Biology subjects

Yuval-Greenberg, S.

Publications and source records attributed to Yuval-Greenberg, S..

12 recordsLinked to original sources

bioRxiv2026

When exploration replaces storage: how eye movements shape visual working memory

Visual working memory (VWM) is traditionally studied while constraining eye movements and limiting access to visual input, yet in natural vision humans constantly explore and resample their environment. Only a few studies have examined VWM utilization when participants were allowed to interact with the environment and found that participants often preferred to resample their environment rather than rely on VWM storage. However, since eye movements were not controlled in these studies, the link between VWM utilization and free visual exploration remained unknown. In two experiments (N = 40), we investigated how visual exploration shapes reliance on VWM versus perceptual input. Participants searched for a common target across two item sets and could either store multiple items for comparison or repeatedly resample the sets by switching between them. Results revealed that when switching was achieved through eye movements, participants consistently relied more on visual resampling and less on VWM; in contrast, when switching required a manual response, they shifted toward greater VWM use. This pattern persisted even when peripheral input was equated, suggesting that natural exploration through eye movements reduces the cognitive cost of acquiring visual information, leading to a strategic reduction in VWM use. Our findings challenge fixation-based approaches to VWM research and highlight the importance of studying cognition under ecological viewing conditions.

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bioRxiv2024

The interpretation attributed to observed gaze shifts affects their social-cueing effect

In a world overloaded with sensory input, organisms use spatial attention to selectively process the most relevant information. For a highly social species like humans, one influential attentional cue is the direction of other peoples gaze: by perceiving where others look and following their gaze, observers can increase their chances of detecting important information. This well-established phenomenon, called the gaze cueing effect (GCE), is traditionally considered reflexive. However, gaze-shifts do not always indicate external attention; they can also occur for other reasons, such as when attention is shifted inwards during effortful cognitive processing. The ability of observers to interpret the eye movements of other people correctly, while dissociating inwards and outwards attention shifts, is critical for efficient management of their attentional resources. In this study, we examined the role of context on the interpretation of other peoples gaze. Across two preregistered experiments (total N=110), participants viewed gaze-shifts while performing a perceptual task. One group was primed to interpret gaze-shifts as reflecting inward attention deployment during cognitive effort, while the other was not provided with an interpretive context. The results revealed that GCE was reduced when gaze-shifts were perceived as linked to cognitive effort rather than external attention, indicating that attentional responses to gaze cues are context-dependent rather than purely reflexive. These findings highlight the flexibility of social attention, revealing that higher-order cognitive interpretation can override well-established attentional mechanisms. With its interdisciplinary approach, reexamining attentional processes in light of social cognition, this study offers new perspectives on the multifaceted socio-cognitive mind. Significance statementIn a world overflowing with sensory input, our attention is a limited resource which must be allocated efficiently. One way we manage this is by attending to locations where other people look, assuming their gaze points to something important. This study shows this mechanism of attention shift is not automatic. Instead, individuals interpret what the eye movements reflect and modulate their attention shifts accordingly. When observers believed that a person was thinking rather than looking at something meaningful, they were less likely to shift their attention in the same direction. These findings challenge the long-standing idea that humans reflexively follow others gaze and reveal that our attention is guided not just by where people look, but by what we think is happening in their minds. This insight has real-world implications for improving communication, education, and the design of socially aware technologies like virtual assistants or classroom tools.

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bioRxiv2023

Exposure to temporal randomness promotes subsequent adaptation to new temporal regularities

Noise is intuitively thought to interfere with perceptual learning; However, human and machine learning studies suggest that, in certain contexts, variability may reduce overfitting and improve generalizability. Whereas previous studies have examined the effects of variability in learned stimuli or tasks, it is hitherto unknown what are the effects of variability in the temporal environment. Here, we examined this question in two groups of adult participants (N=40) presented with visual targets at either random or fixed temporal routines and then tested on the same type of targets at a new nearly-fixed temporal routine. Findings reveal that participants of the random group performed better and adapted quicker following a change in the timing routine, relative to participants of the fixed group. Corroborated with eye-tracking and computational modeling, these findings suggest that prior exposure to temporal randomness promotes the formation of new temporal expectations and enhances generalizability in a dynamic environment. We conclude that noise plays an important role in promotion perceptual learning in the temporal domain: rather than interfering with the formation of temporal expectations, noise enhances them. This counterintuitive effect is hypothesized to be achieved through eliminating overfitting and promoting generalizability.

