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Journal ArticleDOI

More evidence for sensorimotor adaptation in color perception.

01 Sep 2005-Journal of Vision (Association for Research in Vision and Ophthalmology)-Vol. 6, Iss: 2, pp 145-153
TL;DR: It is shown that sensorim motor adaptation can be obtained for color, as a consequence of the introduction of a new sensorimotor contingency between eye movements and color changes.
Abstract: Sensorimotor adaptation can be defined as a perceptual adaptation whose effects depend on the occurrence and nature of the performed motor actions. Examples of sensorimotor adaptation can be found in the literature on prisms concerning several space-related attributes like orientation, curvature, and size. In this article, we show that sensorimotor adaptation can be obtained for color, as a consequence of the introduction of a new sensorimotor contingency between eye movements and color changes. In an adaptation phase, trials involved the successive presentation of two patches, first on the left, and then on the right or the opposite. The left patch being always red and the right patch green, a correlation is introduced between left–right (respectively right–left) eye saccades and red–green (respectively green–red) color change. After 40 min of adaptation, when two yellow patches are successively presented on each side of the screen, the chromaticity of the left and right patches need respectively to be shifted toward the chromaticity of the red and green adaptation patches for subjective equality to be obtained. When the eyes are kept fixed during the adaptation stage, creating a strong nonhomogeneity in retinal adaptation, no effect is found. This ensures that, if present, adaptation at a given retinal location cannot explain the present effect. A third experiment shows a dependency of the effect on the eyes' saccadic movements and not on the position on the screen, that is, on the position of the eyes in the orbits. These results argue for the involvement of sensorimotor mechanisms in color perception. The relation of these experimental findings toward a sensorimotor theory of color perception is discussed.

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Citations
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Journal ArticleDOI
TL;DR: It is found that shape judgments depended on the changes experienced during the learning phase and that they were similar in both the saccade and fixation conditions, suggesting that a general associative process contributes to the perception of shape across viewpoints.
Abstract: The cortical representations of a visual object differ radically across saccades. Several studies claim that the visual system adapts the peripheral percept to better match the subsequent foveal view. Recently, Herwig, Weis, and Schneider (2015, Annals of the New York Academy of Sciences, 1339(1), 97–105) found that the perception of shape demonstrates a saccade-dependent learning effect. Here, we ask whether this learning actually requires saccades. We replicated Herwig et al.’s (2015) study and introduced a fixation condition. In a learning phase, participants were exposed to objects whose shape systematically changed during a saccade, or during a displacement from peripheral to foveal vision (without a saccade). In a subsequent test, objects were perceived as less (more) curved if they previously changed from more circular (triangular) in the periphery to more triangular (circular) in the fovea. Importantly, this pattern was seen both with and without saccades. We then tested whether a variable delay between the presentations of the peripheral and foveal objects would affect their association—hypothetically weakening it at longer delays. Again, we found that shape judgments depended on the changes experienced during the learning phase and that they were similar in both the saccade and fixation conditions. Surprisingly, they were not affected by the delay between the peripheral and foveal presentations over the range we tested. These results suggest that a general associative process, independent of saccade execution, contributes to the perception of shape across viewpoints.

20 citations


Cites background from "More evidence for sensorimotor adap..."

  • ...This would be the case for color adaptation (Bompas & O’Regan, 2006), perception in binocular rivalry (Marx & Einhäuser, 2015), or the disambiguation of bistable stimuli (Haijiang, Saunders, Stone, & Backus, 2006)....

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  • ...This phenomenon of object constancy might be explained in terms of sensorimotor contingencies that the visual system would learn between eye movements and saccade-induced changes in the retinal inputs (Bompas & O’Regan, 2006; O’Regan & Noë, 2001)....

