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Humans are remarkably adept at recognizing objects across a wide range of views. A notable exception to this general rule is that turning a face upside down makes it particularly difficult to recognize. This striking effect has prompted speculation that inversion qualitatively changes the way faces are processed. Researchers commonly assume that configural(More)
To better understand how the visual system makes use of information across spatial scales when identifying different kinds of complex patterns, we measured human and ideal contrast identification thresholds to estimate identification efficiency for 1- and 2-octave wide band-pass filtered letters and faces embedded in 2-D dynamic Gaussian noise. Varying(More)
The visual system is constantly faced with the problem of identifying partially occluded objects from incomplete images cast on the retinae. Phenomenologically, the visual system seems to fill in missing information by interpolating illusory and occluded contours at points of occlusion, so that we perceive complete objects. Previous behavioural [1] [2] [3](More)
When you see a person's face, how do you go about combining his or her facial features to make a decision about who that person is? Most current theories of face perception assert that the ability to recognize a human face is not simply the result of an independent analysis of individual features, but instead involves a holistic coding of the relationships(More)
Performance in perceptual tasks often improves with practice. This effect is known as 'perceptual learning,' and it has been the source of a great deal of interest and debate over the course of the last century. Here, we consider the effects of perceptual learning within the context of signal detection theory. According to signal detection theory, the(More)
A constant problem faced by the visual system is the identification of partly occluded objects within the visual scene. Recent experiments have demonstrated that the visual system engages in a process of visual completion, where the hidden parts of objects are filled into the visual representation. Recent experiments have also suggested that there may be a(More)
The bubbles method is a recently developed variant of reverse correlation methods that have been used in psychophysics and physiology. We show mathematically that for the broad and important class of noisy linear observers, the bubbles method recovers much less information about how observers process stimuli than reverse correlation does. We also show(More)
Much recent research has aimed to establish whether visual working memory (WM) is better characterized by a limited number of discrete all-or-none slots or by a continuous sharing of memory resources. To date, however, researchers have not considered the response-time (RT) predictions of discrete-slots versus shared-resources models. To complement the past(More)
After observers see an object or pattern, their visual memory of what they have seen decays slowly over time. Nearly all current theories of vision assume that decay of short-term memory occurs because visual representations are progressively and randomly corrupted as time passes. We tested this assumption using psychophysical noise-masking methods, and we(More)