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bioRxiv2023

Sequential effect in pre-stimulus oculomotor inhibition

When faced with unfamiliar circumstances, we often turn to our past experiences with similar situations to shape our expectations. This results in the well-established sequential effect, in which previous trials influence the expectations of the current trial. Studies have revealed that, in addition to the classical behavioral metrics, the inhibition of eye movement could be used as a biomarker to study temporal expectations. This pre-stimulus oculomotor inhibition is found a few hundred milliseconds prior to predictable events, with a stronger inhibition for predictable than unpredictable events. The phenomenon has been found to occur in various temporal structures, such as rhythms, cue-association and conditional probability, yet it is still unknown whether it reflects local sequential information of the previous trial. To explore this, we examined the relationship between the sequential effect and the pre-stimulus oculomotor inhibition. Our results (N=40) revealed that inhibition was weaker when the previous trial was longer than the current trial, in line with findings of behavioral metrics. These findings indicate that the pre-stimulus oculomotor inhibition covaries with expectation based on local sequential information, demonstrating the tight connection between this phenomenon and expectation and providing a novel measurement for studying sequential effects in temporal expectation.

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bioRxiv2023

It's all about location: reliance on spatial rather than visual context when trying to remember

When people try to remember visual information, they often move their eyes similarly to encoding. The mechanism underlying this behavior has not yet been fully understood. Specifically, it is unclear whether the purpose of this behavior is to recreate the visual input produced during encoding, or the motor and spatial elements of encoding. In this experiment, participants (N=40) encoded pairs of greyscale objects, overlaying colored squares. During test, participants were asked about objects orientation, while presented with squares of the same colors, either at the same location (controlled trials) or switched in their locations (test trials) relative to encoding. Results show that during test trials, participants tended to gaze at the square appearing at the location where the remembered object was previously presented, rather than on the square of the same color. This indicates a superiority of motor and spatial elements of eye movements rather than near-peripheral visual cues.

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bioRxiv2023

The contribution of eye movements to memory retrieval depends on the visual input

When attempting to recall previously seen visual information, people often move their eyes to the same locations where they initially viewed it. These eye-movements are thought to serve a role in enhancing memory retrieval, although the exact mechanism underlying this effect is yet unknown. To investigate this link between eye-movements and memory, we conducted an experiment with 80 adult participants. Participants were asked to perform a memory retrieval task, while viewing either the same visual context as during encoding or an altered one. Results showed that the benefit of eye movements to memory retrieval was dependent on the visual input. This suggests that the contribution of eye-movements to memory may not be from the motor behavior itself, but from its visual consequences. Our findings thus challenge the hypothesis that eye movements act as a motor retrieval cue and support the view that their visual consequences act as a sensory one. Statement of RelevanceAn intriguing question in cognition is how humans encode memorized material and what helps them retrieve it. It is known that when an action or stimulus is repeated both when information is encoded and when it is retrieved, this can act as a retrieval cue and enhance memory performance. It is also known that people tend to reenact the same eye movements during retrieval as they did during encoding, and this behavior is associated with higher memory performance. This has led to the hypothesis that eye movements act as a retrieval cue. However, we challenge this hypothesis by showing that the visual consequences of eye movements, rather than the motor action that accompanies them, is the key factor for memory enhancement. Understanding the factors that influence memory provides crucial insight into the relationship between external behaviors and internal memory processes, leading to significant implications for the educational and clinical settings.

