The Race for Consciousness by John Taylor

Author:John Taylor [Taylor, John]
Language: eng
Format: epub
Published: 2011-02-17T05:00:00+00:00

10

Active Consciousness

I have striven not to laugh at human actions.

—Baruch Spinoza

We are acting all the time, not necessarily in the theatrical sense but with purpose and intent to achieve desirable goals. People and other animals without goals are involved in neither the goings on around them nor, even more crucial, those inside them. Normally, then, we obey the pragmatic transformation of Descartes’ famous dictum ‘‘I think, therefore I am’’

into ‘‘I act, therefore I survive.’’

The actions we make are often laughable, as Spinoza observed, but we make them nevertheless; the ones least likely to cause laughter are those that are carefully planned. Through planning, possibly many steps ahead, we can foresee the consequences of our actions and, if good, make them, if not, do something else. Planning and reasoning are abilities we possess in abundance, together with creativity, far above other animals.

The complexity of the structure of passive consciousness leads us to expect similar or even greater complexity for the active part, since it must incorporate the additional features of attention, drive, control of action, planning, reasoning, and creativity. These processes go beyond the sole involvement of the preprocessing, semantic, emotional, and episodic memory systems discussed thus far in the relational consciousness model.

Some functions of active consciousness that we also consider involve the construction of action-perception sequences, which are used at an automatic level in so many of our goal-seeking endeavors after initial 194

The Global Gate to Consciousness

conscious learning. We also have the unresolved question of where episodic memory is involved—is it only in posterior consciousness, or does it also, or even mainly, contribute to its anterior companion?

Action and thought occur mainly in the frontal lobe of the cortex: motor actions are controlled by the motor cortex, which is just in front of the posterior half of the brain at the beginning of the frontal lobes. Thinking, reasoning, and planning are all crucially tied up with the most forward part of the frontal regions, the prefrontal cortex. I analyze here some of the action-based functions that can be supported by frontal cortex.

Subcortical structures, which are closely coupled with the frontal lobes, especially the basal ganglia and thalamus, must also be considered as part of the brain structures supporting frontal functions.

What do the frontal lobes do? In general, they act as an intermediary between output from posterior cortices (for content) and from the limbic regions (for emotional value of the input) to activate the muscles. As we can see from figure 10.1, the frontal cortex is involved in controlling response to inputs from posterior cortex. Yet the right-hand side of the figure shows that the frontal lobes have a hierarchy of their own, from the motor and premotor cortices directly involved in modulating and initiating motor acts up to the most anterior regions of the dorsolateral prefrontal cortex (figure 10.2).

We can learn about the frontal lobes from a variety of sources: wiring diagrams, measurements made by noninvasive instruments, and other more direct neurophysiological approaches. Thus we can uncover the general nature of motor control by the lower levels of the frontal lobes and their accessory subcortical modules.

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.