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Journal ArticleDOI
TL;DR: Sensorimotor adaptation can be a remarkably powerful influence on perception; because it operates in a compensatory direction, it may oppose the effects of sensory integration, depending upon task demands.
Abstract: When a body movement systematically co-occurs with a stimulus, a change in perception to compensate for this correlation may occur. In Experiment 1 (similar to A. Bompas & J. K. O'Regan, 2006), we induced a correlation between leftward eye saccades and a red stimulus, and rightward eye saccades and a green stimulus. In a subsequent test phase, observers compared the color of two stimuli after leftward and rightward saccades. The major result was that stimuli tended to look greener after a leftward saccade and redder after a rightward saccade (A. Bompas & J. K. O'Regan, 2006). Measured here in meaningful units for the first time, the shift in the point of subjective equality was approximately d' = 0.4, a remarkably large effect for only 40 minutes of eye movement/color exposure. A control experiment ruled out a simple reduction in initial bias as the cause of the effect. In Experiment 2, we hypothesized that the blue of the sky might cause an initial bias to judge spots seen with upward gaze as "yellower"; this expectation was not met, but the basic effect was replicated and extended to other chromaticities and eye movement directions. Experiment 3 substituted listening to tones for the eye movements (a sensorisensory correlation) to explore differences between sensorimotor adaptation and sensory integration; neither effect was found for our task. Sensorimotor adaptation can be a remarkably powerful influence on perception; because it operates in a compensatory direction, it may oppose the effects of sensory integration, depending upon task demands.

19 citations


Cites background or methods from "More evidence for sensorimotor adap..."

  • ...Recently, Bompas and O’Regan (2006) provided experimental evidence for a similar type of learning but with colored patches on a monitor rather than spatial distortions caused by wedge prisms. The role of a sensorimotor mechanism in color perception, they argue, may have been first discovered by Kohler (1951), but he interpreted this effect as the result of adaptation to a contingency between color and eye position, rather than a movement of the eyes. Bompas and O’Regan (2006) had subjects judge the relative color of two spots (“greener” or “redder”), one coincident with a leftward saccade and one with a rightward saccade, both before and after a learning phase in which observers were introduced to a contingency between direction of eye movement and color....

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  • ...Recently, Bompas and O’Regan (2006) provided experimental evidence for a similar type of learning but with colored patches on a monitor rather than spatial distortions caused by wedge prisms. The role of a sensorimotor mechanism in color perception, they argue, may have been first discovered by Kohler (1951), but he interpreted this effect as the result of adaptation to a contingency between color and eye position, rather than a movement of the eyes....

    [...]

  • ...One important point about the study of Bompas and O’Regan (2006) has to do with the direction of the sensorimotor learning effect. The shift in PSE that they produced was in the same direction as typical adaptation to color that does not involve eye movements. Just as in chromatic adaptation, where being steadily exposed to a green field of light (for example) over time reduces the effective “greenness” of the light (Gibson & Radner, 1937; Helson & Michels, 1948; Jameson & Hurvich, 1972; Judd, 1940; many others), the effect detailed by Bompas and O’Regan was that subjects responded as if a spot looked the opposite of the hue that was paired with the eye movement in the learning phase. This complementary direction of adaptation has also been seen with blur (Webster, 1999), orientation (Greenlee, Magnussen, & Nordby, 1988), motion (Anstis, Verstraten, Frans, & Mather, 1998), and specific facial characteristics (Webster & MacLin, 1999), though not as part of a sensorimotor contingency. Following Held and Hein (1963), we refer to this direction of sensorimotor effect as “compensatory”....

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  • ...Recently, Bompas and O’Regan (2006) provided experimental evidence for a similar type of learning but with colored patches on a monitor rather than spatial distortions caused by wedge prisms. The role of a sensorimotor mechanism in color perception, they argue, may have been first discovered by Kohler (1951), but he interpreted this effect as the result of adaptation to a contingency between color and eye position, rather than a movement of the eyes. Bompas and O’Regan (2006) had subjects judge the relative color of two spots (“greener” or “redder”), one coincident with a leftward saccade and one with a rightward saccade, both before and after a learning phase in which observers were introduced to a contingency between direction of eye movement and color. A shift in color judgments was measured after the learning phase, providing evidence that observers altered their point of subjective equality (PSE) after being exposed to the contingency. In the learning phase, leftward eye movements were paired with red spots, rightward ones with green, and the observers later judged spots appearing on the left as relatively greener and spots appearing on the right as relatively redder than they had done in the prelearning control phase. In Experiment 1, we seek to replicate and extend the basic finding of Bompas and O’Regan (2006), introducing a contingency between eye movements and the appearance of red or green spots....

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  • ...The direction of the effect reported by Bompas and O’Regan (2006) makes this explanation seem unlikely: if two events are coincidental, then one event would signal both, not the opposite of the...

