scholarly journals Whole-brain MEG decoding of symbolic and non-symbolic number stimuli reveals primarily format-dependent representations

2019 ◽  
Author(s):  
Brett B. Bankson ◽  
Daniel Janini ◽  
Chris I. Baker
Keyword(s):  
Classification Accuracy ◽  
Time Course ◽  
Early Time ◽  
Stimulus Onset ◽  
Feature Model ◽  
Numerical Magnitude ◽  
Numerical Comparison ◽  
Number Representation ◽  
Number Representations ◽  
Symbolic Number

AbstractThe human brain can rapidly form representations of numerical magnitude, whether presented with symbolic stimuli like digits and words or non-symbolic stimuli like dot displays. Little is known about the relative time course of these symbolic and non-symbolic number representations. We investigated the emergence of number representations for three stimulus formats - digits, words, and dot arrays - by applying multivariate pattern analysis to MEG recordings from 22 participants. We first conducted within-format classification to identify the time course by which individual numbers can be decoded from the MEG signal. Peak classification accuracy for individual numbers in all three formats occurred around 110 ms after stimulus onset. Next, we used between-format classification to determine the time course of shared number representations between stimulus formats. Classification accuracy between formats was much weaker than within format classification, but it was also significant at early time points, around 100 ms for both digit / dot and digit / word comparisons. We then used representational similarity analysis to determine if we could explain variance in the MEG representational geometry using two models: a GIST feature model capturing low-level visual properties and an approximate number model capturing the numerical magnitude of the stimuli. Model RSA results differed between stimulus formats: while the GIST model explained unique variance from 100-300 ms for all number formats, the performance of the approximate number model differed between formats. Together, these results are consistent with the view that distinct, format-specific number representations, moreso than a single “abstract” number representation, form the basis of numerical comparison.

Basic Number Representation and Beyond

2015 ◽  
Author(s):  
Chantal Roggeman ◽  
Wim Fias ◽  
Tom Verguts
Keyword(s):  
Decision Making ◽  
Working Memory ◽  
Real Life ◽  
Network Models ◽  
Basic Number ◽  
Number Processing ◽  
Number Representation ◽  
Number Representations ◽  
Symbolic Number ◽  
Related Theme

We discuss recent computational network models of elementary number processing. One key issue to emerge from this work is a crucial distinction between symbolic and non-symbolic number representation, and the related distinction between number-selective and number-sensitive coding. Empirical predictions from the models were tested, and are here summarized. Another issue is the relation with task-based decision making mechanisms. In both lab and real-life settings, representations are seldomly accessed in a task-neutral manner, rather subjects are usually presented with a task. A related theme is the functional association between number representations and working memory. In these issues also, both modeling and neuroimaging work is summarized. To conclude, we propose that the combined modeling-neuroimaging approach should be extended to tackle more complex questions about number processing (e.g. fractions, development, dyscalculia).

scholarly journals Narrowing the early mathematics gap: A play-based intervention to promote low-income preschoolers’ number skills

2018 ◽  
Vol 3 (3) ◽  
pp. 559-581 ◽  
Author(s):  
Nicole R. Scalise ◽  
Emily N. Daubert ◽  
Geetha B. Ramani
Keyword(s):  
Low Income ◽  
Numerical Magnitude ◽  
Card Game ◽  
Middle Income ◽  
Early Mathematics ◽  
Magnitude Comparison ◽  
Number Representations ◽  
And Gender ◽  
Symbolic Number ◽  
Numerical Knowledge

Preschoolers from low-income households lag behind preschoolers from middle-income households on numerical skills that underlie later mathematics achievement. However, it is unknown whether these gaps exist on parallel measures of symbolic and non-symbolic numerical skills. Experiment 1 indicated preschoolers from low-income backgrounds were less accurate than peers from middle-income backgrounds on a measure of symbolic magnitude comparison, but they performed equivalently on a measure of non-symbolic magnitude comparison. This suggests activities linking non-symbolic and symbolic number representations may be used to support children’s numerical knowledge. Experiment 2 randomly assigned low-income preschoolers (Mean Age = 4.7 years) to play either a numerical magnitude comparison or a numerical matching card game across four 15 min sessions over a 3-week period. The magnitude comparison card game led to significant improvements in participants’ symbolic magnitude comparison skills in an immediate posttest assessment. Following the intervention, low-income participants performed equivalently to an age- and gender-matched sample of middle-income preschoolers in symbolic magnitude comparison. These results suggest a brief intervention that combines non-symbolic and symbolic magnitude representations can support low-income preschoolers’ early numerical knowledge.

