Spatial Localization Task Research Articles

Domestic chickens solving mirror-mediated spatial location tasks uncovering their cognitive abilities

The increasing demand on adapting modern livestock farming to higher animal welfare standards requires a thorough understanding of a species’ cognitive abilities to determine their adaptability. With the chicken being the world’s most numerous birds in animal production, it is mandatory to identify its cognitive abilities and limitations in order to meet its needs. We investigated if chickens are able to use and understand the reflective properties of a mirror that is the correlation of reflections of food rewards and their real location. In total, 18 female chickens of two different breeds were tested in a mirror-mediated spatial location task. Eleven out of eighteen hens solved the task successfully and thus, possibly exploited the correlation between the reflection in the mirror and the real food reward. We found differences on a breed and on the individual level, with different amounts of time needed learning the association of reward and mirror image. The results imply sophisticated cognitive abilities in chickens, assuming they may be able to understand how mirror images represent objects in the real environment, and to make use of it during foraging. The chicken’s cognitive ability might lead to a new understanding and provision of animal welfare-compliant production environments.

Development and validation of a questionnaire for assessing visual and auditory spatial localization abilities in dual sensory impairment

Spatial localization is important for social interaction and safe mobility, and relies heavily on vision and hearing. While people with vision or hearing impairment compensate with their intact sense, people with dual sensory impairment (DSI) may require rehabilitation strategies that take both impairments into account. There is currently no tool for assessing the joint effect of vision and hearing impairment on spatial localization in this large and increasing population. To this end, we developed a novel Dual Sensory Spatial Localization Questionnaire (DS-SLQ) that consists of 35 everyday spatial localization tasks. The DS-SLQ asks participants about their difficulty completing different tasks using only vision or hearing, as well as the primary sense they rely on for each task. We administered the DS-SLQ to 104 participants with heterogenous vision and hearing status. Rasch analysis confirmed the psychometric validity of the DS-SLQ and the feasibility of comparing vision and hearing spatial abilities in a unified framework. Vision and hearing impairment were associated with decreased visual and auditory spatial abilities. Differences between vision and hearing abilities predicted overall sensory reliance patterns. In DSI rehabilitation, DS-SLQ may be useful for measuring vision and hearing spatial localization abilities and predicting the better sense for completing different spatial localization tasks.

Coercive mating has no impact on spatial learning, cognitive flexibility, and fecundity in female porthole livebearers (Poeciliopsis gracilis).

Coercive mating is a sexual selection strategy that is likely to influence female cognition. Female harassment levels have been linked to altered brain gene expression patterns and brain size evolution, suggesting females may respond to coercive mating by investing energy into "outsmarting" males. However, females exposed to coercive males have decreased foraging efficiency and likely increased stress levels, suggesting their brain function might instead be impaired. While it is therefore likely that coercive mating impacts female cognitive abilities, a direct test of this idea is currently lacking. In this study, we investigate the impact of coercive mating on female spatial memory and cognitive flexibility in a species with prevalent coercive mating. We compared the performance of female porthole livebearers (Poeciliopsis gracilis), which had been previously housed alone or with a coercive male, in both a spatial food localization task and a reversal learning task. While we found that both single and paired fish exhibited high proficiency in learning both tasks, we found no differences in learning ability between females that had or had not experienced coercive mating. In addition, our study found that the presence of a coercive male had no impact on female fecundity, but did influence female mass and standard length. Several studies have assumed that the presence of males, particularly coercive males, may affect the cognitive performance of female fish. However, our study shows that for some species females adapted to coercive mating regimes may be unaffected by male presence with regards to some cognitive tasks.

Autism-related traits are related to effectiveness of immersive visual guidance on spatial cognitive ability: a pilot study

A head-mounted display could potentially restrict users’ visual fields and thereby impair their spatial cognitive ability. Spatial cognition can be assisted with immersive visual guidance. However, whether this technique is useful for individuals with autism-spectrum disorder (ASD) remains unclear. Given the recent virtual reality (VR) contents targeting individuals with ASD, the relationship between ASD-related traits and the effectiveness of immersive visual guidance should be clarified. This pilot study evaluated how ASD-related traits (autistic traits and empathizing–systemizing cognitive styles) among typically developing individuals are related to the effectiveness of visual guidance. Participants performed visual search and spatial localization tasks while using immersive visual guidance. In the visual search task, participants searched immersive VR environments for a target object and pushed a button according to the target color as quickly as possible. In the localization task, they viewed immersive visual guidance for a short duration and localized the guided direction via a controller. Results showed that visual search times were hastened with systemizing cognition. However, ASD-related traits were not significantly related to localization accuracy. These findings suggest that immersive visual guidance is generally useful for individuals with higher ASD-related traits.

