scholarly journals The dual nature of the BOLD signal: Responses in visual area hMT + reflect both input properties and perceptual decision

2021 ◽  
Vol 42 (6) ◽  
pp. 1920-1929
Author(s):  
Teresa Sousa ◽  
João V. Duarte ◽  
Gabriel N. Costa ◽  
Valentin G. Kemper ◽  
Ricardo Martins ◽  
...  
2017 ◽  
Vol 281 ◽  
pp. 21-32 ◽  
Author(s):  
Paul M. Krueger ◽  
Marieke K. van Vugt ◽  
Patrick Simen ◽  
Leigh Nystrom ◽  
Philip Holmes ◽  
...  

2018 ◽  
Vol 41 ◽  
Author(s):  
Patrick Simen ◽  
Fuat Balcı

AbstractRahnev & Denison (R&D) argue against normative theories and in favor of a more descriptive “standard observer model” of perceptual decision making. We agree with the authors in many respects, but we argue that optimality (specifically, reward-rate maximization) has proved demonstrably useful as a hypothesis, contrary to the authors’ claims.


2020 ◽  
Vol 134 (18) ◽  
pp. 2447-2451
Author(s):  
Anissa Viveiros ◽  
Gavin Y. Oudit

Abstract The global prevalence of obesity has been rising at an alarming rate, accompanied by an increase in both childhood and maternal obesity. The concept of metabolic programming is highly topical, and in this context, describes a predisposition of offspring of obese mothers to the development of obesity independent of environmental factors. Research published in this issue of Clinical Science conducted by Litzenburger and colleagues (Clin. Sci. (Lond.) (2020) 134, 921–939) have identified sex-dependent differences in metabolic programming and identify putative signaling pathways involved in the differential phenotype of adipose tissue between males and females. Delineating the distinction between metabolically healthy and unhealthy obesity is a topic of emerging interest, and the precise nature of adipocytes are key to pathogenesis, independent of adipose tissue volume.


2016 ◽  
Vol 30 (4) ◽  
pp. 165-174 ◽  
Author(s):  
Ryan Smith ◽  
John J.B. Allen ◽  
Julian F. Thayer ◽  
Richard D. Lane

Abstract. We hypothesized that in healthy subjects differences in resting heart rate variability (rHRV) would be associated with differences in emotional reactivity within the medial visceromotor network (MVN). We also probed whether this MVN-rHRV relationship was diminished in depression. Eleven healthy adults and nine depressed subjects performed the emotional counting stroop task in alternating blocks of emotion and neutral words during functional magnetic resonance imaging (fMRI). The correlation between rHRV outside the scanner and BOLD signal reactivity (absolute value of change between adjacent blocks in the BOLD signal) was examined in specific MVN regions. Significant negative correlations were observed between rHRV and average BOLD shift magnitude (BSM) in several MVN regions in healthy subjects but not depressed subjects. This preliminary report provides novel evidence relating emotional reactivity in MVN regions to rHRV. It also provides preliminary suggestive evidence that depression may involve reduced interaction between the MVN and cardiac vagal control.


1968 ◽  
Vol 57 (3_Suppl) ◽  
pp. S19-S35 ◽  
Author(s):  
Å. Hjalmarson

ABSTRACT In vitro addition of bovine growth hormone (GH) to intact hemidiaphragms from hypophysectomized rats has previously been found to produce both an early stimulatory effect lasting for 2—3 hours and a subsequent late inhibitory effect during which the muscle is insensitive to further addition of GH (Hjalmarson 1968). These effects on the accumulation rate of α-aminoisobutyric acid (AIB) and D-xylose have been further studied. In presence of actinomycin D (20 μg/ml) or puromycin (100 μg/ml) the duration of the stimulatory effect of GH (25 μg/ml) was prolonged to last for at least 4—5 hours and the late inhibitory effect was prevented. Similar results were obtained when glucose-free incubation medium was used. Preincubation of the diaphragm at different glucose concentrations (0—5 mg/ml) for 3 hours did not change the GH sensitivity. Addition of insulin at start of incubation could not prevent GH from inducing its late inhibitory effect, while dexamethasone seemed to potentiate this effect of GH. Furthermore, adrenaline was found to decrease the uptake of AIB-14C and D-xylose-14C in the diaphragm, but not to change the sensitivity of the muscle to GH. Preincubation of the diaphragm for 3 hours with puromycin in a concentration of 200 μg/ml markedly decreased the subsequent basal uptake of both AIB-14C and D-xylose-14C, in the presence of puromycin, and abolished the stimulatory effect of GH on the accumulation of AIB-14C. However, the effect of GH on the accumulation of D-xylose-14C was unchanged. The present observations are discussed and evaluated in relation to various mechanisms of GH action proposed to explain the dual nature of the hormone.