Neural Underpinnings of Numerical and Spatial Cognition: An fMRI Meta-Analysis of Brain Regions Associated with Symbolic Number, Arithmetic, and Mental Rotation

2019 ◽  
Author(s):  
Zachary Hawes ◽  
H Moriah Sokolowski ◽  
Chuka Bosah Ononye ◽  
Daniel Ansari
Keyword(s):  
Mental Rotation ◽  
Parietal Lobe ◽  
Meta Analysis ◽  
Likelihood Estimation ◽  
Brain Regions ◽  
Angular Gyrus ◽  
Number Representation ◽  
Neural Underpinnings ◽  
The Right ◽  
Symbolic Number

Where and under what conditions do spatial and numerical skills converge and diverge in the brain? To address this question, we conducted a meta-analysis of brain regions associated with basic symbolic number processing, arithmetic, and mental rotation. We used Activation Likelihood Estimation (ALE) to construct quantitative meta-analytic maps synthesizing results from 86 neuroimaging papers (~ 30 studies/cognitive process). All three cognitive processes were found to activate bilateral parietal regions in and around the intraparietal sulcus (IPS); a finding consistent with shared processing accounts. Numerical and arithmetic processing were associated with overlap in the left angular gyrus, whereas mental rotation and arithmetic both showed activity in the middle frontal gyri. These patterns suggest regions of cortex potentially more specialized for symbolic number representation and domain-general mental manipulation, respectively. Additionally, arithmetic was associated with unique activity throughout the fronto-parietal network and mental rotation was associated with unique activity in the right superior parietal lobe. Overall, these results provide new insights into the intersection of numerical and spatial thought in the human brain.

scholarly journals The Rapid Extraction of Gist—Early Neural Correlates of High-level Visual Processing

2012 ◽  
Vol 24 (2) ◽  
pp. 521-529 ◽  
Author(s):  
Frank Oppermann ◽  
Uwe Hassler ◽  
Jörg D. Jescheniak ◽  
Thomas Gruber
Keyword(s):  
Visual Processing ◽  
Time Course ◽  
Occipital Cortex ◽  
Stimulus Onset ◽  
Gamma Band ◽  
Oscillatory Activity ◽  
Rapid Extraction ◽  
The Right ◽  
High Level ◽  
Individual Objects

The human cognitive system is highly efficient in extracting information from our visual environment. This efficiency is based on acquired knowledge that guides our attention toward relevant events and promotes the recognition of individual objects as they appear in visual scenes. The experience-based representation of such knowledge contains not only information about the individual objects but also about relations between them, such as the typical context in which individual objects co-occur. The present EEG study aimed at exploring the availability of such relational knowledge in the time course of visual scene processing, using oscillatory evoked gamma-band responses as a neural correlate for a currently activated cortical stimulus representation. Participants decided whether two simultaneously presented objects were conceptually coherent (e.g., mouse–cheese) or not (e.g., crown–mushroom). We obtained increased evoked gamma-band responses for coherent scenes compared with incoherent scenes beginning as early as 70 msec after stimulus onset within a distributed cortical network, including the right temporal, the right frontal, and the bilateral occipital cortex. This finding provides empirical evidence for the functional importance of evoked oscillatory activity in high-level vision beyond the visual cortex and, thus, gives new insights into the functional relevance of neuronal interactions. It also indicates the very early availability of experience-based knowledge that might be regarded as a fundamental mechanism for the rapid extraction of the gist of a scene.

