Copyright (c) 2009 All rights reserved. http://works.bepress.com/anna_brooks Recent documents in Anna Brooks en-us Wed, 19 Aug 2009 21:41:28 PDT 3600 http://works.bepress.com/anna_brooks/16 http://works.bepress.com/anna_brooks/16 Tue, 09 Jun 2009 19:13:37 PDT Anna Brooks http://works.bepress.com/anna_brooks/14 http://works.bepress.com/anna_brooks/14 Tue, 09 Jun 2009 19:13:36 PDT Johansson (1973 Perception & Psychophysics 14 201 ^ 211) suggested that point-light displays that are staticöso-called `snapshots'öcontain little or no information about the actor or their action. Here we present data that suggest even naive observers can perceive such infor- mation from static point-light arrays. Observers were able, at rates better than chance, to discriminate the directions of facing of sagittally viewed static point-light walkers. The data show also that, without feedback, performances improved with experience. Our data have implications for assumptions made in designing experiments with point-light displays and for models of the neural mechanisms mediating biological motion perceptions. Russell J. Reid http://works.bepress.com/anna_brooks/15 http://works.bepress.com/anna_brooks/15 Tue, 09 Jun 2009 19:13:36 PDT Spatial neglect is a complex neurological syndrome in which patients appear to experience a variety of attentional deficits across sensory modalities. The syndrome does not involve impairment in sensory processing, nor in cortical processes involved in the primary sensory cortices (primary visual cortex, primary auditory cortex, and so on). Instead, the syndrome manifests following damage to a range of cortical regions centred around the lateral parietooccipital border in the right cortical hemisphere. The lateral parieto-occipital border contains a number of visual cortical processing areas, and visual inattention is a dominant feature of many patients neglect. Using the "tuning properties" of visual cortical cells in that area we have developed a tool that can be used to explore the nature of visual processes occurring in the neglected hemi-field, that will probe the level of processing at which those deficits first arise, and which can be used to examine a new treatment for neglect - prism adaptation. Our data illustrate the sensitivity of the tool and show that the stimuli used for testing do examine the cortical locus affected by prism adaptation. Rick van der Zwan http://works.bepress.com/anna_brooks/13 http://works.bepress.com/anna_brooks/13 Tue, 10 Mar 2009 19:35:13 PDT Anna Brooks http://works.bepress.com/anna_brooks/11 http://works.bepress.com/anna_brooks/11 Tue, 10 Mar 2009 19:35:12 PDT Russell J. Reid http://works.bepress.com/anna_brooks/12 http://works.bepress.com/anna_brooks/12 Tue, 10 Mar 2009 19:35:12 PDT Whittle Hannah http://works.bepress.com/anna_brooks/10 http://works.bepress.com/anna_brooks/10 Tue, 10 Mar 2009 19:35:11 PDT Lauren Bartsch http://works.bepress.com/anna_brooks/9 http://works.bepress.com/anna_brooks/9 Tue, 10 Mar 2009 17:47:31 PDT We describe a new illusion in which a single stationary stimulus appears to undergo coherent global motion. Contrast relationships between the stimulus elements suggest the illusion arises via processing of Off- and On-channel signals that remain independent until after passing through low-level motion detectors. We propose that patterns of activation resulting from biphasic temporal impulse response functions in the magnocellular pathway are the basis of the illusion, and describe a model to account for the illusory motion percept. Anna Brooks http://works.bepress.com/anna_brooks/8 http://works.bepress.com/anna_brooks/8 Tue, 10 Mar 2009 17:47:31 PDT We present evidence that grouping for luminance does not take precedence over the detection of bilaterally symmetrical patterns. Using single-axis and double-axis images, we found that element pairs within which luminance is held constant drive symmetry-detection mechanisms more effectively than pairs within which luminance varies. Moreover, the performance decrement observed for patterns defined by element pairs within which luminance varies is not specific to interchannel variation. Luminance variation within the ON and OFF channels has the same effect as variation between the channels on the performance of axis-orientation identification tasks. It is argued that this constitutes possible evidence for subchannels within the ON and OFF channels. One of the characteristics of the subchannels is that each processes only a limited range of luminance steps. The implications of this type of luminance processing for the detection of symmetry in the visual scene are discussed. Anna Brooks http://works.bepress.com/anna_brooks/7 http://works.bepress.com/anna_brooks/7 Tue, 10 Mar 2009 17:26:03 PDT The aim of these experiments was to assess the effect of an educational brochure on the ability of naive observers to discriminate skin cancers from benign lesions, and to investigate possible new strategies to assist observers in performing this task. A two-alternative forced choice paradigm was used to investigate the ability of observers to correctly identify different types of benign and malignant lesions before and after exposure to an educational brochure. The method of pair comparisons was used to assess the ability of observers to discriminate between benign and malignant lesions under different instruction conditions. Subjects were undergraduate students from Sydney University. An educational brochure did not facilitate the ability to correctly identify malignant lesions, and appeared to result in deterioration of performance in the identification of benign lesions. Similarly, observers were unable to discriminate between benign and malignant lesions on the basis of how dangerous they looked. However, judgements of lesions in terms of perceived distinctiveness resulted in relatively accurate discriminations between benign and malignant lesions. These data suggest current skin cancer detection strategies may be ineffective in improving the ability to visually identify benign and malignant lesions. Discriminating between lesions in terms of how distinctive they appear may form the basis of a new and effective strategy for the detection of skin cancer. Anna Brooks