scholarly journals Cat and mouse search: the influence of scene and object analysis on eye movements when targets change locations during search

2017 ◽  
Vol 372 (1714) ◽  
pp. 20160106 ◽  
Author(s):  
Anne P. Hillstrom ◽  
Joice D. Segabinazi ◽  
Hayward J. Godwin ◽  
Simon P. Liversedge ◽  
Valerie Benson
Keyword(s):  
Eye Movements ◽  
Target Location ◽  
Saccadic Eye Movements ◽  
Movement Planning ◽  
Scene Analysis ◽  
Object Properties ◽  
Visual Mask ◽  
Visible Object ◽  
Scene Gist ◽  
Trial Participants

We explored the influence of early scene analysis and visible object characteristics on eye movements when searching for objects in photographs of scenes. On each trial, participants were shown sequentially either a scene preview or a uniform grey screen (250 ms), a visual mask, the name of the target and the scene, now including the target at a likely location. During the participant's first saccade during search, the target location was changed to: (i) a different likely location, (ii) an unlikely but possible location or (iii) a very implausible location. The results showed that the first saccade landed more often on the likely location in which the target re-appeared than on unlikely or implausible locations, and overall the first saccade landed nearer the first target location with a preview than without. Hence, rapid scene analysis influenced initial eye movement planning, but availability of the target rapidly modified that plan. After the target moved, it was found more quickly when it appeared in a likely location than when it appeared in an unlikely or implausible location. The findings show that both scene gist and object properties are extracted rapidly, and are used in conjunction to guide saccadic eye movements during visual search. This article is part of the themed issue ‘Auditory and visual scene analysis’.

scholarly journals Saccades and smooth pursuit eye movements trigger equivalent gaze-cued orienting effects

2018 ◽  
Vol 71 (9) ◽  
pp. 1860-1872 ◽  
Author(s):  
Stephen RH Langton ◽  
Alex H McIntyre ◽  
Peter JB Hancock ◽  
Helmut Leder
Keyword(s):  
Eye Movements ◽  
Smooth Pursuit ◽  
Target Location ◽  
Eye Gaze ◽  
Saccadic Eye Movements ◽  
Gaze Shift ◽  
The Gaze ◽  
Orienting Effect ◽  
Motion Speed ◽  
Uncued Target

Research has established that a perceived eye gaze produces a concomitant shift in a viewer’s spatial attention in the direction of that gaze. The two experiments reported here investigate the extent to which the nature of the eye movement made by the gazer contributes to this orienting effect. On each trial in these experiments, participants were asked to make a speeded response to a target that could appear in a location toward which a centrally presented face had just gazed (a cued target) or in a location that was not the recipient of a gaze (an uncued target). The gaze cues consisted of either fast saccadic eye movements or slower smooth pursuit movements. Cued targets were responded to faster than uncued targets, and this gaze-cued orienting effect was found to be equivalent for each type of gaze shift both when the gazes were un-predictive of target location (Experiment 1) and counterpredictive of target location (Experiment 2). The results offer no support for the hypothesis that motion speed modulates gaze-cued orienting. However, they do suggest that motion of the eyes per se, regardless of the type of movement, may be sufficient to trigger an orienting effect.

Knowledge-based scene analysis with saccadic eye movements

1999 ◽  
Author(s):  
Kerstin Schill ◽  
Elisabeth Umkehrer ◽  
Stephan Beinlich ◽  
Gerhard Krieger ◽  
Christoph Zetzsche
Keyword(s):  
Eye Movements ◽  
Saccadic Eye Movements ◽  
Scene Analysis ◽  
Knowledge Based

Muscimol-Induced Inactivation of Monkey Frontal Eye Field: Effects on Visually and Memory-Guided Saccades

1999 ◽  
Vol 81 (5) ◽  
pp. 2191-2214 ◽  
Author(s):  
Elisa C. Dias ◽  
Mark A. Segraves
Keyword(s):  
Eye Movements ◽  
Target Location ◽  
Memory Task ◽  
Saccadic Eye Movements ◽  
Spatial Location ◽  
Frontal Eye Field ◽  
Visually Guided ◽  
Field Effects ◽  
Progressive Loss ◽  
Eye Field

