scholarly journals Human frontoparietal cortex represents behaviorally relevant target status based on abstract object features

2019 ◽  
Vol 121 (4) ◽  
pp. 1410-1427 ◽  
Author(s):  
Margaret Henderson ◽  
John T. Serences
Keyword(s):  
Frontal Cortex ◽  
Functional Mri ◽  
Irrelevant Dimension ◽  
Target Recognition ◽  
Human Subjects ◽  
Object Identity ◽  
Neural Basis ◽  
Related Information ◽  
Parking Lot ◽  
High Level

Searching for items that are useful given current goals, or “target” recognition, requires observers to flexibly attend to certain object properties at the expense of others. This could involve focusing on the identity of an object while ignoring identity-preserving transformations such as changes in viewpoint or focusing on its current viewpoint while ignoring its identity. To effectively filter out variation due to the irrelevant dimension, performing either type of task is likely to require high-level, abstract search templates. Past work has found target recognition signals in areas of ventral visual cortex and in subregions of parietal and frontal cortex. However, target status in these tasks is typically associated with the identity of an object, rather than identity-orthogonal properties such as object viewpoint. In this study, we used a task that required subjects to identify novel object stimuli as targets according to either identity or viewpoint, each of which was not predictable from low-level properties such as shape. We performed functional MRI in human subjects of both sexes and measured the strength of target-match signals in areas of visual, parietal, and frontal cortex. Our multivariate analyses suggest that the multiple-demand (MD) network, including subregions of parietal and frontal cortex, encodes information about an object’s status as a target in the relevant dimension only, across changes in the irrelevant dimension. Furthermore, there was more target-related information in MD regions on correct compared with incorrect trials, suggesting a strong link between MD target signals and behavior. NEW & NOTEWORTHY Real-world target detection tasks, such as searching for a car in a crowded parking lot, require both flexibility and abstraction. We investigated the neural basis of these abilities using a task that required invariant representations of either object identity or viewpoint. Multivariate decoding analyses of our whole brain functional MRI data reveal that invariant target representations are most pronounced in frontal and parietal regions, and the strength of these representations is associated with behavioral performance.

scholarly journals Flexible recruitment of memory-based choice representations by human medial-frontal cortex

2019 ◽  
Author(s):  
Juri Minxha ◽  
Ralph Adolphs ◽  
Stefano Fusi ◽  
Adam N. Mamelak ◽  
Ueli Rutishauser
Keyword(s):  
Frontal Cortex ◽  
Memory Retrieval ◽  
Medial Temporal Lobe ◽  
Human Subjects ◽  
Phase Locking ◽  
Task Demands ◽  
Medial Frontal Cortex ◽  
Button Press ◽  
Perceptual Decision Making ◽  
Related Information

SummaryDecisions in complex environments rely on flexibly utilizing past experience as required by context and instructions1. This process depends on the medial frontal cortex (MFC) and the medial temporal lobe (MTL)2-5, but it remains unknown how these structures jointly implement flexible memory retrieval6,7. We recorded single neurons in MFC and MTL while human subjects switched8 between making memory- and categorization-based decisions9,10. Here we show that MFC rapidly implements changing task demands by utilizing different subspaces of neural activity during different types of decisions. In contrast, no effect of task demands was seen in the MTL. Choices requiring memory retrieval selectively engaged phase-locking of MFC neurons to field potentials in the theta-frequency band in the MTL. Choice-selective neurons in MFC signaled abstract yes-no decisions independent of behavioral response modality (button press or saccade). These findings reveal a novel mechanism for flexibly and selectively engaging memory retrieval11-14 and show that unlike perceptual decision-making15, memory-related information is only represented in frontal cortex when choices require it.

Specialized systems for the processing of mnemonic information within the primate frontal cortex

1996 ◽  
Vol 351 (1346) ◽  
pp. 1455-1462 ◽  
Keyword(s):  
Frontal Cortex ◽  
Specific Activity ◽  
Human Subjects ◽  
Long Term Memory ◽  
Executive Processing ◽  
Severe Impairment ◽  
Normal Human ◽  
Short And Long Term ◽  
Cortical Association Areas

The lateral frontal cortex is involved in various aspects of executive processing within short- and long-term memory. It is argued that the different parts of the lateral frontal cortex make distinct contributions to memory that differ in terms of the level of executive processing that is carried out in interaction with posterior cortical systems. According to this hypothesis, the mid-dorsolateral frontal cortex (areas 46 and 9) is a specialized system for the monitoring and manipulation of information within working memory, whereas the mid-ventrolateral frontal cortex (areas 47/12 and 45) is involved in the active retrieval of information from the posterior cortical association areas. Data are presented which support this two-level hypothesis that posits two distinct levels of interaction of the lateral frontal cortex with posterior cortical association areas. Functional activation studies with normal human subjects have demonstrated specific activity within the mid-dorsolateral region of the frontal cortex during the performance of tasks requiring monitoring of self-generated and externally generated sequences of responses. In the monkey, lesions restricted to this region of the frontal cortex yield a severe impairment in performance of the above tasks, this impairment appearing against a background of normal performance on several basic mnemonic tasks. By contrast, a more severe impairment follows damage to the mid-ventrolateral frontal region and functional activation studies have demonstrated specific changes in activity in this region in relation to the active retrieval of information from memory.

