The extended trajectory of hippocampal development: Implications for early memory development and disorder

How far back can we, as adults, remember details of our life experiences? Current popular and scientific beliefs are contradictory, with the latter stipulating that personal memories do not begin until the late preschool years (age 4–5 years) and the former claiming that we not only remember being born, but can also remember in utero experiences. In this review, these beliefs are examined in a scientific context and evaluated in terms of empirical data about the development of early memory. The theory proposed here is that memories for personal experiences are not possible until the advent of the cognitive self, around the age of 18 to 24 months. This age is much earlier than that proposed as the age of the earliest memories in other scientific accounts and much later than that proposed in popular beliefs about early memory. New data from a cross-sectional and longitudinal study of early memory development and the emergence of the self clearly show the origins of personal memory coincide with the emergence of the early self.

Download Full-text

Remembering New Words: Integrating Early Memory Development into Word Learning

Frontiers in Psychology ◽

10.3389/fpsyg.2013.00151 ◽

2013 ◽

Vol 4 ◽

Cited By ~ 16

Author(s):

Erica H. Wojcik

Keyword(s):

Word Learning ◽

Memory Development ◽

New Words ◽

Early Memory

Download Full-text

Trichotomous processes in early memory development, aging, and neurocognitive impairment: A unified theory.

Psychological Review ◽

10.1037/a0016963 ◽

2009 ◽

Vol 116 (4) ◽

pp. 783-832 ◽

Cited By ~ 33

Author(s):

C. J. Brainerd ◽

V. F. Reyna ◽

M. L. Howe

Keyword(s):

Neurocognitive Impairment ◽

Unified Theory ◽

Memory Development ◽

Early Memory

Download Full-text

0089 Sleep and Hippocampal Development in Early Childhood

SLEEP ◽

10.1093/sleep/zsaa056.087 ◽

2020 ◽

Vol 43 (Supplement_1) ◽

pp. A36-A36

Author(s):

T L Allard ◽

S Lokhandwala ◽

R M Spencer ◽

T Riggins

Keyword(s):

Early Childhood ◽

Memory Task ◽

Hippocampal Volume ◽

Sleep Spindles ◽

Memory Development ◽

Age And Gender ◽

Sleep Physiology ◽

Before And After ◽

Hippocampal Development ◽

And Gender

Abstract Introduction With sleep, memories are consolidated, leaving them less susceptible to interference. This process is believed to reflect transfer of memories from the hippocampus to the cortex. Research has established that naps benefit memory in typically napping children. This nap-benefit has been associated with sleep spindles during nREM2 sleep. Although research has separately related memory development to the hippocampus and to sleep, the association between hippocampal development and sleep physiology is not understood. The purpose of this investigation is to assess relations between sleep physiology and the hippocampus in early childhood. Methods Subjects are part of an ongoing longitudinal investigation. Preliminary analyses included 24 participants (Mage= 3.96 years, 14 females). Children participated in three consecutive visits, one week apart. During the first two visits, they completed a visuospatial memory task before and after a wake or nap period (order counterbalanced). Sleep physiology was assessed via polysomnography and hippocampal volumes were obtained via Freesurfer v5.1 using T1-weighted scans (.9 mm3). Results Preliminary results showed that total hippocampal volume was positively related to minutes spent in nREM2 sleep when controlling for age and gender (B=14.7, p=0.03). Further analysis showed that this relation held for left but not right hippocampus (B=10.1, p=0.01). Results also indicate a positive relation between sleep spindle count and left but not right hippocampal volume when controlling for age and gender (B=16.1, p=0.02). Conclusion Results show that greater time spent in nREM2 and greater sleep spindles across nREM2 are both related to a larger hippocampus in early childhood. These findings demonstrate an association between sleep physiology and the hippocampus during an important period of memory development, early childhood. Future analyses will assess differences in hippocampal volume between typical nappers and non-nappers at the second wave of data collection. Support Support was provided by NIH (HD094758) and NSF (BCS 1749280).

Download Full-text