Visuospatial Representations Research Articles

Watching hands move enhances learning from concrete and dynamic visualizations.

This article explores the role of sensorimotor engagement in students' learning of a challenging science, technology, engineering, and math-related concept. Previous research has failed to distinguish two features commonly associated with embodiment: sensorimotor engagement and visuospatial concreteness. In the current research, we ask whether sensorimotor engagement-operationalized as watching a video of hands manipulating paper representations-offers unique benefits beyond the visuospatial concreteness of a dynamic visualization of the same process. Participants were randomly assigned to one of three conditions to learn about the shuffle() function in R: a Watch Hands Moving Objects group, which watched a video with hands; a Watch Moving Objects group, which watched a video with a dynamic visualization in which objects moved without hands; or a control group, which watched a live-coding video that did not include either hands or visuospatial representations. Results revealed that only participants in the Watch Hands Moving Objects group demonstrated significantly superior performance compared with both the Watch Moving Objects group and control groups. These findings highlight the unique benefit of sensorimotor engagement for learning, contributing to a deeper understanding of how embodiment can enhance the learning process. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Vertical prism adaptation, but not sound presentation, modulates the visuospatial representation: A manual line-bisection study

The present study aimed at testing whether vertical prism adaptation (PA) can modulate vertical visuospatial representation, assessed with a vertical manual line-bisection (MLB) task (Experiment 1). In a second time, we wanted to investigate the potential influence of sound presentation during such a task. Sound is a spatially valued element that has previously been reported to modify horizontal visuospatial representation. In Experiment 2, we presented either a high pitch, a low pitch, or no sound during the same MLB as in Experiment 1. With this experiment, we also searched for an eventual interaction between the effect of sound presentation and the potential cognitive aftereffects of vertical PA on visual representation.Both Experiments 1 and 2 were constructed with the same design and conducted with two distinct groups of young healthy right-handed participants. First, we assessed the initial sensorimotor state with an open-loop pointing task, and the initial representational state through a vertical MLB (with addition of sound for Experiment 2). Then participants were submitted to a 16-minute PA procedure and were tested again on the open-loop pointing task and the MLB to assess the aftereffects following prism removal.Our results showed sensorimotor aftereffects following both upward and downward PA, in a direction opposed to the optical deviation used. The early aftereffects measured following PA were symmetrical, but at the end of the experiment the residual aftereffects were smaller following downward PA than upward PA. We also provide a new insight on the aftereffects of vertical PA on visuospatial representation, showing that downward PA (but not upward PA) can produce an upward bias on the manual line-bisection task. This is the first proof of such cognitive aftereffects following vertical PA. However, we found no effect of sound presentation on the vertical visual space representation and no interaction between PA and sound presentation.

What Is a Visual Stream?

The dual stream model of the human and non-human primate visual systems remains Leslie Ungerleider's (1946-2020) most indelible contribution to visual neuroscience. In this model, a dorsal "where" stream specialized for visuospatial representation extends through occipitoparietal cortex, whereas a ventral "what" stream specialized for representing object qualities extends through occipito-temporal cortex. Over time, this model underwent a number of revisions and expansions. In one of her last scientific contributions, Leslie proposed a third visual stream specialized for representing dynamic signals related to social perception. This alteration invites the question: What is a visual stream, and how are different visual streams individuated? In this article, we first consider and reject a simple answer to this question based on a common idealizing visualization of the model, which conflicts with the complexities of the visual system that the model was intended to capture. Next, we propose a taxonomic answer that takes inspiration from the philosophy of science and Leslie's body of work, which distinguishes between neural mechanisms, pathways, and streams. In this taxonomy, visual streams are superordinate to pathways and mechanisms and provide individuation conditions for determining whether collections of cortical connections delineate different visual streams. Given this characterization, we suggest that the proposed third visual stream does not yet meet these conditions, although the tripartite model still suggests important revisions to how we think about the organization of the human and non-human primate visual systems.

What makes different number-space mappings interact?

