Search Results (3)

An animal’s ability to navigate its home range in search of essential resources is a key aspect of its ecology. To reach these resources, animals employ varying navigational processes depending on their exocentric or egocentric view of their environment. The goal of this study was to determine if the Javan slow loris (Nycticebus javanicus), a nocturnal arboreal primate found in southeast Asia, uses some form of cognitive map and spatial memory while navigating their environment. Using behavioural and GPS data of six males and seven females collected at the Little Fireface Project field station based in West Java, Indonesia, we measured their frequency of revisiting important feeding trees, route overlap, and points where individuals significantly changed directions. We found that all individuals predominantly used four tree species while feeding and foraging. The lorises also displayed a high level of route overlap, leading us to conclude that they likely utilize a route-based cognitive map where certain landmarks are integral to their nightly movement. Few studies have specifically focused on strepsirrhine spatial cognition in the wild; here, we show the navigational mechanism used by the Javan slow loris to reach distant/out-of-sight resources. The evident reliance on spatial cognition in a strepsirrhine species suggest that it could be an important selective pressure for primates at the earliest stages of primate cognitive evolution. In addition to the importance of spatial memory in theoretical discourse, understanding slow loris movement has practical applications to conservation, particularly regarding the numerous translocations undertaken by individuals rescued from the illegal wildlife trade. We discuss the importance of considering soft release training and monitoring in such releases. Full article

The goal of the current study was to show the existence of distinct types of survey-based environmental representations, egocentric and allocentric, and provide experimental evidence that they are formed by different types of navigational strategies, path integration and map-based navigation, respectively. After traversing an unfamiliar route, participants were either disoriented and asked to point to non-visible landmarks encountered on the route (Experiment 1) or presented with a secondary spatial working memory task while determining the spatial locations of objects on the route (Experiment 2). The results demonstrate a double dissociation between the navigational strategies underlying the formation of allocentric and egocentric survey-based representation. Specifically, only the individuals who generated egocentric survey-based representations of the route were affected by disorientation, suggesting they relied primarily on a path integration strategy combined with landmark/scene processing at each route segment. In contrast, only allocentric-survey mappers were affected by the secondary spatial working memory task, suggesting their use of map-based navigation. This research is the first to show that path integration, in conjunction with egocentric landmark processing, is a distinct standalone navigational strategy underpinning the formation of a unique type of environmental representation—the egocentric survey-based representation. Full article

Individuals with agoraphobia exhibit impaired exploratory activity when navigating unfamiliar environments. However, no studies have investigated the contribution of visuospatial working memory (VSWM) in these individuals’ ability to acquire and process spatial information while considering the use of egocentric and allocentric coordinates or environments with or without people. A total of 106 individuals (53 with agoraphobia and 53 controls) navigated in a virtual square to acquire spatial information that included the recognition of landmarks and the relationship between landmarks and themselves (egocentric coordinates) and independent of themselves (allocentric coordinates). Half of the participants in both groups navigated in a square without people, and half navigated in a crowded square. They completed a VSWM test in addition to tasks measuring landmark recognition and egocentric and allocentric judgements concerning the explored square. The results showed that individuals with agoraphobia had reduced working memory only when active processing of spatial elements was required, suggesting that they exhibit spatial difficulties particularly in complex spatial tasks requiring them to process information simultaneously. Specifically, VSWM deficits mediated the relationship between agoraphobia and performance in the allocentric judgements. The results are discussed considering the theoretical background of agoraphobia in order to provide useful elements for the early diagnosis of this disorder. Full article