Nucleus accumbens is involved in human action monitoring: evidence from invasive electrophysiological recordings

The Nucleus accumbens (Nacc) has been proposed to act as a limbic-motor interface. Here, using invasive intraoperative recordings in an awake patient suffering from obsessive-compulsive disease (OCD), we demonstrate that its activity is modulated by the quality of performance of the subject in a choice reaction time task designed to tap action monitoring processes. Action monitoring, that is, error detection and correction, is thought to be supported by a system involving the dopaminergic midbrain, the basal ganglia, and the medial prefrontal cortex. In surface electrophysiological recordings, action monitoring is indexed by an error-related negativity (ERN) appearing time-locked to the erroneous responses and emanating from the medial frontal cortex. In preoperative scalp recordings the patient's ERN was found to be signifi cantly increased compared to a large (n = 83) normal sample, suggesting enhanced action monitoring processes. Intraoperatively, error-related modulations were obtained from the Nacc but not from a site 5 mm above. Importantly, crosscorrelation analysis showed that error-related activity in the Nacc preceded surface activity by 40 ms. We propose that the Nacc is involved in action monitoring, possibly by using error signals from the dopaminergic midbrain to adjust the relative impact of limbic and prefrontal inputs on frontal control systems in order to optimize goal-directed behavior.

Formal Power Analysis of Systems-on-Chip

The design methods and languages targeted to modern System-on-Chip designs are facing tremendous pressure of the ever-increasing complexity, power, and speed requirements. To estimate any of these three metrics, there is a trade-off between accuracy and abstraction level of detail in which a system under design is analyzed. The more detailed the description, the more accurate the simulation will be, but, on the other hand, the more time consuming it will be. Moreover, a designer wants to make decisions as early as possible in the design flow to avoid costly design backtracking. To answer the challenges posed upon System-on-chip designs, this thesis introduces a formal, power aware framework, its development methods, and methods to constraint and analyze power consumption of the system under design. This thesis discusses on power analysis of synchronous and asynchronous systems not forgetting the communication aspects of these systems. The presented framework is built upon the Timed Action System formalism, which offer an environment to analyze and constraint the functional and temporal behavior of the system at high abstraction level. Furthermore, due to the complexity of System-on-Chip designs, the possibility to abstract unnecessary implementation details at higher abstraction levels is an essential part of the introduced design framework. With the encapsulation and abstraction techniques incorporated with the procedure based communication allows a designer to use the presented power aware framework in modeling these large scale systems. The introduced techniques also enable one to subdivide the development of communication and computation into own tasks. This property is taken into account in the power analysis part as well. Furthermore, the presented framework is developed in a way that it can be used throughout the design project. In other words, a designer is able to model and analyze systems from an abstract specification down to an implementable specification.

Le Droit des peuples : organe d'action socialiste nationale et internationale et de défense des réfugiés alsaciens, lorrains, belges, français

1918/08/23 (A1,N32)-1918/08/29.

Le Droit des peuples : organe d'action socialiste nationale et internationale et de défense des réfugiés alsaciens, lorrains, belges, français

1918/01/18 (A1,N1)-1918/01/24.

Le Droit des peuples : organe d'action socialiste nationale et internationale et de défense des réfugiés alsaciens, lorrains, belges, français

1918/07/19 (A1,N26)-1918/07/25.

Le Droit des peuples : organe d'action socialiste nationale et internationale et de défense des réfugiés alsaciens, lorrains, belges, français

1918/09/06 (A1,N34)-1918/09/12.

Le Droit des peuples : organe d'action socialiste nationale et internationale et de défense des réfugiés alsaciens, lorrains, belges, français

1918/08/30 (A1,N33)-1918/09/05.

Le Droit des peuples : organe d'action socialiste nationale et internationale et de défense des réfugiés alsaciens, lorrains, belges, français

1918/04/12 (A1,N13)-1918/04/18.

Le Droit des peuples : organe d'action socialiste nationale et internationale et de défense des réfugiés alsaciens, lorrains, belges, français

1918/08/02 (A1,N29)-1918/08/08.

Le Droit des peuples : organe d'action socialiste nationale et internationale et de défense des réfugiés alsaciens, lorrains, belges, français

1918/03/22 (A1,N10)-1918/03/28.

Le Droit des peuples : organe d'action socialiste nationale et internationale et de défense des réfugiés alsaciens, lorrains, belges, français

1918/02/15 (A1,N5)-1918/02/22.

Le Droit des peuples : organe d'action socialiste nationale et internationale et de défense des réfugiés alsaciens, lorrains, belges, français

1918/10/25 (A1,N41)-1918/10/31.

Le Droit des peuples : organe d'action socialiste nationale et internationale et de défense des réfugiés alsaciens, lorrains, belges, français

1918/03/15 (A1,N9)-1918/03/21.

Le Droit des peuples : organe d'action socialiste nationale et internationale et de défense des réfugiés alsaciens, lorrains, belges, français

1918/02/08 (A1,N4)-1918/02/14.

Le Droit des peuples : organe d'action socialiste nationale et internationale et de défense des réfugiés alsaciens, lorrains, belges, français

1918/02/22 (A1,N6)-1918/02/28.