A common format for representing spatial location in visual and motor working memory.

Does the mind rely on similar systems of spatial representation for both perception and action? Here, we assessed the format of location representations in two simple spatial localization tasks. In one task, participants simply remembered the location of an item based solely on visual input. In another, participants remembered the location of a point in space based solely on kinesthetic input. Participants' recall errors were more consistent with the use of polar coordinates than Cartesian coordinates in both tasks. Moreover, measures of spatial bias and performance were correlated across modalities. In a subsequent study, we tested the flexibility with which people use polar coordinates to represent space; we show that the format in which the information is presented to participants influences how that information is encoded and the errors that are made as a result. We suggest that polar coordinates may be a common means of representing location information across visual and motor modalities, but that these representations are also flexible in form.

MultiTab: A Novel Portable Device to Evaluate Multisensory Skills.

To infer spatial-temporal features of an external event we are guided by multisensory cues, with intensive research showing an enhancement in the perception when information coming from different sensory modalities are integrated. In this scenario, the motor system seems to also have an important role in boosting perception. With the present work, we introduce and validate a novel portable technology, named MultiTab, which is able to provide auditory and visual stimulation, as well as to measure the user's manual responses. Our preliminary results indicate that MultiTab reliably induces multisensory integration in a spatial localization task, shown by significantly reduced manual response times in the localization of audiovisual stimuli compared to unisensory stimuliClinical relevance- The current work presents a novel portable device that could contribute to the clinical evaluation of multisensory processing as well as spatial perception. In addition, by promoting and recording manual actions, MultiTab could be especially suitable for the design of rehabilitative protocols using multisensory motor training.

Computational modeling of human multisensory spatial representation by a neural architecture.

Our brain constantly combines sensory information in unitary percept to build coherent representations of the environment. Even though this process could appear smooth, integrating sensory inputs from various sensory modalities must overcome several computational issues, such as recoding and statistical inferences problems. Following these assumptions, we developed a neural architecture replicating humans' ability to use audiovisual spatial representations. We considered the well-known ventriloquist illusion as a benchmark to evaluate its phenomenological plausibility. Our model closely replicated human perceptual behavior, proving a truthful approximation of the brain's ability to develop audiovisual spatial representations. Considering its ability to model audiovisual performance in a spatial localization task, we release our model in conjunction with the dataset we recorded for its validation. We believe it will be a powerful tool to model and better understand multisensory integration processes in experimental and rehabilitation environments.

Motor Influence in Developing Auditory Spatial Cognition in Hemiplegic Children with and without Visual Field Disorder.

Spatial representation is a crucial skill for everyday interaction with the environment. Different factors seem to influence spatial perception, such as body movements and vision. However, it is still unknown if motor impairment affects the building of simple spatial perception. To investigate this point, we tested hemiplegic children with (HV) and without visual field (H) disorders in an auditory and visual-spatial localization and pitch discrimination task. Fifteen hemiplegic children (nine H and six HV) and twenty with typical development took part in the experiment. The tasks consisted in listening to a sound coming from a series of speakers positioned at the front or back of the subject. In one condition, subjects were asked to discriminate the pitch, while in the other, subjects had to localize the position of the sound. We also replicated the spatial task in a visual modality. Both groups of hemiplegic children performed worse in the auditory spatial localization task compared with the control, while no difference was found in the pitch discrimination task. For the visual-spatial localization task, only HV children differed from the two other groups. These results suggest that movement is important for the development of auditory spatial representation.

Grave errors: Exploring the influence of motion mechanics on learning outcomes in a virtual cemetery.

