Mental Number Representations are Spatially Mapped both by Their Magnitudes and Ordinal Positions

One of the most fundamental effects used to investigate number representations is the Spatial-Numerical Association of Response Codes (SNARC) effect showing that responses to small/large numbers are faster with the left/right hand, respectively. However, in recent years, it is hotly debated whether the SNARC effect is based upon cardinal representation of number magnitude or ordinal representation of number sequence in working memory. However, one problem is that evidence comes from different paradigms, e.g., evidence for ordinal sequences comes usually from experiments, where ordinal sequences have to be learnt and it has been ar-gued that this secondary task triggers the effect. Therefore, in this preregistered study we em-ployed a SNARC task, without secondary ordinal sequence learning, in which we can dissociate ordinal and magnitude accounts by careful manipulation of experimental stimulus sets and com-pare magnitude and ordinal models. The results indicate that even though the observed data is better accounted for by the magnitude model, the ordinal position seems to matter as well. Thus, it appears that the mechanisms described by both accounts play a significant role when mental numbers are temporarily mapped onto space even when no ordinal learning is involved.

Encoding Numbers in the Context of Multiple Overlapping Cues: Evidence from a Chinese Finger Number Cognition Study

How people encode numbers in the context of multiple overlapping encoded cues remains unclear. In this study, we explored Chinese finger numbers, which contain both a numerical magnitude cue and a left-right hand cue offered by the expressing hand, to investigate the number encoding mechanism in the context of multiple overlapping cues. Chinese finger numbers expressed by the left or right hand were randomly and centrally presented on a computer screen to participants who were asked to perform a hand classification task (Experiment 1), a magnitude classification task (Experiment 2), a parity classification task (Experiment 3) and a magnitude classification or ring classification task (Experiment 4). We discovered (a) only an association effect between the pressed key and the expressing hand in hand classification and parity classification tasks, (b) the SNARC effect only on the magnitude classification task, (c) the association effect between the pressed key and the expressing hand on the larger, Chinese finger number, magnitude classification task in Experiment 2, and (d) the SNARC effect and the association between the pressed key and the expressing hand were reversed on the ring classification task. From these results, we concluded that people can flexibly choose appropriate number encoding cues and how numbers are encoded in the context of multiple overlapping cues depending on (a) which cognition task individuals perform and (b) the character of the numbers involved.

Evolution and characteristics of frequency, duration and magnitude of drought events in the central Pyrenees since 1940

<p>The central sectors of the Pyrenees have experienced a significant increase in the average and extreme daily temperature during the last 80 years, as well as a downward trend in precipitation totals (Perez-Zanón et al., 2016). This article addresses the evolution of the number, magnitude and duration of drought events in the Spanish Central Pyrenees from 8 decades of temperature and precipitation records integrated into the high-quality Central Pyrenees data set (Perez-Zanón et al., 2016 ), using the Standardised Precipitation-Evapotranspiration Index (SPEI) index (Begueria et al., 2014; Vicente-Serrano et al., 2010). Series of monthly mean temperature, monthly maximum temperature, monthly minimum temperature and accumulated monthly precipitation corresponding to 15 quality controlled and homogeneity adjusted meteorological observatories have been used. This index has been calculated for 3, 6, 12 and 24 months, in order to analyse its behaviour ​​for different types of drought.</p><p>The analysis of SPEI index series indicates a tendency to increase in the frequency of drought events and in their maximum magnitude in the 4 time scales of the SPEI index analysed, especially since the 1980s. This increase in the number of events is also accompanied by an increase in their duration, especially in the case of SPEI3 and SPEI6, although not in the case of SPEI12 and SPEI24</p><p>The spatial patterns calculated from the series of the indices also show a clear east-west pattern differentiated between the index signal for the eastern Pyrenees and the western Pyrenees.</p><p>REFERENCES</p><p>Beguería, S., Vicente-Serrano, S.M., Fergus Reig, Borja Latorre. Standardized Precipitation Evapotranspiration Index (SPEI) revisited (2014): parameter fitting, evapotranspiration models, kernel weighting, tools, datasets and drought monitoring. International Journal of Climatology, 34: 3001-3023</p><p>Pérez-Zanón, N., Sigró, J. and Ashcroft, L. (2016), Temperature and precipitation regional climate series over the central Pyrenees during 1910–2013. Int. J. Climatol. DOI:10.1002/joc.4823</p><p>Vicente-Serrano S.M., Santiago Beguería, Juan I. López-Moreno, (2010) A Multi-scalar drought index sensitive to global warming: The Standardized Precipitation Evapotranspiration Index - SPEI. Journal of Climate 23: 1696-1718.</p>

