Strategy guides feature recall of a single object in working memory task

Abstract

Over past couple of decades our understanding of visual working memory (VWM), and working memory in general, has been predominantly in line with the capacity debate. We recently opened a new line of inquiry regarding the recall of a single object to go beyond the capacity debate, and showed that a series of feature probe questions about a single object yields poorer recall later in the sequence (Sengupta et al, 2020). In the current work we focused on another aspect of sequential feature recall - mainly regarding whether recall can be improved by asking the same question twice. To that end, we chose to focus on two features - color and location, and we contrasted repeat and non-repeat (from the standpoint of feature questions) trials in a series of two experiments. In repeat trials either color or location would be probed twice consecutively. In non-repeat trials color and location probes were presented one after the other in random order. In all trials the stimulus was a small colored oriented line presented for 1 sec in a location within 4o of visual angle. The recall of color and location were mapped onto continuous variable like Sengupta et al, 2020 - for instance, color recall was mapped onto a color wheel. In the first experiment, we used an unaltered color wheel when the color question was repeated. For the second experiment, we used a rotated color wheels for two consecutive color recall trials. We observed an increase in recall error for both repeat and non-repeat condition for location when the probe was at the second question in both experiments. However, color recall error did not increase for second repeat question condition in Experiment 1 as opposed to the non-repeat condition. On the other hand, in Experiment 2 we observed the expected increase in recall error for both repeat and non repeat condition for color probe at the second question. This maybe due to the fact that participants used an anchoring strategy in Experiment 1 by remembering where they clicked on the color wheel in the first question. The rotation of color wheel in second experiment destroys the anchor leading to the aforementioned result. The results show that trying to recall the same feature again leads to degradation of recall accuracy for both color and location, and human beings may use different strategies for recall in working memory tasks.