Models of numerical cognition consider a visuo-spatial representation to be at the core of numerical processing, the 'mental number line'. Two main interference effects between number and space have been described: the SNARC effect reflects a small number/left side and large number/right side association (number-location mapping); the size-congruity effect (SCE) reflects a small number/small size and large number/large size association (number-size mapping). Critically, a thorough investigation on the representational source for these two number-space mappings is lacking, leaving open the question of whether the same representation underlies both phenomena. Here, we build on a recent study (Viarouge and de Hevia in Front Hum Neurosci 15:750964, 2021) in order to address this question in three experiments, by systematically manipulating the presence of the two conditions that might elicit an interaction between SNARC and SCE: (i) an implicit task whereby numerical and spatial information are task-irrelevant, (ii) a design in which the number-space congruency relative to both mappings vary at the same level -either both within or between blocks. Experiment 1 replicated the interaction between the two mappings when both factors were present. Experiments 2 and 3 dissociated the two factors by varying the two mappings at the same level but using an explicit comparison task (Experiment 2), or by using an implicit task but with mappings varying at different levels (Experiment 3). We found that both factors, either in combination or used in isolation, drive the interaction between the two number-space mappings. These findings are discussed in terms of the weight given to each mapping, suggesting that a single representation encompassing both number-space mappings is therefore activated whenever both mappings are given equal weight through task requirements.

Sonic Sleight of Hand: Sound Induces Illusory Distortions in the Perception and Prediction of Robot Action

AbstractFor efficient human–robot interaction, human operators need to be able to efficiently represent the robot’s movements in space and predict its next steps. However, according to frameworks of Bayesian multisensory integration, features outside the motion itself—like the sounds a robot makes while it moves—should affect how otherwise identical motions are perceived. Here, we translate an established psychophysical task from experimental psychology to a human–robot interaction context, which can measure these distortions to motion perception. In two series of preregistered studies, participants watched a humanoid robot make forward and backward reaching movements. When the robot hand suddenly disappeared, they reported its last seen location, either with the mouse cursor (Experiment 1a and 1b) or by matching it to probe stimuli in different locations (Experiment 2a and 2b). The results revealed that even small changes to the robot’s sound robustly affect participants’ visuospatial representation of its motions, so that the motion appeared to extend further in space when accompanied by slightly (100 ms) longer sounds compared to slightly shorter sounds (100 ms shorter). Moreover, these sound changes do not only affect where people currently locate the robot’s motion, but where they anticipate its future steps. These findings show that sound design is an effective medium for manipulating how people represent otherwise identical robot actions and coordinate its interactions with it. The study acts as proof of concept that psychophysical tasks provide a promising tool to measure how design parameters influence the perception and prediction of robot motion.

Structured visuospatial representations revealed through serial reproduction.

Working memory is a reconstructive process that requires integrating multiple hierarchical representations of objects. This hierarchical reconstruction allows us to overcome perceptual uncertainty and limited cognitive capacity but yields systematic biases in working memory as individual items are influenced by the ensemble statistics of the scene, or of their particular group. Given the importance of the hierarchical encoding of a display, we aim to characterize what structures people use to encode visual scenes using a nonparametric data-driven approach. In Experiment 1, we examine visuospatial memory for locations by asking participants to recall the locations of objects in a serial reproduction task. We show that people report items in a more compact structure than they initially were and organize them into clustered spatial groups. In Experiment 2, we explicitly introduce discrete color groups, allowing us to test whether the color feature governs the spatial grouping. We find that the spatial structures were color-contingent. By analyzing color groups, we circumvent the grouping uncertainty in Experiment 1 and further reveal that people compress color groups into collinear structures with similar orientations and equidistant spacing. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Age differences in effectiveness of encoding techniques on memory

ABSTRACT We compared the effectiveness of different encoding techniques across the adult age range. Three hundred participants: 100 younger, 100 middle-aged, and 100 older adults, were asked to encode a set of visually presented concrete and abstract words. Participants were shown target words one at a time, along with prompts (randomly and intermixed, within-subject) to either silently read, read aloud, write, or draw a picture of the target, for a duration of 10-seconds each. On a later free recall test, participants were given 2-minutes to type all the words they could remember from the encoding phase. Across age groups, we showed that drawing, writing, and reading aloud as encoding techniques yielded better memory than silently reading words, with drawing leading to the largest boost. While memory performance did decrease as age increased, it interacted with the encoding technique. Of note, there were no differences in memory performance in middle-aged compared to young adults. Importantly, age differences in memory emerged only when drawing was used as the encoding strategy, in line with previously reported age-related deficits in generating imagery, or integrating it with motoric processes. Despite this, concrete relative to abstract words that were drawn or written during encoding were better retained, regardless of age, suggesting these techniques facilitate formation of age-invariant visuo-spatial representations. Our findings suggest that whether age differences in memory emerge depends on the strategy used at encoding, and the type of information being encoded.

Visuospatial Cognitive Dysfunction in Patients with Vestibular Loss.