scholarly journals Automatic Target Recognition for Low Resolution Foliage Penetrating SAR Images Using CNNs and GANs

2021 ◽  
Vol 13 (4) ◽  
pp. 596
Author(s):  
David Vint ◽  
Matthew Anderson ◽  
Yuhao Yang ◽  
Christos Ilioudis ◽  
Gaetano Di Caterina ◽  
...  
Keyword(s):  
Target Recognition ◽  
Automatic Target Recognition ◽  
Generative Adversarial Networks ◽  
Low Resolution ◽  
Sar Images ◽  
Adversarial Networks ◽  
Technological Advances ◽  
Dataset Size ◽  
Resolution Imaging ◽  
High Level

In recent years, the technological advances leading to the production of high-resolution Synthetic Aperture Radar (SAR) images has enabled more and more effective target recognition capabilities. However, high spatial resolution is not always achievable, and, for some particular sensing modes, such as Foliage Penetrating Radars, low resolution imaging is often the only option. In this paper, the problem of automatic target recognition in Low Resolution Foliage Penetrating (FOPEN) SAR is addressed through the use of Convolutional Neural Networks (CNNs) able to extract both low and high level features of the imaged targets. Additionally, to address the issue of limited dataset size, Generative Adversarial Networks are used to enlarge the training set. Finally, a Receiver Operating Characteristic (ROC)-based post-classification decision approach is used to reduce classification errors and measure the capability of the classifier to provide a reliable output. The effectiveness of the proposed framework is demonstrated through the use of real SAR FOPEN data.

The Acceptability and Effectiveness of Videos Promoting Smoking Cessation Among Australians Experiencing Mental Illness

2021 ◽  
pp. 109019812110347
Author(s):  
Ratika Sharma-Kumar ◽  
Cheneal Puljević ◽  
Kylie Morphett ◽  
Carla Meurk ◽  
Coral Gartner
Keyword(s):  
Mental Illness ◽  
Smoking Cessation ◽  
Rank Test ◽  
Related Information ◽  
Signed Rank ◽  
Semistructured Interviews ◽  
Promote Smoking Cessation ◽  
Health Related ◽  
Signed Rank Test ◽  
High Level

There are high rates of tobacco smoking among people who experience mental illness (MI). While videos are an effective method of disseminating health-related information, there is limited research investigating the effectiveness of video-delivered education promoting smoking cessation among people living with MI. This formative study aimed to investigate the effectiveness and acceptability of targeted video resources providing smoking cessation information and advice to smokers with MI. This study used a mixed-method design; 29 Australian smokers living with MI completed a preinterview survey including 12 questions assessing knowledge about smoking cessation, watched six videos developed by the research team providing information about smoking cessation, took part in semistructured interviews about the videos’ quality, content, and format, and then completed a postinterview survey identical to the preinterview survey to assess changes in smoking cessation-related knowledge. A Wilcoxon signed rank test was used to calculate changes in cessation-related knowledge, and thematic analysis was used to identify common themes in qualitative data. We found a statistically significant increase in participants’ smoking cessation-related knowledge scores after watching the videos. Participants indicated an overall high level of acceptability of the videos’ quality, content, and format, and findings from the semistructured interviews reflected these favorable views. This study’s findings provide a new understanding of the effectiveness and acceptability of customized video-based education to promote smoking cessation among people living with MI, and can be used to inform the content and focus of video resources aimed at increasing knowledge about smoking cessation for people experiencing MI.

scholarly journals Dynamic and stable brain connectivity during movie watching as revealed by functional MRI

2021 ◽  
Author(s):  
Xin Di ◽  
Zhiguo Zhang ◽  
Ting Xu ◽  
Bharat B. Biswal
Keyword(s):  
Functional Mri ◽  
Brain Connectivity ◽  
Brain Regions ◽  
Posterior Cingulate Cortex ◽  
Temporoparietal Junction ◽  
Related Information ◽  
Movie Clip ◽  
Brain Changes ◽  
Brain Processing ◽  
Dynamic Connectivity

