10,371 research outputs found
THE ROLE OF FRONTO-PARIETAL AREAS IN THE MOTOR REPRESENTATION OF THE PERIPERSONAL SPACE (PPS)
No full textIntroduction: In order to interact with the external world, our brain integrates multisensory cues about environmental stimuli with information about the body in a coherent representation of the Peripersonal Space (PPS). A network of fronto-parietal regions, involving the ventral premotor cortex (vPMc) and the posterior parietal cortex (PPc), might support this function, since neurons in these areas integrate somatosensory with visual and acoustic stimuli near the body [1,2]. Previous TMS studies have highlighted the motor counterpart of PPS by showing that stimuli presented near or far from the hand are capable of modulating the excitability of the hand representation in the motor cortex (M1) [3,4].
Here we test whether M1 modulation due to PPS representation relies on the activity of two key nodes of the PPS fronto-parietal network, namely vPMc and PPc. To this aim we used a ‘perturb-and-measure’ paradigm [5]: transcranial direct current stimulation (tDCS) was applied to transiently suppress activity in vPMc or PPc; then single-pulse TMS was used to measure the excitability of the hand motor representation, when an acoustic stimulus was presented either near the hand or in the far space.
Methods: 15 minutes of cathodal, inhibitory, tDCS were applied to target areas (vPMc and PPc) or to V1, serving as a control site. Single-pulse TMS was applied to the hand area of M1 and motor-evoked potentials (MEPs) from FDI muscle were recorded after presenting a sound either at ≈5 cm (NEAR sounds) or at ≈100 cm (FAR sounds) from the hand. TMS pulses were delivered at 120% of resting motor threshold (rMT), at 3 different intervals (50, 175, and 300 ms) after sound presentation. In Experiment 1 (16 subjects), we compared MEPs after Real-tDCS over vPMc (test) or after Sham-tDCS over the same site (sham control). In Experiment 2 (12 subjects), we compared the effect of Real-tDCS over PPc (test) or over V1 (active control).
Results: After the sham stimulation, we found a space-specific modulation of the hand motor representation: MEP amplitudes recorded at 300 ms after the onset of near sounds were lower than those recorded after far sounds, confirming that stimuli near the hand may suppress hand M1 excitability [3,4]. This motor modulation disappeared after Real-tDCS over vPMc. In contrast, Real-tDCS over PPc or V1 did not affect the space-specific modulation of M1: MEPs recorded at 300ms from sound onset were again lower when a near, compared to a far sound, was presented.
Conclusions: PPS representation implies both (multi)sensory (processing external stimuli potentially approaching the body) and motor functions (preparing appropriate motor responses) [1-4]. By using a tDCS-TMS perturb-and-measure paradigm [5] we showed that inhibitory motor response to sounds presented near the body was disrupted by suppression of vPMc, but not of PPc or V1. Our findings suggest a crucial role of vPMc in the motor representation of the PPS. Thus, the two nodes of the fronto-parietal network representing the PPS have partially dissociable functions, being vPMc, rather than PPc, mainly involved in transforming sensory representations of space in motor responses.
References:
1. Graziano MS, Cooke DF (2006) Parieto-frontal interactions, personal space, and defensive behavior. Neuropsychologia 44, 845-859.
2. Bremmer F, Schlack A, Shah NJ, Zafiris O, Kubischik M, Hoffmann K, et al. (2001) Polymodal Motion Processing in Posterior Parietal and Premotor Cortex: A Human fMRI Study Strongly Implies Equivalencies between Humans and Monkeys. Neuron 29, 287-296
3. Serino A, Annella L, Avenanti A (2009) Motor Properties of Peripersonal Space in Humans. PLoS ONE 4, e6582.
4. Makin TR, Holmes NP, Brozzoli C, Rossetti Y, Farnè A (2009) Coding of visual space during motor preparation: Approaching objects rapidly modulate corticospinal excitability in hand-centered coordinates. Journal of Neuroscience 29, 11841-51.
