scholarly journals The influence of image masking on object representations during rapid serial visual presentation

2019 ◽  
Author(s):  
Amanda K. Robinson ◽  
Tijl Grootswagers ◽  
Thomas A. Carlson
Keyword(s):  
Stimulus Duration ◽  
Stimulus Presentation ◽  
Visual Presentation ◽  
Abrupt Onset ◽  
Stimulus Onset ◽  
Neural Representation ◽  
Object Representations ◽  
Backward Masking ◽  
Time Resolved ◽  
Visual Objects

AbstractRapid image presentations combined with time-resolved multivariate analysis methods of EEG or MEG (rapid-MVPA) offer unique potential in assessing the temporal limitations of the human visual system. Recent work has shown that multiple visual objects presented sequentially can be simultaneously decoded from M/EEG recordings. Interestingly, object representations reached higher stages of processing for slower image presentation rates compared to fast rates. This fast rate attenuation is probably caused by forward and backward masking from the other images in the stream. Two factors that are likely to influence masking during rapid streams are stimulus duration and stimulus onset asynchrony (SOA). Here, we disentangle these effects by studying the emerging neural representation of visual objects using rapid-MVPA while independently manipulating stimulus duration and SOA. Our results show that longer SOAs enhance the decodability of neural representations, regardless of stimulus presentation duration, suggesting that subsequent images act as effective backward masks. In contrast, image duration does not appear to have a graded influence on object representations. Interestingly, however, decodability was improved when there was a gap between subsequent images, indicating that an abrupt onset or offset of an image enhances its representation. Our study yields insight into the dynamics of object processing in rapid streams, paving the way for future work using this promising approach.

scholarly journals The Neurophysiology of Backward Visual Masking: Information Analysis

1999 ◽  
Vol 11 (3) ◽  
pp. 300-311 ◽  
Author(s):  
Edmund T. Rolls ◽  
Martin J. Tovée ◽  
Stefano Panzeri
Keyword(s):  
Visual Processing ◽  
Visual Information ◽  
Computational Models ◽  
Direct Evidence ◽  
Visual Masking ◽  
Neuronal Response ◽  
Short Soas ◽  
Stimulus Onset ◽  
Backward Masking ◽  
Neuronal Responses

Backward masking can potentially provide evidence of the time needed for visual processing, a fundamental constraint that must be incorporated into computational models of vision. Although backward masking has been extensively used psychophysically, there is little direct evidence for the effects of visual masking on neuronal responses. To investigate the effects of a backward masking paradigm on the responses of neurons in the temporal visual cortex, we have shown that the response of the neurons is interrupted by the mask. Under conditions when humans can just identify the stimulus, with stimulus onset asynchronies (SOA) of 20 msec, neurons in macaques respond to their best stimulus for approximately 30 msec. We now quantify the information that is available from the responses of single neurons under backward masking conditions when two to six faces were shown. We show that the information available is greatly decreased as the mask is brought closer to the stimulus. The decrease is more marked than the decrease in firing rate because it is the selective part of the firing that is especially attenuated by the mask, not the spontaneous firing, and also because the neuronal response is more variable at short SOAs. However, even at the shortest SOA of 20 msec, the information available is on average 0.1 bits. This compares to 0.3 bits with only the 16-msec target stimulus shown and a typical value for such neurons of 0.4 to 0.5 bits with a 500-msec stimulus. The results thus show that considerable information is available from neuronal responses even under backward masking conditions that allow the neurons to have their main response in 30 msec. This provides evidence for how rapid the processing of visual information is in a cortical area and provides a fundamental constraint for understanding how cortical information processing operates.

scholarly journals Temporal variability predicts the magnitude of between-group attentional blink differences in developmental dyslexia: a meta-analysis

2014 ◽  
Author(s):  
Nicholas A Badcock ◽  
Joanna C Kidd
Keyword(s):  
Attentional Blink ◽  
Developmental Dyslexia ◽  
Meta Analysis ◽  
Negative Relationship ◽  
Visual Presentation ◽  
Stimulus Onset ◽  
Future Research ◽  
Temporal Position ◽  
Group Effect ◽  
The Difference

