Mood Dependence 79that parallels the results obtained from normal subjects
whose moods have been modified experimentally (see Eich
et al., 1994).
The most surprising results stemmed from the test of
inkblot recognition. As reflected by the dark bars in Fig-
ure 3.4, the patients were better at discriminating old inkblots
from perceptually similar lures when tested under matched as
opposed to mismatched mood conditions (mean correct
recognition=48% vs. 34%). Moreover, confidence ratings
(made on a 5-point scale) were higher for correct than for in-
correct recognition decisions (means=1.9 vs. 1.1) in every
encoding or retrieval condition. This implies that the test
tapped explicit, recollective processes and that the patients
did not respond to the recognition alternatives solely on the
basis of an implicit feeling of familiarity. In short, the pa-
tients showed an effect—mood-dependent recognition—that
is seldom seen in normals, perhaps because the former sub-
jects experience stronger, more intense moods than do the lat-
ter. Alternatively, it may be that the key to demonstrating
mood-dependent recognition is to use novel, complex, and
highly abstract stimuli (e.g., Rorschach-like inkblots) that are
apt to be perceived and encoded in an emotionally biased
manner. What role—if any—such stimulus properties play in
the occurrence of mood-dependent recognition remains to be
seen, ideally through a combination of clinically relevant and
laboratory-based research.
Closing Comments
In a cogent review of research on implicit memory, Schacter
(1992) made a case for taking a cognitive neuroscience
approach to the study of unconscious, nonintentional forms of
retention. The crux of the approach is to “combine cognitive
research and theory, on the one hand, with neuropsychologi-
cal and neurobiological observations about brain systems, on
the other, making use of data from brain-damaged patients,
neuroimaging techniques, and even lesion and single-cell
recording studies of nonhuman animals” (Schacter, 1992,
p. 559).
To illustrate the value of this hybrid approach, Schacter
identified several instances in which data derived from am-
nesic, alexic, or other neurologically impaired individuals
provided a test bed for theories that originated in research in-
volving the proverbial college sophomore. He also showed
how studies of normal subjects could constrain neurologi-
cally inspired ideas about dissociable memory systems,
such as the perceptual representation system posited by
Tulving and Schacter (1990). More generally, Schacter
argued that by adopting a cognitive neuroscience approach
to implicit memory, one is encouraged to draw on data and
ideas from diverse areas of investigation, which in turn
encourages greater reliance on the logic of converging oper-
ations (Roediger, 1980, 1990).
We suggest that similar advantages would accrue through
the interdisciplinary study of MDM and that mood depen-
dence, like implicit memory, is most profitably explored
through experimentation that cuts across traditional research
domains. With respect to MDM, the relevant domains are
cognitive, clinical, and social/personality psychology, and,
even at this early stage of research, there are already several
reasons to recommend their interplay.
For instance, the positive MDM results obtained in the lab-
oratory using autobiographical-event generation and recall
provided the rationale for giving the same tasks to patients with
bipolar illness. By the same token, the observation that shifts
between (hypo)manic and depressed states impair the recogni-
tion of nebulous, Rorschach-like patterns casts new doubt on
whether mood-dependent memory is a cue-dependent phe-
nomenon, as many cognitively oriented theorists have long
maintained (e.g., Bower, 1981; Eich, 1980). Moreover, an
intensive investigation of a patient with multiple personality
disorder (Nissen et al., 1988) has led not only to a clearer un-
derstanding of the connection between interpersonality amne-
sia and MDM, but also to the intriguing prediction that both
mood-congruent and mood-dependent effects in normals
should be particularly potent for semantically rich materials
that can be interpreted in different ways by different people in
different moods. Whether or not this prediction pans out, it
nicely illustrates the novel ideas that are apt to emerge when
the problem of mood dependence is pursued from both a cog-
nitive and a clinical point of view.
Recent discoveries in social/personality psychology also
suggest a number of promising directions for future MDM re-
search. For example, the concept of affect infusion, which de-
veloped out of social cognitive studies of mood congruence,
has clear yet counterintuitive implications for mood depen-
dence (e.g., that a shift in affective state should have a greater
adverse impact on memory for fictional characters who seem
odd rather than ordinary). Testing these implications will re-
quire MDM researchers to construct materials and tasks that
are considerably more socially complex and personally en-
gaging than anything used in the past.
A different set of implications arises from recent investi-
gations of individual differences in mood congruence. The
results of these studies suggest that that mood-congruent ef-
fects are small, even nonexistent, in people who score high
on standardized measures of Machiavellianism, self-esteem,
need for approval, and Type-A personality. As Bower and
Forgas (2000, p. 141) have commented, high scores on these
scales “probably indicate a habitual tendency to approach
certain cognitive tasks from a motivated perspective, which
should reduce affect infusion effects.” Assuming, as we do,