from Section I - Historical context
Published online by Cambridge University Press: 07 September 2011
Summary
Among sleep stages, awakenings from rapid eye movement (REM) sleep produce the greatest number and reported intensity of dream reports. Dreaming is a conscious state that lacks the insight and cognitive control typical of healthy waking but allows the remarkable emergence of coherent narrative, vivid visual imagery, strong emotion, and sometimes never-before-experienced elements. Similar to waking, ascending activation from the brain stem, basal forebrain, and diencephalon produces the brain-activated state of REM and its associated dream consciousness. However, in REM, the neuromodulatory influences producing this arousal are largely cholinergic and lack the aminergic activation accompanying cholinergic modulation in waking. Positron emission tomography (PET) studies have shown that in REM vs. waking, lateral cortical areas subserving cognitive control and higher order cognition are relatively less activated whereas midline anterior limbic cortical and subcortical structures are equally or more active. Such differences in neuromodulation and regional brain activity help shed light on the neural processes producing phenomenological differences between dream and waking consciousness. Advances in neuroimaging techniques including functional magnetic resonance imaging (fMRI) and electromagnetic source localization are providing new details on the tonic conditions and phasic neural events during REM that may contribute to dream experience.
To save this book to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.