다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

The unity and diversity of executive functions and their contributions to complex "Frontal Lobe" tasks: a latent variable analysis.

We review evidence for partially segregated networks of brain areas that carry out different attentional functions. One system, which includes parts of the intraparietal cortex and superior frontal cortex, is involved in preparing and applying goal-directed (top-down) selection for stimuli and responses. This system is also modulated by the detection of stimuli. The other system, which includes the temporoparietal cortex and inferior frontal cortex, and is largely lateralized to the right hemisphere, is not involved in top-down selection. Instead, this system is specialized for the detection of behaviourally relevant stimuli, particularly when they are salient or unexpected. This ventral frontoparietal network works as a 'circuit breaker' for the dorsal system, directing attention to salient events. Both attentional systems interact during normal vision, and both are disrupted in unilateral spatial neglect.

Control of goal-directed and stimulus-driven attention in the brain

▪ Abstract The prefrontal cortex has long been suspected to play an important role in cognitive control, in the ability to orchestrate thought and action in accordance with internal goals. Its neural basis, however, has remained a mystery. Here, we propose that cognitive control stems from the active maintenance of patterns of activity in the prefrontal cortex that represent goals and the means to achieve them. They provide bias signals to other brain structures whose net effect is to guide the flow of activity along neural pathways that establish the proper mappings between inputs, internal states, and outputs needed to perform a given task. We review neurophysiological, neurobiological, neuroimaging, and computational studies that support this theory and discuss its implications as well as further issues to be addressed

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An integrative theory of prefrontal cortex function

Publisher Summary This chapter focuses on the modern notion of short-term memory, called working memory. Working memory refers to the temporary maintenance of information that was just experienced or just retrieved from long-term memory but no longer exists in the external environment. These internal representations are short-lived, but can be maintained for longer periods of time through active rehearsal strategies, and can be subjected to various operations that manipulate the information in such a way that makes it useful for goal-directed behavior. Working memory is a system that is critically important in cognition and seems necessary in the course of performing many other cognitive functions, such as reasoning, language comprehension, planning, and spatial processing. This chapter demonstrates the functional importance of dopamine to working memory function in several ways. Elucidation of the cognitive and neural mechanisms underlying human working memory is an important focus of cognitive neuroscience and neurology for much of the past decade. One conclusion that arises from research is that working memory, a faculty that enables temporary storage and manipulation of information in the service of behavioral goals, can be viewed as neither a unitary, nor a dedicated system. Data from numerous neuropsychological and neurophysiological studies in animals and humans demonstrates that a network of brain regions, including the prefrontal cortex, is critical for the active maintenance of internal representations.

Chapter 11 Working memory

The present experiment tested three hypotheses regarding the function and organization of lateral prefrontal cortex (PFC). The first account (the information cascade hypothesis) suggests that the anterior-posterior organization of lateral PFC is based on the timing with which cue stimuli reduce uncertainty in the action selection process. The second account (the levels-of-abstraction hypothesis) suggests that the anterior-posterior organization of lateral PFC is based on the degree of abstraction of the task goals. The current study began by investigating these two hypotheses, and identified several areas of lateral PFC that were predicted to be active by both the information cascade and levels-of-abstraction accounts. However, the pattern of activation across experimental conditions was inconsistent with both theoretical accounts. Specifically, an anterior area of mid-dorsolateral PFC exhibited sensitivity to experimental conditions that, according to both accounts, should have selectively engaged only posterior areas of PFC. We therefore investigated a third possible account (the adaptive context maintenance hypothesis) that postulates that both posterior and anterior regions of PFC are reliably engaged in task conditions requiring active maintenance of contextual information, with the temporal dynamics of activity in these regions flexibly tracking the duration of maintenance demands. Activity patterns in lateral PFC were consistent with this third hypothesis: regions across lateral PFC exhibited transient activation when contextual information had to be updated and maintained in a trial-by-trial manner, but sustained activation when contextual information had to be maintained over a series of trials. These findings prompt a reconceptualization of current views regarding the anterior-posterior organization of lateral PFC, but do support other findings regarding the active maintenance role of lateral PFC in sequential working memory paradigms.

