Autobiographically Significant Concepts: More Episodic than Semantic in Nature? An Electrophysiological Investigation of Overlapping Types of Memory

A common assertion is that semantic memory emerges from episodic memory, shedding the distinctive contexts associated with episodes over time and/or repeated instances. Some semantic concepts, however, may retain their episodic origins or acquire episodic information during life experiences. The current study examined this hypothesis by investigating the ERP correlates of autobiographically significant (AS) concepts, that is, semantic concepts that are associated with vivid episodic memories. We inferred the contribution of semantic and episodic memory to AS concepts using the amplitudes of the N400 and late positive component, respectively. We compared famous names that easily brought to mind episodic memories (high AS names) against equally famous names that did not bring such recollections to mind (low AS names) on a semantic task (fame judgment) and an episodic task (recognition memory). Compared with low AS names, high AS names were associated with increased amplitude of the late positive component in both tasks. Moreover, in the recognition task, this effect of AS was highly correlated with recognition confidence. In contrast, the N400 component did not differentiate the high versus low AS names but, instead, was related to the amount of general knowledge participants had regarding each name. These results suggest that semantic concepts high in AS, such as famous names, have an episodic component and are associated with similar brain processes to those that are engaged by episodic memory. Studying AS concepts may provide unique insights into how episodic and semantic memory interact

Ariel - Volume 9 Number 2

Executive Editor Emily Wofford Business Manager Fredric Jay Matlin University News John Patrick Welch World News George Robert Coar Editorials Editor Steve Levine Features Mark Rubin Brad Feldstein Photo Rick Spade Circulation Victor Onufreiczuk Lee Wugofsk

WOSUB : a subchannel code for steady-state and transient thermal-hydraulic analysis of BWR fuel pin bundles. Volume II. User's Manual

WOSUB (Computer program).The WOSUB-codes are spin-offs and extensions of the MATTEO- code [ 2 ]. The series of reports describe WOSUB-I and WOSUB-II in their respective status as of July 31, 1977. This report is the second of a series of three reports describing the WOSUB code. It gives a detailed description of the input data, flow charts, and output, and contains the list- ings of WOSUB-I and WOSUB-II. For the purpose of future ex- tensions parameters, common blocks and variables used in the code are listed in full detail. WOSUB-I and WOSUB-II are subchannel computer codes for the steady-state and transient analysis of the thermal-hydraulic characteristics of Boiling Water Reactor (BWR) fuel rod bundles. Both codes are also applicable'to analyze PR bundles, especially when these are ducted--a situation which most often arises in experimental set-ups. The main difference between WOSUB-I and WOSUB-II is that the former is designed to analyze small bundles, whereas the latter is capable to handle symmetric sections of today's large- sized BWR bundles. In addition, WOSUB-II does not contain all of the additions made in WOSUB-I yet, because it is deemed appropriate to introduce these into the smaller code first, before they are implemented into the bigger one. Both codes are still in the stage of evolutionary develop- ment. Thus, changes are to be expected in the near future. There- fore, it should be noticed that this report reflects the develop- ment as of July 1977 only.opical report for Task 3 of the Nuclear Power Reactor Safety Research Program sponsored by New England Electric System, Northeast Utilities Service Co. under the M.I.T. Energy Laboratory Electric Power Program