Andrew M Wikenheiser

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Hippocampal information processing is discretized by oscillations, and the ensemble activity of place cells is organized into temporal sequences bounded by theta cycles. Theta sequences represent time-compressed trajectories through space. Their forward-directed nature makes them an intuitive candidate mechanism for planning future trajectories, but their(More)
Place cell firing patterns in the rat hippocampus are often organized as sequences. Sequences falling within cycles of the theta (6-10 Hz) local field potential (LFP) oscillation represent segments of ongoing behavioral trajectories. Sequences expressed during sharp wave ripple (SWR) complexes represent spatial trajectories through the environment, in both(More)
Pyramidal cells in the rodent hippocampus often exhibit clear spatial tuning. Theories of hippocampal function suggest that these "place cells" implement multiple, independent neural representations of position (maps), based on different reference frames or environmental features. Consistent with the "multiple maps" theory, previous studies have shown that(More)
Laboratory studies of decision making often take the form of two-alternative, forced-choice paradigms. In natural settings, however, many decision problems arise as stay/go choices. We designed a foraging task to test intertemporal decision making in rats via stay/go decisions. Subjects did not follow the rate-maximizing strategy of choosing only food items(More)
Tolman proposed that complex animal behavior is mediated by the cognitive map, an integrative learning system that allows animals to reconfigure previous experience in order to compute predictions about the future. The discovery of place cells in the rodent hippocampus immediately suggested a plausible neural mechanism to fulfill the 'map' component of(More)
Sequences of neural activity representing paths in an environment are expressed in the rodent hippocampus at three distinct time scales, with different hypothesized roles in hip-pocampal function. As an animal moves through an environment and passes through a series of place fields, place cells activate and deactivate in sequence, at the time scale of the(More)
Disrupting the reactivation of hippocampal neurons during sleep impairs memory consolidation in rats. However, the functional importance of reactivation during awake states is unknown. An experiment in which awake reactivation was disrupted suggests that this phenomenon could adaptively guide behavior by linking previous learning with the current state of(More)
Ensemble activity in the hippocampus is often arranged in temporal sequences of spiking. Early theoretical and experimental work strongly suggested that hippocampal sequences functioned as a neural mechanism for memory consolidation , and recent experiments suggest a causal link between sequences during sleep and mnemonic processing. However, in addition to(More)
After publication of our article examining foraging strategies in rats (1), we were made aware of an additional model that could potentially explain some aspects of the observed behavior. The foraging model developed in the paper (eq. 1) does not include a travel time term, and thus computes the food intake rate only over the delay periods at feeder sites.(More)