scholarly journals Evidence Accumulation Modelling Reveals that Gaussian Noise Accounts for Inhibition of Return

2020 ◽  
Author(s):  
Tal Seidel Malkinson ◽  
Alexia Bourgeois ◽  
Nicolas Wattiez ◽  
Pierre Pouget ◽  
Paolo Bartolomeo

AbstractInhibition of return (IOR) refers to the slowing of response times (RTs) for stimuli repeated at previously inspected locations, as compared with novel ones. However, the exact processing stage(s) at which IOR occurs, and its nature across different response modalities, remain debated. We tested predictions on these issues originating from the FORTIOR model (fronto-parietal organization of response times in IOR; Seidel Malkinson & Bartolomeo, 2018), and from evidence accumulation models. We reanalysed RT data from a target-target IOR paradigm (Bourgeois et al.,2013a, 2013b) by using a LATER-like evidence accumulation model (Carpenter & Williams, 1995), to test the predictions of FORTIOR, and specifically whether IOR could occur at sensory/attentional stages of processing, or at stages of decision and action selection. We considered the following conditions: manual or saccadic response modality, before or after TMS perturbation over four cortical regions. Results showed that the Gaussian noise parameter best explained both manual and saccadic IOR, suggesting that in both response modalities IOR may result from slower accumulation of evidence for repeated locations. Additionally, across stimulated regions, TMS affected only manual RTs, lowering them equally in the conditions with repeated targets (Return) and non-repeated targets (Non-return). Accordingly, the modelling results show that TMS stimulation did not significantly alter the pattern between model parameters, with the Gaussian noise parameter remaining the parameter best explaining the Return - Non-return RT difference. Moreover, TMS over the right intra-parietal sulcus (IPS) perturbed IOR by shortening the Return RT. When directly testing this effect by modelling the TMS impact in the Return condition, the Bayesian information criterion of the Gaussian noise parameter was the smallest, but this effect did not reach significance. These results support the hypothesis that target-target IOR is a predominantly sensory/attentional phenomenon, and may be modulated by activity in fronto-parietal networks.

2017 ◽  
Author(s):  
Tal Seidel Malkinson ◽  
Paolo Bartolomeo

Inhibition of Return (IOR) refers to a slowing of response times (RTs) for visual stimuli repeated at the same spatial location, as compared to stimuli occurring at novel locations. The functional mechanisms and the neural bases of this phenomenon remain debated. Here we present FORTIOR, a model of the cortical control of visual IOR in the human brain. The model is based on known facts about the anatomical and functional organization of fronto-parietal attention networks, and accounts for a broad range of behavioral findings in healthy participants and brain-damaged patients. FORTIOR does that by combining four principles of asymmetry: a) Asymmetry in the networks topography, whereby the temporoparietal junction (TPJ) and ventrolateral prefrontal cortex (vlPFC) nodes are lateralized to the right hemisphere, causing higher activation levels in the right intraparietal sulcus (IPS) and frontal eye field (FEF) nodes. b) Asymmetry in inter-hemispheric connectivity, in which inter-hemispheric connections from left hemisphere IPS to right hemisphere IPS and from left hemisphere FEF to right hemisphere FEF are weaker than in the opposite direction. c) Asymmetry of visual inputs, stipulating that the FEF receives direct visual input coming from the ipsilateral visual cortex, while the right TPJ and vlPFC and IPS nodes receive input from both the contralateral and the ipsilateral visual fields. d) Asymmetry in the response modality, with a higher response threshold for the manual response system than that required to trigger a saccadic response. This asymmetry results in saccadic IOR being more robust to interference than manual IOR. FORTIOR accounts for spatial asymmetries in the occurrence of IOR after brain damage and after non-invasive transcranial magnetic stimulation on parietal and frontal regions. It also provides a framework to understand dissociations between manual and saccadic IOR, and makes testable predictions for future experiments to assess its validity.


2002 ◽  
Vol 14 (2) ◽  
pp. 127-144 ◽  
Author(s):  
Jöran Lepsien ◽  
Stefan Pollmann

Using event-related fMRI, we analyzed the functional neuroanatomy of covert reorienting and inhibition of return (IOR). Covert reorienting to a target appearing within 250 msec after an invalid contralateral location cue elicited increased activation in the left fronto-polar cortex (LFPC), right anterior and left posterior middle frontal gyrus, and right cerebellum, areas that have previously been associated with attentional processes, specifically attentional change. In contrast, IOR, which leads to prolonged response times to targets that appear at the cued location at a stimulus-onset-asynchrony (SOA)>250 msec, was accompanied by increased activation in brain areas involved in oculomotor programming, such as the right medial frontal gyrus (supplementary eye field; SEF) and the right inferior precentral sulcus (frontal eye field; FEF), supporting the oculomotor bias theory of IOR. Pre-SEF and pre-FEF areas were involved both in covert reorienting and IOR. The supramarginal gyri were bilaterally involved in IOR, with the right supramarginal gyrus additionally involved in covert reorienting.


