Alzheimer's disease (AD) is associated with progressive memory decline. Hippocampal place cells are a well understood candidate for the neural basis of one type of memory in rodents; these cells identify the animal's location in an environment and are crucial for spatial memory and navigation. We have recorded place cells in the Tg2576 mouse model of AD, and we report that aged (16 mo) but not ...

Alzheimer's disease (AD) manifests with memory loss and spatial disorientation. AD pathology starts in the entorhinal cortex, making it likely that local neural correlates of spatial navigation, particularly grid cells, are impaired. Grid-cell-like representations in humans can be measured using functional magnetic resonance imaging. We found that young adults at genetic risk for AD (APOE-ε4 ca...

Foraging and foraging-like processes are found in spatial navigation, memory, visual search, and many other search functions in human cognition and behavior. Foraging is commonly theorized using either random or correlated movements based on Lévy walks, or a series of decisions to remain or leave proximal areas known as "patches". Neither class of model makes use of spatial memory, but search p...

The hippocampal formation has been associated with a wide variety of functions including spatial navigation and planning, memory encoding and retrieval, relational processing, novelty detection, and imagination. These functions are dissimilar in terms of their behavioral consequences and modality of representation. Consequently, theoretical standpoints have focused on explaining the role of the...

Navigation is a complex cognitive ability and its structure is still poorly understood. Memory for route continuation and route order are hypothesized to be at least partially separate components of navigation ability. In the current experiment, participants studied a route in virtual reality. The dissociation between route continuation (“what turn did you make here?”) and route order (“which o...

Spatial navigation is a fascinating behavior that is essential for our everyday lives. It involves nearly all sensory systems, it requires numerous parallel computations, and it engages multiple memory systems. One of the key problems in this field pertains to the question of reference frames: spatial information such as direction or distance can be coded egocentrically-relative to an observer-...

It is now widely accepted that the entorhinal cortex (EC) plays a pivotal role in the processing of spatial information and episodic memory. The EC is segregated into two sub-regions, the medial EC (MEC) and the lateral EC (LEC) but a comprehensive understanding of their roles across multiple behavioral contexts remains unclear. Considering that it is still useful to investigate the impact of l...

Introduction: Ethanol can induce a wide spectrum of neurophysiological effects via interaction with multiple neurotransmitter systems and disruption of the balances between inhibitory and excitatory neurotransmitters. Prefrontal cortex is involved in cognitive process including working memory and is sensitive to ethanol. Present study investigates the effects of intraperitoneal (i.p.) admini...

Healthy young adults use different strategies when navigating in a virtual maze. Spatial strategies involve using environmental landmarks while response strategies involve executing a series of movements from specific stimuli. Neuroimaging studies previously confirmed that people who use spatial strategies show increased activity and gray matter in the hippocampus, while those who use response ...

The time-scale of hippocampal involvement in supporting episodic memory remains a keenly debated topic, with disagreement over whether its role is temporary or permanent. Recently, there has been interest in how navigation by hippocampally-compromised patients in environments learned long ago speaks to this issue. However, identifying patients with damage that is primarily hippocampal, control ...