Previous experiments have shown a serial-position effect (SPE) in paired-associate (PA) learning where the pairs contained stimuli pre- viously learned in serial order. The present experiment extended the number of pairs from 10 to 14. Pairs containing stimuli from terminal serial positions were learned with significantly fewer errors than pairs whose stimuli derived from central positions. The latter produced a dip in the PA error distribution suggesting the presence of sequential associations in SL (...) between items occupying central positions. (shrink)

Prior knowledge structures (or schemas) confer multiple behavioral benefits. First, when we encounter information that fits with prior knowledge structures, this information is generally better learned and remembered. Second, prior knowledge can support prospective planning. In humans, memory enhancements related to prior knowledge have been suggested to be supported, in part, by computations in prefrontal and medial temporal lobe cortex. Moreover, animal studies further implicate a role for the hippocampus in schema-based facilitation (...) and in the emergence of prospective planning signals following new learning. To date, convergence across the schema-enhanced learning and memory literature may be constrained by the predominant use of hippocampally dependent spatial navigation paradigms in rodents, and non-spatial list-based learning paradigms in humans. Here, we targeted this missing link by examining the effects of prior knowledge on human navigational learning in a hippocampally dependent virtual navigation paradigm that closely relates to foundational studies in rodents. Outside the scanner, participants overlearned Old Paired Associates (OPA – item-location associations) in multiple spatial environments, and they subsequently learned New Paired Associates (NPA – new item-location associations) in the environments while undergoing fMRI. We hypothesized that greater OPA knowledge precision would positively affect NPA learning, and that the hippocampus would be instrumental in translating this new learning into prospective planning of navigational paths to NPA locations. Behavioral results revealed that OPA knowledge predicted one-shot learning of NPA locations, and neural results indicated that one-shot learning was predicted by the rapid emergence of performance-predictive prospective planning signals in hippocampus. Prospective memory relationships were not significant in parahippocampal cortex and were marginally dissociable from the primary hippocampal effect. Collectively, these results extend understanding of how schemas impact learning and performance, showing that the precision of prior spatial knowledge is important for future learning in humans, and that the hippocampus is involved in translating this knowledge into new goal-directed behaviors. (shrink)

Paired associative stimulation at the spinal cord has been shown to increase muscle force and dexterity by strengthening the corticomuscular connection, through spike timing dependent plasticity. Typically, transcranial magnetic stimulation and transcutaneous peripheral nerve electrical stimulation are often used in spinal PAS. PNS targets superficial nerve branches, by which the number of applicable muscles is limited. Alternatively, a muscle can be activated by positioning the stimulation electrode on the “motor point”, which is the most sensitive location of a muscle (...) to electrical stimulation. Although this can increase the number of applicable muscles for spinal PAS, nobody has tested whether MPS can be used for the spinal PAS to date. Here we investigated the feasibility of using MPS instead of PNS for spinal PAS. Ten healthy male individuals received spinal PAS on two separate days with different stimulation timings expected to induce facilitation of corticospinal excitability or no effect on the soleus. The motor evoked potentials response curve in the soleus was measured prior to the spinal PAS, immediately after and at 10, 20, 30 min post-intervention as a measure of corticospinal excitability. The post-intervention MEP response curve areas were larger in the REAL condition than the CONTROL conditions. Further, the post-intervention MEP response curve areas were significantly larger than pre-intervention in the REAL condition but not in the CONTROL condition. We conclude that MPS can facilitate corticospinal excitability through spinal PAS. (shrink)

