scholarly journals RUBubbles as a novel tool to study categorization learning

2021 ◽  
Author(s):  
Aylin Apostel ◽  
Jonas Rose
Keyword(s):  
Large Stimulus ◽  
Computational Costs ◽  
Stimulus Response ◽  
Matlab Code ◽  
3D Space ◽  
Widespread Phenomenon ◽  
Stimulus Features ◽  
Abstraction Levels ◽  
Different Characteristics ◽  
High Degree

AbstractGrouping objects into discrete categories affects how we perceive the world and represents a crucial element of cognition. Categorization is a widespread phenomenon that has been thoroughly studied. However, investigating categorization learning poses several requirements on the stimulus set in order to control which stimulus feature is used and to prevent mere stimulus–response associations or rote learning. Previous studies have used a wide variety of both naturalistic and artificial categories, the latter having several advantages such as better control and more direct manipulation of stimulus features. We developed a novel stimulus type to study categorization learning, which allows a high degree of customization at low computational costs and can thus be used to generate large stimulus sets very quickly. ‘RUBubbles’ are designed as visual artificial category stimuli that consist of an arbitrary number of colored spheres arranged in 3D space. They are generated using custom MATLAB code in which several stimulus parameters can be adjusted and controlled separately, such as number of spheres, position in 3D-space, sphere size, and color. Various algorithms for RUBubble generation can be combined with distinct behavioral training protocols to investigate different characteristics and strategies of categorization learning, such as prototype- vs. exemplar-based learning, different abstraction levels, or the categorization of a sensory continuum and category exceptions. All necessary MATLAB code is freely available as open-source code and can be customized or expanded depending on individual needs. RUBubble stimuli can be controlled purely programmatically or via a graphical user interface without MATLAB license or programming experience. Graphical abstract

scholarly journals Cognitive control in bilinguals: Advantages in Stimulus–Stimulus inhibition

2013 ◽  
Vol 17 (3) ◽  
pp. 610-629 ◽  
Author(s):  
HENRIKE K. BLUMENFELD ◽  
VIORICA MARIAN
Keyword(s):  
Cognitive Control ◽  
Language Processing ◽  
Stroop Task ◽  
Simon Task ◽  
Irrelevant Information ◽  
Control Mechanisms ◽  
Stimulus Response ◽  
Stimulus Features ◽  
Task Irrelevant ◽  
Language Profiles

Bilinguals have been shown to outperform monolinguals at suppressing task-irrelevant information and on overall speed during cognitive control tasks. Here, monolinguals’ and bilinguals’ performance was compared on two nonlinguistic tasks: a Stroop task (with perceptualStimulus–Stimulus conflictamong stimulus features) and a Simon task (withStimulus–Response conflict). Across two experiments testing bilinguals with different language profiles, bilinguals showed more efficient Stroop than Simon performance, relative to monolinguals, who showed fewer differences across the two tasks. Findings suggest that bilingualism may engage Stroop-type cognitive control mechanisms more than Simon-type mechanisms, likely due to increased Stimulus–Stimulus conflict during bilingual language processing. Findings are discussed in light of previous research on bilingual Stroop and Simon performance.

scholarly journals Effects of stimulus features and instruction on response coding, selection, and inhibition: Evidence from repetition effects under task switching

2008 ◽  
Vol 61 (10) ◽  
pp. 1573-1600 ◽  
Author(s):  
Michel D. Druey ◽  
Ronald Hübner
Keyword(s):  
Task Switching ◽  
Response Selection ◽  
Middle Finger ◽  
Task Switch ◽  
Negative Effects ◽  
Repetition Effects ◽  
Stimulus Response ◽  
Stimulus Features ◽  
Feature Overlap ◽  
Response Coding

