141 research outputs found

    Dissociating recollection from familiarity: electrophysiological evidence that familiarity for faces is associated with a posterior old/new effect

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    In recognition memory research, a tension exists between dual-process and single-process models of episodic retrieval. Dual-process models propose that ‘familiarity’ assessment and the ‘recollection’ of contextual information are independent processes, while single process models claim that one common process supports retrieval. Event-related potentials (ERPs) have been used to show dissociations between the mid frontal and the left parietal ERP old/new effects, which have been associated with familiarity and recollection, respectively. While much ERP evidence favours dual-process theory, Yovel and Paller (2004) used faces as retrieval cues to demonstrate that posterior old/new effects index both familiarity and recollection, a finding consistent with single process models. Here we present evidence supporting Yovel and Paller’s claim that a posterior old/new effect indexes familiarity for faces, along with a novel finding that recollection is associated with an anterior old/new effect. Importantly, and in contrast to Yovel and Paller, the old/new effects associated with familiarity and recollection were topographically dissociable, consistent with a dual process view of recognition memory. The neural correlates of familiarity and recollection identified here for faces appear to be different from those typically observed, suggesting that the ERP old/new effects associated with episodic recognition are not the same under all circumstances

    Reyes, acreedores y conversos: el impacto de la política real y de la deuda corporativa en la identidad colectiva de los conversos de Mallorca después de 1391

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    Royal correspondence of the Kingdom of Majorca reveals that “external” economic factors and royal policies forced the first generations of 1391 conversos to remain a distinct social group. Not long after the anti-Jewish violence and mass conversions of 1391, the conversos of Majorca granted a percentage of their assets to King Joan I. At the same time, the conversos and surviving Jews had to repay the creditors of the former aljama, which had been dissolved following the attack against the Jewish quarter. These two collective financial obligations required the conversos to organize themselves as a group, following the precedent of the aljama, with elected leaders who organized an internal tax collection in order to pay these debts, and who lobbied on behalf of the conversos before the king and before their creditors. This administrative structure set the foundation for the converso confraternity of Sant Miquel, founded in 1404.Un examen detallado de la correspondencia real relativa a Mallorca muestra que factores económicos «externos» y directivas políticas reales obligaron a la primera generación de conversos de 1391 a permanecer como grupo social distintivo. Poco después de producirse la violencia anti-judía y las conversiones masivas de 1391, los conversos de Mallorca tuvieron que otorgar un porcentaje de sus propiedades al rey Juan I. Al mismo tiempo, conversos y judíos supervivientes debían seguir pagando los «censalers» de la aljama de judíos que había sido disuelta tras el ataque en 1391 contra la judería. Estas dos obligaciones financieras colectivas obligaron a los conversos a organizarse, siguiendo el precedente de la aljama, como grupo con líderes elegidos que administraron la colección fiscal interna a fin de pagar esas deudas, e interviniendo a favor de los conversos ante el rey y sus acreedores. Esta estructura administrativa puso los fundamentos de la cofradía conversa de Sant Miquel, establecida en 1404

    Cognitive and behavioral predictors of light therapy use

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    Objective: Although light therapy is effective in the treatment of seasonal affective disorder (SAD) and other mood disorders, only 53-79% of individuals with SAD meet remission criteria after light therapy. Perhaps more importantly, only 12-41% of individuals with SAD continue to use the treatment even after a previous winter of successful treatment. Method: Participants completed surveys regarding (1) social, cognitive, and behavioral variables used to evaluate treatment adherence for other health-related issues, expectations and credibility of light therapy, (2) a depression symptoms scale, and (3) self-reported light therapy use. Results: Individuals age 18 or older responded (n = 40), all reporting having been diagnosed with a mood disorder for which light therapy is indicated. Social support and self-efficacy scores were predictive of light therapy use (p's<.05). Conclusion: The findings suggest that testing social support and self-efficacy in a diagnosed patient population may identify factors related to the decision to use light therapy. Treatments that impact social support and self-efficacy may improve treatment response to light therapy in SAD. © 2012 Roecklein et al

