Investigating Modality-Specific Control Mechanisms With a Temporal Flanker Task

2008 ◽  
Author(s):  
Hillary Schwarb ◽  
Eliot Hazeltine ◽  
Eric H. Schumacher ◽  
Travis L. Seymour
2001 ◽  
Vol 120 (5) ◽  
pp. A502-A502
Author(s):  
R GAUTHIER ◽  
J DROLET ◽  
J REED ◽  
A VEZINA ◽  
P VACHON

1996 ◽  
Vol 76 (1) ◽  
pp. 193-244 ◽  
Author(s):  
P. B. Persson

It is generally held that the role of a specific control element can only be understood within its physiological environment. The reviewed studies make it clear that there is a potent interplay between locally produced substances such as adenosine, nitric oxide, prostaglandins, and various others all interacting with the central level of control. This can occur at central sites (e.g., nitric oxide in the brain) or in the periphery (e.g., neural influence on autoregulation). The interactions are more or less pronounced during specific physiological challenges. Furthermore, several of these interactions are altered under pathological circumstances, and in some cases, the interactions seem to maintain or even augment the severity of disease. When more than three parameters participate in an interaction, the resulting regulation may become extremely complex. If these parameters are nonlinearly coupled with each other, the only way to shed light onto the nature of control network is by treating it as a black box. With the use of spectral analysis or nonlinear methods, it is possible to disentangle the fundamental nature of the system in terms of the complexity and stability. Therefore, modern developments in cardiovascular physiology utilizing these techniques, some of which are derived from the "chaos theory," are reviewed.


2013 ◽  
Vol 42 (4) ◽  
pp. 2282-2294 ◽  
Author(s):  
Zhenfang Wu ◽  
Jingfang Liu ◽  
Haibo Yang ◽  
Hailong Liu ◽  
Hua Xiang

Abstract The use of multiple replication origins in archaea is not well understood. In particular, little is known about their specific control mechanisms. Here, we investigated the active replication origins in the three replicons of a halophilic archaeon, Haloarcula hispanica, by extensive gene deletion, DNA mutation and genome-wide marker frequency analyses. We revealed that individual origins are specifically dependent on their co-located cdc6 genes, and a single active origin/cdc6 pairing is essential and sufficient for each replicon. Notably, we demonstrated that the activities of oriC1 and oriC2, the two origins on the main chromosome, are differently controlled. A G-rich inverted repeat located in the internal region between the two inverted origin recognition boxes (ORBs) plays as an enhancer for oriC1, whereas the replication initiation at oriC2 is negatively regulated by an ORB-rich region located downstream of oriC2-cdc6E, likely via Cdc6E-titrating. The oriC2 placed on a plasmid is incompatible with the wild-type (but not the ΔoriC2) host strain, further indicating that strict control of the oriC2 activity is important for the cell. This is the first report revealing diverse control mechanisms of origins in haloarchaea, which has provided novel insights into the use and coordination of multiple replication origins in the domain of Archaea.


2001 ◽  
Vol 280 (6) ◽  
pp. C1540-C1554 ◽  
Author(s):  
Rémy Gauthier ◽  
Charlène Harnois ◽  
Jean-François Drolet ◽  
John C. Reed ◽  
Anne Vézina ◽  
...  

To investigate whether human intestinal epithelial cell survival involves distinct control mechanisms depending on the state of differentiation, we analyzed the in vitro effects of insulin, pharmacological inhibitors of Fak, MEK/Erk, and PI3-K/Akt, and integrin (β1, β4)-blocking antibodies on the survival of the well-established human Caco-2 enterocyte-like and HIEC-6 cryptlike cell models. In addition, relative expression levels of six Bcl-2 homologs (Bcl-2, Bcl-XL, Mcl-1, Bax, Bak, and Bad) and activation levels of Fak, Erk-2, and Akt were analyzed. Herein, we report that 1) the enterocytic differentiation process results in the establishment of distinct profiles of Bcl-2 homolog expression levels, as well as p125Fak, p42Erk-2, and p57Aktactivated levels; 2) the inhibition of Fak, of the MEK/Erk pathway, or of PI3-K, have distinct impacts on enterocytic cell survival in undifferentiated (subconfluent Caco-2, confluent HIEC-6) and differentiated (30 days postconfluent Caco-2) cells; 3) exposure to insulin and the inhibition of Fak, MEK, and PI3-K resulted in differentiation state-distinct modulations in the expression of each Bcl-2 homolog analyzed; and 4) Fak, β1 and β4 integrins, as well as the MEK/Erk and PI3-K/Akt pathways, are distinctively involved in cell survival depending on the state of cell differentiation. Taken together, these data indicate that human intestinal epithelial cell survival is regulated according to differentiation state-specific control mechanisms.