Systematic research examining affordances such as navigability are important for understanding how to design virtual learning environments. To explore this, a fully immersive virtual cemetery modeled after fictitious Spoon River Anthology was created to assess how motion mechanics related to participant navigability would influence learning outcomes. A 2 × 2, fully crossed, between-subjects (N = 116) experiment manipulating navigation type (natural walking vs. teleportation) and type of piloting (proximal vs. distal orientations) was tested. Participants used the Oculus Rift S virtual reality (VR) headset with a portable backpack, allowing unimpeded movement to complete the study. Results demonstrated that the type of navigation and piloting orientation differentially influenced learning performance. Specifically, an interaction effect occurred where participants in the natural walking with a distal orientation condition showed significantly higher scores on narrative testing, spatial location, and spatial reconstruction tasks, when compared to the teleportation with distal orientation condition. Implications for how these findings may be used in VR environments where the prime objective is learning are discussed.

Morphology and unbiased stereology of the lateral superior olive in the short-beaked common dolphin, Delphinus delphis (Cetacea, Delphinidae).

In all mammals, the superior olivary complex (SOC) comprises a group of auditory brainstem nuclei that are important for sound localization. Its principal nuclei, the lateral superior olive (LSO) and the medial superior olive (MSO) process interaural time and intensity differences, which are the main cues for sound localization in the horizontal plane. Toothed whales (odontocetes) rely heavily on hearing and echolocation for foraging, orientation, and communication and localize sound with great acuity. The investigation of the SOC in odontocetes provides insight into adaptations to underwater hearing and echolocation. However, quantitative anatomical data for odontocetes are currently lacking. We quantified the volume, total neuron number, and neuron density of the LSO of six common dolphins (Delphinus delphis) using the Cavalieri principle and the unbiased stereology optical fractionator. Our results show that the LSO in D. delphis has a volume of 150 + (SD=27) mm3 , which is on average 69 (SEM=19) times larger than the LSO in human, or 37 (SEM=11) times larger than the human LSO and MSO combined. The LSO of D. delphis contains 20,876 ± (SD=3300) neurons. In comparison, data reported for the human brainstem indicate the LSO has only about ¼ that number but about the same number for the LSO and MSO combined (21,100). LSO neurons range from 21 to 25 μm (minor axis) and from 44 to 61 μm (major axis) in transverse sections. The LSO neuron packing density is 1080 ± (SD=204) neurons/mm3 , roughly half of the LSO neuron density in human. SMI-32-immunohistochemistry was used to visualize projection neurons in the LSO and revealed the presence of principal, marginal, and multipolar neurons in transverse sections. The distinct morphology of the LSO likely reflects the common dolphin's superb sensitivity to ultra-high frequencies and ability to detect and analyze sounds and their location as part of its underwater spatial localization and echolocation tasks.

Visual space orientation and representational gravity: Contextual orientation visual cues modulate the perceptual extrapolation of motion.

The perceived offset of a moving target is usually displaced forward, in the direction of motion (representational momentum), and downward, in the direction of gravity (representational gravity). In what refers to the latter, the meaning of "downward in the direction of gravity" is ill-defined, for it is known that the perceived direction of gravity ("downward") results from the interaction of vestibular signals, sensitive to the gravito-inertial vector, an aprioristic tendency to assume that it aligns with the body's main axis (idiotropic vector) and visual cues. The present work aims to disclose what effects visual cues have on representational gravity. Participants performed a spatial localization task as well as a subjective visual vertical (SVV) and an oriented character recognition task (OCHART), with stimuli superimposed on a realistic background either aligned with earth's vertical or tilted rightward or leftward. Outcomes disclosed significant and lawful effects of the orientation of the visual context on spatial localization judgements. Specifically, forward displacement along the target's motion direction was bigger for targets moving along the "horizontal" direction implied by the background scene. These trends were furthermore found to be correlated, at an individual level, with the magnitude of SVV, but not with the perceptual upright (as measured with OCHART). These findings show that features of the spatial localization judgements specifically index the visually induced spatial orientation, thus offering the prospect to expand available tools for inquiries concerning human spatial orientation, besides clarifying the multisensorial nature and significantly expanding the notion of representational gravity. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Effects of Audiovisual Presentations on Visual Localization Errors: One or Several MultisensoryMechanisms?

