Naslov
Violation of expectations in sequence processing

Autori
Bubić, Andreja

Vrsta, podvrsta i kategorija rada
Ocjenski radovi, doktorska disertacija

Fakultet
Faculty for Biological Sciences, Pharmacy and Psychology

Mjesto
Leipzig, Germany

Datum
01.10

Godina
2009

Stranica
143

Mentor
Schroeger, Erich

Neposredni voditelj
Schubotz, Ricarda I.

Ključne riječi
attention; deviant detection; EEG; fMRI; frontal cortex; prediction; sequence processing

Sažetak
The goal of the present thesis was to explore the process of detecting sequential deviants within the context of predictive perceptual processing as explored using sequences of visual stimuli. These events violate expectations formulated within such perceptual sequences whose structure is defined by the order of stimulus presentation. In the first two experiments, the detection of such sequential deviants was compared to the detection of feature deviants which violate the expectations formulated based on perceptual features of individual stimuli. The results from both experiments indicated a dissociation between the processing of these two types of deviants. This was shown both on the level of temporal dynamics using electroencephalograpy (EEG), as well as the brain areas engaged in processing feature and sequential deviants using functional magnetic resonance imaging (fMRI). Following this, the processing of sequential deviants was additionally investigated using fMRI within perceptual sequences defined by different stimulus features and on differing levels of specificity. Comparison of results obtained across all three fMRI experiments indicates a partly overlapping, but not uniform pattern of activations supporting the detection of sequential deviants. Such findings suggests that specific factors defining the sequential structure strongly influence which brain regions become engaged in processing violations introduced in such sequences. The most important of these factors includes the stimulus property defining the sequence and the characteristics of sensorimotor transformations it affords. In addition, the specificity of expectations which can be formulated within the sequence also influences the engagement of brain regions in detecting sequential deviants. Finally, although not explicitly explored, the influence of other sequence properties, e.g., number of sequence repetitions within the trial, might also modulate the involvement of the identified brain networks in detecting such events. In conclusion, detection of sequential deviants does not represent a uniform process, but is highly dependent on the properties of regular sequences which determine the nature of expectations being formulated and consequently violated by the presentation of such events.

Izvorni jezik
Engleski

Znanstvena područja
Psihologija

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