Are There Multiple Kinds of Episodic Memory? An fMRI Investigation Comparing Autobiographical and Recognition Memory Tasks

What brain regions underlie retrieval from episodic memory? The bulk of research addressing this question has relied upon laboratory-based recognition memory. Another, less dominant tradition has employed autobiographical methods, whereby people recall events from their lifetime, often after being cued with words or pictures. Previous research comparing regions underlying successful memory retrieval between these two methodological approaches has shown mixed results. To examine the neural processes underlying recognition memory for materials encountered in the laboratory and autobiographical memory, we conducted a within-subject study using fMRI. We showed participants indoor and outdoor scenes under two types of instructions: In the lab-based recognition condition we asked participants to report whether they remembered the scene from the prior study phase. In the autobiographical condition, participants were asked to report whether the scene reminded them of a specific event in their lives. We compared the BOLD activity of successful retrieval of lab-based recognition memory (hits) to the reported successful retrieval of autobiographical memory. We found many regions differentially activated during the two tasks. Critically, autobiographical retrieval activated the default mode network more whereas recognition hits engaged two subnetworks of the frontoparietal network more. The finding of areas differentially activated during the two types of memory retrieval suggests that successful retrieval in the form of recognition of recently-studied items and successful retrieval in the form of stimulus-evoked autobiographical memories engage different processes and are dissociable

Levels of processing and the parietal memory network

The parietal memory network (PMN) is a functional brain network that has been recently described through the convergence of task-based fMRI and resting-state functional MRI studies (Gilmore et al., 2015). The networkճ characteristic encoding/retrieval flip (deactivation at encoding and activation at later retrieval, discussed by Gilmore and colleagues) and its manifestation of a negative subsequent memory effect (greater deactivation at encoding for items that will later be recognizedѩ.e., subsequent hitsѴhan for those that will notѳubsequent misses) (Cabeza et al., 2004; Daselaar, Prince, & Cabeza, 2004; De Chastelaine & Rugg, 2014; Elman, Rosner, Cohn-Sheehy, Cerreta, & Shimamura, 2013; Kim, 2011; Otten & Rugg, 2001) and other memory-related contrasts suggest possible ties to effective encoding of memory. This study sought to use task-based functional MRI to further investigate this tie between the PMN and encoding through the use of the levels of processing paradigm (Craik & Lockhart, 1972; Craik & Tulving, 1975). Specifically, I hypothesized that the PMNѷhich demonstrates the negative subsequent memory effectѷould deactivate more for conditions that lead to more effective encoding such as a deeper level of processing. Partial support for greater deactivation in the PMN for deeper processing was observed in two of the three regions that form the network (specifically within precuneus and mid cingulate): Precuneus (and to a lesser extent) mid cingulate deactivated for deeper, semantic processing than for the more shallow orthographic processing. However, the two regions did not show differential activity between semantic and phonological processing (presumably shallower than semantic processing), despite behavioral differences; The third region of the network, PIPL, did not show a consistent levels of processing effect in the univariate analyses, nor did it show the negative subsequent memory effect despite all other PMN regions showing the effect. Linear-mixed effect modeling of PMN regions showed that trial-by-trial variation in levels of BOLD activity in precuneus and mid cingulate predicted subsequent memory, above and beyond the level of processing manipulation as well as contribution from left inferior frontal gyrus (IFG), a region consistently identified in subsequent memory studies (Kim, 2011). Attempts to use multivariate pattern analysis to classify subsequent memory using only individual PMN regions led to above chance classification (hit or miss) for all PMN regions. The ability to predict subsequent memory using only activity from PMN regions (and beyond the contribution of left IFG) supports the role of the PMN in encoding, showing that a sufficient level of deactivation in PMN regions is associated with successful encoding regardless of the level of processing. Overall, the study supported the conclusion that two members of the PMNѴhe precuneus and mid cingulateѣontribute to effective encoding of memory

Predicting Stock Volatility Using After-Hours Information

We use realized volatilities based on after hours high frequency returns to predict next day volatility. We extend GARCH and long-memory forecasting models to include additional information: the whole night, the preopen, the postclose realized variance, and the overnight squared return. For four NASDAQ stocks (MSFT, AMGN, CSCO, and YHOO) we find that the inclusion of the preopen variance can improve the out-of-sample forecastability of the next day conditional day volatility. Additionally, we find that the postclose variance and the overnight squared return do not provide any predictive power for the next day conditional volatility. Our findings support the results of prior studies that traders trade for non-information reasons in the postclose period and trade for information reasons in the preopen period.

City-like Settlement to Industrial City: A Case of Urban Transformation in Huwei Township

[EN] City-like Settlement (German: Teilweise Stadtähnliche Siedlungen) (Schwarz, 1989; Sorre, 1952) plays an important role in the course of civilization, especially the development of industrial cities. Accordingly, this study utilizes Town-Plan Analysis (Conzen, 1960) to deconstruct the relationships between industrialization and settlement formation in order to illustrate the common origin of cities in Taiwan as a result of the emerging economy at the turn of the 20th century. The industrial city of Huwei, known as the “sugar city” with largest yields of cane sugar in Taiwan, had the largest-scale sugar refinery in pre-war East Asia (Williams, 1980). The city has grown and transformed with the factory during the four phases of morphological periods, which began at the establishment of the sugar refinery and worker housing in the middle of the fertile flooding plain in western Taiwan. The spatial arrangement was directed to operational and management efficiency, characterized by the simple grids and hierarchy of layout along the riverside. As the industry enlarged, the new urban core was planned to support the original settlement with shophouses accumulated in the small grids. Followed by postwar modernism (Schinz, 1989), the urban planning again extended the city boundary with larger and polygonal blocks. In the fourth phase, however, the sugar refinery downsized, leading to the conversion of the worker housing and the merging of the factory and the city that slowly brought to its present shape. The morphological process results in the concentric structure from the sugar refinery, providing valuable references for the preservation of the sugar industry townscape, and unveils the influence of industrialization as well as the special urban development pattern in Taiwan.Chen, C.; Chen, C. (2018). City-like Settlement to Industrial City: A Case of Urban Transformation in Huwei Township. En 24th ISUF International Conference. Book of Papers. Editorial Universitat Politècnica de València. 833-841. https://doi.org/10.4995/ISUF2017.2017.5923OCS83384