Viewpoint-Specific Scene Representations in Human Parahippocampal Cortex

AbstractThe “parahippocampal place area” (PPA) responds more strongly in functional magnetic resonance imaging (fMRI) to scenes than to faces, objects, or other visual stimuli. We used an event-related fMRI adaptation paradigm to test whether the PPA represents scenes in a viewpoint-specific or viewpoint-invariant manner. The PPA responded just as strongly to viewpoint changes that preserved intrinsic scene geometry as it did to complete scene changes, but less strongly to object changes within the scene. In contrast, lateral occipital cortex responded more strongly to object changes than to spatial changes. These results demonstrate that scene processing in the PPA is viewpoint specific and suggest that the PPA represents the relationship between the observer and the surfaces that define local space

Determining the Impact of Autobiographical Experience on "Meaning": New Insights from Investigating Sports-related Vocabulary and Knowledge in Two Cases with Semantic Dementia

Snowden, Griffiths, and Neary (1994, 1995) have proposed thatautobiographical experience helps to maintain the integrity of semantic memory in patients with semantic dementia. We investigated this hypothesis by testing knowledge related to golf and bowls in two case studies. If Snowden and colleagues' hypothesis is correct, our two patients should have better semantic knowledge for the sport that they regularly experience, compared with knowledge of other sports. In keeping with Snowden et al's hypothesis, we found that autobiographical experience influenced the ability of the patients to match up a surname with a first name: The names of personally and currently relevant golf bowls partners were more likely to be matched correctly than such personally relevant names from the past, or the names of famous sports celebrities. Unlike Snowden et al., however, we found that knowledge of people, in all categories, was severely impoverished and that any semantic information was produced as part of an autobiographical memory. Likewise, detailed study of each patient's understanding of their favourite sportrevealed no significanteffectof autobiographical experience on true semantic knowledge. We propose that the ability of semantic dementia patients to encode, albeit temporarily, recent autobiographical memories via a spared hippocampal complex supports the production of highly autobiographically constrained semantic-like facts and, to a lesser extent, frequently encountered names. There is, however, no direct effect of autobiographical experience on previously established semantic memory, i.e. knowledge of golf, bowls, and people, presumably stored within the temporal neocortex. These results are discussed with respect to current anatomically based computational models of long-term memory

A questionable semantics: The interaction between semantic knowledge and autobiographical experience in semantic dementia

In our earlier article, we proposed that recent episodic experiences in patients with semantic dementia support the production of nongeneralisable, autobiographically constrained, “semantic-like” facts (Graham, Lambon Ralph, & Hodges, 1997). We argued that this type of “semantic-like” knowledge was distinguishable from true semantic information because our two patients with semantic dementia showed no facilitatory effect of recent autobiographical experiences on their knowledge of golf and bowls; information which was presumably learnt prior to the onset of their disease. In this paper, we discuss the implications of these results for current views relating to the nature and organisation of long-term memory

Promoting environmental management in very small businesses through “Green Angels” in a local collaborative partnership: a case study from Brighton, England

This paper describes the results of the East Brighton Employment and Environment Centre (EBEEC), a 15 month URBAN project, promoting environmental management to very small businesses in east Brighton, England. Some 31 volunteers, termed `Green Angels`, were trained in waste minimisation at the University of Brighton, and provided practical support to local firms through site reviews and research. The EBEEC project provided information and support to some 600 SMEs in east Brighton, via newsletters, email, telephone helpline, seminars and other projects. The Project was managed by a collaborative partnership formed from regional as well as local organisations. The involvement of a University to train potential `Green Angels`, so as to support SMEs in an area designated for economic regeneration, was an innovative and successful method of providing environmental management support to small firms. To stimulate the uptake of environmental management, case study material based on Best Practice was produced and disseminated to local companies via an Internet Site. A CD-Rom containing the Green Angel training package has been produced to help other projects like this. The outcomes from this Project will inform the regional and potentially the national approach to providing environmental business support and advice via local collaborative partnerships containing Universities

Entropy Production of Brownian Macromolecules with Inertia

We investigate the nonequilibrium steady-state thermodynamics of single Brownian macromolecules with inertia under feedback control in isothermal ambient fluid. With the control being represented by a velocity-dependent external force, we find such open systems can have a negative entropy production rate and we develop a mesoscopic theory consistent with the second law. We propose an equilibrium condition and define a class of external forces, which includes a transverse Lorentz force, leading to equilibrium.Comment: 10 pages, 1 figur

Quantum interference of ultrastable twin optical beams

We report the first measurement of the quantum phase-difference noise of an ultrastable nondegenerate optical parametric oscillator that emits twin beams classically phase-locked at exact frequency degeneracy. The measurement illustrates the property of a lossless balanced beam-splitter to convert number-difference squeezing into phase-difference squeezing and, thus, provides indirect evidence for Heisenberg-limited interferometry using twin beams. This experiment is a generalization of the Hong-Ou-Mandel interference effect for continuous variables and constitutes a milestone towards continuous-variable entanglement of bright, ultrastable nondegenerate beams.Comment: 4 pages, 4 figs, accepted by Phys. Rev. Let

Naming in semantic dementia - What matters?

