Learn More
For nonhumans, it has been shown that the hippocampus (HPC) is critical for spatial memory. We tested patients with unilateral HPC resections on a virtual analogue of a classic spatial task to assess HPC functioning in nonhumans: the Morris water task. We found that when humans are required to use spatial cues to navigate to a hidden escape platform in a(More)
The DO Collaboration reports on a search for the standard model top quark in pp collisions at +s = 1.8 TeV at the Fermilab Tevatron with an integrated luminosity of approximately 50 pb '. We have searched for tt production in the dilepton and single-lepton decay channels with and without tagging of b-quark jets. We observed 17 events with an expected(More)
In many mammalian species, it is known that males and females differ in place learning ability. The performance by men and women is commonly reported to also differ, despite a large amount of variability and ambiguity in measuring spatial abilities. In the non-human literature, the gold standard for measuring place learning ability in mammals is the Morris(More)
Using a within-subjects design, rats were trained on two place-memory problems and five object-discrimination problems at different intervals prior to receiving either ibotenate lesions of the hippocampal formation or sham surgery. Places # 1 and 2 were fixed-platform water-maze tasks that were run in different rooms and they were learned during the 14th(More)
We review evidence from experiments conducted in our laboratory on retrograde amnesia in rats with damage to the hippocampal formation. In a new experiment reported here, we show that N-methyl-D-aspartate (NMDA)-induced hippocampal damage produced retrograde amnesia for both hidden platform and two-choice visible platform discriminations in the Morris water(More)
The hippocampus has long been implicated in spatial memory, from work in rodents to imaging and brain lesion studies in humans. However, recent evidence has pointed to the recruitment of areas outside the hippocampus proper on spatial memory tasks, including the parahippocampal gyrus and precuneus, possibly suggesting a more focused role for the hippocampus(More)
It is becoming common to collect data from multiple functional magnetic resonance imaging (fMRI) paradigms on a single individual. The data from these experiments are typically analyzed separately and sometimes directly subtracted from one another on a voxel-by-voxel basis. These comparative approaches, although useful, do not directly attempt to examine(More)
BACKGROUND Previous neuroimaging studies of working memory (WM) in schizophrenia, typically focusing on dorsolateral prefrontal cortex, yield conflicting results, possibly because of varied choice of tasks and analysis techniques. We examined neural function changes at several WM loads to derive a more complete picture of WM dysfunction in schizophrenia. (More)
Investigations of working memory tend to focus on the retention of verbal information. The present experiments were designed to characterize the active maintenance rehearsal process used in the retention of visuospatial information. Rhesus monkeys (Macaca mulatta; N = 6) were tested as well as humans (total N = 90) because these nonhuman primates have(More)
Different tasks are often used to assess spatial memory in humans compared to nonhumans. In order to bridge this paradigmatic gap, we used a within-subject design to test 61 undergraduates on three spatial memory tasks. One of these tasks, the Vanderberg 3D mental rotation task, is classically used to assess spatial memory in humans. The other two tests are(More)