Allocentric spatial memory was studied in dogs of varying ages and sources using a landmark discrimination task. The primary goal of this study was to develop a protocol to test landmark discrimination learning in the dog. Using a modified version of a landmark test developed for use in monkeys, we successfully trained dogs to make a spatial discrimination on the basis of the position of a visu...

Hyperspectral anomaly detection is one of the main challenging topics in both military and civilian fields. The spectral information contained in a hyperspectral cube provides a high ability for anomaly detection. In addition, the costly spatial information of adjacent pixels such as texture can also improve the discrimination between anomalous targets and background. Most studies miss the wort...

* This research was supported by NIMH RO1 MH62480 and NSF BCS 00-91757, both awarded to JPS. Abstract – The Dynamic Field Theory (DFT) has been used to account for spatial recall biases in children and adults. This paper extends the DFT to a second spatial working memory task, position discrimination. The DFT captures details of adults’ discrimination performance, as well as predicting developm...

We examined the effects of luminance contrast and spatial frequency on chromaticity discrimination of grating bars. Alternate bars of gratings were filled with light of a standard wavelength and light that could be varied in wavelength. The observer set the variable bars to match the standard bars in hue. Discrimination, as measured by the standard deviation of the matches, decreased as spatial...

Recently we reported that hyperacuity thresholds for separation-discrimination tasks were not smooth functions of spatial variables but rather were regularly segmented with sharp transitions between the segments. In this study we have measured the orientation dependence of two tasks involving visual hyperacuity, the discrimination of spatial frequencies and the discrimination of vernier offsets...

Models proposed to account for reference frame effects in spatial cognition often account for performance in some tasks well, but fail to generalize to other tasks. Here, we demonstrate that a new process account of spatial working memory--the dynamic field theory (DFT)--can bridge the gap between perceptual and memory processes in position discrimination and spatial recall, highlighting that t...

Recent theories posit that adult neurogenesis supports dentate gyrus pattern separation and hence is necessary for some types of discrimination learning. Using an inducible transgenic mouse model, we investigated the contribution of adult-born neurons to spatial and nonspatial touch-screen discriminations of varying levels of difficulty. Arresting neurogenesis caused a modest but statistically ...

The human temporo-parieto-occipital junction is an extrastriate visual area that may mediate motion vision processing. We determined if transcranial magnetic stimulation (TMS) delivered over this extrastriate area would degrade motion discrimination, similar to the transient decrease in spatial acuity observed when TMS is delivered over striate cortex. TMS was delivered 50-250 msec after the on...

Behavioral and neurophysiological studies in macaque monkeys suggest a role of the inferior temporal cortex in pattern discrimination and visual memory. To determine whether this cortical area is also involved in human short-term visual memory, we measured spatial frequency discrimination thresholds for sequentially presented stimuli in 17 patients with unilateral, postoperative focal damage to...

Sumita, S., Prescott, N.B., Broom, D.M., Wathes, C.M. and Phillips, C.J.C. 2013. Visual discrimination learning and spatial acuity in sheep. Applied Animal Behaviour Science, 147, 104-111. doi:10.1016/j.applanim.2013.04.012 Pre-publication copy Visual discrimination learning and critical spatial acuity in sheep Sumita Sugnaseelan, Neville B. Prescott, Donald M. Broom, Christopher M. Wathes and ...