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Görgen, K.

Publications and source records attributed to Görgen, K..

2 recordsLinked to original sources

Clutter does not affect the spatial tuning of * category representations in human object-selective cortex *

Natural vision is frequently impaired when the visual field is crowded with multiple competing objects. One common interpretation of this clutter interference is that large receptive fields in high-level visual cortex make it hard to separate objects from their surround. This view predicts less interference for spatially localized representations; therefore, classifiers trained under clutter might rely more on such localized representations. Here we tested this by measuring participants brain signals with fMRI while they viewed objects presented either alone or within cluttered arrays. Consistent with prior work, category decoding accuracy was significantly reduced in clutter. However, classifiers trained directly on cluttered displays were not spatially more localized. Instead, they generalized robustly across spatial positions, comparable to classifiers trained on isolated objects. This finding challenges the idea that clutter preferentially disrupts position-tolerant representations.

neuroscience↗

Working memory and imagery in early visual cortex

It has been suggested that visual images are memorized across brief periods of time by vividly imagining them as if they still were there. In line with this, the contents of both working memory and visual imagery are known to be encoded already in early visual cortex. If these signals in early visual areas were indeed to reflect a combined imagery and memory code, one would predict them to be weaker for individuals with reduced visual imagery vividness. Here, we systematically investigated this question in two groups of participants. Strong and weak imagers were asked to remember images across brief delay periods. We were able to reliably reconstruct the memorized stimuli from early visual cortex during the delay. Importantly, in contrast to the prediction, the quality of reconstruction was equally accurate for both strong and weak imagers. The decodable information also closely reflected behavioral precision in both groups, suggesting it could contribute to behavioral performance, even in the extreme case of completely aphantasic individuals. Our data thus suggest that working memory signals in early visual cortex can be present even in the (near) absence of phenomenal imagery.

neuroscience↗