Attention and perceptual learning

Perceptual learning as a phenomenon. We are all of us experts. Each one of us is able to effortlessly distinguish between a large number of people that we encounter in our everyday lives. When considered as stimuli in the abstract this is a difficult discrimination task as the stimuli are all rather similar to one another, yet we can identify an individual in a moment with an accuracy that would put a supercomputer to shame. We will argue that this particular expertise comes about because we are very experienced with the class of stimuli in question (in this case faces), and that it is simply a more commonplace example of a type of expertise that we can study in twitchers (experts in the identification of birds), field botanists (experts in plant identification in a particular habitat) and dog show judges (experts in fine discriminations betweens dogs drawn from the same class such as gundogs; as reported in Perceptual learning, in its broadest sense, can be understood to be any enhancement of learning to a stimulus as a consequence of experience with that stimulus. Thus the proposal would be that perceptual learning is a consequence of the allocation of attention based on past experience with a particular stimulus type. This assertion is a natural (and plausible) response to the data, but is it the correct line to take? The question addressed in this chapter is whether perceptual learning phenomena can be explained by appealing to mechanisms that control attention (we will conclude that in some cases they can) or whether there is a need to appeal to other mechanisms as well (we hope to show that there is!). Starting with some examples of what might be considered perceptual learning phenomena taken from our early work, we go on to discuss them in the context of current research on perceptual learning, with an emphasis on analysing the possible role that attention might play in producing these effects. We will focus on perceptual learning in humans, but will allow ourselves to appeal to evidence from infra-human studies where appropriate. Enhanced acquisition of a discrimination after stimulus exposure. The general idea of the experiments reported here was to have participants learn discriminations in much the same circumstances as an animal (such as the rat) might. In the test or discrimination phase, a pair of stimuli would be presented side by side on a VDU with the arbitrarily designate

HST and UKIRT imaging observations of z~1 6C radio galaxies - II. Galaxy morphologies and the alignment effect

(abridged) Powerful radio galaxies often display enhanced optical/UV emission regions, elongated and aligned with the radio jet axis. The aim of this series of papers is to separately investigate the effects of radio power and redshift on the alignment effect, together with other radio galaxy properties. In this second paper, we present a deeper analysis of the morphological properties of these systems, including both the host galaxies and their surrounding aligned emission. The host galaxies of our 6C subsample are well described as de Vaucouleurs ellipticals, with typical scale sizes of ~10kpc. This is comparable to the host galaxies of low-z radio sources of similar powers, and also the more powerful 3CR sources at the same redshift. The contribution of nuclear point source emission is also comparable, regardless of radio power. The 6C alignment effect is remarkably similar to that seen around more powerful 3CR sources at the same redshift in terms of extent and degree of alignment with the radio source axis, although it is generally less luminous. The bright, knotty features observed in the case of the z~1 3CR sources are far less frequent in our 6C subsample; neither do we observe such strong evidence for evolution in the strength of the alignment effect with radio source size/age. However, we do find a very strong link between the most extreme alignment effects and emission line region properties indicative of shocks, regardless of source size/age or power. In general, the 6C alignment effect is still considerably stronger than that seen around lower redshift galaxies of similar radio powers. (abridged)Comment: 23 pages, 15 figures, accepted for publication in MNRAS. See http://www.mrao.cam.ac.uk/~kji/MorphPaper/ for version of paper with full resolution images of Figs 1-1

Decoding information in the human hippocampus: a user's guide

Multi-voxel pattern analysis (MVPA), or 'decoding', of fMRI activity has gained popularity in the neuroimaging community in recent years. MVPA differs from standard fMRI analyses by focusing on whether information relating to specific stimuli is encoded in patterns of activity across multiple voxels. If a stimulus can be predicted, or decoded, solely from the pattern of fMRI activity, it must mean there is information about that stimulus represented in the brain region where the pattern across voxels was identified. This ability to examine the representation of information relating to specific stimuli (e.g., memories) in particular brain areas makes MVPA an especially suitable method for investigating memory representations in brain structures such as the hippocampus. This approach could open up new opportunities to examine hippocampal representations in terms of their content, and how they might change over time, with aging, and pathology. Here we consider published MVPA studies that specifically focused on the hippocampus, and use them to illustrate the kinds of novel questions that can be addressed using MVPA. We then discuss some of the conceptual and methodological challenges that can arise when implementing MVPA in this context. Overall, we hope to highlight the potential utility of MVPA, when appropriately deployed, and provide some initial guidance to those considering MVPA as a means to investigate the hippocampus

Variability of Optical \ion{Fe}{ii} Complex in Narrow-Line Seyfert 1 Galaxy NGC 4051

