69 research outputs found
Eye fixations to figures in a four-choice situation with luminance balanced areas: Evaluating practice effects
Contingency analyses of eye movements may reveal variables that are relevant to the stimulus control of observing behavior. The present research tracked the eye movements of four adults exposed to a simultaneous discrimination among four stimuli, two two-dimensional (square and circle) and two three-dimensional (cube and cylinder) mono-chromatic figures with approximately equal luminance. On each discrimination trial, the stimuli were displayed in the four corners of a video monitor and participants chose among them by pressing corresponding keys. For two participants, choosing either cube or square (S+) was followed by the word “correct” and a 3-second inter-trial interval. Alternatively, choosing either cylinder or circle (S-) was followed by "incorrect" and a 30-second inter-trial interval. For the other two participants, contingencies were reversed. The position of the stimuli on the screen varied randomly across trials. The procedure continued for 80 trials. During these trials, discriminated choices were established. Despite the presence of both a two- and a three-dimensional S+ on each trial, responses to the three-dimensional S+ tended to prevail. Although general eye fixations tended to decrease as discrimination was established, subjects tended to observe S+ for longer durations than S-. Characteristics of the stimuli may interact with the contingencies of reinforcement in the stimulus control of observing behavior
Comparative karyotypic analysis in the Alstroemeria hookeri Lodd. (Alstroemeriaceae) complex sensu Bayer (1987)
Cytomolecular characterization of cultivars and landraces of wheat tolerant and sensitive to aluminum toxicity
Phagocytose in vivo de past. Tularensis par les leucocytes de la souris. Relations entre phagocytose et virulence de bacterie.
A chloroplast-DNA phylogeny ofKalimeris andAster, with reference to the generic circumscription
Phylogenetic relationships of JapaneseAster (Asteraceae, Astereae) sensu lato based on chloroplast-DNA restriction site mutations
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