To characterize visuospatial and nonvisuospatial cognitive domains affected by vestibular loss and determine whether patient-reported outcomes measures (PROMs) correlate with performance on neuropsychological tests. Cross-sectional study. University-based tertiary medical center. Sixty-nine age-matched subjects: 25 patients with bilateral vestibular loss (BVL), 14 patients with unilateral vestibular loss (UVL), and 30 normal controls (NC). Neuropsychological tests used to assess visuospatial and auditory short-term and working memory, number magnitude representation, executive function, and attention. Validated PROMs used to evaluate quality of life and subjective cognitive impairment. Performance on neuropsychological tests and scores on PROM surveys. BVL and UVL patients performed significantly worse than NC subjects on tasks requiring visuospatial representation compared with NC subjects ( p < 0.01). BVL patients demonstrated decreased performance on spatial representation tasks compared with UVL and NC subjects ( p < 0.05 and p < 0.05, respectively). All subject groups performed similarly on tasks assessing nonvisuospatial cognitive domains, such as auditory short-term and working memory, executive function, and attention. PROMs did not seem to correlate with performance on neuropsychological tasks. Patients with vestibular loss exhibit impairments in tasks requiring visuospatial representation but perform similarly to NC subjects in tasks of auditory working memory, executive function, or attention. Currently available questionnaires may be insufficient to screen patients for cognitive deficits.

Stable Working Memory and Perceptual Representations in Macaque Lateral Prefrontal Cortex during Naturalistic Vision.

Primates use perceptual and mnemonic visuospatial representations to perform everyday functions. Neurons in the lateral prefrontal cortex (LPFC) have been shown to encode both of these representations during tasks where eye movements are strictly controlled and visual stimuli are reduced in complexity. This raises the question of whether perceptual and mnemonic representations encoded by LPFC neurons remain robust during naturalistic vision-in the presence of a rich visual scenery and during eye movements. Here we investigate this issue by training macaque monkeys to perform working memory and perception tasks in a visually complex virtual environment that requires navigation using a joystick and allows for free visual exploration of the scene. We recorded the activity of 3950 neurons in the LPFC (areas 8a and 9/46) of two male rhesus macaques using multielectrode arrays, and measured eye movements using video tracking. We found that navigation trajectories to target locations and eye movement behavior differed between the perception and working memory tasks, suggesting that animals used different behavioral strategies. Single neurons were tuned to target location during cue encoding and working memory delay, and neural ensemble activity was predictive of the behavior of the animals. Neural decoding of the target location was stable throughout the working memory delay epoch. However, neural representations of similar target locations differed between the working memory and perception tasks. These findings indicate that during naturalistic vision, LPFC neurons maintain robust and distinct neural codes for mnemonic and perceptual visuospatial representations.SIGNIFICANCE STATEMENT We show that lateral prefrontal cortex neurons encode working memory and perceptual representations during a naturalistic task set in a virtual environment. We show that despite eye movement and complex visual input, neurons maintain robust working memory representations of space, which are distinct from neuronal representations for perception. We further provide novel insight into the use of virtual environments to construct behavioral tasks for electrophysiological experiments.

Dynamic changes in spatial representation within the posterior parietal cortex in response to visuomotor adaptation.

Recent studies used functional magnetic resonance imaging (fMRI)population receptive field (pRF) mapping to demonstrate that retinotopic organization extends from the primary visual cortex to ventral and dorsal visual pathways, by quantifying visual field maps, receptive field size, and laterality throughout multiple areas. Visuospatial representation in the posterior parietal cortex (PPC) is modulated by attentional deployment, raising the question of whether spatial representation in the PPC is dynamic and flexible, and whether this flexibility contributes to visuospatial learning. To answer this question, changes in spatial representation within the PPC and early visual cortex were recorded with pRF mapping before and after prism adaptation (PA)-a well-established visuomotor technique that modulates visuospatial attention according to the direction of the visual displacement. As predicted, results showed that adaptation to left-shifting prisms increases pRF size in left PPC, while leaving space representation in the early visual cortex unchanged. This is the first evidence that PA drives a dynamic reorganization of response profiles in the PPC. These findings show that spatial representations in the PPC not only reflect changes driven by attentional deployment but dynamically change in response to modulation of external factors such as manipulation of the visuospatial input during visuomotor adaptation.

