324 BRAINS OF RATS AND MEN 



although of such influences we have only very meager 

 evidence. 



The energies of the cortical reserves, however 

 released, tend to come to expression in orderly pat- 

 terns depending on the structural organization at the 

 moment of their discharge. So far as these reserves 

 are non-specific or tonic, the patterns of their mani- 

 festation will be determined chiefly by the nature of 

 the subcortical process into which they flow. So far 

 as they are phasic, they are expressions of the activity 

 of certain cortical neurons with a specific structural 

 configuration or "set." And since these cortical con- 

 figurations are largely results of individual or personal 

 experience, these energies may properly be regarded 

 as expressions of the personality of the individual. 



The plasticity of cortical organization (in contrast 

 with the rigidity of the reflex systems) gives to the 

 cortex its efficiency as the arbiter or "decider" of 

 conduct. For a given cortical configuration or "set" 

 of specific neuronic systems may be reactivated in 

 numberless diff"erent situations. I may use my "mem- 

 ory" of Bright Angel Point at the Grand Canyon to 

 draw a map for the guidance of another tourist, as 

 the inspiration of a poem or some other artistic crea- 

 tion, as an illustration of a neurologic process, or as a 

 motive for revisiting the scene at some future time. 



The internally determined eff"orts and volitions 

 are no more myths or figments of unfettered imagina- 

 tion than are the simpler impulses of an insect's 



