Sensory coding and the causal impact of mouse cortex in a visual decision.

Correlates of sensory stimuli and motor actions are found in multiple cortical areas, but such correlates do not indicate whether these areas are causally relevant to task performance. We trained mice to discriminate visual contrast and report their decision by steering a wheel. Widefield calcium imaging and Neuropixels recordings in cortex revealed stimulus-related activity in visual (VIS) and frontal (MOs) areas, and widespread movement-related activity across the whole dorsal cortex. Optogenetic inactivation biased choices only when targeted at VIS and MOs,proportionally to each site's encoding of the visual stimulus, and at times corresponding to peak stimulus decoding. A neurometric model based on summing and subtracting activity in VIS and MOs successfully described behavioral performance and predicted the effect of optogenetic inactivation. Thus, sensory signals localized in visual and frontal cortex play a causal role in task performance, while widespread dorsal cortical signals correlating with movement reflect processes that do not play a causal role

Dopamine axons in dorsal striatum encode contralateral visual stimuli and choices.

The striatum plays critical roles in visually-guided decision making and receives dense axonal projections from midbrain dopamine neurons. However, the roles of striatal dopamine in visual decision making are poorly understood. We trained male and female mice to perform a visual decision task with asymmetric reward payoff, and we recorded the activity of dopamine axons innervating striatum. Dopamine axons in the dorsomedial striatum (DMS) responded to contralateral visual stimuli and contralateral rewarded actions. Neural responses to contralateral stimuli could not be explained by orienting behavior such as eye movements. Moreover, these contralateral stimulus responses persisted in sessions where the animals were instructed to not move to obtain reward, further indicating that these signals are stimulus-related. Lastly, we show that DMS dopamine signals were qualitatively different from dopamine signals in the ventral striatum, which responded to both ipsi- and contralateral stimuli, conforming to canonical prediction error signaling under sensory uncertainty. Thus, during visual decisions, DMS dopamine encodes visual stimuli and rewarded actions in a lateralized fashion, and could facilitate associations between specific visual stimuli and actions

High-yield methods for accurate two-alternative visual psychophysics in head-fixed mice

Research in neuroscience relies increasingly on the mouse, a mammalian species that affords unparalleled genetic tractability and brain atlases. Here we introduce high-yield methods for probing mouse visual decisions. Mice are head-fixed, which facilitates repeatable visual stimulation, eye tracking, and brain access. They turn a steering wheel to make two-alternative choices, forced or unforced. Learning is rapid thanks to intuitive coupling of stimuli to wheel position. The mouse decisions deliver high-quality psychometric curves for detection and discrimination, and conform to the predictions of a simple probabilistic observer model. The task is readily paired with two-photon imaging of cortical activity. Optogenetic inactivation reveals that the task requires the visual cortex. Mice are motivated to perform the task by fluid reward or optogenetic stimulation of dopaminergic neurons. This stimulation elicits larger number of trials and faster learning. These methods provide a platform to accurately probe mouse vision and its neural basis

High-yield methods for accurate two-alternative visual psychophysics in head-fixed mice

Research in neuroscience increasingly relies on the mouse, a mammalian species that affords unparalleled genetic tractability and brain atlases. Here, we introduce high-yield methods for probing mouse visual decisions. Mice are head-fixed, facilitating repeatable visual stimulation, eye tracking, and brain access. They turn a steering wheel to make two alternative choices, forced or unforced. Learning is rapid thanks to intuitive coupling of stimuli to wheel position. The mouse decisions deliver high-quality psychometric curves for detection and discrimination and conform to the predictions of a simple probabilistic observer model. The task is readily paired with two-photon imaging of cortical activity. Optogenetic inactivation reveals that the task requires mice to use their visual cortex. Mice are motivated to perform the task by fluid reward or optogenetic stimulation of dopamine neurons. This stimulation elicits a larger number of trials and faster learning. These methods provide a platform to accurately probe mouse vision and its neural basis

