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Lifestyle dietary interventions are an essential practice in treating obesity, hence neural factors that may assist in predicting individual treatment success are of great significance. Here, in a prospective, open-label, three arms study, we examined the correlation between brain resting-state functional connectivity measured at baseline and weight loss following 6 months of lifestyle intervention in 92 overweight participants. We report a robust subnetwork composed mainly of sensory and motor cortical regions, whose edges correlated with future weight loss. This effect was found regardless of intervention group. Importantly, this main finding was further corroborated using a stringent connectivity-based prediction model assessed with cross-validation thus attesting to its robustness. The engagement of senso-motor regions in this subnetwork is consistent with the over-sensitivity to food cues theory of weight regulation. Finally, we tested an additional hypothesis regarding the role of brain-gastric interaction in this subnetwork, considering recent findings of a cortical network synchronized with gastric activity. Accordingly, we found a significant spatial overlap with the subnetwork reported in the present study. Moreover, power in the gastric basal electric frequency within our reported subnetwork negatively correlated with future weight loss. This finding was specific to the weight loss related subnetwork and to the gastric basal frequency. These findings should be further corroborated by combining direct recordings of gastric activity in future studies. Taken together, these intriguing results may have important implications for our understanding of the etiology of obesity and the mechanism of response to dietary intervention as well as to interoceptive perception. Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070

One of the most fundamental concepts in theoretical neuroscience is that of an attractor neural network, in which recurrent synaptic connectivity constraints the joint activity of neurons into a highly restricted repertoire of population activity patterns. In continuous attractor networks, these activity patterns span a continuous, low-dimensional manifold. I will survey two recent works from my group that are related to this concept. The first work is concerned with fixational eye drifts, a form of eye motion that occurs between saccades and is characterized by smooth, yet random, diffusive-like motion. This motion is tiny compared to saccadic eye motion, yet it is highly consequential for high-acuity vision. Even though fixational drift has been identified at least as early as the 19th century, its mechanistic origins have remained completely unknown. We hypothesize that the main drive for fixational drifts arises in diffusive motion along a line-attractor memory network - the oculomotor network, which is responsible for maintaining a fixed activation of the ocular muscles between saccades. I will present evidence in support of this hypothesis, coming from electrophysiology in monkeys and from theoretical modeling. The second work is concerned with the ability of a single recurrent neural network to express activity patterns that span multiple yet distinct continuous manifolds, a question that has been of interest in the context of spatial coding, across multiple environments, in area CA3 of the hippocampus. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070