Forgetting in short term memory : the effect of time

The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on August 19, 2009)Thesis (M.A.) University of Missouri-Columbia 2008.Forgetting in short-term memory has been studied extensively and yet no consensus has emerged to explain its cause. Two theories continue to provide competing explanations of forgetting in short-term memory: decay and interference. Decay presupposes that the memory trace for a set of stimuli to be remembered weakens in proportion to the amount of time that passes whereas interference posits one stimulus interacting with another as the cause of forgetting. Recent evidence has suggested that decay should no longer be considered a viable mechanism to explain forgetting; but the current set of studies provides compelling evidence to the contrary. Hence these studies argue that decay should not be abandoned.Includes bibliographical reference

Sequential Analysis of Trans-SNARE Formation in Intracellular Membrane Fusion

SM proteins stabilize cis-SNARE complexes leading to a specific preferred topology for trans-SNARE formation

Kynurenine–3–monooxygenase inhibition prevents multiple organ failure in rodent models of acute pancreatitis

Acute pancreatitis (AP) is a common and devastating inflammatory condition of the pancreas that is considered to be a paradigm of sterile inflammation leading to systemic multiple organ dysfunction syndrome (MODS) and death1,2 Acute mortality from AP-MODS exceeds 20%3 and for those who survive the initial episode, their lifespan is typically shorter than the general population4. There are no specific therapies available that protect individuals against AP-MODS. Here, we show that kynurenine-3-monooxygenase (KMO), a key enzyme of tryptophan metabolism5, is central to the pathogenesis of AP-MODS. We created a mouse strain deficient for Kmo with a robust biochemical phenotype that protected against extrapancreatic tissue injury to lung, kidney and liver in experimental AP-MODS. A medicinal chemistry strategy based on modifications of the kynurenine substrate led to the discovery of GSK180 as a potent and specific inhibitor of KMO. The binding mode of the inhibitor in the active site was confirmed by X-ray co-crystallography at 3.2 Å resolution. Treatment with GSK180 resulted in rapid changes in levels of kynurenine pathway metabolites in vivo and afforded therapeutic protection against AP-MODS in a rat model of AP. Our findings establish KMO inhibition as a novel therapeutic strategy in the treatment of AP-MODS and open up a new area for drug discovery in critical illness

Seven-year-olds allocate attention like adults unless working memory is overloaded

Previous studies have indicated that visual working memory performance increases with age in childhood, but it is not clear why. One main hypothesis has been that younger children are less efficient in their attention; specifically, they are less able to exclude irrelevant items from working memory to make room for relevant items. We examined this hypothesis by measuring visual working memory capacity under a continuum of five attention conditions. A recognition advantage was found for items to be attended as opposed to ignored. The size of this attention-related effect was adult-like in young children with small arrays, suggesting that their attention processes are efficient even though their working memory capacity is smaller than that of older children and adults. With a larger working memory load, this efficiency in young children was compromised. The efficiency of attention cannot be the sole explanation for the capacity difference

An assessment of fixed-capacity models of visual working memory

Visual working memory is often modeled as having a fixed number of slots. We test this model by assessing the receiver operating characteristics (ROC) of participants in a visual-working-memory change-detection task. ROC plots yielded straight lines with a slope of 1.0, a tell-tale characteristic of all-or-none mnemonic representations. Formal model assessment yielded evidence highly consistent with a discrete fixed-capacity model of working memory for this task