When learning goes beyond statistics: Infants represent visual sequences in terms of chunks

• Published in: Cognition Vol. 178; pp. 92 - 102
• Main Authors: Slone, Lauren K., Johnson, Scott P.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.09.2018; Elsevier Science Ltd
• Subjects: Babies; Chunking; Discrimination, Psychological; Embedded items; Female; Humans; Illusory items; Infant; Infants; Learning; Male; Mathematical models; Models, Psychological; Models, Statistical; Pattern Recognition, Visual; Probability; Sensory integration; Sequences; Statistical analysis; Statistical learning; Statistical methods; Transitional probability; Visual discrimination learning; Visual perception; Illusory items; Infants; Chunking; Transitional probability; Statistical learning; Embedded items
• ISSN: 0010-0277; 1873-7838
• DOI: 10.1016/j.cognition.2018.05.016

•Infants’ visual statistical learning is best captured by chunking models.•Infants discriminated units from statistically matched illusory and embedded units.•Infants built up representations of larger chunks with increased stimulus exposure.•Chunking may represent a general feature of perceptual learning. Much research has documented infants’ sensitivity to statistical regularities in auditory and visual inputs, however the manner in which infants process and represent statistically defined information remains unclear. Two types of models have been proposed to account for this sensitivity: statistical models, which posit that learners represent statistical relations between elements in the input; and chunking models, which posit that learners represent statistically-coherent units of information from the input. Here, we evaluated the fit of these two types of models to behavioral data that we obtained from 8-month-old infants across four visual sequence-learning experiments. Experiments examined infants’ representations of two types of structures about which statistical and chunking models make contrasting predictions: illusory sequences (Experiment 1) and embedded sequences (Experiments 2–4). In all four experiments, infants discriminated between high probability sequences and low probability part-sequences, providing strong evidence of learning. Critically, infants also discriminated between high probability sequences and statistically-matched sequences (illusory sequences in Experiment 1, embedded sequences in Experiments 2–3), suggesting that infants learned coherent chunks of elements. Experiment 4 examined the temporal nature of chunking, and demonstrated that the fate of embedded chunks depends on amount of exposure. These studies contribute important new data on infants’ visual statistical learning ability, and suggest that the representations that result from infants’ visual statistical learning are best captured by chunking models.