Muscimol-induced inactivation of the monkey frontal eye field: effects on visually and memory-guided saccades. Although neurophysiological, anatomic, and imaging evidence suggest that the frontal eye field (FEF) participates in the generation of eye movements, chronic lesions of the FEF in both humans and monkeys appear to cause only minor deficits in visually guided saccade generation. Stronger effects are observed when subjects are tested in tasks with more cognitive requirements. We tested oculomotor function after acutely inactivating regions of the FEF to minimize the effects of plasticity and reallocation of function after the loss of the FEF and gain more insight into the FEF contribution to the guidance of eye movements in the intact brain. Inactivation was induced by microinjecting muscimol directly into physiologically defined sites in the FEF of three monkeys. FEF inactivation severely impaired the monkeys’ performance of both visually guided and memory-guided saccades. The monkeys initiated fewer saccades to the retinotopic representation of the inactivated FEF site than to any other location in the visual field. The saccades that were initiated had longer latencies, slower velocities, and larger targeting errors than controls. These effects were present both for visually guided and for memory-guided saccades, although the memory-guided saccades were more disrupted. Initially, the effects were restricted spatially, concentrating around the retinotopic representation at the center of the inactivated site, but, during the course of several hours, these effects spread to flanking representations. Predictability of target location and motivation of the monkey also affected saccadic performance. For memory-guided saccades, increases in the time during which the monkey had to remember the spatial location of a target resulted in further decreases in the accuracy of the saccades and in smaller peak velocities, suggesting a progressive loss of the capacity to maintain a representation of target location in relation to the fovea after FEF inactivation. In addition, the monkeys frequently made premature saccades to targets in the hemifield ipsilateral to the injection site when performing the memory task, indicating a deficit in the control of fixation that could be a consequence of an imbalance between ipsilateral and contralateral FEF activity after the injection. There was also a progressive loss of fixation accuracy, and the monkeys tended to restrict spontaneous visual scanning to the ipsilateral hemifield. These results emphasize the strong role of the FEF in the intact monkey in the generation of all voluntary saccadic eye movements, as well as in the control of fixation.

scholarly journals The Location Independence of Learned Attentional Flexibility

2020 ◽  
Author(s):  
Anthony Sali ◽  
Renate Ma ◽  
Mayuri S. Albal ◽  
Julianne Harper Key
Keyword(s):  
Eye Movements ◽  
Rapid Serial Visual Presentation ◽  
Visual Cues ◽  
Target Location ◽  
Saccadic Eye Movements ◽  
Visual Presentation ◽  
Block Type ◽  
Independent State ◽  
Single Location ◽  
Study Participants

Individuals are able to harness predictions about the likelihood of needing to shift attention to adjust their shift readiness, known as attentional flexibility. However, the nature of these predictions remain poorly understood. In the current study, participants made saccadic eye movements among three rapid serial visual presentation (RSVP) streams of alphanumeric characters in response to embedded visual cues and made button presses in response to targets at the cued location. We manipulated the overall likelihood of receiving a shift cue, known as the list-wide shift probability, across alternating blocks of trials and shifting attention to one of the streams, referred to as the oddball location, was equally likely regardless of the block type. Participants demonstrated smaller target detection shift costs and faster saccade latencies when the list-wide shift probability was high than when the list-wide probability was low and were faster to initiate saccades from the standard location than from the oddball location, reflecting learned modulations in flexibility. Furthermore, in high list-wide shift likelihood blocks, participants were faster to shift attention to the opposing standard target than to the oddball target. However, latencies for shifts to the oddball location in high list-wide shift probability blocks were shorter than those in low list-wide shift probability blocks, demonstrating that attentional flexibility is not yoked to a particular anticipated target location. Our findings provide evidence that moment-by-moment changes in attentional flexibility are not limited to an expectation to shift to a single location, but rather reflect, in part, a location-independent state of control.

The Accuracy of Saccadic and Perceptual Decisions in Visual Search

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 133-133
Author(s):  
M P Eckstein ◽  
B B Beutter ◽  
L S Stone
Keyword(s):  
Eye Movements ◽  
Spatial Information ◽  
Target Location ◽  
Signal To Noise Ratio ◽  
Saccadic Eye Movements ◽  
Noise Signal ◽  
Signal To Noise ◽  
Viewing Condition ◽  
Perceptual Performance ◽  
Noise Ratio

