https://www.pisavisionlab.org Research centre dedicated to frontier, interdisciplinary research of human perception Thu, 10 Sep 2026 09:09:42 +0000 en-US hourly 1 https://wordpress.org/?v=6.4.13 https://www.pisavisionlab.org/2025/08/01/pupillometric-signature-of-implicit-learning-of-statistical-regularities/ Fri, 01 Aug 2025 13:19:39 +0000 https://www.pisavisionlab.org/?p=5094

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Current Biology Animals learn about the statistical regularities of their environment by a process of implicit learning, a power- ful mechanism that may operate by mere exposure.1 Implicit learning supports processes such as speech acquisition but also learning about the spatial and temporal structure of the world more generally, which is essential for effective interaction.2 Here, we used a frequency-tagging technique to demonstrate a pupillo- metric signature of the learning of the temporal structure (pairing of numerosities) of sequential arrays. Although the numerosity pairings were unnoticed by all participants, the pupil responded clearly to their repe- tition frequency (1 Hz). Pupillometry allowed us to track the learning as it unfolded (the response became sig- nificant after less than 3 min of passive viewing), without ever directing attention to the temporal structure of the stimuli. Diverting attention away from the numerosity feature did not prevent learning, but it did affect the dynamics of the response acquisition. A clear pupillometric response was also elicited by pairing dyads of digits. In all our stimuli, the local features were randomized, implying that learning successfully generalized across stimuli that were locally different and only acquired a temporal structure once their global statistics (overall shape or numerosity) were extracted. Binda P., Terzo C., Turi M., & Burr D.C. https://www.pisavisionlab.org/2025/08/01/pupillometric-signature-of-implicit-learning-of-statistical-regularities/1-s2-0-s0960982225001459-main/https://doi.org/10.1016/j.cub.2025.02.011 https://www.pisavisionlab.org/2025/11/05/acute-supplementation-of-beta-hydroxybutyrateincreasesvisual-cortical-excitability-in-humans-a-combinedelectro-encephalographyand-magnetic-resonancespectroscopy-study/ Wed, 05 Nov 2025 14:20:26 +0000 https://www.pisavisionlab.org/?p=5213 European Journal of Neuroscience Increasing plasma levels of ketone bodies via supplementation has been recently found to modulate the neurometabolic profilein the healthy human brain. Here, we aimed to explore the physiological consequences of these neurometabolic changes by as-sessing visual cortical function. Ten young adult human volunteers (mean age 27 years, range 23–34) were orally administereda single dose of a β-hydroxybutyrate (βHB) ester (one of the main ketone bodies), and we measured neurometabolic changeafter supplementation. We used Electroencephalography (EEG) to assess cortical responsivity to visual stimuli and endogenousrhythms, and magnetic resonance spectroscopy (MRS) to quantify glutamate and GABA+ concentrations in the occipital cortex.βHB supplementation increased the amplitude of steady-state visual evoked potentials and increased resting-state EEG alphapower (8–13 Hz). These electrophysiological changes were paralleled by an increase in glutamate (but not GABA+) concentrationin the occipital cortex. The glutamate increase was correlated with the increased steady-state visual evoked potentials amplitude.This suggests that acute βHB supplementation increases the excitability of the brain cortex, as assessed neurometabolically andelectrophysiologically. We discuss how these effects of acute supplementation may differ from the long-term effects of chronicinterventions in healthy or pathological brains. Cecilia Steinwurzel, Maria Concetta Morrone, Ele Ferrannini, Francesca Frijia, Domenico Montanaro, Giuseppe Daniele, Paola Binda https://www.pisavisionlab.org/2025/11/05/acute-supplementation-of-beta-hydroxybutyrateincreasesvisual-cortical-excitability-in-humans-a-combinedelectro-encephalographyand-magnetic-resonancespectroscopy-study/eur-j-of-neuroscience-2025-steinwurzel-acute-supplementation-of-beta%e2%80%90hydroxybutyrate-increases-visual-cortical-2/https://doi.org/10.1111/ejn.70270 https://www.pisavisionlab.org/2025/11/05/short-term-monocular-deprivation-in-adult-humans-ameta-analysis-and-new-perspectives/ Wed, 05 Nov 2025 14:36:06 +0000 https://www.pisavisionlab.org/?p=5216 ["talk"] Vision Sciences Society Few hours of monocular deprivation in adult humans results in a transient shift of ocular dominance in favor of the deprived eye. This