2. • Consciousness is often conceptualized as en-
compassing two cardinal elements (Laureys
2005):
– wakefulness: refer to the level of consciousness
– Awareness: refer to its contents

4. Introduction
• disorders of consciousness (DOC)(Monti. 2012)
– Coma: lack both awareness and wakefulness
– Vegetative State(VS): basic vegetative nervous
functions are preserved, but in the absence of any
sensation and thought
– Minimally Conscious State(MCS): not only to be
wakeful (like vegetative-state patients) but also exhibit
inconsistent but reproducible signs of awareness of
themselves or their surroundings
– locked-in syndrome(LIS): both awake and aware but
are either unable to produce any motor response

5. Introduction
• self-referential processing in DOC:
– Di et al. (2007): five out of seven VS patients exhibited primary
auditory activity in response to their own name. In addition, in
two VS patients (and all MCS patients),activations in higher-level
posterior temporal cortices were also detected.
– Qin et al. (2010) reported significant activations for six out of
seven VS patients in one or more of three medial prefrontal
regions previously linked to processing self-related stimuli
• Resting state in DOC:
– alterations in cortical midline structures, abnormally low
functional connectivity (Boly et al., 2009; Cauda et al., 2009;
Vanhaudenhuyse et al., 2010) and effective connectivity
(Rosanova et al., 2012).

6. Questions
• 1) In DOC, the temporal dynamics of resting state
activity, such as the amplitude of low-frequency
fluctuations (ALFF)(Kannurpatti and Biswal, 2008;
Zang et al., 2007) and standard deviation of
neural activity changes across time (Garrett et al.,
2011), remain to be thoroughly investigated.
Importantly, the functional implications of
abnormalities in the resting state remain unclear
• 2) It is unclear how to relate self-referential
processing, resting state activity and
consciousness in DOC patients.

7. Hypothesis and Aim
• (1) the neural response to self-referential stimuli in the
midline regions would be present though abnormally
reduced in DOC patients; a particularly strong link
between neural responses in midline brain regions and
the level of consciousness,
• (2) abnormal brain responses while processing self-
referential tasks may be related to impairments not
only in the spatial domain but also with temporal
abnormalities in neuronal measures of resting state
activity, e.g. lower ALFF and standard deviation within
the midline regions

8. Materials and Methods
• Participants and patients
– 12 healthy control subjects
– 11 patients (six VS and five MCS)

9. fMRI scan procedure
Resting
6min
task
8’8’’
task
8’8’’
task
8’8’’
task
8’8’’
T1
Trial Trial
8s,10s,12s
20 self-referential & 20 non-self-referential,
delivered in a pseudo-random order.

10. Results
• Behavioral data: from longitudinal behavioral
assessments (CRS-R)
– VS5 and VS6 exhibited clinical improvement and
were classified as MCS two months after the fMRI
study
– Patients MCS3 and MCS4 recovered 2 months
after the fMRI, and were able to repeatedly follow
a command to move and verbally answer to their
names.

12. fMRI Results

14. • healthy group > DOC patient group

18. Conclusion
• DOC patients exhibit reduced cortical responses
compared with healthy controls during active
self-referential processing in anterior and
posterior midline regions.
• The magnitude of cortical responses in the
anterior midline regions (e.g. PACC) was
significantly correlated with DOC patients’ degree
of consciousness.
• PACC displayed major resting-state abnormalities
as manifested by reduced ALFF, FC, and SD of
signal changes.