OK, we'll give you some supplemental
information about the Sniffy Study that isn't available on other links
that will help you with your paper. We'll also tell you exactly
what statistics to run.
You were observing virtual rats in an operant chamber immediately after
a
period
during which the rats received a series of unsignaled high
insensitivity
shocks (Condition A - details below) or received a series of trials in
which
there was no signal and no shock (Condition B) - that is, the virtual
rats just
hung-out
in the chamber. Based upon reading the paper you compressed, you
must
have deduced that we expect there to be more freezing in the post-shock
observation
period than after the period without shock. That is, this should
happen
if virtual rats behave in the same way that published literature
indicates live rats do.
You know how many observations you made and what the
inter-observation-interval
was, so we don't need to do that again here. You should tell the
reader
what behaviors you observed, but also tell the reader that you will
only
be reporting on Freezing. All other behaviors will be considered
non-Freezing.
For inter-rater reliability, we calculated what we've been calling the
percentage
of possible agreements for Freezing observations. That is, if
either
observer reported Freezing we counted that and divided this number into
the
number of times the observers agreed on Freezing (then multiplied by
100, of
course).
We only looked at the Freezing ratings in the post-shock
condition.
Only the post-shock condition was examined because Freezing virtually
never
happens in an unstressed animal and you can't get percent agreement
when
there's nothing to agree upon. Dr. Baril has discussed
inter-rater reliability
in class and what level of agreement you need to say that things are
pretty
OK. No observer pair had Percent Possible Agreement values of
less
than 81% (Range 81-98%). You'll see these data in the
output
you'll get from the supplemental syntax provided below.
The main analysis here was a
t-test comparing the average
(across
the two observers) percentage of Freezing observed post-shock versus
post-control.
The reason we averaged the number should be pretty obvious. We
also,
independently for the shock/no shock conditions, used
t-tests
to
compare
freezing levels in the first 30 trials versus the 2nd 30 trials.
Why?
We were looking for evidence that freezing/fear decreased as time since
the
last shock passed. Of course, we didn't expect a change in
behavior
for the no shock animals, since there was no change in their
environment. There was a big change in the shock condition
animals - they now were getting
no shocks. You'll see that the latter two
t-tests were
not significant.
When discussing this lack of significance, you might suggest that 10
minutes
was not enough time for fear to dissipate substantially - just a
thought,
it's your paper. I sure don't want to see my words showing up in
your
paper. I do want to see my mentoring/guidance show up there,
however.
Ok...that's the big picture.
Below, you'll find some details we haven't told you yet that may
prove
useful for your paper :
- Monitor Size = 28.5 cm x 21.4 cm
- Sniffy Chamber Size (on this particular monitor) = 13.3 cm x 8.5
cm<>
- Sniffy A
- fear conditioned with no cue (except for being in the
chamber itself)
- "High Shock"
- Trial presented 40 times
- Interval between trials = 5 minutes
- Sniffy B
- Stimulus free trials - no shock, no cues
- Trials presented 40 times
- Interval between trials = 5 minutes
- Sniffy Program Details
- Sniffy the Virtual Rat, Pro Version 2.0
- Build Version: 6.1f1
- Publisher: Thomson
Wadsworth
Good luck!! (
Supplemental syntax)
.