The path more travelled: Time pressure increases reliance on familiar route-based strategies during navigation

Navigating large-scale environments involves dynamic interactions between the physical world and individuals’ knowledge, goals, and strategies. Time pressure can result from self-imposed goals or relatively dynamic situational factors that induce varied constraints. While time pressure is ubiquitous in daily life and has been shown to influence affective states, cost-benefit analyses, and strategy selection, its influence on navigation behaviour is unknown. The present study examined how introducing varied time constraints during virtual urban navigation would influence spatial strategies and impact the efficiency and effectiveness of goal-directed wayfinding. Participants learned a large-scale urban virtual environment by wayfinding between a series of 20 successive landmark goals (e.g., You have reached the Theater. Now find the Bank.). A day later, they again performed the same task, but landmark-to-landmark trials were characterized by conditions of low-, moderate-, or high-pressure time limits as quantified by a pilot experiment. As time pressure increased, participants more likely navigated along previously experienced paths and less likely travelled in the global direction of the destination. Results suggest strategy shifts under time constraints that increase reliance on egocentric, route-based strategies and decrease reliance on global configural knowledge, probably in an attempt to reduce cognitive demands and support performance under pressure.     

Spatial frameworks in imagined navigation

The spatial framework model proposes that people use the extensions of their body axes as a reference frame for encoding spatial layouts in memory, and that the physical and functional properties of our bodies and the world determine the accessibility of egocentric locations from memory representations. The present experiment provides evidence that spatial framework results can be obtained even with perceptual scenes that contain no objects to be held in memory. Using a paradigm in which participants interpreted direction and distance information to follow a mental path within a checkerboard grid, the present study shows that spatial framework results are obtained when reasoning occurs from a perspective that is misaligned with respect to the physical reference frame of the participant. The theoretical implications of these results are discussed.     

Spatial language influences memory for spatial scenes

Does language influence recognition for spatial scenes? In Experiments 1 and 2, participants viewed ambiguous pictures, with or without spatial sentences. In a yes—no recognition task, only the spatial sentences group made more false alarms toward the center of the spatial category than in the other direction; three other comparison groups showed no such tendency. This shift toward the core of the semantic category suggests that spatial language interacted with perceptual information during encoding. In Experiment 3, we varied the materials to test the interactive encoding account against a separate encoding account in which separately stored sentences are accessed during picture recognition. The results support the interactive encoding account in which spatial language influences the encoding and memory of spatial relations.     

Neuroevolution-based autonomous robot navigation: A comparative study

The field of neuroevolution has achieved much attention in recent years from both academia and industry. Numerous papers have reported its successful applications in different fields ranging from medical domain to autonomous systems. However, it is not clear which evolutionary optimization techniques lead to the best results. In this paper, multilayer perceptron (MLP) neural networks (NNs) are trained and optimized using four advanced bio-inspired evolutionary algorithms (EA). The algorithms are Multi-Verse Optimizer (MVO), Moth-flame optimization (MFO), Cuckoo Search (CS) and Particle Swarm Optimization (PSO). Each algorithm is equipped with two operators: evolutionary population dynamics and mutation, which impact on exploration and exploitation. Optimized MLPs are then used for the navigation of an autonomous robot. Accuracy and area under the curve metrics are used for the evaluation and comparison metrics. Moreover, two well-regarded gradient descent algorithms including Back propagation (BP) and Levenberg Marquardt (LM) are utilized to validate the results obtained by evolutionary-based MLP trainers. It is observed that MLPs developed using MFO are the most robust ones among MLPs trained using other evolutionary and gradient descent algorithms.     

Cognitive effects of language on human navigation

Language has been linked to spatial representation and behavior in humans, but the nature of this effect is debated. Here, we test whether simple verbal expressions improve 4-year-old children’s performance in a disoriented search task in a small rectangular room with a single red landmark wall. Disoriented children’s landmark-guided search for a hidden object was dramatically enhanced when the experimenter used certain verbal expressions to designate the landmark during the hiding event. Both a spatial expression (“I’m hiding the sticker at the red/white wall”) and a non-spatial but task-relevant expression (“The red/white wall can help you get the sticker”) enhanced children’s search, relative to uncued controls. By contrast, a verbal expression that drew attention to the landmark in a task-irrelevant manner (“Look at this pretty red/white wall”) produced no such enhancement. These findings provide further evidence that language changes spatial behavior in children and illuminate one mechanism through which language exerts its effect: by helping children understand the relevance of landmarks for encoding locations.     

