Serotonin (5HT)-induced facilitation of synaptic transmission from tail sensory neurons (SNs) to motor neurons (MNs) in the marine mollusc Aplysia provides a cellular model of short- and long-term memory for behavioral sensitization of the tail withdrawal reflex. Synaptic facilitation at these synapses occurs in three temporal phases: short-term (STF, lasting minutes), intermediate-term (ITF, l...

A robust finding in the literature is that spacing material leads to better retention than massing; however, the benefit of spacing for concept learning is less clear. When items are massed, it may help the learner to discover the relationship between instances, leading to better abstraction of the underlying concept. Two experiments addressed this question through a typical function learning t...

Repetitions that are distributed (spaced) across time prompt enhancement of a memory-related event-related potential, compared to when repetitions are massed (contiguous). Here, we used fMRI to investigate neural enhancement and suppression effects during free viewing of natural scenes that were either novel or repeated four times with massed or distributed repetitions. Distributed repetition w...

Information that is spaced over time is better remembered than the same amount of information massed together. This phenomenon, known as the spacing effect, was explored with respect to its effect on learning and neurogenesis in the adult dentate gyrus of the hippocampal formation. Because the cells are generated over time and because learning enhances their survival, we hypothesized that train...

materials. Participants were taught algebra and geometry in either a massed

The nematode Caenorhabditis elegans (C. elegans) adult hermaphrodite has 302 invariant neurons and is suited for cellular and molecular studies on complex behaviors including learning and memory. Here, we have developed protocols for classical conditioning of worms with 1-propanol, as a conditioned stimulus (CS), and hydrochloride (HCl) (pH 4.0), as an unconditioned stimulus (US). Before the co...

We developed a new protocol that induces long-term adaptation of horizontal optokinetic response (HOKR) eye movement by hours of spaced training and examined the role of protein synthesis in the cerebellar cortex in the formation of memory of adaptation. Mice were trained to view 800 cycles of screen oscillation either by 1 h of massed training or by 2.5 h to 8 d of training with 0.5 h to 1 d s...

OBJECTIVE This study aimed to resolve discrepant findings in the literature regarding the effects of massed repetition and a single long study presentation on memory in amnesia. METHOD Experiment 1 assessed recognition memory in 9 amnesic patients and 18 controls following presentation of a study list that contained items shown for a single short study presentation, a single long study presen...

This study investigated how 3-D and 2-D computer game practice and delivery as well as individual differences affect performance on two tests of mental rotation (Vandenberg Mental Rotation Test and Card Rotation Test). Sixty-one US undergraduates from the Midwest completed 4 h of either massed or distributed practice. While computer game practice improved mental rotation scores in general, wome...