One of the major symptoms of semantic dementia (or progressive fluent aphasia) is profound word-finding difficulties. We present here a cross-sectional study of the factors affecting picture naming in semantic dementia based on data obtained from eight patients, together with a longitudinal analysis of naming in another patient. Various properties and attributes of the objects were entered into a series of regression analyses in order to predict which items the patients could or could not name. The analyses showed that object familiarity, word frequency and age-of-acquisition predicted naming success for the group and, in most cases, for each individual patient, irrespective of lesion site or overall naming success. We propose that the pattern of naming in semantic dementia is best described in terms of reduced semantic activation within a cascading\interactive speech production system. We suggest that object familiarity, and possibly word frequency, reflect the inherent robustness of individual semantic representations to the decay process in terms of both quantity and quality of experience. Age-of-acquisition and word frequency (at a phonological–lexical level) predicts naming success, because frequent, early-acquired words are relatively easy to activate even with reduced semantic "input"

Distinct contributions of the fornix and inferior longitudinal fasciculus to episodic and semantic autobiographical memory

Autobiographical memory (AM) is multifaceted, incorporating the vivid retrieval of contextual detail (episodic AM), together with semantic knowledge that infuses meaning and coherence into past events (semantic AM). While neuropsychological evidence highlights a role for the hippocampus and anterior temporal lobe (ATL) in episodic and semantic AM, respectively, it is unclear whether these constitute dissociable large-scale AM networks. We used high angular resolution diffusion-weighted imaging and constrained spherical deconvolution-based tractography to assess white matter microstructure in 27 healthy young adult participants who were asked to recall past experiences using word cues. Inter-individual variation in the microstructure of the fornix (the main hippocampal input/output pathway) related to the amount of episodic, but not semantic, detail in AMs e independent of memory age. Conversely, microstructure of the inferior longitudinal fasciculus, linking occipitotemporal regions with ATL, correlated with semantic, but not episodic, AMs. Further, these significant correlations remained when controlling for hippocampal and ATL grey matter volume, respectively. This striking correlational double dissociation supports the view that distinct, large-scale distributed brain circuits underpin context and concepts in AM

The nuclear X-ray emission of nearby early-type galaxies

Nuclear hard X-ray luminosities (Lx,nuc) for a sample of 112 early type galaxies within a distance of 67 Mpc are used to investigate their relationship with the central galactic black hole mass Mbh, the inner galactic structure (using the parameters describing its cuspiness), the age of the stellar population in the central galactic region, the hot gas content and the core radio luminosity. Lx,nuc ranges from 10^{38} to 10^{42} erg/s, and the Eddington ratio Lx,nuc/Ledd from 10^{-9} to 10^{-4}. Lx,nuc increases on average with the galactic luminosity Lb and Mbh, with a wide variation by up to 4 orders of magnitude at any fixed Lb>6x10^9 Lb,sun or Mbh>10^7 Msun. This large range should reflect a large variation of the mass accretion rate \dotMbh. On the circumnuclear scale, \dotMbh at fixed Lb (or Mbh) could vary due to differences in the fuel production rate from the stellar mass return linked to the inner galactic structure; however, \dotMbh should vary with cuspiness by a factor exceeding a few only in hot gas poor galaxies and for large differences in the core radius. Lx,nuc does not depend on age, but less luminous nuclei are found among galaxies with a younger stellar component. Lx,nuc is detected both in gas poor and gas rich galaxies, on average increases with the total galactic hot gas cooling rate L_{X,ISM}, but again with a large variation. The lack of a tight relationship between Lx,nuc and the circumnuclear and total gas content can be explained if the gas is heated by black hole feedback, and/or the mass effectively accreted can be largely reduced with respect to that entering the circumnuclear region. Differently from Lx,nuc, the 5 GHz VLA luminosity shows a trend with the inner galactic structure similar to that of the total soft X-ray emission; therefore they could both be produced by the hot gas.Comment: To appear in the ApJ, 21 page

A survey of bariatric surgical and reproductive health professionals' knowledge and provision of contraception to reproductive-aged bariatric surgical patients

BACKGROUND: Over 80 % of bariatric surgical patients are women with obesity in their reproductive years. Obesity adversely affects fertility; the rapid weight loss following bariatric surgery can increase fecundity. Current guidelines recommend avoiding pregnancy for up to 24 months following surgery, but little is known about current contraceptive care of women who undergo bariatric surgery. Two surveys were undertaken with bariatric surgical and contraceptive practitioners in England to establish current contraceptive practices in both groups. METHODS: Two anonymous on-line surveys were sent to all 382 members of the British Obesity and Metabolic Surgery Society (BOMSS) and an estimated 300 contraceptive practitioners in the North East of England. RESULTS: The BOMSS survey elicited a response rate of 17 % (n = 65), mainly from bariatric surgeons (n = 24 (36 %)). Most respondents (97 %) acknowledged the need to educate patients, but contraceptive information was only provided by 7 % (n = 4) of respondents in bariatric surgical clinics. Less than half of respondents were confident discussing contraception, and the majority requested further training, guidance and communication with contraceptive practitioners. The majority of respondents to the contraceptive practitioner survey were general practitioners (28 %, n = 20). Three quarters of respondents reported little knowledge of bariatric surgery, and many reported not seeing women with obesity requiring contraception before (66 %, n = 45) or after surgery (71 %, n = 49). CONCLUSIONS: There is a need to increase knowledge levels of contraception within bariatric surgical teams and to understand why, despite increasing levels of bariatric surgery, women do not seem to be appearing for advice in contraceptive settings