Limitations for Change Detection in Multiple Gabor Targets

Wright, Michael J.; Green, Alison; Baker, S S

doi:10.1080/135062800394784

Cited by 39 publications

(42 citation statements)

References 22 publications

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“…Thus, information loss during the comparison phase, or failure to make the relevant comparison between memory and the test array, did not impose a noticeable cost to performance in this task. This finding is consistent with other research that has shown that cuing a single item during the test display does not improve performance in the type of memory task used here (Vogel, Woodman, & Luck, 2001;Wright et al, 2000; but see Landman, Spekreijse, & Lamme, 2003).…”

Section: Resultssupporting

confidence: 92%

“…Thus, it is clear that the orientation of gratings can be encoded and maintained in memory very accurately. However, the ability to store more than one such grating appears to be severely limited, as has been shown in previous work (Wright, Green, & Baker, 2000). In Experiments grid of black and white dots, subtending 4.1º 4.1º, presented at each item position).…”

Section: Discussionmentioning

confidence: 85%

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Visual short-term memory operates more efficiently on boundary features than on surface features

Alvarez

Cavanagh

2008

Perception & Psychophysics

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346The short-term storage of visual information is a critical component of visual information processing. It enables incoming stimuli to be tracked and compared with current percepts and with other information already in short-term storage or in long-term storage. Early work on visual memory by Phillips (1974) revealed that there are two separate storage systems for visual information: One is a high-capacity sensory store, and the other is a shortterm store with a relatively limited capacity, referred to here as visual short-term memory. Recent work has shown that the upper limit on the number of objects that can be stored in visual short-term memory is quite small, on the order of about four or five simple objects (Luck & Vogel, 1997). The number that can be stored is limited both by an upper limit on the number of objects that can be stored and by the total amount of visual information that can be stored in memory. Thus, increasing the amount of information stored per object reduces the number of objects that can be stored (Alvarez & Cavanagh, 2004).The question addressed in the present article is whether the same abstract code, such as right-tilted or small, is stored regardless of the format in which that information was initially presented. It is easy to imagine abstract codes for verbal memory. For example, if asked to store the uppercase letters A, P, Q, T in verbal memory, there would be no difficulty in recognizing the lowercase letters a, p, q, t as the same, despite the change in physical appearance, presumably because the information has been encoded in an abstract form. Similarly, work on visual memory suggests that letter shape can be encoded with a somewhat abstract structural description, so that memory for conjunctions of color and shape is insensitive to font changes that preserve letter structure (e.g., A vs. A), whereas large impairments occur with changes that alter letter structure (e.g., A vs. a; Walker & Hinkley, 2003). Thus, it appears that, in some cases, visual memory stores complex shape information with an abstract structural code.In the present study, we explored whether boundary and surface features of objects are treated equally by visual short-term memory, as would be expected if visual short-term memory operates over abstract codes. Figure 1 illustrates the difference between boundary and surface orientation and between boundary and surface size. In Figure 1A two different objects with identical orientations are presented. On the left is a Gabor patch (a sine wave grating with contrast vignetted by a Gaussian envelope), and on the right is a single bar of the Gabor patch. Figure 1B highlights the boundary of each object. The boundary of the Gabor has no clear orientation, whereas the boundary of the bar has a strong rightward tilt. In contrast, within the boundary, the Gabor surface texture has a clear rightward tilt, whereas the bar texture (homogeneous black) A change detection task was used to estimate the visual short-term memory storage capacity for either the orientation o...

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Section: Resultssupporting

confidence: 92%

Section: Discussionmentioning

confidence: 85%

Visual short-term memory operates more efficiently on boundary features than on surface features

Alvarez

Cavanagh

2008

Perception & Psychophysics

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“…Finally, it has been suggested that change blindness may reflect limited-capacity mechanisms affecting information processing under conditions of multiple simultaneous stimulation (e.g., Wright, Green, & Baker, 2000). This might be related to the parallel deployment of attentional resources over multiple elements in the scene (e.g., Wright et al, 2000), or to the limitation in the number of stimuli/ spatial positions that can access consciousness at any one time (e.g., Atkinson, Campbell, & Francis, 1976;Jevons, 1871;Pylyshyn & Storm, 1988;Rensink et al, 2000;VanRullen & Koch, 2003a; see also Gallace et al, 2006b, for the limitations affecting tactile numerosity judgments).…”

Section: Discussionmentioning

confidence: 99%

Do “mudsplashes” induce tactile change blindness?

Gallace

Tan

Spence

2007

Perception & Psychophysics

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The phenomenon of change blindness (the surprising inability of people to correctly perceive changes between consecutively presented displays), primarily reported in vision, has recently been shown to occur for positional changes presented in tactile displays as well. Here, we studied people's ability to detect changes in the number of tactile stimuli in successively presented displays composed of one to three stimuli distributed over the body surface. In Experiment 1, a tactile mask consisting of the simultaneous activation of all seven possible tactile stimulators was sometimes presented between the two to-be-discriminated tactile displays. In Experiment 2, a "mudsplash" paradigm was used, with a brief irrelevant tactile distractor presented at the moment of change of the tactile display. Change blindness was demonstrated in both experiments, thus showing that the failure to detect tactile change is not necessarily related to (1) the physical disruption between consecutive events, (2) the effect of masking covering the location of the change, or (3) the erasure or resetting of the information contained within an internal representation of the tactile display. These results are interpreted in terms of a limitation in the number of spatial locations/events that can be consciously accessed at any one time. This limitation appears to constrain change-detection performance, no matter the sensory modality in which the stimuli are presented.

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“…Desimone & Duncan, 1995), this failure may result in a lack of conscious access to information regarding such stimuli. This failure might be attributed to the competition that may exist among stimuli presented from different positions at the same time (see, e.g., Gallace et al, 2006b;Wright, Green, & Baker, 2000;cf. Desimone & Duncan, 1995;VanRullen & Koch, 2003), regardless of the sensory modality of the stimuli's presentation (see Hubbard et al, 2005, for the suggestion of an inextricable link between the neural substrates representing numerical and spatial information).…”

Section: Discussionmentioning

confidence: 99%