Figure 1

Schematics of various object recognition tasks with 2 objects. (A) Standard novel object recognition in the same environment with 1 exposure phase (left), a delay and a novel object present at the test phase (right). The highlighted grey circle denotes expected novelty-based discrimination. Lower case letters denote objects. (B) Object-recency task in the same environment with 2 exposure phases (left and middle) and the test phase (right). The highlighted grey circle denotes expected novelty-based discrimination on the object least recently seen. (C) Object-place-context task in two different environments (i.e., contexts) with 2 exposure phases (left and middle). Test phase can be made in the 1st context (upper right) or test can be made in the 2nd context (lower right). In test in the 1st context trials, the highlighted blue circle can denote novelty discrimination of integrated object-place-context association or the highlighted red circle can denote novelty discrimination of object in place recency (note that discrimination is ignorant to context, see B). In test in the 2nd context trials, the highlighted yellow circle can denote novelty discrimination of integrated object-place-context or novelty discrimination of object-place recency (they are overlapping). (D,E) Other 2 objects/exposure/contexts tasks which are susceptible to a context-based versus recency-based strategy where F is applicable. (F) Strategy scatterplot for 2 object/context/exposure object recognition tasks. Based on (C–E) one can average discrimination ratio scores separately for both for test in the 1st context trials and test in the 2nd context trials and plot them for each animal. The average context D2 for trials when test was made in the 1st context on the x-axis, and for trials when test was made in the 2nd context on the y-axis. Thus, one can form angular data and use directional statistics, which can enhance interpretive power if animals are behaving differently to chance. Context^novel/Recency^novel denote exploration on the basis of object related novelty preference. Context^familiar/Recency^familiar denote exploration on the basis of object related familiarity preference.