Abstract
Purpose: To assess the role of task-relevance and explicit memory in implicit colour memory. Methods: At study, participants (N=112) reported either the colour or the category of 26 coloured line drawings. At test, black-and-white versions of objects (26 old, 26 new) were shown and participants reported the colour of the line drawing seen at study (explicit memory). Subsequently on each trial, participants were shown coloured versions of the same objects (half the same colour as during study and half colour transformed) and reported colour, category or identity (implicit memory). Results: When the colour and category of the items were correlated at study, those participants who reported category at study (N=48) evidenced reaction times for colour transformed items that were longer than those for non-transformed objects in all test conditions. Participants who reported colour at study (N=32) evidenced no influence of colour transformation on implicit memory. Furthermore, when colour and category were not correlated at study, participants who reported category at study (N=32) evidenced no influence of colour transformation on implicit memory. However, in all conditions, repetition priming was absent when explicit recall was incorrect. Conclusions: Colour appears to be encoded even when colour is irrelevant to the task at study (i.e. report category). Repetition priming occurred regardless of whether colour was relevant (i.e. report category or colour) or irrelevant to the decision at test (i.e. report identity). However, implicit recall was not independent of explicit recall in any of the conditions in these experiments.