Saccadic eye movements during search for a target embedded in noise are suboptimally guided by information about target location (Eckstein et al, 1997, paper presented at ARVO). Our goal was to compare the spatial information used to guide the saccades with that used for the perceptual decision. Three observers were asked to determine the location of a bright disk (diameter 21 min arc) in white noise (signal-to-noise ratio 4.2) from among ten possible locations evenly spaced at 5.9 deg eccentricity. In the first of four conditions, observers used natural eye movements. In the three remaining conditions, observers fixated a central cross at all times. The fixation conditions consisted of three different presentation times (100, 200, 300 ms), each followed by a mask. Eye-position data were collected with a resolution of ∼0.2 deg. In the natural viewing condition, we measured the accuracy with respect to the target and the latency of the first saccade. In the fixation conditions, we discarded trials in which observers broke fixation. Perceptual performance was computed for all conditions. Averaged across observers, the first saccade was correct (closest to the target location) for 56±7 (SD) % of trials (chance 10%) and occurred after a latency of 313±56 ms. Perceptual performance averaged 53±4%, 63±4%, 65±2% correct at 100, 200, and 300 ms, respectively. We conclude that, for the signal-to-noise ratio used, at the time of initiation of the first saccade there is little difference between the amount of information about target location available to the perceptual and saccadic systems.

scholarly journals Increased preparation time reduces, but does not abolish, action history bias of saccadic eye movements

2019 ◽  
Vol 121 (4) ◽  
pp. 1478-1490 ◽  
Author(s):  
Eva-Maria Reuter ◽  
Welber Marinovic ◽  
Timothy N. Welsh ◽  
Timothy J. Carroll
Keyword(s):  
Eye Movements ◽  
Reaction Time ◽  
Target Location ◽  
Reaction Times ◽  
Saccadic Eye Movements ◽  
Limb Movements ◽  
Preparation Time ◽  
Movement History ◽  
Target Locations ◽  
Dependent Processes

The characteristics of movements are strongly history-dependent. Marinovic et al. (Marinovic W, Poh E, de Rugy A, Carroll TJ. eLife 6: e26713, 2017) showed that past experience influences the execution of limb movements through a combination of temporally stable processes that are strictly use dependent and dynamically evolving and context-dependent processes that reflect prediction of future actions. Here we tested the basis of history-dependent biases for multiple spatiotemporal features of saccadic eye movements under two preparation time conditions (long and short). Twenty people performed saccades to visual targets. To prompt context-specific expectations of most likely target locations, 1 of 12 potential target locations was specified on ~85% of the trials and each remaining target was presented on ~1% trials. In long preparation trials participants were shown the location of the next target 1 s before its presentation onset, whereas in short preparation trials each target was first specified as the cue to move. Saccade reaction times and direction were biased by recent saccade history but according to distinct spatial tuning profiles. Biases were purely expectation related for saccadic reaction times, which increased linearly as the distance from the repeated target location increased when preparation time was short but were similar to all targets when preparation time was long. By contrast, the directions of saccades were biased toward the repeated target in both preparation time conditions, although to a lesser extent when the target location was precued (long preparation). The results suggest that saccade history affects saccade dynamics via both use- and expectation-dependent mechanisms and that movement history has dissociable effects on reaction time and saccadic direction. NEW & NOTEWORTHY The characteristics of our movements are influenced not only by concurrent sensory inputs but also by how we have moved in the past. For limb movements, history effects involve both use-dependent processes due strictly to movement repetition and processes that reflect prediction of future actions. Here we show that saccade history also affects saccade dynamics via use- and expectation-dependent mechanisms but that movement history has dissociable effects on saccade reaction time and direction.

Neural Correlates of Fixation Duration during Real-world Scene Viewing: Evidence from Fixation-related (FIRE) fMRI

2015 ◽  
Vol 27 (6) ◽  
pp. 1137-1145 ◽  
Author(s):  
John M. Henderson ◽  
Wonil Choi
Keyword(s):  
Eye Movements ◽  
Cognitive Processes ◽  
Fixation Duration ◽  
Computational Models ◽  
Scene Perception ◽  
Motor Planning ◽  
Active Vision ◽  
Saccadic Eye Movements ◽  
Scene Analysis ◽  
Scene Viewing

