A Mismatch-Based Model for Memory Reconsolidation and Extinction in Attractor Networks

The processes of memory reconsolidation and extinction have received increasing attention in recent experimental research, as their potential clinical applications begin to be uncovered. A number of studies suggest that amnestic drugs injected after reexposure to a learning context can disrupt either of the two processes, depending on the behavioral protocol employed. Hypothesizing that reconsolidation represents updating of a memory trace in the hippocampus, while extinction represents formation of a new trace, we have built a neural network model in which either simple retrieval, reconsolidation or extinction of a stored attractor can occur upon contextual reexposure, depending on the similarity between the representations of the original learning and reexposure sessions. This is achieved by assuming that independent mechanisms mediate Hebbian-like synaptic strengthening and mismatch-driven labilization of synaptic changes, with protein synthesis inhibition preferentially affecting the former. Our framework provides a unified mechanistic explanation for experimental data showing (a) the effect of reexposure duration on the occurrence of reconsolidation or extinction and (b) the requirement of memory updating during reexposure to drive reconsolidation

Medical Student Use of Online Lectures: Exam Performance, Learning Styles, Achievement Motivation and Gender

Content delivery in the basic science curriculum is increasingly accomplished by lectures delivered online. The factors which draw some students to use online resources more than others are beginning to be explored. This project examined the relationship between entering medical students‘ online lecture use, exam performance, learning styles, achievement motive and gender. We assessed learning style preference, using the VARK measure, and achievement motive, using the Achievement Motive Scale, then analyzed their online lecture use in our gross anatomy course. Exam scores for males were significantly higher than those of females and a gender effect was apparent (ANOVA) with male use higher than female. Students with higher scores for visual learning viewed lectures more than students with other preferences. There was an effect of Achievement Motive on lecture usage. Students highly motivated to achieve success are also more likely to use lectures. There was no difference in use between students with high or low motivation to avoid failure. Overall, there was a distinct temporal pattern of lecture use by day of the week or by time of day and differences between genders in use by days of the week. We also found a significant effect of success motivation on the temporal pattern of use. Findings of our study suggest a relationship between students\u27 learning style, motivation and their online lecture use