Background. Here we report on a meta-analysis of the attentional blink (AB) research focussed on specific reading impairment, commonly referred to as developmental dyslexia. The AB effect relates to a limitation in the allocation of attention over time and examined in a dual-target rapid serial visual presentation paradigm. When the second target appears in close temporal proximity to the first target, the second target is reported less accurately. Method. A Web of Science search with terms 'dyslexia attentional blink' returned 13 AB experiments (11 papers) conducted with developmental dyslexia (9 were included in this meta-analysis). The main pattern of performance was lower overall accuracy in groups of individuals with dyslexia relative to typically reading peers. That is, a between-group main effect. This meta-analysis examined the size of the between-group effect in relation to physical presentation characteristics, which differed between and within experiments. Results. Four noteworthy variables were related to the between group effect-size; fixation duration (positive relationship, R2 = .89, p <.01, n = 6), maximum temporal position of T2 (negative relationship, R2 = .46, p <.05, n = 9), the difference between the minimum and maximum temporal position of T2 (negative relationship, R2 = .53, p <.05, n = 9), and the stimulus onset asynchrony (negative relationship, R2 = .46, p <.05, n = 9). Discussion. These are discussed with respect to the preparation of task-set, temporal orienting, and speed of processing, recommending these as considerations for future research.

scholarly journals Selective enhancement of object representations through multisensory integration

2019 ◽  
Author(s):  
David A. Tovar ◽  
Micah M. Murray ◽  
Mark T. Wallace
Keyword(s):  
Multisensory Integration ◽  
Sensory Information ◽  
Stimulus Presentation ◽  
Building Blocks ◽  
Object Representations ◽  
The Individual ◽  
And Behavior ◽  
Living Objects ◽  
Selective Enhancement ◽  
The Brain

AbstractObjects are the fundamental building blocks of how we create a representation of the external world. One major distinction amongst objects is between those that are animate versus inanimate. Many objects are specified by more than a single sense, yet the nature by which multisensory objects are represented by the brain remains poorly understood. Using representational similarity analysis of human EEG signals, we show enhanced encoding of audiovisual objects when compared to their corresponding visual and auditory objects. Surprisingly, we discovered the often-found processing advantages for animate objects was not evident in a multisensory context due to greater neural enhancement of inanimate objects—the more weakly encoded objects under unisensory conditions. Further analysis showed that the selective enhancement of inanimate audiovisual objects corresponded with an increase in shared representations across brain areas, suggesting that neural enhancement was mediated by multisensory integration. Moreover, a distance-to-bound analysis provided critical links between neural findings and behavior. Improvements in neural decoding at the individual exemplar level for audiovisual inanimate objects predicted reaction time differences between multisensory and unisensory presentations during a go/no-go animate categorization task. Interestingly, links between neural activity and behavioral measures were most prominent 100 to 200ms and 350 to 500ms after stimulus presentation, corresponding to time periods associated with sensory evidence accumulation and decision-making, respectively. Collectively, these findings provide key insights into a fundamental process the brain uses to maximize information it captures across sensory systems to perform object recognition.Significance StatementOur world is filled with an ever-changing milieu of sensory information that we are able to seamlessly transform into meaningful perceptual experience. We accomplish this feat by combining different features from our senses to construct objects. However, despite the fact that our senses do not work in isolation but rather in concert with each other, little is known about how the brain combines the senses together to form object representations. Here, we used EEG and machine learning to study how the brain processes auditory, visual, and audiovisual objects. Surprisingly, we found that non-living objects, the objects which were more difficult to process with one sense alone, benefited the most from engaging multiple senses.

Temporal-Order Judgment and Reaction Time to Stimuli of Different Rise Times

Perception ◽  
1993 ◽  
Vol 22 (8) ◽  
pp. 963-970 ◽  
Author(s):  
Piotr Jaśkowski
Keyword(s):  
Reaction Time ◽  
Simple Reaction Time ◽  
Temporal Order ◽  
Temporal Order Judgment ◽  
Stimulus Presentation ◽  
Stimulus Onset ◽  
Simple Reaction ◽  
Point Of Subjective Simultaneity ◽  
Subjective Simultaneity ◽  
The Subject

Point of subjective simultaneity and simple reaction time were compared for stimuli with different rise times. It was found that these measures behave differently. To explain the result it is suggested that in the case of temporal-order judgment the subject takes into account not only the stimulus onset but also other events connected with stimulus presentation.

scholarly journals The rapid emergence of auditory object representations in cortex reflect central acoustic attributes

2019 ◽  
Author(s):  
Mattson Ogg ◽  
Thomas A. Carlson ◽  
L. Robert Slevc
Keyword(s):  
Time Course ◽  
Music Perception ◽  
Brain Activity ◽  
Auditory Pathway ◽  
Stimulus Onset ◽  
Object Representations ◽  
Human Environment ◽  
Require Time ◽  
Acoustic Information ◽  
Auditory Object