2017 ◽  
Vol 29 (3) ◽  
pp. 804-824 ◽  
Author(s):  
W. Joseph MacInnes

Cuing a location in space produces a short-lived advantage in reaction time to targets at that location. This early advantage, however, switches to a reaction time cost and has been termed inhibition of return (IOR). IOR behaves differently for different response modalities, suggesting that it may not be a unified effect. This letter presents new data from two experiments testing the gradient of IOR with random, continuous cue-target Euclidean distance and cue-target onset asynchrony. These data were then used to train multiple diffusion models of saccadic and manual reaction time for these cuing experiments. Diffusion models can generate accurate distributions of reaction time data by modeling a response as a buildup of evidence toward a response threshold. If saccadic and attentional IOR are based on similar processes, then differences in distribution will be best explained by adjusting parameter values such as signal and noise within the same model structure. Although experimental data show differences in the timing of IOR across modality, best-fit models are shown to have similar model parameters for the gradient of IOR, suggesting similar underlying mechanisms for saccadic and manual IOR.


2011 ◽  
Vol 23 (6) ◽  
pp. 1522-1532 ◽  
Author(s):  
Maki Suzuki ◽  
Jeffrey D. Johnson ◽  
Michael D. Rugg

fMRI (1.5 mm isotropic voxels) was employed to investigate the relationship between hippocampal activity and memory strength in a continuous recognition task. While being scanned, subjects were presented with colored photographs that each appeared on four occasions. The requirements were to make one response when an item was presented for the first or the third time and to make a different response when an item appeared for the second or the fourth time. Consistent with prior findings, items presented for the first time elicited greater hippocampal and parahippocampal activity than repeated items. The activity elicited by repeated items declined linearly as a function of number of presentations (“graded” new > old effects). No medial-temporal lobe regions could be identified where activity elicited by repeated items exceeded that for new items or where activity elicited by repeated items increased with number of presentations. These findings are inconsistent with the proposal that retrieval-related hippocampal activity is positively correlated with memory strength. We also identified graded new > old effects in several cortical regions outside the medial-temporal lobe, including the left retrosplenial/posterior cingulate cortex and the right lateral occipito-temporal cortex. By contrast, graded old > new effects were evident in bilateral mid-intraparietal sulcus and precuneus.


2021 ◽  
Vol 11 (8) ◽  
pp. 960
Author(s):  
Mina Kheirkhah ◽  
Philipp Baumbach ◽  
Lutz Leistritz ◽  
Otto W. Witte ◽  
Martin Walter ◽  
...  

Studies investigating human brain response to emotional stimuli—particularly high-arousing versus neutral stimuli—have obtained inconsistent results. The present study was the first to combine magnetoencephalography (MEG) with the bootstrapping method to examine the whole brain and identify the cortical regions involved in this differential response. Seventeen healthy participants (11 females, aged 19 to 33 years; mean age, 26.9 years) were presented with high-arousing emotional (pleasant and unpleasant) and neutral pictures, and their brain responses were measured using MEG. When random resampling bootstrapping was performed for each participant, the greatest differences between high-arousing emotional and neutral stimuli during M300 (270–320 ms) were found to occur in the right temporo-parietal region. This finding was observed in response to both pleasant and unpleasant stimuli. The results, which may be more robust than previous studies because of bootstrapping and examination of the whole brain, reinforce the essential role of the right hemisphere in emotion processing.


Mathematics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 910
Author(s):  
Andrey Kovtanyuk ◽  
Alexander Chebotarev ◽  
Varvara Turova ◽  
Irina Sidorenko ◽  
Renée Lampe

An inverse problem for a system of equations modeling oxygen transport in the brain is studied. The problem consists of finding the right-hand side of the equation for the blood oxygen transport, which is a linear combination of given functionals describing the average oxygen concentration in the neighborhoods of the ends of arterioles and venules. The overdetermination condition is determined by the values of these functionals evaluated on the solution. The unique solvability of the problem is proven without any smallness assumptions on the model parameters.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Roger Ratcliff ◽  
Inhan Kang

AbstractRafiei and Rahnev (2021) presented an analysis of an experiment in which they manipulated speed-accuracy stress and stimulus contrast in an orientation discrimination task. They argued that the standard diffusion model could not account for the patterns of data their experiment produced. However, their experiment encouraged and produced fast guesses in the higher speed-stress conditions. These fast guesses are responses with chance accuracy and response times (RTs) less than 300 ms. We developed a simple mixture model in which fast guesses were represented by a simple normal distribution with fixed mean and standard deviation and other responses by the standard diffusion process. The model fit the whole pattern of accuracy and RTs as a function of speed/accuracy stress and stimulus contrast, including the sometimes bimodal shapes of RT distributions. In the model, speed-accuracy stress affected some model parameters while stimulus contrast affected a different one showing selective influence. Rafiei and Rahnev’s failure to fit the diffusion model was the result of driving subjects to fast guess in their experiment.


Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 272
Author(s):  
Ning Li ◽  
Junli Xu ◽  
Xianqing Lv

Numerous studies have revealed that the sparse spatiotemporal distributions of ground-level PM2.5 measurements affect the accuracy of PM2.5 simulation, especially in large geographical regions. However, the high precision and stability of ground-level PM2.5 measurements make their role irreplaceable in PM2.5 simulations. This article applies a dynamically constrained interpolation methodology (DCIM) to evaluate sparse PM2.5 measurements captured at scattered monitoring sites for national-scale PM2.5 simulations and spatial distributions. The DCIM takes a PM2.5 transport model as a dynamic constraint and provides the characteristics of the spatiotemporal variations of key model parameters using the adjoint method to improve the accuracy of PM2.5 simulations. From the perspective of interpolation accuracy and effect, kriging interpolation and orthogonal polynomial fitting using Chebyshev basis functions (COPF), which have been proved to have high PM2.5 simulation accuracy, were adopted to make a comparative assessment of DCIM performance and accuracy. Results of the cross validation confirm the feasibility of the DCIM. A comparison between the final interpolated values and observations show that the DCIM is better for national-scale simulations than kriging or COPF. Furthermore, the DCIM presents smoother spatially interpolated distributions of the PM2.5 simulations with smaller simulation errors than the other two methods. Admittedly, the sparse PM2.5 measurements in a highly polluted region have a certain degree of influence on the interpolated distribution accuracy and rationality. To some extent, adding the right amount of observations can improve the effectiveness of the DCIM around existing monitoring sites. Compared with the kriging interpolation and COPF, the results show that the DCIM used in this study would be more helpful for providing reasonable information for monitoring PM2.5 pollution in China.


2007 ◽  
Vol 18 (9) ◽  
pp. 783-787 ◽  
Author(s):  
Thomas M. Spalek

An object hidden among distractors can be found more efficiently if previously searched locations are not reinspected. The inhibition-of-return (IOR) phenomenon indexes the tendency to avoid reinspections. Two accounts of IOR, that it is due to inhibition and that it is due to expectation, are generally regarded as incompatible. The relevant evidence to date, however, has been indirect: Inhibition or expectation has been inferred from response times or similar indirect measures. This article reports the first direct measure of IOR, obtained by asking observers to predict the location of the next target in a display containing eight possible locations on an imaginary circle. On any given trial, the previously cued location was chosen less frequently (impairment)—and the opposite location was chosen more frequently (facilitation)—than chance (choice of all other locations was at chance). The impairment is consistent with both inhibition and expectation accounts; the facilitation is consistent only with expectation accounts. This work also shows that inhibition and expectation are not necessarily incompatible: Implementing expectations may entail inhibiting previously cued locations.


2010 ◽  
Vol 23 (1) ◽  
pp. 149-154 ◽  
Author(s):  
Shou-Hung Huang ◽  
Shang-Ying Tsai ◽  
Jung-Lung Hsu ◽  
Yi-Lin Huang

ABSTRACTBackground: Few studies have examined alterations of the brain in elderly bipolar patients. As late-onset mania is associated with increased cerebrovascular morbidity and neurological damage compared with typical/early-onset mania, we investigated differences in the volume of various cortical regions between elderly patients with early-onset versus late-onset mania.Methods: We recruited 44 bipolar patients aged over 60 years, who underwent volumetric magnetic resonance imaging at 1.5 T. The analytic method is based on the hidden Markov random field model with an expectation-maximization algorithm. We determined the volume of each cortical region as a percentage of the total intracranial volume. The cutoff age for defining early versus late onset was 45 years.Results: The study participants consisted of 25 patients with early-onset mania and 19 patients with late-onset mania; their mean ages were 65.7 years and 62.8 years, respectively. The demographic variables of the two groups were comparable. The volumes of the left caudate nucleus (p = 0.022) and left middle frontal gyrus (p = 0.013) were significantly greater and that of the right posterior cingulate gyrus (p = 0.019) was significantly smaller in the late-onset group. More patients with late-onset mania had comorbid cerebrovascular disease (p = 0.072).Conclusions: The right posterior cingulate gyrus is smaller and the left caudate nucleus and left middle frontal gyrus are larger in patients with late-onset mania compared with those with early-onset mania. Volumetric change in brain regions may vary in elderly bipolar patients with early and late-onset mania.


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