http://www.pnas.org/content/pnas/early/2016/06/27/1602413113.abstract.html?…
Functional MRI (fMRI) is 25 years old, yet surprisingly its most common
statistical methods have not been validated using real data. Here, we
used resting-state fMRI data from 499 healthy controls to conduct 3
million task group analyses. Using this null data with different
experimental designs, we estimate the incidence of significant results.
In theory, we should find 5% false positives (for a significance
threshold of 5%), but instead we found that the most common software
packages for fMRI analysis (SPM, FSL, AFNI) can result in false-positive
rates of up to 70%. These results question the validity of some 40,000
fMRI studies and may have a large impact on the interpretation of
neuroimaging results.
They state
"Our principal finding is that the parametric statistical methods work
well, if conservatively, for voxelwise inference, but not for
clusterwise inference. We note that other authors have found RFT
clusterwise inference to be invalid in certain settings under
stationarity (21, 30) and nonstationarity (13, 33). This present work,
however, is the most comprehensive to explore the typical parameters
used in task fMRI for a variety of software tools. Our results are also
corroborated by similar experiments for structural brain analysis (VBM)
(11–13, 39, 40), showing that cluster-based P values are more sensitive
to the statistical assumptions. For voxelwise inference, our results are
consistent with a previous comparison between parametric and
nonparametric methods for fMRI, showing that a nonparametric permutation
test can result in more lenient statistical thresholds while offering
precise control of false positives (13, 41). "
Would be worth discussing at a ynic seminar later in the summer
Gary
--
---------------
Gary Green
York Neuroimaging Centre &
Centre for Hyperpolarisation in Magnetic Resonance
The Biocentre
York Science Park
Innovation Way
Heslington
York
YO10 5NY
tel +44 (0) 1904 435349
fax +44 (0) 1904 435356
mobile +44 (0) 788 191 3004
http://www.ynic.york.ac.ukhttp://www.york.ac.uk/chym/https://www.ynic.york.ac.uk/about-us/people/ggrg
We are aware that many of you who use shared project folders often
encounter the situation where a file in that folder is not accessible to
all members of the group.
We have prepared some guidance on how to avoid this happening. In
addition, we have prepared a (semi) automated procedure that will any
user with access to a group folder to reset the permissions in that
folder so that all files can be shared by all users. This procedure
involves running a script in a command terminal -- a script that resets
the permissions in the entire group directory for all users.
For information, please log into the YNiC wiki with your YNiC login and
view the guidance at:
https://www.ynic.york.ac.uk/docs/ITPages/FilePermissions
--
André
************************************************************************
André Gouws
York Neuroimaging Centre
University of York
The Biocentre
York Science Park
Heslington
YO10 5NY
Tel: +44 (0) 1904 435327
Fax: +44 (0) 1904 435356
Hi All,
Apologies for the short notice; however, would you please be advised
that following further changes to the fire alarm system within the
Biocentre MRI Extension; it will be necessary for me to re-witness the
system in operation on Wednesday 22nd June 2016 between the hours of
16.30pm & 18.30pm approximately.
Due to the nature of the test being that the alarms will need to be
activated; so to avoid anyone leaving the building, on each activation
and it may need to be carried out on a number of occasions; the alarm
will only sound for a short period of time (30 seconds approx). Although
it is anticipated that a smooth operation of the above will be carried
out successfully; should the alarm sound continuously for more than 1
minute, then all precautions need to be taken and all personnel should
leave the building and go to their designated muster point.
It is also assumed that these tests may at some point effect the Fire
Alarm System in CHyM; although these will be alerts rather than full
sounder activation; however, once again, should the alarms sound for
more than 1 minute; the same will apply to the occupants of CHyM and all
personnel should make their way out of the building as appropriate.
In order to assist in making the end user / operatives aware, I will be
affixing notices at the entrance doors of both the Biocentre and CHyM
Buildings advising of this test on Wednesday afternoon (22/6/16).