The role of mental rotations in primate-inspired robot navigation

Scripts store the temporal order of component events of everyday activities as well as the temporal position of the events within the activity (early or late). When confronted with an activity, predictions are generated about how the component events will unfold. Thereby, an error-detection mechanism continuously monitors whether they unfold as anticipated or not in order to reveal errors in the unfolding activity. We investigated whether the temporal position “early” or “late” influenced the detection of errors using the pupillary response as an index of cognitive resource consumption. An event triplet consisting of three events was presented in a chronological or non-chronological temporal order. Crucially, the triplet focused either on the beginning (temporal position “early”) or the end (temporal position “late”) of an activity. We assumed that these position codes would be used to facilitate error detection when a non-chronological event was presented. Results showed that errors in the temporal order were detected more successfully in early than in late triplets. Results further suggest that strong predictions are formed about how an activity begins. Violations of this prediction must be overcome by zooming into the representation and allocating attention to the temporal position that consumes cognitive resources. Only after zooming in has taken place successfully may the position codes be used to anticipate temporal violations in unfolding event sequences.     

The role of mental rotations in primate-inspired robot navigation

The use of a primate's spatial ability of mental rotation to serve as a basis for robotic navigation has been almost entirely overlooked by the robotics community to date. In this paper, the role of this cognitive capacity is presented as an adjunct to existing robotic control systems, with the underlying approach being derived from studies of primate spatial cognition. Specifically, optical flow is used as a basis for transitory representations (snapshots) that are compared to an a priori visual goal to provide corrective course action for a robot when moving through the world. The underlying architecture and procedures are described.     

Spatial complexity in children's language

The purpose of this research was to explore the properties of locative scenes which influence the sequence of the acquisition of spatial prepositions in English. Children ranging in age from about 2;8 to 5;6 were tested with a comprehension test involving a sentence-picture matching task. The comprehension test contained six kinds of spatial contrasts which were judged to vary in the geometric complexity of the scene. The order of acquisition was as follows: (1) into/out of & onto/off of, (2) in/on, (3) into/onto & out of/off of and through/over (around), (4) between X & Y/Y & Z, and (5) across/along. Complexity depends on a number of factors such as the number of referent objects and the nature of the relationship between the object to be located and the critical feature of the referent object. Prepositions which involve a more complex spatial geometry are more difficult for young children to comprehend. It was argued that the sequence of acquisition is partially determined by the course of conceptual development.     

The second me: Seeing the real body during humanoid robot embodiment produces an illusion of bi-location

Whole-body embodiment studies have shown that synchronized multi-sensory cues can trick a healthy human mind to perceive self-location outside the bodily borders, producing an illusion that resembles an out-of-body experience (OBE). But can a healthy mind also perceive the sense of self in more than one body at the same time? To answer this question, we created a novel artificial reduplication of one’s body using a humanoid robot embodiment system. We first enabled individuals to embody the humanoid robot by providing them with audio-visual feedback and control of the robot head movements and walk, and then explored the self-location and self-identification perceived by them when they observed themselves through the embodied robot. Our results reveal that, when individuals are exposed to the humanoid body reduplication, they experience an illusion that strongly resembles heautoscopy, suggesting that a healthy human mind is able to bi-locate in two different bodies simultaneously.     

Triggering social interactions: chimpanzees respond to imitation by a humanoid robot and request responses from it

Even the most rudimentary social cues may evoke affiliative responses in humans and promote social communication and cohesion. The present work tested whether such cues of an agent may also promote communicative interactions in a nonhuman primate species, by examining interaction-promoting behaviours in chimpanzees. Here, chimpanzees were tested during interactions with an interactive humanoid robot, which showed simple bodily movements and sent out calls. The results revealed that chimpanzees exhibited two types of interaction-promoting behaviours during relaxed or playful contexts. First, the chimpanzees showed prolonged active interest when they were imitated by the robot. Second, the subjects requested ‘social’ responses from the robot, i.e. by showing play invitations and offering toys or other objects. This study thus provides evidence that even rudimentary cues of a robotic agent may promote social interactions in chimpanzees, like in humans. Such simple and frequent social interactions most likely provided a foundation for sophisticated forms of affiliative communication to emerge.