John Teague Calhoun

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Behavioral and neurophysiological studies suggest that the brain constructs different representations of space. Among these representations are personal and peripersonal space. Personal space refers to the space occupied by our bodies. Peripersonal space refers to the space surrounding our bodies, which can be reached by our limbs. How these two(More)
Extinction is thought to be due to a pathologically limited attentional capacity in which multiple stimuli cannot be processed simultaneously to conscious awareness. Patients with tactile extinction are aware of being touched on a contralesional limb, but seem unaware of similar contralesional touch if touched simultaneously on their ipsilesional limb. The(More)
We investigated tactile awareness in three patients with tactile extinction of stimuli located on contralesional somatotopic space. Contralesional tactile awareness was enhanced when they gazed to the left and when they moved their limbs. We suggest that personal somatotopic and peripersonal space are integrated by polymodal and sensorimotor links, which(More)
When patients with left-sided neglect are asked to bisect horizontal lines, they tend to place their marks to the right of the line's objective mid-point. However, when asked to bisect short lines they are either more accurate or paradoxically cross over and place their marks to the left of the objective mid-point. Previous explanations of the cross over(More)
Left-neglect patients bisect horizontal lines to the right of true center. Longer lines are bisected further to the right than shorter lines. This line-length effect might be explained by an increase in the rightward bias of attention because longer lines extend further ipsilesionally. Alternatively, neglect patients might be limited in their abilities to(More)
BACKGROUND AND OBJECTIVES Surgeons constantly struggle with the formation of condensation on the lens of a laparoscope, which prolongs procedures and reduces visibility of the abdominal cavity. The goal of this project was to build a device that would direct a flow of carbon dioxide (CO2) into an open chamber surrounding the lens of a laparoscope, acting to(More)
Vacuum pumps have been described as compressors for rarefied gases. For more than twenty-five years the scroll compressor principle has been used in designing vacuum pumps that do not rely on oil to provide their pumping action. The dry scroll vacuum pump has been particularly successful as a source of rough vacuum for analytical instruments such as(More)
SYLLABUS This course has two main objectives. First, we will examine the historical development of American political theory with an eye to see it, not as a unified trajectory of developing ideas about state, economy, and citizenship, but as a body of work influenced by multiple, sometimes conflicting, historical and theoretical traditions. Second, we will(More)
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