Time to wave goodbye to phase scrambling

skatesBobby Stojanoski’s paper came out in the Journal of Vision this week. When investigating the recognition of visual objects with neuroimaging, it is often necessary to have control stimuli matched in visual features, but lacking meaning. Using the HMAX model of early visual processing, we show that three ways commonly used to create control stimuli, phase-, box- and texture- scrambling are poorly matched, even at the earliest stages of the visual system. We propose an alternative using diffeomorphic transformations, that yields visually well matched control stimuli while removing meaning. wavegoodbyehmax

Unlike other scrambling methods, diffeomorphic stimuli were found to yield a similar overall level of activity in the simulated neurons of the HMAX model, with a pattern and a distribution for objects and scrambled objects that could not be distinguished by a linear discriminant classifier.

Hitchcock probes consciousness

title_thumbnail600The lab is excited by the response to our method of detecting consciousness through the brain’s response to watching an Alfred Hitchcock short film. It has been featured up by the scientific media (Nature, Science), television (CBC, CTV), the press (The Times, Globe and Mail, London Free Press, Macleans, The Verge), in blogs (iflscience.org) and on social media.

Frequently asked questions

Why Hitchcock?
It is important for our method that each moment in the film evokes similar thoughts and emotions in different people. Good film directors are skilled at leading the minds of their viewers in a particular direction – and Hitchcock is The Master. This means that at the time in the film when one person is drawn in by the suspense, and their brain activity peaks, others will be too.

Why suspense?
In suspense films, in the most tense parts of the movie, there isn’t a great deal of visual motion or activity on the screen. This means that we can separate the brain’s response to tension and its response to visual events.  Furthermore, for the neuroimaging to be sensitive, we need some parts of the movie that are exciting and elicit strong brain activity, and other parts that are calm. Suspense movies have this pattern.

Why Bang! You’re dead.
This movie was recommended by Uri Hasson. We needed a shorter version for scanning in patients, and so I edited it from 30 to 8 minutes long, while keeping the story broadly intact. This was my crime, and so I’m sorry, Alfred.

Who were the vegetative patients?
jeff_tremblay_macleansThe male patient, who showed a conscious response to the movie, was Jeff Tremblay, who is 35 years old, and has been unable to respond since suffering a cardiac arrest after being kicked in the chest in August 1997. You may read more about the family in Macleans. The female patient, who did not show evidence of consciousness, was 20 years old, and has chosen to remain anonymous.

lori_press_2cHow did you separate different brain networks?
In a group of 12 healthy adults, we used a method called Independent Components Analysis (ICA) to find brain networks that showed statistically independent patterns of change over time. As all of the people were watching the same movie (and provided Alfred has done his job) then we expected them to show the same time-course of brain activity (see different colours, to the left). We were able to use this additional information by using a method for called Tensor Independent Components Analysis, as implemented in software from Oxford University.

Reference

Naci, L., Cusack, R., Anello, M., Owen A.M. (in press). A common neural code for similar conscious experiences in different individuals. Proceedings of the National Academy of Sciences

Welcome to the lab

Welcome to Michelle Tran and Jordynne Ropat, who’ve joined the lab as Master’s students, and to Claire Chambers, a postdoctoral researcher with funding from the European Union’s Erasmus Mundus Student Exchange Network in Auditory Cognitive Neuroscience.

Lab photo September 2014

Clockwise from top left: Conor Wild, Annika Linke, Bobby Stojanoski, Jordynne Ropat, Jacob Matthews, Laura Cabral, Rhodri Cusack, Hester Duffy, Michelle Tran, Leire Zubiaurre Elorza, Claire Chambers

Little brains symposium at Society for Research in Child Development

Thanks to everyone that attended the “Little Brains” symposium at the Society for Research in Child Development‘s Fall meeting on methodology. And thank you to Charlotte Herzmann, who organized the symposium, and to the other speakers Christopher Smyser (Washington University School of Medicine), Elizabeth Redcay (University of Maryland) and John Flournoy (University of Oregon).

Awards

We’d like to thank a number of organizations for supporting our work this summer:

  • The Children’s Health Research Institute and Research Western for seed funding for new projects
  • The CIHR (for supporting Charlotte Herzmann at the Human Brain Mapping conference), the International Society for Magnetic Resonance in Medicine (for supporting Conor Wild), and the International Society for Developmental Neuroscience (for supporting Leire Zubiaurre Elorza), all travel awards.
  • CIHR for a studentship (to Laura Cabral).