    Face Inversion Reduces the Persistence of Global Form and Its Neural Correlates

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    Face inversion produces a detrimental effect on face recognition. The extent to which the inversion of faces and other kinds of objects influences the perceptual binding of visual information into global forms is not known. We used a behavioral method and functional MRI (fMRI) to measure the effect of face inversion on visual persistence, a type of perceptual memory that reflects sustained awareness of global form. We found that upright faces persisted longer than inverted versions of the same images; we observed a similar effect of inversion on the persistence of animal stimuli. This effect of inversion on persistence was evident in sustained fMRI activity throughout the ventral visual hierarchy, including the lateral occipital area (LO), two face-selective visual areas—the fusiform face area (FFA) and the occipital face area (OFA)—and several early visual areas. V1 showed the same initial fMRI activation to upright and inverted forms but this activation lasted longer for upright stimuli. The inversion effect on persistence-related fMRI activity in V1 and other retinotopic visual areas demonstrates that higher-tier visual areas influence early visual processing via feedback. This feedback effect on figure-ground processing is sensitive to the orientation of the figure

    Left gaze bias in humans, rhesus monkeys and domestic dogs

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    While viewing faces, human adults often demonstrate a natural gaze bias towards the left visual field, that is, the right side of the viewee’s face is often inspected first and for longer periods. Using a preferential looking paradigm, we demonstrate that this bias is neither uniquely human nor limited to primates, and provide evidence to help elucidate its biological function within a broader social cognitive framework. We observed that 6-month-old infants showed a wider tendency for left gaze preference towards objects and faces of different species and orientation, while in adults the bias appears only towards upright human faces. Rhesus monkeys showed a left gaze bias towards upright human and monkey faces, but not towards inverted faces. Domestic dogs, however, only demonstrated a left gaze bias towards human faces, but not towards monkey or dog faces, nor to inanimate object images. Our findings suggest that face- and species-sensitive gaze asymmetry is more widespread in the animal kingdom than previously recognised, is not constrained by attentional or scanning bias, and could be shaped by experience to develop adaptive behavioural significance

    From upright to upside-down presentation: A spatio-temporal ERP study of the parametric effect of rotation on face and house processing

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    <p>Abstract</p> <p>Background</p> <p>While there is a general agreement that picture-plane inversion is more detrimental to face processing than to other seemingly complex visual objects, the origin of this effect is still largely debatable. Here, we address the question of whether face inversion reflects a quantitative or a qualitative change in processing mode by investigating the pattern of event-related potential (ERP) response changes with picture plane rotation of face and house pictures. Thorough analyses of topographical (Scalp Current Density maps, SCD) and dipole source modeling were also conducted.</p> <p>Results</p> <p>We find that whilst stimulus orientation affected in a similar fashion participants' response latencies to make face and house decisions, only the ERPs in the N170 latency range were modulated by picture plane rotation of faces. The pattern of N170 amplitude and latency enhancement to misrotated faces displayed a curvilinear shape with an almost linear increase for rotations from 0° to 90° and a dip at 112.5° up to 180° rotations. A similar discontinuity function was also described for SCD occipito-temporal and temporal current foci with no topographic distribution changes, suggesting that upright and misrotated faces activated similar brain sources. This was confirmed by dipole source analyses showing the involvement of bilateral sources in the fusiform and middle occipital gyri, the activity of which was differentially affected by face rotation.</p> <p>Conclusion</p> <p>Our N170 findings provide support for both the quantitative and qualitative accounts for face rotation effects. Although the qualitative explanation predicted the curvilinear shape of N170 modulations by face misrotations, topographical and source modeling findings suggest that the same brain regions, and thus the same mechanisms, are probably at work when processing upright and rotated faces. Taken collectively, our results indicate that the same processing mechanisms may be involved across the whole range of face orientations, but would operate in a non-linear fashion. Finally, the response tuning of the N170 to rotated faces extends previous reports and further demonstrates that face inversion affects perceptual analyses of faces, which is reflected within the time range of the N170 component.</p