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bioRxiv2022

What makes eye movements effective retrieval cue: The contribution of visual and the motor components to memory performance

During memory retrieval, people tend to reenact the same eye movements performed when memorized items were first displayed and to gaze at similar locations. This was hypothesized to reflect the role of eye movements as retrieval cues. However, it is unknown what is it about eye movements that makes them effective retrieval cues. Here, we examine, for the first time, the individual and combined contributions of the visual and the motor components of eye movements to memory retrieval. Results (N=70) revealed a non-additive benefit of both components of eye movements to memory performance. Additionally, we found that individuals who gained from one component, were more likely to gain from the other as well. Together, these findings unravel the central role of eye movements in episodic memory; they show how the visual and motor components are integrated into a single effective memory retrieval cue and how this integration varies among individuals.

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bioRxiv2021

The spatiotemporal link of temporal expectations: contextual temporal expectation is independent of spatial attention

Temporal expectation is the ability to construct predictions regarding the timing of events, based on previously-experienced temporal regularities of different types. For example, cue-based expectations are constructed when a cue validly indicates when a target is expected to occur. However, in the absence of such cues, expectations can be constructed based on contextual temporal information, including the events hazard-rate function - its moment-by-moment conditional probability that changes over time; and prior experiences, which provide probabilistic information regarding the events predicted timing (sequential effects). It was previously suggested that cue-based temporal expectation is exerted via synchronization of spatially-specific neural activity at a target's predictable time, within receptive fields corresponding to the targets expected location. Here, we tested if the same theoretical model holds for contextual temporal effects. Participants (n = 40) performed a speeded spatial-cueing detection task, with two-thirds valid spatial cues. The targets hazard-rate function was modulated by varying the foreperiod - the interval between the spatial cue and the target - among trials, and was manipulated between groups by changing the interval distribution. Reaction times were analyzed using both frequentist and Bayesian generalized linear mixed models, accounting for hazard and sequential effects. Results showed that the effects of contextual temporal structures on reaction times were independent of spatial attention. This suggests that the spatiotemporal mechanisms, thought to account for cue-based expectation, cannot explain other sources of temporal expectations. We conclude that expectations based on contextual structures have different characteristics than cue-based temporal expectation, suggesting reliance on distinct neural mechanisms. Significance statementTemporal expectation is the ability to predict an event onset based on temporal regularities. A neurophysiological model suggested that temporal expectation relies on the synchronization of spatially-specific neurons whose receptive fields represent the attended location. This model predicts that temporal expectation would be evident solely within the locus of spatial attention. Existing evidence supported this model for expectation based on associations between a temporal cue and a target, but here we show that it cannot account for another source of temporal expectation - expectation that is based on contextual information, i.e. hazard-rate and recent priors. These findings reveal the existence of different predictive mechanisms for cued and contextual temporal predictions, with the former depending on spatial attention and the latter non-spatially-specific.

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bioRxiv2020

Pre-target oculomotor inhibition reflects temporal orienting rather than certainty

Recent studies suggested that eye movements are linked to temporal predictability. These studies manipulated predictability by setting the cue-target interval (foreperiod) to be fixed or random throughout block. Findings showed that pre-target oculomotor behavior was reduced in the fixed relative to the random condition. This effect was interpreted as reflecting the formation of temporal expectation. However, it is unknown whether the effect is driven by target-specific temporal orienting, or rather a result of a more context-dependent state of certainty that participants may experience during blocks with a high predictability rate. In thus study we dissociated certainty and orienting in a tilt-discrimination task. In each trial, a temporal cue (fixation color change) was followed by a tilted grating-patch. The foreperiod distribution was varied between blocks to be either fully fixed (same foreperiod in 100% of trials), mostly fixed (80% of trials with one foreperiod and 20% with another) or random (five foreperiods in equal probabilities). The two hypotheses led to different prediction models which were tested against the experimental data. Results were consistent with the orienting hypothesis and inconsistent with the certainty hypothesis, supporting the link between oculomotor inhibition and temporal orienting and its validity as a temporal expectations marker.

