TY - JOUR
A1 - Mertzen, Daniela
A1 - Lago, Sol
A1 - Vasishth, Shravan
T1 - The benefits of preregistration for hypothesis-driven bilingualism research
JF - Bilingualism : language and cognition
N2 - Preregistration is an open science practice that requires the specification of research hypotheses and analysis plans before the data are inspected. Here, we discuss the benefits of preregistration for hypothesis-driven, confirmatory bilingualism research. Using examples from psycholinguistics and bilingualism, we illustrate how non-peer reviewed preregistrations can serve to implement a clean distinction between hypothesis testing and data exploration. This distinction helps researchers avoid casting post-hoc hypotheses and analyses as confirmatory ones. We argue that, in keeping with current best practices in the experimental sciences, preregistration, along with sharing data and code, should be an integral part of hypothesis-driven bilingualism research.
KW - preregistration
KW - open science
KW - bilingualism
KW - psycholinguistics
KW - confirmatory analysis
KW - exploratory analysis
Y1 - 2021
U6 - https://doi.org/10.1017/S1366728921000031
SN - 1366-7289
SN - 1469-1841
VL - 24
IS - 5
SP - 807
EP - 812
PB - Cambridge Univ. Press
CY - Cambridge
ER -
TY - JOUR
A1 - Jäger, Lena Ann
A1 - Mertzen, Daniela
A1 - Van Dyke, Julie A.
A1 - Vasishth, Shravan
T1 - Interference patterns in subject-verb agreement and reflexives revisited
BT - a large-sample study
JF - Journal of memory and language
N2 - Cue-based retrieval theories in sentence processing predict two classes of interference effect: (i) Inhibitory interference is predicted when multiple items match a retrieval cue: cue-overloading leads to an overall slowdown in reading time; and (ii) Facilitatory interference arises when a retrieval target as well as a distractor only partially match the retrieval cues; this partial matching leads to an overall speedup in retrieval time. Inhibitory interference effects are widely observed, but facilitatory interference apparently has an exception: reflexives have been claimed to show no facilitatory interference effects. Because the claim is based on underpowered studies, we conducted a large-sample experiment that investigated both facilitatory and inhibitory interference. In contrast to previous studies, we find facilitatory interference effects in reflexives. We also present a quantitative evaluation of the cue-based retrieval model of Engelmann, Jager, and Vasishth (2019).
KW - Sentence processing
KW - Cue-based retrieval
KW - Similarity-based interference
KW - Reflexives
KW - Agreement
KW - Bayesian data analysis
KW - Replication
Y1 - 2020
U6 - https://doi.org/10.1016/j.jml.2019.104063
SN - 0749-596X
SN - 1096-0821
VL - 111
PB - Elsevier
CY - San Diego
ER -
TY - JOUR
A1 - Avetisyan, Serine
A1 - Lago, Sol
A1 - Vasishth, Shravan
T1 - Does case marking affect agreement attraction in comprehension?
JF - Journal of memory and language
N2 - Previous studies have suggested that distinctive case marking on noun phrases reduces attraction effects in production, i.e., the tendency to produce a verb that agrees with a nonsubject noun. An important open question is whether attraction effects are modulated by case information in sentence comprehension. To address this question, we conducted three attraction experiments in Armenian, a language with a rich and productive case system. The experiments showed clear attraction effects, and they also revealed an overall role of case marking such that participants showed faster response and reading times when the nouns in the sentence had different case. However, we found little indication that distinctive case marking modulated attraction effects. We present a theoretical proposal of how case and number information may be used differentially during agreement licensing in comprehension. More generally, this work sheds light on the nature of the retrieval cues deployed when completing morphosyntactic dependencies.
