A socioecological model of neighborhood disorder, religious attendance, and sleep efficiency.

Objectives: Drawing on the socioecological model of sleep health, we formally examine the association between neighborhood disorder and sleep efficiency. While most studies focus on direct associations with neighborhood context, we also consider whether the relationship between religious attendance and sleep efficiency varies as a function of neighborhood disorder.

Design: We use ordinary least squares regression to model cross-sectional survey data.

Prevalence of Helicobacter pylori infection in the general population in Wuzhou, China: a cross-sectional study.

Background: Helicobacter pylori (H. pylori) is a global infectious carcinogen. We aimed to evaluate the prevalence of H.

The neural correlates of memory integration in value-based decision-making during human spatial navigation.

In daily life, we often make decisions based on relative value of the options, and we often derive these values from segmenting or integrating the outcomes of past episodes in memory. The neural correlates involved in value-based decision-making have been extensively studied in the literature, but few studies have investigated this topic in decisions that require segmenting or integrating episodic memory from related sources, and even fewer studies examine it in the context of spatial navigation. Building on the computational models from our previous studies, the current study investigates the neural substrates involved in decisions that require people either segment or integrate wayfinding outcomes involving different goals, across virtual spatial navigation tasks with differing demands.

Effects of Acute Stress on Rigid Learning, Flexible Learning, and Value-Based Decision-Making in Spatial Navigation.

The current study investigated how stress affects value-based decision-making during spatial navigation and different types of learning underlying decisions. Eighty-two adult participants (42 females) first learned to find object locations in a virtual environment from a fixed starting location (rigid learning) and then to find the same objects from unpredictable starting locations (flexible learning). Participants then decided whether to reach goal objects from the fixed or unpredictable starting location.

A comparison of reinforcement learning models of human spatial navigation.

Reinforcement learning (RL) models have been influential in characterizing human learning and decision making, but few studies apply them to characterizing human spatial navigation and even fewer systematically compare RL models under different navigation requirements. Because RL can characterize one's learning strategies quantitatively and in a continuous manner, and one's consistency of using such strategies, it can provide a novel and important perspective for understanding the marked individual differences in human navigation and disentangle navigation strategies from navigation performance. One-hundred and fourteen participants completed wayfinding tasks in a virtual environment where different phases manipulated navigation requirements.

Episodic memory integration shapes value-based decision-making in spatial navigation.

Valued-based decision-making has been studied for decades in myriad topics such as consumer spending and gambling, but very rarely in spatial navigation despite the link between the two being highly relevant to survival. Furthermore, how people integrate episodic memories, and what factors are related to the extent of memory integration in value-based decision-making, remain largely unknown. In the current study, participants learned locations of various objects in a virtual environment and then decided whether to reach goal objects from familiar starting locations or unpredictable ones, with different penalties associated with each option.

Environmental overlap influences goal-oriented coding of spatial sequences differently along the long-axis of hippocampus.

When navigating our world we often first plan or retrieve a route to our goal, avoiding alternative paths to other destinations. Inspired by computational and animal models, we have recently demonstrated evidence that the human hippocampus supports prospective spatial coding, mediated by interactions with the prefrontal cortex. But the relationship between such signals and the need to discriminate possible routes based on their goal remains unclear.

Performance in Real World- and Virtual Reality-Based Spatial Navigation Tasks in Patients With Vestibular Dysfunction.

Objective: This study evaluated whether vestibular dysfunction is associated with reduced spatial navigation performance.

Study Design: Cross-sectional study.

Setting: Otolaryngology Clinic in the Johns Hopkins Outpatient Center and an analogous virtual reality (VR) environment.

Evidence for a gradient within the medial temporal lobes for flexible retrieval under hierarchical task rules.

A fundamental question in memory research is how the hippocampus processes contextual cues to retrieve distinct mnemonic associations. Prior research has emphasized the importance of hippocampal-prefrontal interactions for context-dependent memory. Our fMRI study examined the human medial temporal lobes (MTL) and their prefrontal interactions when retrieving memories associated with hierarchically organized task contexts.

A feasibility trial of gamma sensory flicker for patients with prodromal Alzheimer's disease.

Introduction: We and collaborators discovered that flickering lights and sound at gamma frequency (40 Hz) reduce Alzheimer's disease (AD) pathology and alter immune cells and signaling in mice. To determine the feasibility of this intervention in humans we tested the safety, tolerability, and daily adherence to extended audiovisual gamma flicker stimulation.

