5 research outputs found
Experience-Dependent Changes in Excitatory and Inhibitory Receptor Subunit Expression in Visual Cortex
Experience-dependent development of visual cortex depends on the balance between excitatory and inhibitory activity. This activity is regulated by key excitatory (NMDA, AMPA) and inhibitory (GABAA) receptors. The composition of these receptors changes developmentally, affecting the excitatory–inhibitory (E/I) balance and synaptic plasticity. Until now, it has been unclear how abnormal visual experience affects this balance. To examine this question, we measured developmental changes in excitatory and inhibitory receptor subunits in visual cortex following normal visual experience and monocular deprivation. We used Western blot analysis to quantify expression of excitatory (NR1, NR2A, NR2B, GluR2) and inhibitory (GABAAα1, GABAAα3) receptor subunits. Monocular deprivation promoted a complex pattern of changes in receptor subunit expression that varied with age and was most severe in the region of visual cortex representing the central visual field. To characterize the multidimensional pattern of experience-dependent change in these synaptic mechanisms, we applied a neuroinformatics approach using principal component analysis. We found that monocular deprivation (i) causes a large portion of the normal developmental trajectory to be bypassed, (ii) shifts the E/I balance in favor of more inhibition, and (iii) accelerates the maturation of receptor subunits. Taken together, these results show that monocularly deprived animals have an abnormal balance of the synaptic machinery needed for functional maturation of cortical circuits and for developmental plasticity. This raises the possibility that interventions intended to treat amblyopia may need to address multiple synaptic mechanisms to produce optimal recovery
Novel application of principal component analysis to understanding visual cortical development
Novel application of principal component analysis to understanding visual cortical development
The Role of Interest and Images in Slideware Presentations
With the advent of technologies that allow lecturers to develop presentations using software such as Microsoft PowerPoint, Apple Keynote, and OpenOffice Impress (referred to generically here as "slideware"), lectures and meetings are beginning to resemble cinematic experiences rather than the text filled transactions that have been the norm for the last decade. Unfortunately, there has been little research on slideware use. Furthermore, literature on this topic indicates that lectures typically do little to encourage elaborative thinking. To address this gap in the literature, we tested 90 participants who each viewed a lecture on the visual system that consisted of three different styles of presentation: (1) Image Congruent: presenting images that were relevant to the target information, (2) Image Incongruent: presenting images that were relevant to the narration but not the target information and, (3) Text Based: presenting text summaries of the narration. Throughout each of these conditions, participants provided ratings of interest and then completed a quiz to measure recognition, recall and transfer. Our results revealed that participants were more interested in the image-rich slides than bullet points, and that accuracy (but not interest) depended on whether the images were relevant to the content of the lecture or not. Crown Copyright (C) 2010 Published by Elsevier Ltd. All rights reserved