scholarly journals The Dorsal Attention Network Reflects Both Encoding Load and Top–down Control during Working Memory

2018 ◽  
Vol 30 (2) ◽  
pp. 144-159 ◽  
Author(s):  
Steve Majerus ◽  
Frédéric Péters ◽  
Marion Bouffier ◽  
Nelson Cowan ◽  
Christophe Phillips
Keyword(s):  
Working Memory ◽  
Recognition Task ◽  
Top Down ◽  
Sensory Stimuli ◽  
Attention Network ◽  
Large Sets ◽  
Dorsal Attention Network ◽  
Memory Control ◽  
And Control

The dorsal attention network is consistently involved in verbal and visual working memory (WM) tasks and has been associated with task-related, top–down control of attention. At the same time, WM capacity has been shown to depend on the amount of information that can be encoded in the focus of attention independently of top–down strategic control. We examined the role of the dorsal attention network in encoding load and top–down memory control during WM by manipulating encoding load and memory control requirements during a short-term probe recognition task for sequences of auditory (digits, letters) or visual (lines, unfamiliar faces) stimuli. Encoding load was manipulated by presenting sequences with small or large sets of memoranda while maintaining the amount of sensory stimuli constant. Top–down control was manipulated by instructing participants to passively maintain all stimuli or to selectively maintain stimuli from a predefined category. By using ROI and searchlight multivariate analysis strategies, we observed that the dorsal attention network encoded information for both load and control conditions in verbal and visuospatial modalities. Decoding of load conditions was in addition observed in modality-specific sensory cortices. These results highlight the complexity of the role of the dorsal attention network in WM by showing that this network supports both quantitative and qualitative aspects of attention during WM encoding, and this is in a partially modality-specific manner.

scholarly journals New insights on the ventral attention network: Active suppression and involuntary recruitment during a bimodal task

2019 ◽  
Author(s):  
Rodolfo Solís-Vivanco ◽  
Ole Jensen ◽  
Mathilde Bonnefond
Keyword(s):  
Attentional Capture ◽  
Frequency Band ◽  
Daily Life ◽  
Sensory Modality ◽  
Top Down ◽  
Unexpected Events ◽  
Attention Network ◽  
Dorsal Attention Network ◽  
Alpha Beta

ABSTRACTReorienting attention to unexpected events is essential in daily life. fMRI studies have revealed the involvement of the ventral attention network (VAN), including the temporo-parietal junction (TPJ), in such process. In this MEG study with 34 participants (17 women) we used a bimodal (visual/auditory) attention task to determine the neuronal dynamics associated with suppression of the activity of the VAN during top-down attention and its recruitment when information from the unattended sensory modality is involuntarily integrated. We observed an anticipatory power increase of alpha/beta (12-20 Hz) oscillations in the VAN following a cue indicating the modality to attend. Stronger VAN power increases predicted better task performance, suggesting that the VAN suppression prevents shifting attention to distractors. Moreover, the TPJ was synchronized with the frontal eye field in that frequency band, suggesting that the dorsal attention network (DAN) might participate in such suppression. Furthermore, we found a 12-20 Hz power decrease, in both the VAN and DAN, when information of both sensory modalities was congruent, suggesting an involvement of these networks for attention capture. Our results show that effective multimodal attentional reorientation includes the modulation of the VAN and DAN through upper-alpha/beta oscillations. Altogether these results indicate that the suppressing role of alpha/beta oscillations might operate beyond sensory regions.SIGNIFICANCE STATEMENTReorienting attention to unexpected events from multiple sensory sources is essential in daily life. We explored the dynamics of the ventral attention network (VAN), a set of brain regions related to attentional reorienting, when relevant information was anticipated (i.e. during top-down attention) and when unexpected congruent information from another sensory modality was presented (involuntary attentional capture). We report that activity in the alpha/beta range (12-20 Hz) within the VAN indexed both top-down and attentional capture processes. Also, the VAN was synchronized with the dorsal attention network in this frequency band, suggesting an integrated role of both networks for attentional regulation. Our results shed light on the neurophysiological mechanisms that the brain carry out for reorienting attention to relevant environmental stimuli.

scholarly journals Temporal circuit of macroscale dynamic brain activity supports human consciousness

2020 ◽  
Vol 6 (11) ◽  
pp. eaaz0087 ◽  
Author(s):  
Zirui Huang ◽  
Jun Zhang ◽  
Jinsong Wu ◽  
George A. Mashour ◽  
Anthony G. Hudetz
Keyword(s):  
Default Mode Network ◽  
Functional Role ◽  
Brain Activity ◽  
Human Consciousness ◽  
Attention Network ◽  
Attention Networks ◽  
Default Mode ◽  
Dorsal Attention Network ◽  
Brain States

The ongoing stream of human consciousness relies on two distinct cortical systems, the default mode network and the dorsal attention network, which alternate their activity in an anticorrelated manner. We examined how the two systems are regulated in the conscious brain and how they are disrupted when consciousness is diminished. We provide evidence for a “temporal circuit” characterized by a set of trajectories along which dynamic brain activity occurs. We demonstrate that the transitions between default mode and dorsal attention networks are embedded in this temporal circuit, in which a balanced reciprocal accessibility of brain states is characteristic of consciousness. Conversely, isolation of the default mode and dorsal attention networks from the temporal circuit is associated with unresponsiveness of diverse etiologies. These findings advance the foundational understanding of the functional role of anticorrelated systems in consciousness.