The present study examines the extent to which temporal and spatial properties of sound modulate visual motion processing in spatial localization tasks. Participants were asked to locate the place at which a moving visual target unexpectedly vanished. Across different tasks, accompanying sounds were factorially varied within subjects as to their onset and offset times and/or positions relative to visual motion. Sound onset had no effect on the localization error. Sound offset was shown to modulate the perceived visual offset location, both for temporal and spatial disparities. This modulation did not conform to attraction toward the timing or location of the sounds but, demonstrably in the case of temporal disparities, to bimodal enhancement instead. Favorable indications to a contextual effect of audiovisual presentations on interspersed visual-only trials were also found. The short sound-leading offset asynchrony had equivalent benefits to audiovisual offset synchrony, suggestive of the involvement of early-level mechanisms, constrained by a temporal window, at these conditions. Yet, we tentatively hypothesize that the whole of the results and how they compare with previous studies requires the contribution of additional mechanisms, including learning-detection of auditory-visual associations and cross-sensory spread of endogenous attention.

Bayesian transfer in a complex spatial localization task.

Prior knowledge can help observers in various situations. Adults can simultaneously learn two location priors and integrate these with sensory information to locate hidden objects. Importantly, observers weight prior and sensory (likelihood) information differently depending on their respective reliabilities, in line with principles of Bayesian inference. Yet, there is limited evidence that observers actually perform Bayesian inference, rather than a heuristic, such as forming a look-up table. To distinguish these possibilities, we ask whether previously learned priors will be immediately integrated with a new, untrained likelihood. If observers use Bayesian principles, they should immediately put less weight on the new, less reliable, likelihood (“Bayesian transfer”). In an initial experiment, observers estimated the position of a hidden target, drawn from one of two distinct distributions, using sensory and prior information. The sensory cue consisted of dots drawn from a Gaussian distribution centered on the true location with either low, medium, or high variance; the latter introduced after block three of five to test for evidence of Bayesian transfer. Observers did not weight the cue (relative to the prior) significantly less in the high compared to medium variance condition, counter to Bayesian predictions. However, when explicitly informed of the different prior variabilities, observers placed less weight on the new high variance likelihood (“Bayesian transfer”), yet, substantially diverged from ideal. Much of this divergence can be captured by a model that weights sensory information, according only to internal noise in using the cue. These results emphasize the limits of Bayesian models in complex tasks.

Multisensory Integration Develops Prior to Crossmodal Recalibration.

It has been hypothesized that crossmodal recalibration plays a crucial role for the development of multisensory integration capabilities [1]. To test the developmental trajectory of multisensory integration and crossmodal recalibration, we used a combined ventriloquist/ventriloquist aftereffect paradigm [2] in children aged 5-9 years. The ventriloquist effect (indicating multisensory integration), that is, the shift of auditory localization toward simultaneously presented but spatially discrepant visual stimuli, was larger in children than in adults, which was attributed to a lower auditory localization precision in the children. In fact, the size of the ventriloquist effect depended on the visual stimulus reliability in both children and adults. In all groups, the ventriloquist effect was best explained by a causal inference model. In contrast to their multisensory integration capabilities, 5-year-old children did not recalibrate. The immediate ventriloquist aftereffect (indicating recalibration after a single exposure to a spatially discrepant audio-visual stimulus) emerged in 6- to 7-year-old children, whereas the cumulative ventriloquist aftereffect (reflecting recalibration to the audio-visual spatial discrepancies over the complete experiment) was not observed before the age of 8 years. First, in contrast to common beliefs, the present results provide evidence that multisensory integration precedes rather than follows crossmodal recalibration during development. Second, we report developmental evidence for a dissociation of the processes involved in multisensory integration and immediate as well as cumulative recalibration. We speculate that multisensory integration is a prerequisite for crossmodal recalibration, because the multisensory percept, rather than unimodal cues, might comprise a crucial signal for the calibration of the sensory systems.