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bioRxiv2020

Oculomotor inhibition precedes temporally expected auditory targets

Eye movements are inhibited prior to the onset of temporally-predictable visual targets. This oculomotor inhibition effect could be considered a marker for the formation of temporal expectations and the allocation of temporal attention in the visual domain. Here we show that eye movements are also inhibited before predictable auditory targets. In two experiments, we manipulate the period between a cue and an auditory target to be either predictable or unpredictable. The findings show that although there is no perceptual gain from avoiding gaze-shifts in this procedure, saccades and blinks are inhibited prior to predictable relative to unpredictable auditory targets. These findings show that oculomotor inhibition occurs prior auditory targets. This link between auditory expectation and oculomotor behavior, in combination with the results of our parallel study in the tactile domain, reveals a multimodal perception action coupling, which has a central role in temporal expectations.

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bioRxiv2020

Oculomotor freezing reflects tactile temporal expectation and aids tactile perception

The oculomotor system keeps the eyes steady in expectation of visual events. Here, recording microsaccades while people performed a tactile, frequency discrimination task enabled us to test whether the oculomotor system shows an analogous preparatory response for unrelated tactile events. We manipulated the temporal predictability of tactile targets using tactile cues, which preceded the target by either constant (high predictability) or variable (low predictability) time intervals. We find that microsaccades are inhibited prior to tactile targets and more so for constant than variable intervals, revealing a tight crossmodal link between tactile temporal expectation and oculomotor action. These findings portray oculomotor freezing as a marker of crossmodal temporal expectation. Moreover, microsaccades occurring around the tactile target presentation are associated with reduced task performance, suggesting that oculomotor freezing mitigates potential detrimental, concomitant effects of microsaccades and revealing a crossmodal coupling between tactile perception and oculomotor action.

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bioRxiv2018

Directing voluntary temporal attention increases fixational stability

Our visual input is constantly changing, but not all moments are equally relevant. Temporal attention, the prioritization of visual information at specific points in time, increases perceptual sensitivity at behaviorally relevant times. The dynamic processes underlying this increase are unclear. During fixation, humans make small eye movements called microsaccades, and inhibiting microsaccades improves perception of brief stimuli. Here we asked whether temporal attention changes the pattern of microsaccades in anticipation of brief stimuli. Human observers (female and male) judged brief stimuli presented within a short sequence. They were given either an informative precue to attend to one of the stimuli, which was likely to be probed, or an uninformative (neutral) precue. We found strong microsaccadic inhibition before the stimulus sequence, likely due to its predictable onset. Critically, this anticipatory inhibition was stronger when the first target in the sequence (T1) was precued (task-relevant) than when the precue was uninformative. Moreover, the timing of the last microsaccade before T1 and the first microsaccade after T1 shifted, such that both occurred earlier when T1 was precued than when the precue was uninformative. Finally, the timing of the nearest pre- and post-T1 microsaccades affected task performance. Directing voluntary temporal attention therefore impacts microsaccades, helping to stabilize fixation at the most relevant moments, over and above the effect of predictability. Just as saccading to a relevant stimulus can be an overt correlate of the allocation of spatial attention, precisely timed gaze stabilization can be an overt correlate of the allocation of temporal attention.\n\nSignificance statementWe pay attention at moments in time when a relevant event is likely to occur. Such temporal attention improves our visual perception, but how it does so is not well understood. Here we discovered a new behavioral correlate of voluntary, or goal-directed, temporal attention. We found that the pattern of small fixational eye movements called microsaccades changes around behaviorally relevant moments in a way that stabilizes the position of the eyes. Microsaccades during a brief visual stimulus can impair perception of that stimulus. Therefore, such fixation stabilization may contribute to the improvement of visual perception at attended times. This link suggests that in addition to cortical areas, subcortical areas mediating eye movements may be recruited with temporal attention.

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