A dialog engine configured to answer a sequence of questions related to an image. An attention module residing in the dialog engine includes an attention retrieval process and a tentative attention process. The attention retrieval process retrieves a relevant attention map that may have previously been used to answer a previous query. The tentative attention process generates a tentative attention map based on an image and other input parameters. The attention module combines the relevant attention map and the tentative attention map to generate a fused attention map. Based on the fused attention map, the dialog engine generates a response to the query. Finally, the dialog engine stores the fused attention map in an attention memory for use in answering future queries.