scholarly journals Inhibition failures and late errors in the antisaccade task: influence of cue delay

2018 ◽  
Vol 120 (6) ◽  
pp. 3001-3016 ◽  
Author(s):  
Eduardo A. Aponte ◽  
Dominic G. Tschan ◽  
Klaas E. Stephan ◽  
Jakob Heinzle
Keyword(s):  
Quantitative Analysis ◽  
Contextual Effects ◽  
Summary Statistics ◽  
Antisaccade Task ◽  
Voluntary Response ◽  
Early Reaction ◽  
Underlying Processes ◽  
Reflexive Saccades ◽  
Reaction Inhibition ◽  
Types Of Error

In the antisaccade task participants are required to saccade in the opposite direction of a peripheral visual cue (PVC). This paradigm is often used to investigate inhibition of reflexive responses as well as voluntary response generation. However, it is not clear to what extent different versions of this task probe the same underlying processes. Here, we explored with the Stochastic Early Reaction, Inhibition, and late Action (SERIA) model how the delay between task cue and PVC affects reaction time (RT) and error rate (ER) when pro- and antisaccade trials are randomly interleaved. Specifically, we contrasted a condition in which the task cue was presented before the PVC with a condition in which the PVC served also as task cue. Summary statistics indicate that ERs and RTs are reduced and contextual effects largely removed when the task is signaled before the PVC appears. The SERIA model accounts for RT and ER in both conditions and better so than other candidate models. Modeling demonstrates that voluntary pro- and antisaccades are frequent in both conditions. Moreover, early task cue presentation results in better control of reflexive saccades, leading to fewer fast antisaccade errors and more rapid correct prosaccades. Finally, high-latency errors are shown to be prevalent in both conditions. In summary, SERIA provides an explanation for the differences in the delayed and nondelayed antisaccade task.NEW & NOTEWORTHY In this article, we use a computational model to study the mixed antisaccade task. We contrast two conditions in which the task cue is presented either before or concurrently with the saccadic target. Modeling provides a highly accurate account of participants’ behavior and demonstrates that a significant number of prosaccades are voluntary actions. Moreover, we provide a detailed quantitative analysis of the types of error that occur in pro- and antisaccade trials.

scholarly journals The Stochastic Early Reaction, Inhibition, and Late Action (SERIA) Model for Antisaccades

2017 ◽  
Author(s):  
Eduardo A. Aponte ◽  
Dario Schoebi ◽  
Klaas E. Stephan ◽  
Jakob Heinzle
Keyword(s):  
Decision Process ◽  
Model Comparison ◽  
Reaction Times ◽  
Error Rates ◽  
Decision Processes ◽  
Antisaccade Task ◽  
Data Set ◽  
Early Reaction ◽  
Experimental Findings ◽  
Reaction Inhibition

AbstractThe antisaccade task is a classic paradigm used to study the voluntary control of eye movements. It requires participants to suppress a reactive eye movement to a visual target and to concurrently initiate a saccade in the opposite direction. Although several models have been proposed to explain error rates and reaction times in this task, no formal model comparison has yet been performed. Here, we describe a Bayesian modeling approach to the antisaccade task that allows us to formally compare different models on the basis of their evidence. First, we provide a formal likelihood function of actions (pro- and antisaccades) and reaction times based on previously published models. Second, we introduce theStochastic Early Reaction, Inhibition, and late Action model(SERIA), a novel model postulating two different mechanisms that interact in the antisaccade task: an early GO/NO-GO race decision process and a late GO/GO decision process. Third, we apply these models to a data set from an experiment with three mixed blocks of pro- and antisaccade trials. Bayesian model comparison demonstrates that the SERIA model explains the data better than competing models that do not incorporate a late decision process. Moreover, we show that the race decision processes postulated by the SERIA model are, to a large extent, insensitive to the cue presented on a single trial. Finally, we use parameter estimates to demonstrate that changes in reaction time and error rate due to the probability of a trial type (prosaccade or antisaccade) are best explained by faster or slower inhibition and the probability of generating late voluntary prosaccades.Author summaryOne widely replicated finding in schizophrenia research is that patients tend to make more errors in the antisaccade task, a psychometric paradigm in which participants are required to look in the opposite direction of a visual cue. This deficit has been suggested to be an endophenotype of schizophrenia, as first order relatives of patients tend to show similar but milder deficits. Currently, most models applied to experimental findings in this task are limited to fit average reaction times and error rates. Here, we propose a novel statistical model that fits experimental data from the antisaccade task, beyond summary statistics. The model is inspired by the hypothesis that antisaccades are the result of several competing decision processes that interact nonlinearly with each other. In applying this model to a relatively large experimental data set, we show that mean reaction times and error rates do not fully reflect the complexity of the processes that are likely to underlie experimental findings. In the future, our model could help to understand the nature of the deficits observed in schizophrenia by providing a statistical tool to study their biological underpinnings.

