Reflexive and orienting properties of REM sleep dreaming and eye movements

In this manuscript Hobson et al. propose a model exploring qualitative diff erences between the three states of consciousness, waking, NREM sleep, and REM sleep, in teens of state-related brain activity. The model consists of three factors, each of which varies along a continuum, creating a three-dim ensional space: activation (A), information flow (I), and mode of informati on processing (M). Hobson has described these factors previously (1990; 199 2a). Two of the dimensions, activation laid modulation, deal directly with subcortical influences upon cortical structures - the reticular activation system, with regard to the activation dimension and the locus coeruleus and the pontine raphe neuclei, with regard to the modulation dimension. The fo cus of this review is a further exploration of the interaction between drea ming and the cortical and subcortical structures relevant to REM sleep eye movements.