The variability of optical FeII blends in NGC 4051 is examined from spectra extracted from the AGN Watch program.In our analysis, the FeII complex are subtracted and measured with the following results. Firstly, the FeII variations were detected in NGC 4051 during a 3-year period. The identified FeII variations followed the variations in continuum closely. Secondly, the EW of FeII is reported to increase with the rising continuum flux, which is consistent with previous claims that there is no convincing Baldwin Effect in optical FeII. Thirdly, by comparing the variations of H$\beta$ and FeII, we find that RFe scales with continuum flux as $\rm{R_{Fe}\propto (5.0\pm0.8) \log(L/M)}$, which is significantly different from the theoretical expectations. Finally, in six selected Seyferts, four out of five Narrow-Line Seyfert 1 galaxies present positive correlation between RFe and the continuum flux. The negative correlations are identified in the remaindng two objects that have relatively broad profiles of H$\beta$ ($\rm{FWHM>1500 km\ s^{-1}}$).We argue that the difference of electron density of broad line clouds and/or variability behavior of incident high-energy radiation can explain the dichotomy in variability behavior of RFe.Comment: 27 pages, 9 figures, accepted by A&

Disparities in the analysis of morphological disparity

Analyses of morphological disparity have been used to characterize and investigate the evolution of variation in the anatomy, function and ecology of organisms since the 1980s. While a diversity of methods have been employed, it is unclear whether they provide equivalent insights. Here, we review the most commonly used approaches for characterizing and analysing morphological disparity, all of which have associated limitations that, if ignored, can lead to misinterpretation. We propose best practice guidelines for disparity analyses, while noting that there can be no ‘one-size-fits-all’ approach. The available tools should always be used in the context of a specific biological question that will determine data and method selection at every stage of the analysis

Flat-spectrum symmetric objects with ~1 kpc sizes I. The candidates

In order to understand the origin and evolution of radio galaxies, searches for the youngest such sources have been conducted. Compact-medium symmetric objects (CSO-MSOs) are thought to be the earliest stages of radio sources, with possible ages of <10^3 yrs for CSOs (<1 kpc in size) and 10^4-10^5 yrs for MSOs (1-15 kpc). From a literature selection in heterogeneous surveys, we have established a sample of 37 confirmed CSOs. In addition, we only found three confirmed flat-spectrum MSOs in the literature. The typical CSO resides on a z<0.5 galaxy, has a flat radio spectrum (a_thin<0.5; S_v proportional to v^-a), is <0.3 kpc in size, has an arm length ratio <2, and well-aligned (theta<20 deg) opposite lobes with a flux density ratio <10. In order to populate the 0.3-1 kpc size range (large CSOs) and also in order to find more flat-spectrum MSOs, we have built a sample of 157 radio sources with a_{1.40}^{4.85}<0.5 that were resolved with the VLA-A 8.4 GHz. As first results, we have 'rediscovered' nine of the known CSO/MSOs while identifying two new ~14 kpc MSOs and two candidate CSO/MSOs (which only lack redshifts for final classification). We were able to reject 61 of the remaining 144 objects from literature information alone. In the series of papers that starts with this one we plan to classify the remaining 83 CSO/MSO candidates (thanks to radio and optical observations) as well as characterize the physical properties of the (likely) many 0.3-15 kpc flat-spectrum CSO/MSOs to be found.Comment: 19 pages, 14 figures, 6 tables (note that Table 2, in landscape format, has a separate file); accepted by MNRA

(Re) Locating community in relationships: questions for public policy

This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this record.This paper argues that we should think of community as being about social relationships rather than a ‘thing’ that is ‘lost’, ‘found’ or ‘made’. The paper draws on the philosophy of Roberto Esposito and the sociology of David Studdert to highlight the overlaps in their approaches to community. Both argue that community is ontological, as unavoidably ‘with us’. The paper then draws upon two empirical examples to argue that this approach could enable a different kind of public policy in relation to community. Policy would focus on existing relationships as the starting point for any efforts to effect social change. The implications for contemporary debates about localism are explored at the end of the paper.I am very grateful to David Studdert and Valerie Walkerdine for inviting me to the workshop on community and localism held at Cardiff University in April 2014 that stimulated this special issue of Sociological Review. I am also very grateful to the Leverhulme Trust for the research funding and to Nick Coke, Tessy Britton and Laura Billings for their invaluable contributions to the arguments made. The comments from three referees, the editors and Patrick Devine-Wright were extremely helpful in improving the paper

The geo-constitution: Understanding the intersection of geography and political institutions

This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this record.This paper draws on existing work in the discipline of human geography and cognate fields in order to develop the concept of the ‘geo-constitution’. This concept aims to: (1) highlight the importance of intersections between geography and political institutions in the constitution of government; (2) consider the path-dependent development of political institutions and their impact on statecraft and citizenship; (3) explore the implications of this for political reform. The paper provides an overview of current thinking in political geography and applies the concept of the geo-constitution to the example of devolution and localism in the United Kingdom

Film remakes, the black sheep of translation

Film remakes have often been neglected by translation studies in favour of other forms of audiovisual translation such as subtitling and dubbing. Yet, as this article will argue, remakes are also a form of cinematic translation. Beginning with a survey of previous, ambivalent approaches to the status of remakes, it proposes that remakes are multimodal, adaptive translations: they translate the many modes of the film being remade and offer a reworking of that source text. The multimodal nature of remakes is explored through a reading of Breathless, Jim McBride's 1983 remake of Jean-Luc Godard's À bout de souffle (1959), which shows how remade films may repeat the narrative of, but differ on multiple levels from, their source films. Due to the collaborative nature of film production, remakes involve multiple agents of translation. As such, remakes offer an expanded understanding of audiovisual translation