We consider the problem of recovering a mental target (e.g., an image of a face) that a participant has in mind from paired EEG (i.e., brain responses) and image (i.e., perceived faces) data collected during interactive sessions without access to labeled information. The problem has been previously explored with labeled data but not via self-calibration, where labeled data is unavailable. Here, we present the first framework and an algorithm, CURSOR, that learns to recover unknown mental targets without access to labeled data or pre-trained decoders. Our experiments on naturalistic images of faces demonstrate that CURSOR can (1) predict image similarity scores that correlate with human perceptual judgments without any label information, (2) use these scores to rank stimuli against an unknown mental target, and (3) generate new stimuli indistinguishable from the unknown mental target (validated via a user study, N=53). We release the brain response data set (N=29), associated face images used as stimuli data, and a codebase to initiate further research on this novel task.

Visual similarity estimation plays a fundamental role both in human cognition and multimedia information processing as it is the basis for many applications ranging from image search and recommendation to visual content generation. Existing computational models to assess visual similarity often diverge from human perception as they are typically trained solely on image data without information about how humans perceive image similarity. Here, we present an approach for learning perceptual visual similarity from brain recordings obtained via electroencephalogram (EEG). Our approach establishes a mapping between similarity reflected in the human cognitive system and a latent image representation. We evaluate the approach in two tasks. First, predicting visual distance from EEG data and second, adjusting a latent representation of a generative model to generate new images at a predicted distance from a given source image. Experiments demonstrate that the predicted distances from EEG closely align with the ground truth distances, and images generated using these predicted distances closely resemble the ground truth images. These findings open new possibilities for leveraging signals measured from human cognition to infer similarity as opposed to using only content-based models.

Generative models are powerful tools for producing novel information by learning from example data. However, the current approaches require explicit manual input to steer generative models to match human goals. Furthermore, how these models would integrate implicit, diverse feedback and goals of multiple users remains largely unexplored. Here, we present a first-of-its-kind system that produces novel images of faces by inferring human goals directly from cross-subject brain signals while study subjects are looking at example images. We report on an experiment where brain responses to images of faces were recorded using electroencephalography in 30 subjects, focusing on specific salient visual features (VFs). Preferences toward VFs were decoded from subjects' brain responses and used as implicit feedback for a generative adversarial network (GAN), which generated new images of faces. The results from a follow-up user study evaluating the presence of the target salient VFs show that the images generated from brain feedback represent the goal of the study subjects and are comparable to images generated with manual feedback. The methodology provides a stepping stone toward humans-in-the-loop image generation.

Despite recent advances in deep neural models for semantic image editing, present approaches are dependent on explicit human input. Previous work assumes the availability of manually curated datasets for supervised learning, while for unsupervised approaches the human inspection of discovered components is required to identify those which modify worthwhile semantic features. Here, we present a novel alternative: the utilization of brain responses as a supervision signal for learning semantic feature representations. Participants$(N=30)$in a neurophysiological experiment were shown artificially generated faces and instructed to look for a particular semantic feature, such as “old” or “smiling”, while their brain responses were recorded via electroencephalography (EEG). Using supervision signals inferred from these responses, semantic features within the latent space of a generative adversarial network (GAN) were learned and then used to edit semantic features of new images. We show that implicit brain supervision achieves comparable semantic image editing performance to explicit manual labeling. This work demonstrates the feasibility of utilizing implicit human reactions recorded via brain-computer interfaces for semantic image editing and interpretation.

The paper presents a novel model-based method for intelligent tutoring, with particular emphasis on the problem of selecting teaching interventions in interaction with humans. Whereas previous work has focused on either personalization of teaching or optimization of teaching intervention sequences, the proposed individualized model-based planning approach represents convergence of these two lines of research. Model-based planning picks the best interventions via interactive learning of a user memory model’s parameters. The approach is novel in its use of a cognitive model that can account for several key individual- and material-specific characteristics related to recall/forgetting, along with a planning technique that considers users’ practice schedules. Taking a rule-based approach as a baseline, the authors evaluated the method’s benefits in a controlled study of artificial teaching in second-language vocabulary learning (N = 53).

Brain-computer interfaces (BCIs) are increasingly used to perform simple operations such as a moving a cursor, but have remained of limited use for more complex tasks. In our new approach to BCI, we use brain relevance feedback to control a generative adversarial network (GAN). We obtained EEG data from 31 participants who viewed face images while concentrating on particular facial features. Following, an EEG relevance classifier was trained and propagated as feedback on the latent image representation provided by the GAN. Estimates for individual vectors matching the relevant criteria were iteratively updated to optimize an image generation process towards mental targets. A double-blind evaluation showed high performance (86.26% accuracy) against random feedback (18.71%), and not significantly lower than explicit feedback (93.30%). Furthermore, we show the feasibility of the method with simultaneous task targets demonstrating BCI operation beyond individual task constraints. Thus, brain relevance feedback can validly control a generative model, overcoming a critical limitation of current BCI approaches.