The experiments in this proposal share two basic themes. The first is that visual texture stimuli may be used to probe the initial visual coding of images and image sequences. The second theme is to relate all of our work to a basic 4-stage, multiple channel model, the """"""""back-pocket model of texture segregation."""""""" Each channel consists of (1) an initial linear spatial filter, (2) a nonlinearity, and (3) a second linear filter. These channels feed (4) a combination rule or linking hypothesis that yields a response or prediction of performance in a given task. Our work attempts to confirm this model, characterize its mechanisms, analyze its capabilities, and relate it to the underlying physiology. This proposal has three major aims.
The first aim concerns the coding and appearance of natural textures. We investigate whether human texture coding is matched to the statistics of natural textures and the degree to which observers can estimate physical characteristics of textures independent of viewing conditions.
The second aim i nvestigates how the back-pocket model channels are used for the identification of texture defined objects and includes further investigations of the structure and selectivity of back-pocket model channels.
The third aim i s to investigate the cortical implementation of texture or 2nd-order channels using fMRI to measure responses to and adaptation to texture modulations. ? ?
|Saarela, Toni P; Landy, Michael S (2015) Integration trumps selection in object recognition. Curr Biol 25:920-7|
|Westrick, Zachary M; Henry, Christopher A; Landy, Michael S (2013) Inconsistent channel bandwidth estimates suggest winner-take-all nonlinearity in second-order vision. Vision Res 81:58-68|
|Wang, Helena X; Heeger, David J; Landy, Michael S (2012) Responses to second-order texture modulations undergo surround suppression. Vision Res 62:192-200|
|Barbot, Antoine; Landy, Michael S; Carrasco, Marisa (2012) Differential effects of exogenous and endogenous attention on second-order texture contrast sensitivity. J Vis 12:|
|Saarela, Toni P; Landy, Michael S (2012) Combination of texture and color cues in visual segmentation. Vision Res 58:59-67|
|Hallum, Luke E; Landy, Michael S; Heeger, David J (2011) Human primary visual cortex (V1) is selective for second-order spatial frequency. J Neurophysiol 105:2121-31|
|Girshick, Ahna R; Landy, Michael S; Simoncelli, Eero P (2011) Cardinal rules: visual orientation perception reflects knowledge of environmental statistics. Nat Neurosci 14:926-32|
|Barbot, Antoine; Landy, Michael S; Carrasco, Marisa (2011) Exogenous attention enhances 2nd-order contrast sensitivity. Vision Res 51:1086-98|
|Larsson, Jonas; Heeger, David J; Landy, Michael S (2010) Orientation selectivity of motion-boundary responses in human visual cortex. J Neurophysiol 104:2940-50|
|Oruc, Ipek; Landy, Michael S (2009) Scale dependence and channel switching in letter identification. J Vis 9:4.1-19|
Showing the most recent 10 out of 17 publications