Methods: Ten patients with mild cognitive impairment due to underlying AD received 1-hour daily gamma flicker using audiovisual stimulation for 4 or 8 weeks at home with a delayed start design.

Environmental overlap and individual encoding strategy modulate memory interference in spatial navigation.

There has been great interest in how previously acquired knowledge interacts with newly learned knowledge and how prior knowledge facilitates semantic and "schema" learning. In studies of episodic memory, it is broadly associated with interference. Very few studies have examined the balance between interference and facilitation over the course of temporally-extended events and its individual differences.

The role of working memory capacity in spatial learning depends on spatial information integration difficulty in the environment.

A substantial amount of research has been conducted to uncover factors underlying the pronounced individual differences in spatial navigation. Spatial working memory capacity (SWM) is shown to be one important factor. In other domains such as reading comprehension, the role of working memory capacity in task performance differences depends on the difficulty of other task demands.

Heterogeneous correlations between hippocampus volume and cognitive map accuracy among healthy young adults.

Marked individual differences in the ability to mentally map our environment are pronounced not only among people of different ages or clinical conditions, but also within healthy young adults. Previous studies have shown that hippocampus size positively correlated with spatial navigation ability in healthy young adults, navigation experts, and patients with hippocampus lesions. However, a recent pre-registered study (Weisberg, Newcombe, & Chatterjee, 2019) with a large sample size (n = 90) did not observe this correlation in healthy young adults.

Manipulating the visibility of barriers to improve spatial navigation efficiency and cognitive mapping.

Previous studies from psychology, neuroscience and geography showed that environmental barriers fragment the representation of the environment, reduce spatial navigation efficiency, distort distance estimation and make spatial updating difficult. Despite these negative effects, limited research has examined how to overcome barriers and if individual differences mediate their causes and potential interventions. We hypothesize that the reduced visibility caused by barriers plays a major role in accumulating error in spatial updating and encoding spatial relationships.

Environmental Barriers Disrupt Grid-like Representations in Humans during Navigation.

Environmental barriers fundamentally shape our behavior and conceptualization of space [1-5]. Evidence from rodents suggests that, in contrast to an open-field environment, where grid cells exhibit firing patterns with a 6-fold rotational symmetry [5, 6], barriers within the field abolish the 6-fold symmetry and fragment the grid firing fields into compartmentalized repeating "submaps" [5]. These results suggest that barriers may exert their influence on the cognitive map through organization of the metric representation of space provided by entorhinal neurons.

Acquisition and transfer of spatial knowledge during wayfinding.

In the current study, we investigated the ways in which the acquisition and transfer of spatial knowledge were affected by (a) the type of spatial relations predominately experienced during learning (routes determined by walkways vs. straight-line paths between locations); (b) environmental complexity; and (c) the availability of rotational body-based information. Participants learned the layout of a virtual shopping mall by repeatedly searching for target storefronts located in 1 of the buildings.

Virtual Orientation Overrides Physical Orientation to Define a Reference Frame in Spatial Updating.

Previous studies showed that people could use either an egocentric or allocentric reference frame in spatial updating with body-based cues (i.e., physical body movements), but the adopted reference frame was anchored by the physical egocentric front when body-based cues were constrained.

Reference frames in spatial updating when body-based cues are absent.

The current study investigated the reference frame used in spatial updating when idiothetic cues to self-motion were minimized (desktop virtual reality). In Experiment 1, participants learned a layout of eight objects from a single perspective (learning heading) in a virtual environment. After learning, they were placed in the same virtual environment and used a keyboard to navigate to two of the learned objects (visible) before pointing to a third object (invisible).

Spatial Updating Strategy Affects the Reference Frame in Path Integration.

This study investigated how spatial updating strategies affected the selection of reference frames in path integration. Participants walked an outbound path consisting of three successive waypoints in a featureless environment and then pointed to the first waypoint. We manipulated the alignment of participants' final heading at the end of the outbound path with their initial heading to examine the adopted reference frame.

Bias in Human Path Integration Is Predicted by Properties of Grid Cells.

Accurate wayfinding is essential to the survival of many animal species and requires the ability to maintain spatial orientation during locomotion. One of the ways that humans and other animals stay spatially oriented is through path integration, which operates by integrating self-motion cues over time, providing information about total displacement from a starting point. The neural substrate of path integration in mammals may exist in grid cells, which are found in dorsomedial entorhinal cortex and presubiculum and parasubiculum in rats.