Publications by authors named "Callum D Dewar"

Military-civilian partnerships have built the foundation for US neurosurgery as we see it today. Each conflict throughout history has led to expansion within the field of neurosurgery, benefiting civilian patients and those in uniform. Despite the field's growth during wartime, military neurosurgical case volume declines during peacetime, and as a result, important knowledge gained is at risk of being lost.

View Article and Find Full Text PDF

How do we think about time? Converging lesion and neuroimaging evidence indicates that orbitofrontal cortex (OFC) supports the encoding and retrieval of temporal context in long-term memory, which may contribute to confabulation in individuals with OFC damage. Here, we reveal that OFC damage diminishes working memory for temporal order, that is, the ability to disentangle the relative recency of events as they unfold. OFC lesions reduced working memory for temporal order but not spatial position, and individual deficits were commensurate with lesion size.

View Article and Find Full Text PDF

Background: Vestibular compensatory eye movements provide visual fixation stabilization during head movement. The anatomic pathways mediating a normal horizontal vestibulo-ocular reflex (h-VOR), when lesioned, cause spontaneous nystagmus. While previous reports address the effect of convergence on different spontaneous nystagmus types, to our knowledge, a study of acute vestibular nystagmus suppression viewing near targets comparing patients with peripheral or central vestibular lesions has not been previously reported.

View Article and Find Full Text PDF
Article Synopsis
  • Medical malpractice lawsuits in the military have been limited for a long time because of a rule called the Feres Doctrine, established in 1950, which says active military members can't sue for malpractice.
  • This rule has been challenged more often recently, as many malpractice cases have been thrown out.
  • In 2020, a new law created a group to review and settle these medical malpractice claims in the military's healthcare system, marking the first big change to the Feres Doctrine in 70 years.
View Article and Find Full Text PDF

Decision making often requires making arbitrary choices ("picking") between alternatives that make no difference to the agent, that are equally desirable, or when the potential reward is unknown. Using event-related potentials we tested the effect of age on this common type of decision making. We compared two age groups: ages 18-25, and ages 41-67 on a masked-priming paradigm while recording EEG and EMG.

View Article and Find Full Text PDF

The ability to represent and select information in working memory provides the neurobiological infrastructure for human cognition. For 80 years, dominant views of working memory have focused on the key role of prefrontal cortex (PFC) [1-8]. However, more recent work has implicated posterior cortical regions [9-12], suggesting that PFC engagement during working memory is dependent on the degree of executive demand.

View Article and Find Full Text PDF