scholarly journals Top–Down Attentional Modulation in Human Frontal Cortex: Differential Engagement during External and Internal Attention

2020 ◽  
Author(s):  
Julia W Y Kam ◽  
Randolph F Helfrich ◽  
Anne-Kristin Solbakk ◽  
Tor Endestad ◽  
Pål G Larsson ◽  
...  

Abstract Decades of electrophysiological research on top–down control converge on the role of the lateral frontal cortex in facilitating attention to behaviorally relevant external inputs. However, the involvement of frontal cortex in the top–down control of attention directed to the external versus internal environment remains poorly understood. To address this, we recorded intracranial electrocorticography while subjects directed their attention externally to tones and responded to infrequent target tones, or internally to their own thoughts while ignoring the tones. Our analyses focused on frontal and temporal cortices. We first computed the target effect, as indexed by the difference in high frequency activity (70–150 Hz) between target and standard tones. Importantly, we then compared the target effect between external and internal attention, reflecting a top–down attentional effect elicited by task demands, in each region of interest. Both frontal and temporal cortices showed target effects during external and internal attention, suggesting this effect is present irrespective of attention states. However, only the frontal cortex showed an enhanced target effect during external relative to internal attention. These findings provide electrophysiological evidence for top–down attentional modulation in the lateral frontal cortex, revealing preferential engagement with external attention.

2001 ◽  
Vol 11 ◽  
pp. S282-S283
Author(s):  
D. Marazziti ◽  
I. Masala ◽  
G. Giannaccini ◽  
E. Di Nasso ◽  
L. Betti ◽  
...  

Life Sciences ◽  
1999 ◽  
Vol 65 (22) ◽  
pp. 2315-2323 ◽  
Author(s):  
Hiroki Ozawa ◽  
Wataru Ukai ◽  
Johannes Kornhuber ◽  
Takafumi Yamaguchi ◽  
Lutz Froelich ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ellis Patrick ◽  
Marta Olah ◽  
Mariko Taga ◽  
Hans-Ulrich Klein ◽  
Jishu Xu ◽  
...  

AbstractMicroglial dysfunction has been proposed as one of the many cellular mechanisms that can contribute to the development of Alzheimer’s disease (AD). Here, using a transcriptional network map of the human frontal cortex, we identify five modules of co-expressed genes related to microglia and assess their role in the neuropathologic features of AD in 540 subjects from two cohort studies of brain aging. Two of these transcriptional programs—modules 113 and 114—relate to the accumulation of β-amyloid, while module 5 relates to tau pathology. We replicate these associations in brain epigenomic data and in two independent datasets. In terms of tau, we propose that module 5, a marker of activated microglia, may lead to tau accumulation and subsequent cognitive decline. We validate our model further by showing that three representative module 5 genes (ACADVL, TRABD, and VASP) encode proteins that are upregulated in activated microglia in AD.


2021 ◽  
pp. 197140092110497
Author(s):  
Tetsuya Hashimoto ◽  
Takenobu Kunieda ◽  
Tristan Honda ◽  
Fabien Scalzo ◽  
Latisha K Sharma ◽  
...  

Background The potential heterogeneity in occlusive thrombi caused by in situ propagation by secondary thrombosis after embolic occlusion could obscure the characteristics of original thrombi, preventing the clarification of a specific thrombus signature for the etiology of ischemic stroke. We aimed to investigate the heterogeneity of occlusive thrombi by pretreatment imaging. Methods Among consecutive stroke patients with acute embolic anterior circulation large vessel occlusion treated with thrombectomy, we retrospectively reviewed 104 patients with visible occlusive thrombi on pretreatment non-contrast computed tomography admitted from January 2015 to December 2018. A region of interest was set on the whole thrombus on non-contrast computed tomography under the guidance of computed tomography angiography. The region of interest was divided equally into the proximal and distal segments and the difference in Hounsfield unit densities between the two segments was calculated. Results Hounsfield unit density in the proximal segment was higher than that in the distal segment (mean difference 4.45; p < 0.001), regardless of stroke subtypes. On multivariate analysis, thrombus length was positively correlated (β = 0.25; p < 0.001) and time from last-known-well to imaging was inversely correlated (β = −0.0041; p = 0.002) with the difference in Hounsfield unit densities between the proximal and distal segments. Conclusions The difference in density between the proximal and distal segments increased as thrombi became longer and decreased as thrombi became older after embolic occlusion. This time/length-dependent thrombus heterogeneity between the two segments is suggestive of secondary thrombosis initially occurring on the proximal side of the occlusion.