KW - subject-verb agreement
KW - attraction
KW - Case
KW - Eastern Armenian
KW - cue-based
KW - retrieval
KW - comprehension
Y1 - 2020
U6 - https://doi.org/10.1016/j.jml.2020.104087
SN - 0749-596X
SN - 1096-0821
VL - 112
PB - Elsevier
CY - San Diego
ER -
TY - GEN
A1 - Stone, Kate
A1 - Nicenboim, Bruno
A1 - Vasishth, Shravan
A1 - Rösler, Frank
T1 - Understanding the effects of constraint and predictability in ERP
T2 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe
N2 - Intuitively, strongly constraining contexts should lead to stronger probabilistic representations of sentences in memory. Encountering unexpected words could therefore be expected to trigger costlier shifts in these representations than expected words. However, psycholinguistic measures commonly used to study probabilistic processing, such as the N400 event-related potential (ERP) component, are sensitive to word predictability but not to contextual constraint. Some research suggests that constraint-related processing cost may be measurable via an ERP positivity following the N400, known as the anterior post-N400 positivity (PNP). The PNP is argued to reflect update of a sentence representation and to be distinct from the posterior P600, which reflects conflict detection and reanalysis. However, constraint-related PNP findings are inconsistent. We sought to conceptually replicate Federmeier et al. (2007) and Kuperberg et al. (2020), who observed that the PNP, but not the N400 or the P600, was affected by constraint at unexpected but plausible words. Using a pre-registered design and statistical approach maximising power, we demonstrated a dissociated effect of predictability and constraint: strong evidence for predictability but not constraint in the N400 window, and strong evidence for constraint but not predictability in the later window. However, the constraint effect was consistent with a P600 and not a PNP, suggesting increased conflict between a strong representation and unexpected input rather than greater update of the representation. We conclude that either a simple strong/weak constraint design is not always sufficient to elicit the PNP, or that previous PNP constraint findings could be an artifact of smaller sample size.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 829
KW - N400
KW - anterior PNP
KW - posterior P600
KW - probabilistic processing
KW - constraint
KW - predictability
KW - entropy
Y1 - 2023
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-587594
SN - 1866-8364
IS - 829
ER -
TY - JOUR
A1 - Stone, Kate
A1 - Nicenboim, Bruno
A1 - Vasishth, Shravan
A1 - Rösler, Frank
T1 - Understanding the effects of constraint and predictability in ERP
JF - Neurobiology of language
N2 - Intuitively, strongly constraining contexts should lead to stronger probabilistic representations of sentences in memory. Encountering unexpected words could therefore be expected to trigger costlier shifts in these representations than expected words. However, psycholinguistic measures commonly used to study probabilistic processing, such as the N400 event-related potential (ERP) component, are sensitive to word predictability but not to contextual constraint. Some research suggests that constraint-related processing cost may be measurable via an ERP positivity following the N400, known as the anterior post-N400 positivity (PNP). The PNP is argued to reflect update of a sentence representation and to be distinct from the posterior P600, which reflects conflict detection and reanalysis. However, constraint-related PNP findings are inconsistent. We sought to conceptually replicate Federmeier et al. (2007) and Kuperberg et al. (2020), who observed that the PNP, but not the N400 or the P600, was affected by constraint at unexpected but plausible words. Using a pre-registered design and statistical approach maximising power, we demonstrated a dissociated effect of predictability and constraint: strong evidence for predictability but not constraint in the N400 window, and strong evidence for constraint but not predictability in the later window. However, the constraint effect was consistent with a P600 and not a PNP, suggesting increased conflict between a strong representation and unexpected input rather than greater update of the representation. We conclude that either a simple strong/weak constraint design is not always sufficient to elicit the PNP, or that previous PNP constraint findings could be an artifact of smaller sample size.
KW - N400
KW - anterior PNP
KW - posterior P600
KW - probabilistic processing
KW - constraint
KW - predictability
KW - entropy
Y1 - 2022
U6 - https://doi.org/10.1162/nol_a_00094
SN - 2641-4368
VL - 4
IS - 2
SP - 221
EP - 256
PB - MIT Press
CY - Cambridge, MA, USA
ER -
TY - JOUR
A1 - Paape, Dario
A1 - Vasishth, Shravan
A1 - von der Malsburg, Titus Raban
T1 - Quadruplex negatio invertit?
