130 research outputs found
Do synaesthesia and mental imagery tap into similar cross-modal processes?
Synaesthesia has previously been linked with imagery abilities, although an understanding of a causal role for mental imagery in broader synaesthetic experiences remains elusive. This can be partly attributed to our relatively poor understanding of imagery in sensory domains beyond vision. Investigations into the neural and behavioural underpinnings of mental imagery have nevertheless identified an important role for imagery in perception, particularly in mediating cross-modal interactions. However, the phenomenology of synaesthesia gives rise to the assumption that associated cross-modal interactions may be encapsulated and specific to synaesthesia. As such, evidence for a link between imagery and perception may not generalize to synaesthesia. Here, we present results that challenge this idea: first, we found enhanced somatosensory imagery evoked by visual stimuli of body parts in mirror-touch synaesthetes, relative to other synaesthetes or controls. Moreover, this enhanced imagery generalized to tactile object properties not directly linked to their synaesthetic associations. Second, we report evidence that concurrent experience evoked in grapheme-colour synaesthesia was sufficient to trigger visual-to-tactile correspondences that are common to all. Together, these findings show that enhanced mental imagery is a consistent hallmark of synaesthesia, and suggest the intriguing possibility that imagery may facilitate the cross-modal interactions that underpin synaesthesic experiences. This article is part of a discussion meeting issue 'Bridging senses: novel insights from synaesthesia'
Neutron Stars in f(R) Gravity with Perturbative Constraints
We study the structure of neutron stars in f(R) gravity theories with
perturbative constraints. We derive the modified Tolman-Oppenheimer-Volkov
equations and solve them for a polytropic equation of state. We investigate the
resulting modifications to the masses and radii of neutron stars and show that
observations of surface phenomena alone cannot break the degeneracy between
altering the theory of gravity versus choosing a different equation of state of
neutron-star matter. On the other hand, observations of neutron-star cooling,
which depends on the density of matter at the stellar interior, can place
significant constraints on the parameters of the theory.Comment: Discussion extended, typos corrected, figures revised. Accepted for
publication in PR
Modeling Global Warming Scenarios in Greenback Cutthroat Trout (\u3cem\u3eOncorhynchus Clarki Stomias\u3c/em\u3e) Streams: Implications for Species Recovery
Changes in global climate may exacerbate other anthropogenic stressors, accelerating the decline in distribution and abundance of rare species throughout the world. We examined the potential effects of a warming climate on the greenback cutthroat trout (Oncorhynchus clarki stomias), a resident salmonid that inhabits headwater streams of the central Rocky Mountains. Greenbacks are outcompeted at lower elevations by nonnative species of trout and currently are restricted to upper-elevation habitats where barriers to upstream migration by nonnatives are or have been established. We used likelihood-based techniques and information theoretics to select models predicting stream temperature changes for 10 streams where greenback cutthroat trout have been translocated. These models showed high variability among responses by different streams, indicating the usefulness of a stream-specific approach. We used these models to project changes in stream temperatures based on 2°C and 4°C warming of average air temperatures. In these warming scenarios, spawning is predicted to begin from 2 to 3.3 weeks earlier than would be expected under baseline conditions. Of the 10 streams used in this assessment, 5 currently have less than a 50% chance of translocation success. Warming increased the probability of translocation success in these 5 streams by 11.2% and 21.8% in the 2 scenarios, respectively. Assuming barriers to upstream migration by nonnative competitors maintain their integrity, we conclude that an overall habitat improvement results because greenbacks have been restricted through competition with nonnatives to suboptimal habitats, which are generally too cold to be highly productive
The development of visuotactile congruency effects for sequences of events.
