Biomedical Engineering Reference
In-Depth Information
tests and/or
2
tests to compare between groups the summed CS responses or the CS
responses in the last acquisition trial. Obviously, one may want to focus just on the
last acquisition trial and in this case, use of these tests is appropriate. However, if
entire acquisition curves are to be compared between groups, other solutions have
to be found. Cochran
Q
test cannot be used to this end as it is a within-group test.
Thus, repeated-measures analyses applicable for between-group comparisons have
to be used. A solution to this problem is the use of standard two-factor analysis of
variance (ANOVA) for repeated measurements, with one factor being the treatment
to be analyzed (e.g., paired vs. unpaired CS responses) and the other factor the
response along trials (e.g., trials one to fi ve in the example of Fig.
2.3a,d
). The inter-
action between both factors will also be computed allowing the detection of specifi c
treatment x trial effects. ANOVA procedures are in principle not applicable in the
case of dichotomous data; yet Monte Carlo studies have shown that it is permissible
to use ANOVA on dichotomous data (Lunney
1970
) if comparisons imply equal cell
frequencies and at least 40 degrees of freedom of the error term. By fulfi lling these
conditions, the use of repeated measurement ANOVA will allow not only between-
group comparisons but also within-group analysis as achieved by the Cochran test.
To compare response levels to the CS and the novel odor (NO) in the retention
tests, a McNemar test is typically used as it is applicable for paired-sample testing
of dichotomous data. Note that given the dichotomous nature of responses, one has
to consider not only correct responses (i.e., CS+:1/NO:0) but also the three possible
cases of incorrect responses (i.e., CS+:1/NO:1; CS+:0/NO:0; CS+:0/NO:1).
χ
2.4
Research on Honeybee Learning and Memory
Using Olfactory Classical Conditioning of PER
In this chapter, we have introduced fi ve-trial absolute conditioning with ITI of
10 min. The choice of such a long interval determines a conditioning with “spaced
trials,” in contrast with protocols employing “massed trials” in which trials are
separated by very short (typically 1 min) intervals. Extensive study of associative
olfactory conditioning of PER revealed the existence of different memories,
depending on US intensity (i.e., the amount and/or quality of sucrose solution
received during conditioning), the number of conditioning trials, and the ITI
(Menzel
1999
,
2001
; Menzel et al.
2001
). The memory induced by a single condi-
tioning trial decays rather quickly, mostly after 1 day (Menzel
1990
; Hammer and
Menzel
1995
) and is sensitive to amnestic treatments (Menzel et al.
1974
; Erber
et al.
1980
). This memory can be dissected into two memory phases, short-term
memory (STM) and medium-term memory (MTM). These phases are independent
of protein synthesis (Grünbaum and Müller
1998
). In contrast, multiple condition-
ing trials induce a stable, long-lasting memory, which can be retrieved several days
after conditioning (Menzel et al.
2001
). Trial spacing is a dominant factor for both
acquisition and retention. Generally, massed trials lead to impaired memory
