Monday, May 22, 2017
Monday, April 24, 2017
Monday, April 17, 2017
Atlantis platform and it now forms a key way of differentiating or sharpening results where there experimenter is worried that the changes or effects between control and experimental groups might be small. This is extremely valuable in cases where identifying the differences between control and test animals in crucial and worth a small additional investment. Things to check for in the modern Atlantis platform include (1) silent operation (which is often not the case with pump driven pneumatic ones - which give a directional auditory cue from the pump motor, (2) complete electrical isolation from the mains (which is essential given that the experimenter is operating in water) and (3) the availability of Atlantis arrays so that the platform does not have to be repositioned between trials, but instead the array comprises four different platforms any one of which can be operated separately by the controller. The best systems today are the Neodymium Iron Boron actuators (AKA "Neo" or NdFeB) which actually hold the platform in place with no current flow and only need a current pulse of a few milliseconds to release. These are safer, more quiet and much faster in operation and represent a really worthwhile move forward from systems of five years ago or more.
|Rats trained with the Atlantis platform show improved spatial localization of search |
Figure from Spooner et al 1995
Wednesday, April 12, 2017
Sandstrom et al 1998), but if you've experienced actual virtual reality versions rather than ersatz versions you'll appreciate that there is a huge difference which can be quantified in terms of hippocampal theta activity (Cornwell et al 2008). There is a good description of why these differences are seen in the Behavioral Neuroscience Tasks in Virtual Reality pages as well as explanations of why what you thought was Virtual Reality in some experiments really isn't and often elicits quite different search strategies from those found both in reality and higher quality representations.
Wednesday, June 22, 2016
A range of USB cameras can be used with the HVS Image video tracking and analysis software, including the HVS Image camera supplied in the accessories kit available from the company, and off-the-shelf web cams you can buy from PC stores or at low cost from eBay and Amazon.
Which camera suits you best will depend on your experimental set-up and whether you need to cater for more than one type of experiment.
If you want a versatile camera that can be used at different distances from the tracking area and for tracking area of different dimensions, the HVS Image camera is the answer. This has:
- wide angle lens for use with Morris Water Maze, and other lenses for smaller mazes and arenas;
- manual focus allowing you to focus at the tracking surface, so there is no issue of an auto-focus taking time to adjust when the subject enters the tracking area - it will already be in focus;
- threaded mounting point for fixing the camera securely in place with the accompanying ceiling mount or other standard mount.
The HVS Image camera comes with a 30 foot USB boosted extension lead, lenses including a wide angle and a varifocal zoom, ceiling mount and long range wireless remote for starting trials from the pool, maze or arena.
Other cameras that can be used include the low cost Microsoft LifeCams such as the VX-800, which you can pick up for around $10, or the Logitech C920. Watch out for the following if choosing your own camera:
- Not all web cams have a threaded mounting point, so you may need another way to hold it in place, such as duct tape;
- Most web cams are auto-focus, so run some tests to make sure that the image is clear enough for the subject to be tracked right from the start of the trial;
- The angle of view stated in web cam specs is usually the diagonal, so be careful to ensure you get one that will fit your tracking area into the image;
- Most web cams don't have a wide enough angle to fit a large water maze, unless you have a high ceiling, so you may need the HVS Image camera. HVS Image are always happy to advise.