Tracking the completion of parts into whole objects: Retinotopic activation in response to illusory figures in the lateral occipital complex

Illusory figures demonstrate the visual system’s ability to integrate separate parts into coherent, whole objects. The present study was performed to track the neuronal object construction process in human observers, by incrementally manipulating the grouping strength within a given configuration until the emergence of a whole-object representation. Two tasks were employed: First, in the spatial localization task, object completion could facilitate performance and was task-relevant, whereas it was irrelevant in the second, luminance discrimination task. Concurrent functional magnetic resonance imaging (fMRI) used spatial localizers to locate brain regions representing task-critical illusory-figure parts to investigate whether the step-wise object construction process would modulate neural activity in these localized brain regions. The results revealed that both V1 and the lateral occipital complex (LOC, with sub-regions LO1 and LO2) were involved in Kanizsa figure processing. However, completion-specific activations were found predominantly in LOC, where neural activity exhibited a modulation in accord with the configuration’s grouping strength, whether or not the configuration was relevant to performing the task at hand. Moreover, right LOC activations were confined to LO2 and responded primarily to surface and shape completions, whereas left LOC exhibited activations in both LO1 and LO2 and was related to encoding shape structures with more detail. Together, these results demonstrate that various grouping properties within a visual scene are integrated automatically in LOC, with sub-regions located in different hemispheres specializing in the component sub-processes that render completed objects.

The role of cortical areas hMT/V5+ and TPJ on the magnitude of representational momentum and representational gravity: a transcranial magnetic stimulation study.

The perceived vanishing location of a moving target is systematically displaced forward, in the direction of motion-representational momentum-, and downward, in the direction of gravity-representational gravity. Despite a wealth of research on the factors that modulate these phenomena, little is known regarding their neurophysiological substrates. The present experiment aims to explore which role is played by cortical areas hMT/V5+, linked to the processing of visual motion, and TPJ, thought to support the functioning of an internal model of gravity, in modulating both effects. Participants were required to perform a standard spatial localization task while the activity of the right hMT/V5+ or TPJ sites was selectively disrupted with an offline continuous theta-burst stimulation (cTBS) protocol, interspersed with control blocks with no stimulation. Eye movements were recorded during all spatial localizations. Results revealed an increase in representational gravity contingent on the disruption of the activity of hMT/V5+ and, conversely, some evidence suggested a bigger representational momentum when TPJ was stimulated. Furthermore, stimulation of hMT/V5+ led to a decreased ocular overshoot and to a time-dependent downward drift of gaze location. These outcomes suggest that a reciprocal balance between perceived kinematics and anticipated dynamics might modulate these spatial localization responses, compatible with a push-pull mechanism.

Low-dose cone-beam CT via raw counts domain low-signal correction schemes: Performance assessment and task-based parameter optimization (Part II. Task-based parameter optimization).

Different low-signal correction (LSC) methods have been shown to efficiently reduce noise streaks and noise level in CT to provide acceptable images at low-radiation dose levels. These methods usually result in CT images with highly shift-variant and anisotropic spatial resolution and noise, which makes the parameter optimization process highly nontrivial. The purpose of this work was to develop a local task-based parameter optimization framework for LSC methods. Two well-known LSC methods, the adaptive trimmed mean (ATM) filter and the anisotropic diffusion (AD) filter, were used as examples to demonstrate how to use the task-based framework to optimize filter parameter selection. Two parameters, denoted by the set P, for each LSC method were included in the optimization problem. For the ATM filter, these parameters are the low- and high-signal threshold levels pl and ph ; for the AD filter, the parameters are the exponents δ and γ in the brightness gradient function. The detectability index d' under the non-prewhitening (NPW) mathematical observer model was selected as the metric for parameter optimization. The optimization problem was formulated as an unconstrained optimization problem that consisted of maximizing an objective function d'(P), where i and j correspond to the i-th imaging task and j-th spatial location, respectively. Since there is no explicit mathematical function to describe the dependence of d' on the set of parameters P for each LSC method, the optimization problem was solved via an experimentally measured d' map over a densely sampled parameter space. In this work, three high-contrast-high-frequency discrimination imaging tasks were defined to explore the parameter space of each of the LSC methods: a vertical bar pattern (task I), a horizontal bar pattern (task II), and a multidirectional feature (task III). Two spatial locations were considered for the analysis, a posterior region-of-interest (ROI) located within the noise streaks region and an anterior ROI, located further from the noise streaks region. Optimal results derived from the task-based detectability index metric were compared to other operating points in the parameter space with different noise and spatial resolution trade-offs. The optimal operating points determined through the d' metric depended on the interplay between the major spatial frequency components of each imaging task and the highly shift-variant and anisotropic noise and spatial resolution properties associated with each operating point in the LSC parameter space. This interplay influenced imaging performance the most when the major spatial frequency component of a given imaging task coincided with the direction of spatial resolution loss or with the dominant noise spatial frequency component; this was the case of imaging task II. The performance of imaging tasks I and III was influenced by this interplay in a smaller scale than imaging task II, since the major frequency component of task I was perpendicular to imaging task II, and because imaging task III did not have strong directional dependence. For both LSC methods, there was a strong dependence of the overall d' magnitude and shape of the contours on the spatial location within the phantom, particularly for imaging tasks II and III. The d' value obtained at the optimal operating point for each spatial location and imaging task was similar when comparing the LSC methods studied in this work. A local task-based detectability framework to optimize the selection of parameters for LSC methods was developed. The framework takes into account the potential shift-variant and anisotropic spatial resolution and noise properties to maximize the imaging performance of the CT system. Optimal parameters for a given LSC method depend strongly on the spatial location within the image object.

