Exploring modality switching effects in negated sentences: further evidence for grounded representations

Theories of embodied cognition (e.g., Perceptual Symbol Systems Theory; Barsalou, 1999, 2009) suggest that modality specific simulations underlie the representation of concepts. Supporting evidence comes from modality switch costs: participants are slower to verify a property in one modality (e.g., auditory, BLENDER-loud) after verifying a property in a different modality (e.g., gustatory, CRANBERRIES-tart) compared to the same modality (e.g., LEAVES-rustling, Pecher et al., 2003). Similarly, modality switching costs lead to a modulation of the N400 effect in event-related potentials (ERPs; Collins et al., 2011; Hald et al., 2011). This effect of modality switching has also been shown to interact with the veracity of the sentence (Hald et al., 2011). The current ERP study further explores the role of modality match/mismatch on the processing of veracity as well as negation (sentences containing “not”). Our results indicate a modulation in the ERP based on modality and veracity, plus an interaction. The evidence supports the idea that modality specific simulations occur during language processing, and furthermore suggest that these simulations alter the processing of negation

The Potential For UK Portfolio Investors To Finance Sustainable Tropical Forestry

Environmental Economics and Policy, Resource /Energy Economics and Policy,

Effects of shade and predation on survival and growth of larval gray treefrogs (hyla versicolor) [abstract]

Abstract only availableAmphibians are experiencing population reductions and species extinctions on a worldwide scale and most biologists agree that loss or degradation of local habitats is the major factor causing declines. As part of the larger Land-use Effects on Amphibian Populations (LEAP) project, we examined some of the effects of timber harvest on the pond environment of larval gray treefrogs (Hyla versicolor). We manipulated shade and predator levels (dragonfly larvae; family Libellulidae) in cattle tanks to test the impact of clear-cutting on the tadpole populations. Survival and size of the metamorphosed frogs differed in response to shade and predation level, but larval period was unaffected. The percent survival in low shade treatments was 71.0% compared to 65.7% for high shade treatments and average mass at metamorphosis was 0.3347 g compared to 0.2960 g. This greater growth was supported by previous research and suggests open canopy ponds have more periphyton which tadpoles utilize as food. In the predator treatments, ponds that had no dragonfly larvae had a greater percent survival than the high predator density ponds (81.2% and 61.8%), however, the average mass of the zero and high predator treatments were similar and smaller than masses in the low and medium treatments. The smaller size at metamorphosis in the high predator treatments can be attributed to reduced feeding activity in order to avoid predators. The higher survival rate from the lack of predation in low treatments resulted in greater tadpole density and less resources available resulting in smaller average mass at metamorphosis. These results imply that clear-cutting does not negatively impact amphibian populations because the tadpoles seemed to thrive from the benefits of open canopy ponds. However, this is the only the first stage in their life history and would probably differ in canopy preference as the frogs mature and begin to use trees for refugia.McNair Scholars Progra

Modality switching and negation: ERP evidence for modality-specific simulations during negation processing

