Memories of Visual Events Can Be Formed Without Specific Spatial Coordinates

To what extent does specific spatiotopic location accompany the remembered representation of a visual event? Feature integration theory suggests that identifying a multi-feature object requires focusing on its spatial location to integrate those features. Moreover, single unit data from anterior ventral stream neurons that fire preferentially to complex objects indicates that they have retinotopic receptive fields. It can, therefore, be predicted that location information of features of a complex stimulus is inherent in the memory of a perceived visual stimulus' representation. To evaluate this prediction, we presented participants with a brief array of characters with instructions to identify and locate the solitary letter among a set of digits. Surprisingly, analysis of trials in which the target identity was accurately reported indicated that in more than 15% of trials (i.e., in Experiments 2b & 2c) participants were almost completely uninformed about the location of the letter that they had just identified. Further analysis showed that there were two main sources of these location errors; misbinding the target to the distractors' locations and extremely poor spatial representation of the target's location to an extent that was indistinguishable from guessing. The latter finding indicates that consciously accessible representations of visual events can form despite being untethered to robust and spatially-specific representations, implying that the specific location was either not quite encoded into working memory, or was rapidly forgotten. However, when the target was marked by a single feature (color), there was no evidence of remembering the target identity without remembering its location even with strong masking.