This
week I mostly worked on testing the rats in the NICHES study on the attention
task. There are four cohorts of rats in total for this study, but the first
cohort has finished the attention task. I am currently running cohorts 2, 3,
and 4 through this task.
Although
it sounds simple, the attention task contains many steps. It is an experiment
that tests not only the animal’s ability to pay attention, but also how well it
can remember its previous sessions. To start, the rat is trained in the box
through a few programs. There are two levers, one left and one right. Depending
on which box the rat is in, there is a signal light above the right or left
lever. There are multiple stages to this attention task which include:
training, A Shape, 50 signal light, 50 blank lever, 50 signal light and 50
blank lever, 100 trials, and 240 trials. I will be taking you through the
process of each session below. This is experiment is one that takes the longest
because the rat has to pass each program, and if it cannot move on to the next
program until it passes. Naturally, this means that some rats are ahead of the
others, because just like humans some of them are able to understand the
program more easily and quickly.
For
the sake of this explanation, I am going to say the signal light is on the left
(this also corresponds with the pictures). In the box, the light will go off
and if the rat presses the left lever it receives a sugar pellet. Now the rat
does not automatically understand this, so the rat goes through training
sessions and has to pass them in order to move on. Once it understands that the
light means to press the left lever (50 signal light program), it will move on
to the program with 50 blank levers, which means that the light will not go off
and if it presses the right lever it receives a sugar pellet. Once that program
is passed, it goes through the program where it has 50 signals and 50 blanks.
Once it completes that program, however, the sessions get more intense.
The
next phase that the rat will go through in this attention task is a program we
like to refer to as "V." This program is a set of 100 trials with
both signals and blanks. Thus, during this if the signal goes off the rat
should press the left lever to get a pellet and if it is blank (no light) the
rat should press the right lever to get a pellet. However, unlike the previous
program this is random so the rat has to pay attention to when the light goes
on and when it stays off. This program is slightly more intense because once it
passes the regular "V" session we move the signal light farther up to
the "V+1" position. The rat then goes through 100 trials, and has to
pass. A passing score is a score greater than or equal to 70%. The signal light
then gets moved up one more spot, and the rat again has to pass 100 trials in
the "V+2" session. The third and final phase of this "V"
program is moving the light into the center of the box. Again, the rat has to
pass 100 trials in this program we refer to as "V+C." Once that is
passed, the rat is almost done with the attention task as it has one more phase
to go through.
The
last and final phase of the program is what we refer to as "V7." The
signal light is in the center of the box, like the "V+C" position,
but the rat has to pass 240 trials this time. Now, unlike the other programs,
the rat has to pass the “V7” program six times. Once it has passed six times,
the rat has successfully completed the attention task.
While
the program itself can take time, we also have to always make sure the boxes
are working correctly. Sometimes the sugar pellets will get stuck to the metal
plates they come down from, so we have to make sure those are clean. We also
regularly clean out the bottom of the cages. Although the attention task was a
little daunting at first, I have come to really enjoy it. I started working on
this in the middle of cohort 2 and 3 completing the task, and when cohort 4 was
just going through the training sessions. It is really enjoyable and fun to see
which rats move through the programs quickly and it is fun to see which rats
pass! Overall, this week was pretty enjoyable because I was also able to run
some of the NICHES rats through figure 8 training. I am really starting to have
fun with the work I am doing as I am getting more involved with the
experiments.
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| Attention task box |
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| Attention task box with signal light at V+C and V7 position |
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