and the attrition rates at both sites was equivalent to or better than the attrition rates reported in previous eye tracking studies with infants of similar age.
The consistency of data retention and test acceptance rate between the Finnish and Malawian samples demonstrates the feasibility of eye tracking-based assessments of infants’ cognition in low-resource settings. Based on the results from this pilot test, we believe that eye tracking is a promising tool for assessing early cognitive functions in Malawi and other low-income countries. However, further research is still needed to establish the validity of early-emerging cognitive markers as predictors of long-term health outcomes in childhood.
Washington: Food and Nutrition Technical Assistance III Project , 2015. , 28 p.