Author(s):  
David Dignath ◽  
Andrea Kiesel

Abstract. In response-interference tasks, congruency effects are reduced in trials that follow an incongruent trial. This congruence sequence effect (CSE) has been taken to reflect top-down cognitive control processes that monitor for and intervene in case of conflict. In contrast, episodic-memory accounts explain CSEs with bottom-up retrieval of stimulus-response links. Reconciling these opposing views, an emerging perspective holds that memory stores instances of control – abstract control-states – creating a shortcut for effortful control processes. Support comes from a study that assessed CSEs in a prime-target task. Here, repeating an irrelevant context feature boosted CSEs, possibly by retrieving previously stored control-states. We present a conceptual replication using the Eriksen flanker task because previous research found that CSEs in the flanker task reflect different control mechanisms than CSEs in the prime-target task. We measured CSEs while controlling for stimulus–response memory effects and manipulated contextual information (vertical spatial location) independently from the stimulus information, which introduced the conflict (horizontal spatial location). Results replicate previous findings – CSEs increased for context-repetition compared to context-changes. This study shows that retrieval of control-states is not limited to a specific task or context feature and therefore generalizes the notion that abstract control parameters are stored into trial-specific event files.


2012 ◽  
Vol 24 (5) ◽  
pp. 1264-1274 ◽  
Author(s):  
Roland Nigbur ◽  
Michael X Cohen ◽  
K. Richard Ridderinkhof ◽  
Birgit Stürmer

Cognitive control allows us to adjust to environmental changes. The medial frontal cortex (MFC) is thought to detect conflicts and recruit additional resources from other brain areas including the lateral prefrontal cortices. Here we investigated how the MFC acts in concert with visual, motor, and lateral prefrontal cortices to support adaptations of goal-directed behavior. Physiologically, these interactions may occur through local and long-range synchronized oscillation dynamics, particularly in the theta range (4–8 Hz). A speeded flanker task allowed us to investigate conflict-type-specific control networks for perceptual and response conflicts. Theta power over MFC was sensitive to both perceptual and response conflict. Interareal theta phase synchrony, however, indicated a selective enhancement specific for response conflicts between MFC and left frontal cortex as well as between MFC and the presumed motor cortex contralateral to the response hand. These findings suggest that MFC theta-band activity is both generally involved in conflict processing and specifically involved in linking a neural network controlling response conflict.


2019 ◽  
Vol 72 (8) ◽  
pp. 1984-1997 ◽  
Author(s):  
Lu Jiao ◽  
Cong Liu ◽  
Lijuan Liang ◽  
Patrick Plummer ◽  
Charles A Perfetti ◽  
...  

Previous studies have suggested that bilingual production experience has beneficial effects on executive functions. In the current study, four experiments were conducted to investigate whether bilingual comprehension experience influences executive functions. In Experiments 1 and 2, Chinese–English bilinguals completed a flanker task interleaved with a language comprehension task (reading comprehension in Experiment 1 and listening comprehension in Experiment 2). There were three blocks distinguished by language context, with a Chinese (L1) block, an English (L2) block, and a mixed (L1 and L2) block. Results showed that performance in the mixed block was better on both congruent and incongruent flanker trials when compared with the L1 and L2 blocks, indicating better monitoring functions overall. In Experiments 3 and 4 (reading comprehension and listening comprehension, respectively), participants were also exposed to three language contexts (i.e., L1, L2, and mixed block) but performed a non-conflict control task that did not require any conflict resolution. The results of Experiments 3 and 4 showed similar performance under the three different language contexts. Taken together, these results indicate that language control mechanisms involved in bilingual comprehension contribute to domain-general executive control performance. The results suggest a monitoring mechanism establishes a bridge connecting executive functions and bilingual language control during comprehension.


2014 ◽  
Vol 2014 ◽  
pp. 1-20 ◽  
Author(s):  
Tanya Dash ◽  
Bhoomika R. Kar

Background. Bilingualism results in an added advantage with respect to cognitive control. The interaction between bilingual language control and general purpose cognitive control systems can also be understood by studying executive control among individuals with bilingual aphasia.Objectives. The current study examined the subcomponents of cognitive control in bilingual aphasia. A case study approach was used to investigate whether cognitive control and language control are two separate systems and how factors related to bilingualism interact with control processes.Methods. Four individuals with bilingual aphasia performed a language background questionnaire, picture description task, and two experimental tasks (nonlinguistic negative priming task and linguistic and nonlinguistic versions of flanker task).Results. A descriptive approach was used to analyse the data using reaction time and accuracy measures. The cumulative distribution function plots were used to visualize the variations in performance across conditions. The results highlight the distinction between general purpose cognitive control and bilingual language control mechanisms.Conclusion. All participants showed predominant use of the reactive control mechanism to compensate for the limited resources system. Independent yet interactive systems for bilingual language control and general purpose cognitive control were postulated based on the experimental data derived from individuals with bilingual aphasia.


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