robust phenomenon has been investigated with several methodologies in 75 studies since 2011. We compiled a metaanalysis of these studies, structured following the PRISMA checklist and selectively including studies on healthy humans. Each study includes multiple experiments (approximately 180); for each, we computed a standardized effect size and, where possible, we quantified the decay rate of the effect. In the majority of studies, deprivation was achieved by covering one eye with an opaque or a translucent patch, with comparable outcomes (two-sample t(108) = -0.02, p = 0.98). Deprivation effects were mainly measured with three types of tasks: binocular cooperation, binocular competition, and monocular thresholds. Effects are larger when measured with binocular cooperation compared to binocular competition (two-sample t(100) = 4.66, p = 0.001), possibly reflecting different time windows used to report the average effects. Longer periods of deprivation induce larger (r(107) = 0.32, p = 0.001) and longer lasting effects (r(38) = 0.38, p = 0.020). Patching either eye (dominant or nondominant) does not significantly affect the outcome (two-sample t(98) = -0.74, p = 0.46). Effects are seen for both eyes; however, pooling data across studies, we find that opaque patching primarily triggers a suppression of the non-deprived eye, while translucent patching primarily boosts the deprived one (paired t(31) = 2.99, p = 0.005). A growing number of studies show that monocular deprivation effects can be mimicked by manipulations that do not impact the strength of the monocular signal, including degradation of image quality (pink noise, kaleidoscope), image inversion in space or time, or monocular delay. We conclude that the observed shift in eye dominance results from a complex interplay between bottom-up visual stimulation and top-down signals. 20/05/2025 20/05/2025 Cecilia Steinwurzel, Giacomo Pennella , Claudia Lunghi , Paola Binda https://www.pisavisionlab.org/2025/11/05/short-term-monocular-deprivation-in-adult-humans-ameta-analysis-and-new-perspectives/talk_vss-presentation/ https://www.pisavisionlab.org/2025/11/05/short-term-monocular-deprivation-changes-thalamo-cortical-connectivity-measured-with-ultra-high-field-fmriduring-visual-stimulation/ Wed, 05 Nov 2025 14:44:39 +0000 https://www.pisavisionlab.org/?p=5221 ["poster"] Vision Sciences Society In adult humans, brief periods of monocular deprivation induce ocular dominance plasticity, transiently enhancing responses to stimuli in the deprived eye in the primary visual cortex V1 (Binda et al., 2018) and the ventral pulvinar (Kurzawski et al., 2022). Prior work (Acquafredda et al., VSS2023) suggests that these changes are accompanied by a functional reorganization of visual processing circuits, particularly cortico-pulvino-cortical loops, measured in resting-state. Here we investigated how thalamocortical connectivity is modulated by visual stimulation of either eye, before and after deprivation. We acquired ultra-high-field 7T fMRI EPI sequences from 22 normally sighted adults, pre- and post-2 hours of monocular deprivation. Participants were presented with monocular band-pass noise stimuli with five contrast levels. BOLD responses were analyzed for three regions of interest: V1, lateral geniculate nucleus, and pulvinar. Their effective connectivity was assessed by Dynamic Causal Modeling (Tapas toolbox, Frassle et al., 2017). Post-deprivation, V1 evoked responses increased for the deprived eye and decreased for the non-deprived eye, and the modulation was stronger for higher contrast stimuli, consistent with a response gain change. During deprived eye stimulation, pulvinar-to-V1 effective connectivity decreased post-deprivation (like in the resting state) while the V1-pulvinar connectivity remained constant. During stimulation of the non-deprived eye, the opposite connectivity changes were observed. These results suggest that monocular deprivation produces a disconnection between pulvinar and V1, probably decreasing V1 top-down modulation. The mirror-symmetric effect for the non-deprived eye recapitulates the symmetric modulation observed psychophysically. Overall, resting state and visual-evoked results suggest that brief periods of monocular deprivation produce changes in visual processing that extend beyond local V1 processes and may reflect a reorganization of top-down visual influence in V1. 