Perception and first defense responses against Pseudomonas syringae pv. phaseolicola in Phaseolus vulgaris L.: identification of Wall-Associated Kinase receptors

2021 ◽  
Author(s):  
Alfonso Gonzalo De la Rubia ◽  
María Luz Centeno ◽  
Victor Moreno-González ◽  
María De Castro ◽  
Penélope García-Angulo
Keyword(s):  
Phaseolus Vulgaris ◽  
Pseudomonas Syringae ◽  
Time Course ◽  
Early Time ◽  
Experimental System ◽  
Antioxidant Response ◽  
Defense Responses ◽  
Cellular Damage ◽  
Initial Increase ◽  
Phaseolus Vulgaris L

Common bean (Phaseolus vulgaris L.) is attacked by several pathogens such as the biotrophic gamma-proteobacterium Pseudomonas syringae pv. phaseolicola (Pph). In order to study the Pph-bean interaction during the first stages of infection, leaf disks of a susceptible bean variety named Riñón were infected with a pathogenic Pph. Using this experimental system, six new putative Wall-Associated Kinase (WAKs) receptors, previously identified in silico, were tested. These six bean WAKs (PvWAKs) showed high protein sequence homology to the well-described Arabidopsis WAK1 (AtWAK1) receptor and, by phylogenetic analysis, clustered together with AtWAKs. The expression of PvWAK1 increased at very early stages after the Pph infection. Time course experiments were performed to evaluate the accumulation of apoplastic H2O2, Ca2+ influx, total H2O2, antioxidant enzymatic activities, lipid peroxidation, and the concentrations of abscisic acid (ABA) and salicylic acid (SA), as well as the expression of six defense-related genes – MEKK-1, MAPKK, WRKY33, RIN4, PR1 and NPR1. The results showed that overexpression of PR1 occurred 2 h after Pph infection without a concomitant increase in SA levels. Although apoplastic H2O2 increased after infection, the oxidative burst was neither intense nor rapid and an efficient antioxidant response did not occur, suggesting that the observed cellular damage was due to the initial increase in total H2O2 at early time points after infection. In conclusion, the Riñón variety can perceive the presence of Pph, but this recognition only results in a modest and slow activation of host defenses, leading to high susceptibility to Pph.

Temporal Dynamics of Shape Analysis in Macaque Visual Area V2

2004 ◽  
Vol 92 (5) ◽  
pp. 3030-3042 ◽  
Author(s):  
Jay Hegdé ◽  
David C. Van Essen
Keyword(s):  
Cortical Neurons ◽  
Time Course ◽  
Temporal Dynamics ◽  
Visual Stimulation ◽  
Signal To Noise Ratio ◽  
Stimulus Onset ◽  
Visual Area ◽  
Response Modulation ◽  
Population Response ◽  
Area V2

The firing rate of visual cortical neurons typically changes substantially during a sustained visual stimulus. To assess whether, and to what extent, the information about shape conveyed by neurons in visual area V2 changes over the course of the response, we recorded the responses of V2 neurons in awake, fixating monkeys while presenting a diverse set of static shape stimuli within the classical receptive field. We analyzed the time course of various measures of responsiveness and stimulus-related response modulation at the level of individual cells and of the population. For a majority of V2 cells, the response modulation was maximal during the initial transient response (40–80 ms after stimulus onset). During the same period, the population response was relatively correlated, in that V2 cells tended to respond similarly to specific subsets of stimuli. Over the ensuing 80–100 ms, the signal-to-noise ratio of individual cells generally declined, but to a lesser degree than the evoked-response rate during the corresponding time bins, and the response profiles became decorrelated for many individual cells. Concomitantly, the population response became substantially decorrelated. Our results indicate that the information about stimulus shape evolves dynamically and relatively rapidly in V2 during static visual stimulation in ways that may contribute to form discrimination.

Early time course of myocardial electrical impedance during acute coronary artery occlusion in pigs, dogs, and humans

2005 ◽  
Vol 99 (4) ◽  
pp. 1576-1581 ◽  
Author(s):  
Carlos L. del Rio ◽  
Patrick I. McConnell ◽  
Bradley D. Clymer ◽  
Roger Dzwonczyk ◽  
Robert E. Michler ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Time Course ◽  
Electrical Impedance ◽  
Early Time ◽  
Coronary Artery Occlusion ◽  
Artery Occlusion ◽  
Acute Ischemia ◽  
Collateral Flow ◽  
Total Occlusion ◽  
Interspecies Differences