The Perceptual Symbol System Theory of cognition (Barsalou, 1999) suggests that modality-specific simulations underlie representation of concepts. This is evidenced by processing costs for switching modalities. That is, participants are slower to verify a property in the auditory modality (e.g., BLENDER-loud) after verifying a property in a different modality (e.g., CRANBERRIES-tart) and faster when verifying a property in the same modality (e.g., LEAVES-rustling). The modality switch cost has also been shown to lead to a modulation of the N400 event-related potential (ERP) (Collins, Pecher, Zeelenberg & Coulson, 2011 using a property verification task; Hald, Marshall, Janssen & Garnham, 2011 using a sentence verification task). In a separate line of research, ERP studies have indicated that without a discourse context, negated sentences are more difficult to process than affirmative sentences, leading to a different N400 pattern for negative sentences than for affirmative sentences (e.g., Fischler, Bloom, Childers, Roucos, & Perry, 1983.) Unlike affirmative sentences, sentences containing negation show a larger N400 for correct, semantically coherent single sentences (i.e., factually true sentences) than for semantically incorrect sentences (i.e., false sentences). However, Nieuwland and Kuperberg (2008,) found that the pragmatics of the sentence can change this N400 pattern to one closer to affirmative sentences. The goal of the current study was to explore whether the processing of negation could be aided by modality matching information. Other evidence suggests that comprehenders create a simulation of negative sentences (Kaup, Yaxley, Madden, Zwaan, & Lüdtke, 2007), but it is unclear whether modality matching information could modulate the processing cost of negation. Essentially, can modality matching information as reported by Collins et al., (2011) and Hald et al., (2011) lead to a modulation of the N400 for true negated sentences similar to that seen when discourse pragmatics supports negation? Furthermore, we were interested in whether the modality switch effect would lead to a similar pattern in the ERPs as that found with affirmative sentences (Collins et al., 2011 & Hald et al., 2011). Using a within-subjects design we used 160 pairs of experimental pairs which were either of the same or of a different modality. All experimental items were either visual or tactile modality and were drawn from existing sets of materials (Pecher, et al., 2003; Van Dantzig, et al., 2008). For example, a different modality pair was “A light bulb is very hot” followed by “Rice isn’t black” versus a same visual modality pair “A giraffe is spotted” followed by “Rice isn’t black”. We predicted that the underlined word is where a modulation in the N400 may be seen. Additionally, we explored veracity by making half of the experimental target sentences false (“Rice isn’t white”). Participants were asked to judge whether each sentence was typically true or false. Our initial results indicate a modulation in the ERP based on both modality and veracity. For true (“Rice isn’t black”) and false target statements (“Rice isn’t white”) different modality pairs elicit a larger frontal-central N400 like effect compared to same modality pairs (Figure 1), replicating Hald et al., (2011). When comparing true versus false, the different modality pairs elicit a large posterior N400 for true compared to false sentences (replicating the effect for negated sentences, i.e., Fischler et al., 1983). However for same modality pairs there is a reduction in the N400 to true statements; no difference is seen between true and false statements in the ERP (Figure 2). These results replicate and extend previous ERP findings using the modality switch paradigm. The evidence suggests that not only do modality-specific simulations occur but they can even aid the processing of negation

The Use of Reaction Kinetics in Classifying Alkali Silica Reactivity Potential of Aggregates

The Australian Standard accelerated mortar bar test (AMBT) method, AS 1141.60.1, adopts the expansion limits at two exposure periods to classify the alkali silica reactivity (ASR) of aggregate. This was a first step toward the use of ‘reaction kinetics’ or ‘rate of reaction’ to detect and classify alkali silica reactivity. The AS 1141.60.2 concrete prism test (CPT), on the other hand, uses a single expansion limit at one year to classify ASR. This paper examines the validity of the use of reaction kinetics, evaluated from the AMBT expansion data, to gauge and classify the reactivity. This may enable a better quantification of the degrees of reactivity and a more fundamental approach to ASR mitigatio

Particle size segregation in granular flow in silos

Segregation and layering of alumina in storage silos are investigated, with a view to predicting output quality versus time, given known variations in input quality on emplacement. A variety of experiments were conducted, existing relevant publications were reviewed, and the basis for an algorithm for predicting the effect of withdrawing from a central flowing region, in combination with variations in quality due to geometric, layering and segregation effects, is described in this report

Assessment of Gravity Wave Momentum Flux Measurement Capabilities by Meteor Radars Having Different Transmitter Power and Antenna Configurations

