scholarly journals Controlling precedence in sequential stimulus presentation with Euler tours

2021 ◽  
Author(s):  
Jacob Johannes Willem Bakermans ◽  
Timothy E.J. Behrens
Keyword(s):  
Stimulus Presentation ◽  
Stimulus Order ◽  
History Effects ◽  
Repetition Suppression ◽  
Euler Tours ◽  
Generating Sequences

It is important to control for stimulus history in experiments probing responses to and similarity between sequentially presented stimuli. We present a method for stimulus order randomisation that guarantees identical precedence across stimuli. Generating sequences through sampling Euler tours allows for perfectly uniform stimulus history. This deconfounds the stimulus history from the present stimulus and maximises sensitivity to stimulus history effects including repetition suppression.

Object-Selective Cortex Exhibits Performance-Independent Repetition Suppression

2006 ◽  
Vol 95 (2) ◽  
pp. 995-1007 ◽  
Author(s):  
Rory Sayres ◽  
Kalanit Grill-Spector
Keyword(s):  
Response Time ◽  
Response Times ◽  
Recognition Performance ◽  
Region Of Interest ◽  
Stimulus Presentation ◽  
Repetition Suppression ◽  
Fmri Study ◽  
Bold Responses ◽  
Cortical Regions ◽  
Time Required

Object-selective cortical regions exhibit a decreased response when an object stimulus is repeated [repetition suppression (RS)]. RS is often associated with priming: reduced response times and increased accuracy for repeated stimuli. It is unknown whether RS reflects stimulus-specific repetition, the associated changes in response time, or the combination of the two. To address this question, we performed a rapid event-related functional MRI (fMRI) study in which we measured BOLD signal in object-selective cortex, as well as object recognition performance, while we manipulated stimulus repetition. Our design allowed us to examine separately the roles of response time and repetition in explaining RS. We found that repetition played a robust role in explaining RS: repeated trials produced weaker BOLD responses than nonrepeated trials, even when comparing trials with matched response times. In contrast, response time played a weak role in explaining RS when repetition was controlled for: it explained BOLD responses only for one region of interest (ROI) and one experimental condition. Thus repetition suppression seems to be mostly driven by repetition rather than performance changes. We further examined whether RS reflects processes occurring at the same time as recognition or after recognition by manipulating stimulus presentation duration. In one experiment, durations were longer than required for recognition (2 s), whereas in a second experiment, durations were close to the minimum time required for recognition (85–101 ms). We found significant RS for brief presentations (albeit with a reduced magnitude), which again persisted when controlling for performance. This suggests a substantial amount of RS occurs during recognition.

scholarly journals Perceptual Expectations do not Modulate Image Repetition Effects as Measured by Event-Related Potentials

2017 ◽  
Author(s):  
Daniel Feuerriegel ◽  
Owen Churches ◽  
Scott Coussens ◽  
Hannah A. D. Keage
Keyword(s):  
Event Related Potentials ◽  
Stimulus Presentation ◽  
Repetition Effect ◽  
Stimulus Onset ◽  
List Type ◽  
Stimulus Repetition ◽  
Repetition Effects ◽  
Neuron Response ◽  
Repetition Suppression ◽  
Related Potentials

AbstractRepeated stimulus presentation leads to complex changes in cortical neuron response properties, commonly known as repetition suppression or stimulus-specific adaptation. Circuit-based models of repetition suppression provide a framework for investigating patterns of repetition effects that propagate through cortical hierarchies. To further develop such models it is critical to determine whether (and if so, when) repetition effects are modulated by top-down influences, such as those related to perceptual expectation. We investigated this by presenting pairs of repeated and alternating face images, and orthogonally manipulating expectations regarding the likelihood of stimulus repetition. Event-related potentials (ERPs) were recorded from n=39 healthy adults, to map the spatiotemporal progression of stimulus repetition and expectation effects, and interactions between these factors, using mass univariate analyses. We also tested whether the ability to predict unrepeated (compared to repeated) face identities could influence the magnitude of observed repetition effects, by presenting separate blocks with predictable and unpredictable alternating faces. Multiple repetition and expectation effects were identified between 99-800ms from stimulus onset, which did not statistically interact at any point. Repetition effects in blocks with predictable alternating faces were smaller than in unpredictable alternating face blocks between 117-179ms and 506-652ms, and larger between 246-428ms. ERP repetition effects appear not to be modulated by perceptual expectations, supporting separate mechanisms for repetition and expectation suppression. However, previous studies that aimed to test for repetition effects, in which the repeated (but not unrepeated) stimulus was predictable, are likely to have conflated repetition and stimulus predictability effects.Highlights- ERP face image repetition effects were apparent between 99-800ms from stimulus onset- Expectations of stimulus image properties did not modulate face repetition effects- The predictability of unrepeated stimuli influenced repetition effect magnitudes

