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HE, J.

Publications and source records attributed to HE, J..

2 recordsLinked to original sources

Theta sweeps accelerate cognitive map learning by broadcasting information to unvisited regions

To support flexible behavior, animals need to learn map like representations of environments from limited experiences, but the underlying neural mechanisms remain unclear. Here, we propose that theta sweeps, a prominent feature in the activities of grid and place cells during active movement, can broadcast acquired sensory information to swept unvisited regions, accelerating cognitive map learning. To test this idea, we built a network of direction, grid, and place cell modules, in which theta modulation and firing rate adaptation generate theta sweeps, while Hebbian plasticity enables place cells to bind environmental observations. Simulations and ablations showed that the dorsal ventral grid organization produces multiscale, independent sweeps broadcasting acquired sensory information to a broad, fan shaped unvisited area, enabling unvisited regions to build place environment associations. The model further suggests that declining theta power as the environment becomes familiar acts as an annealing process, shifting from learning general information about the environment to making local refinements. The model makes three testable predictions: strong theta modulation accelerates early learning, environments with broader spatial correlations favor longer theta sweeps, and theta sweeps progressively shorten as environments become familiar. Together, our results support theta sweeps as a mechanism for accelerating cognitive map learning from limited explorations, and it sheds light on developing brain inspired algorithms for building world models.

neuroscience↗

Pulsatilla hezijianensis, (Ranunculaceae), a new species from Beijing, China.

Pulsatilla hezijianensis H.Y. Wu & L. Xie, a new species of Ranunculaceae from Hezijian Village (Beijing, China), is described. This taxon resembles P. sukaczevii and P. tenuiloba in its finely dissected pinnate leaves but is distinguished by its smaller stature (3-15 cm tall), shorter scapes, smaller fruit heads, and sepals with white inner surfaces and pale blue outer surfaces. Molecular phylogenetic analyses based on nuclear (nrITS) and plastid markers (rbcL, accD-psaI, trnL intron) revealed that the Hezijian population forms a distinct clade, sister to P. tenuiloba but with significant genetic divergence. Morphological comparisons with allied species, coupled with its distribution and phenology, support its recognition as a new species. The restricted distribution and small population size warrant its conservation status as Critically Endangered (CR) under IUCN criteria.

evolutionary biology↗