Disturbances in the Control of Saccadic Eye Movement and Eye-Head Coordination in Schizophrenics1

1991 ◽  
Vol 1 (2) ◽  
pp. 171-180
Author(s):  
Junko Fukushima ◽  
Kikuro Fukushima ◽  
Nobuyuki Morita ◽  
Itaru Yamashita
Keyword(s):  
Frontal Cortex ◽  
Head Movement ◽  
Head Movements ◽  
Saccadic Eye Movement ◽  
Antisaccade Task ◽  
Schizophrenic Patients ◽  
Saccade Task ◽  
Cortical Dysfunction ◽  
Reflexive Saccades ◽  
Target Memory

Some schizophrenic patients have been known to have frontal cortical dysfunction. In view of the evidence that voluntary purposive eye movements and rapid head movements involve areas of the frontal cortex, investigations of saccade performance have been carried out on schizophrenics in various laboratories. We have compared performance of schizophrenic patients in tasks involving inhibition of reflexive saccades (no-saccade) and initiation of saccades without target (memory-saccade) with performance in. the antisaccade task. These measures were also compared with results of eye-head coordination tasks. Schizophrenics showed more errors and significantly longer latencies, with lower peak velocities at large amplitudes, in both the anti saccade task and the memory-saccade task. Performance with coordinated eye-head movement was basically similar, except for significantly longer latencies of head movement. These results suggest that schizophrenics may have a disturbance in initiating and executing purposive saccades without targets, and that dysfunction of the frontal cortex may contribute to this disturbance.

scholarly journals Working Memory and the Suppression of Reflexive Saccades

2002 ◽  
Vol 14 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Jason P. Mitchell ◽  
C. Neil Macrae ◽  
Iain D. Gilchrist
Keyword(s):  
Working Memory ◽  
Memory Load ◽  
Critical Role ◽  
Memory Task ◽  
Behavioral Responses ◽  
Error Rates ◽  
Antisaccade Task ◽  
Working Memory Load ◽  
Reflexive Saccades ◽  
Back Task

Conscious behavioral intentions can frequently fail under conditions of attentional depletion. In attempting to trace the cognitive origin of this effect, we hypothesized that failures of action control—specifically, oculomotor movement—can result from the imposition of fronto-executive load. To evaluate this prediction, participants performed an antisaccade task while simultaneously completing a working-memory task that is known to make variable demands on prefrontal processes (n-back task, see Jonides et al., 1997). The results of two experiments are reported. As expected, antisaccade error rates were increased in accordance with the fronto-executive demands of the n-back task (Experiment 1). In addition, the debilitating effects of working-memory load were restricted to the inhibitory component of the antisaccade task (Experiment 2). These findings corroborate the view that working memory operations play a critical role in the suppression of prepotent behavioral responses.

Children's overregularization of English plurals: a quantitative analysis

1995 ◽  
Vol 22 (2) ◽  
pp. 447-459 ◽  
Author(s):  
Gary F. Marcus
Keyword(s):  
Quantitative Analysis ◽  
Quantitative Study ◽  
Past Tense ◽  
Default Rule ◽  
Failure Model ◽  
Connectionist Models ◽  
Retrieval Failure ◽  
English Speaking ◽  
Past Tenses ◽  
Underlying Processes

ABSTRACTThis paper brings a quantitative study of children's noun plural overregularizations (foots, mans) to bear on recent comparisons of connectionist and symbolic models of language. The speech of 10 English-speaking children (aged 1;3 to 5;2) from the CHILDES database (MacWhinney & Snow, 1985, 1990) were analysed. The rate of noun overregularization is low, mean = 8·5%, demonstrating that children prefer correct to overregularized forms. Rates of noun overregularization are not significantly different from their rates of past tense overregularization, and noun plurals, like verb past tenses, follow a U-shaped developmental curve in which correct irregulars precede the first overregularized forms. These facts suggest that plural and past tense overregularizations are caused by similar underlying processes. The results pose challenges to connectionist models, but are consistent with Marcuset al.'s(1992) blocking-and-retrieval-failure model in which regulars are generated by a default rule while irregulars are retrieved from the lexicon.

scholarly journals Suppression of reflexive saccades in younger and older adults: Age comparisons on an antisaccade task

1999 ◽  
Vol 27 (4) ◽  
pp. 584-591 ◽  
Author(s):  
Karin M. Butler ◽  
Rose T. Zacks ◽  
John M. Henderson
Keyword(s):  
Older Adults ◽  
Antisaccade Task ◽  
Reflexive Saccades

scholarly journals Control of Reflexive Saccades following Hemispherectomy

2011 ◽  
Vol 23 (6) ◽  
pp. 1368-1378 ◽  
Author(s):  
Patricia A. Reuter-Lorenz ◽  
Troy M. Herter ◽  
Daniel Guitton
Keyword(s):  
Superior Colliculus ◽  
Inhibitory Control ◽  
Intractable Epilepsy ◽  
Short Latency ◽  
Gap Effect ◽  
Express Saccades ◽  
Antisaccade Task ◽  
Intact Side ◽  
Reflexive Saccades ◽  
Saccade Generation

