Taylor,
R.S., Marsh, R.L., Hicks, J.L. & Hancock, T.W. (2004). The influence of partial-match cues on
even-based prospective memory. Memory, 12,
203-213.
The
main purpose of this study was to investigate the effects of partial-match cues
on the success rate of a prospective memory task. A partial-match clue is defined as a cue that matches the
prospective cue on some dimension. The
prospective cues in this series of experiments are animals that begin with the
letter “L”. In this case, the semantic
partial-match cues were animal names that started with letters other than “L,”
and orthographic partial-match cues were non-animal words that started with the
letter “L”.
Taylor
and colleagues present four logical possibilities than may occur if these
partial-match cues are presented. The
first is that nothing will happen to the success rates of prospective
memory. The partial-match cues may not
trigger intention retrieval, and, thus, cause no increase or decrease in the
success rate. A second possibility is
that the partial-match cues act outside of the conscious, but still cause an
increase in the PM success rate. The
third proposal is that the partial-match cues will consciously activate the
prospective intention, increasing PM success.
The fourth and final possibility is that the partial-match cues may have
some sort of aversive effect on the PM success rate.
Experiment
1
The
first experiment was conducted in order to manipulate the type of partial-match
cue (semantic vs. orthographic) to test if there were differences in these two
type of partial-match cues.
Results
The
group receiving partial-match cues showed a significantly higher PM hit rate
than did a control condition. Taken
individually, the group receiving the orthographic partial matches showed a
significantly higher PM hit rate than the control group, while the semantic
group showed the same effect with marginal significance.
A
second interesting finding lies in the measure of response latencies to the
partial-match cues in the ongoing pleasantness task. The processing latencies were not statistically different to the
orthographic cues and the remaining non-PM cues. However, he processing
latencies were statistically different to the semantic cues and the remaining
non-PM cues.
Experiment
2
The
second experiment was designed to investigate any differences that may occur
due to a difference in the number of partial-match cues presented. It is possible that the presence of any
partial-match cues creates a ceiling effect, i.e. increasing the number of
partial-match cues does not increase the PM hit rate. In addition, the experimenters chose to test for any spacing
effects that may be present by placing the partial-match cues evenly or
randomly throughout the presented words.
This last manipulation was included to foster cross-experiment
comparison, as well.
Results
There
appeared to be no significant effect of spacing on the PM hit rate, nor was
there an interaction with the number of partial-match cues. There was a significant effect of number on
the PM hit rate. Examination of the
means shows that the increase from the control group to the four partial-match
cue group is almost twice as large as the increase from four to eight
partial-match cues. There is no
significant difference between the four and eight partial-match cue groups when
pooled over spacing.
Latencies
in this experiment were longer on the partial-match cue trials, as in the last
experiment. It should be noted that
only semantic cues were used in this experiment.
Experiment
3
Moving
in a slightly different direction, experiment three tested effects of external
reminders of the prospective task given during the ongoing task. The experimenter wished to examine the
possibility that increasing the number of these reminders might increase the PM
hit rate. No partial-match cues were
used in this experiment.
Results
The
external reminder did significantly improve PM hit rates, but increasing the
number of the reminders did not create an additional effect. This is analogous to the effect found in the
previous experiment with the semantic partial-match cues.
General
Discussion
Since increasing the number of partial-match
cues presented resulted in a numerical increase in performance (not
statistical), it stands to reason that the increase in number of partial match
cues results in an increased probability of noticing the cues and retrieving
the PM intention. If this is true, then
partial-match cues cause self –initiated retrieval, unlike the external
reminders given in experiment three.
Therefore, with external reminders the information is reprocessed, while
with partial-match cues the intentions are retrieved and reprocessed.
Since
research to date has often used PM paradigms with simple retrospective
components, the effect of partial-match cues is most likely on the PM
component.
These
partial-match cues may be increasing the associative strength between the PM
cue and intention. This would
automatize the process much in the way spoken about by McDaniel and Einstein
(2000). Results from the first two
experiments support this idea. However,
the results do also support the idea of increased retrieval sensitivity.
There
is one piece of information speaking against the retrieval sensitivity
aspect. That piece of data is the lack
of increased latencies on the orthographic cues in experiment one. If there is some type of practice effect, it
should show in these latencies as well.
Final
note about the current data: there may be more than one explanation for the PM
hit rate increase caused by these partial-match cues. While the data support the above-mentioned explanations, the data
in experiment one were presented in a context of a more semantic ongoing task. Further experimentation with a orthographic
ongoing task is necessary to solidify the above-mentioned conclusions.