BT - the on-line processing of depth charge sentences
JF - Journal of semantics
N2 - So-called "depth charge" sentences (No head injury is too trivial to be ignored) are interpreted by the vast majority of speakers to mean the opposite of what their compositional semantics would dictate. The semantic inversion that is observed for sentences of this type is the strongest and most persistent linguistic illusion known to the field (Wason & Reich, 1979). However, it has recently been argued that the preferred interpretation arises not because of a prevailing failure of the processing system, but rather because the non-compositional meaning is grammaticalized in the form of a stored construction (Cook & Stevenson, 2010; Fortuin, 2014). In a series of five experiments, we investigate whether the depth charge effect is better explained by processing failure due to memory overload (the overloading hypothesis) or by the existence of an underlying grammaticalized construction with two available meanings (the ambiguity hypothesis). To our knowledge, our experiments are the first to explore the on-line processing profile of depth charge sentences. Overall, the data are consistent with specific variants of the ambiguity and overloading hypotheses while providing evidence against other variants. As an extension of the overloading hypothesis, we suggest two heuristic processes that may ultimately yield the incorrect reading when compositional processing is suspended for strategic reasons.
Y1 - 2020
U6 - https://doi.org/10.1093/jos/ffaa009
SN - 0167-5133
SN - 1477-4593
VL - 37
IS - 4
SP - 509
EP - 555
PB - Oxford Univ. Press
CY - Oxford
ER -
TY - JOUR
A1 - Stone, Kate
A1 - von der Malsburg, Titus Raban
A1 - Vasishth, Shravan
T1 - The effect of decay and lexical uncertainty on processing long-distance dependencies in reading
JF - PeerJ
N2 - To make sense of a sentence, a reader must keep track of dependent relationships between words, such as between a verb and its particle (e.g. turn the music down). In languages such as German, verb-particle dependencies often span long distances, with the particle only appearing at the end of the clause. This means that it may be necessary to process a large amount of intervening sentence material before the full verb of the sentence is known. To facilitate processing, previous studies have shown that readers can preactivate the lexical information of neighbouring upcoming words, but less is known about whether such preactivation can be sustained over longer distances. We asked the question, do readers preactivate lexical information about long-distance verb particles? In one self-paced reading and one eye tracking experiment, we delayed the appearance of an obligatory verb particle that varied only in the predictability of its lexical identity. We additionally manipulated the length of the delay in order to test two contrasting accounts of dependency processing: that increased distance between dependent elements may sharpen expectation of the distant word and facilitate its processing (an antilocality effect), or that it may slow processing via temporal activation decay (a locality effect). We isolated decay by delaying the particle with a neutral noun modifier containing no information about the identity of the upcoming particle, and no known sources of interference or working memory load. Under the assumption that readers would preactivate the lexical representations of plausible verb particles, we hypothesised that a smaller number of plausible particles would lead to stronger preactivation of each particle, and thus higher predictability of the target. This in turn should have made predictable target particles more resistant to the effects of decay than less predictable target particles. The eye tracking experiment provided evidence that higher predictability did facilitate reading times, but found evidence against any effect of decay or its interaction with predictability. The self-paced reading study provided evidence against any effect of predictability or temporal decay, or their interaction. In sum, we provide evidence from eye movements that readers preactivate long-distance lexical content and that adding neutral sentence information does not induce detectable decay of this activation. The findings are consistent with accounts suggesting that delaying dependency resolution may only affect processing if the intervening information either confirms expectations or adds to working memory load, and that temporal activation decay alone may not be a major predictor of processing time.
KW - reading
KW - comprehension
KW - temporal decay
KW - preactivation
KW - long distance
KW - dependencies
KW - entropy
KW - psycholinguistics
KW - locality
KW - antilocality
Y1 - 2020
U6 - https://doi.org/10.7717/peerj.10438
SN - 2167-8359
VL - 8
PB - PeerJ Inc.
CY - London
ER -
TY - JOUR
A1 - Vasishth, Shravan
T1 - Using approximate Bayesian computation for estimating parameters in the cue-based retrieval model of sentence processing
JF - MethodsX
N2 - A commonly used approach to parameter estimation in computational models is the so-called grid search procedure: the entire parameter space is searched in small steps to determine the parameter value that provides the best fit to the observed data. This approach has several disadvantages: first, it can be computationally very expensive; second, one optimal point value of the parameter is reported as the best fit value; we cannot quantify our uncertainty about the parameter estimate. In the main journal article that this methods article accompanies (Jager et al., 2020, Interference patterns in subject-verb agreement and reflexives revisited: A large-sample study, Journal of Memory and Language), we carried out parameter estimation using Approximate Bayesian Computation (ABC), which is a Bayesian approach that allows us to quantify our uncertainty about the parameter's values given data. This customization has the further advantage that it allows us to generate both prior and posterior predictive distributions of reading times from the cue-based retrieval model of Lewis and Vasishth, 2005.