The coding of stimuli and responses is crucial for human behaviour. Here, we focused primarily on the response codes (or response categories). As a method, we applied a combined dual-task and task-switch paradigm with a fixed task-to-hand mapping. Usually, negative effects (i.e., costs) are observed for response category repetitions under task switching. However, in several previous studies it has been proposed that such repetition effects do not occur, if the stimulus categories (e.g., “odd” if digits have to be classified according to their parity feature) are unequivocally mapped to specific responses. Our aim was to test this hypothesis. In the present experiments, we were able to distinguish between three different types of possible response codes. The results show that the participants generally code their responses according to abstract response features (left/right, or index/middle finger). Moreover, the spatial codes were preferred over the finger-type codes even if the instructions stressed the latter. This preference, though, seemed to result from a stimulus–response feature overlap, so that the spatial response categories were primed by the respective stimulus features. If there was no such overlap, the instructions determined which type of response code was involved in response selection and inhibition.

Auditory Warning Signals Affect Mechanisms of Response Selection

2010 ◽  
Vol 57 (2) ◽  
pp. 89-97 ◽  
Author(s):  
Rico Fischer ◽  
Franziska Plessow ◽  
Andrea Kiesel
Keyword(s):  
Selective Attention ◽  
Response Selection ◽  
Reaction Times ◽  
Relevant Stimulus ◽  
Attention Task ◽  
Stimulus Response ◽  
Spatial Stimulus ◽  
Direct Route ◽  
Stimulus Features ◽  
Indirect Route

Irrelevant tone (accessory) stimuli facilitate performance in simple and choice reaction time tasks. In the present study, we combined accessory stimulation with a selective attention paradigm in order to investigate its influence on mechanisms of response selection. In the framework of a spatial stimulus-response compatibility task (Simon task), we tested whether accessory stimuli selectively affect bottom up triggered response activation processes (e.g., direct route processing), processing of task-relevant stimulus features (indirect route processing), or both/none. Results suggest a two-component effect of accessory stimuli within this selective attention task. First, accessory stimuli increased the Simon effect due to beneficial direct route processing. Second, accessory stimuli generally decreased reaction times indicating facilitation of indirect route processing.

scholarly journals Correlation-based characterisation of time-varying dynamical complexity in the Earth's magnetosphere

2013 ◽  
Vol 20 (6) ◽  
pp. 965-975 ◽  
Author(s):  
R. V. Donner ◽  
G. Balasis
Keyword(s):  
Dynamical Behaviour ◽  
Magnetic Storms ◽  
Time Varying ◽  
Temporal Complexity ◽  
Multi Scale ◽  
Dynamical Complexity ◽  
Geophysical Time Series ◽  
Recorded Data ◽  
Different Characteristics ◽  
High Degree

Abstract. The dynamical behaviour of the magnetosphere is known to be a sensitive indicator for the response of the system to solar wind coupling. Since the solar activity commonly displays very interesting non-stationary and multi-scale dynamics, the magnetospheric response also exhibits a high degree of dynamical complexity associated with fundamentally different characteristics during periods of quiescence and magnetic storms. The resulting temporal complexity profile has been explored using several approaches from applied statistics, dynamical systems theory and statistical mechanics. Here, we propose an alternative way of looking at time-varying dynamical complexity of nonlinear geophysical time series utilising subtle but significant changes in the linear autocorrelation structure of the recorded data. Our approach is demonstrated to sensitively trace the dynamic signatures associated with intense magnetic storms, and to display reasonable skills in distinguishing between quiescence and storm periods. The potentials and methodological limitations of this new viewpoint are discussed in some detail.

scholarly journals Carnivore occurrence: do interview-based surveys produce unreliable results?

