https://www.pisavisionlab.org Research centre dedicated to frontier, interdisciplinary research of human perception Thu, 10 Sep 2026 08:30:20 +0000 en-US hourly 1 https://wordpress.org/?v=6.4.13 https://www.pisavisionlab.org/2023/07/24/effect-of-fasting-on-short-term-visual-plasticity-in-adult-humans/ Mon, 24 Jul 2023 18:59:24 +0000 https://www.pisavisionlab.org/?p=4491 Eur J Neurosci. 2023 Jan; 57(1): 148–162. Brain plasticity and function is impaired in conditions of metabolic dysregulation, such as obesity. Less is known on whether brain function is also affected by transient and physiological metabolic changes, such as the alternation between fasting and fed state. Here we asked whether these changes affect the transient shift of ocular dominance that follows short‐term monocular deprivation, a form of homeostatic plasticity. We further asked whether variations in three of the main metabolic and hormonal pathways affected in obesity (glucose metabolism, leptin signalling and fatty acid metabolism) correlate with plasticity changes. We measured the effects of 2 h monocular deprivation in three conditions: post‐absorptive state (fasting), after ingestion of a standardised meal and during infusion of glucagon‐like peptide‐1 (GLP‐1), an incretin physiologically released upon meal ingestion that plays a key role in glucose metabolism. We found that short‐term plasticity was less manifest in fasting than in fed state, whereas GLP‐1 infusion did not elicit reliable changes compared to fasting. Although we confirmed a positive association between plasticity and supraphysiological GLP‐1 levels, achieved by GLP‐1 infusion, we found that none of the parameters linked to glucose metabolism could predict the plasticity reduction in the fasting versus fed state. Instead, this was selectively associated with the increase in plasma beta‐hydroxybutyrate (B‐OH) levels during fasting, which suggests a link between neural function and energy substrates alternative to glucose. These results reveal a previously unexplored link between homeostatic brain plasticity and the physiological changes associated with the daily fast‐fed cycle. S. Animali, C. Steinwurzel, A.Dardano, V. Sancho‐Bornez,S. Del Prato, M. C. Morrone, G. Daniele, P. Binda https://www.pisavisionlab.org/2023/07/24/effect-of-fasting-on-short-term-visual-plasticity-in-adult-humans/effect-of-fasting-on-short-term-visual-plasticity-in-adult-human/https://onlinelibrary.wiley.com/doi/10.1111/ejn.15873 https://www.pisavisionlab.org/2023/08/25/development-of-local-global-preference-in-vision-and-haptics/ Fri, 25 Aug 2023 09:23:05 +0000 https://www.pisavisionlab.org/?p=4526 Journal of Vision April 2023, Vol.23, 6 We aimed to advance our understanding of local-global preference by exploring its developmental path within and across sensory modalities: vision and haptics. Neurotypical individuals from six years of age through adulthood completed a similarity judgement task with hierarchical haptic or visual stimuli made of local elements (squares or triangles) forming a global shape (a square or a triangle). Participants chose which of two probes was more similar to a target: the one sharing the global shape (but different local shapes) or the one with the same local shapes (but different global shape). Across trials, we independently varied the size of the local elements and that of the global configuration—the latter was varied by manipulating local element density while keeping their numerosity constant. We found that the size of local elements (but not global size) modulates the effects of age and modality. For stimuli with smaller local elements, the proportion of global responses increased with age and was similar for visual and haptic stimuli. However, for stimuli made of our largest local elements, the global preference was reduced or absent, particularly in haptics, regardless of age. These results suggest that vision and haptics progressively converge toward similar global preference with age, but residual differences across modalities and across individuals may be observed, depending on the characteristics of the stimuli. C. Tortelli, I. Senna, P. Binda, M. O. Ernst