Instead of the conventional method of using grid search, we use Approximate Bayesian Computation (ABC) for parameter estimation in the [4] model.
The ABC method of parameter estimation has the advantage that the uncertainty of the parameter can be quantified.
KW - Bayesian parameter estimation
KW - Prior and posterior predictive
KW - distributions
KW - Psycholinguistics
Y1 - 2020
U6 - https://doi.org/10.1016/j.mex.2020.100850
SN - 2215-0161
VL - 7
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Engbert, Ralf
A1 - Rabe, Maximilian Michael
A1 - Schwetlick, Lisa
A1 - Seelig, Stefan A.
A1 - Reich, Sebastian
A1 - Vasishth, Shravan
T1 - Data assimilation in dynamical cognitive science
JF - Trends in cognitive sciences
N2 - Dynamical models make specific assumptions about cognitive processes that generate human behavior. In data assimilation, these models are tested against timeordered data. Recent progress on Bayesian data assimilation demonstrates that this approach combines the strengths of statistical modeling of individual differences with the those of dynamical cognitive models.
Y1 - 2022
U6 - https://doi.org/10.1016/j.tics.2021.11.006
SN - 1364-6613
SN - 1879-307X
VL - 26
IS - 2
SP - 99
EP - 102
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Bürki-Foschini, Audrey Damaris
A1 - Elbuy, Shereen
A1 - Madec, Sylvain
A1 - Vasishth, Shravan
T1 - What did we learn from forty years of research on semantic interference?
BT - a Bayesian meta-analysis
JF - Journal of memory and language
N2 - When participants in an experiment have to name pictures while ignoring distractor words superimposed on the picture or presented auditorily (i.e., picture-word interference paradigm), they take more time when the word to be named (or target) and distractor words are from the same semantic category (e.g., cat-dog). This experimental effect is known as the semantic interference effect, and is probably one of the most studied in the language production literature. The functional origin of the effect and the exact conditions in which it occurs are however still debated. Since Lupker (1979) reported the effect in the first response time experiment about 40 years ago, more than 300 similar experiments have been conducted. The semantic interference effect was replicated in many experiments, but several studies also reported the absence of an effect in a subset of experimental conditions. The aim of the present study is to provide a comprehensive theoretical review of the existing evidence to date and several Bayesian meta-analyses and meta-regressions to determine the size of the effect and explore the experimental conditions in which the effect surfaces. The results are discussed in the light of current debates about the functional origin of the semantic interference effect and its implications for our understanding of the language production system.
KW - Bayesian random effects meta-analysis
KW - picture-word interference
KW - semantic interference
KW - language production
Y1 - 2020
U6 - https://doi.org/10.1016/j.jml.2020.104125
SN - 0749-596X
SN - 1096-0821
VL - 114
PB - Elsevier
CY - San Diego
ER -
TY - JOUR
A1 - Pregla, Dorothea
A1 - Lissón Hernández, Paula J.
A1 - Vasishth, Shravan
A1 - Burchert, Frank
A1 - Stadie, Nicole
T1 - Variability in sentence comprehension in aphasia in German
JF - Brain & language : a journal of the neurobiology of language
N2 - An important aspect of aphasia is the observation of behavioral variability between and within individual participants. Our study addresses variability in sentence comprehension in German, by testing 21 individuals with aphasia and a control group and involving (a) several constructions (declarative sentences, relative clauses and control structures with an overt pronoun or PRO), (b) three response tasks (object manipulation, sentence-picture matching with/without self-paced listening), and (c) two test phases (to investigate test-retest performance). With this systematic, large-scale study we gained insights into variability in sentence comprehension. We found that the size of syntactic effects varied both in aphasia and in control participants. Whereas variability in control participants led to systematic changes, variability in individuals with aphasia was unsystematic across test phases or response tasks. The persistent occurrence of canonicity and interference effects across response tasks and test phases, however, shows that the performance is systematically influenced by syntactic complexity.
