Confusion of Dreaming with Reality in Narcolepsy

Narcolepsy is a neurological disorder characterized by the intrusion of rapid
eye movement sleep into the waking state. Hallmark symptoms of the disorder
include daytime sleep attacks, cataplexy, sleep paralysis, and vivid
hallucinations at sleep onset. Although memory impairment is not typically
observed in narcoleptics when standardized tests are employed, it is common for
patients to present with subjective memory complaints. Clinical observations
suggest that these patients may frequently experience one particularly
intriguing type of memory problem, in which they mistakenly think that an event
that occurred in a dream might have actually happened in real life. Although
such experiences have been described in a handful of case studies, to date
there have been no systematic descriptions of the incidence of this memory
complaint in the narcoleptic population, nor of the qualitative characteristics
of these dream/reality confusions.
These confusional experiences may represent a failure of *reality
monitoring*, a psychological mechanism by which we distinguish thought and
fantasy from actual events, resulting in confusion about the origin and reality
of a past experience. Studying these instances of dream/reality confusion in
narcoleptic patients may give us clues to the normal functioning of memory
systems in the human brain. Accumulating evidence now demonstrates that sleep
is integrally involved in the processing and retention of memories across
time. We hypothesize that the sleep-related dysfunctions characteristic of
narcolepsy may explain the unique memory complaint of confusing dreams with
reality. Specifically, abnormal hippocampal-cortical communication dynamics
during REM (rapid eye movement) sleep could cause patients suffering from
narcolepsy to encode the experience of a dream in a manner very similar to how
waking experiences are stored in memory, thus leading to confusion about the
origin of the memory.
The confusion of dream experiences with reality is also of potential
interest from a clinical perspective. It has long been reported that
narcoleptic patients complain of memory problems, though objective tests of
memory performance have failed to reveal any consistent deficits. It may be
that subjective memory complaints in narcolepsy arise from a unique type of
memory dysfunction to which standard testing instruments are insensitive. In
this context, the aforementioned anecdotal reports and case studies describing
confusion of dreaming with reality in narcolepsy are of particular interest. It
has been established that confusion of dreaming with reality can occur in the
normal population (i.e. Kemp & Burt, Memory, 2006). However, we hypothesize
that the incidence and severity of this experience is much greater in the
narcoleptic population than in normals. Exploring these memory *source
confusions* may allow us to better understand the nature of memory impairment
in this disorder.

The goals of the present study, therefore, are twofold:
a) To estimate the incidence of dream/reality confusions in the narcoleptic
population, relative to healthy controls
b) To provide a comprehensive description of the characteristics of these
confusional instances

Towards these ends, we plan to conduct a two-part interview study, in which
patients and healthy controls suffering from this particular memory complaint
will first be identified through a telephone screening process, and then will
come in to the laboratory for a more extensive face-to-face interview session.
Through this research, we hope to attain a better understanding of the nature
of memory impairment in narcolepsy, as well as the more general relationship
between memory processes and sleep.

Procedures/Instruments
This is a two-part interview study. During the initial phase, narcoleptic
patients and healthy controls will participate in a short (approx. 15-20 min)
telephone interview (see section C for recruitment techniques and selection
criteria). Based on participants* responses during this phone interview,
subjects may be invited to come to the laboratory for a longer (approx. 45 min)
interview session, during which further details about these confusional
instances would be elicited.

Part I
The initial phase will consist of a brief (approx. 15-20 min) telephone
interview, in which participants will be queried about the general
characteristics of their sleep and dreams, and will be asked whether they have
ever been unsure if an event actually occurred, or was only experienced in a
dream. The phone interview will also include administration of two short
questionnaires: The Boundary Questionnaire (Hartmann, 1989), and the
Prospective/Retrospective Memory Questionnaire (Smith et al., 2000).

Part II
During the second part of the study, those who responded that they have been
confused in the past about whether an event was dreamed or real will be asked
to come to the laboratory for an in-depth interview. During the face-to-face
interview, participants will be asked to provide detailed information on these
experiences. This interview will be tape-recorded, in order to facilitate the
later coding and analysis of the data.

Minimal risk is involved in this interview-based protocol. If participants
recall dreams or waking experiences during the study that are embarrassing or
socially unacceptable, they may not feel comfortable reporting this material.
Accordingly, subjects will be specifically instructed that they are not
obligated to describe any dreams or experiences that they do not feel
comfortable sharing. These minimal risks to participants are deemed to be
acceptable in light of the modest educational benefits provided to
participants, combined with the potentially substantial benefits of the
knowledge gained through this research to society as a whole.