https://www.pisavisionlab.org/2023/08/25/development-of-local-global-preference-in-vision-and-haptics/i1534-7362-23-4-6_1682420351-62276/https://doi.org/10.1167/jov.23.4.6 https://www.pisavisionlab.org/2023/08/25/short-term-monocular-deprivation-in-adult-humans-alters-pulvino-cortical-functional-connectivity-measured-withresting-state-fmri-at-ultra-high-field/ Fri, 25 Aug 2023 09:49:09 +0000 https://www.pisavisionlab.org/?p=4531 ["poster"] Vision Science Society meeting 2023 In adult humans, a brief period (2 hours) of monocular deprivation induces a form of homeostatic plasticity. Stimuli in the deprived eye are transiently boosted, shifting perceptual ocular dominance towards the deprived eye and modulating visually evoked fMRI responses. Here we demonstrate that monocular deprivation also produces a functional reorganization of visual processing circuits as revealed by changes in functional connectivity. Ultra-high field 7T fMRI EPI resting-state sequences (with two TRs, 3000 and 1000 ms) were acquired in 20 normally sighted adult participants, before and after the application of a translucent patch on the dominant eye for two hours. During the acquisitions, participants kept their eyes closed. Functional connectivity was measured by correlating BOLD signals in each cortical voxel with those in a subcortical “seed” area: ventral (visual) pulvinar and LGN. The correlation was computed after performing temporal filtering (bandpass 0.01 - 0.1 Hz) and nuisance regression (fMRI time-course in a mask covering white matter and CSF voxels). Comparing functional connectivity before and after monocular deprivation, we found decreased connectivity of early visual areas (V1-V3) with the ventral pulvinar, but unchanged connectivity with LGN. These results suggest that the ventral pulvinar plays an important role in broadcasting signals that modulate sensory processing and that may implement the homeostatic plasticity of neural function. 19/05/2023 25/05/2023 M. Acquafredda, L. Biagi, M. Tosetti, M.C. Morrone, P. Binda https://doi.org/10.1167/jov.23.9.5237 https://www.pisavisionlab.org/2023/09/15/measuring-the-reliability-of-binocular-rivalry/ Fri, 15 Sep 2023 13:15:01 +0000 https://www.pisavisionlab.org/?p=4565 Journal of Vision September 2023, Vol.23, 5 Binocular rivalry is a widely used tool in sensory and cognitive neuroscience to investigate different aspects of vision and cognition. The dynamics of binocular rivalry (e.g., duration of perceptual dominance phases and mixed percept proportions) differ across individuals; based on rivalry dynamics, it is also possible to calculate an index of ocular dominance (by comparing the perceptual dominance of the images in the two eyes). In this study, we investigated the reliability of binocular rivalry dynamics using different methods for dichoptic stimulation and different rivalry stimuli. For the three main indices we defined (ocular dominance, phase durations and mixed percept proportions), we found a high test–retest reliability across sessions. Moreover, the test–retest reliability of the ocular dominance index was predictable from its internal consistency, supporting its stability over time. Phase durations and mixed percept proportions, in contrast, had worse test–retest reliability than expected based on internal consistency, indicating that these parameters are susceptible to state-dependent changes. Our results support the use of the ocular dominance index and binocular rivalry in the measurement of sensory eye dominance and its plasticity, but advise caution when investigating the association between phase durations or mixed percepts and stable characteristics like psychological traits or disorders. M. Acquafredda; I. D. Sarı; C. Steinwurzel; C. Lunghi; P. Binda https://www.pisavisionlab.org/2023/09/15/measuring-the-reliability-of-binocular-rivalry/measuring-the-reliability-of-binocular-rivalry/https://doi.org/10.1167/jov.23.10.5 https://www.pisavisionlab.org/2023/09/25/serial-dependence-inperception/ Mon, 25 Sep 2023 08:54:09 +0000 https://www.pisavisionlab.org/?p=4579 Annu. Rev. Psychol. 2024. 