Development and sex differentiation impart an organizational influence on the neuroanatomy and behavior of mammalian species. Prior studies suggest that brain regions associated with fear motivated defensive behavior undergo a protracted and sex-dependent development. Outside of adult animals, evidence for developmental sex differences in…

Episodic memories for autobiographical events that happen in unique spatiotemporal contexts are central to defining who we are. Yet, before 2 years of age, children are unable to form or store episodic memories for recall later in life, a phenomenon known as infantile amnesia. Here, we studied the development of allocentric spatial memory, a…

Memory improves when encoding and retrieval processes overlap. Here, we investigated how the neural bases of long-term memory encoding vary as a function of the degree to which functional processes engaged at study are engaged again at test. In an incidental learning paradigm, electrical brain activity was recorded from the scalps of healthy…

Four experiments explored the processes that bridge between referent selection and word learning. Twenty-four-month-old infants were presented with several novel names during a referent selection task that included both familiar and novel objects and tested for retention after a 5-min delay. The 5-min delay ensured that word learning was based on…

Children's memory of single infant experience was evaluated. At 6.5 months, infants participated in study of reaching in light and dark for sounding object. Children repeated dark procedure in laboratory when they were either one year or two years older. Older children with infant experience reached and grasped the sounding object significantly…

In this study, we used event-related potentials (ERPs) to evaluate the contribution of surface color and color knowledge information in object identification. We constructed two color-object verification tasks--a surface and a knowledge verification task--using high color diagnostic objects; both typical and atypical color versions of the same…

The influence of negative affect on the retrieval of information from memory during infancy was investigated in two studies through the use of an operant conditioning paradigm. The procedure used, known as "mobile conjugate reinforcement," involves a free operant task in which an infant is reinforced for footkicking by the movement of an…

Three experiments examined characteristics of a stimulus-cueing retrieval from long-term memory for 3-month olds. Used mobiles displaying either Qs (feature-present stimuli) or Os (feature-absent stimuli) and tested 24 hours later. Findings indicated that target-distractor similarity constraints, whether or not a feature-present stimulus, would…

The fear conditioning paradigm is used to investigate the roles of various genes, neurotransmitters, and substrates in the formation of fear learning related to contextual and auditory cues. In the brain, nitric oxide (NO) produced by neuronal nitric oxide synthase (nNOS) functions as a retrograde neuronal messenger that facilitates synaptic…

Three experiments examined the memory-preserving effects of reactivation and reinstatement reminders following 6-month-olds' learning and forgetting of an operant task. Findings indicated that a single reactivation reminder extended infants' memory of an operant mobile task for 2 weeks, a single reinstatement extended it for 4 weeks. A single…

The present study was designed to determine whether a reactivation procedure (consisting of the experimenter's manipulation of a previously experienced overhead crib mobile) would alleviate infant's poor retention after a 14-day interval. It is concluded that forgetting by young infants may result from failures in retrieval, and not failures in…

Two experiments examined factors of recall in one- to two-year olds. Results suggest that the strength of organization of an event representation, rather than retention interval, is a major factor in long-term recall between one and two years old. (ETB)