Probability Strategies in Similar Concurrent Tasks as a Function of Instructions and Stimulus-Presentation Conditions

1973 ◽  
Vol 32 (2) ◽  
pp. 375-380
Author(s):  
Herbert U. Schenck ◽  
Colleen Surber
Keyword(s):  
Probability Learning ◽  
Stimulus Presentation ◽  
Correct Choice ◽  
Individual Behavior ◽  
Stimulus Order ◽  
Concurrent Tasks ◽  
Choice Tasks

48 adults learned 2 concurrent 4-choice tasks with 70% probable reinforcement for the correct choice. Stimuli for the 2 tasks were presented in 3 orders, and 2 instruction conditions were used. One stimulus order led to more maximization than the others, and 48% of the Ss changed strategies between the 2 tasks. Questions about the predictability of individual behavior in probability-learning situations are discussed.

Acquisition of Visual-Auditory Associations by Good and Excellent Readers

1972 ◽  
Vol 35 (3) ◽  
pp. 847-855 ◽  
Author(s):  
Bonnie N. Bartholomeus ◽  
D. G. Doehring
Keyword(s):  
Reading Instruction ◽  
Visual Stimuli ◽  
Stimulus Presentation ◽  
Visual Presentation ◽  
Order Effect ◽  
Good Readers ◽  
Reading Groups ◽  
Stimulus Order ◽  
Order And Type ◽  
Stimulus Modalities

The acquisition of visual-auditory associations was studied in 96 7-yr.-old Ss who had successfully completed 1 yr. of reading instruction. The effects of reading status, stimulus order, and type of associative task were assessed. Children classified as Excellent Readers made significantly fewer errors in learning the associative tasks than did children classified as Good Readers. Visual-preceding-auditory stimulus presentation was consistently easier than auditory-preceding-visual presentation for Good Readers; whereas this order effect was limited to tasks involving verbal visual stimuli for Excellent Readers. For both reading groups associations involving verbal visual stimuli were more difficult than those involving nonverbal visual stimuli. There were no significant differences between associative tasks involving verbal and nonverbal sounds, and no significant interaction of stimulus modalities with the verbal-nonverbal characteristics of the stimuli. The results were compared with those obtained in a previous study with adult Ss.

scholarly journals Neural Correlates of Value Are Intrinsically History Dependent

2020 ◽  
Author(s):  
Sangil Lee ◽  
Caryn Lerman ◽  
Joseph W. Kable
Keyword(s):  
Population Level ◽  
Neural Correlates ◽  
Practical Application ◽  
Efficient Coding ◽  
Decision Neuroscience ◽  
History Effects ◽  
Repetition Suppression ◽  
Subjective Value ◽  
Out Of Sample ◽  
Prediction Approach

AbstractA central finding in decision neuroscience is that BOLD activity in several regions, including ventral striatum and ventromedial prefrontal cortex, is correlated with the subjective value of the option being considered, and that BOLD activity in these regions can predict choices out of sample, even at the population-level. Here we show, across two different decision making tasks in a large sample of subjects, that these BOLD value-correlates are intrinsically history dependent. If the subjective value of the previous offer was high, the signal on the current trial will be lower, and vice versa. This kind of history dependency is distinct from previously described adaptation or repetition suppression effects, but instead is of the form predicted by theories of efficient coding such as time-dependent cortical normalization. In terms of practical application, since value-based choice behavior does not exhibit the same history dependence, neural prediction studies may exhibit systematic errors without accounting for history effects. The data-driven, interpretable, whole-brain prediction approach we use to identify history effects also illustrates one way to adjust predictions for neural history dependency.

scholarly journals Top-down resolution of visual ambiguity – knowledge from the future or footprints from the past?