17/05/2025 17/05/2025 Miriam Acquafredda , Cecilia Barachini , Laura Biagi , Michela Tosetti , Maria Concetta Morrone , Paola Binda https://www.pisavisionlab.org/2025/11/05/short-term-monocular-deprivation-changes-thalamo-cortical-connectivity-measured-with-ultra-high-field-fmriduring-visual-stimulation/poster_vss-presentation/ https://www.pisavisionlab.org/2025/11/18/monocular-delay-during-visually-guided-actions-is-as-effective-as-monocular-deprivation-in-driving-ocular-dominance-plasticity/ Tue, 18 Nov 2025 10:37:22 +0000 https://www.pisavisionlab.org/?p=5236 Scientific Reports In normally sighted adult volunteers, applying a monocular patch for a few hours produces a short-term shift of ocular dominance in favor of the deprived eye—a phenomenon often interpreted as a form of homeostatic plasticity. We recently showed that the same effect can be elicited without eye-patching, by delaying the image in one eye (by 333 ms) over a 1 h period, during which participants engaged in a visuomotor coordination task; at the end of this period, ocular dominance shifted in favor of the delayed eye. Here we extended these findings, showing that passive exposure to the dichoptic replay of the same video with the same monocular delay did not affect ocular dominance. Moreover, we showed that the ocular dominance shift elicited by monocular delay during goal-directed actions had the same size as the effect of monocular deprivation, achieved by replacing the delayed image with a homogeneous gray screen, and that the two effects were correlated across participants. These results suggest that homeostatic plasticity is gated by a mismatch between vision in one eye and its multimodal context, and it is not necessarily linked with visual deprivation. Cecilia Steinwurzel, Giacomo Pennella, Maria Concetta Morrone, Giulio Sandini, Paola Binda https://www.pisavisionlab.org/2025/11/18/monocular-delay-during-visually-guided-actions-is-as-effective-as-monocular-deprivation-in-driving-ocular-dominance-plasticity/monocular_delay_during_visually_guided_actions_is_/https://doi.org/10.1038/s41598-025-18464-2 https://www.pisavisionlab.org/2025/12/16/the-pulvinar-regulates-plasticity-in-human-visual-cortex/ Tue, 16 Dec 2025 09:29:44 +0000 https://www.pisavisionlab.org/?p=5264 Science Advances In normally sighted human adults, 2 hours of monocular deprivation is sufficient to transiently alter ocular dominance. Here, we show that this is associated with a reduction of functional connectivity between the pulvinar and primary visual cortex (V1), selective for the pulvinar-to- V1 directionality. Across participants, the strength of the pulvinar-to- V1 connectivity was negatively correlated with the ocular dominance shift, implying less plasticity in participants with stronger influence of the pulvinar over V1. Our results support a revised model of adult V1 plasticity, where short-term reorganization is gated by modulatory signals relayed by the pulvinar. Miriam Acquafredda, Jan W. Kurzawski, Laura Biagi, Michela Tosetti, Maria Concetta Morrone, Paola Binda https://www.pisavisionlab.org/2025/12/16/the-pulvinar-regulates-plasticity-in-human-visual-cortex/sciadv-adw9988/https://doi.org/10.1126/sciadv.adw9988 https://www.pisavisionlab.org/2026/07/09/short-term-monocular-deprivation-in-healthy-humans-a-meta-analysis-and-new-perspectives/ Thu, 09 Jul 2026 09:49:21 +0000 https://www.pisavisionlab.org/?p=5389 Royal Society Starting from the early 2010s, several studies have shown that a short period of monocular deprivation in adult volunteers transiently shifts ocular dominance in favour of the deprived eye. We compiled a meta-analysis of 73 such studies and found that the shift of ocular dominance was reliably observed, although with variable effect sizes mainly associated with the duration of deprivation and the technique used for measuring ocular dominance. By contrast, the effect was remarkably stable across experimental designs (translucent versus light-tight patching of the dominant versus non-dominant eye). A qualitatively similar effect was also elicited without deprivation, by distorting the monocular image or making it task irrelevant. These results offer insights into the mechanisms underlying the ocular dominance shift, which we discuss in the light of current models and a new perspective inspired by predictive coding. This line of research allows for a new understanding of the plasticity of early visual processing, which perdures well after the end of developmental critical periods and may be used to promote recovery of visual functions. Cecilia Steinwurzel, Giacomo Pennella, Paola Binda https://www.pisavisionlab.org/2026/07/09/short-term-monocular-deprivation-in-healthy-humans-a-meta-analysis-and-new-perspectives/rspb-2025-2487/https://doi.org/10.1098/rspb.2025.2487