In recent years, there have been intensive debates on whether healthy adults acquire new word knowledge through fast mapping (FM) by a different mechanism from explicit encoding (EE). In this study, we focused on this issue and investigated to what extent reteninterval, prior knowledge (PK), and lure type modulated memory after FM and EE. Healthy…

In three experiments, the nature of the interaction between multiple memory systems in rats solving a variation of a spatial task in the water maze was investigated. Throughout training rats were able to find a submerged platform at a fixed distance and direction from an intramaze landmark by learning a landmark-goal vector. Extramaze cues were…

Learning to navigate toward a goal is an essential skill. Place learning is thought to rely on the ability of animals to associate the location of a goal with surrounding environmental cues. Using the Morris water maze, a task popularly used to examine place learning, we demonstrate that distal cues provide animals with distance and directional…

Training paradigms affecting "Aplysia" withdrawal reflexes cause changes in gene expression leading to long-term memory formation in primary mechanoafferents that initiate withdrawal. Similar mechanoafferents are also found in the buccal ganglia that control feeding behavior, raising the possibility that these mechanoafferents are a locus of…

The hippocampus has been proposed to support a cognitive map, a mental representation of the spatial layout of an environment as well as the nonspatial items encountered in that environment. In the present study, we recorded simultaneously from 43 to 61 hippocampal pyramidal cells as rats performed an object recognition memory task in which novel…

Humans and animals form internal representations of external space based on their own body movement (dead reckoning) as well as external landmarks. It is poorly understood, however, how different types of information are integrated to form a unified representation of external space. To examine the role of dentate gyrus (DG) in this process, we…

During visually guided grasping movements, visual information is transformed into motor commands. This transformation is known as the "visuomotor map." To investigate limitations in the short-term plasticity of the visuomotor map in normal humans, we studied the maximum grip aperture (MGA) during the reaching phase while subjects grasped objects…

We recently described a critical role for adrenergic signaling in the hippocampus during contextual and spatial memory retrieval. To determine which neurons are activated by contextual memory retrieval and its sequelae in the presence and absence of adrenergic signaling, transcriptional imaging for the immediate-early gene "Arc" was used in…

Impairment of hippocampal function precedes frontal and parietal cortex impairment in human Alzheimer's disease(AD). Neurotrophins are critical for behavioral performance and neuronal survival in AD. We used complex and radial mazes to assess spatial orientation and learning in wild-type and B6-Tg(ThylAPP)23Sdz (APP23) animals, a transgenic mouse…