Changes in myocardial electrical impedance (MEI) and physiological end points have been correlated during acute ischemia. However, the importance of MEI's early time course is not clear. This study evaluates such significance, by comparing the temporal behavior of MEI during acute total occlusion of the left anterior descending coronary artery in anesthetized humans, dogs, and pigs. Here, interspecies differences in three MEI parameters (baseline, time to plateau onset, and plateau value normalized by baseline) were evaluated using Kruskal-Wallis ANOVA and post hoc tests ( P < 0.05). Noteworthy differences in the MEI time to plateau onset were observed: In dogs, MEI ischemic plateau was reached after 46.3 min (SD 12.9) min of occlusion, a significantly longer period compared with that of pigs and humans [4.7 (SD 1.2) and 4.1 min (SD 1.9), respectively]. However, no differences could be observed between both animal species regarding the normalized MEI ischemic plateau value (15.3% (SD 4.7) in pigs, vs. 19.6% (SD 2.6) in dogs). For all studied MEI parameters, only swine values resembled those of humans. The severity of myocardial supply ischemia, resulting from coronary artery occlusion, is known to be dependent on collateral flow. Thus, because dogs possess a well-developed collateral system (unlike humans or pigs), they have shown superior resistance to occlusion of a coronary artery. Here, the early MEI time course after left anterior descending coronary artery occlusion, represented by the time required to reach ischemic plateau, was proven to reflect such interspecies differences.

Intentional attention switching in dichotic listening: Exploring the efficiency of nonspatial and spatial selection

2014 ◽  
Vol 67 (10) ◽  
pp. 2010-2024 ◽  
Author(s):  
Vera Lawo ◽  
Janina Fels ◽  
Josefa Oberem ◽  
Iring Koch
Keyword(s):  
Dichotic Listening ◽  
Target Selection ◽  
Stimulus Onset ◽  
Numerical Magnitude ◽  
Relevant Feature ◽  
Attention Switching ◽  
Number Words ◽  
Switch Costs ◽  
Feature Dimension ◽  
Listening Task

Using an auditory variant of task switching, we examined the ability to intentionally switch attention in a dichotic-listening task. In our study, participants responded selectively to one of two simultaneously presented auditory number words (spoken by a female and a male, one for each ear) by categorizing its numerical magnitude. The mapping of gender (female vs. male) and ear (left vs. right) was unpredictable. The to-be-attended feature for gender or ear, respectively, was indicated by a visual selection cue prior to auditory stimulus onset. In Experiment 1, explicitly cued switches of the relevant feature dimension (e.g., from gender to ear) and switches of the relevant feature within a dimension (e.g., from male to female) occurred in an unpredictable manner. We found large performance costs when the relevant feature switched, but switches of the relevant feature dimension incurred only small additional costs. The feature-switch costs were larger in ear-relevant than in gender-relevant trials. In Experiment 2, we replicated these findings using a simplified design (i.e., only within-dimension switches with blocked dimensions). In Experiment 3, we examined preparation effects by manipulating the cueing interval and found a preparation benefit only when ear was cued. Together, our data suggest that the large part of attentional switch costs arises from reconfiguration at the level of relevant auditory features (e.g., left vs. right) rather than feature dimensions (ear vs. gender). Additionally, our findings suggest that ear-based target selection benefits more from preparation time (i.e., time to direct attention to one ear) than gender-based target selection.

scholarly journals Reversing the Manual Digit Bias in Two-Digit Number Comparison

2017 ◽  
Vol 64 (3) ◽  
pp. 191-204 ◽  
Author(s):  
Thomas J. Faulkenberry ◽  
Alexander Cruise ◽  
Samuel Shaki
Keyword(s):  
Numerical Cognition ◽  
Number Line ◽  
Number Representation ◽  
Digit Number ◽  
Computer Mouse ◽  
Number Comparison ◽  
Number Representations ◽  
Mouse Movements ◽  
Embodied Representation ◽  
Fixed Standard

Abstract. Though recent work in numerical cognition has supported a strong tie between numerical and spatial representations (e.g., a mental number line), less is known about such ties in multi-digit number representations. Along this line, Bloechle, Huber, and Moeller (2015) found that pointing positions in two-digit number comparison were biased leftward toward the decade digit. Moreover, this bias was reduced in unit-decade incompatible pairs. In the present study, we tracked computer mouse movements as participants compared two-digit numbers to a fixed standard (55). Similar to Bloechle et al. (2015) , we found that trajectories exhibited a leftward bias that was reduced for unit-decade incompatible comparisons. However, when positions of response labels were reversed, the biases reversed. That is, we found a rightward bias for compatible pairs that was reduced for incompatible pairs. This result calls into question a purely embodied representation of place value structure and instead supports a competition model of two-digit number representation.

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