continent. 1.2 (2011): 141-144. This January, while preparing a new course, Robert Seydel was struck and killed by an unexpected heart attack. He was a critically under-appreciated artist and one of the most beloved and admired professors at Hampshire College. At the time of his passing, Seydel was on the brink of a major artistic and career milestone. His Book of Ruth was being prepared for publication by Siglio Press. His publisher describes the book as: “an alchemical assemblage that composes (...) the life of his alter ego, Ruth Greisman— spinster, Sunday painter, and friend to Joseph Cornell and Marcel Duchamp. Through collages, drawings, and journal entries from Ruth’s imagined life, Seydel invokes her interior world in novelistic rhythms.” This convergence of his professional triumph with the tragedy of his death makes now a particularly appropriate time to think about Robert Seydel and his work. This feature contains a selection of excerpts from Book of Ruth (courtesy of Siglio Press) alongside a pair of texts remembering him and giving critical and biographical insights into his art and his person. These texts, from a former student and a colleague respectively, were originally prepared for Seydel's memorial at Hampshire College and have since been revised for publication in continent. For more information on Book of Ruth, please visit the book's page at the Siglio Press website. —Ben Segal draughty R. * Lauren van Haaften-Schick 2011 “The most apt way to order Smithson's library is with the conjunction 'and'; science and religion; modernism and mass culture; what is present and what is missing.” —Alexander Alberro, 248 Robert Seydel's classes on collage and collecting immersed his students in a curious world of cabinets, oddities, exhaustive archives and obscure histories, explored always with critical rigor and a sincere eye for wonder. His office was a compendium of the ancient, mythic, potential and unworldy, where seemingly unrelated references were endlessly pulled, piled and fused in an ecstatic dance of hyper-annotation. The small room and all its contents overflowed with notes tucked in every margin and corner. Books coated the walls like a switchboard, anxious and humming, waiting for infinite links to be activated. William Blake's books of Job and Urizen summoned Greek mythology and the animal as metaphor, leading to 19th century cryptozoology and the cave paintings at Lascaux, Gaston Bachelard's description of the bird in his garden and Robert Rauschenberg's Canyon . Tracking archetypes and following tangential threads, new revelations and ancient narratives were compiled and ordered to form a new text, a bibliography as assemblage, portrait and poem. Robert's library—one of his many collections—is a portrait, an “artifact, collage of time, a token and remnant” (Seydel, 2007) He is humming with it still. The imagination of this room—of Robert—breathes through the pages of Book of Ruth, as every decision and detail unfolds to a cosmos. Allegory, invention, personal and art histories are entangled and leveled, rendering lived, perceived and absorbed experiences indistinguishable. Anonymous scraps discovered on the street or studio floor, careful clippings and drawn figures are chosen and animated through serendipitous destruction and whimsical, delicate positioning. A precise vocabulary of characters and terms erupts and collapses as personas and passers-by wave and whisper, “Every figure reveals aspects of the total form, which is open and green” (Seydel, 2007). The initials R.S. repeat, a nod to Robert's true family tree and further complicating identification. Robt, Robert's sometimes alter-ego, appears in myriad forms as a trickster “half-wit,” mercurial and skittish, or soft and worn thin. Saul is a solemn tinkerer, parsing the world and sometimes blind. Ruth, the speaker of the book, records and translates all, her voice wavering between poetic verse and a cryptic half-speech as complex as it is sparse. The rhythm of frayed edges sets time - the weight of the world and the lightness of paper. Robert wrote of his process, “Material is essential; scuffings carry history, which wanders throughout” (Seydel, 2007). Collectors, assemblers, sway between careful movements of selection and placement as they pull from the found world, mediating calculated and unconscious association to form a lexicon of gestures, symbols and allusion, the “artifacts of a life... the refuse and rejecta of days” (Seydel, 2007). These assembled fragments shift and chatter, at home in their homelessness, actors performing in their own lives, populating an invented world of similar orphans. Such accumulated, severed parts carry the injury of their cutting and retain the evidence of their source, binding loss to creation in a symbiosis of trauma and repair. Mourning and remembrance are deeply embedded in the histories and acts of such practices. Grievance, acceptance, and the fragility of life are conveyed in the 18th century allegorical arrangements of fetal specimens by Frederik Ruysch. A certain melancholy reverence colors Joseph Cornell's intimately tactile assemblages rendering the universe tangible in miniature, or made in devotion to unrequited loves. Preserved in stasis, these ghosts and idols are kept in a purgatory where fact and fiction, past and present are irrelevant distinctions. Catalogued and contained, the subject of loss is transferred to an artifact. Every thread, scrap and letter may be glued, gathered and placed in a museum, a tomb, a box, a page, ripe and open for possession. Holding on to grief and reveling in disrepair, we opt to be haunted. Forever unbalanced and in flux, the sublime of collage is its resolve to irresolution. For Robert, “Art, as creation and as sign of primary Imagination, is not objects but a state, a kind of fluid” (Seydel, 2007) Reflecting on his work, life, and death, I am drawn to my library and the myriad titles acquired through his inspiration. There is Daniel Spoerri's An Anecdoted Topography of Chance , Susan Stewart's On Longing , various Borges, Barthes, Perec, and especially Life: A User's Manual , which concludes that the perfect puzzle will have no solution. I think of the drawers of miscellaneous swallowed objects at the Mutter Museum, Ray Johnson coding the every day in riddles, Wallace Berman twisting tongues, and Susan Hiller laying every detail to bear. Collectors and makers working in endless cycles of observation, ingestion and display. Every gesture informs and is defined by others, every space is shaped by that which surrounds and fills it, the knot has an inner logic, the gigantic is not so different from the miniature, there is a world in every detail, and “All art is collage” (Seydel, 2011) These thoughts have molded my life, my art, and all the minutia that keep the two so profoundly intertwined; There is no difference between life and what we do with our time. “I write my life. I make me up.” What a gift to share this secret way of knowing the world, and to leave this knowledge for us to do with what we please. “Art begins in admiration” (Seydel, 2011) Lauren van Haaften-Schick is a curator, writer and artist based in New York. Upcoming curatorial projects include "Cancelled" at the Center for Book Arts, and "The Spirit of the Signal" at Nicole Klagsbrun Gallery, New York. Recent activities include the workshops "Market, Alternative" and "Alternative Art Economies" at Trade School and Momenta Art, and the e-flux Time/Store, New York. She is the founding director of two arts spaces in Northampton, MA and Philadelphia, PA. She received a BA in Art History and Studio Art from Hampshire college in 2006. Sura Levine on Robert Seydel If early on in his time at Hampshire College I was officially his “mentor,” Robert Seydel quickly became one of my great teachers. Over the years we talked about everything, from art, music, collage, and poetry, to campus politics, this latter far too often. It was always a sublime pleasure, if all too rarely done, to enter his apartment to look at his work in progress, to peruse his bookshelves where, inevitably, there were always new treats to examine. And, while he was working on his Book of Ruth , I was given the opportunity over the course of many meals at the Korean and other restaurants, to talk with him about image and poem ordering. To see how he thought through each comma, each juxtaposition across the gutters of the Book, was to watch a brilliant curator at work. Each day, I walk past his wonderful collaged portrait of Ruth, purchased, after much haggling, as a birthday present, a couple of years ago. And each day, I think how lucky I am to have known Robert as he produced this magnum opus. One of my greatest pleasures in 24 years at the College was to teach “The Collector” with Robert. One of my greatest regrets is that the magic we created together in the classroom will not, and cannot, be duplicated. Its various incarnations, its utter intelligence and magic, were all so deeply Robert’s. His was a mind that put poetry, philosophy, history of science, and history together with art, and art together with music. His intellect and eye were unparalleled. He introduced us to so many artists. He shared his fascination with the cabinets of curiosity of Aldrovandi, of Seba, and Peter the Great’s collection of fetal anomalies, as well as the Museum of Jurassic Technology in Los Angeles. Robert knew them all and so many more. He was a walking encyclopedia, his home a great archive. Arcane knowledge, perhaps, but oh so important for another of Robert’s heroes, the mid-20th century Belgian artist Marcel Broodthaers, whose name he invariably mispronounced as “Broadthayers.” In speaking his name, Robert would always look in my direction in a panic, and then he go on and maul it. I absolutely loved his various mispronunciations of French names and terms! “The Collector” was always filled with talented young artists, art historians, philosophers and writers who all came to understand the wondrous obsessions of the figure of the collector. Students in this course created dazzling projects each term. He always moved while looking and speaking. He read deeply, and commented on everyone’s work with wonderful generosity. Robert always found something to praise even in the least developed of projects. Robert inspired and mentored all of his students into making work that far exceeded their expectations—and ours. For those of you who were lucky enough to have been touched by or to have had an evaluation written by Robert, savor it, keep it, reread it, and share it. He loved working with you all; it is somehow fitting that he died while prepping yet another new course. Robert, it’s almost impossible to speak of you in the past tense, even though you left us a month ago. No doubt, if you knew about our gatherings and celebrations of you, you would be embarrassed that we are making a fuss over you; you always placed the focus on others rather than on yourself. This trait is exactly why so many people miss you now. We’re here to love you publicly as we all did privately for the eleven years you were among us. Robert, my very dear friend, you were an extraordinary artist—you were my brother of choice. My heart broke when yours did. I miss you profoundly. —Sura Levine, February 26, 2011 Sura Levine is a professor of art history at Hampshire College. Her field of specialty is 19th century Belgian and French art, particularly realism and impressionism. Having worked in museums for a number of years both prior to coming to the College, and, as guest curator and co-author of exhibition catalogues, she became particularly interested in the history of museum and trends in collecting. It was because of their shared interests that she and Robert Seydel developed their course, The Collector, which they co-taught for many years. (shrink)

