PDF (PhD Thesis Susan Chipchase) - Nottingham eTheses ...

Section 3.1. Introduction
Section 3. Experiment 10:
In experiment 9 it was found that when stimuli were blocked according
to the emotion of the object in a scene there was emotional visual specificity of
memory but no evidence of attentional narrowing onto the object in negative
scenes. There was a confounding variable in experiment 9 that participants
were warned in advance of the emotion of the objects that would be presented
in the next block in addition to the change from mixed to blocked lists of
stimuli. Experiment 10 was conducted to untangle this confounding variable by
presenting stimuli in the same pseudorandomised lists as experiment 6 and 7,
but providing participants with a warning of the emotion that would be present
in the object of the next scene.
Blocking lists of stimuli into separate emotional groups may have two
effects; emotional stimuli may no longer be distinct from other stimuli around
them (i.e. not distinctive relative to the surrounding stimuli) and they may also
no longer be unexpected. In pseudorandomised lists participants cannot know
whether a negative, neutral or positive stimulus will be displayed next and
emotional stimuli may create different effects when they are experienced
unexpectedly than neutral stimuli. As discussed in the chapter introduction,
different neural networks are activated for unpleasant events that are expected
(Herwig et al, 2007) which implies the possibility of correspondingly different
processes activated for unpleasant events that are unexpected.
However, in Experiment 9 we found that the emotional enhancement of
memory was not eradicated by blocking the stimuli into emotional groups. The
aim of this experiment is to further investigate the factors that influence the
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