The effect of stimulus encounter rate on response decrement in jumping spiders

The inability to maintain signal detection performance with time on task, or response decrement, has been widely studied. In animals with small brains, the ability to filter out repetitive, irrelevant stimuli may prevent the nervous system from being saturated with information. However, animals must be particular to which stimuli they attend and those to ignore, as mistakes may be costly. We explored the effect of inter-stimulus interval (ISI) between repeated presentations of a visual stimulus on the response decrement of the jumping spider Trite planiceps. Jumping spiders are active visual hunters, and moving visual stimuli trigger a readily observable optomotor response. We used either an ISI of 10 or 20 s between 160 stimulus presentations, predicting that a shorter ISI would result in a steeper decrement through cognitive overstimulation, according to the resource depletion theory. While a clear response decrement was seen for both conditions, the shorter ISI resulted in a more dramatic response decrement, aligning with the resource depletion theory posited in the human-based literature.