KW - Aphasia
KW - Sentence Comprehension
KW - Variability
KW - Test-retest reliability
KW - Task demands
KW - Canonicity and interference effects
KW - Object manipulation
KW - Sentence-picture matching
KW - Self-paced listening
KW - Adaptation
Y1 - 2021
U6 - https://doi.org/10.1016/j.bl.2021.105008
SN - 0093-934X
SN - 1090-2155
VL - 222
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Smith, Garrett
A1 - Vasishth, Shravan
T1 - A principled approach to feature selection in models of sentence processing
JF - Cognitive science : a multidisciplinary journal of anthropology, artificial intelligence, education, linguistics, neuroscience, philosophy, psychology ; journal of the Cognitive Science Society
N2 - Among theories of human language comprehension, cue-based memory retrieval has proven to be a useful framework for understanding when and how processing difficulty arises in the resolution of long-distance dependencies. Most previous work in this area has assumed that very general retrieval cues like [+subject] or [+singular] do the work of identifying (and sometimes misidentifying) a retrieval target in order to establish a dependency between words. However, recent work suggests that general, handpicked retrieval cues like these may not be enough to explain illusions of plausibility (Cunnings & Sturt, 2018), which can arise in sentences like The letter next to the porcelain plate shattered. Capturing such retrieval interference effects requires lexically specific features and retrieval cues, but handpicking the features is hard to do in a principled way and greatly increases modeler degrees of freedom. To remedy this, we use well-established word embedding methods for creating distributed lexical feature representations that encode information relevant for retrieval using distributed retrieval cue vectors. We show that the similarity between the feature and cue vectors (a measure of plausibility) predicts total reading times in Cunnings and Sturt's eye-tracking data. The features can easily be plugged into existing parsing models (including cue-based retrieval and self-organized parsing), putting very different models on more equal footing and facilitating future quantitative comparisons.
KW - Cue‐based retrieval
KW - plausibility
KW - word embeddings
KW - linguistic
KW - features
Y1 - 2020
U6 - https://doi.org/10.1111/cogs.12918
SN - 0364-0213
SN - 1551-6709
VL - 44
IS - 12
PB - Wiley
CY - Hoboken
ER -
TY - JOUR
A1 - Laurinavichyute, Anna
A1 - Yadav, Himanshu
A1 - Vasishth, Shravan
T1 - Share the code, not just the data
BT - a case study of the reproducibility of articles published in the Journal of Memory and Language under the open data policy
JF - Journal of memory and language
N2 - In 2019 the Journal of Memory and Language instituted an open data and code policy; this policy requires that, as a rule, code and data be released at the latest upon publication. How effective is this policy? We compared 59 papers published before, and 59 papers published after, the policy took effect. After the policy was in place, the rate of data sharing increased by more than 50%. We further looked at whether papers published under the open data policy were reproducible, in the sense that the published results should be possible to regenerate given the data, and given the code, when code was provided. For 8 out of the 59 papers, data sets were inaccessible. The reproducibility rate ranged from 34% to 56%, depending on the reproducibility criteria. The strongest predictor of whether an attempt to reproduce would be successful is the presence of the analysis code: it increases the probability of reproducing reported results by almost 40%. We propose two simple steps that can increase the reproducibility of published papers: share the analysis code, and attempt to reproduce one's own analysis using only the shared materials.
KW - Open data
KW - Reproducible statistical analyses
KW - Reproducibility
KW - Open
KW - science
KW - Meta-research
KW - Journal policy
Y1 - 2022
U6 - https://doi.org/10.1016/j.jml.2022.104332
SN - 0749-596X
SN - 1096-0821
VL - 125
PB - Elsevier
CY - San Diego
ER -
TY - GEN
A1 - Stone, Kate
A1 - Vasishth, Shravan
A1 - Malsburg, Titus von der
T1 - Does entropy modulate the prediction of German long-distance verb particles?
