CHAPTER LXIV 



Attention, consciousness, sleep and wakefulness 



DONALD B. LINDSLEY 



Departments of Psychology and Physiology, University of California, 



Los Angeles, California 



CHAPTER CONTENTS 



Neurophysiological Mechanisms 



Early Neurophysiological Concepts of Sleep and Wakefulness 

 Origins of the Ascending Reticular Activating System Con- 

 cept 

 Hypothalamic-cortical discharge concept 

 Origins and Characteristics of the Diffuse Thalamic Pro- 

 jection System 

 ARAS and DTPS Arousal and Alerting Effects 

 Interaction of ARAS, DTPS, STPS and Neocortex 



Inhibition and facilitation via the reticular formation 

 Cortical Interaction of Specific and Unspecilic Influences 



Microelectrodc studies 

 'Habituation' and Attention 

 The Electroencephalogram in Sleep and Wakefulness 

 Characteristics of the BEG in Wakefulness 

 Characteristics of the EEC in Sleep 

 The Sleep-Wakefulness Continuum 

 EEG and Eye Movement Studies of Dreaming During 



Sleep 

 Is Learning During Sleep Possible? 

 Consciousness, Attention, Hypnosis and the EEG 



Consciousness 

 Consciousness and EEG Characteristics 

 Induced Physiological Changes 



Seizure Patterns with Modilication of Consciousness 

 Temporal Course of Consciousness 

 Attention and the EEG 

 EEG in Hypnosis 

 Summary 



the terms attention, consciousness, sleep and wake- 

 fulness are a part of our everyday language, and we 

 seem to understand, at least in a general way, what 

 is meant by them. As scientific investigators, how- 

 ever, we are often loathe to attempt a definition of 

 these terms because there are too many unknown or 

 variant conditions involved, or because to limit one- 

 self to a given criterion, or even a set of criteria, may 

 not account for all examples. 



We are fully aware from our own experiences, as 

 well as those reported by others, that an attentive 

 set or posture toward a given object in the environ- 

 ment docs not always result in awareness and per- 

 ception of the object. Furthermore, experiments 

 have shown that a pre-established set or intention to 

 respond as quickk .is possible to the onset of a specific 

 stimulus does not lead to uniform reaction times, 

 there may be wide variations in response lo successive 

 stimuli. Thus, due apparently to spontaneous fluctua- 

 tions of some process controlling attention, or due to 

 distractions produced by competing stimuli, ideas 

 and thoughts of past experience, one may look direct 1\ 

 .it .111 object and not see it, or overlook the cue to 

 respond to a given stimulus with resulting delay or 

 complete absence of response. 



The following are .1 lew examples ol some of the 

 vagaries oi attention in which the behavioral attitude 

 orset in.i\ belie the actual attentional and perceptual 

 attitude. The astronomer waiting lor the exact instanl 

 of a stellar transit across his telescope may miss \\ 

 due to a lapse of attention or daydreaming. The radar 

 operator waiting for the unusual and unexpected 

 'blip' on his radar screen may not be reach' to report 

 it when it appears among other signals, due to 

 peripheral sensory or central ideational distractions. 

 The sonar operator listening for the special 'ping' of 

 the enemy submarine by sound-echo return may be- 

 come habituated to the repeated sounds and noises 

 and miss the critical signal. 



Thus the temporal course of consciousness or aware- 

 ness may show many vicissitudes. Often these can 

 be determined and assessed by introspection or sub- 

 jective report after the fact, but with possible loss of 

 information and sequence because of fallibility result- 

 ing from attempting to 'observe' both external and 

 internal events. If we require an immediate verbal 



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