Backward recall and foreknowledge of recall direction: a test of the Encoding–Retrieval Matching Hypothesis

ABSTRACT When participants must recall a sequence of items in reverse order just after their presentation, inconsistent findings have been observed relative to when participants must recall a sequence in their presentation order. Recently, the Encoding–Retrieval Matching Hypothesis (ERM) has been developed to account for these inconsistencies. Within the ERM hypothesis, foreknowledge of recall direction plays an important role. In two experiments, we tested a key prediction of the ERM hypothesis: In backward recall with foreknowledge of recall direction, the size of the effect will vary as a function of its reliance on visuospatial representations. Participants performed an immediate serial recall task with digits. As predicted, the detrimental effect of manual–spatial tapping was larger in backward recall relative to forward recall when recall direction was predictable (Experiment 1b), but not when it was unpredictable (Experiment 1a). In Experiment 2, the word length effect, not relying on visuospatial representations, was equally large in forward and backward recall, and it was unaffected by foreknowledge of recall direction. Overall, the results support the predictions derived from the ERM hypothesis and contribute to the delineation of when and how foreknowledge can influence backward recall performance relative to forward recall performance.

Impaired body-centred sensorimotor transformations in congenitally deaf people.

Congenital deafness modifies an individual’s daily interaction with the environment and alters the fundamental perception of the external world. How congenital deafness shapes the interface between the internal and external worlds remains poorly understood. To interact efficiently with the external world, visuospatial representations of external target objects need to be effectively transformed into sensorimotor representations with reference to the body. Here, we tested the hypothesis that egocentric body-centred sensorimotor transformation is impaired in congenital deafness. Consistent with this hypothesis, we found that congenital deafness induced impairments in egocentric judgements, associating the external objects with the internal body. These impairments were due to deficient body-centred sensorimotor transformation per se, rather than the reduced fidelity of the visuospatial representations of the egocentric positions. At the neural level, we first replicated the previously well-documented critical involvement of the frontoparietal network in egocentric processing, in both congenitally deaf participants and hearing controls. However, both the strength of neural activity and the intra-network connectivity within the frontoparietal network alone could not account for egocentric performance variance. Instead, the inter-network connectivity between the task-positive frontoparietal network and the task-negative default-mode network was significantly correlated with egocentric performance: the more cross-talking between them, the worse the egocentric judgement. Accordingly, the impaired egocentric performance in the deaf group was related to increased inter-network connectivity between the frontoparietal network and the default-mode network and decreased intra-network connectivity within the default-mode network. The altered neural network dynamics in congenital deafness were observed for both evoked neural activity during egocentric processing and intrinsic neural activity during rest. Our findings thus not only demonstrate the optimal network configurations between the task-positive and -negative neural networks underlying coherent body-centred sensorimotor transformations but also unravel a critical cause (i.e. impaired body-centred sensorimotor transformation) of a variety of hitherto unexplained difficulties in sensory-guided movements the deaf population experiences in their daily life.

Visuomanual Vertical Prism Adaptation: Aftereffects on Visuospatial and Auditory Frequency Representations.

Sensorimotor aftereffects have been widely studied after lateral prism adaptation but not after vertical prism adaptation. It is thus well-known that lateral prism adaptation produces aftereffects on visuospatial representation and, recently, on auditory perception. This study aimed to explore the sensorimotor after-effects of vertical prism adaptation as well as its aftereffects on vertical visuospatial representation (Experiment 1) and on auditory frequency representation (Experiment 2). The experimental procedure was similar in both experiments: before and after prism adaptation to an upward or a downward optical deviation, healthy young participants performed an visual open-loop pointing task and a visual (Experiment 1) or an auditory (Experiment 2) perceptual bisection task. In the visual task, the participants had to indicate if they perceived the bisection as higher or lower than the true center of a line. In the auditory task, the participants had to indicate if they perceived the target auditory frequency closer to the low or the high limit of an auditory interval. For sensorimotor aftereffects, pointing errors were computed by means of a vertical touchscreen. For the perceptual bisection task, we measured the percentage of “down” (Experiment 1) or “low” responses (Experiment 2), and we computed the visual (Experiment 1) or the auditory (Experiment 2) subjective center for each participant. Statistical analyses were carried out separately for each optical deviation in each experiment. Sensorimotor aftereffects were observed in both experiments, in the opposite direction to the optical deviation (all ps < 0.01). No significant aftereffects occurred on visuospatial representation (all ps > 0.5), whereas the percentage of “low” responses and the auditory subjective center significantly increased after adaptation to a downward optical deviation (all ps < 0.05). Unlike lateral prism adaptation aftereffects that have been previously shown in both visuospatial horizontal representation and auditory frequency representation, aftereffects of vertical prism adaptation occurred in the auditory frequency representation but not in the vertical visuospatial representation. These results suggest that both vertical and lateral prism adaptations share a common substrate dedicated to the auditory modality (probably the temporal cortex), and that vertical adaptation does not act on the neural substrate of vertical visuospatial representation.

