Automatic (bottom-up) and Strategic (top-down) Extraction of Facial Features over the N170 Event Related Potential

NeuroImage ◽  
2009 ◽  
Vol 47 ◽  
pp. S134
Author(s):  
LS Frei ◽  
ML Smith ◽  
PG Schyns
Keyword(s):  
Event Related Potential ◽  
Facial Features ◽  
Top Down ◽  
Bottom Up

scholarly journals The bottom-up and top-down processing of faces in the human occipitotemporal cortex

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Xiaoxu Fan ◽  
Fan Wang ◽  
Hanyu Shao ◽  
Peng Zhang ◽  
Sheng He
Keyword(s):  
Facial Features ◽  
Fusiform Face Area ◽  
Functional Magnetic Resonance ◽  
Contextual Cues ◽  
Top Down ◽  
Bottom Up ◽  
Face Area ◽  
Occipital Face Area ◽  
Occipitotemporal Cortex ◽  
The Right

Although face processing has been studied extensively, the dynamics of how face-selective cortical areas are engaged remains unclear. Here, we uncovered the timing of activation in core face-selective regions using functional Magnetic Resonance Imaging and Magnetoencephalography in humans. Processing of normal faces started in the posterior occipital areas and then proceeded to anterior regions. This bottom-up processing sequence was also observed even when internal facial features were misarranged. However, processing of two-tone Mooney faces lacking explicit prototypical facial features engaged top-down projection from the right posterior fusiform face area to right occipital face area. Further, face-specific responses elicited by contextual cues alone emerged simultaneously in the right ventral face-selective regions, suggesting parallel contextual facilitation. Together, our findings chronicle the precise timing of bottom-up, top-down, as well as context-facilitated processing sequences in the occipital-temporal face network, highlighting the importance of the top-down operations especially when faced with incomplete or ambiguous input.

scholarly journals Simulation Study on the Spatiotemporal Difference of Complex Neurodynamics between P3a and P3b

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Xin Wei ◽  
Xiaoli Ni ◽  
Junye Liu ◽  
Haiyang Lang ◽  
Rui Zhao ◽  
...  
Keyword(s):  
Parietal Lobe ◽  
Neural Mechanism ◽  
Brain Regions ◽  
Event Related Potential ◽  
Attention Capture ◽  
Oddball Paradigm ◽  
Top Down ◽  
Bottom Up ◽  
Single Top ◽  
P300 Potentials

The integration of event-related potential (ERP) and functional magnetic resonance imaging (fMRI) helps to obtain and study neural networks with high temporal and spatial resolution. EEG/fMRI data proves that in the visual tristimulus oddball paradigm, two P300 potentials (P3a and P3b) induced by target stimulation and novel stimulation are detected at the frontal-middle (Fz), center (Cz), and mid-apical (Pz) electrodes. Previous studies have shown that P3a and P3b have different spatial distributions of brain activation, but it is unclear whether they have the same neural mechanism. The purpose of this study is to determine the neuropsychological mechanisms of P3a and P3b, as well as the spatiotemporal differences in neurodynamics between the two ERP subcomponents. In a group of 25 subjects, P300 ERP induced by target stimulation and novel stimulation can be detected at the Fz, Cz, and Pz electrodes. At Cz and Fz, compared with P3b related to the target stimulus, the P3a related to the novel stimulus has a higher amplitude and the waveform declines more slowly. But at Pz, P3b has a higher amplitude than P3a. P3a appeared earlier than P3b at Cz and Fz, but the opposite phenomenon was observed at the Pz electrode. The activated brain regions of P3a included the left frontal-parietal lobe region, left anterior wedge lobe region, and right insula, while the target-driven P3b was significantly associated with BOLD changes in the bilateral fusiform gyrus, the left frontal region, and the bilateral insula. The results showed that the integration of the spatial and temporal information of the two imaging modes, namely, ERP and fMRI, proves the existence of the different brain function processes of the two P300 subcomponents. Through the analysis of the composition of P300, the results further proved that the top-down and bottom-up processing processes have played a role in the occurrence of attention capture. It is just that the modulation effects of the two processing mechanisms are different in different tasks. Therefore, it should be noted that the captured neural mechanism is not a single top-down or bottom-up processing process but should be the result of the interaction between the two.

