http://precedings.nature.com/users/f9c1dafae5dedfc43d5c0d5928836523/ Documents posted by David Burr Nature Publishing Group en Nature Precedings http://precedings.nature.com/images/header_logo.gif http://precedings.nature.com http://precedings.nature.com/documents/2792/version/1 We have recently suggested that numerosity is a primary sensory attribute, showing that it is strongly susceptible to adaptation. Here we use the Method of Single Stimuli (MSS) to show that observers can extract a running average of the numerosity of a succession of stimuli and hold it in mind for use as a standard of comparison for subsequent stimuli. Accuracy and precision of judgments are high and not reduced by potentially misleading variables like texture density or display area. http://precedings.nature.com/documents/2792/version/1 Fri, 16 Jan 2009 16:29:46 UTC Vision senses number directly hdl:10101/npre.2009.2792.1 2009-01-16 David C. Burr Nature Precedings 2009-01-16T16:29:46Z Manuscript Neuroscience http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/2675/version/1 Robust and versatile perception of the world is augmented considerably when information from our five separate sensory systems is combined. Much recent evidence has demonstrated near-optimal integration across senses, but it remains unclear at what level the integration occurs, at a "sensory" or "decisional" level. Here we show that non-informative "pedestal" motion stimuli in one sensory modality (vision or touch) selectively lowers thresholds in the other, to the same degree as pedestals in the same modality: strong evidence for functionally important cross-sensory integration at early levels of sensory processing. http://precedings.nature.com/documents/2675/version/1 Thu, 18 Dec 2008 13:45:36 UTC Cross-modal facilitation of visual and tactile motion hdl:10101/npre.2008.2675.1 2008-12-18 David Burr Nature Precedings 2008-12-18T13:45:36Z Manuscript Neuroscience http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/1353/version/1 Evidence exists for a non-verbal capacity to apprehend number, in humans1 (including infants2,3) and in other primates4-6. Here we show that perceived numerosity is susceptible to adaptation, along with primary visual properties of a scene like colour, contrast, size and speed. Apparent numerosity was decreased by adapting to large numbers of dots and increased by adapting to small numbers, the effect depended entirely on the numerosity of the adapter, not on contrast, size, orientation or pixel density, and occurred with very low adapter contrasts. We suggest that numerosity is also an independent primary visual property, not reducible to others like spatial frequency or density of texture7. http://precedings.nature.com/documents/1353/version/1 Tue, 20 Nov 2007 12:32:03 UTC A visual sense of number hdl:10101/npre.2007.1353.1 2008-04-22 David Burr Nature Precedings 2007-11-20T12:32:03Z Manuscript Neuroscience http://creativecommons.org/licenses/by/3.0/ http://precedings.nature.com/documents/1521/version/1 Several studies have shown that adults integrate visual and haptic information (and information from other modalities) in a statistically optimal fashion, weighting each sense according to its reliability. To date no studies have investigated when this capacity for cross-modal integration develops. Here we show that prior to eight years of age, integration of visual and haptic spatial information is far from optimal, with either vision or touch dominating totally, even in conditions where the dominant sense is far less precise than the other (assessed by discrimination thresholds). For size discrimination, haptic information dominates in determining both perceived size and discrimination thresholds, while for orientation discrimination vision dominates. By eight-ten years, the integration becomes statistically optimal, like adults. We suggest that during development, perceptual systems require constant recalibration, for which cross-sensory comparison is important. Using one sense to calibrate the other precludes useful combination of the two sources. http://precedings.nature.com/documents/1521/version/1 Wed, 16 Jan 2008 16:00:34 UTC Young children do not integrate visual and haptic information hdl:10101/npre.2008.1521.1 2008-01-16 David C. Burr Nature Precedings 2008-01-16T16:00:34Z Manuscript Neuroscience http://creativecommons.org/licenses/by/3.0/