We are capable of retaining a large variety of visual content in working memory, ranging from simple low-level features to complex naturalistic stimuli. Maintenance of visual information in working memory is accompanied by memory-specific activity across the entire cortical sheet from early visual areas to frontal cortex. Interference between memory content and distractors shapes these representations, as does the passage of time. Here, we bring together experts from cognitive psychology and neuroscience trying to understand the cortical and cognitive mechanisms of short-term memory. Using behavioral work, TMS, single-cell recordings, fMRI, and convolutional neural networks, they assess the representational nature of working memory storage and its interaction with the environment.  
First, Pablo Grassi asks whether activity in sensory cortex is necessary for the maintenance of visual information. He will present results from three experiments investigating whether TMS pulses applied over visual cortex interfere with working memory performance for low-level features. Michael Wolff will then show that V1 neurons reverse preference between the processing and short-term maintenance of natural images, evident in both spontaneous and evoked (“pinged”) spiking activity. This suggests that neural adaptation acts like a short-term memory buffer in the early sensory cortex. Next, Anna Zier asks which brain regions represent how low-level visual features (like color and motion) are bound into a more complex object in working memory. Using fMRI decoding, she demonstrates that trial-specific binding information can be identified from memory-related activity in early visual cortex (V1–V4). Then, Anastasia Kiyonaga uses CNN derived similarity measures in natural images to show that low-level and high-level interference uniquely affect working memory performance. Intriguingly, interference effects during working memory are inversely related to long term memory recollection, suggesting competition with immediate memory can strengthen longer-term memory. Finally, Joana Seabra shows that during visual working memory several cortical regions utilize categorical, semantic, and spatial representational formats to maintain simple low-level stimuli in a robust fashion.