Oryx ◽  
2016 ◽  
Vol 51 (2) ◽  
pp. 240-245 ◽  
Author(s):  
N. Caruso ◽  
E. Luengos Vidal ◽  
M. Guerisoli ◽  
M. Lucherini
Keyword(s):  
Puma Concolor ◽  
Cost Effective ◽  
Camera Traps ◽  
Local People ◽  
Wildlife Ecology ◽  
Cost Effective Approach ◽  
Elusive Species ◽  
Different Characteristics ◽  
High Degree

AbstractInterviews with local people have been widely used by biologists as a cost-effective approach to studying certain topics in wildlife ecology and conservation. However, doubts still exist about the validity and quality of the information gathered, especially in studies targeting cryptic or elusive species, such as carnivores. We assessed the reliability of interviews (n = 155) in detecting the presence of three species of carnivores with different characteristics, by comparing interview results with data obtained through camera trapping surveys at 52 sites in central Argentina. The degree of concordance between methods was low for Geoffroy's cat Leopardus geoffroyi and especially for the puma Puma concolor. However, Geoffroy's cats were detected more frequently by camera traps than interviews, whereas the opposite was true for pumas. For the pampas fox Pseudalopex gymnocercus, a less elusive species, we observed a high degree of concordance and a similar probability of occurrence between methods. Our results indicate that data obtained by interviewing local inhabitants should be used with caution because the information about species presence provided by local people may be inaccurate and biased.

scholarly journals DNA Barcoding analysis of seafood accuracy in Washington, D.C. restaurants

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3234 ◽  
Author(s):  
David B. Stern ◽  
Eduardo Castro Nallar ◽  
Jason Rathod ◽  
Keith A. Crandall
Keyword(s):  
Dna Barcoding ◽  
Consumer Protection ◽  
Related Species ◽  
Cost Effective ◽  
The United States ◽  
Reference Sequence ◽  
Closely Related Species ◽  
Widespread Phenomenon ◽  
High Degree ◽  
Fertile Area

In Washington D.C., recent legislation authorizes citizens to test if products are properly represented and, if they are not, to bring a lawsuit for the benefit of the general public. Recent studies revealing the widespread phenomenon of seafood substitution across the United States make it a fertile area for consumer protection testing. DNA barcoding provides an accurate and cost-effective way to perform these tests, especially when tissue alone is available making species identification based on morphology impossible. In this study, we sequenced the 5′ barcoding region of the Cytochrome Oxidase I gene for 12 samples of vertebrate and invertebrate food items across six restaurants in Washington, D.C. and used multiple analytical methods to make identifications. These samples included several ambiguous menu listings, sequences with little genetic variation among closely related species and one sequence with no available reference sequence. Despite these challenges, we were able to make identifications for all samples and found that 33% were potentially mislabeled. While we found a high degree of mislabeling, the errors involved closely related species and we did not identify egregious substitutions as have been found in other cities. This study highlights the efficacy of DNA barcoding and robust analyses in identifying seafood items for consumer protection.

scholarly journals Why sensory neurons are tuned to multiple stimulus features

2020 ◽  
Author(s):  
Matthew V. Macellaio ◽  
Bing Liu ◽  
Jeffrey M. Beck ◽  
Leslie C. Osborne
Keyword(s):  
Sensory Neurons ◽  
Movement Behavior ◽  
Sensory Stimuli ◽  
Stimulus Response ◽  
Pursuit Eye Movements ◽  
Multiple Stimulus ◽  
Computational Advantage ◽  
Information Advantage ◽  
Stimulus Features ◽  
The Brain

Many sensory neurons encode information about more than one stimulus feature. Multidimensional tuning increases ambiguity in stimulus-response relationships, but we find that it also offers an unexpected computational advantage, allowing the brain to better reconstruct sensory stimuli. From the responses of sensory neurons, populations, and sensory-driven movement behavior, more information can be recovered about a stimulus vector than about its individual components. We term this coding advantage “stimulus synergy” and show that it is distinct from other coding synergies, arising from inseparability of the response-conditioned stimulus distribution along individual stimulus dimensions. From extracellular recordings in motion sensitive cortex and measurements of pursuit eye movements, we demonstrate that stimulus synergy in cortical populations is preserved downstream in the precision of pursuit, and that a common decoding model predicts the level of synergy in pursuit behavior. This suggests that the brain exploits the information advantage afforded by multidimensional sensory tuning.