Cusacklab hits #OHBM2014

If you’re at Human Brain Mapping in Hamburg, please come and see the lab’s latest work. Or leave a comment/ send me an email if you’d like a copy.

Poster 1715. Whole Brain Dynamic Network Analysis in Real-time During Video Viewing. Jingyun Chen, Jinhui Qin, Rhodri Cusack, Mark Daley
A collaboration with IBM Canada, in which we’ve streamed MRI data into a cloud-based supercomputer for real-time whole brain network analysis.

Poster 3638. Automatic analysis (aa) pipelines: new features for large, multimodal datasets. Tibor Auer, Alejandro Vicente-Grabovetsky, Daniel Mitchell, Conor Wild, Annika Linke, Jonathan Peelle, Rhodri Cusack
Describes the latest innovations in our aa software, which is a collaboration with the MRC in Cambridge UK, the Donders Institute of Cognitive Neuroscience in the Netherlands, and Washington St Louis, USA. See also www.github.com/rhodricusack/automaticanalysis

Poster 4372. Hitchcock probes changes in cortical auditory processing through the lifespan Charlotte Herzmann, Leire Zubiaurre-Elorza, Cam-CAN, Rhodri Cusack.

Poster 4385. Beyond the Resting State: Age Differences in Neural Networks Identified during Naturalistic Viewing. Karen Campbell, Meredith Shafto, Paul Wright, Kamen Tsvetanov, Rhodri Cusack, Cam-CAN, Lorraine K. Tyler.
Some of our first exciting results from the Cam CAN study of cortical changes through the lifespan with MRI from 700 participants aged 18-88 years.

Congratulations to Laura Cabral

The lab would like to congratulate Laura Cabral, who won a CIHR Canada Graduate Scholarship to support her Masters degree. This is one of just 15 awarded by the Canadian Institute of Health Research at Western, and an excellent achievement in a rigorous competition. Laura will  study the development of the visual system during the first year of postnatal life. She will initially study typically developing infants, and later infants with perinatal brain injury, with the goal of detecting visual impairments earlier, so that timely interventions can be made.

We’d also like to thank CIHR for this award.

Vacancy: Research Nurse – Paediatric, Neonatal/Perinatal

We seek a Research Nurse to attend MRI scanning sessions of infants under one year old. Your main roles will be: assisting with the care of the infant during the scan; communicating with parents regarding the scanning process; and answering/referring questions parents may have.

The scanning sessions will support a project to develop assessments of the brain using neuroimaging. At present, it is difficult to predict what the consequences of early brain abnormalities will be, and many infants with brain injury develop without any symptoms, while others have cognitive or behavioural challenges later in life. Our project aims to develop new assessments of brain functioning and development using neuroimaging with fMRI.

Some infants will be NICU graduates with a history of brain injury, and others will be matched controls recruited from the maternity ward. During the scanning sessions you will assist in identifying situations where the infant needs attention, and in the event of an unexpected emergency, when medical assistance should be called.

It is our goal to have approximately two three hour slots per week at a regular time, with some or all in the evening or at the weekend. However, some flexibility (to allow for MRI scanner and patient availability) would be helpful, and this schedule may need to be adjusted depending on recruitment success.

The postholder will join a multidisciplinary team of scientists at Western’s Brain and Mind Institute, and physicians and staff at London Health Sciences Centre. Scanning will take place at the state-of-the-art facilities at the Centre for Functional and Metabolic Mapping at the Robarts Research Institute.

Rate of Pay: $40/hour

Hours of Work: Estimated at 6 hours/week

Start date: Jan 2014

QUALIFICATIONS:

  • Current Certificate of Registration with the College of Nurses of Ontario
  • Current Basic Life Support for Healthcare Providers course: BLS-HCP(C)
  • ENC (C), ACLS, TNCC, and PALS certification preferred
  • Monitoring experience (i.e. saturation, ECG)
  • Well-developed patient assessment, planning, intervention and evaluation skills
  • Thorough understanding and commitment to Patient and Family Centred Care principles and ability to use in practice
  • Ability to understand the feelings, concerns and needs of other people, demonstrate care and interest towards them and establish and maintain productive relationships
  • Ability to demonstrate an optimistic disposition toward new experiences and change in general
  • Demonstrated knowledge of and commitment to patient and staff safety
  • Demonstrated ability to attend work on a regular basis
  • Basic understanding of MRI safety
  • Research experience preferred

To apply, please send a cover letter and CV to Rhodri Cusack at vacancies@cusacklab.org
We will begin considering applications on Dec 3.