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Journal ArticleDOI
Jürgen Golz1
TL;DR: It is shown that the results of grey settings depend on whether subjects visually explore the stimulus by looking around or fixate their gaze exclusively on the test field, which could inflate variance, reduce comparability between different studies, and even lead to unwarranted conclusions if viewing behaviour unpredictably differs between experimental conditions.
Abstract: In numerous studies on colour constancy or colour induction subjects have to adjust a test field so that it looks achromatic. Their viewing behaviour during these settings is often not controlled or reported. Here I show that the results of grey settings depend on whether subjects visually explore the stimulus by looking around or fixate their gaze exclusively on the test field. Two different viewing instructions are compared with regard to the degree of constancy as measured by the shift of grey settings in coloured surrounds. In variegated surrounds (but not in uniform surrounds) there is a robust effect of viewing condition for all subjects and all surround chromaticities tested, in that exploration increases colour constancy compared to fixating the test field. Values of a colour constancy index are increased by as much as 20% (where 100% colour constancy means that the subject chooses as grey the mean chromaticity of the surround) with an average across all subjects and surrounds of 12.6%. Thus, if t...

18 citations

Journal ArticleDOI
TL;DR: It is concluded that perceptual and visuomotor consequences of trans-saccadic changes rely on learning mechanisms that are distinct but develop on similar time scales.
Abstract: Repeated exposure to a consistent trans-saccadic step in the position of the saccadic target reliably produces a change of saccadic gain, a well-established trans-saccadic motor learning phenomenon known as saccadic adaptation. Trans-saccadic changes can also produce perceptual effects. Specifically, a systematic increase or decrease in the size of the object that is being foveated changes the perceptually equivalent size between fovea and periphery. Previous studies have shown that this recalibration of perceived size can be established within a few dozen trials, persists overnight, and generalizes across hemifields. In the current study, we use a novel adjustment paradigm to characterize both temporally and spatially the learning process that subtends this form of recalibration, and directly compare its properties to those of saccadic adaptation. We observed that sinusoidal oscillations in the amplitude of the trans-saccadic change produce sinusoidal oscillations in the reported peripheral size, with a lag of under 10 trials. This is qualitatively similar to what has been observed in the case of saccadic adaptation. We also tested whether learning is generalized to the mirror location on the opposite hemifield for both size recalibration and saccade adaptation. Here the results were markedly different, showing almost complete generalization for recalibration and no generalization for saccadic adaptation. We conclude that perceptual and visuomotor consequences of trans-saccadic changes rely on learning mechanisms that are distinct but develop on similar time scales.

16 citations


Cites background from "More evidence for sensorimotor adap..."

  • ...Similarly, chromatic hues can be associated to presaccadic locations in the visual field, which in turn biases color perception (Bompas & O’Regan, 2006a; Bompas & O’Regan 2006b), and even the same identity can be associated to different objects viewed centrally and peripherally (Cox, Meier,…...

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  • ...…chromatic hues can be associated to presaccadic locations in the visual field, which in turn biases color perception (Bompas & O’Regan, 2006a; Bompas & O’Regan 2006b), and even the same identity can be associated to different objects viewed centrally and peripherally (Cox, Meier, Oertelt, &…...

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Journal ArticleDOI
12 Nov 2012-PLOS ONE
TL;DR: Improvements of SVV accuracy by visual feedback, which remained effective after removal of feedback for ≥18 min, rather resulted from a cognitive strategy than by adapting the internal estimate of the gravitational vertical.
Abstract: The brain constructs an internal estimate of the gravitational vertical by integrating multiple sensory signals. In darkness, systematic head-roll dependent errors in verticality estimates, as measured by the subjective visual vertical (SVV), occur. We hypothesized that visual feedback after each trial results in increased accuracy, as physiological adjustment errors (A−/E-effect) are likely based on central computational mechanisms and investigated whether such improvements were related to adaptational shifts of perceived vertical or to a higher cognitive strategy. We asked 12 healthy human subjects to adjust a luminous arrow to vertical in various head-roll positions (0 to 120deg right-ear down, 15deg steps). After each adjustment visual feedback was provided (lights on, display of previous adjustment and of an earth-vertical cross). Control trials consisted of SVV adjustments without feedback. At head-roll angles with the largest A-effect (90, 105, and 120deg), errors were reduced significantly (p 0.05) influenced. In seven subjects an additional session with two consecutive blocks (first with, then without visual feedback) was completed at 90, 105 and 120deg head-roll. In these positions the error-reduction by the previous visual feedback block remained significant over the consecutive 18–24 min (post-feedback block), i.e., was still significantly (p<0.002) different from the control trials. Eleven out of 12 subjects reported having consciously added a bias to their perceived vertical based on visual feedback in order to minimize errors. We conclude that improvements of SVV accuracy by visual feedback, which remained effective after removal of feedback for ≥18 min, rather resulted from a cognitive strategy than by adapting the internal estimate of the gravitational vertical. The mechanisms behind the SVV therefore, remained stable, which is also supported by the fact that SVV precision – depending mostly on otolith input - was not affected by visual feedback.

