Neural population

…Despite this interdependence, the neural basis of working memory and perceptual decision-making have largely been studied separately. Thus, how the brain flexibly combines sensory information with information in memory to form decisions remains unknown. To study this interaction, we developed a novel behavioral task in which monkeys hold a set of color images in working memory as context,

Despite the diversity of neural responses, the brain is highly structured both at anatomical and functional levels. Neurons in different brain areas exhibit different response profiles (large-scale anatomical organization), and within brain areas, the neurons can sometimes be grouped together into specialized subpopulations (categorical representations). Organization can also be found at the level of the representational geometry in the activity space, typically in the form of low-dimensional structure (e.g. disentangled abstract representations). However, it is unclear how the geometry in the

Spatial navigation is normally yoked to the motor actions responsible for travel. Neural populations in CA1 exert influence on navigational outcomes, but this coupling makes it challenging to isolate abstract representations of travel from concrete motor actions. In this work, we present an experimental paradigm that uses a hippocampal closed-loop Brain-Machine Interface (BMI) to decouple running locomotion from the cognitive map. This BMI associates neural activity with locations on a 1D Virtual Reality (VR) track, and then translates those locations into contextually appropriate actions (Fig

…In contrast, the neural mechanisms controlling the selection of representations held ‘in mind’, in working memory, are unknown. In this talk, I will present evidence that the prefrontal cortex controls working memory by selectively enhancing and transforming the contents of working memory. In particular, I will show how the neural rep

…a form of neural multiplexing in the time domain (Caruso et al., 2018). However, it is not known (a) whether such fluctuations occur specifically when two distinct objects are present and not in other cases, and (b) how fluctuations in individual neurons might be coordinated with one anot

…emerge from structure in neural populations and from biologically plausible learning rules. First, I will introduce an analytic theory that connects geometric structures that arise from neural res

In this lecture, I will present our recent progress on three aspects of population responses in the primary visual cortex: encoding local stimulus attributes, electrical microstimulation and higher visual function. In the first part I will focus on population encoding and reconstruction of contour shapes in V1 and the comparison between monkey and mouse visual responses. In the second part of the talk I will present the effects of microstimulation on neural population in V1 and the relation to evoked saccades. In the final part of the talk I will discuss top-down influences in V1 and their re

…to analyze the computational role of population activity as opposed to single neuron activity. Recent work on a variety of cortical areas suggests that neural function may be built on the activation of population-wide activity patterns, the neural modes, rather than on the independent modulation of individual neural activity. These neural modes, the dominant covariation patterns within the neural population, define a low dimensional neural manifold that captures m

…and cricket to primate – responses of neural populations can be quite successfully read out using a measure neural population activity termed the population vector. However, despite its successes, detailed analyses have shown that the standard population vector discards substantial amounts of information contained in the responses of a neural population, and so is unlikely to accurately describe how signal communication between parts of the nervous system. I will describe recent theoretical results showing how to modify the population vect