Conditionality and Homelessness Services; ‘Practice Realities’ in a Drop-in Centre

2011 ◽  
Vol 10 (4) ◽  
pp. 547-557 ◽  
Author(s):  
Rachael Dobson
Keyword(s):  
Study Analysis ◽  
Front Line ◽  
Top Down ◽  
Bottom Up ◽  
Case Study Analysis ◽  
Support Practices ◽  
And Control ◽  
Policies And Practices

This article provides insights into the client−practitioner interaction, as understood through the eyes of those working at the front-line in a Drop-in Centre for homeless clients. Through a case-study analysis of ‘official’ techniques and informal approaches, it is argued that conditional practices are present in contemporary support practices. However, the picture is fragmented, with practitioners arguing for, but also deviating from, conditional strategies that aspire to shape client behaviour. Choices about appropriate responses are occasionally permeated by ‘top−down’ policy messages that aim to responsibilise and generate change in clients. However there is evidence of ‘bottom−up’ drivers informed by experiences of working with clients at the grassroots. These ‘practice realities’ shift an analysis of conditional tactics from just a moralising and disciplining approach, and suggest a more complex set of events at the front-line. Insights add to ongoing commentary about an apparent policy emphasis on rectifying the behaviour of citizens at the sharp end. Conclusions highlight the role of complexity for understanding therapeutic and disciplining elements in policies and practices. Such debates are especially relevant where they connect to the care and control of individuals understood by practitioners as both transgressive and vulnerable.

scholarly journals Top-Down Modulation of Auditory-Motor Integration during Speech Production: The Role of Working Memory

2017 ◽  
Vol 37 (43) ◽  
pp. 10323-10333 ◽  
Author(s):  
Zhiqiang Guo ◽  
Xiuqin Wu ◽  
Weifeng Li ◽  
Jeffery A. Jones ◽  
Nan Yan ◽  
...  
Keyword(s):  
Working Memory ◽  
Speech Production ◽  
Top Down

scholarly journals Gestalts at threshold could reveal Gestalts as predictions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Thiago Leiros Costa ◽  
Johan Wagemans
Keyword(s):  
Predictive Processing ◽  
Top Down ◽  
Visual Neurons ◽  
Chance Performance ◽  
Response Profile ◽  
Early Visual Cortex ◽  
Feedback Connections ◽  
And Control ◽  
Contrast Response

AbstractWe review and revisit the predictive processing inspired “Gestalts as predictions” hypothesis. The study of Gestalt phenomena at and below threshold can help clarify the role of higher-order object selective areas and feedback connections in mid-level vision. In two psychophysical experiments assessing manipulations of contrast and configurality we showed that: (1) Gestalt phenomena are robust against saliency manipulations across the psychometric function even below threshold (with the accuracy gains and higher saliency associated with Gestalts being present even around chance performance); and (2) peak differences between Gestalt and control conditions happened around the time where responses to Gestalts are starting to saturate (mimicking the differential contrast response profile of striate vs. extra-striate visual neurons). In addition, Gestalts are associated with steeper psychometric functions in all experiments. We propose that these results reflect the differential engagement of object-selective areas in Gestalt phenomena and of information- or percept-based processing, as opposed to energy- or stimulus-based processing, more generally. In addition, the presence of nonlinearities in the psychometric functions suggest differential top-down modulation of the early visual cortex. We treat this as a proof of principle study, illustrating that classic psychophysics can help assess possible involvement of hierarchical predictive processing in Gestalt phenomena.

scholarly journals Role of the dorsal attention network in distracter suppression based on features

2019 ◽  
Vol 11 (1-2) ◽  
pp. 37-46 ◽  
Author(s):  
Armien Lanssens ◽  
Gloria Pizzamiglio ◽  
Dante Mantini ◽  
Celine R. Gillebert
Keyword(s):  
Attention Network ◽  
Dorsal Attention Network

Interaction of the Salience Network, Ventral Attention Network, Dorsal Attention Network and Default Mode Network in Neonates and Early Development of the Bottom-up Attention System.

