The journal of neuroscience : the official journal of the Society for Neuroscience.

The authors conceptualize these memory systems from both behavioural and neurobiological perspectives, guided by three related principles: * First, that our understanding of a wide range of memory phenomena can be advanced by breaking down memory into multiple forms with different operating characteristics. * Second, that different forms of memory representation are supported by distinct brain pathways with circuitry and neural coding properties. * Third, that the contributions of different brain systems can be compared and contrasted by distinguishing between dedicated (or specific) and elaborate (or general) memory systems. A primary goal of this work is to relate the neurobiological properties of dedicated and elaborate systems to their neuropsychological counterparts, and in so doing, account for the phenomenology of memory, from conditioning to conscious recollection.

From Conditioning to Conscious Recollection Memory Systems of the Brain. Oxford Psychology Series, Volume 35.

What manner of organization is the National Bureau of Economic Research? How does it select research topics? Who does the work and what kind of tasks do they perform? Where do the funds come from? How does the National Bureau safeguard the scientific quality of its findings? How are the results disseminated? Visitors to the National Bureau often ask these and similar questions; perhaps the answers will be of interest to readers of the American Statistician. The National Bureau of Economic Research is a private non-profit corporation, formed, according to its charter, "to conduct, or assist in the making of exact and impartial investigations in the field of economic, social and industrial science, and to this end to cooperate with governments, universities, learned societies, and individuals." Hence it is not a government agency, nor an adjunct of a university, nor does it sell research services. The revenue from the only products it does sell, publications, barely covers the printing costs. Its funds are contributed by philanthropic foundations, by trade and professional organizations, by business concerns, trade unions, and individuals. Contributions are usually on a yearly basis, but some grants cover several years. Some of the funds are earmarked for specific studies; the balance goes to support a general program of research. The National Bureau is governed by a Board of Directors numbering about thirty, selected to represent various institutions and diverse points of view on economic problems. Over the years since the Bureau was founded in 1920 this body of men has made a significant contribution to the development of scientific inquiry in economics, both within the National Bureau and outside. Such outstanding economists as Wesley C. Mitchell, George E. Roberts, Allyn A. Young, Edwin F. Gay, Thomas S. Adams, and John R. Commons have been among its members. At the present time professors from a dozen universities are on the Board. Also, Directors from each of the following organizations are elected: American Statistical Association, American Economic Association, American Farm Economic Association, Economic History Association, American Institute of Accountants, American Management Association, Congress of Industrial Organizations, and American Federation of Labor. Finally, there is a group of Directors at Large, men from varied walks of life with an abiding interest in economic research. The Board serves an important function not only in shaping the broad lines of the research program but also in safeguarding the quality of the results. Matters of policy requiring prompt action are handled by an Executive Committee of eleven, elected by the Board from its membership. Arthur F. Burns, the Director of Research, is the member of the Committee who is directly responsible for the research program. The members of the research staff, numbering about twenty-five, direct the individual studies, and are aided in their work by upwards of forty-five research assistants. A staff of typists, bookkeepers, mimeograph operators, etc., brings the total payroll of the National Bureau to roughly a hundred persons. William J. Carson, the Executive Director, handles the Bureau's finances, accounts, and other administrative matters. Not all the employees of the National Bureau work at the main office at 1819 Broadway, New York City. DuLr Financial Research Program is housed at "Hillside," an estate about 10 miles north of Manhattan overlooking the HuLdson River. Other National BureauL investigators are to be fotund at various universities throughout the United States, since cooperative arrangements are maintained with a number of universities that permit their facultv members to engage in National Butreau studies. Government agencies, too, cooperate in similar ways. Such cooperative relationships are a vital feature of our work, and we try to foster them in many ways. The growing acceptance on the part of universities of the view that research is part of the job of a faculty member has helped to make these efforts productive. For example, for a number of years we have appointed promising young men or women holding university positions as Research Associates for one year. The objective is to enable scholars to pursue their research interests in fields in which the National Bureau also has an interest. Since 1930 twenty-six Research Associates, coming from eighteen American colleges or universities and two foreign universities, have been appointed under the plan. The work of several committees is another example of cooperation for the purpose of advancing research. Two committees, one on financial and the other on fiscal research, help to guide our studies in these areas. They are composed of experts from universities, government agencies, and private business. In 1935 the Universities-National Bureau Committee was established for the express purpose of promoting contact

The National Bureau of Economic Research

The third way.

https://nmr.mgh.harvard.edu/~bradd/dickerson_neuropsychopharmacologyreviews_2009.pdf

The Episodic Memory System: Neurocircuitry and Disorders

We provide evidence that decisions are made by consulting memories for individual past experiences, and that this process can be biased in favour of past choices using incidental reminders. First, in a standard rewarded choice task, we show that a model that estimates value at decision-time using individual samples of past outcomes fits choices and decision-related neural activity better than a canonical incremental learning model. In a second experiment, we bias this sampling process by incidentally reminding participants of individual past decisions. The next decision after a reminder shows a strong influence of the action taken and value received on the reminded trial. These results provide new empirical support for a decision architecture that relies on samples of individual past choice episodes rather than incrementally averaged rewards in evaluating options and has suggestive implications for the underlying cognitive and neural mechanisms.