5. Avenanti A, Bolognini N, Maravita A, Aglioti SM (2007) Somatic and motor components of action simulation. Current Biology 17, 2129-35
Correspondence: Laura Kephart and Arthur Stupka
No full textThis 1936 correspondence, between Laura Kephart (Mrs. Horace Kephart) and Arthur Stupka, concerns a possible Kephart Memorial. Horace Kephart (1862-1931) was a noted naturalist, woodsman, journalist, and author and promoter of the Great Smoky Mountains National Park. Arthur Stupka (1905-1999) was the first park naturalist to work at the Great Smoky Mountains National Park
Mindscapes: Laura Riding's poetry and poetics /
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão.Esta tese propõe uma leitura revisionista da poesia contemporânea através do exame do caso de um dos mais esquecidos escritores norte-americanos do século XX: Laura (Riding) Jackson (1901-1991). O objetivo é demonstrar que Riding não apenas possuía uma poética definida e singular, mas que ela permanece uma das instâncias mais extremas e paradoxais do modernismo anglo-americano, a ponto de Riding abandonar a escrita da poesia em 1938. Recorrendo a conceitos de "formação do cânone" bem como às noções de "discurso" e "função do autor", em Foucault, investigo a construção do cânone da poesia moderna anglo-americana, recuperando o contexto e as circunstâncias da ocultação de Riding. Enquanto cubro os "discursos" poéticos em circulação na primeira metade do século XX-o "imagismo" de Pound, a "dissociação da sensibilidade", "impersonalidade" e "tradição" de Eliot, a "unidade orgância" e "ambigüidade" da Nova Crítica-ofereço um panorama crítico de modernismos alternativos sendo articulados à época. Minha intenção é demonstrar que os poemas de Riding são expressões vigorosas de um escritor para quem "a mente pensando se torna a força ativa do poema", para usar a apta formulação de Charles Bernstein. Entre minhas descobertas sobre as várias e complexas razões que levaram à não-canonização de Riding estão a hegemonia da Nova Crítica, o exílio voluntário de Riding da cena literária (onde são feitas ou desfeitas as reputações), sua recusa em ser antologiada, bem como em ser explicada em termos críticos que não os dela. Todos esses fatores, mais a "dificuldade" de sua poesia, contribuíram para fazer de Riding "a maior poeta esquecida da poesia norte-americana", como escreveu Kenneth Rexroth. Ajudado pelos insights de dois importantes críticos de poesia norte-americana, Charles Bernstein e Marjorie Perloff, defendo que a "poesia da mente" de Riding-onde o que está em jogo é que o que pensamos ser a nossa realidade-representa uma mudança radical no paradigma da poética modernista: de uma poesia centrada na imagem para uma poesia centrada na linguagem. Focalizando a experiência consciente e o tempo duracional do pensamento presente em seus poemas, concluo que as "pensagens" de Riding têm o objetivo preciso de constatar um fato universal: enquanto seres humanos e pensantes, estamos numa condição permanente chamada linguagem
Motor properties of peripersonal space in humans.