Abstract Sensitivity to the temporal coherence of visual and tactile signals increases perceptual reliability and is evident during infancy. However, it is not clear how, or whether, bidirectional visuotactile interactions change across childhood. Furthermore, no study has explored whether viewing a body modulates how children perceive visuotactile sequences of events. Here, children aged 5–7 years (n = 19), 8 and 9 years (n = 21), and 10–12 years (n = 24) and adults (n = 20) discriminated the number of target events (one or two) in a task-relevant modality (touch or vision) and ignored distractors (one or two) in the opposing modality. While participants performed the task, an image of either a hand or an object was presented. Children aged 5–7 years and 8 and 9 years showed larger crossmodal interference from visual distractors when discriminating tactile targets than the converse. Across age groups, this was strongest when two visual distractors were presented with one tactile target, implying a "fission-like" crossmodal effect (perceiving one event as two events). There was no influence of visual context (viewing a hand or non-hand image) on visuotactile interactions for any age group. Our results suggest robust interference from discontinuous visual information on tactile discrimination of sequences of events during early and middle childhood. These findings are discussed with respect to age-related changes in sensory dominance, selective attention, and multisensory processing
The Unmaking of Marx’s Capital: Heinrich’s Attempt to Eliminate Marx’s Crisis Theory
Michael Heinrich’s recent Monthly Review article claims that the law of the tendential fall in the rate of profit (LTFRP) was not proved by Marx and cannot be proved. Heinrich also argues that Marx had doubts about the law and that, for this and other reasons, his theory of capitalist economic crisis was only provisional and more or less in continual flux.
This response shows that Heinrich’s elementary misunderstanding of the law––his belief that it is meant to predict what must inevitably happen rather than to explain what does happen––is the source of his charge that it is unproved. It then shows that a simple misreading of Marx’s text lies at the basis of Heinrich’s claim that the simplest version of the LTFRP, “the law as such,” is a failure. Marx’s argument that increases in the rate of surplus-value cannot “cancel” the fall in the rate of profit is then defended against Heinrich’s attempt to refute it. Finally, the paper presents evidence that Marx was indeed convinced that the LTFRP is correct and that he regarded the crisis theory of volume 3 of Capital as finished in a theoretical sense
The Unmaking of Marx’s Capital: Heinrich’s Attempt to Eliminate Marx’s Crisis Theory
Michael Heinrich’s recent Monthly Review article claims that the law of the tendential fall in the rate of profit (LTFRP) was not proved by Marx and cannot be proved. Heinrich also argues that Marx had doubts about the law and that, for this and other reasons, his theory of capitalist economic crisis was only provisional and more or less in continual flux.
This response shows that Heinrich’s elementary misunderstanding of the law––his belief that it is meant to predict what must inevitably happen rather than to explain what does happen––is the source of his charge that it is unproved. It then shows that a simple misreading of Marx’s text lies at the basis of Heinrich’s claim that the simplest version of the LTFRP, “the law as such,” is a failure. Marx’s argument that increases in the rate of surplus-value cannot “cancel” the fall in the rate of profit is then defended against Heinrich’s attempt to refute it. Finally, the paper presents evidence that Marx was indeed convinced that the LTFRP is correct and that he regarded the crisis theory of volume 3 of Capital as finished in a theoretical sense
A smart city-smart bay project - establishing an integrated water monitoring system for decision support in Dublin Bay
Environmental and water quality monitoring is key to measuring and understanding the chemical and biological quality of water and for taking reactive remedial action. Over the coming years, monitoring of water bodies will increase within Europe, in order to comply with the requirements of the Water Framework Directive (WFD, Council Directive 2000/60/EC), and globally owing to pressure from climate change. The establishment of high quality long-term monitoring programmes is regarded as essential if the implementation of the WFD is to be effective. However, the traditional spot/grab sampling using conventional sampling and laboratory based techniques can introduce a significant financial burden, and is unlikely to provide a reasonable estimate of the true maximum and/or mean concentration for a particular physico-chemical variable in a water body with marked temporal variability. When persistent fluctuations occur, it is likely only to be detected through continuous measurements, which have the capability of detecting sporadic peaks of concentration. The aim of this work is to demonstrate the potential for continuous monitoring data in decision support as part of a smart city project. The multi-modal data system shows potential for low-cost sensing in complex aquatic environments around the city. Continuous monitoring data from both visual and water quality sensors is collected and data from grab samples collected support the observations of trends in water quality
Modeling Collisional Cascades In Debris Disks: The Numerical Method
We develop a new numerical algorithm to model collisional cascades in debris
disks. Because of the large dynamical range in particle masses, we solve the
integro-differential equations describing erosive and catastrophic collisions
in a particle-in-a-box approach, while treating the orbital dynamics of the
particles in an approximate fashion. We employ a new scheme for describing
erosive (cratering) collisions that yields a continuous set of outcomes as a
function of colliding masses. We demonstrate the stability and convergence
characteristics of our algorithm and compare it with other treatments. We show
that incorporating the effects of erosive collisions results in a decay of the
particle distribution that is significantly faster than with purely
catastrophic collisions.Comment: 24 pages, 20 figues, Published in Ap
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