Differential impact of Socioeconomic Status on Associative and Reward Learning in Infancy

• In Event: 1-218 - How the Environment Shapes Learning Across Development

Integrative Statement

The amount of learning that takes place in infancy is arguably unmatched at any other point in the human lifetime. Learning systems play a critical role in these seismic shifts in neural and cognitive development. This talk will focus on the impact of socioeconomic status (SES) in infant learning. In early work, we showed that spatial attention is not susceptible to SES at 9 months, but that recognition memory is susceptible to the effects of SES. In addition, we found that attention may serve as a mechanism of resilience whereby items encoded under conditions of distractor suppression are remembered later similarly regardless of SES (Markant et al., 2015). These data raised the possibility that variability in information-gathering mechanisms in infancy may be a source of important plasticity. Here we probe this idea further in an examination of the impact of SES on reward versus associative learning in the same group of 7-month-old infants.
In previous work, we capitalized on the reward value of mothers to establish the origins of reward learning mechanisms in infancy. We presented 7-month-old infants with several arbitrary shape cues that predicted the location of video stimuli (stimulus-response or S-R mappings). The videos parametrically increased either in social-emotional reward value (mother, female stranger, male stranger) or in visual attention value (dynamic cartoon, slowed version of the same cartoon, and static image of same cartoons). We observed the strongest learning (i.e., faster latency) from the high social-emotional reward (mother) and evidence of transfer of the pupillary response from the mother onto a mother-predictive arbitrary shape cue (reward transfer). Furthermore, the extent of learning and transfer was predicted by individual differences in infants’ eye blink rates (EBR), indicating reward, to their mother’s video. We found no evidence of learning to pair the cartoon videos with the target location, and minimal evidence of learning otherwise from the stranger’s face.

Relevant to susceptibility and resilience to environmental influence, the data collected in this study offer an opportunity to examine whether learning to associate the stranger’s face with a target location through an associative learning mechanism (associative S-R mapping) and learning to map mother’s face with a target location through a reward learning mechanism (reward S-R mapping) are influenced by SES. We found that that infants’ S-R mappings through associative mechanisms are susceptible to SES. Linear regression models, controlling for the effects of age and baseline EBR, showed different effects for reward learning (arbitrary cue predicting mother’s face location) and non-rewarded associative learning (arbitrary cue predicting stranger’s face location). Infants from higher SES homes had significantly more negative slopes (faster learning with trial presentations) to the stranger’s face. In contrast, slopes for learning the S-R associations when the mother was the target stimulus, i.e., reward learning, did not differ by SES in the same sample of 7-month-old infants. These data are important for understanding how individual differences in the interplay of vulnerable and compensatory mechanisms in infancy may shape subsequent outcomes into early childhood.

Authors

• Kristen Tummeltshammer, Brown University
  Presenting Author

• Dima Amso, Brown University
  Non-Presenting Author