No full textBACKGROUND:A stimulus approaching the body requires fast processing and appropriate motor reactions. In monkeys, fronto-parietal networks are involved both in integrating multisensory information within a limited space surrounding the body (i.e. peripersonal space, PPS) and in action planning and execution, suggesting an overlap between sensory representations of space and motor representations of action. In the present study we investigate whether these overlapping representations also exist in the human brain. METHODOLOGY/PRINCIPAL FINDINGS:We recorded from hand muscles motor-evoked potentials (MEPs) induced by single-pulse of transcranial magnetic stimulation (TMS) after presenting an auditory stimulus either near the hand or in far space. MEPs recorded 50 ms after the near-sound onset were enhanced compared to MEPs evoked after far sounds. This near-far modulation faded at longer inter-stimulus intervals, and reversed completely for MEPs recorded 300 ms after the sound onset. At that time point, higher motor excitability was associated with far sounds. Such auditory modulation of hand motor representation was specific to a hand-centred, and not a body-centred reference frame. CONCLUSIONS/SIGNIFICANCE:This pattern of corticospinal modulation highlights the relation between space and time in the pps representation: an early facilitation for near stimuli may reflect immediate motor preparation, whereas, at later time intervals, motor preparation relates to distant stimuli potentially approaching the body
Letter, Julia Gardiner Tyler to Mrs. Laura Holloway, author of First Ladies, dated September 20, 1869
No full textALS of Julia Gardiner Tyler to Mrs. Laura Holloway, author of First Ladies, dated September 20, 1869, about interviewing other first ladies. ALS.Found in:Mss. 65 T97 Additions, Series 1: Mss. Acc. 1993.19 Addition, 186
Heritage tourism: a case study of the Laura Ingalls Wilder Heritage Site at Pepin, Wisconsin
No full textPlan BMany things must be taken into consideration when developing a heritage tourism site. It can be a wonderful opportunity for the community involved to benefit economically and historically. Heritage tourism can keep alive the heritage and traditions of the communities past. When it is discovered that a heritage site exists, the first step is to consult with the community. A site will not succeed without the acceptance and assistance from the community involved. Once the interest is known, the development process can proceed. After determining that there is a heritage tourism site possibility in their area, a commumity must do research to determine the feasibility of the site, what will make it a success, and how to obtain that success. This study will examine a community with a heritage tourism site that has been successful in developing and maintaining it's site. By conducting this study, other communities seeking information for developing their site will have an example and tool to work with. The site chosen for this study is the Laura Ingalls Wilder site in Pepin, Wisconsin. The town is rich with it's heritage associated with Laura Ingalls Wilder. The development and success for this town will be documented through this study. Laura Ingails Wilder is a perfect choice for examining heritage tourism. The author of many American Pioneer books, she has become famous all over the world. In turn all places that she or her family members lived are or are becoming heritage tourism sites. There are older ones that have been in progress for some years, such as the one in Pepin, and there are ones that are being discovered through the popularity of new books written about Laura's family. These communities would benefi greatly from the information this study will produce. Without the bene-fit of this knowledge communities who are unaccustomed to tourism or the way the other Laura Ingalls Wilder sites operate, may make terrible errors in development, tarnishing the site. This may also reflect badly on the other Laura Ingalls Wilder sites. It is important for new Wilder sites to examine all information and know exactly what they are doing when developing the site. If all the Laura Ingalls Wilder sites can benefit from each other's knowledge and experience it will greatly increase the market for all sites. The more detailed and expansive the sites are about their knowledge and sites to see, the more people are going to want to travel to as many sites as possible, learning all they can about the life of Laura Ingalls Wilder and her family. These sites not only attract Laura Ingalls Wilder fans but all people that are interested in the American Pioneer period of the United States history. This study will provide the knowledge for communities who are developing heritage tourism sites, especially those focusing on Laura Ingalls Wilder. This is a very important study for tourism and especially heritage tourism. When a heritage site is discovered communities run into the barrier of not having the experience and knowledge to develop the site properly. This study will analyze tourism in Pepin, Wisconsin to determine it's successfulness due to the fact that it is a Laura Ingalls Wilder heritage tourism site, and Wfit was developed in a way to provide tourists with a view of Laura Ingalls Wilder's past and the past of many Pioneer Americans. By studying this subject it will allow for many people to benefit. Tourist who are seeking the pleasure of the knowledge of the past, and communities who want to preserve their past and profit from tourism
Core Journal Lists: Classic Tool, New Relevance
No full textReviews the historical context of core journal lists, current uses in collection assessment, and existing methodologies for creating lists. Outlines two next generation core list projects developing new methodologies and integrating novel information/data sources to improve precision: a national-level core psychology list and the other a local institutional core list for the interdisciplinary field of urban studies and planning. The paper is based on the authors’ panel presentation at the 2009 ACRL National Conference (Seattle, Washington) titled “Core Journal Lists Re-viewed and Re-imagined.”This is an electronic version of an article published in Robin A. Paynter, Rose M. Jackson & Laura Bowering Mullen (2010): Core Journal Lists: Classic Tool, New Relevance, Behavioral & Social Sciences Librarian, 29:1, 15-31. Behavioral & Social Sciences Librarian is available online at: http://www.tandfonline.com, http://dx.doi.org/10.1080/01639260903571096Peer reviewe
Combining TMS and tDCS to investigate peripersonal space representations in the Human motor system
No full textInteracting with the external world requires the integration of multisensory cues about environmental stimuli with information about the body in a coherent representation of the Peripersonal Space (PPS). A network of fronto-parietal regions, involving the ventral premotor cortex (vPMc) and the posterior parietal cortex (PPc), might support this function, since neurons in these areas integrate somatosensory with visual and acoustic stimuli near the body. Although recent TMS studies have shown that stimuli presented near or far from the hand are capable of modulating the excitability of the hand motor representation, information on the causal influence of PPS network in this motor modulation is lacking.