75:9.1–9.26 Much evidence has shown that perception is biased towards previously presented similar stimuli, an effect recently termed serial dependence. Serial dependence affects nearly every aspect of perception, often causing gross perceptual distortions, especially for weak and ambiguous stimuli. Despite unwanted side-effects, empirical evidence and Bayesian modeling show that serial dependence acts to improve efficiency and is generally beneficial to the system. Consistent with models of predictive coding, the Bayesian priors of serial dependence are generated at high levels of cortical analysis, incorporating much perceptual experience, but feed back to lower sensory areas. These feedback loops may drive oscillations in the alpha range, linked strongly with serial dependence. The discovery of top-down predictive perceptual processes is not new, but the new, more quantitative approach characterizing serial dependence promises to lead to a deeper understanding of predictive perceptual processes and their underlying neural mechanisms. G.M. Cicchini, K. Mikellidou, D.C. Burr https://www.pisavisionlab.org/2023/09/25/serial-dependence-inperception/ps75ch09_burr001-0261/https://doi.org/10.1146/annurev-psych-021523- 104939 https://www.pisavisionlab.org/2023/09/25/the-role-of-neural-oscillations-in-visuo-motor-communication-at-the-time-of-saccades/ Mon, 25 Sep 2023 09:11:46 +0000 https://www.pisavisionlab.org/?p=4586 Neuropsychologia, 108682 Saccadic eye-movements are fundamental for active vision, allowing observers to purposefully scan the environment with the high-resolution fovea. In this brief perspective we outline a series of experiments from our laboratories investigating the role of eye-movements and their consequences to active perception. We show that saccades lead to suppression of visual sensitivity at saccadic onset, and that this suppression is accompanied by endogenous neural oscillations in the delta range. Similar oscillations are initiated by purposeful hand movements, which lead to measurable changes in responsivity in area V1, and in the connectivity with motor area M1. Saccades also lead to clear distortions in apparent position, but only for verbal reports, not when participants respond with rapid pointing, consistent with the action of two separate visual systems in neurotypical adults. At the time of saccades, serial dependence, the positive influence on perception of previous stimulus attributes (such as orientation) is particularly strong. Again, these processes are accompanied by neural oscillations, in the alpha and low beta range. In general, oscillations seem to be tightly linked to serial dependence in perception, both in auditory judgments (around 10 Hz), and for visual judgements of face gender (14 Hz for female, 17 Hz for male). Taken together, the studies show that neural oscillations play a fundamental role in dynamic, active vision. Burr, D. C., & Morrone, M. C. https://www.pisavisionlab.org/2023/09/25/the-role-of-neural-oscillations-in-visuo-motor-communication-at-the-time-of-saccades/1-s2-0-s0028393223002166-main-2/https://doi.org/10.1016/j.neuropsychologia.2023.108682 https://www.pisavisionlab.org/2023/10/09/attention-cueing-in-rivalry-insights-from-pupillometry-2/ Mon, 09 Oct 2023 13:31:09 +0000 https://www.pisavisionlab.org/?p=4609 ["invited talk"] Attention Lab - University of Utrecht Miriam Acquafredda

Utrecht

52.0907374 5.1214201 14 ChIJNy3TOUNvxkcR6UqvGUz8yNY Utrecht Utrecht UT Netherlands NL https://www.pisavisionlab.org/2023/10/09/active-vision-shapes-ocular-dominance/ Mon, 09 Oct 2023 13:43:07 +0000 https://www.pisavisionlab.org/?p=4619 ["live talk"] European Conference on Visual Perception 27/08/2023 31/10/2023 Paola Binda, Cecilia Steinwurzel, Giulio Sandini, Maria Concetta Morrone https://www.pisavisionlab.org/2023/10/16/short-term-monocular-deprivation-in-adult-humans-alterspulvino-cortical-functional-connectivity-measured-withresting-state-fmri-at-ultra-high-field/ Mon, 16 Oct 2023 13:24:01 +0000 https://www.pisavisionlab.org/?p=4631 ["poster"] Vision Sciences Society meeting 2023 n adult humans, a brief period (2 hours) of monocular deprivation induces a form of homeostatic plasticity. Stimuli in the deprived eye are transiently boosted, shifting perceptual ocular dominance towards the deprived eye and modulating