Human listeners are bombarded by acoustic information that the brain rapidly organizes into coherent percepts of objects and events in the environment, which aids speech and music perception. The efficiency of auditory object recognition belies the critical constraint that acoustic stimuli necessarily require time to unfold. Using magentoencephalography (MEG), we studied the time course of the neural processes that transform dynamic acoustic information into auditory object representations. Participants listened to a diverse set of 36 tokens comprising everyday sounds from a typical human environment. Multivariate pattern analysis was used to decode the sound tokens from the MEG recordings. We show that sound tokens can be decoded from brain activity beginning 90 milliseconds after stimulus onset with peak decoding performance occurring at 155 milliseconds post stimulus onset. Decoding performance was primarily driven by differences between category representations (e.g., environmental vs. instrument sounds), although within-category decoding was better than chance. Representational similarity analysis revealed that these emerging neural representations were related to harmonic and spectrotemporal differences among the stimuli, which correspond to canonical acoustic features processed by the auditory pathway. Our findings begin to link the processing of physical sound properties with the perception of auditory objects and events in cortex.

scholarly journals The Efficacy of Single-Trial Multisensory Memories

2013 ◽  
Vol 26 (5) ◽  
pp. 483-502 ◽  
Author(s):  
Antonia Thelen ◽  
Micah M. Murray
Keyword(s):  
Object Recognition ◽  
Brain Activity ◽  
Memory Performance ◽  
Stimulus Onset ◽  
Object Representations ◽  
Single Trial ◽  
Multisensory Interactions ◽  
Early Processing ◽  
Opposing Effects ◽  
Task Irrelevant

This review article summarizes evidence that multisensory experiences at one point in time have long-lasting effects on subsequent unisensory visual and auditory object recognition. The efficacy of single-trial exposure to task-irrelevant multisensory events is its ability to modulate memory performance and brain activity to unisensory components of these events presented later in time. Object recognition (either visual or auditory) is enhanced if the initial multisensory experience had been semantically congruent and can be impaired if this multisensory pairing was either semantically incongruent or entailed meaningless information in the task-irrelevant modality, when compared to objects encountered exclusively in a unisensory context. Processes active during encoding cannot straightforwardly explain these effects; performance on all initial presentations was indistinguishable despite leading to opposing effects with stimulus repetitions. Brain responses to unisensory stimulus repetitions differ during early processing stages (∼100 ms post-stimulus onset) according to whether or not they had been initially paired in a multisensory context. Plus, the network exhibiting differential responses varies according to whether or not memory performance is enhanced or impaired. The collective findings we review indicate that multisensory associations formedviasingle-trial learning exert influences on later unisensory processing to promote distinct object representations that manifest as differentiable brain networks whose activity is correlated with memory performance. These influences occur incidentally, despite many intervening stimuli, and are distinguishable from the encoding/learning processes during the formation of the multisensory associations. The consequences of multisensory interactions thus persist over time to impact memory retrieval and object discrimination.

Interruption of Late Visual Processing Causes an Attentional Blink

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 134-134
Author(s):  
A Ehrenstein ◽  
B G Breitmeyer ◽  
K K Pritchard ◽  
M Hiscock ◽  
J Crisan
Keyword(s):  
Attentional Blink ◽  
Rapid Serial Visual Presentation ◽  
Visual Processing ◽  
Visual Presentation ◽  
Masking Effect ◽  
Backward Masking ◽  
Spatially Distributed ◽  
Display Location

When the task is to detect two letter targets in a stream of non-letter (digit) distractors in rapid serial visual presentation, an attentional blink (AB; ie a deficit in the detection of a second target when it follows the first by approximately 100 – 500 ms) is often found to occur. In a series of four experiments with different numbers of display positions, with or without masking, we show that: (1) the AB, which occurs when all items are presented at the same display location, is reduced when targets and distractors are presented randomly dispersed over 4 or 9 adjacent locations; (2) the AB is reduced with the spatially distributed presentation even when backward masks are used in all possible stimulus locations and when the location of the next item in the sequence is predictable; (3) the AB is not due to either a location-specific forward or backward masking effect occurring at early levels in visual processing. We conclude that the AB is primarily a function of the interruption of late visual processing produced when the item following the first target occurs at the same location. It seems that, in order for the AB to occur, the item following the first target must be presented at the same location as that target so that it can serve both as a distractor and as a mask interrupting or interfering with late visual processing.

scholarly journals Stable readout of observed actions from format-dependent activity of monkey’s anterior intraparietal neurons

