tesis doctoral - e-Spacio - Uned

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Apéndice II
condition, two sloping lines inducing the Ponzo illusion. The task of the participants consisted in
estimating the length of the black lines when the dots were grouped or ungrouped. At the end of
the experiment, an inattention condition (similar to that of Mack et al., 1992) was presented,
and the participants were asked to report about the grouped pattern. The results showed that
the participants were unable to report the pattern. However, when the dots were grouped
forming the Müller-Lyer or Ponzo illusions, their performance revealed that the estimation of the
lines´ length was influenced by both illusions. The authors suggested that grouped patterns
were perceived without attention but not encoded in memory (i.e. innatentional amnesia, see
Wolfe, 1999 for a review). Later studies reported similar results (Chan & Chua, 2003; Kimchi &
Razpurker-Apfeld, 2004; Lamy, Segal & Ruderman, 2006; Russell & Driver, 2005).
1.2. Innattentive processing is not necessarily identical to
preattentive processing
The above studies have shown that grouping can occur and affect task performance
under conditions of inattention. Undoubtedly, these works have been an important contribution
to the knowledge about the limits of human visual system to process grouped patterns.
However, these studies do not permit to determine whether the innattentive processing of
grouped patterns can influence the subsequent attentional processing of the same patterns.
From our point of view, it is not possible to use an inattention paradigm to test preattentive
hypothesis of visual processsing. A preattention paradigm is necessary for testing preattentive
hypothesis. Our proposal is based on the idea that inattentive processing is not necessarily
identical to preattentive processing. Consequently, an inattention paradigm is inadecuate to
study preattentive processing. An inattentive process is (just) a visual operation carried out
while attention is involved in a different visual task. The inattention paradigm developed to study
these process only can provide data about a visual processing without attention that happens
concurrently with an attentional processing of another stimulus at a different position.
In contrast, we propose that a preattentive process is a visual operation applied to a
specific stimulus in absence of attention that influences subsequent attentional processing of