Abstract
OBJECTIVE
Anticipating an upcoming event is important in our daily life and beneficial for
survival. The organism becomes more effectively prepared to secure the
health-positive stimuli and escaping from or avoiding health-negative stimuli. The
preparation enables the organism to improve the performance efficiency. However,
anticipation is not always beneficial to the organism because the stimulus that elicits
anticipatory response may be a false alarm. When anticipation becomes chronically
unfulfilled, emotional, arousal and attention components of anticipation can interfere
with cognitive performance, decision making, and social function, resulting in
impaired daily living (see, for example, Bechara & Damasio, 2005) as manifested in
the symptoms of anxiety disorder. Cheng et al. (2018, OHBM) suggested that
linguistic warning triggered a non-specific anxiety. We wanted to know how linguistic
warning could affect cognitive performance, therefore we extended their study and
examined the effects of anticipation and emotion on memory performance. Prior
research has shown memory is enhanced by emotional stimuli (Nashiro & Mather,
2011). There are two important components of emotion, arousal and valence (i.e.,
positive vs. negative), both could affect memory performance. Brain areas jointly
activated by the anticipation of and exposure to aversive pictures include amygdala,
anterior insula (Nitschke, Sarinopoulos, Mackiewicz, Schaefer, & Davidson, 2006),
which amygdala also involved in emotional memory. Present study investigated
whether anticipatory fear signaling an upcoming aversive event enhanced the
emotional memory.
METHOD
33 healthy participants conducted this two-stage study, including the consistency
evaluating task and the recognition task. In the first stage, participants viewedaversive and neutral pictures, 60 pictures of each valence, preceded by linguistic
statements. Pictures were taken from the International Affective Picture System
database (Lang, Bradley, & Cuthbert, 2005). The statements could be aversive or
neutral. Participants had to decide whether the valence of the picture matched the
previously shown statement. No instruction of memorizing the pictures was
announced. With 20 minutes delay after finishing their consistency-evaluating task,
participants were asked to complete a surprise recognition task, in which they had to
decide whether the pictures had appeared during the consistency-evaluating task.
Pictures of old target and distractor were shown, where the old target refers an image
that was previously presented, and the distractor refers to the image related to old
target but never shown in the previous task. To clarify whether participants actually
remembered the pictures or just knew it, we also arranged the source memory
question in the recognition task. The question was forced-choice task when they
identified the picture as previously presented, then they were asked what the
statement before the picture was (neutral/aversive/forgotten).
RESULTS
The valence of picture didn’t have main effect on memory performance, F(1,128) =
1.654, p = .201. Results revealed that the hit rate of the aversive stimuli was at a
comparable level with that of neural stimuli. However, the high hit rate was
accompanied by relatively high false alarm rate in comparison to the neural stimuli.
After the correction, there isn’t significant difference between the hit rates of aversive
and neural stimuli. We found the statement had main effect on memory performance,
F(1,128) = 26.309, p < .001, indicating the picture followed by aversive statements
have better recognition for than neutral statements. We also found interaction between
valence and statement, F(1,128) = 250.717, p < .001, which recognition memory was
enhanced when the statement matches the valence of the picture. For the source
memory, participants had better recall when the statements of pictures are matched
with the valence of the pictures.
Discussion and Conclusion
These results indicated that participants’ performance was affected by linguistic
warning and the consistency of the statements and the valence of pictures.
The results of valence not having the main effect on memory suggest participants
might have adopted a relatively liberal criterion in judging aversive stimuli. Reason
for the results might be due to the physiological mechanism, neuroscience studies
have shown that aversive stimuli are associated with rapid amplification of the neural
response (Keil, Stolarova, Moratti, & Ray, 2007). Prior studies have shown memory isenhanced by the emotional stimuli, but they might overlook the possibility of different
standards participants adopted between emotional stimuli and neural stimuli.
Results of anticipation having main effect on memory performance support the study
by Mackiewicz, Sarinopoulos, Cleven, & Nitschke (2006), which they also found that
anticipatory fear plays an important role in immediate recognition task. While they
had the results similar to ours, they also point out that the valence of pictures involved
in delayed (two weeks after the anticipation session) recognition task.
The interaction between valence and statement and the results of source memory
indicated the performance was affected by the consistency of valence of pictures and
statements. It might point out the importance of context consistency, which
participants learned much better when the context matches. It might also apply to the
field of education, when the background knowledge of students meets what they’ve
learned or been shown, they might have better memory and learning.
Future study can focus on the effects of positive anticipation and valence of picture,
which could much more suggest the context consistency in the field of education.
Also the delayed recognition task Mackiewicz, et al. (2006) did may also be
considered in the future study, as the main effect on performance might altered.