14 citations


Cites background from "More evidence for sensorimotor adap..."

  • ...[43,53,54,55,56,57,58], lack of perceptual learning in our study...

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References
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Journal ArticleDOI
TL;DR: The Psychophysics Toolbox is a software package that supports visual psychophysics and its routines provide an interface between a high-level interpreted language and the video display hardware.
Abstract: The Psychophysics Toolbox is a software package that supports visual psychophysics. Its routines provide an interface between a high-level interpreted language (MATLAB on the Macintosh) and the video display hardware. A set of example programs is included with the Toolbox distribution.

16,594 citations


"More evidence for sensorimotor adap..." refers methods in this paper

  • ...The stimuli were generated using Matlab with the psychophysics toolbox extension (Brainard, 1997; Pelli, 1997) on a PC....

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Journal ArticleDOI
TL;DR: The VideoToolbox is a free collection of two hundred C subroutines for Macintosh computers that calibrates and controls the computer-display interface to create accurately specified visual stimuli.
Abstract: The VideoToolbox is a free collection of two hundred C subroutines for Macintosh computers that calibrates and controls the computer-display interface to create accurately specified visual stimuli. High-level platform-independent languages like MATLAB are best for creating the numbers that describe the desired images. Low-level, computer-specific VideoToolbox routines control the hardware that transforms those numbers into a movie. Transcending the particular computer and language, we discuss the nature of the computer-display interface, and how to calibrate and control it.

10,084 citations


"More evidence for sensorimotor adap..." refers methods in this paper

  • ...The stimuli were generated using Matlab with the psychophysics toolbox extension (Brainard, 1997; Pelli, 1997) on a PC....

    [...]

Book
01 Jan 1966

6,307 citations

Book
01 Jan 1996
TL;DR: Professor Ripley brings together two crucial ideas in pattern recognition; statistical methods and machine learning via neural networks in this self-contained account.
Abstract: From the Publisher: Pattern recognition has long been studied in relation to many different (and mainly unrelated) applications, such as remote sensing, computer vision, space research, and medical imaging. In this book Professor Ripley brings together two crucial ideas in pattern recognition; statistical methods and machine learning via neural networks. Unifying principles are brought to the fore, and the author gives an overview of the state of the subject. Many examples are included to illustrate real problems in pattern recognition and how to overcome them.This is a self-contained account, ideal both as an introduction for non-specialists readers, and also as a handbook for the more expert reader.

5,632 citations

Journal Article
TL;DR: In this article, the authors propose that the brain produces an internal representation of the world, and the activation of this internal representation is assumed to give rise to the experience of seeing, but it leaves unexplained how the existence of such a detailed internal representation might produce visual consciousness.
Abstract: Many current neurophysiological, psychophysical, and psychological approaches to vision rest on the idea that when we see, the brain produces an internal representation of the world. The activation of this internal representation is assumed to give rise to the experience of seeing. The problem with this kind of approach is that it leaves unexplained how the existence of such a detailed internal representation might produce visual consciousness. An alternative proposal is made here. We propose that seeing is a way of acting. It is a particular way of exploring the environment. Activity in internal representations does not generate the experience of seeing. The outside world serves as its own, external, representation. The experience of seeing occurs when the organism masters what we call the governing laws of sensorimotor contingency. The advantage of this approach is that it provides a natural and principled way of accounting for visual consciousness, and for the differences in the perceived quality of sensory experience in the different sensory modalities. Several lines of empirical evidence are brought forward in support of the theory, in particular: evidence from experiments in sensorimotor adaptation, visual \"filling in,\" visual stability despite eye movements, change blindness, sensory substitution, and color perception.

2,271 citations