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

American this can lead to difficulties in conducting experiments with groups of
participants who may not be aware of these cultural references.
The differentiation of memory for central and peripheral elements of a
stimulus can provide great insights into memory processes but these type of
experiments are very difficult with the IAPS stimuli. Many negative
photographs may contain several objects or people in the context of a complex
scene, for example a scene of destruction and civil war, whereas positive and
neutral photographs may be more likely to contain just one item e.g. a close up
image of one person’s face or a single object such as a rolling pin on the plain
background of a table. These differences can have important implications for
the objective definition of central and peripheral elements in a picture.
For many of the reasons described above I decided to explore the use of
a different type of stimuli to elicit emotions. In creating my own set of stimuli
similar to those described by Kensinger et al. (2006) it was possible to
minimise many of the problems described above. Namely, the stimuli excluded
any people or faces and each stimulus contained a background and single
object. By creating negative, neutral and positive versions of each scene with
the same neutral background the difficulties with IAPS pictures of different
backgrounds in photographs of different emotional valence were avoided.
There were some difficulties in creating the stimulus set of 72 scenes with a
negative, neutral and positive version of each. One of these difficulties was in
finding 72 plain backgrounds which could be uniquely described and provided
semantically congruent backgrounds for the negative, neutral and positive
objects pairs which had been used in the previous experiment. The constraints
in selection of objects, with the exclusion of faces and people unfortunately
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