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258667
Author(s):  
Jürgen Kornmeier ◽  
Kriti Bhatia ◽  
Ellen Joos
Keyword(s):  
A Priori ◽  
Necker Cube ◽  
Experimental Studies ◽  
Sensory Information ◽  
Stimulus Presentation ◽  
Point Of View ◽  
History Effects ◽  
The Future ◽  
Experimental Findings ◽  
And Behavior

Current theories about visual perception assume that our perceptual system weights the a priori incomplete, noisy and ambiguous sensory information with previous, memorized perceptual experiences in order to construct stable and reliable percepts. These theories are supported by numerous experimental findings. Theories about precognition have an opposite point of view. They assume that information from the future can have influence on perception, thoughts, and behavior. Several experimental studies provide evidence for precognition effects, other studies found no such effects. One problem may be that the vast majority of precognition paradigms did not systematically control for potential effects from the perceptual history. In the present study, we presented ambiguous Necker cube stimuli and disambiguated cube variants and systematically tested in two separate experiments whether perception of a currently observed ambiguous Necker cube stimulus can be influenced by a disambiguated cube variant, presented in the immediate perceptual past (perceptual history effects) and/or in the immediate perceptual future (precognition effects). We found perceptual history effects, which partly depended on the length of the perceptual history trace but were independent of the perceptual future. Results from some individual participants suggest on the first glance a precognition pattern, but results from our second experiment make a perceptual history explanation more probable. On the group level, no precognition effects were statistically indicated. The perceptual history effects found in the present study are in confirmation with related studies from the literature. The precognition analysis revealed some interesting individual patterns, which however did not allow for general conclusions. Overall, the present study demonstrates that any future experiment about sensory or extrasensory perception urgently needs to control for potential perceptual history effects and that temporal aspects of stimulus presentation are of high relevance.

Effect of Stimulus Order on Verbal and Nonverbal Visual-Auditory Association

1971 ◽  
Vol 33 (3) ◽  
pp. 891-897 ◽  
Author(s):  
Bonnie N. Bartholomeus ◽  
Donald G. Doehring
Keyword(s):  
Visual Stimuli ◽  
Stimulus Presentation ◽  
Auditory Stimuli ◽  
Verbal Stimuli ◽  
Stimulus Order

The acquisition of visual-auditory associations was studied in 96 adult Ss to assess the effect of order of stimulus presentation and differences between verbal and nonverbal stimuli. Associations involving verbal sounds were learned more easily than those involving nonverbal sounds when the sounds were presented at the same time or following visual stimuli, but the associative task was relatively difficult when verbal sounds preceded verbal visual stimuli. Associations involving nonverbal visual stimuli were learned more easily than those involving verbal stimuli when visual stimuli followed auditory stimuli.

scholarly journals Encoding of Predictable and Unpredictable Stimuli by Inferior Temporal Cortical Neurons

2017 ◽  
Vol 29 (8) ◽  
pp. 1445-1454 ◽  
Author(s):  
Susheel Kumar ◽  
Peter Kaposvari ◽  
Rufin Vogels
Keyword(s):  
Cortical Neurons ◽  
Random Sequence ◽  
Stimulus Presentation ◽  
Stimulus Order ◽  
Standard Sequence ◽  
Activation Level ◽  
Statistical Regularities ◽  
Image Identity ◽  
Transitional Probabilities ◽  
Decoding Accuracy

Animals and humans learn statistical regularities that are embedded in sequences of stimuli. The neural mechanisms of such statistical learning are still poorly understood. Previous work in macaque inferior temporal (IT) cortex demonstrated suppressed spiking activity to visual images of a sequence in which the stimulus order was defined by transitional probabilities (labeled as “standard” sequence), compared with a sequence in which the stimulus order was random (“random” sequence). Here, we asked whether IT neurons encode the images of the standard sequence more accurately compared with images of the random sequence. Previous human fMRI studies in different sensory modalities also found a suppressed response to expected relative to unexpected stimuli but obtained various results regarding the effect of expectation on encoding, with one study reporting an improved classification accuracy of expected stimuli despite the reduced activation level. We employed a linear classifier to decode image identity from the spiking responses of the recorded IT neurons. We found a greater decoding accuracy for images of the standard compared with the random sequence during the early part of the stimulus presentation, but further analyses suggested that this reflected the sustained, stimulus-selective activity from the previous stimulus of the sequence, which is typical for IT neurons. However, the peak decoding accuracy was lower for the standard compared with the random sequence, in line with the reduced response to the former compared with the latter images. These data suggest that macaque IT neurons represent less accurately predictable compared with unpredictable images.

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