T2 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe
N2 - In this paper we examine the effect of uncertainty on readers’ predictions about meaning. In particular, we were interested in how uncertainty might influence the likelihood of committing to a specific sentence meaning. We conducted two event-related potential (ERP) experiments using particle verbs such as turn down and manipulated uncertainty by constraining the context such that readers could be either highly certain about the identity of a distant verb particle, such as turn the bed […] down, or less certain due to competing particles, such as turn the music […] up/down. The study was conducted in German, where verb particles appear clause-finally and may be separated from the verb by a large amount of material. We hypothesised that this separation would encourage readers to predict the particle, and that high certainty would make prediction of a specific particle more likely than lower certainty. If a specific particle was predicted, this would reflect a strong commitment to sentence meaning that should incur a higher processing cost if the prediction is wrong. If a specific particle was less likely to be predicted, commitment should be weaker and the processing cost of a wrong prediction lower. If true, this could suggest that uncertainty discourages predictions via an unacceptable cost-benefit ratio. However, given the clear predictions made by the literature, it was surprisingly unclear whether the uncertainty manipulation affected the two ERP components studied, the N400 and the PNP. Bayes factor analyses showed that evidence for our a priori hypothesised effect sizes was inconclusive, although there was decisive evidence against a priori hypothesised effect sizes larger than 1μV for the N400 and larger than 3μV for the PNP. We attribute the inconclusive finding to the properties of verb-particle dependencies that differ from the verb-noun dependencies in which the N400 and PNP are often studied.
T3 - Zweitveröffentlichungen der Universität Potsdam : Humanwissenschaftliche Reihe - 785
Y1 - 2022
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-562312
SN - 1866-8364
SP - 1
EP - 25
PB - Universitätsverlag Potsdam
CY - Potsdam
ER -
TY - JOUR
A1 - Stone, Kate
A1 - Vasishth, Shravan
A1 - Malsburg, Titus von der
T1 - Does entropy modulate the prediction of German long-distance verb particles?
JF - PLOS ONE
N2 - In this paper we examine the effect of uncertainty on readers’ predictions about meaning. In particular, we were interested in how uncertainty might influence the likelihood of committing to a specific sentence meaning. We conducted two event-related potential (ERP) experiments using particle verbs such as turn down and manipulated uncertainty by constraining the context such that readers could be either highly certain about the identity of a distant verb particle, such as turn the bed […] down, or less certain due to competing particles, such as turn the music […] up/down. The study was conducted in German, where verb particles appear clause-finally and may be separated from the verb by a large amount of material. We hypothesised that this separation would encourage readers to predict the particle, and that high certainty would make prediction of a specific particle more likely than lower certainty. If a specific particle was predicted, this would reflect a strong commitment to sentence meaning that should incur a higher processing cost if the prediction is wrong. If a specific particle was less likely to be predicted, commitment should be weaker and the processing cost of a wrong prediction lower. If true, this could suggest that uncertainty discourages predictions via an unacceptable cost-benefit ratio. However, given the clear predictions made by the literature, it was surprisingly unclear whether the uncertainty manipulation affected the two ERP components studied, the N400 and the PNP. Bayes factor analyses showed that evidence for our a priori hypothesised effect sizes was inconclusive, although there was decisive evidence against a priori hypothesised effect sizes larger than 1μV for the N400 and larger than 3μV for the PNP. We attribute the inconclusive finding to the properties of verb-particle dependencies that differ from the verb-noun dependencies in which the N400 and PNP are often studied.
Y1 - 2022
U6 - https://doi.org/10.1371/journal.pone.0267813
SN - 1932-6203
SP - 1
EP - 25
PB - PLOS ONE
CY - San Francisco, California, US
ER -
TY - JOUR
A1 - Schad, Daniel
A1 - Vasishth, Shravan
A1 - Hohenstein, Sven
A1 - Kliegl, Reinhold
T1 - How to capitalize on a priori contrasts in linear (mixed) models
BT - a tutorial
JF - Journal of memory and language
N2 - Factorial experiments in research on memory, language, and in other areas are often analyzed using analysis of variance (ANOVA). However, for effects with more than one numerator degrees of freedom, e.g., for experimental factors with more than two levels, the ANOVA omnibus F-test is not informative about the source of a main effect or interaction. Because researchers typically have specific hypotheses about which condition means differ from each other, a priori contrasts (i.e., comparisons planned before the sample means are known) between specific conditions or combinations of conditions are the appropriate way to represent such hypotheses in the statistical model. Many researchers have pointed out that contrasts should be "tested instead of, rather than as a supplement to, the ordinary 'omnibus' F test" (Hays, 1973, p. 601). In this tutorial, we explain the mathematics underlying different kinds of contrasts (i.e., treatment, sum, repeated, polynomial, custom, nested, interaction contrasts), discuss their properties, and demonstrate how they are applied in the R System for Statistical Computing (R Core Team, 2018). In this context, we explain the generalized inverse which is needed to compute the coefficients for contrasts that test hypotheses that are not covered by the default set of contrasts. A detailed understanding of contrast coding is crucial for successful and correct specification in linear models (including linear mixed models). Contrasts defined a priori yield far more useful confirmatory tests of experimental hypotheses than standard omnibus F-tests. Reproducible code is available from https://osf.io/7ukf6/.