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The Function and Organization of Lateral Prefrontal Cortex: A Test of Competing Hypotheses

The dual mechanisms of control framework postulates that cognitive control can operate in 2 distinct modes: a “proactive” preparatory mode and a “reactive” wait-and-see mode. Importantly, the 2 modes are associated with both costs and benefits in cognitive performance. Here we explore this framework, in terms of its relationship with working memory capacity (WMC). We hypothesize that high-WMC individuals are more likely to utilize proactive control yielding not only benefits, but also specific costs to performance. Across 2 separate, large-sample experiments, healthy young adults performed different variants of the AX-Continuous Performance Test context processing task, a well-established probe of proactive and reactive cognitive control. In 2 experiments, WMC predicted both improvements and relative impairments in task performance in a manner that was consistent with usage of proactive control. These findings suggest that individuals differ in the degree to which they utilize proactive control based on WMC.

/pdf/remembering-to-prepare-the-benefits-and-costs-of-high-4i3t7wq7ro.pdf

Remembering to prepare: The benefits (and costs) of high working memory capacity.

Dissociating proactive and reactive control in the Stroop task (Gonthier et al., M&C, 2016)

Introduction Chapter 1. Todd Braver Motivation and cognitive control Rewards, Cognitive Processing and Goal-Directed Control Chapter 2. Marcus Rothkirch and Philippe Sterzer The role of motivation in visual information processing Chapter 3. Brian Anderson and Anthony Sali The impact of reward on attention: Beyond Motivation Chapter 4. Ruth Krebs, Jens-Max Hopf and Carsten Boehler Within-trial effects of stimulus-reward associations Chapter 5. Mauricio Delgado, Susan Ravizza and Anthony Porcelli Motivational influences on cognitive control: The role of reward processing Chapter 6. Wim Notebaert and Senne Braem Parsing the effects of reward on cognitive control Chapter 7. Sanne de Wit and Anthony Dickinson Ideomotor mechanisms of goal-directed behavior Affect, Conflict and Self-Regulation Chapter 8. Hans Marien, Henk Aarts and Ruud Custers How goals control behavior: The role of action-outcome and reward information Chapter 9. Philip Gable, Lauren Browning and Eddie Harmon-Jones Affect, motivation, and cognitive scope Chapter 10. Gesine Dreisbach and Rico Fischer Conflicts as aversive signals: Motivation for control adaptation in the service of affect regulation Chapter 11. Blair Saunders and Michael Inzlicht Vigor and fatigue: How variation in affect underlies effective self-control Chapter 12. Clay Holroyd The waste disposal problem of effortful control Age-related changes in cognitive motivation Chapter 13. BJ Casey and Adriana Galvan The teen brain: "Arrested development" in resisting temptation Chapter 14. Shu-Chen Li and Ben Eppinger Lifespan development of adaptive neurocognitive representations: Reciprocal interactions between cognition and motivation Chapter 15. Todd Maddox, Marissa Gorlick and Darrell Worthy Towards a three-factor motivation-learning framework in normal aging Chapter 16. Thomas Hess and Brian Smith Linkages between age-related changes in the costs of cognitive engagement, motivation, and behavior Chapter 17. Ishabel Vicaria and Derek Isaacowitz Age-related changes in motivation: Do they influence emotional experience across adulthood and old age?

Motivation and Cognitive Control

The Dual Mechanisms of Control framework posits the existence of two distinct control mechanisms, proactive and reactive, which may operate independently. However, this independence has been difficult to study with most experimental paradigms. The Stroop task may provide a useful way of assessing the independence of control mechanisms because the task elicits two types of proportion congruency effects, list-wide and item-specific, thought to reflect proactive and reactive control respectively. The present research tested whether these two proportion congruency effects can be used to dissociate proactive and reactive control. In 2 separate participant samples, we demonstrate that list-wide and item-specific proportion congruency effects are stable, exist in the same participants, and appear in different task conditions. Moreover, we identify two distinct behavioral signatures, the congruency cost and the transfer cost, which doubly dissociate the two effects. Together, the results are consistent with the view that proactive and reactive control reflect independent mechanisms.

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Todd S. Braver

Papers

The Function and Organization of Lateral Prefrontal Cortex: A Test of Competing Hypotheses

Remembering to prepare: The benefits (and costs) of high working memory capacity.

Dissociating proactive and reactive control in the Stroop task (Gonthier et al., M&C, 2016)

Motivation and Cognitive Control

Dissociating proactive and reactive control in the Stroop task