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SCIENCE & CONSCIOUSNESS REVIEW
SCI-CON.ORG NEWSLETTER
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April 6, 2004

ARTICLES IN THIS ISSUE
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1. SCR Original: Peripheral drift illusion
2. Featured Research - TMS Study of ventral projections from V1 with
implications for finding the NCC
3. Featured Research - Auditory Processing in brain injured patients
reveals differences between Minimally Conscious State and Persistent
Vegetative State
4. Featured Research - Avoidance of obstacles in the absence of visual
awareness
5. Brain Activation May Explain PTSD Flashbacks
6. News - Memories are harder to forget than currently thought
7. Obituary for Donald Griffin; 3/Aug/1915 - 7/Nov/2003
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1. Peripheral drift illusion
by Thomas Z. Ramsøy
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Illusions always seem to capture our attention, and they strike us as
strange and interesting. However, we often do not think of these odd
sensations as mere curiosities. In spite of this, a growing literature
on illusions points to the fact that these sensations are not only
interesting in themselves; they are potent sources for insight into
normal vision.

Read More: http://www.sci-con.org/articles/20040401.html
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2. TMS Study of ventral projections from V1 with implications for
finding the NCC
Overgaard M, Nielsen JF, Fuglsang-Frederiksen A
University of Aarhus, Denmark
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The study of subliminal perception in normal and brain lesioned
subjects has long been of interest to scholars studying the neural
mechanisms behind conscious vision. Using brief durations and a
developed methodology of introspective reporting, we present an
experiment with visual stimuli that gives rise to little or no
subliminal perception under normal viewing conditions. Coupled with
transcranial magnetic stimulation, however, we find a dissociation
between correctness and conscious awareness. Furthermore, we find
support for the hypothesis that the ventral projection streams from V1
are necessary for visual consciousness.

Read More: http://tinyurl.com/2x34l [ScienceDirect.com]
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3. Auditory processing in severely brain injured patients: Differences
between the minimally conscious state and persistent vegetative state.
Mélanie Boly et al.
Cyclotron Research Center, Belgium
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Background: The minimally conscious state (MCS) is a recently defined
clinical condition; it differs from the persistent vegetative state
(PVS) by the presence of inconsistent, but clearly discernible,
behavioral evidence of consciousness.

Results: In both patients in an MCS and the healthy controls, auditory
stimulation activated bilateral superior temporal gyri (Brodmann areas
41, 42, and 22). In patients in a PVS, the activation was restricted
to Brodmann areas 41 and 42 bilaterally. We also showed that, compared
with patients in a PVS, patients in an MCS demonstrated a stronger
functional connectivity between the secondary auditory cortex and
temporal and prefrontal association cortices.

Conclusion: Although assumptions about the level of consciousness in
severely brain injured patients are difficult to make, our findings
suggest that the cerebral activity observed in patients in an MCS is
more likely to lead to higher-order integrative processes, thought to
be necessary for the gain of conscious auditory perception.

Read More: http://tinyurl.com/2hlca [JAMA Journal Archives]
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4. Avoidance of obstacles in the absence of visual awareness
R. McIntosh; K. McClements; I. Schindler
University of Durham, UK
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The spatial character of our reaching movements is extremely sensitive
to potential obstacles in the workspace. We recently found that this
sensitivity was retained by most patients with left visual neglect
when reaching between two objects, despite the fact that they tended
to ignore the leftward object when asked to bisect the space between
them. This raises the possibility that obstacle avoidance does not
require a conscious awareness of the obstacle avoided. We have now
tested this hypothesis in a patient with visual extinction following
right temporoparietal damage. Extinction is an attentional disorder in
which patients fail to report stimuli on the side of space opposite a
brain lesion under conditions of bilateral stimulation. Our patient
avoided obstacles during reaching, to exactly the same degree,
regardless of whether he was able to report their presence. This
implicit processing of object location, which may depend on spared
superior parietal-lobe pathways, demonstrates that conscious
awareness is not necessary for normal obstacle avoidance.

Read More: http://tinyurl.com/24t3o [IngentaSelect.com]
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5. Brain Activation May Explain PTSD Flashbacks
American Psychiatric Association News
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PTSD subjects appear to process traumatic memories differently from
subjects without PTSD. This difference may help explain why people
with PTSD tend to recall traumatic memories as visual flashbacks,
while those without the disorder recall verbal narratives.

When persons with posttraumatic stress disorder remember trauma, right
areas of their brains tend to be activated, whereas when^ individuals
without PTSD remember trauma, left areas of their^ brains are apt to
be aroused, according to a study reported^ in the January /American
Journal of Psychiatry.

Read More: http://pn.psychiatryonline.org/cgi/cont
ent/full/39/6/61?etoc
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6. Memories are harder to forget than currently thought
EurekaAlert
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Previous studies in rodents had shown that the process of encoding a
memory could be blocked by the use of a protein synthesis inhibitor
called anisomycin. Experiments with anisomycin helped lead to the
acceptance of a theory in which a learned behavior is consolidated
into a stored form and that then enters a 'labile' - or adaptable -
state when it is recalled. According to these previous studies, the
act of putting a labile memory back into storage involves a
reconsolidation process identical to the one used to store the memory
initially. Indeed, experiments showed that anisomycin could make a
mouse forget a memory if it were given anisomycin directly after
remembering an event.

In the PNAS study, however, the Penn researchers showed that
disruption of a "re-remembered" memory was not permanent.

"When we looked at mice 21 days after they were treated with
anisomycin to block the reconsolidation of a memory, we showed that
they could, in fact, remember the original learned behavior," Lattal
said. "If you use the anisomycin, you can destroy a 'fresh' memory,
but the 'forgetting' effect of anisomycin on an established memory is
only temporary, at best."

Read More:
http://www.eurekalert.org/pub_releases/2004-03/uop-mah031504.php
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7. Obituary for Donald Griffin; 3/Aug/1915 - 7/Nov/2003
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We announce with great regret the passing of Donald R. Griffin, the
foremost pioneer in modern times of scientific research on animal
consciousness. Griffin broke a scientific taboo by suggesting that
animals might have the capacity to think and reason, and that
scientists should study these mental processes. This gave rise to the
field known as cognitive ethology and, in general, animal sentience.

Born in Southampton, N.Y., Dr. Griffin received his bachelor's,
master's, and doctorate degrees from Harvard and worked there from
1953 to 1965. He worked at Rockefeller University from 1965 to 1986.
His wife, Jocelyn Crane, died in 1998. He leaves two daughters, Janet
Abbott of Arlington, and Margaret Griffin of Montreal, and a son,
John, of Boston.

Read More: http://www.animalsentience.com/features/donald_griffin.htm
http://www.whoi.edu/media/obits/d_griffin.html
http://tinyurl.com/ywa5e [Boston.com]
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