2021 ◽  
Vol 5 (2) ◽  
pp. 405
Author(s):  
Lussi Agustin ◽  
Moh. Yusron Solikin ◽  
Zunairoh .

Penelitian ini bertujuan untuk menganalisis seberapa maksimal proses kebijakan retrukturisasi Kredit UMKM dalam Pemulihan Ekonomi di Masa Pandemi Covid-19. Kondisi perekonomian global sedang mengalami goncangan hebat akibat mewabahnya Covid-19. Dampak dari pandemic ini sangat mempengaruhi segala aspek terutama pada kondisi Kesehatan dan perekonomian suatu negara, tidak terkecuali Indonesia. Secara keseluruhan, hampir semua sektor industry mengalami goncangan dan tidak terkecuali sektor UMKM. Maka dari itu dikeluarkanlah kebijakan retrukturisasi Kredit UMKM guna mendorong optimalisasi fungsi intermediasi pada perbankan dan menjaga stabilitas sistem keuangan serta mendukung pertumbuhan perekonomian. Program restrukturisasi kredit menjadi program dari OJK yang dapat diterapkan oleh perbankan kepada UMKM. Metode yang digunakan dalam penelitian ini adalah metode kualitatif dengan menggunakan studi empiris dari penelitian terdahulu serta peraturan-peraturan terkait dengan restrukturisasi kredit yang dikeluarkan oleh Otoritas Jasa Keuangan. Hasil penelitian ini menunjukkan bahwa implementasi kebijakan restrukturisai kredit bagi UMKM sudah berjalan dan digunakan oleh para pelaku UMKM. Kemudian berdasarkan implementasinya kebijakan ini merupakan kebijakan top-down dimana memerlukan banyak Lembaga untuk bekerja sama dan keputusan berasal dari Peraturan pemerintah baru di teruskan ke Lembaga-lembaga lain di bawahnya hingga informasinya sampai dan bisa dirasakan oleh para UMKM.  This research aims to analyze the policy of restructuring SMEs Credit in Economic Recovery during the Covid-19 Pandemic. The global economy is experiencing severe shocks due to the outbreak of Covid-19. The impact of this pandemic greatly affects all aspects, especially on the health and economic condition of a country, not least Indonesia. Overall, almost all industry sectors are experiencing shocks and are no exception to the SMEs sector. Therefore, the policy of restructuring SMEs Credit was issued to encourage optimization of intermediation function in banking and maintain the financial system stability and support economic growth. Credit restructuring program becomes a program from OJK that can be applied by banks to SMEs. The method used in this research is a qualitative method using empirical studies from previous research as well as regulations related to credit restructuring issued by the Financial Services Authority. The results of this research show that the implementation of credit restructuring policy for SMEs is already running and used by SMEs. Then based on the difference in implementation of this policy is a top-down policy that requires many Institutions to cooperate and decisions derived from the new government regulations are forwarded to other institutions under it until the information reaches and can be felt by SMEs.


2012 ◽  
Vol 12 (11) ◽  
pp. 29915-29965 ◽  
Author(s):  
W. Stremme ◽  
M. Grutter ◽  
C. Rivera ◽  
A. Bezanilla ◽  
A. R. Garcia ◽  
...  