--
---------------
Gary Green
York Neuroimaging Centre &
Centre for Hyperpolarisation in Magnetic Resonance
The Biocentre
York Science Park
Innovation Way
Heslington
York
YO10 5NY
tel +44 (0) 1904 435349
fax +44 (0) 1904 435356
mobile +44 (0) 788 191 3004
http://www.ynic.york.ac.ukhttp://www.york.ac.uk/chym/https://www.ynic.york.ac.uk/about-us/people/ggrg
There will be two ynic seminars this week.
First we have an extra seminar by Andy Ioannides from the Lab for Human
Brain Dynamiocs, Nicosia.
This seminar will be at noon on Wednesday the 15th in BO20 and the title is
"Understanding sleep and its implications for specific health
conditions" the abstract is below
The second seminar is at the normal time of 4pm on Thursday also in BO20
That seminar will be given by Jody Culham from Western and the title is
"The treachery of images":Why the brain responds differently to real
objects than photos "
Her seminar abstract is
"Psychologists and neuroimagers commonly study perceptual and cognitive
processes using images because of the convenience and ease of
experimental control they provide. However, real objects differ from
pictures in many ways, including the availability and consistency of
depth cues and the potential for interaction. Across a series of
neuroimaging experiments, we have shown that the brain responds
differently to real objects than pictures, both in terms of the level of
activation and the pattern. Now that these results have shown
quantitative and qualitative differences in the way the brain processes
real objects and images, the next step is to determine which aspects of
real objects drive these differences. "
-----------------------------
Andy Ioannides abstract is
"Some 20 years ago, Michel Jouvet, motivated by the early PET scanning
studies of the sleeping brain wrote in the concluding chapter of his
book The paradox of sleep - the story of dreaming “… the majority of
researchers are waiting with bated breath for the results of studies
combining PET scanning, ‘functional’ magnetic resonance imaging (fMRI),
magnetoencephalography and tomographic electroencephalography.” The
developments in the last two decades have fully vindicated this
statement. The talk will first review published work obtained from real
time tomographic analysis of the first whole night MEG recordings of
sleep that focused on changes in regional brain activations and
connectivity between areas related to eye movements and [1] and changes
in regional spectral content in each sleep stage and especially during
Rapid Eye Movement (REM) sleep [2]. The rest of the talk will present
unpublished results from further and more detailed analysis of the same
data. focusing on light sleep (NREM1 and NREM2) and discuss the new
findings in the context of current ideas about the role of K-complexes
and spindles in sleep maintenance and memory consolidation and how these
may relate to pathology. "
References:
[1] Ioannides, A.A., Corsi-Cabrera, M., Fenwick, P.B.C., del Rio
Portilla, Y., Laskaris, N.A., Khurshudyan, A., Theofilou, D., Shibata,
T., Uchida, S., Nakabayashi, T., Kostopoulos, G.K., 2004. MEG tomography
of human cortex and brainstem activity in waking and REM sleep saccades.
Cereb. Cortex 14, 56–72.
[2] Ioannides, A.A., Kostopoulos, G.K., Liu, L., Fenwick, P.B.C., 2009.
MEG identifies dorsal medial brain activations during sleep. Neuroimage
44, 455–468. doi:10.1016/j.neuroimage.2008.09.030
--
---------------
Gary Green
York Neuroimaging Centre &
Centre for Hyperpolarisation in Magnetic Resonance
The Biocentre
York Science Park
Innovation Way
Heslington
York
YO10 5NY
tel +44 (0) 1904 435349
fax +44 (0) 1904 435356
mobile +44 (0) 788 191 3004
http://www.ynic.york.ac.ukhttp://www.york.ac.uk/chym/https://www.ynic.york.ac.uk/about-us/people/ggrg
Dear users,
Two talks will be given today at 4pm in B020.
Mladen Sormaz will help us understand the contents of this thoughts on
resting state brains in a talk entitled:
‘Understanding the content of thought’
Charlotte Murphy will then dazzle us with her eloquence and sagacity via
a talk entitled:
‘Distinguishing stimulus independence from representation’
As always there will be refreshments in C Block reception after the talks.
