Visual illusions in geology
Examples of visual illusions in the laboratory are well documented, but what about illusions that occur during field observation of geological structures? In this article I discuss a study involving geologists and non-geologists and define some of the problems that may arise during geological field and laboratory work.
‘Peak Preference’ and Waveform Perception
Because the perception of waveforms has been relatively neglected in vision research, one phenomenon of waveform perception, the parsing of waves into peak-shaped rather than trough-shaped segments, is examined. It is suggested that this so-called ‘peak preference’ is a grouping rule which can determine figure—background segregation in some circumstances. It appears to resist explanation in terms of the spatial-filtering properties of the visual system. For a complete explanation of peak preference, the ecological significance for actions that wave stimuli would normally have in the natural setting has to be considered.
Serial and parallel classification.
The recognition of complex stimuli may be achieved by either of two strategies. Stimulus characteristics may be noted in turn (serial classification) or simultaneously (parallel classification). Two experiments are reported which attempt to determine which method is adopted with novel stimuli and whether a change in strategy occurs with practice. It was concluded that an initial mode of classification which was probably serial gives way to parallel classification after extended practice. The advantages of parallel classification in recognition are discussed.