Abstract. Continuous carbon monoxide (CO) total column densities above the UNAM campus in Mexico City have been derived from solar absorption infrared spectroscopic measurements since October 2007. Its diurnal evolution is used in the present study in conjunction with other ground-based and satellite data to develop a top-down emission estimate of the annual CO emission of the Mexico City Metropolitan Area (MCMA). The growth-rate of the total column around noon under low ventilation conditions is calculated and allows us to derive the average surface emission-flux at UNAM, while similar measurements taken at the edge of the MCMA in Tecámac provides information on background CO levels in the Mexico basin. Based on 3 yr of measurements, CO column measurements from the IASI satellite instrument are used to reconstruct the spatial distribution of this anthropogenic pollutant over the MCMA. The agreement between the measured columns of the satellite and ground-based measurements is excellent, particularly when a comparison strategy based on time-displaced air masses is used. The annual emission of the Mexico Megacity is estimated to be (2.15 ± 0.5) Tg yr−1 for the year 2008, while the official inventory for that year reported 1.6 Tg yr−1. The difference is slightly higher than the conservative uncertainty estimated in this work suggesting that the emission might be underestimated by the conventional bottom-up method. A larger discrepancy is found in the spatial distribution of the emissions, when comparing the emission flux over UNAM (derived from the ground-based measurement) with that of the inventory integrated over a representative area. The methodology presented here represents a new and useful strategy to evaluate the contribution of megacities to the global anthropogenic gas emissions. Additionally, three different strategies to compare ground and space-based measurements above an inhomogeneous and strongly contaminated area like Mexico City are presented and discussed.


2018 ◽  
Vol 6 (9) ◽  
pp. e180 ◽  
Author(s):  
Giuseppe Piegari ◽  
Valentina Iovane ◽  
Vincenzo Carletti ◽  
Rosario Fico ◽  
Alessandro Costagliola ◽  
...  

Background Google Glass is a head-mounted device designed in the shape of a pair of eyeglasses equipped with a 5.0-megapixel integrated camera and capable of taking pictures with simple voice commands. Objective The objective of our study was to determine whether Google Glass is fit for veterinary forensic pathology purposes. Methods A total of 44 forensic necropsies of 2 different species (22 dogs and 22 cats) were performed by 2 pathologists; each pathologist conducted 11 necropsies of each species and, for each photographic acquisition, the images were taken with a Google Glass device and a Nikon D3200 digital single-lens reflex (DSLR) camera. The pictures were collected, divided into 3 groups (based on the external appearance of the animal, organs, and anatomical details), and evaluated by 5 forensic pathologists using a 5-point score system. The parameters assessed were overall color settings, region of interest, sharpness, and brightness. To evaluate the difference in mean duration between necropsies conduced with Google Glass and DSLR camera and to assess the battery consumption of the devices, an additional number of 16 necropsies were performed by the 2 pathologists. In these cases, Google Glass was used for photographic reports in 8 cases (4 dogs and 4 cats) and a Nikon D3200 reflex camera in the other 8 cases. Statistical evaluations were performed to assess the differences in ratings between the quality of the images taken with both devices. Results The images taken with Google Glass received significantly lower ratings than those acquired with reflex camera for all 4 assessed parameters (P<.001). In particular, for the pictures of Groups A and B taken with Google Glass, the sum of frequency of ratings 5 (very good) and 4 (good) was between 50% and 77% for all 4 assessed parameters. The lowest ratings were observed for the pictures of Group C, with a sum of frequency of ratings 5 and 4 of 21.1% (342/1602) for region of interest, 26% (421/1602) for sharpness, 35.5% (575/1602) for overall color settings, and 61.4% (995/1602) for brightness. Furthermore, we found a significant reduction in the mean execution time for necropsy conduced with the Google Glass with respect to the reflex group (P<.001). However, Google Glass drained the battery very quickly. Conclusions These findings suggest that Google Glass is usable in veterinary forensic pathology. In particular, the image quality of Groups A and B seemed adequate for forensic photographic documentation purposes, although the quality was lower than that with the reflex camera. However, in this step of development, the high frequency of poor ratings observed for the pictures of Group C suggest that the device is not suitable for taking pictures of small anatomical details or close-ups of the injuries.


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