ACTOGRAMS

=Actograms= Actograms are a simple type of graph that show activity over a given period of time. If you look at the actograms below, the dark bands represent periods of activity. [image:http://i.imgur.com/1p0mCTc.png?1] If we look at the first graph we can see a repeated pattern of activity, whereas in the second graph the activity is sporadic / shows no pattern. The first displays a biological rhythm, while the second does not. If the environmental cues were removed and the biological rhythm was under the control of an endogenous biological clock, we would expect the pattern of activity to continue roughly unchanged. You will notice that along the bottom (x axis) there are actually two 24 hour periods. Two days were put back to back. This is often done to make it a little easier to see the repeating period of activity. If we look at the actogram on the left, we can clearly see here that the activity repeats each day, this is a circadian rhythm. We can see here that this organism is active between roughly 18:00 hrs (6pm) and 6:00 hrs (6am). Therefore we could further describe the activity of this organism as nocturnal. For the above graph we can make the following conclusions: *'''Period of Rhythm''': approx 24hrs = Circadian (repeats each day) *'''Period of Activity''': approx 12hrs (6pm - 6am) *'''Type of Activity''': circadian, nocturnal