scholarly journals Generalized and Multiple-Queries-Oriented Privacy Budget Strategies in Differential Privacy via Convergent Series

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Yunlu Bai ◽  
Geng Yang ◽  
Yang Xiang ◽  
Xuan Wang
Keyword(s):  
High Performance ◽  
Differential Privacy ◽  
Budget Allocation ◽  
Convergent Series ◽  
Multiple Queries ◽  
Analysis Task ◽  
Different Characteristics ◽  
High Degree ◽  
Privacy Budget ◽  
Allocation Strategies

For data analysis with differential privacy, an analysis task usually requires multiple queries to complete, and the total budget needs to be divided into different parts and allocated to each query. However, at present, the budget allocation in differential privacy lacks efficient and general allocation strategies, and most of the research tends to adopt an average or exclusive allocation method. In this paper, we propose two series strategies for budget allocation: the geometric series and the Taylor series. We show the different characteristics of the two series and provide a calculation method for selecting the key parameters. To better reflect a user’s preference of noise during the allocation, we explored the relationship between sensitivity and noise in detail, and, based on this, we propose an optimization for the series strategies. Finally, to prevent collusion attacks and improve security, we provide three ideas for protecting the budget sequence. Both the theoretical analysis and experimental results show that our methods can support more queries and achieve higher utility. This shows that our series allocation strategies have a high degree of flexibility which can meet the user’s need and allow them to be better applied to differentially private algorithms to achieve high performance while maintaining the security.

scholarly journals Temporal expectancy modulates stimulus–response integration

2021 ◽  
Author(s):  
Philip Schmalbrock ◽  
Christian Frings
Keyword(s):  
Response Speed ◽  
Action Control ◽  
Time Interval ◽  
Action Perception ◽  
Event File ◽  
Temporal Expectancy ◽  
Stimulus Response ◽  
Foreperiod Duration ◽  
The Difference ◽  
Stimulus Features

AbstractWe can use information derived from passing time to anticipate an upcoming event. If time before an event varies, responses towards this event become faster with increasing waiting time. This variable-foreperiod effect has been often observed in response-speed studies. Different action control frameworks assume that response and stimulus features are integrated into an event file that is retrieved later if features repeat. Yet the role of foreperiods has so far not been investigated in action control. Thus, we investigated the influence of foreperiod on the integration of action-perception features. Participants worked through a standard distractor–response binding paradigm where two consecutive responses are made towards target letters while distractor letters are present. Responses and/or distractors can repeat or change from first to second display, leading to partial repetition costs when only some features repeat or repetition benefits when all features repeat (the difference constituting distractor–response binding). To investigate the effect of foreperiod, we also introduced an anti-geometric distribution of foreperiods to the time interval before the first response display. We observed that distractor–response binding increased with increasing foreperiod duration, and speculate that this was driven by an increase in motor readiness induced by temporal expectancy.

Hierarchical Task Representation

2016 ◽  
Vol 25 (6) ◽  
pp. 449-454 ◽  
Author(s):  
Eric H. Schumacher ◽  
Eliot Hazeltine
Keyword(s):  
Human Behavior ◽  
Experimental Research ◽  
Response Selection ◽  
Action Selection ◽  
Task Representation ◽  
Alternative Framework ◽  
Stimulus Response ◽  
Discrete Responses ◽  
Multiple Levels ◽  
Stimulus Features

Human behavior is remarkably complex—even during the performance of relatively simple tasks—yet it is often assumed that learned associations between stimuli and responses provide the representational substrate for action selection. Here, we introduce an alternative framework, called a task file, that includes hierarchical associations between stimulus features, response features, goals, and drives, which may overcome the limitations inherent in the conceptualization of response selection as being based solely on associations between stimuli and responses. We then review evidence from our own experimental research showing that even in the context of performing relatively easy tasks, the stimulus-response-association approach to response selection is inadequate to account for the interactions between discrete responses. Instead, response selection may emerge from competition between linked representations at multiple levels.

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