KW - contrasts
KW - null hypothesis significance testing
KW - linear models
KW - a priori
KW - hypotheses
Y1 - 2019
U6 - https://doi.org/10.1016/j.jml.2019.104038
SN - 0749-596X
SN - 1096-0821
VL - 110
PB - Elsevier
CY - San Diego
ER -
TY - JOUR
A1 - Rabe, Maximilian Michael
A1 - Chandra, Johan
A1 - Krügel, André
A1 - Seelig, Stefan A.
A1 - Vasishth, Shravan
A1 - Engbert, Ralf
T1 - A bayesian approach to dynamical modeling of eye-movement control in reading of normal, mirrored, and scrambled texts
JF - Psychological Review
N2 - In eye-movement control during reading, advanced process-oriented models have been developed to reproduce behavioral data. So far, model complexity and large numbers of model parameters prevented rigorous statistical inference and modeling of interindividual differences. Here we propose a Bayesian approach to both problems for one representative computational model of sentence reading (SWIFT; Engbert et al., Psychological Review, 112, 2005, pp. 777-813). We used experimental data from 36 subjects who read the text in a normal and one of four manipulated text layouts (e.g., mirrored and scrambled letters). The SWIFT model was fitted to subjects and experimental conditions individually to investigate between- subject variability. Based on posterior distributions of model parameters, fixation probabilities and durations are reliably recovered from simulated data and reproduced for withheld empirical data, at both the experimental condition and subject levels. A subsequent statistical analysis of model parameters across reading conditions generates model-driven explanations for observable effects between conditions.
KW - reading eye movements
KW - dynamical models
KW - Bayesian inference
KW - oculomotor
KW - control
KW - individual differences
Y1 - 2021
U6 - https://doi.org/10.1037/rev0000268
SN - 0033-295X
SN - 1939-1471
VL - 128
IS - 5
SP - 803
EP - 823
PB - American Psychological Association
CY - Washington
ER -
TY - JOUR
A1 - Mätzig, Paul
A1 - Vasishth, Shravan
A1 - Engelmann, Felix
A1 - Caplan, David
A1 - Burchert, Frank
T1 - A computational investigation of sources of variability in sentence comprehension difficulty in aphasia
JF - Topics in cognitive science
N2 - We present a computational evaluation of three hypotheses about sources of deficit in sentence comprehension in aphasia: slowed processing, intermittent deficiency, and resource reduction. The ACT-R based Lewis and Vasishth (2005) model is used to implement these three proposals. Slowed processing is implemented as slowed execution time of parse steps; intermittent deficiency as increased random noise in activation of elements in memory; and resource reduction as reduced spreading activation. As data, we considered subject vs. object relative sentences, presented in a self-paced listening modality to 56 individuals with aphasia (IWA) and 46 matched controls. The participants heard the sentences and carried out a picture verification task to decide on an interpretation of the sentence. These response accuracies are used to identify the best parameters (for each participant) that correspond to the three hypotheses mentioned above. We show that controls have more tightly clustered (less variable) parameter values than IWA; specifically, compared to controls, among IWA there are more individuals with slow parsing times, high noise, and low spreading activation. We find that (a) individual IWA show differential amounts of deficit along the three dimensions of slowed processing, intermittent deficiency, and resource reduction, (b) overall, there is evidence for all three sources of deficit playing a role, and (c) IWA have a more variable range of parameter values than controls. An important implication is that it may be meaningless to talk about sources of deficit with respect to an abstract verage IWA; the focus should be on the individual's differential degrees of deficit along different dimensions, and on understanding the causes of variability in deficit between participants.
