Eye movements during scene inspection: A test of the saliency map hypothesis

Underwood, Geoffrey; Foulsham, Tom; Loon, Editha van; Humphreys, Louise; Bloyce, Jackie

doi:10.1080/09541440500236661

Cited by 109 publications

(90 citation statements)

References 26 publications

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“…The demands of the task allowed them to focus upon the search for a target, with cognitive override of low-level features either through avoidance of the process of building the saliency map or through disregard of the saliency peaks. This also confirms the result from the search task used by Underwood et al (2006), in which conspicuity was also ineffective in guiding eye movements. The cognitive override of visual saliency is also a feature of Torralba's (2003) model of contextual cueing, in which the visual context becomes available sufficiently early to allow modulation of the saliency map.…”

Section: Discussionsupporting

confidence: 78%

“…This confirms the predictions of models of visual attention that suggest that viewers first determine the regions of low-level variation and build a saliency map that is used to direct the initial eye movements around the scene (Findlay and Walker, 1999;Henderson et al, 1999;Itti and Koch, 2000). It also confirms the results from the memory experiment reported by Underwood et al (2006) in finding a relationship between conspicuity and the early fixation of an object. In Experiment 2 the viewers searched for a small target that was present in half the pictures, and here they were unaffected by conspicuity or congruency.…”

Section: Discussionsupporting

confidence: 78%

“…These instructions possibly precluded the top-down influences seen in the search experiments reported by Rao, Zelinsky, Hayhoe and Ballard (2002) and by Wolfe, Horowitz, Kenner, Hyle and Vasan (2004), in which expectations were influential. Itti and Koch's (2000) model was also supported in one of the experiments reported by Underwood, Foulsham, van Loon, Humphreys and Bloyce (2006). Viewers looked at photographs of office scenes in preparation for a recognition memory test, and early eye fixations were found to be more likely to be on a high saliency object (e.g., a brightly coloured coffee mug) than upon other objects in the scene (e.g., computer equipment, books, keys, and a piece of fruit).…”

mentioning

confidence: 66%

“…Experiment 1 had viewers look at pictures in preparation for a memory test, and in doing so they needed to look at the whole picture without looking at any specific object at the neglect of any other, and in Experiment 2 the viewers looked for the presence of a small target object in a directed search task. Henderson et al (1999) used both of these tasks in their investigation of congruency in picture perception, and Underwood et al (2006) found a variation in the influence of saliency between a memory task and a search task. Experiment 2 also used a search task, to allow comparison of the effects of saliency and congruency with the memory task of Experiment 1.…”

Section: Experiments 2 Focused Search For a Targetmentioning

confidence: 99%

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Visual saliency and semantic incongruency influence eye movements when inspecting pictures

Underwood

Foulsham

2006

Quarterly Journal of Experimental Psychology

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Models of low-level saliency predict that when we first look at a photograph our first few eye movements should be made towards visually conspicuous objects. Two experiments investigated this prediction by recording eye fixations while viewers inspected pictures of room interiors that contained objects with known saliency characteristics. Highly salient objects did attract fixations earlier than less conspicuous objects, but only in a task requiring general encoding of the whole picture. When they were required to detect the presence of a small target, then the visual saliency of non-target objects did not influence fixations. These results support modifications of the model that take the cognitive override of saliency into account by allowing task demands to reduce the saliency weights of task-irrelevant objects.The pictures sometimes contained incongruent objects that were taken from other rooms. These objects were used to test the hypothesis that previous reports of the early fixation of congruent objects have not been consistent because the effect depends upon the visual conspicuity of the incongruent object. There was an effect of incongruency in both experiments, with earlier fixation of objects that violated the gist of the scene, but the effect was only apparent for inconspicuous objects, arguing against this hypothesis. Address for correspondence:Geoffrey Underwood, School of Psychology, University of Nottingham, Nottingham NG7 2RD, UK. Email: geoff.underwood@nottingham.ac.uk or lpywtf@psychology.nottingham.ac.uk We are very grateful to Laurent Itti who generously made his saliency software available to us, and to Editha van Loon who helped install the software. We also thank Mike Burton, John Findlay and two anonymous reviewers for their helpful comments on a previous draft of this paper.Visual saliency and semantic incongruency 2 What attracts our attention when we first look at a picture of a scene such as a kitchen, a football match, or a harbour? Conspicuous objects might be expected to gain early inspection, and in two experiments here we investigated the effects of visual saliency and scene incongruency. The effects of visual and semantic conspicuity were observed in a free inspection task in which viewers prepared for a recognition memory test, and in a search task, in which they looked for a specific object. In each case we asked whether their early eye fixations would be taken to objects that were visually prominent by virtue of characteristics such as brightness and colour, and to objects that violated the gist of the scene by virtue of not being in their expected environment.Itti and Koch (2000) have developed an algorithm that enables the measurement of the visual saliency of an image on the basis of its physical properties, by the identification of peaks in the distribution of intensity and changes in colour and orientation. The algorithm builds an overall "saliency map" of the image that was suggested by Koch and Ullman (1985) to drive attentional selection of regions of displa...

