scholarly journals Scene complexity modulates degree of feedback activity during object recognition in natural scenes

2018 ◽  
Author(s):  
Iris I. A. Groen ◽  
Sara Jahfari ◽  
Noor Seijdel ◽  
Sennary Ghebreab ◽  
Victor A. F. Lamme ◽  
...  
Keyword(s):  
Object Recognition ◽  
Event Related Potentials ◽  
Natural Scenes ◽  
High Complexity ◽  
Perceptual Decision Making ◽  
Feed Forward ◽  
Complex Scenes ◽  
Related Potentials ◽  
Neural Feedback ◽  
The Brain

AbstractObject recognition is thought to be mediated by rapid feed-forward activation of object-selective cortex, with limited contribution of feedback. However, disruption of visual evoked activity beyond feed-forward processing stages has been demonstrated to affect object recognition performance. Here, we unite these findings by reporting that the detection of target objects in natural scenes is selectively characterized by enhanced feedback when these objects are embedded in high complexity scenes. Human participants performed an animal target detection task on scenes with low, medium or high complexity as determined by a biologically plausible computational model of low-level contrast statistics. Three converging lines of evidence indicate that feedback was enhanced during categorization of scenes with high, but not low or medium complexity. First, functional magnetic resonance imaging (fMRI) activity in early visual cortex (V1) was selectively enhanced for target objects in scenes with high complexity. Second, event-related potentials (ERPs) evoked by high complexity scenes were selectively enhanced from 220 ms after stimulus-onset. Third, behavioral performance deteriorated for highly complex scenes when participants were pressed for time, but not when they could process the scenes fully and thereby benefit from the enhanced feedback. Formal modeling of the reaction time distributions revealed that object information accumulated more slowly for high complexity scenes (resulting in more errors especially for fast decisions), and directly related to the build-up of the feedback activity that was observed exclusively for high complexity scenes. Together, these results suggest that while feed-forward activity may suffice for simple scenes, the brain employs recurrent processing more adaptively in naturalistic settings, using minimal feedback for sparse, coherent scenes and increasing feedback for complex, fragmented scenes.Author summaryHow much neural processing is required to detect objects of interest in natural scenes? The astonishing speed of object recognition suggests that fast feed-forward buildup of perceptual activity is sufficient. However, this view is contradicted by findings that show that disruption of slower neural feedback leads to decreased detection performance. Our study unites these discrepancies by identifying scene complexity as a critical driver of neural feedback. We show how feedback is enhanced for complex, cluttered scenes compared to simple, well-organized scenes. Moreover, for complex scenes, more feedback is associated with better performances. These findings relate the flexibility of neural processes to perceptual decision-making by demonstrating that the brain dynamically directs neural resources based on the complexity of real-world visual inputs.

scholarly journals Induced Gamma-band Activity Elicited by Visual Representation of Unattended Objects

2009 ◽  
Vol 21 (1) ◽  
pp. 42-57 ◽  
Author(s):  
Jasna Martinovic ◽  
Thomas Gruber ◽  
Kathrin Ohla ◽  
Matthias M. Müller
Keyword(s):  
Object Recognition ◽  
Perceptual Load ◽  
Visual Representation ◽  
Event Related Potentials ◽  
Attentional Focus ◽  
Gamma Band ◽  
Complex Scenes ◽  
Related Potentials ◽  
Gamma Band Activity ◽  
Band Activity

Object recognition is achieved through neural mechanisms reliant on the activity of distributed neural assemblies that are thought to be coordinated by synchronous firing in the gamma-band range (>20 Hz). An outstanding question focuses on the extent to which the role of gamma oscillations in object recognition is dependent on attention. Attentional mechanisms determine the allocation of perceptual resources to objects in complex scenes biasing the outcome of their mutual competitive interactions. Would object-related enhancements in gamma activity also occur for unattended objects when perceptual resources are traded off to the processing of concurrent visual material? The present electroencephalogram study investigated event-related potentials and evoked (time- and phase-locked) and induced (non-time- and phase-locked to stimulus onset) gamma-band activity (GBA) using a visual discrimination task of low or high perceptual load at fixation. The task was performed while task-irrelevant familiar or unfamiliar objects coappeared in the surrounding central area. Attentional focus was kept at fixation by varying perceptual load between trials; in such conditions, only holistic object processing or low-level perceptual processing, requiring little or no attention, are thought to occur. Although evoked GBA remained unmodulated, induced GBA enhancements, specific to familiar object presentations, were observed, thus providing evidence for cortical visual representation of unattended objects. In addition, the effect was mostly driven by object-specific activity under low load, implying that, in cluttered or complex scenes, attentional selection likely plays a more significant role in object representation.