KW - Sentence comprehension
KW - Aphasia
KW - Computational modeling
KW - Cue-based retrieval
Y1 - 2018
U6 - https://doi.org/10.1111/tops.12323
SN - 1756-8757
SN - 1756-8765
VL - 10
IS - 1
SP - 161
EP - 174
PB - Wiley
CY - Hoboken
ER -
TY - JOUR
A1 - Nicenboim, Bruno
A1 - Vasishth, Shravan
T1 - Models of retrieval in sentence comprehension
BT - a computational evaluation using Bayesian hierarchical modeling
JF - Journal of memory and language
N2 - Research on similarity-based interference has provided extensive evidence that the formation of dependencies between non-adjacent words relies on a cue-based retrieval mechanism. There are two different models that can account for one of the main predictions of interference, i.e., a slowdown at a retrieval site, when several items share a feature associated with a retrieval cue: Lewis and Vasishth’s (2005) activation-based model and McElree’s (2000) direct-access model. Even though these two models have been used almost interchangeably, they are based on different assumptions and predict differences in the relationship between reading times and response accuracy. The activation-based model follows the assumptions of the ACT-R framework, and its retrieval process behaves as a lognormal race between accumulators of evidence with a single variance. Under this model, accuracy of the retrieval is determined by the winner of the race and retrieval time by its rate of accumulation. In contrast, the direct-access model assumes a model of memory where only the probability of retrieval can be affected, while the retrieval time is drawn from the same distribution; in this model, differences in latencies are a by-product of the possibility of backtracking and repairing incorrect retrievals. We implemented both models in a Bayesian hierarchical framework in order to evaluate them and compare them. The data show that correct retrievals take longer than incorrect ones, and this pattern is better fit under the direct-access model than under the activation-based model. This finding does not rule out the possibility that retrieval may be behaving as a race model with assumptions that follow less closely the ones from the ACT-R framework. By introducing a modification of the activation model, i.e., by assuming that the accumulation of evidence for retrieval of incorrect items is not only slower but noisier (i.e., different variances for the correct and incorrect items), the model can provide a fit as good as the one of the direct-access model. This first ever computational evaluation of alternative accounts of retrieval processes in sentence processing opens the way for a broader investigation of theories of dependency completion.
KW - Cognitive modeling
KW - Sentence processing
KW - Working memory
KW - Cue-based retrieval
KW - Similarity-based interference
KW - Bayesian hierarchical modeling
Y1 - 2018
U6 - https://doi.org/10.1016/j.jml.2017.08.004
SN - 0749-596X
SN - 1096-0821
VL - 99
SP - 1
EP - 34
PB - Elsevier
CY - San Diego
ER -
TY - JOUR
A1 - Wu, Fuyun
A1 - Kaiser, Elsi
A1 - Vasishth, Shravan
T1 - Effects of early cues on the processing of chinese relative clauses
BT - evidence for experience-based theories
JF - Cognitive science : a multidisciplinary journal of anthropology, artificial intelligence, education, linguistics, neuroscience, philosophy, psychology ; journal of the Cognitive Science Society
N2 - We used Chinese prenominal relative clauses (RCs) to test the predictions of two competing accounts of sentence comprehension difficulty: the experience-based account of Levy () and the Dependency Locality Theory (DLT; Gibson, ). Given that in Chinese RCs, a classifier and/or a passive marker BEI can be added to the sentence-initial position, we manipulated the presence/absence of classifiers and the presence/absence of BEI, such that BEI sentences were passivized subject-extracted RCs, and no-BEI sentences were standard object-extracted RCs. We conducted two self-paced reading experiments, using the same critical stimuli but somewhat different filler items. Reading time patterns from both experiments showed facilitative effects of BEI within and beyond RC regions, and delayed facilitative effects of classifiers, suggesting that cues that occur before a clear signal of an upcoming RC can help Chinese comprehenders to anticipate RC structures. The data patterns are not predicted by the DLT, but they are consistent with the predictions of experience-based theories.
KW - Storage cost
KW - Experience
KW - Relative clause
KW - Chinese
KW - Classifiers
KW - BEI
Y1 - 2017
U6 - https://doi.org/10.1111/cogs.12551
SN - 0364-0213
SN - 1551-6709
VL - 42
SP - 1101
EP - 1133
PB - Wiley
CY - Hoboken
ER -