Supraspan verbal list-learning tests, such as the Rey Auditory Verbal Learning Test (RAVLT), are classic neuropsychological tests for assessing verbal memory. In this study, we investigated the impact of the meaning of the words to be learned on 3 memory stages (short-term recall, learning, and delayed recall) in a cohort of 447 healthy adults. First, we compared scores obtained from the RAVLT (word condition) to those of an alternative version of this test using phonologically similar but meaningless (...) items (pseudoword condition) and observed how each score varied as a function of age and sex. Then, we collected the participants’ self-reported strategies to retain the word and pseudoword lists and examined if these strategies mediated the age and sex effects on memory scores. The word condition resulted in higher memory scores than pseudoword condition at each memory stage and even canceled out, for the learning stage, the detrimental effect of age that was observed for the short-term and delayed recall. When taking sex into account, the word advantage was observed only in women for short-term recall. The self-reported strategies, which were similar for words and pseudowords, were based on the position of the item on the list (word: 53 %, pseudoword: 37%) or the meaning of the item (word: 64%, pseudoword: 58%) and were used alone or in combination. The best memory performance was associated with the meaning strategy in the word condition and with the combination of the meaning and position strategies in the pseudoword condition. Finally, we found that the word advantage observed in women for short-term recall was mediated by the use of the meaning strategy. The RAVLT scores were thus highly dependent on word meaning, notably because it allowed efficient semantic knowledge-based strategies. Within the framework of Tulving’s declarative memory model, these results are at odds with the depiction of the RAVLT as a verbal episodic memory test as it is increasingly referred to in the literature. (shrink)