Bringing the brain into personality assessment: Is there a place for event-related potentials?

2019 ◽  
Vol 31 (4) ◽  
pp. 488-501 ◽  
Author(s):  
Takakuni Suzuki ◽  
Kaylin E. Hill ◽  
Belel Ait Oumeziane ◽  
Dan Foti ◽  
Douglas B. Samuel
Keyword(s):  
Personality Assessment ◽  
Event Related Potentials ◽  
Related Potentials ◽  
The Brain

Event-Related Potentials in Psychiatry: Approaches to Research and Clinical Applications

1983 ◽  
Vol 17 (4) ◽  
pp. 307-318 ◽  
Author(s):  
H. G. Stampfer
Keyword(s):  
Information Processing ◽  
Psychiatric Disorders ◽  
Rapid Development ◽  
Event Related Potentials ◽  
Clinical Applications ◽  
Direct Access ◽  
Practical Application ◽  
Clinical Methods ◽  
Related Potentials ◽  
The Brain

This article suggests that the potential usefulness of event-related potentials in psychiatry has not been fully explored because of the limitations of various approaches to research adopted to date, and because the field is still undergoing rapid development. Newer approaches to data acquisition and methods of analysis, combined with closer co-operation between medical and physical scientists, will help to establish the practical application of these signals in psychiatric disorders and assist our understanding of psychophysiological information processing in the brain. Finally, it is suggested that psychiatrists should seek to understand these techniques and the data they generate, since they provide more direct access to measures of complex cerebral processes than current clinical methods.

Directed and Motivated Attention during Processing of Natural Scenes

2008 ◽  
Vol 20 (10) ◽  
pp. 1753-1761 ◽  
Author(s):  
Vera Ferrari ◽  
Maurizio Codispoti ◽  
Rossella Cardinale ◽  
Margaret M. Bradley
Keyword(s):  
Neural Circuits ◽  
Event Related Potentials ◽  
Natural Scenes ◽  
Directed Attention ◽  
Positive Potential ◽  
New Information ◽  
Motivated Attention ◽  
Related Potentials ◽  
Emotional Pictures ◽  
The Relationship

Visual attention can be voluntarily oriented to detect target stimuli in order to facilitate goal-directed behaviors. Other visual stimuli capture attention because of motivational significance. The aim of the present study was to investigate the relationship between directed and motivated attention using event-related potentials. Affectively engaging pictures were presented either as target stimuli or as nontargets in a categorization task. Results indicated that both task relevance and emotional significance modulated the late positive potential (LPP) over centro-parietal sensors. Effects of directed and motivated attention on the LPP were additive, with the largest centro-parietal positivity found for emotional pictures that were targets of directed attention, and the least for neutral pictures that were nontargets. Taken together, the data provide new information regarding the relationship between motivated and directed attention, and suggest that the LPP reflects the operation of attentional neural circuits that are utilized by both top-down and bottom-up processes.

scholarly journals Monitoring Migraine Cycle Dynamics with an Easy-to-Use Electrophysiological Marker—A Pilot Study

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3918 ◽  
Author(s):  
Goded Shahaf ◽  
Pora Kuperman ◽  
Yuval Bloch ◽  
Shahak Yariv ◽  
Yelena Granovsky
Keyword(s):  
Pilot Study ◽  
Stress Level ◽  
Event Related Potentials ◽  
Healthy Controls ◽  
Preliminary Results ◽  
Auditory Oddball ◽  
Control Subjects ◽  
Related Potentials ◽  
Auditory Oddball Task ◽  
The Brain

Migraine attacks can cause significant discomfort and reduced functioning for days at a time, including the pre-ictal and post-ictal periods. During the inter-ictsal period, however, migraineurs seem to function normally. It is puzzling, therefore, that event-related potentials of migraine patients often differ in the asymptomatic and inter-ictal period. Part of the electrophysiological dynamics demonstrated in the migraine cycle are attention related. In this pilot study we evaluated an easy-to-use new marker, the Brain Engagement Index (BEI), for attention monitoring during the migraine cycle. We sampled 12 migraine patients for 20 days within one calendar month. Each session consisted of subjects’ reports of stress level and migraine-related symptoms, and a 5 min EEG recording, with a 2-electrode EEG device, during an auditory oddball task. The first minute of the EEG sample was analyzed. Repetitive samples were also obtained from 10 healthy controls. The brain engagement index increased significantly during the pre-ictal (p ≈ 0.001) and the ictal (p ≈ 0.020) periods compared with the inter-ictal period. No difference was observed between the pre-ictal and ictal periods. Control subjects demonstrated intermediate Brain Engagement Index values, that is, higher than inter-ictal, yet lower than pre-ictal. Our preliminary results demonstrate the potential advantage of the use of a simple EEG system for improved prediction of migraine attacks. Further study is required to evaluate the efficacy of the Brain Engagement Index in monitoring the migraine cycle and the possible effects of interventions.