We look forward to seeing you there.
All the best,
Junior
--
Junior Whiteley
York Neuroimaging Centre
junior.whiteley(a)ynic.york.ac.uk
Please can I remind all TMS operators and anyone using the TMS lab to take
due care when using and putting away the TMS coils. Today we have found
that four of the tracking spheres on the coil trackers needed replacing.
The retroreflective surface on the spheres is delicate and will wear if
touched or knocked. This will lead to inaccurate tracking for your
experiments as the centre of the sphere will be misestimated by the
Brainsight system. Further, this suggests that the coil trackers are
getting knocked which is not ideal as these are delicate, precision
instruments.
It is important that you check the spheres on the coil trackers each time
you run an experiment. If you find they are damaged please talk to Andre or
myself. We can then help you replace the markers and order more as required
to make sure experiments can continue to run smoothly
I have attached a photo of one of the damaged spheres from today for
reference
Thanks
Bruce
[image: Inline images 1]
Dear All,
I am pleased to announce that Department of Psychology will be hosting the
Computational Modelling of the Visual System symposium as a part of the
NextGenVis Marie Skłodowska-Curie Innovative Training Network. The
symposium is scheduled for Saturday, 17th September 2016 and will take
place at Kings Manor, York.
Keynote speakers for the symposium are Aviv Mezer (The Hebrew University,
IL), Bob Dougherty (Stanford, USA) and Geoff Aguirre (University
of Pennsylvania, USA).
*Registration:*
If you would like to register to attend there is a fee of £32 - this fee
covers symposium registration, tea and coffee, and lunch. If you wish to
pay with your M-Code budgets, please note that it will be attributed to the
*next* financial year.
If you would like to register, please send your name to
marc.himmelberg(a)york.ac.uk. You will be required to send your work order or
M-Code to finance at the start of August. Alternatively, cheques and cash
are acceptable.
*The registration deadline is 30th June.*
Best,
Marc and Barbara
--
Marc Himmelberg
PhD Student
PS/C224, Department of Psychology
University of York
York, YO10 5DD
UK
Dear Users
YNiC used to have a set of headcaps for use with EEG. These were of
different sizes for children up to adults. The complete set has been
removed from the box in the MEG area that is labelled for these caps.
I am sure that they were borrowed for a perfectly good scientific reason
but we would like them back. No questions will be asked
Gary
--
---------------
Gary Green
York Neuroimaging Centre &
Centre for Hyperpolarisation in Magnetic Resonance
The Biocentre
York Science Park
Innovation Way
Heslington
York
YO10 5NY
tel +44 (0) 1904 435349
fax +44 (0) 1904 435356
mobile +44 (0) 788 191 3004
http://www.ynic.york.ac.ukhttp://www.york.ac.uk/chym/https://www.ynic.york.ac.uk/about-us/people/ggrg
Hi All,
Apologies for the short notice; however, would you please be advised
that the witnessing of the fire alarm system within the YNiC MRI
Extension has been re-scheduled for Thursday 2nd June 2016 between the
hours of 16.00pm & 18.30pm approximately.
Due to the nature of the test being that the alarms will need to be
activated; so to avoid anyone leaving the building, on each activation
and it may need to be carried out on a number of occasions; the alarm
will only sound for a short period of time (30 seconds approx). Although
it is anticipated that a smooth operation of the above will be carried
out successfully; should the alarm sound continuously for more than 1
minute, then all precautions need to be taken and all personnel should
leave the building and go to their designated muster point.
It is also assumed that these tests will at some point effect the Fire
Alarm System in CHyM; although these will be alerts rather than full
sounder activation; however, once again, should the alarms sound for
more than 1 minute; the same will apply to the occupants of CHyM and all
personnel should make their way out of the building as appropriate.
In order to assist in making the end user / operatives aware, We will be
affixing notices at the entrance doors of both the Biocentre and CHyM
Buildings advising of this test on Thursday afternoon (2/6/16).
Gary Green