Topic: orientation selectivity

Complex spatio-temporal neural population dynamics such as traveling waves are known to exist across multiple brain regions (Lubenov & Siapas, 2009; Muller et al., 2014), and have been hypothesized to play diverse roles from information transfer (Sato et al., 2012) to long-term memory consolidation (Muller et al., 2016). To-date, however, the empirical validation of these computational hypotheses has been hindered by the lack of a flexible and efficiently trainable model of such behavior. In this work, we introduce the Locally Coupled Oscillatory Recurrent Neural Network (LocoRNN), and sho

Neurons in the primary visual cortex (V1) of rodents are selective to the orientation of the stimulus, as in other mammals such as cats and monkeys. However, in contrast with those species, their neurons display a very different type of spatial organization. Instead of orientation maps they are organized in a “salt and pepper” pattern, where adjacent neurons have completely different preferred orientations. This structure has motivated both experimental and theoretical research with the objective of determining which aspects of the connectivity patterns and intrinsic neuronal responses can exp

Neurons in the primary visual cortex (V1) encode the orientation and contrast of visual stimuli through changes in firing rate (Hubel and Wiesel, 1962). Their activity typically peaks at a preferred orientation and decays to zero at the orientations that are orthogonal to the preferred. This activity pattern is re-scaled by contrast but its shape is preserved, a phenomenon known as contrast invariance. Contrast-invariant selectivity is also observed at the population level in V1 (Carandini and Sengpiel, 2004). The mechanisms supporting the emergence of contrast-invariance at the population lev

A fundamental property of neurons in the primary visual cortex is their preference for orientation of edges. It was shown that this orientation tuning is mostly invariant under contrast changes [1], a property that is not explained by a simple feed-forward scheme [2, 3]. We designed a synthetic hybrid neural circuit to study the emergence of orientation selectivity under different thalamo-cortical connections. To this end, a computational model of the retino-thalamic pathway was combined with an in-vitro model of cortical input layer 4. The latter was either a primary culture of cortical neur