Robert Gliński as a portraitist of minors’ prostitution. ”piggies” on the border

Po zrušení kontrol na mezistátní hranici začala příhraniční prostituce v Evropě vzkvétat. Na prodeji sexuálních služeb se stálé více podílejí nezletilí. Problém "prasátek" je obecně tiché drama dětí, pro které je prostituce způsob výdělku, a které je jen velmi zřídka odhaleno. Cílem této analýzy je upozornění na širokou škálu chování se známkami podmíněné prostituce. Tuto obtížnou problematiku vyportrétoval Robert Gliński. Díky jeho práci můžeme nahlédnout do prostředí nezletilých chlapců provozujících prostituci.Prostytucja na ekranach kin gości od długiego już czasu. Polska kinematografia nie podejmuje jednak tematu prostytucji homoseksualnej. W swoim opracowaniu autorka stara się zaprezentować jeden ze najnowszych punktów widzenia tego procederu z udziałem nieletnich dzięki oku kamery, z problematyką pogranicza w tle. Film Świnki to kunsztownie zrealizowana historia o bolesnym aspekcie życia i dorastania młodzieży we współczesnym świecie – zdominowanym przez konsumpcję, brak ograniczeń moralnych, wolnym od ograniczeń (granic). Przedstawiona tu analiza ma na celu przybliżenie problematyki dziecięcej prostytucji uprawianej na obszarach przygranicznych i skonfrontowanie jej z obrazem filmowym wyreżyserowanym przez jednego z najbardziej wybitnych twórców kina polskiego. Niniejszy tekst pozwoli poznać motywy podejmowania płatnych usług seksualnych, sposoby prewencji oraz walki z takim postępowaniem, być może uzmysłowi skalę nierządu z udziałem dzieci.After the abolition of border checks at international borders, prostitution began to flourish in Europe. Minors have been increasingly involved in the sale of sexual services. The problem of "piggies" is generally a quiet drama of children for whom prostitution is a way to earn their living; only rarely is it detected. The aim of this analysis is to highlight a wide range of behavioural signs of conditional prostitution. This difficult issue has been described by Robert Glinski. Due to his work, we can look into the world of underage boys engaged in prostitution.Nach der Abschaffung der Grenzkontrollen erfährt die Prostitution entlang der Grenzen eine Blütezeit. Am Verkauf sexueller Dienste beteiligen sich immer mehr Minderjährige. Beim Problem der „Schweinchen“ handelt es sich im Allgemeinen um ein stilles Drama der Kinder, für welche die Prostitution eine Verdienstmöglichkeit darstellt. Dieses Drama wird nur sehr selten aufgedeckt. Ziel dieser Analyse ist es, auf die breite Skala des Umgangs mit den Anzeichen der bedingten Prostitution aufmerksam zu machen. Diese schwierige Problematik wurde von Robert Gliński portraitiert. Seine Arbeit ermöglicht uns einen Einblick in das Milieu der minderjährigen Jungen, welche der Prostitution nachgehen

Mapping perceptual decisions to cortical regions

Perceptual decisions involve a complex interaction of several brain areas. The neocortex is thought to play a major role in this process, but it is unclear which cortical areas are causally involved, and what their individual roles are. To explore this problem, we trained head-fixed mice to perform a two-alternative unforced-choice visual discrimination task. Mice were rewarded with water for turning a wheel to indicate which of two stimuli had higher contrast, or for holding the wheel still if no stimuli were present. We developed a hierarchical Bayesian model of the choice behaviour and used this to quantify mouse behaviour in terms of perceptual states such as choice biases and stimulus sensitivities. We also used this model framework to quantify how these perceptual states vary across individual mice and across sessions. Using widefield calcium imaging, we found robust sequential activation in primary visual, secondary visual, secondary motor, primary motor and somatosensory cortices in response to stimulus presentation. Optogenetic inactivation revealed that only the first two regions: visual (VIS) and secondary motor (MOs) areas, were causally relevant. VIS inactivation was effective earlier than MOs inactivation, which suggests a sequential causal role for these regions. We observed a surprising effect of VIS inactivation which could only be explained by a downstream subtractive process which integrates information between the two hemispheres. We tested this idea by developing a mechanistic model which was fit to widefield fluorescence data, using the same Bayesian hierarchical framework used earlier. In this model, VIS activity enhances the decision variable associated with contraversive movements and suppresses the decision variable associated with ipsiversive movements. By contrast, activity in MOs enhances both. This model could predict average psychometric behaviour, trial-by-trial variation in choices within a stimulus condition, as well as simulate the effect of optogenetic inactivation. This thesis therefore shines light on the cortical contributions towards visual discrimination behaviour. This work has implications for the neural processes underlying perceptual decision making more broadly

A dedicated binding mechanism for the visual control of movement

The human motor system is remarkably proficient in the online control of visually guided movements, adjusting to changes in the visual scene within 100 ms [1-3]. This is achieved through a set of highly automatic processes [4] translating visual information into representations suitable for motor control [5, 6]. For this to be accomplished, visual information pertaining to target and hand need to be identified and linked to the appropriate internal representations during the movement. Meanwhile, other visual information must be filtered out, which is especially demanding in visually cluttered natural environments. If selection of relevant sensory information for online control was achieved by visual attention, its limited capacity [7] would substantially constrain the efficiency of visuomotor feedback control. Here we demonstrate that both exogenously and endogenously cued attention facilitate the processing of visual target information [8], but not of visual hand information. Moreover, distracting visual information is more efficiently filtered out during the extraction of hand compared to target information. Our results therefore suggest the existence of a dedicated visuomotor binding mechanism that links the hand representation in visual and motor systems. © 2014 The Authors