Z Bohdanecký

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Eye fixation duration during discrimination of pairs of simultaneously presented computer generated random textures differing in 'grain' has been analyzed. Of the shortest duration are fixation periods preceded and followed by local saccades over the same texture and those preceded by local saccade and followed by crossing saccade shifting the eye to the(More)
Tracing movements (hand-following the stationary contours of three two-dimensional figures: square, triangle and circle by means of a computer mouse-operated lightspot) were analyzed during five consecutive days. All three figures consisting of four (square, circle) or three (triangle) segments had the same circumference. Three parameters were chosen to(More)
The process of selection of target points during voluntary eye movements when contoured polygonal shapes with open and closed angles are observed was analysed in humans by means of an eye recording technique. It has been found for both types of stimuli that the majority of fixation points where located at angles and that the mean value of distribution was(More)
Central and occipital EEGs were recorded during one-dimensional eye-hand tracking in humans. A negative slow potential shift followed the commitment of tracking errors at electrode O1 and their correction both at O1 and C3. Error commitments were also followed by a relative decrease in alpha and beta-band power at O1, whereas their corrections followed a(More)
In humans sitting in darkness with open eyes the presence of EEG alpha and non-alpha epochs was detected automatically and the threshold of detection of a dim visual stimulus was measured under both conditions. No differences in threshold were found. However, the reaction times for stimulus detection during alpha epochs were significantly longer than during(More)
Subjects were required to track a target consisting of two vertical bars moving with either a constant or a sinusoidally modulated speed across an oscilloscope screen with a joystick-controlled light-spot. Either target size (distance between bars-size guided tasks) or velocity of the target movement (velocity guided tasks), varied throughout different(More)
We describe a package of programs in Turbo Pascal which enables us to present six different versions of the modified Sternberg memory test and to evaluate the subject's performance. The program starts presenting a brief series of randomly generated visual stimuli (digits/colors) which are to be memorized, followed by the target stimulus. The series could(More)