2020 ◽  
Vol 117 (28) ◽  
pp. 16596-16605 ◽  
Author(s):  
Marco Lanzilotto ◽  
Monica Maranesi ◽  
Alessandro Livi ◽  
Carolina Giulia Ferroni ◽  
Guy A. Orban ◽  
...  
Keyword(s):  
Stimulus Presentation ◽  
Visual Presentation ◽  
Brain Regions ◽  
Visual Features ◽  
Large Network ◽  
Population Code ◽  
Dynamic Changes ◽  
Body Postures ◽  
Dependent Activity ◽  
Presentation Formats

Humans accurately identify observed actions despite large dynamic changes in their retinal images and a variety of visual presentation formats. A large network of brain regions in primates participates in the processing of others’ actions, with the anterior intraparietal area (AIP) playing a major role in routing information about observed manipulative actions (OMAs) to the other nodes of the network. This study investigated whether the AIP also contributes to invariant coding of OMAs across different visual formats. We recorded AIP neuronal activity from two macaques while they observed videos portraying seven manipulative actions (drag, drop, grasp, push, roll, rotate, squeeze) in four visual formats. Each format resulted from the combination of two actor’s body postures (standing, sitting) and two viewpoints (lateral, frontal). Out of 297 recorded units, 38% were OMA-selective in at least one format. Robust population code for viewpoint and actor’s body posture emerged shortly after stimulus presentation, followed by OMA selectivity. Although we found no fully invariant OMA-selective neuron, we discovered a population code that allowed us to classify action exemplars irrespective of the visual format. This code depends on a multiplicative mixing of signals about OMA identity and visual format, particularly evidenced by a set of units maintaining a relatively stable OMA selectivity across formats despite considerable rescaling of their firing rate depending on the visual specificities of each format. These findings suggest that the AIP integrates format-dependent information and the visual features of others’ actions, leading to a stable readout of observed manipulative action identity.

scholarly journals The Rapid Emergence of Auditory Object Representations in Cortex Reflect Central Acoustic Attributes

2020 ◽  
Vol 32 (1) ◽  
pp. 111-123 ◽  
Author(s):  
Mattson Ogg ◽  
Thomas A. Carlson ◽  
L. Robert Slevc
Keyword(s):  
Time Course ◽  
Music Perception ◽  
Brain Activity ◽  
Auditory Pathway ◽  
Stimulus Onset ◽  
Object Representations ◽  
Human Environment ◽  
Require Time ◽  
Acoustic Information ◽  
Auditory Object

Human listeners are bombarded by acoustic information that the brain rapidly organizes into coherent percepts of objects and events in the environment, which aids speech and music perception. The efficiency of auditory object recognition belies the critical constraint that acoustic stimuli necessarily require time to unfold. Using magnetoencephalography, we studied the time course of the neural processes that transform dynamic acoustic information into auditory object representations. Participants listened to a diverse set of 36 tokens comprising everyday sounds from a typical human environment. Multivariate pattern analysis was used to decode the sound tokens from the magnetoencephalographic recordings. We show that sound tokens can be decoded from brain activity beginning 90 msec after stimulus onset with peak decoding performance occurring at 155 msec poststimulus onset. Decoding performance was primarily driven by differences between category representations (e.g., environmental vs. instrument sounds), although within-category decoding was better than chance. Representational similarity analysis revealed that these emerging neural representations were related to harmonic and spectrotemporal differences among the stimuli, which correspond to canonical acoustic features processed by the auditory pathway. Our findings begin to link the processing of physical sound properties with the perception of auditory objects and events in cortex.

Effects of Mode of Presentation of Stimulus Materials in Word-Association Tasks

1971 ◽  
Vol 28 (1) ◽  
pp. 211-215
Author(s):  
Richard J. Reynolds ◽  
A. C. Bickley ◽  
Sharon Champion ◽  
Ocie Dekle
Keyword(s):  
Word Association ◽  
Age Groups ◽  
Stimulus Presentation ◽  
Visual Presentation ◽  
Stimulus Modality ◽  
Paradigmatic Shift ◽  
Visual Mode ◽  
Mode Of Presentation ◽  
Stimulus Materials

Differences in paradigmatic response to oral and visual presentation of word-association tasks were compared at 4 age levels ( n = 40). The syntagmatic/paradigmatic shift was investigated as a function of mode of stimulus presentation. Younger Ss produced more paradigmatic responses than older Ss. The oral mode produced more paradigmatic responses than the visual mode for all Ss. The syntagmatic/paradigmatic shift did not occur, nor was the variation across age groups consistent for the two modalities. Evidence indicated that response to. word-association tasks was a function of stimulus modality.

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