Marsh,
R.L., Hicks, J.L., & Cook, G.I. (2005). On the relationship between effort toward an ongoing task and cue
detection in event-based prospective memory. Journal
of Experimental Psychology: Learning, Memory, and Cognition, 31, 68-75.
Introduction
Event-based
prospective memories are memories for tasks to be performed in the future in
response to a specific cue. Laboratory
studies of this type of memory require subjects to form intentions to make a
special response in addition to or in place of responding to an ongoing task. The relative importance of the prospective
memory response or the ongoing task can be varied, and thus attention is
believed to be shifted from one part of the task to the other. Previous studies have shown that when more
importance is placed on the ongoing task, performance on the prospective task
decreases. When the weighting is
reversed, performance increases on the prospective task. The authors believed that this weighting
would naturally vary on any prolonged task, as it would in a natural setting,
and developed their experimental design accordingly. Their predictions were that prospective
memory performance would be worse when subjects’ efforts were more devoted on
the ongoing task than when it was less devoted.
A further issue laboratory-based prospective memory
studies is task-appropriate processing as developed by Maylor
(1996, 1998). In this view, intention
cues are more easily detected when they are processed in the same manner as the
ongoing task, e.g. processing semantic cues (animal words) during a semantic
task (words vs. non-words). Attention
was assumed to be divided between identifying the cues and performing the
ongoing task when task-appropriate processing was involved. However, when performing the ongoing task
requires a type of processing that is not helpful in identifying the cue,
attention is not divided believed to be divided by performing both tasks. The authors predicted that a detriment to cue
detection due to attentional resources being devoted to the ongoing task in
high effort conditions would only be noted in task-appropriate situations.
The authors intended to address the implications of
their results for the multiprocess theory of McDaniel et al. (2004) and Smith’s
(2003) preparatory attention and memory (PAM) theory.
Experiment 1
Methods: 92
Results: In
all three conditions, subjects increased their response rates from the Low- to
Medium- to High-effort trials.
Significant task interference was noted as latencies were longer for
both intention conditions compared to the No-intention condition. This interference was greater for the
Palindrome group than the Animal group. Accuracy
did not differ as a function of effort nor as a
function of group. On Low-effort trials,
prospective memory performance was significantly better for the Animal
intention group than the Palindrome intention group. On High-effort trials, however, there was not
a significant difference. Further, there
was no significant difference between Low- and High-effort trials in the
Palindrome group.
These
results support the argument that when cues are processed in a manner
differently than that used for the ongoing task (task-inappropriate
processing), as in the case of the Palindrome group, then devoting more or less
attention to the ongoing task will not affect prospective memory performance. The results of the Animal group, however,
show the detriment to prospective memory performance that occurs in
task-appropriate processing when attention is redirected towards the ongoing
task. The attentional source is shared
between the ongoing and prospective tasks in the latter type of processing, and
when attention is shifted towards the ongoing task in the High-effort condition
it is taken away from cue detection and decreases prospective memory
performance. A concern raised by these
results, however, was the very low prospective memory performance rates in the
Palindrome condition which was the impetus for Experiment 3.
Experiment 2
Methods: 93
Results:
Significant task interference was obtained with both intention groups having
slower latencies than the No-intention group, though these two groups did not
differ from one another. Increased
effort led to an increased speed of responding.
Accuracy was shown to be a function of neither effort nor group,
indicative of the absence of a speed-accuracy tradeoff. The Palindrome intention group performed
significantly better on Low-effort trials than the Animal intention group, but
on High-effort trials these two groups did not differ. The Animal intention group did not perform
differently in the Low- or High-effort conditions. In Experiment 2, the ongoing task required
orthographic processing as did the detection of Palindrome cues. Hence, this group was affected by the
redirection of attention that results by varying effort. Animal cues required semantic processing
which is an example of task-inappropriate processing, and thus this group is
spared the detrimental effect caused by the Effort manipulation. Combining the results of Experiments 1 and 2
shows a pattern of results consistent with the predictions of the authors where
attention usurped by the ongoing task only has an effect on prospective memory
performance when task-appropriate processing is engaged.
Experiment 3
Methods: 69
Results: Reaction
time significantly decreased with increased effort, and overall reaction times
were similar to those obtained in Experiment 1.
Unlike Experiment 1, however, increased effort did significantly
decrease accuracy even though it remained at very high levels overall. Overall detection of palindromes was 9%
higher than in Experiment 1. As in
Experiment 1, the Animal intention group performed better on the Low-effort
trials than the High-effort trials while the Palindrome intention group
performance did not differ between the trial types.
Conclusion
The authors were successful in demonstrating that
increasing the allocation of attention to the ongoing task led to decrease in
prospective memory performance only when task-appropriate processing was
involved. In McDaniel et al.’s multiprocess view, task-appropriate processing supposedly
led to automatic cue detection but the evidence provided in this study
challenges this view, and the authors suggest a revision to this view and
follow-up experiments. Smith’s PAM model
is also challenged, with the suggestion that multiple attentional
mechanisms should be considered and that decreased decision latencies are not
necessarily predictive of increased prospective memory performance. Metacognitive
strategies for attention allocation at the outset of a task are considered
essential for the performance and understanding of an event-based prospective
memory task, and the subsequent shift in attention allocation over the course
of task completion is considered the essential cause of varying performance.
Important Legal
Disclaimer: The preceding are articles we read together in the Lampinen Lab Fall 2005 false memory reading group. By
clicking on the button next to the article you can see the summary of that
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is of course the case that the views expressed in the summary do not
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the University of Arkansas, the Razorback Football or Basketball teams
(although we're not sure about cross country), people living down the street
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matter except for the student who wrote the summary (and they don't necessarily
believe what they wrote either).