Reduction and calibration of eye monitor data

The present paper presents FORTRAN programs for reducing eye monitor output to fixations and for mapping these fixations to locations in the stimulus space. Flexible parameters of the fixations program allow for determination of the beginning and end of fixations under different resolution criteria and for indicating loss of accurate measurement. The calibration program is based on a rectangular 9-point fixation grid. Each fixation is rescaled within this grid by solving for a quadratic equation. The rescaled values are output in a flexibly determined rectangular coordinate system that is related to the stimulus space, such as character position on the screen. The programs were developed for the 60-Hz Applied Sciences corneal reflection eye monitor, but they may be used with a number of other systems.     

Size of the Mueller-Lyer illusion as a function of its dimensions: Theory and data

In tests with naive subjects, it was found that: the apparent length of a test shaft (1) increases with angle of wing to shaft to a maximum of about 160° (wings out), and (2) is an inverted-U function of wing length, with maximum when wing length equals shaft length; (3) all effects are approximately proportional to shaft length; and (4) the angle exerts its effect within a small region near the tip of the shaft, the region extending about one-seventh the shaft length. The effects apparently do not result from simple distortion of the retinal image, but some may result from assimilation or confusion in coding image into lengths, and some effects apparently arise as lengths are combined into judgments. The new data are shown to agree in quantitative detail with results collected from 1896 to the present.     

SWIFT: a dynamical model of saccade generation during reading

Mathematical models have become an important tool for understanding the control of eye movements during reading. Main goals of the development of the SWIFT model (R. Engbert, A. Longtin, & R. Kliegl, 2002) were to investigate the possibility of spatially distributed processing and to implement a general mechanism for all types of eye movements observed in reading experiments. The authors present an advanced version of SWIFT that integrates properties of the oculomotor system and effects of word recognition to explain many of the experimental phenomena faced in reading research. They propose new procedures for the estimation of model parameters and for the test of the model's performance. They also present a mathematical analysis of the dynamics of the SWIFT model. Finally, within this framework, they present an analysis of the transition from parallel to serial processing.     

Fixation durations before word skipping in reading

We resolve a controversy about reading fixations before word-skipping saccades which were reported as longer or shorter than control fixations in earlier studies. Our statistics are based on resampling of matched sets of fixations before skipped and nonskipped words, drawn from a database of 121,321 single fixations contributed by 230 readers of the Potsdam sentence corpus. Matched fixations originated from single-fixation forward-reading patterns and were equated for their positions within words. Fixations before skipped words were shorter before short or high-frequency words and longer before long or low-frequency words in comparison with control fixations. Reasons for inconsistencies in past research and implications for computational models are discussed.     

The effects of mellow and frenetic music on reported cognitions resulting from auditory subliminal messages

Building on the work of Henley and Dixon (1974) and Mykel and Daves (1979), we investigated the effects of mellow and frenetic music on reported cognitions resulting from auditory subliminal stimuli. College students (N = 120) were randomly assembled into six groups. One third of the students heard four subliminally transmitted water-related words, one third heard four subliminally transmitted family-related words, and one third heard no subliminal stimuli. Either mellow or frenetic masking music was played for half the students in each group. Students reported more word-related imagery in the mellow music conditions than in the frenetic conditions, although the reported imagery did not correspond with the subliminal messages presented.     

On the devalued self: Implications for a transtheoretical psychotherapy

An outline of a transtheoretical psychotherapy dealing with the participants' individual and interacting self-concepts is presented. It is believed that this approach (1) is consistent with social learning and conflict theories of psychopathology, (2) provides a concise definition of the patient's central problem and of the relevant goals of treatment, (3) suggests ways of understanding the centrally important covert processes of psychotherapy and of dealing with the participants' resistances to treatment, (4) offers empirical criteria for determining treatment progress and for terminating treatment, and (5) suggests possibilities for psychotherapy research based on empirical criteria.     

Working memory in children: tracing age differences and special educational needs to parameters of a formal model

Parameters of a formal working-memory model were estimated for verbal and spatial memory updating of children. The model proposes interference though feature overwriting and through confusion of whole elements as the primary cause of working-memory capacity limits. We tested 2 age groups each containing 1 group of normal intelligence and 1 deficit group. For young children the deficit was developmental dyslexia; for older children it was a general learning difficulty. The interference model predicts less interference through overwriting but more through confusion of whole elements for the dyslexic children than for their age-matched controls. Older children exhibited less interference through confusion of whole elements and a higher processing rate than young children, but general learning difficulty was associated with slower processing than in the age-matched control group. Furthermore, the difference between verbal and spatial updating mapped onto several meaningful dissociations of model parameters.