scholarly journals Sensory Processing in Adult ADHD – A Systematic Review

2020 ◽  
Author(s):  
Marcel Schulze ◽  
Silke Lux ◽  
Alexandra Philipsen
Keyword(s):  
Systematic Review ◽  
Sensory Processing ◽  
Adult Adhd ◽  
Event Related Potential ◽  
Visual Modality ◽  
Auditory Modality ◽  
Main Body ◽  
Top Down ◽  
Bottom Up ◽  
Processing Deficits

Abstract BackgroundThe way we perceive our environment is driven by our sensory nervous system and our attentional resources. Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattention, impulsivity, and hyperactivity. While cognitive and behavior dysfunctions have broadly been investigated, sensory processing has received less scientific attention. It has been shown, that children with ADHD show processing and modulatory deficits in multiple sensory domains, but very few studies examine to what extent these deficits persist in adult life. We conducted a systematic review of studies investigating sensory processing in adult ADHD.Main BodyUsing the keywords ‘ADHD’ and ‘sensory processing’, Web of Science and MEDLINE database were systematically searched for all articles published up to March 2020. 53 studies were included. Mostly, visual and auditory processing are studied, few investigated multisensory audiovisual and somatosensory processing. In summary, adult ADHD is marked by increased sensory gaining and deficient sensory inhibition. These disturbed gaining and inhibitory mechanisms were most prominent in the auditory modality but also visual modality impairment in terms of stimuli modulation were evident. Electrophysiological studies show alterations across all event-related potential (ERP) components associated with distractibility at early components (bottom-up) and inhibition and stimulus discrimination at later components (top-down). Brain imaging studies on sensory processing in ADHD are scarce, few pointing to higher resting state functional connectivity in visual areas and visual crossmodal activation for auditory stimuli. ConclusionSensory processing deficits extent from childhood to adult ADHD. These deficits are mainly driven by higher distractibility by irrelevant stimuli and modulatory impairment for relevant stimuli. In future studies, the relation of impaired bottom-up and top-down attentional mechanisms should be investigated and how they contribute to sensory processing deficits and clinical symptomatology in adult ADHD. This could help to gather more information about the underling processing deficits, so that specific adjusted training can be provided, that helps to overcome deficits in daily life functioning in e.g., not producing appropriate adaptive responses in social settings.Trial registrationN/A

Psychology and Culture: Top Down Versus Bottom Up?

PsycCRITIQUES ◽  
2005 ◽  
Vol 50 (19) ◽  
Author(s):  
Michael Cole
Keyword(s):  
Top Down ◽  
Bottom Up

Optimalisasi Ekonomi Syariah Untuk Peningkatan Kesejahteraan Masyarakat Dalam Pengentasan Kemiskinan Mewujudkan Goodgovernance

2019 ◽  
Vol 4 (1) ◽  
pp. 19
Author(s):  
Sadari Sadari ◽  
Nurhidayat Nurhidayat ◽  
Rafiqah Rafiqah
Keyword(s):  
Top Down ◽  
Bottom Up

Humanisme religius telah mengantarkan pada era kesadaran bahwa peradaban manusia harus memiliki dua arus yang saling menunjang. Selama ini arus balik dalam bidang ekonomi hanya menonjolkan arus balik vertikal atas kebawah (model top down) yang didominasi oleh sistem ekonomi kapitalis dan sosialis, sedangkan di sisi lain mengesampingkan arus balik vertikal dari bawah ke atas (model bottom up) yang didominasi oleh sistem ekonomi syariah, sehingga dampaknya adalah adanya kesenjangan ekonomi yang sangat tajam. Paper ini mewujudkan peran penting, yakni menghubungkan dua arus tersebut secara timbal-balik, yakni mempertemukan arus pertama dengan arus balik kedua, sehingga akan menghasilkan dampak yang positif, progresif, kreatif dan produktif, kemudian pada akhirnya akan dapat meng-optomal-kan ekonomi syariah untuk menciptakan goodgovernance, post goodgovernance secara berkelanjutan, tentunya dengan bantuan peran media kontemporer yang kian update. Ekonomi syariah juga merupakan pilar dan nilai dasar, dari sikap keyakinan dan sikap rasionalitas untuk sanggup menciptakan terwujudnya pemberdayaan dan kesejahteraan sekaligus pengentasan kemiskinan dalam masyarakat di Indonesia.

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