A defining characteristic of Alzheimer’s disease is difficulty in retrieving semantic memories, or memories encoding facts and knowledge. While it has been suggested that this impairment is caused by a degradation of the semantic store, the precise ways in which the semantic store is degraded are not well understood. Using a longitudinal corpus of semantic fluency data, we derive semantic network representations of patients with Alzheimer’s disease and of healthy controls. We contrast our network-based approach with analyzing fluency data (...) with the standard method of counting the total number of items and perseverations in fluency data. We find that the networks of Alzheimer’s patients are more connected and that those connections are more randomly distributed than the connections in networks of healthy individuals. These results suggest that the semantic memory impairment of Alzheimer’s patients can be modeled through the inclusion of spurious associations between unrelated concepts in the semantic store. We also find that information from our network analysis of fluency data improves prediction of patient diagnosis compared to traditional measures of the semantic fluency task. (shrink)

A great deal of research has demonstrated that learning is influenced by the learner’s prior background knowledge (e.g. Murphy, 2002; Keil, 1990), but little is known about the processes by which prior knowledge is deployed. We explore the role of explanation in deploying prior knowledge by examining the joint effects of eliciting explanations and providing prior knowledge in a task where each should aid learning. Three hypotheses are considered: that explanation (...) and prior knowledge have independent and additive effects on learning, that their joint effects on learning are subadditive, and that their effects are superadditive. A category learning experiment finds evidence for a superadditive effect: explaining drives the discovery of regularities, while prior knowledge constrains which regularities learners discover. This is consistent with an account of explanation’s effects on learning proposed in Williams & Lombrozo (in press). (shrink)

A special report of The Hastings Center and the Association of American Medical Colleges addressed the ethical oversight of learning health systems, which seek to combine high‐quality patient care with routine data collection aimed at improving patient outcomes. The report contained two position papers, authored by a number of distinguished bioethicists, and several commentaries. The position papers urged two changes. First, they urged a rethinking of our approach to the regulation of human subjects research, so as to (...) make it easier in the future for learning health systems to function well. Second, they argued that the rethinking required dispensing with a strict distinction between research and therapy, which has been a major tenet of bioethics since the Belmont Report, which explicated basic ethical principles governing human subjects research. We fully support the objectives of the authors, and we agree that the learning health system is an important advance that serves patients well. Unnecessary regulatory burden ought not impede this progress. We disagree, however, that the best way to bring about these needed changes in the regulatory environment is to reject the basic distinction between research and treatment. Unfortunately, we find the arguments in favor of that strategy to be, in places, reminiscent of what we take to be basic conceptual errors that hampered the ethical understanding of human subjects research prior to adoption of the Belmont Report. To see why one need not reject the research‐treatment distinction in order to promote learning health systems, we first investigate in some detail the arguments offered for eliminating the distinction. We next turn to an issue not addressed by those authors, namely, the relationship between the physician or investigator and the patient or subject, to illustrate why the distinction is important and what is lost if it is jettisoned. (shrink)