Are emojis processed visuo-spatially or verbally? Evidence for dual codes

ABSTRACT While some argue that emojis are processed like words, opponents note dissimilarities. We used a divided attention (DA) technique to examine whether memory for emojis, relative to words, engages primarily verbal or visuo-spatial cognitive representations. We compared the decline in memory output experienced when participants freely recalled a list of studied words or emojis under dual-task conditions with a concurrently performed distracting task. Participants encoded either words or emojis (between-subjects) under full attention (FA), and later recalled them under FA or while concurrently performing a 1-back task to words (DA Words), emojis (DA Emojis), or stars (DA Stars), manipulated within-subject. Emoji memory was higher overall compared to words. Word recall was unaffected by the DA Stars condition, but significantly worse in the DA Words-and to a lesser degree DA Emojis-condition, relative to FA. Results suggest that memory for words relies primarily on reactivation of verbal representations, which is hampered when the distracting task also requires verbal, but not visuo-spatial, processing. In contrast, small but significant declines in recall were observed for emojis across all DA conditions relative to FA. Results suggest that unlike words, representing and retrieving emojis engages both verbal and visuo-spatial processing.

No transfer effect of a fraction number line game on fraction understanding or fraction arithmetic: A randomized controlled trial

Fractions are hard to understand for students. According to Siegler’s integrated theory, magnitude understanding is central to numerical development. Whole-number magnitude understanding can be improved by serious games that include practicing mapping numbers onto number lines or similar one-dimensional visuospatial representations. These games were effective even when they did not include direct instruction on whole numbers. Previous studies have also evaluated whether similar number line estimation (NLE) interventions improve fraction learning. We contribute to this literature by evaluating how the catch-the-monster game with fractions affects NLE, magnitude understanding, and arithmetic with fractions in a randomized controlled pretest–intervention–posttest design. The game included NLE with feedback but no direct instruction. A sample of 188 fifth- to eighth-graders participated in a fraction number line game condition, a scaffolded fraction number line games condition, or an active control condition. In fifth- and sixth-graders, participation in the intervention improved the trained measure of fraction understanding (NLE on 0–1 line) but left unchanged two untrained measures of fraction understanding (NLE on 0–5 lines and fraction comparison) and a measure of fraction arithmetic. Seventh- and eighth-graders showed no intervention effects. The lack of transfer in fifth- and sixth-graders indicates that gamified NLE interventions can complement but not replace more direct instruction on fraction concepts and fraction arithmetic.

Beyond categories: dynamic qualitative analysis of visuospatial representation in arithmetic

Visuospatial representations of numbers and their relationships are widely used in mathematics education. These include drawn images, models constructed with concrete manipulatives, enactive/embodied forms, computer graphics, and more. This paper addresses the analytical limitations and ethical implications of methodologies that use broad categorizations of representations and argues the benefits of dynamic qualitative analysis of arithmetical-representational strategy across multiple semi-independent aspects of display, calculation, and interaction. It proposes an alternative methodological approach combining the structured organization of classification with the detailed nuance of description and describes a systematic but flexible framework for analysing nonstandard visuospatial representations of early arithmetic. This approach is intended for use by researchers or practitioners, for interpretation of multimodal and nonstandard visuospatial representations, and for identification of small differences in learners’ developing arithmetical-representational strategies, including changes over time. Application is illustrated using selected data from a microanalytic study of struggling students’ multiplication and division in scenario tasks.

Cerebellar signals drive motor adjustments and visual perceptual changes during forward and backward adaptation of reactive saccades.

Saccadic adaptation ($SA$) is a cerebellar-dependent learning of motor commands ($MC$), which aims at preserving saccade accuracy. Since $SA$ alters visual localization during fixation and even more so across saccades, it could also involve changes of target and/or saccade visuospatial representations, the latter ($CDv$) resulting from a motor-to-visual transformation (forward dynamics model) of the corollary discharge of the $MC$. In the present study, we investigated if, in addition to its established role in adaptive adjustment of $MC$, the cerebellum could contribute to the adaptation-associated perceptual changes. Transfer of backward and forward adaptation to spatial perceptual performance (during ocular fixation and trans-saccadically) was assessed in eight cerebellar patients and eight healthy volunteers. In healthy participants, both types of $SA$ altered $MC$ as well as internal representations of the saccade target and of the saccadic eye displacement. In patients, adaptation-related adjustments of $MC$ and adaptation transfer to localization were strongly reduced relative to healthy participants, unraveling abnormal adaptation-related changes of target and $CDv$. Importantly, the estimated changes of $CDv$ were totally abolished following forward session but mainly preserved in backward session, suggesting that an internal model ensuring trans-saccadic localization could be located in the adaptation-related cerebellar networks or in downstream networks, respectively.