AbstractSpatially remote brain regions show synchronized activity as typically revealed by correlated functional MRI (fMRI) signals. An emerging line of research has focused on the temporal fluctuations of connectivity, however, its relationships with stable connectivity have not been clearly illustrated. We examined the stable and dynamic connectivity from fMRI data when the participants watched four different movie clips. Using inter-individual correlation, we were able to estimate functionally meaningful dynamic connectivity associated with different movies. Widespread consistent dynamic connectivity was observed for each movie clip as well as their differences between clips. A cartoon movie clip showed higher consistent dynamic connectivity with the posterior cingulate cortex and supramarginal gyrus, while a court drama clip showed higher dynamic connectivity with the auditory cortex and temporoparietal junction, which suggest the involvement of specific brain processing for different movie contents. In contrast, stable connectivity was highly similar among the movie clips, and showed fewer statistical significant differences. The patterns of dynamic connectivity had higher accuracy for classifications of different movie clips than the stable connectivity and regional activity. These results support the functional significance of dynamic connectivity in reflecting functional brain changes, which could provide more functionally related information than stable connectivity.

scholarly journals Plasma appearance and correlation between coffee and green tea metabolites in human subjects

2010 ◽  
Vol 104 (11) ◽  
pp. 1635-1640 ◽  
Author(s):  
Mathieu Renouf ◽  
Philippe Guy ◽  
Cynthia Marmet ◽  
Karin Longet ◽  
Anne-Lise Fraering ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Green Tea ◽  
Phenolic Acids ◽  
Human Subjects ◽  
Coffee Consumption ◽  
Maximum Plasma Concentration ◽  
Maximum Plasma ◽  
Isoferulic Acid ◽  
Long Time ◽  
High Level

Coffee and green tea are two of the most widely consumed hot beverages in the world. Their respective bioavailability has been studied separately, but absorption of their respective bioactive phenolics has not been compared. In a randomised cross-over design, nine healthy subjects drank instant coffee and green tea. Blood samples were collected over 12 h and at 24 h to assess return to baseline. After green tea consumption, ( − )-epigallocatechin (EGC) was the major catechin, appearing rapidly in the plasma; ( − )-EGC gallate (EGCg) and ( − )-epicatechin (EC) were also present, but ( − )-EC gallate and C were not detected. Dihydroferulic acid and dihydrocaffeic acid were the major metabolites that appeared after coffee consumption with a long time needed to reach maximum plasma concentration, suggesting metabolism and absorption in the colon. Other phenolic acid equivalents (caffeic acid (CA), ferulic acid (FA) and isoferulic acid (iFA)) were detected earlier, and they peaked at lower concentrations. Summations of the plasma area under the curves (AUC) for the measured metabolites showed 1·7-fold more coffee-derived phenolic acids than green tea-derived catechins (P = 0·0014). Furthermore, we found a significant correlation between coffee metabolites based on AUC. Inter-individual differences were observed, but individuals with a high level of CA also showed a correspondingly high level of FA. However, no such correlation was observed between the tea catechins and coffee phenolic acids. Correlation between AUC and maximum plasma concentration was also significant for CA, FA and iFA and for EGCg. This implies that the mechanisms of absorption for these two classes of compounds are different, and that a high absorber of phenolic acids is not necessarily a high absorber of catechins.

Abnormal High-Level Event Recognition in Parking lot

2018 ◽  
pp. 389-398 ◽  
Author(s):  
Najla Bouarada Ghrab ◽  
Rania Rebai Boukhriss ◽  
Emna Fendri ◽  
Mohamed Hammami
Keyword(s):  
Event Recognition ◽  
Parking Lot ◽  
High Level

Threat Representation Methods for Composite Service Process Models

2013 ◽  
Vol 4 (2) ◽  
pp. 1-18 ◽  
Author(s):  
Per Håkon Meland ◽  
Erlend Andreas Gjære
Keyword(s):  
Business Processes ◽  
Process Models ◽  
Software Systems ◽  
Related Information ◽  
Process Collaboration ◽  
Version 2.0 ◽  
Composite Services ◽  
Technical Specifications ◽  
Business Process Modeling Notation ◽  
High Level

The Business Process Modeling Notation (BPMN) has become a popular standard for expressing high level business processes as well as technical specifications for software systems. However, the specification does not contain native support to express security information, which should not be overlooked in today’s world where every organization is exposed to threats and has assets to protect. Although a substantial amount of work enhancing BPMN 1.x with security related information already exists, the opportunities provided by version 2.0 have not received much attention in the security community so far. This paper gives an overview of security in BPMN and investigates several possibilities of representing threats in BPMN 2.0, in particular for design-time specification and runtime execution of composite services with dynamic behavior. Enriching BPMN with threat information enables a process-centric threat modeling approach that complements risk assessment and attack scenarios. We have included examples showing the use of error events, escalation events and text annotations for process, collaboration, choreography and conversation diagrams.

Sign in / Sign up

Export Citation Format

Share Document