Abstract
Humans continuously learn through experience, both implicitly (e.g., statistical learning) and explicitly (e.g., instruction). As humans learn to group distinct items into a novel category, neural patterns of activity for those items become more similar to one another and, simultaneously, more distinct from patterns of other categories. We hypothesized that we could leverage this process using neurofeedback to devise a fundamentally new way for humans to acquire conceptual knowledge. Specifically, sculpting patterns of activity in the human brain that mirror those expected to arise through learning of new visual categories may lead to enhanced perception of the sculpted categories, relative to similar, control categories that were not sculpted. To test this hypothesis, we implemented a closed-loop system for neurofeedback manipulation using fMRI measurements recorded from the human brain in real-time (every 2s) and used this method to sculpt/create new neural categories for complex visual objects. After training, participants exhibited behavioral and neural biases for the sculpted, but not for the control categories, and we observed a significant positive correlation between the increase in behavioral discrimination and the increase of neural separation of the categories. Neural sculpting provides causal evidence (through direct experimental intervention) that distributed patters of activity evoked by complex visual stimuli can be formed de novo in high-level visual cortex to create categories that didn’t previously exist in the brain or behavior. The ability to sculpt new visual and conceptual distinctions in the human brain has broad relevance to many domains of cognition such as perception, decision-making, memory, and motor control. This also broadens the possibility for non-invasive clinical intervention in humans with fMRI (e.g., brain-machine interfaces, neuroprosthetics, neurorehabilitation) and hints at the distant possibility of sculpting more extensive knowledge or complex concepts directly into the human brain, bypassing experience and instruction.