How animals discriminate between stimulus magnitudes: a meta-analysis

To maximize their fitness, animals must often discriminate between stimuli differing in magnitude (such as size, intensity, or number). Weber’s Law of proportional processing states that stimuli are compared based on the proportional difference in magnitude, rather than the absolute difference. Weber’s Law implies that when stimulus magnitudes are higher, it becomes harder to discriminate small differences between stimuli, leading to more discrimination errors. More generally, we can refer to a correlation between stimulus magnitude and discrimination error frequency as a magnitude effect, with Weber’s law being a special case of the magnitude effect. If more discrimination errors are made when stimulus magnitudes are higher, this could affect how signals evolve. However, the strength and prevalence of the magnitude effect across species has never previously been tested. Here, we conducted a meta-analysis to quantify the strength of the magnitude effect across studies, finding that, on ..., , , # How animals discriminate between stimuli: a meta-analysis

## Files provided in this dataset

### Supplementary data

* **Supplementary data 1:** Summarises the data extracted from each dataset which was selected for inclusion, with the following headings:
* Reference: Label for this study, corresponding to the Y axis of Figure 3(a)
* Citation
* Species, Common name
* Stimulus: description of the stimulus for which discrimination ability was tested
* Modality: sensory modality (electroreception, hearing, smell, taste, touch, vision)
* Choice: choice type (whether the preference for the chosen stimulus was innate or conditioned)
* Task: task type (whether the subject had to determine which stimulus had a higher magnitude or simply whether the stimuli differed)
* Weber's law: whether the study mentioned Weber's law
* k, Lower bound, Upper bound: fitted value of *k* and its 95% confidence intervals. This is NA where a model could not be fitted.
* Model fitted, Model t...,