8-Month-Old Infants Spontaneously Learn and Generalize Hierarchical Rules

Abstract

The ability to extract hierarchically organized rule structures from noisy environments is critical to human cognitive, social, and emotional intelligence. Adults spontaneously create hierarchical rule structures of this sort. In the present research, we conducted two experiments to examine the previously unknown developmental origins of this hallmark skill. In Experiment 1, we exploited a visual paradigm previously shown to elicit incidental hierarchical rule learning in adults. In Experiment 2, we used the same learning structure to examine whether these hierarchical-rule-learning mechanisms are domain general and can help infants learn spoken object-label mappings across different speaker contexts. In both experiments, we found that 8-month-olds created and generalized hierarchical rules during learning. Eyeblink rate, an exploratory indicator of striatal dopamine activity, mirrored behavioral-learning patterns. Our results provide direct evidence that the human brain is predisposed to extract knowledge from noisy environments, and they add a fundamental learning mechanism to what is currently known about the neurocognitive toolbox available to infants.

A novel ecological account of prefrontal cortex functional development.

“…In support of this hypothesis, recent work suggests that dlPFC may be involved in constructing abstract rules that guide learning and behavior during infancy across both linguistic and visual domains (Werchan, Collins, Frank, & Amso, 2015, 2016). In this research, 8-month-old infants were presented with simple visual stimulus-response pairings that could be learned as individual associations or as a set of hierarchical rule structures, a learning mechanism that involves PFC and its dopamine-innervated connections with striatum (Collins, Cavanagh, & Frank, 2014; Collins & Frank, 2013).…”

“…In this research, 8-month-old infants were presented with simple visual stimulus-response pairings that could be learned as individual associations or as a set of hierarchical rule structures, a learning mechanism that involves PFC and its dopamine-innervated connections with striatum (Collins, Cavanagh, & Frank, 2014; Collins & Frank, 2013). Results suggested that infants spontaneously constructed hierarchical rules when learning the simple visual stimulus-response associations, which then supported generalization in novel contexts (Werchan et al, 2015). Additional results suggested that infants also used this learning mechanism to help structure different spoken labels for the same objects into hierarchical rule structures, akin to learning in a bilingual environment.…”

Intraindividual and Interindividual Differences in Spontaneous Eye Blinking: Relationships to Working Memory Performance and Frontal EEG Asymmetry

“…Here, the relative drop in SB from Hide to Reveal could reflect that DA had been transiently elevated as infants were prompted to update and maintain their mental representations of the object's location (during Hide). A study of 8‐month‐olds observed a similar pattern in SB rates during a task that required infants to learn a new rule (Werchan, Collins, Frank, & Amso, ). In that study, infants' SB rates had increased selectively on trials following rule acquisition compared to trials that did not require the new rule.…”

Learning of hierarchical serial patterns emerges in infancy

“…This evidence comes from studies that are based on work of Badre, D'Esposito, and colleagues (Badre, ; Badre & D'Esposito, ; Badre, Kayser, & D'Esposito, ; Kayser & D'Esposito, ). This work indicates that children have the ability to use hierarchical rule sets to guide response categorizations (Amso, Haas, McShane, & Badre, ; Unger, Ackerman, Chatham, Amso, & Badre, ; Werchan et al, ). One of these studies is particularly relevant in the current context because Werchan et al () investigated whether 8‐month‐old infants can learn hierarchical rule sets.…”

“…Infancy is a time of rapid growth in many domains of cognitive functioning and, thus, it would not be surprising if this ability emerged at this time. Unfortunately, with the exception of one study (Werchan, Collins, Frank, & Amso, ), there have been no investigations of this question in infancy. The vast majority of studies to date on infant perception and learning of patterned information have focused on relatively low‐level aspects of pattern learning that is required but not sufficient for the detection of recursive, hierarchical, serial patterns.…”