Individuals who have undergone hemispherectomy for treatment of intractable epilepsy offer a rare and valuable opportunity to examine the ability of a single cortical hemisphere to control oculomotor performance. We used peripheral auditory events to trigger saccades, thereby circumventing dense postsurgical hemianopia. In an antisaccade task, patients generated numerous unintended short-latency saccades toward contralesional auditory events, indicating pronounced limitations in the ability of a single hemicortex to exert normal inhibitory control over ipsilateral (i.e., contralesional) reflexive saccade generation. Despite reflexive errors, patients retained an ability to generate correct antisaccades in both directions. The prosaccade task revealed numerous contralesional express saccades, a robust contralesional gap effect, but the absence of both effects for ipsilesional saccades. These results indicate limits to the saccadic control capabilities following hemispherectomy: A single hemicortex can mediate antisaccades in both directions, but plasticity does not extend fully to the bilateral inhibition of reflexive saccades. We posit that these effects are due to altered control dynamics that reduce the responsivity of the superior colliculus on the intact side and facilitate the release of an auditory-evoked ocular grasp reflex into the blind hemifield that the intact hemicortex has difficulty suppressing.

scholarly journals The Stochastic Early Reaction, Inhibition, and late Action (SERIA) model for antisaccades

2017 ◽  
Vol 13 (8) ◽  
pp. e1005692 ◽  
Author(s):  
Eduardo A. Aponte ◽  
Dario Schöbi ◽  
Klaas E. Stephan ◽  
Jakob Heinzle
Keyword(s):  
Early Reaction ◽  
Reaction Inhibition

An Improved Quantitative Image Analyser

1977 ◽  
Vol 35 ◽  
pp. 226-227
Author(s):  
J.P. Fallon ◽  
P.J. Gregory ◽  
C.J. Taylor
Keyword(s):  
Feature Extraction ◽  
Quantitative Analysis ◽  
Frequency Content ◽  
General Sense ◽  
Physical Measurements ◽  
Quantitative Image ◽  
Image Analyser ◽  
Automatic Methods ◽  
Quantitative Results

Quantitative image analysis systems have been used for several years in research and quality control applications in various fields including metallurgy and medicine. The technique has been applied as an extension of subjective microscopy to problems requiring quantitative results and which are amenable to automatic methods of interpretation.Feature extraction. In the most general sense, a feature can be defined as a portion of the image which differs in some consistent way from the background. A feature may be characterized by the density difference between itself and the background, by an edge gradient, or by the spatial frequency content (texture) within its boundaries. The task of feature extraction includes recognition of features and encoding of the associated information for quantitative analysis.Quantitative Analysis. Quantitative analysis is the determination of one or more physical measurements of each feature. These measurements may be straightforward ones such as area, length, or perimeter, or more complex stereological measurements such as convex perimeter or Feret's diameter.

Quantification of Silica Uptake by Alveolar Macrophages - An Emperical Scanning Electron Microprobe Method

1982 ◽  
Vol 40 ◽  
pp. 332-333
Author(s):  
V. V. Damiano ◽  
R. P. Daniele ◽  
H. T. Tucker ◽  
J. H. Dauber
Keyword(s):  
Quantitative Analysis ◽  
Alveolar Macrophages ◽  
Bulk Sample ◽  
Silica Particles ◽  
Empirical Method ◽  
Phagocytic Cells ◽  
Calibration Standards ◽  
X Ray ◽  
Accurate Quantitative Analysis ◽  
Scanning Electron

An important example of intracellular particles is encountered in silicosis where alveolar macrophages ingest inspired silica particles. The quantitation of the silica uptake by these cells may be a potentially useful method for monitoring silica exposure. Accurate quantitative analysis of ingested silica by phagocytic cells is difficult because the particles are frequently small, irregularly shaped and cannot be visualized within the cells. Semiquantitative methods which make use of particles of known size, shape and composition as calibration standards may be the most direct and simplest approach to undertake. The present paper describes an empirical method in which glass microspheres were used as a model to show how the ratio of the silicon Kα peak X-ray intensity from the microspheres to that of a bulk sample of the same composition correlated to the mass of the microsphere contained within the cell. Irregular shaped silica particles were also analyzed and a calibration curve was generated from these data.

Lateral resolution of the electron microbeam analysis

1978 ◽  
Vol 36 (1) ◽  
pp. 542-543
Author(s):  
H.J. Dudek
Keyword(s):  
Quantitative Analysis ◽  
Depth Resolution ◽  
Lateral Resolution ◽  
Cylindrical Particle ◽  
Correction Procedure ◽  
X Ray ◽  
Element Concentrations ◽  
Microbeam Analysis ◽  
The Matrix

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S

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