Here we test whether motor modulation contingent upon the processing of stimuli within PPS relies on the activity of two key nodes of the putative human PPS network, namely the vPMc and the PPc. To this aim we used a ‘perturb-and-measure’ paradigm combining tDCS and TMS techniques. Cathodal tDCS (15 min, 1mA) was applied to transiently suppress cortical excitability in two target areas (vPMc and PPc) or in V1, serving as control site. Single-pulse TMS (120% of rMT) was used to measure hand corticospinal excitability and motor-evoked potentials (MEPs) from the right FDI muscle were recorded and compared when an acoustic stimulus was presented either near the hand or in the far space. TMS pulses were delivered at 3 different intervals (50, 175, and 300 ms) after sound presentation.
In Experiment 1 (16 subjects), MEPs were recorded after Real-tDCS over vPMc (test) or after Sham-tDCS over the same site (sham control). After the sham stimulation, we found a space- and temporal-specific modulation of the hand motor representation: MEP amplitudes recorded at 300 ms after the onset of near sounds were lower than those recorded after far sounds, confirming that stimuli near the hand may reduce hand corticospinal excitability. This motor modulation disappeared after Real-tDCS over vPMc.
In Experiment 2 (12 subjects), we compared the effect of Real-tDCS over PPc (test) or over V1 (active control). We found that stimulation of these two regions did not disrupt motor modulation due to stimuli within PPS: MEPs recorded at 300ms from sound onset were again lower when a near, compared to a far sound, was presented.
PPS representation implies both (multi)sensory (processing external stimuli potentially approaching the body) and motor functions (preparing appropriate motor responses). By combining tDCS and TMS we showed that inhibitory motor response to sounds presented near the body was disrupted by suppression of vPMc, but not of PPc or V1. Our findings suggest a crucial role of vPMc in the motor representation of the PPS. Thus, the two nodes of the putative PPS network have partially dissociable functions, being vPMc, rather than PPc, critically involved in transforming sensory representations of space into motor responses
IATUL 32nd Conference 2011, “Libraries for an Open Environment: Strategies, Technologies and Partnerships,” Warsaw University of Technology, Warsaw, Poland, 29 May-2 June 2011
No full textThis report provides details recorded from the author's attendance at the IATUL 2011 conference in Warsaw, Poland, May 29-June 2, 2011.This is a post-print version of an article that published in Library Hi Tech News. The published version is available at http://www.emeraldinsight.com/journals.htm?issn=0741-9058&volume=28&issue=8&articleid=1958452&show=abstrac
IFLA satellite pre-conference: open access to science information: trends, models and strategies for libraries
No full textThe purpose of this paper is to disseminate information about the IFLA pre-conference in Chania, Crete, Greece on the subject of open access in libraries.This is a post-print version of an article published in Library Hi Tech News. The published version of the article is available at http://www.emeraldinsight.com/journals.htm?issn=0741-9058&volume=27&issue=6/7&articleid=1891644&show=abstrac
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