scholarly journals Gaming enhances learning-induced plastic changes in the brain

2020 ◽  
Author(s):  
Katja Junttila ◽  
Anna-Riikka Smolander ◽  
Reima Karhila ◽  
Anastasia Giannakopoulou ◽  
Maria Uther ◽  
...  
Keyword(s):  
Language Learning ◽  
Event Related Potentials ◽  
Speech Sounds ◽  
Digital Game ◽  
Game Based Learning ◽  
Brain Response ◽  
Related Potentials ◽  
Plastic Changes ◽  
Game Condition ◽  
The Brain

Learning is increasingly assisted by technology. Digital games may be useful for learning, especially in children. However, more research is needed to understand the factors that induce gaming benefits to cognition. In this study, we investigated the effectiveness of digital game-based learning approach in children by comparing the learning of foreign speech sounds and words in a digital game or a non-game digital application with equal amount of exposure and practice. To evaluate gaming-induced plastic changes in the brain function, we used the mismatch negativity (MMN) brain response that reflects the activation of long-term memory representations for speech sounds and words. We recorded auditory event-related potentials (ERPs) from 37 school-aged Finnish-speaking children before and after playing the “Say it again, kid!” (SIAK) language-learning game where they explored game boards, produced English words aloud, and got stars as feedback from an automatic speech recognizer to proceed in the game. The learning of foreign speech sounds and words was compared in two conditions embedded in the game: a game condition and a non-game condition with the same speech production task but lacking visual game elements and feedback. The MMN amplitude increased between the pre-measurement and the post-measurement for the word trained with the game but not for the word trained with the non-game condition, suggesting that the gaming intervention enhanced learning more than the non-game intervention. The results indicate that digital game-based learning can be beneficial for children’s language learning and that gaming elements per se, not just practise time, support learning.

Source Localization of Subtopographic Brain Maps for Event Related Potentials (ERP)

2008 ◽  
pp. 1247-1252
Author(s):  
Adil Deniz Duru ◽  
Ali Bayram ◽  
Tamer Demiralp ◽  
Ahmet Ademoglu
Keyword(s):  
Source Localization ◽  
Temporal Frequency ◽  
Event Related Potentials ◽  
Functional Brain Imaging ◽  
Frequency Content ◽  
Brain Potentials ◽  
Functional Brain ◽  
Brain Responses ◽  
Related Potentials ◽  
The Brain

Event-related potentials (ERP) are transient brain responses to cognitive stimuli, and they consist of several stationary events whose temporal frequency content can be characterized in terms of oscillations or rhythms. Precise localization of electrical events in the brain, based on the ERP data recorded from the scalp, has been one of the main challenges of functional brain imaging. Several currentDensity estimation techniques for identifying the electrical sources generating the brain potentials are developed for the so-called neuroelectromagnetic inverse problem in the last three decades (Baillet, Mosher, & Leahy, 2001; Koles, 1998; Michela, Murraya, Lantza, Gonzaleza, Spinellib, & Grave de Peraltaa, 2004; Scherg & von Cramon, 1986).

Low-dimensional versus high-dimensional chaos in brain function – is it an and/or issue?

2001 ◽  
Vol 24 (5) ◽  
pp. 823-824 ◽  
Author(s):  
Márk Molnár
Keyword(s):  
Brain Function ◽  
Sensory Information ◽  
Event Related Potentials ◽  
Cognitive Effort ◽  
Neural Systems ◽  
Sensory Information Processing ◽  
Related Potentials ◽  
Dimensional Complexity ◽  
Low Dimensional ◽  
The Brain

We discuss whether low-dimensional chaos and even nonlinear processes can be traced in the electrical activity of the brain. Experimental data show that the dimensional complexity of the EEG decreases during event-related potentials associated with cognitive effort. This probably represents increased nonlinear cooperation between different neural systems during sensory information processing.

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