Foveal crowding modifies a target's properties under a brief presentation time

The perception of chromatic and achromatic visual information is combined and processed in the parvocellular stream; however, they are separate processes at the early stage of the visual cortex. In our previous study, we noted that there is difficulty discriminating the color of a letter target presented at the fovea under a crowded presentation for a short time. Visual crowding occurs when an easily identified isolated stimulus becomes very difficult to identify when it is surrounded by stimuli with similar properties. One opinion is that crowding reduces the ability to identify the target but not its features (e.g., color and texture); however, some studies indicated that the ability to recognize features is also impaired under peripheral crowding conditions. Here, we investigated whether the processing of chromatic information can be impaired at the fovea using a classic crowding experiment when tested at brief presentation times (20, 40, and 120 ms). The participants reported both the target's identity and chromaticity (dual task). We found that the target's identification and color discrimination are impaired when presented for 20-40 ms but that they recover for longer presentation times. This effect is increased when temporal backward masking is added. This finding suggests that crowding resembles masking under brief presentation times and occurs at a later processing stage, after an initial masking stage.