/pdf/reminders-of-past-choices-bias-decisions-for-reward-in-1cynnobgu9.pdf

Reminders of past choices bias decisions for reward in humans

The essential role of the medial temporal lobe (MTL) in long-term memory for individual events is well established, yet important questions remain regarding the mnemonic functions of the component structures that constitute the region. Within the hippocampus, recent functional neuroimaging findings suggest that formation of new memories depends on the dentate gyrus and the CA3 field, whereas the contribution of the subiculum may be limited to retrieval. During encoding, it has been further hypothesized that structures within MTL cortex contribute to encoding in a content-sensitive manner, whereas hippocampal structures may contribute to encoding in a more domain-general manner. In the current experiment, high-resolution fMRI techniques were utilized to assess novelty and subsequent memory effects in MTL subregions for two classes of stimuli-faces and scenes. During scanning, participants performed an incidental encoding (target detection) task with novel and repeated faces and scenes. Subsequent recognition memory was indexed for the novel stimuli encountered during scanning. Analyses revealed voxels sensitive to both novel faces and novel scenes in all MTL regions. However, similar percentages of voxels were sensitive to novel faces and scenes in perirhinal cortex, entorhinal cortex, and a combined region comprising the dentate gyrus, CA2, and CA3, whereas parahippocampal cortex, CA1, and subiculum demonstrated greater sensitivity to novel scene stimuli. Paralleling these findings, subsequent memory effects in perirhinal cortex were observed for both faces and scenes, with the magnitude of encoding activation being related to later memory strength, as indexed by a graded response tracking recognition confidence, whereas subsequent memory effects were scene-selective in parahippocampal cortex. Within the hippocampus, encoding activation in the subiculum correlated with subsequent memory for both stimulus classes, with the magnitude of encoding activation varying in a graded manner with later memory strength. Collectively, these findings suggest a gradient of content sensitivity from posterior (parahippocampal) to anterior (perirhinal) MTL cortex, with MTL cortical regions differentially contributing to successful encoding based on event content. In contrast to recent suggestions, the present data further indicate that the subiculum may contribute to successful encoding irrespective of event content.

/pdf/high-resolution-fmri-of-content-sensitive-subsequent-memory-osczmqa1dq.pdf

High-resolution fmri of content-sensitive subsequent memory responses in human medial temporal lobe

How does experience inform decisions? In episodic sampling, decisions are guided by a few episodic memories of past choices. This process can yield choice patterns similar to model-free reinforcement learning; however, samples can vary from trial to trial, causing decisions to vary. Here we show that context retrieved during episodic sampling can cause choice behavior to deviate sharply from the predictions of reinforcement learning. Specifically, we show that, when a given memory is sampled, choices (in the present) are influenced by the properties of other decisions made in the same context as the sampled event. This effect is mediated by fMRI measures of context retrieval on each trial, suggesting a mechanism whereby cues trigger retrieval of context, which then triggers retrieval of other decisions from that context. This result establishes a new avenue by which experience can guide choice and, as such, has broad implications for the study of decisions.

/pdf/reinstated-episodic-context-guides-sampling-based-decisions-5f1tj3obcj.pdf

Reinstated episodic context guides sampling-based decisions for reward

Behavior may be generated on the basis of many different kinds of learned contingencies. For instance, responses could be guided by the direct association between a stimulus and response, or by sequential stimulus-stimulus relationships (as in model-based reinforcement learning or goal-directed actions). However, the neural architecture underlying sequential predictive learning is not well understood, in part because it is difficult to isolate its effect on choice behavior. To track such learning more directly, we examined reaction times (RTs) in a probabilistic sequential picture identification task in healthy individuals. We used computational learning models to isolate trial-by-trial effects of two distinct learning processes in behavior, and used these as signatures to analyse the separate neural substrates of each process. RTs were best explained via the combination of two delta rule learning processes with different learning rates. To examine neural manifestations of these learning processes, we used functional magnetic resonance imaging to seek correlates of time-series related to expectancy or surprise. We observed such correlates in two regions, hippocampus and striatum. By estimating the learning rates best explaining each signal, we verified that they were uniquely associated with one of the two distinct processes identified behaviorally. These differential correlates suggest that complementary anticipatory functions drive each region's effect on behavior. Our results provide novel insights as to the quantitative computational distinctions between medial temporal and basal ganglia learning networks and enable experiments that exploit trial-by-trial measurement of the unique contributions of both hippocampus and striatum to response behavior.

/pdf/dissociating-hippocampal-and-striatal-contributions-to-2u6rl2hi8l.pdf

Dissociating hippocampal and striatal contributions to sequential prediction learning.

http://aaron.bornstein.org/cv/pubs/2011_bd_coin.pdf

Aaron M. Bornstein

Papers

Reminders of past choices bias decisions for reward in humans

High-resolution fmri of content-sensitive subsequent memory responses in human medial temporal lobe

Reinstated episodic context guides sampling-based decisions for reward

Dissociating hippocampal and striatal contributions to sequential prediction learning.

Multiplicity of control in the basal ganglia: computational roles of striatal subregions.