2021 ◽  
Author(s):  
Valeria Onofrj ◽  
Antonio Maria Chiarelli ◽  
Richard Wise ◽  
Cesare Colosimo ◽  
Massimo Caulo
Keyword(s):  
Functional Connectivity ◽  
Default Mode Network ◽  
Mediation Analysis ◽  
Data Driven ◽  
Salience Network ◽  
Bottom Up ◽  
Attention Network ◽  
Default Mode ◽  
Dorsal Attention Network

Abstract The Salience Network (SN), Ventral Attention Network (VAN), Dorsal Attention Network (DAN) and Default Mode Network (DMN) have shown significant interactions and overlapping functions in bottom-up and top-down mechanisms of attention. In the present study we tested if the SN, VAN, DAN and DMN connectivity can infer the gestational age (GA) at birth in a study group of 88 healthy neonates with GA at birth ranging from 28 to 40 weeks. We also ascertained whether the connectivity within each of the SN, VAN, DAN and DMN is able to infer the average functional connectivity of the others. The ability to infer GA at birth or another network's connectivity was evaluated using a multi-variate data-driven framework. A mediation analysis was performed in order to estimate the transmittance of change of a network’s functional connectivity (FC) over another mediated by the GA.The VAN, DAN and the DMN infer the GA at birth (p<0.05). The SN, DMN and VAN were able to infer the average connectivity over the other networks (p<0.05). Mediation analysis between VAN’s and DAN’s inference on GA found reciprocal transmittance of change of VAN’s and DAN’s connectivity (p<0.05). Our findings suggest that the VAN has a prominent role in the bottom-up salience detection in early infancy and that the role of the VAN and the SN may overlap in the bottom-up control of attention.

The prevalence of visual hallucinations in non-affective psychosis, and the role of perception and attention

2016 ◽  
Vol 46 (8) ◽  
pp. 1735-1747 ◽  
Author(s):  
M. M. van Ommen ◽  
M. van Beilen ◽  
F. W. Cornelissen ◽  
H. G. O. M. Smid ◽  
H. Knegtering ◽  
...  
Keyword(s):  
Visual Perception ◽  
Performance Test ◽  
Recognition Task ◽  
Continuous Performance Test ◽  
Visual Hallucinations ◽  
Top Down ◽  
Affective Psychosis ◽  
Bottom Up ◽  
Patient Groups

BackgroundLittle is known about visual hallucinations (VH) in psychosis. We investigated the prevalence and the role of bottom-up and top-down processing in VH. The prevailing view is that VH are probably related to altered top-down processing, rather than to distorted bottom-up processing. Conversely, VH in Parkinson's disease are associated with impaired visual perception and attention, as proposed by the Perception and Attention Deficit (PAD) model. Auditory hallucinations (AH) in psychosis, however, are thought to be related to increased attention.MethodOur retrospective database study included 1119 patients with non-affective psychosis and 586 controls. The Community Assessment of Psychic Experiences established the VH rate. Scores on visual perception tests [Degraded Facial Affect Recognition (DFAR), Benton Facial Recognition Task] and attention tests [Response Set-shifting Task, Continuous Performance Test-HQ (CPT-HQ)] were compared between 75 VH patients, 706 non-VH patients and 485 non-VH controls.ResultsThe lifetime VH rate was 37%. The patient groups performed similarly on cognitive tasks; both groups showed worse perception (DFAR) than controls. Non-VH patients showed worse attention (CPT-HQ) than controls, whereas VH patients did not perform differently.ConclusionsWe did not find significant VH-related impairments in bottom-up processing or direct top-down alterations. However, the results suggest a relatively spared attentional performance in VH patients, whereas face perception and processing speed were equally impaired in both patient groups relative to controls. This would match better with the increased attention hypothesis than with the PAD model. Our finding that VH frequently co-occur with AH may support an increased attention-induced ‘hallucination proneness’.

Temporal Characteristics of Top-Down Modulations during Working Memory Maintenance: An Event-related Potential Study of the N170 Component

2007 ◽  
Vol 19 (11) ◽  
pp. 1836-1844 ◽  
Author(s):  
Kartik K. Sreenivasan ◽  
Jennifer Katz ◽  
Amishi P. Jha
Keyword(s):  
Working Memory ◽  
Recognition Task ◽  
Event Related Potential ◽  
Perceptual Processing ◽  
Top Down ◽  
Domain Specific ◽  
N170 Component ◽  
Delay Duration ◽  
The Face ◽  
Delayed Recognition

We investigated the top-down influence of working memory (WM) maintenance on feedforward perceptual processing within occipito-temporal face processing structures. During event-related potential (ERP) recordings, subjects performed a delayed-recognition task requiring WM maintenance of faces or houses. The face-sensitive N170 component elicited by delay-spanning task-irrelevant grayscale noise probes was examined. If early feedforward perceptual activity is biased by maintenance requirements, the N170 ERP component elicited by probes should have a greater N170 amplitude response during face relative to house WM trials. Consistent with this prediction, N170 elicited by probes presented at the beginning, middle, and end of the delay interval was greater in amplitude during face relative to house WM. Thus, these results suggest that WM maintenance demands may modulate early feedforward perceptual processing for the entirety of the delay duration. We argue based on these results that temporally early biasing of domain-specific perceptual processing may be a critical mechanism by which WM maintenance is achieved.

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