Recalibrating the body: visuotactile ventriloquism aftereffect.

Visuotactile ventriloquism is a recently reported effect showing that somatotopic tactile representations (namely, representation of location along the surface of one’s arm) can be biased by simultaneous presentation of a visual stimulus in a spatial localization task along the surface of the skin. Here we investigated whether the exposure to discrepancy between tactile and visual stimuli on the skin can induce lasting changes in the somatotopic representations of space. We conducted an experiment investigating this question by asking participants to perform a localization task that included unisensory and bisensory trials, before and after exposure to spatially discrepant visuotactile stimuli. Participants localized brief flashes of light and brief vibrations that were presented along the surface of their forearms, and were presented either individually (unisensory conditions) or were presented simultaneously at the same location or different locations. We then compared the localization of tactile stimuli in unisensory tactile conditions before and after the exposure to discrepant bisensory stimuli. After exposure, participants exhibited a shift in their tactile localizations in the direction of the visual stimulus that was presented during the exposure block. These results demonstrate that the somatotopic spatial representations are capable of rapidly recalibrating after a very brief exposure to visually discrepant stimuli.

A biologically inspired neurocomputational model for audiovisual integration and causal inference.

Recently, experimental and theoretical research has focused on the brain's abilities to extract information from a noisy sensory environment and how cross-modal inputs are processed to solve the causal inference problem to provide the best estimate of external events. Despite the empirical evidence suggesting that the nervous system uses a statistically optimal and probabilistic approach in addressing these problems, little is known about the brain's architecture needed to implement these computations. The aim of this work was to realize a mathematical model, based on physiologically plausible hypotheses, to analyze the neural mechanisms underlying multisensory perception and causal inference. The model consists of three layers topologically organized: two encode auditory and visual stimuli, separately, and are reciprocally connected via excitatory synapses and send excitatory connections to the third downstream layer. This synaptic organization realizes two mechanisms of cross-modal interactions: the first is responsible for the sensory representation of the external stimuli, while the second solves the causal inference problem. We tested the network by comparing its results to behavioral data reported in the literature. Among others, the network can account for the ventriloquism illusion, the pattern of sensory bias and the percept of unity as a function of the spatial auditory-visual distance, and the dependence of the auditory error on the causal inference. Finally, simulations results are consistent with probability matching as the perceptual strategy used in auditory-visual spatial localization tasks, agreeing with the behavioral data. The model makes untested predictions that can be investigated in future behavioral experiments.

Spatial localization of sound elicits early responses from occipital visual cortex in humans

Much evidence points to an interaction between vision and audition at early cortical sites. However, the functional role of these interactions is not yet understood. Here we show an early response of the occipital cortex to sound that it is strongly linked to the spatial localization task performed by the observer. The early occipital response to a sound, usually absent, increased by more than 10-fold when presented during a space localization task, but not during a time localization task. The response amplification was not only specific to the task, but surprisingly also to the position of the stimulus in the two hemifields. We suggest that early occipital processing of sound is linked to the construction of an audio spatial map that may utilize the visual map of the occipital cortex.