Analysis of Buongiorno’s nanofluid model in marangoni convective flow with gyrotactic microorganism and activation energy

This communication is to analyze the Marangoni convection MHD flow of nanofluid. Marangoni convection is very useful physical phenomena in presence of microgravity conditions which is generated by gradient of surface tension at interface. We have also studied the swimming of migratory gyrotactic microorganisms in nanofluid. Flow is due to rotation of disk. Heat and mass transfer equations are examined in detail in the presence of heat source sink and Joule heating. Nonlinear mixed convection effect is inserted in momentum equation. Appropriate transformations are applied to find system of equation. HAM technique is used for convergence of equations. Radial and axial velocities, concentration, temperature, motile microorganism profile, Nusselt number and Sherwood number are sketched against important parameters. Marangoni ratio parameter and Marangoni number are increasing functions of axial and radial velocities. Temperature rises for Marangoni number and heat source sink parameter. Activation energy and chemical reaction rate parameter have opposite impact on concentration profile. Motile density profile decays via Peclet number and Schmidt number. Magnitude of Nusselt number enhances via Marangoni ratio parameter.

The Force of Numbers: Investigating Manual Signatures of Embodied Number Processing

The study has two objectives: (1) to introduce grip force recording as a new technique for studying embodied numerical processing; and (2) to demonstrate how three competing accounts of numerical magnitude representation can be tested by using this new technique: the Mental Number Line (MNL), A Theory of Magnitude (ATOM) and Embodied Cognition (finger counting-based) account. While 26 healthy adults processed visually presented single digits in a go/no-go n-back paradigm, their passive holding forces for two small sensors were recorded in both hands. Spontaneous and unconscious grip force changes related to number magnitude occurred in the left hand already 100–140 ms after stimulus presentation and continued systematically. Our results support a two-step model of number processing where an initial stage is related to the automatic activation of all stimulus properties whereas a later stage consists of deeper conscious processing of the stimulus. This interpretation generalizes previous work with linguistic stimuli and elaborates the timeline of embodied cognition. We hope that the use of grip force recording will advance the field of numerical cognition research.

Spatial–numerical associations in the presence of an avatar

When we interact with other people or avatars, they often provide an alternative spatial frame of reference compared to our own. Previous studies introduced avatars into stimulus–response compatibility tasks and demonstrated compatibility effects as if the participant was viewing the task from the avatar’s point of view. However, the origin of this effect of perspective taking remained unclear. To distinguish changes in stimulus coding from changes in response coding, caused by the avatar, two experiments were conducted that combined a SNARC task and a spontaneous visual perspective taking task to specify the role of response coding. We observed compatibility effects that were based on the avatar’s perspective rather than the participants’ own. Because number magnitude was independent of the avatar’s perspective, the observed changes in compatibility caused by different perspectives indicate changes in response coding. These changes in response coding are only significant when they are accompanied by visual action effects.

Observation and control of maximal Chern numbers in a chiral topological semimetal

Topological semimetals feature protected nodal band degeneracies characterized by a topological invariant known as the Chern number (C). Nodal band crossings with linear dispersion are expected to have at most |C|=4, which sets an upper limit to the magnitude of many topological phenomena in these materials. Here, we show that the chiral crystal palladium gallium (PdGa) displays multifold band crossings, which are connected by exactly four surface Fermi arcs, thus proving that they carry the maximal Chern number magnitude of 4. By comparing two enantiomers, we observe a reversal of their Fermi-arc velocities, which demonstrates that the handedness of chiral crystals can be used to control the sign of their Chern numbers.