Measurement capabilities of five meteor radars are assessed and compared to determine how well radars having different transmitted power and antenna configurations perform in defining mean winds, tidal amplitudes, and gravity wave (GW) momentum fluxes. The five radars include two new-generation meteor radars on Tierra del Fuego, Argentina (53.8 deg S) and on King George Island in the Antarctic (62.1 deg S) and conventional meteor radars at Socorro, New Mexico (34.1 deg N, 106.9 deg W), Bear Lake Observatory, Utah (approx 41.9 deg N, 111.4 deg W), and Yellowknife, Canada (62.5 deg N, 114.3 deg W). Our assessment employs observed meteor distributions for June of 2009, 2010, or 2011 for each radar and a set of seven test motion fields including various superpositions of mean winds, constant diurnal tides, constant and variable semidiurnal tides, and superposed GWs having various amplitudes, scales, periods, directions of propagation, momentum fluxes, and intermittencies. Radars having higher power and/or antenna patterns yielding higher meteor counts at small zenith angles perform well in defining monthly and daily mean winds, tidal amplitudes, and GW momentum fluxes, though with expected larger uncertainties in the daily estimates. Conventional radars having lower power and a single transmitting antenna are able to describe monthly mean winds and tidal amplitudes reasonably well, especially at altitudes having the highest meteor counts. They also provide qualitative estimates of GW momentum fluxes at the altitudes having the highest meteor counts; however, these estimates are subject to uncertainties of approx 20 to 50% and uncertainties rapidly become excessive at higher and lower altitudes. Estimates of all quantities degrade somewhat for more complex motion fields

Hydrodynamic theory of de-wetting

A prototypical problem in the study of wetting phenomena is that of a solid plunging into or being withdrawn from a liquid bath. In the latter, de-wetting case, a critical speed exists above which a stationary contact line is no longer sustainable and a liquid film is being deposited on the solid. Demonstrating this behavior to be a hydrodynamic instability close to the contact line, we provide the first theoretical explanation of a classical prediction due to Derjaguin and Levi: instability occurs when the outer, static meniscus approaches the shape corresponding to a perfectly wetting fluid

Simulating the effects of mid- to upper-tropospheric clouds on microwave emissions in EC-Earth using COSP

In this work, the Cloud Feedback Model Intercomparison (CFMIP) Observation Simulation Package (COSP) is expanded to include scattering and emission effects of clouds and precipitation at passive microwave frequencies. This represents an advancement over the official version of COSP (version 1.4.0) in which only clear-sky brightness temperatures are simulated. To highlight the potential utility of this new microwave simulator, COSP results generated using the climate model EC-Earth's version 3 atmosphere as input are compared with Microwave Humidity Sounder (MHS) channel (190.311 GHz) observations. Specifically, simulated seasonal brightness temperatures (TB) are contrasted with MHS observations for the period December 2005 to November 2006 to identify possible biases in EC-Earth's cloud and atmosphere fields. The EC-Earth's atmosphere closely reproduces the microwave signature of many of the major large-scale and regional scale features of the atmosphere and surface. Moreover, greater than 60 % of the simulated TB are within 3 K of the NOAA-18 observations. However, COSP is unable to simulate sufficiently low TB in areas of frequent deep convection. Within the Tropics, the model's atmosphere can yield an underestimation of TB by nearly 30 K for cloudy areas in the ITCZ. Possible reasons for this discrepancy include both incorrect amount of cloud ice water in the model simulations and incorrect ice particle scattering assumptions used in the COSP microwave forward model. These multiple sources of error highlight the non-unique nature of the simulated satellite measurements, a problem exacerbated by the fact that EC-Earth lacks detailed micro-physical parameters necessary for accurate forward model calculations. Such issues limit the robustness of our evaluation and suggest a general note of caution when making COSP-satellite observation evaluations

Topological constraints on spiral wave dynamics in spherical geometries with inhomogeneous excitability

We analyze the way topological constraints and inhomogeneity in the excitability influence the dynamics of spiral waves on spheres and punctured spheres of excitable media. We generalize the definition of an index such that it characterizes not only each spiral but also each hole in punctured, oriented, compact, two-dimensional differentiable manifolds and show that the sum of the indices is conserved and zero. We also show that heterogeneity and geometry are responsible for the formation of various spiral wave attractors, in particular, pairs of spirals in which one spiral acts as a source and a second as a sink -- the latter similar to an antispiral. The results provide a basis for the analysis of the propagation of waves in heterogeneous excitable media in physical and biological systems.Comment: 5 pages, 6 Figures, major revisions, accepted for publication in Phys. Rev.