During active scene perception, our eyes move from one location to another via saccadic eye movements, with the eyes fixating objects and scene elements for varying amounts of time. Much of the variability in fixation duration is accounted for by attentional, perceptual, and cognitive processes associated with scene analysis and comprehension. For this reason, current theories of active scene viewing attempt to account for the influence of attention and cognition on fixation duration. Yet almost nothing is known about the neurocognitive systems associated with variation in fixation duration during scene viewing. We addressed this topic using fixation-related fMRI, which involves coregistering high-resolution eye tracking and magnetic resonance scanning to conduct event-related fMRI analysis based on characteristics of eye movements. We observed that activation in visual and prefrontal executive control areas was positively correlated with fixation duration, whereas activation in ventral areas associated with scene encoding and medial superior frontal and paracentral regions associated with changing action plans was negatively correlated with fixation duration. The results suggest that fixation duration in scene viewing is controlled by cognitive processes associated with real-time scene analysis interacting with motor planning, consistent with current computational models of active vision for scene perception.

scholarly journals Object and scene analysis by saccadic eye-movements: an investigation with higher-order statistics

2000 ◽  
Vol 13 (2-3) ◽  
pp. 201-214 ◽  
Author(s):  
Christoph Zetzsche ◽  
Kerstin Schill ◽  
Gerhard Krieger ◽  
Gert Hauske ◽  
Ingo Rentschler
Keyword(s):  
Eye Movements ◽  
Order Statistics ◽  
Saccadic Eye Movements ◽  
Higher Order ◽  
Scene Analysis ◽  
Higher Order Statistics

scholarly journals Parietal Representation of Object-Based Saccades

2002 ◽  
Vol 88 (4) ◽  
pp. 1815-1829 ◽  
Author(s):  
Philip N. Sabes ◽  
Boris Breznen ◽  
Richard A. Andersen
Keyword(s):  
Eye Movements ◽  
Target Location ◽  
Saccadic Eye Movements ◽  
Object Orientation ◽  
Saccade Target ◽  
Spatial Variables ◽  
Preferred Direction ◽  
Orientation Effects ◽  
Object Based ◽  
Saccade Task

When monkeys make saccadic eye movements to simple visual targets, neurons in the lateral intraparietal area (LIP) display a retinotopic, or eye-centered, coding of the target location. However natural saccadic eye movements are often directed at objects or parts of objects in the visual scene. In this paper we investigate whether LIP represents saccadic eye movements differently when the target is specified as part of a visually displayed object. Monkeys were trained to perform an object-based saccade task that required them to make saccades to previously cued parts of an abstract object after the object reappeared in a new orientation. We recorded single neurons in area LIP of two macaque monkeys and analyzed their activity in the object-based saccade task, as well as two control tasks: a standard memory saccade task and a fixation task with passive object viewing. The majority of LIP neurons that were tuned in the memory saccade task were also tuned in the object-based saccade task. Using a hierarchical generalized linear model analysis, we compared the effects of three different spatial variables on the firing rate: the retinotopic location of the target, the object-fixed location of the target, and the orientation of the object in space. There was no evidence of an explicit object-fixed representation in the activity in LIP during either of the object-based tasks. In other words, no cells had receptive fields that rotated with the object. While some cells showed a modulation of activity due to the location of the target on the object, these variations were small compared to the retinotopic effects. For most cells, firing rates were best accounted for by either the retinotopic direction of the movement, the orientation of the object, or both spatial variables. The preferred direction of these retinotopic and object orientation effects were found to be invariant across tasks. On average, the object orientation effects were consistent with the retinotopic coding of potential target locations on the object. This interpretation is supported by the fact that the magnitude of these two effects were roughly equal in the early portions of the trial, but around the time of the motor response, the retinotopic effects dominated. We conclude that LIP uses the same retinotopic coding of saccade target whether the target is specified as an absolute point in space or as a location on a moving object.

The neural encoding of the location of targets for saccadic eye movements

1989 ◽  
Vol 146 (1) ◽  
pp. 195-207
Author(s):  
D. L. Sparks
Keyword(s):  
Eye Movements ◽  
Parietal Cortex ◽  
Target Location ◽  
Visual Target ◽  
Target Position ◽  
Saccadic Eye Movements ◽  
Neural Encoding ◽  
Neural Representations ◽  
Neurophysiological Data ◽  
Motor Error

Current models of the saccadic system imply that there are at least three neural representations of a visual target to which a saccade is made: representations in retinal, spatial (head or body) and motor coordinates. This paper presents the evidence supporting these models and summarizes the available neurophysiological data concerning neural representations of target location. In the superior colliculus, neurones in the superficial layers encode target location in retinal coordinates. Neurones in the deeper layers responsive to auditory and visual stimuli carry motor error signals. Evidence is also accumulating that some neurones in the thalamus and the frontal and parietal cortex convey information about target position with respect to the head or body, but these studies are far from complete.

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