Author(s):  
Tara A Shrout

Cardiac hypertrophy is a growth process that occurs in response to stress stimuli or injury, and leads to the induction of several pathways to alter gene expression. Under hypertrophic stimuli, sarcomeric structure is disrupted, both as a consequence of gene expression and local changes in sarcomeric proteins. Cardiac-restricted ankyrin repeat protein (CARP) is one such protein that function both in cardiac sarcomeres and at the transcriptional level. We postulate that due to this dual nature, CARP plays a key role in maintaining the cardiac sarcomere. GATA4 is another protein detected in cardiomyocytes as important in hypertrophy, as it is activated by hypertrophic stimuli, and directly binds to DNA to alter gene expression. Results of GATA4 activation over time were inconclusive; however, the role of CARP in mediating hypertrophic growth in cardiomyocytes was clearly demonstrated. In this study, Neonatal Rat Ventricular Myocytes were used as a model to detect changes over time in CARP and GATA4 under hypertrophic stimulation by phenylephrine and high serum media. Results were detected by analysis of immunoblotting. The specific role that CARP plays in mediating cellular growth under hypertrophic stimuli was studied through immunofluorescence, which demonstrated that cardiomyocyte growth with hypertrophic stimulation was significantly blunted when NRVMs were co-treated with CARP siRNA. These data suggest that CARP plays an important role in the hypertrophic response in cardiomyocytes.


2020 ◽  
Vol 63 (2) ◽  
pp. 46-62
Author(s):  
Suren T. Zolyan

We discuss the role of linguistic metaphors as a cognitive frame for the understanding of genetic information processing. The essential similarity between language and genetic information processing has been recognized since the very beginning, and many prominent scholars have noted the possibility of considering genes and genomes as texts or languages. Most of the core terms in molecular biology are based on linguistic metaphors. The processing of genetic information is understood as some operations on text – writing, reading and editing and their specification (encoding/decoding, proofreading, transcription, translation, reading frame). The concept of gene reading can be traced from the archaic idea of the equation of Life and Nature with the Book. Thus, the genetics itself can be metaphorically represented as some operations on text (deciphering, understanding, code-breaking, transcribing, editing, etc.), which are performed by scientists. At the same time linguistic metaphors portrayed gene entities also as having the ability of reading. In the case of such “bio-reading” some essential features similar to the processes of human reading can be revealed: this is an ability to identify the biochemical sequences based on their function in an abstract system and distinguish between type and its contextual tokens of the same type. Metaphors seem to be an effective instrument for representation, as they make possible a two-dimensional description: biochemical by its experimental empirical results and textual based on the cognitive models of comprehension. In addition to their heuristic value, linguistic metaphors are based on the essential characteristics of genetic information derived from its dual nature: biochemical by its substance, textual (or quasi-textual) by its formal organization. It can be concluded that linguistic metaphors denoting biochemical objects and processes seem to be a method of description and explanation of these heterogeneous properties.


Author(s):  
Gaurav Mattey ◽  
Lava Ranganathan

Abstract Critical speed path analysis using Dynamic Laser Stimulation (DLS) technique has been an indispensable technology used in the Semiconductor IC industry for identifying process defects, design and layout issues that limit product speed performance. Primarily by injecting heat or injecting photocurrent in the active diffusion of the transistors, the laser either slows down or speeds up the switching speed of transistors, thereby affecting the overall speed performance of the chip and revealing the speed limiting/enhancing circuits. However, recently on Qualcomm Technologies’ 14nm FinFET technology SOC product, the 1340nm laser’s heating characteristic revealed a Vt (threshold voltage) improvement behavior at low operating voltages which helped identify process issues on multiple memory array blocks across multiple cores failing for MBIST (Memory Built-in Self-test). In this paper, we explore the innovative approach of using the laser to study Vt shifts in transistors due to process issues. We also study the laser silicon interactions through scanning the 1340nm thermal laser on silicon and observing frequency shifts in a high-speed Ring Oscillator (RO) on 16nm FinFET technology. This revealed the normal and reverse Temperature Dependency Gate voltages for 16nm FinFET, thereby illustrating the dual nature of stimulation (reducing mobility and improving Vt) from a thermal laser. Frequency mapping through Laser Voltage Imaging (LVI) was performed on the Ring Oscillator (RO) using the 1340nm thermal laser, while concurrently stimulating the transistors of the RO. Spatial distribution of stimulation was studied by observing the frequency changes on LVI.


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