Rules : the basis of morality...?

Most theories of moral knowledge, throughout history, have focused on behavior-guiding rules. Those theories attempt to identify which rules are the morally valid ones, and to identify the source or ground of that privileged set. The variations on this theme are many and familiar. But there is a problem here. In fact, there are several. First, many of the higher animals display a complex social order, one crucial to their biological success, and the members of such species typically display a sophisticated knowledge of what is and what is not acceptable social behavior—but those creatures have no language at all. They are unable even to express a single rule, let alone evaluate it for moral validity. Second, when we examine most other kinds of behavioral skills—playing basketball, playing the piano, playing chess—we discover that it is surpassingly difficult to articulate a set of discursive rules, which, if followed, would produce a skilled athlete, pianist, or chess master. And third, it would be physically impossible for a biological creature to identify which of its myriad rule are relevant to a given situation, and then apply them, in real time, in any case. All told, we would seem to need a new account of how our moral knowledge is stored, accessed, and applied. The present paper explores the potential, in these three regards, of recent alternative models from the computational neurosciences. The possibilities, it emerges, are considerable

Chronically-implanted Neuropixels probes enable high yield recordings in freely moving mice

The advent of high-yield electrophysiology using Neuropixels probes is now enabling researchers to simultaneously record hundreds of neurons with remarkably high signal to noise. However, these probes have not been well-suited to use in freely moving mice. It is critical to study neural activity in unrestricted animals for many reasons, such as leveraging ethological approaches to study neural circuits. We designed and implemented a novel device that allows Neuropixels probes to be customized for chronically-implanted experiments in freely moving mice. We demonstrate the ease and utility of this approach in recording hundreds of neurons during an ethological behavior across weeks of experiments. We provide the technical drawings and procedures for other researchers to do the same. Importantly, our approach enables researchers to explant and reuse these valuable probes, a transformative step which has not been established for recordings with any type of chronically-implanted probe

Integration of Direction Cues Is Invariant to the Temporal Gap between Them

Many decisions involve integration of evidence conferred by discrete cues over time. However, the neural mechanism of this integration is poorly understood. Several decision-making models suggest that integration of evidence is implemented by a dynamic system whose state evolves toward a stable point representing the decision outcome. The internal dynamics of such point attractor models render them sensitive to the temporal gaps between cues because their internal forces push the state forward once it is dislodged from the initial stable point. We asked whether human subjects are as sensitive to such temporal gaps. Subjects reported the net direction of stochastic random dot motion, which was presented in one or two brief observation windows (pulses). Pulse strength and interpulse interval varied randomly from trial to trial. We found that subjects' performance was largely invariant to the interpulse intervals up to at least 1 s. The findings question the implementation of the integration process via mechanisms that rely on autonomous changes of network state. The mechanism should be capable of freezing the state of the network at a variety of firing rate levels during temporal gaps between the cues, compatible with a line of stable attractor states

Chronically-implanted Neuropixels probes enable high yield recordings in freely moving mice: dataset

The advent of high-yield electrophysiology using Neuropixels probes is now enabling researchers to simultaneously record hundreds of neurons with remarkably high signal to noise. However, these probes have not been well-suited to use in freely moving mice. It is critical to study neural activity in unrestricted animals for many reasons, such as leveraging ethological approaches to study neural circuits. We designed and implemented a novel device that allows Neuropixels probes to be customized for chronically-implanted experiments in freely moving mice. We demonstrate the ease and utility of this approach in recording hundreds of neurons during an ethological behavior across weeks of experiments. We provide the technical drawings and procedures for other researchers to do the same. Importantly, our approach enables researchers to explant and reuse these valuable probes, a transformative step which has not been established for recordings with any type of chronically-implanted probe