@phdthesis{Seelig2021,
  author    = {Seelig, Stefan},
  title     = {Parafoveal processing of lexical information during reading},
  doi       = {10.25932/publishup-50874},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-508743},
  school      = {Universit{\"a}t Potsdam},
  pages     = {xi, 113},
  year      = {2021},
  abstract  = {During sentence reading the eyes quickly jump from word to word to sample visual information with the high acuity of the fovea. Lexical properties of the currently fixated word are known to affect the duration of the fixation, reflecting an interaction of word processing with oculomotor planning. While low level properties of words in the parafovea can likewise affect the current fixation duration, results concerning the influence of lexical properties have been ambiguous (Drieghe, Rayner, \& Pollatsek, 2008; Kliegl, Nuthmann, \& Engbert, 2006). Experimental investigations of such lexical parafoveal-on-foveal effects using the boundary paradigm have instead shown, that lexical properties of parafoveal previews affect fixation durations on the upcoming target words (Risse \& Kliegl, 2014). However, the results were potentially confounded with effects of preview validity. The notion of parafoveal processing of lexical information challenges extant models of eye movements during reading. Models containing serial word processing assumptions have trouble explaining such effects, as they usually couple successful word processing to saccade planning, resulting in skipping of the parafoveal word. Although models with parallel word processing are less restricted, in the SWIFT model (Engbert, Longtin, \& Kliegl, 2002) only processing of the foveal word can directly influence the saccade latency. Here we combine the results of a boundary experiment (Chapter 2) with a predictive modeling approach using the SWIFT model, where we explore mechanisms of parafoveal inhibition in a simulation study (Chapter 4). We construct a likelihood function for the SWIFT model (Chapter 3) and utilize the experimental data in a Bayesian approach to parameter estimation (Chapter 3 \& 4). The experimental results show a substantial effect of parafoveal preview frequency on fixation durations on the target word, which can be clearly distinguished from the effect of preview validity. Using the eye movement data from the participants, we demonstrate the feasibility of the Bayesian approach even for a small set of estimated parameters, by comparing summary statistics of experimental and simulated data. Finally, we can show that the SWIFT model can account for the lexical preview effects, when a mechanism for parafoveal inhibition is added. The effects of preview validity were modeled best, when processing dependent saccade cancellation was added for invalid trials. In the simulation study only the control condition of the experiment was used for parameter estimation, allowing for cross validation. Simultaneously the number of free parameters was increased. High correlations of summary statistics demonstrate the capabilities of the parameter estimation approach. Taken together, the results advocate for a better integration of experimental data into computational modeling via parameter estimation.},
  language  = {en}
}
@phdthesis{Risse2011,
  author    = {Risse, Sarah},
  title     = {Processing in the perceptual span : investigations with the n+2-boundary paradigm},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-60414},
  school      = {Universit{\"a}t Potsdam},
  year      = {2011},
  abstract  = {Cognitive psychology is traditionally interested in the interaction of perception, cognition, and behavioral control. Investigating eye movements in reading constitutes a field of research in which the processes and interactions of these subsystems can be studied in a well-defined environment. Thereby, the following questions are pursued: How much information is visually perceived during a fixation, how is processing achieved and temporally coordinated from visual letter encoding to final sentence comprehension, and how do such processes reflect on behavior such as the control of the eyes' movements during reading. Various theoretical models have been proposed to account for the specific eye-movement behavior in reading (for a review see Reichle, Rayner, \& Pollatsek, 2003). Some models are based on the idea of shifting attention serially from one word to the next within the sentence whereas others propose distributed attention allocating processing resources to more than one word at a time. As attention is assumed to drive word recognition processes one major difference between these models is that word processing must either occur in strict serial order, or that word processing is achieved in parallel. In spite of this crucial difference in the time course of word processing, both model classes perform well on explaining many of the benchmark effects in reading. In fact, there seems to be not much empirical evidence that challenges the models to a point at which their basic assumptions could be falsified. One issue often perceived as being decisive in the debate on serial and parallel word processing is how not-yet-fixated words to the right of fixation affect eye movements. Specifically, evidence is discussed as to what spatial extent such parafoveal words are previewed and how this influences current and subsequent word processing. Four experiments investigated parafoveal processing close to the spatial limits of the perceptual span. The present work aims to go beyond mere existence proofs of previewing words at such spatial distances. Introducing a manipulation that dissociates the sources of long-range preview effects, benefits and costs of parafoveal processing can be investigated in a single analysis and the differing impact is tracked across a three-word target region. In addition, the same manipulation evaluates the role of oculomotor error as the cause of non-local distributed effects. In this respect, the results contribute to a better understanding of the time course of word processing inside the perceptual span and attention allocation during reading.},
  language  = {en}
}
@phdthesis{Hohenstein2013,
  author    = {Hohenstein, Sven},
  title     = {Eye movements and processing of semantic information in the parafovea during reading},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70363},
  school      = {Universit{\"a}t Potsdam},
  year      = {2013},
  abstract  = {When we read a text, we obtain information at different levels of representation from abstract symbols. A reader's ultimate aim is the extraction of the meaning of the words and the text. The reserach of eye movements in reading covers a broad range of psychological systems, ranging from low-level perceptual and motor processes to high-level cognition. Reading of skilled readers proceeds highly automatic, but is a complex phenomenon of interacting subprocesses at the same time. The study of eye movements during reading offers the possibility to investigate cognition via behavioral measures during the excercise of an everyday task. The process of reading is not limited to the directly fixated (or foveal) word but also extends to surrounding (or parafoveal) words, particularly the word to the right of the gaze position. This process may be unconscious, but parafoveal information is necessary for efficient reading. There is an ongoing debate on whether processing of the upcoming word encompasses word meaning (or semantics) or only superficial features. To increase the knowledge about how the meaning of one word helps processing another word, seven experiments were conducted. In these studies, words were exachanged during reading. The degree of relatedness between the word to the right of the currently fixated one and the word subsequently fixated was experimentally manipulated. Furthermore, the time course of the parafoveal extraction of meaning was investigated with two different approaches, an experimental one and a statistical one. As a major finding, fixation times were consistently lower if a semantically related word was presented compared to the presence of an unrelated word. Introducing an experimental technique that allows controlling the duration for which words are available, the time course of processing and integrating meaning was evaluated. Results indicated both facilitation and inhibition due to relatedness between the meanings of words. In a more natural reading situation, the effectiveness of the processing of parafoveal words was sometimes time-dependent and substantially increased with shorter distances between the gaze position and the word. Findings are discussed with respect to theories of eye-movement control. In summary, the results are more compatible with models of distributed word processing. The discussions moreover extend to language differences and technical issues of reading research.},
  language  = {en}
}