Technical restrictions of computer-manipulated visual stimuli and display units for studying animal behaviour

Computer-manipulated visual stimuli are a well-established tool to experimentally study animal behaviour. They provide the opportunity to manipulate single or combined visual stimuli selectively, while other potentially confounding variables remain constant. A wide array of different presentation methods of artificial stimuli has been used in recent research. Furthermore, a wide range of basic hardware and software has been used to conduct experiments. The outcomes of experimental trials using computer-manipulated visual stimuli differed among studies. Failing or contradictory results were mostly discussed in a behavioural and ecological context. However, the results sometimes may be basically flawed due to methodological traps in the experimental design. Based on characteristics and restrictions of technical standards, we discuss which kinds of computer stimuli and visual display units are available today and their suitability for experimental trials when studying animal behaviour. A computer-manipulated stimulus displayed by a certain visual display unit may be accurate to investigate behaviour in a specific species, if various preconditions are met. However, simply due to technical characteristics of the visual display unit, the set-up may be unsuitable for other test species. Thus, future research should critically apply the included technique, with respect to both the intended kind of stimulus and the species under investigation. If these preconditions are met, computer-manipulated stimuli provide a high degree of standardization and the potential to display visual signals without losing a crucial amount of information from the native data.