Details

Autor(en) / Beteiligte

• Ellis, Cameron T.
• Skalaban, Lena J.
• Yates, Tristan S.
• Bejjanki, Vikranth R.
• Córdova, Natalia I.
• Turk-Browne, Nicholas B.

Titel

Evidence of hippocampal learning in human infants

Ist Teil von

• Current biology, 2021-08, Vol.31 (15), p.3358-3364.e4

Ort / Verlag

England: Elsevier Inc

Erscheinungsjahr

2021

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• The hippocampus is essential for human memory.1 The protracted maturation of memory capacities from infancy through early childhood2–4 is thus often attributed to hippocampal immaturity.5–7 The hippocampus of human infants has been characterized in terms of anatomy,8,9 but its function has never been tested directly because of technical challenges.10,11 Here, we use recently developed methods for task-based fMRI in awake human infants12 to test the hypothesis that the infant hippocampus supports statistical learning.13–15 Hippocampal activity increased with exposure to visual sequences of objects when the temporal order contained regularities to be learned, compared to when the order was random. Despite the hippocampus doubling in anatomical volume across infancy, learning-related functional activity bore no relationship to age. This suggests that the hippocampus is recruited for statistical learning at the youngest ages in our sample, around 3 months. Within the hippocampus, statistical learning was clearer in anterior than posterior divisions. This is consistent with the theory that statistical learning occurs in the monosynaptic pathway,16 which is more strongly represented in the anterior hippocampus.17,18 The monosynaptic pathway develops earlier than the trisynaptic pathway, which is linked to episodic memory,19,20 raising the possibility that the infant hippocampus participates in statistical learning before it forms durable memories. Beyond the hippocampus, the medial prefrontal cortex showed statistical learning, consistent with its role in adult memory integration21 and generalization.22 These results suggest that the hippocampus supports the vital ability of infants to extract the structure of their environment through experience. [Display omitted] •Hippocampus supports statistical learning of temporal regularities in infancy•Changes in hippocampal activity emerge after only minutes of exposure•Localization of learning effects within hippocampal system similar to adults•Exploratory analyses suggest a selective role for medial prefrontal cortex Ellis et al. use fMRI to study how human infants learn from experience. Despite substantial anatomical changes over the first 2 years of life, the hippocampus supports statistical learning from early infancy. This establishes how the infant brain is prepared for rapid and prodigious learning throughout development.