The irrelevant speech effect in backward recall is modulated by foreknowledge of recall direction and response modality.

In backward immediate serial recall, participants recall lists of items immediately after their presentation by beginning with the last presented item and ending with the first presented one. Despite the similarities with forward recall in which participants recall the items from the first to the last presented, benchmark memory phenomena reliably found in forward recall are not constantly observed in backward recall. Here, we proposed a new framework called the encoding-retrieval matching (ERM) hypothesis to account for backward recall. The ERM retains the main features of the visuospatial hypothesis and the item-order trade-off hypothesis, the two dominant accounts of backward recall. According to the ERM, output modality and foreknowledge of recall direction influence the availability of visuospatial representations and the weight devoted to item and order processing. We tested the ERM with irrelevant speech, a well-known working memory factor disrupting forward recall. In two experiments, we manipulated recall direction (forward vs. backward), irrelevant speech (control vs. irrelevant speech), and response modality (manual vs. oral). As predicted by the ERM, when recall direction was unpredictable in Experiment 1, the magnitude of the irrelevant speech effect was larger in backward manual recall than in backward oral recall. In Experiment 2, recall direction was predictable. As predicted by the ERM, in backward recall, the irrelevant speech effect was reduced with a manual response and absent with an oral response. We concluded that ERM effectively accounts for the complex interplay between response modality, foreknowledge of recall direction, and benchmark memory effects in backward recall. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Visuospatial working memory abilities and spontaneous sensations perception

Aim: Body awareness arises when attending to and maintaining awareness of visuospatial body representations. By the same token, focussing on representations transfers them to working memory. Body awareness and working memory seemingly rely on similar processes and recruit common parietal areas involved in perception. Therefore, we asked whether visuospatial working memory abilities would define individual differences in the perception of spontaneous sensations (SPS), i.e., bodily sensations perceived in the absence of triggers (e.g., tactile stimulation or movement), when attending to the body. Method: Participants completed two visuospatial working memory tasks to assess various mechanisms: (i) the decay of representations was assessed through a Brown-Peterson task in which the delay between the memorandum presentation and its recall was manipulated, and (ii) the impact of distractors’ interference and cognitive load (i.e., complexity) on recall performances were assessed through a complex span task that required the processing of distractors while maintaining a memorandum. A standard SPS task involving localization and characterization of SPS perceived on the hands was completed afterwards. Results: Low performance due to decay, distractors’ interference and cognitive load in visuospatial working memory was associated with a decrease in the frequency of SPS. Additionally, low performance due to distractors’ cognitive load predicted a decrease in the perception of surface-type sensations, and high performance despite distractors’ interference led to a better perception of SPS on less sensitive areas of the hand. Conclusion: We discuss how visuospatial working memory processes might contribute to body awareness and perceptual distortions of the body.

Serial reproduction reveals the geometry of visuospatial representations

An essential function of the human visual system is to locate objects in space and navigate the environment. Due to limited resources, the visual system achieves this by combining imperfect sensory information with a belief state about locations in a scene, resulting in systematic distortions and biases. These biases can be captured by a Bayesian model in which internal beliefs are expressed in a prior probability distribution over locations in a scene. We introduce a paradigm that enables us to measure these priors by iterating a simple memory task where the response of one participant becomes the stimulus for the next. This approach reveals an unprecedented richness and level of detail in these priors, suggesting a different way to think about biases in spatial memory. A prior distribution on locations in a visual scene can reflect the selective allocation of coding resources to different visual regions during encoding ("efficient encoding"). This selective allocation predicts that locations in the scene will be encoded with variable precision, in contrast to previous work that has assumed fixed encoding precision regardless of location. We demonstrate that perceptual biases covary with variations in discrimination accuracy, a finding that is aligned with simulations of our efficient encoding model but not the traditional fixed encoding view. This work demonstrates the promise of using nonparametric data-driven approaches that combine crowdsourcing with the careful curation of information transmission within social networks to reveal the hidden structure of shared visual representations.