    Investigating the functional interaction between semantic and episodic memory: Convergent behavioral and electrophysiological evidence for the role of familiarity

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    Throughout our lives we acquire general knowledge about the world (semantic memory) while also retaining memories of specific events (episodic memory). Although these two forms of memory have been dissociated on the basis of neuropsychological data, it is clear that they typically function together during normal cognition. The goal of the present study was to investigate this interaction. One influence of semantic memory on episodic retrieval is ‘Levels Of Processing’; recognition is enhanced when stimuli are processed in a semantically meaningful way. Studies examining this semantic processing advantage have largely concluded that semantic memory augments episodic retrieval primarily by enhancing recollection. The present study provides strong evidence for an alternative relationship between semantic and episodic memory. We employed a manipulation of the semantic coherence of to-be-remembered information (semantically related vs. unrelated word pairs) during an associative recognition memory test. Results revealed that associative recognition is significantly enhanced for semantically coherent material, and behavioral estimates (using the process dissociation procedure) demonstrated concomitant changes in the contribution of familiarity to retrieval. Neuroimaging data (event-related potentials recorded at test) also revealed a significant increase in familiarity based retrieval. The electrophysiological correlate of familiarity (the mid-frontal ERP old/new effect) was larger for semantically related compared to unrelated word pairs, but no difference was present in the electrophysiological correlate of recollection (the left parietal old/new effect). We conclude that semantic memory and episodic memory do indeed interact in normal functioning, and not only by modulating recollection, but also by enhancing familiarity

    Picturing words? Sensorimotor cortex activation for printed words in child and adult readers

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    Learning to read involves associating abstract visual shapes with familiar meanings. Embodiment theories suggest that word meaning is at least partially represented in distributed sensorimotor networks in the brain (Barsalou, 2008; Pulvermueller, 2013). We explored how reading comprehension develops by tracking when and how printed words start activating these “semantic” sensorimotor representations as children learn to read. Adults and children aged 7–10 years showed clear category-specific cortical specialization for tool versus animal pictures during a one-back categorisation task. Thus, sensorimotor representations for these categories were in place at all ages. However, co-activation of these same brain regions by the visual objects’ written names was only present in adults, even though all children could read and comprehend all presented words, showed adult-like task performance, and older children were proficient readers. It thus takes years of training and expert reading skill before spontaneous processing of printed words’ sensorimotor meanings develops in childhood

    Diffusion MRI of Structural Brain Plasticity Induced by a Learning and Memory Task

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    Background: Activity-induced structural remodeling of dendritic spines and glial cells was recently proposed as an important factor in neuroplasticity and suggested to accompany the induction of long-term potentiation (LTP). Although T1 and diffusion MRI have been used to study structural changes resulting from long-term training, the cellular basis of the findings obtained and their relationship to neuroplasticity are poorly understood. Methodology/Principal Finding: Here we used diffusion tensor imaging (DTI) to examine the microstructural manifestations of neuroplasticity in rats that performed a spatial navigation task. We found that DTI can be used to define the selective localization of neuroplasticity induced by different tasks and that this process is age-dependent in cingulate cortex and corpus callosum and age-independent in the dentate gyrus. Conclusion/Significance: We relate the observed DTI changes to the structural plasticity that occurs in astrocytes and discuss the potential of MRI for probing structural neuroplasticity and hence indirectly localizing LTP

    Live birth rates and perinatal outcomes when all embryos are frozen compared with conventional fresh and frozen embryo transfer: a cohort study of 337,148 in vitro fertilisation cycles

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    BACKGROUND: It is not known whether segmentation of an in vitro fertilisation (IVF) cycle, with freezing of all embryos prior to transfer, increases the chance of a live birth after all embryos are transferred. METHODS: In a prospective study of UK Human Fertilisation and Embryology Authority data, we investigated the impact of segmentation, compared with initial fresh embryo followed by frozen embryo transfers, on live birth rate and perinatal outcomes. We used generalised linear models to assess the effect of segmentation in the whole cohort, with additional analyses within women who had experienced both segmentation and non-segmentation. We compared rates of live birth, low birthweight (LB
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