EthoVision XT makes data collection easy and straightforward, but of course you will also need to analyze this data. EthoVision XT helps you out in that department, too. It has powerful tools for data selection, visualization, and analysis.
“EthoVision XT has allowed our group to significantly cut down the time spent analyzing behavior”
Dr. O. Fernández Gayol | Universitat Autònoma de Barcelona
Visualizing your data is an important step in analysis, and can be done in several ways and at several points in time. While plotting your data in graphs is useful after selection and analysis, visualization of the tracks superimposed on the video file (integrated visualization) is helpful in the beginning steps of analysis, because it gives you a good feel for the data. Additionally, when you are interested in certain behaviors such as body elongation or mobility, use the visualization function to fine-tune the thresholds for these behaviors. You can also view all tracks side by side and even export these images at high resolution.
This part of the software also has a built-in screen recording tool, allowing you to make a video of the integrated visualization which you can use for presentations.
EthoVision XT’s data selection tools let you evaluate certain subsets of each trial. Selecting the data, for example, in which animals received a specific treatment allows you to analyze only those data and ignore the rest. Or nest your data on time, zone or a behavioral or physiological state.
Data selection is very intuitive to set up, using blocks that, for example, contain "filters". You can copy-paste, and adjust these blocks as needed, for an efficient workflow.
In any tracking system, there are three sources of noise that potentially skew the values of dependent variables such as distance moved or velocity; system noise, outliers, and small movements of the animal (body wobble). EthoVision XT includes tools to smooth out your data.
The number of parameters that can be used for analysis is substantial, including trial duration, in zone, distance to zone, distance to zone border, distance moved, velocity, heading, turn angle, angular velocity, mobility, proximity, rotations, elongation, body angle, acceleration, etc. Statistics include mean, variance, standard deviation, standard error, minimum, maximum, sum, total, number of samples, and more.
For example: use elongation, mobility, and head direction parameters when you are performing a novel object recognition test, a plus maze test, or a fear conditioning test. The stretch-attend posture, characterized by elongation of the animal’s body, is often considered a response to an object that incites fear or curiosity. Additionally, time spent immobile serves as a measure of fear. The rotation parameter is very useful in research on brain defects. Acceleration can be used to analyze swim burst acceleration in fish.
All external data integrated into your EthoVision XT project can be analyzed in a similar (integrated) manner.
Free interval selection
Free interval selection allows you to define your custom analysis. For example, in a (novel) object test, the main goal is to measure how much interest the animal has with a familiar and/or a novel object. EthoVision XT could already give you the time and frequency of ‘nose point in object zone’, but maybe you are interested in how long it took, over the entire trial, for the animal to show a total of 10 seconds cumulative interest in one or more objects. The new free interval selection makes this very easy to analyze.
Say you want to teach your mouse to jump on top of the shelter to get a reward from the feeder. With free interval selection, you can easily measure how long it took for the animal to move from the top of the shelter to the feeding zone, and compare this number over several trials. The trend of the interval duration can be taken as a measure of learning.
In operant conditioning tasks or radial arm mazes, questions like “How much time did the animal need to get 3 correct lever presses?” or “How long did it take the animal to get to a total of 5 correct arm entries?” are now easily answered using free interval selection. With this method you can also determine how long it took for your animal to learn that it has to stay in the correct arm for, let’s say, 20 seconds consecutively.
In stimulus-response scenarios, you are likely interested in comparing the subjects’ behavior before and after the stimulus was presented. You can select a timeframe before a certain event took place as the starting point of your interval selection. This makes it very easy to see how the behavior of the animal changed in reaction to the stimulus.
Automatic and batch analysis
In addition to batch acquisition, you can also perform automatic analysis and batch analysis. First, select which parts of your data need to be analyzed. Then select the independent variables you are interested in. Now EthoVision XT will automatically analyze your data according to these settings right after the trial has ended or, in the case of batch analysis, after the selected trials have been acquired.
Read more about how EthoVision XT makes your research more efficient.
“EthoVision XT has saved us a lot of time analysing behavioural data - allowing us to do more, faster”
Dr. A. Brigham | Rentokil Initial
In addition to integrated visualization, a heatmap gives you an intuitive and unique view of your data. You can export these at high resolution (including a minimum-maximum scale) for use in presentations and publications.
With EthoVision XT you can easily compare the results between treatment groups, for example by using graphs. You can organize and adjust the designs of these graphs and export them in any standard format (PNG, JPG, BMP, GIF).
Results are also presented in tables, of which you can adjust the layout. This is ideal if your statistical program requires a certain set-up of the data, you can organize and export your table accordingly.
Analysis of hardware events
If you are using EthoVision XT to control external equipment, you can also analyze these hardware events within the software. Read more.