Executive brain function

A prevailing pathophysiologic explanation for ADHD symptoms involves dehcits in prefrontal cortex-mediated executive brain function also known as response inhibition. Children with ADHD are unable to control their behavior, resist distractions, and develop an awareness of space and time. In addition, a dysregulation of arousal in frontosubcortical pathways has been proposed. Children with ADHD display insufhcient alertness dming dull and repetitive tasks, alternating with overarousal. ... 

In REM sleep we see this reciprocity at the brain function level. The emotional brain (amygdala) is hyperactive. The executive brain (frontal cortex) is hypoactive. Result emotion is in the saddle. Rational thought is struggling—and failing—to get control of the runaway horse that is the dream. "Don t lose your temper, you say to yourself. This mantra says it all. If you can t maintain top-down control, your emotional brain will get the better of you. 

Executive functions can be sub-classified into volition, planning, purposive action and effective performance. Volition, this most subtle and central realm of human activity (Deutsch Lezak, 1995, p.651), is not usually assessed in drug experiments. Typical tests to assess planning are mazes of different complexity and brain teasers such as the Tower of London or Hanoi In drug experiments with healthy volunteers, purposive action and effective performance are usually measured by means of the methods listed in Tables 3.1 and 3.3. 

What can sleep neurophysiology and the new neuropsychology tell us about lucid dreaming, and how can we use that information to increase our access to that state And what, beyond entertainment, can we learn about the brain-mind from a scientific exploration of lucid dreaming The last question has one ready answer by placing experienced lucid dreamers in a PET scanner (or preferably an fMRI), we could test the hypothesis that, when lucid, dreamers increase the blood flow to their dorsolateral prefrontal cortices as that cortex reactivates to a level consistent with wake state executive function. 

All of this is, of course, standard practice in cognitive behavioral therapy, and I do not pretend that it is in itself innovative. My only contribution is to show how comfortably it sits on the solid foundation of the mind-brain paradigm. At the same time, it calls forth from that paradigm a mechanistic model of change at the level of the brain, namely a shift in balance and in specific connections between the executive functions of the dorsolateral prefrontal cortex and the limbic system. 

When tense, the muscles receive strong excitatory activation from the brain and, in turn, project excitatory activation back to it. When the tension is performance anxiety—as it so often is—the positive feedback loop that perpetuates the excitatory activation of the brain and muscles include the amygdala at the expense of the dorsolateral prefrontal cortex, which is not free to work its executive functions in an adaptive way. Hence memory may be blocked, decisiveness deferred, and creativity crippled. 

The prefrontal cortex (PFC) is the anterior part of the frontal lobes of the brain. It lies in front of the motor and premotor areas. The PFC is divided into the lateral, orbitofrontal, and medial prefrontal areas (Barbas and Pandya, 1987, 1989). Comprehensive reviews of this structure and functions of the PFC have been published in various forms (Fuster, 1997 Goldman-Rakic, 1987 Miller and Cohen, 2001 Passingham, 1993 Tanji and Hoshi, 2008). The PFC possesses a wealth of anatomical connectivity with multiple cortical and subcortical areas, and is involved in broad aspects of behavioral control. The PFC has been implicated in complex cognitive behaviors, social behaviors, and personality expression. Recent studies of this area have revealed its role in the control of a much broader spectrum of functions, such as cross-modal and cross-temporal association of information, in the executive control of behavior, and in the top-down control of neural networks involving the cortical and subcortical areas. Among them, the executive control of action was a term coined to capture various aspects of PFC function. 

Some degree of spellbinding is characteristic of any compromise of frontal lobe function. Beer et al. (2006) noted that orbitofrontal damage is associated with objective inappropriate social behavior. The patients were aware of social norms of intimacy but they were unaware that their task performances violated these norms. The authors call this an impairment of self-monitoring and self-insight. Bach and David (2006) pointed out that self-awareness deficits are very common in patients with traumatic brain injury and key to the development of behavior disturbances Our research found that lack of social self-awareness predicts behavioural disturbance in acquired and traumatic brain injury independent of cognitive and executive function. ... 

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