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Section: Discussionsupporting

confidence: 78%

Section: Discussionsupporting

confidence: 78%

mentioning

confidence: 66%

Section: Experiments 2 Focused Search For a Targetmentioning

confidence: 99%

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Visual saliency and semantic incongruency influence eye movements when inspecting pictures

Underwood

Foulsham

2006

Quarterly Journal of Experimental Psychology

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222

182

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show abstract

“…Given any image, the algorithm computes a so-called saliency map. Saliency maps were tested with success in (Underwood et al, 2006), when the observer task is to memorize images. But it was also shown that when the task is to search for a particular object, this model is no longer valid.…”

Section: The Need For a New Approachmentioning

confidence: 99%

Towards the Estimation of Conspicuity With Visual Priors

Simon¹,

Tarel²,

Brémond³

2008

Proceedings of the Third International Conference on Computer Vision Theory and Applications

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Abstract:Traffic signs are designed to be clearly seen by drivers. However a little is known about the visual influence of the traffic sign environment on how it will be perceived. Computer estimation of the conspicuity from images using a camera mounted on a vehicle is thus of importance in order to be able to quickly make a diagnosis regarding conspicuity of traffic signs. Unfortunately, our knowledge about the human visual processing system is rather incomplete and thus conspicuity visual mechanisms remain poorly understood. A complete model for conspicuity is not known, only specific features are known to be of importance. It makes sense to assume that an important task for drivers is to search for traffic signs. We therefore propose a new paradigm for conspicuity estimation in search tasks based on statistical learning of the visual features of the object of interest.

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Something Overlooked? How experts in change detection use visual saliency

Lansdale

Underwood

Davies

2009

Applied Cognitive Psychology

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How does expertise in the analysis of particular images influence the effects of visual saliency upon attention? Expert analysts of aerial photographs and untrained viewers undertook change-detection and location memory tasks using aerial photographs with eye movements recorded throughout. Experts were more accurate in both tasks. Significant differences were also seen in the scanpaths: Untrained viewers fixated preferentially upon salient features throughout stimulus presentation whereas experts did not. However, both groups showed a strong influence of saliency in change detection and memory tasks. We interpret this apparent contradiction by: (i) assuming that the use of saliency in visual search is discretionary, and experts can use semantic information to prioritise where to fixate next; whereas, (ii) in tasks requiring spatial memory, analysis of visual saliency delivers easily acquired landmarks to reference the location of items in an image; a previously overlooked function used by expert and untrained viewers alike.How do we decide where to look in an image, and how much do bottom-up and top-down processes influence the decision? At one extreme, Itti and Koch (2000) developed a bottom-up model to predict where attention is directed on the basis of visual saliency. Saliency was defined by low-level visual characteristics of the image such as colour, intensity and orientation and the model predicted that areas of high saliency should attract the viewer's attention. Thus fixations are directed first to the region of highest saliency, then to the area of next highest saliency and so on in a quasi-automatic way.However, it is clear that visual search is open to top-down cognitive influences. When we inspect a scene, we direct our attention to the most likely locations rather than to the most visually salient objects in view (e.g. Torralba, Oliva, Castelhano, & Henderson, 2006). Underwood, Jebbett, and Roberts (2004) have also demonstrated the selective nature of searching for information in pictures in a task in which participants judged whether a sentence correctly representing a scene. Compared to seeing the picture first, participants viewing the image after the sentence made fewer fixations overall and these fixations were guided to the objects described in the sentence. The influence of saliency on early fixations is also diminished in tasks when participants search for a specific object; in which case participants are less likely to be distracted by conspicuous non-targets (Underwood, APPLIED COGNITIVE PSYCHOLOGY

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Eye movements during scene inspection: A test of the saliency map hypothesis

Cited by 109 publications

References 26 publications

Visual saliency and semantic incongruency influence eye movements when inspecting pictures

Visual saliency and semantic incongruency influence eye movements when inspecting pictures

Towards the Estimation of Conspicuity With Visual Priors

Something Overlooked? How experts in change detection use visual saliency

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