visually evoked fMRI responses. Here we demonstrate that monocular deprivation also produces a functional reorganization of visual processing circuits as revealed by changes in functional connectivity. Ultra-high field 7T fMRI EPI resting-state sequences (with two TRs, 3000 and 1000 ms) were acquired in 20 normally sighted adult participants, before and after the application of a translucent patch on the dominant eye for two hours. During the acquisitions, participants kept their eyes closed. Functional connectivity was measured by correlating BOLD signals in each cortical voxel with those in a subcortical “seed” area: ventral (visual) pulvinar and LGN. The correlation was computed after performing temporal filtering (bandpass 0.01 - 0.1 Hz) and nuisance regression (fMRI time-course in a mask covering white matter and CSF voxels). Comparing functional connectivity before and after monocular deprivation, we found decreased connectivity of early visual areas (V1-V3) with the ventral pulvinar, but unchanged connectivity with LGN. These results suggest that the ventral pulvinar plays an important role in broadcasting signals that modulate sensory processing and that may implement the homeostatic plasticity of neural function. 19/05/2023 24/05/2023 Miriam Acquafredda, Laura Biagi, Michela Tosetti, Maria Concetta Morrone, Paola Binda https://www.pisavisionlab.org/2023/10/16/short-term-monocular-deprivation-in-adult-humans-alterspulvino-cortical-functional-connectivity-measured-withresting-state-fmri-at-ultra-high-field-2/ Mon, 16 Oct 2023 13:36:34 +0000 https://www.pisavisionlab.org/?p=4642 ["poster"] SIF National Congress The Italian Society of Physiology 06/09/2023 08/09/2023 Miriam Acquafredda, Laura Biagi, Michela Tosetti, Maria Concetta Morrone, Paola Binda https://www.pisavisionlab.org/2023/10/16/pupillometric-signature-of-implicit-learning/ Mon, 16 Oct 2023 13:49:37 +0000 https://www.pisavisionlab.org/?p=4647 ["talk"] Vision Sciences Society meeting 2023 Far from being a mere reflection of ambient light, the diameter of our eye-pupils has been shown to track the contents of visual perception, the direction of attention and the occurrence of unexpected sensory events. Here we show that changes in pupil-size provide a reliable index of implicit learning, reflecting statistical structures even when they are neither consciously perceived nor within the focus of attention. We used a frequency-tagging temporal segmentation paradigm (Schwiedrzik and Sudmann, J.Neurosci 2020), where sequences of visual images (refreshed at 2 Hz) are displayed either in random order or in pairs, with odd-trial images reliably predicting even-trial images (pairs cycling at 1 Hz). Stimuli were either two-digit numbers, or arrays of lines: in the paired-images condition for arrays, the only information predicting even from odd trials was the numerosity of the array, as the arrangement and orientation of the lines was always randomly resampled on every trial. For both digits and arrays of lines, pupil diameter in N=8 observers oscillated at 1 Hz in the paired-images condition, tracking the statistical structure of the stimulus sequence. For the arrays, the oscillation emerged only when numerosity varied in steps larger than the discrimination threshold (suggesting a potential technique to measure numerosity acuity). Participants were never asked to consciously discriminate the paired sequences and were unaware of the difference between the paired and random conditions. The 1-Hz oscillation remained strong even when attention was directed to an irrelevant feature (the orientation of the lines, which was never predictive from odd to even trials). In summary, we extracted a pupillometric signature of neural prediction in paired images, providing a novel, objective, and seamless way to quantify the automatic and implicit structuring of sensory flow into meaningful units. 19/05/2023 24/05/2023 Paola Binda; Chiara Terzo; Marco Turi; David C. Burr https://www.pisavisionlab.org/2023/10/31/active-vision-gates-ocular-dominance-plasticity-in-human-adults/ Tue, 31 Oct 2023 11:44:34 +0000 https://www.pisavisionlab.org/?p=4673 Curr Biol . 2023 Oct 23;33(20):R1038-R1040 Primary visual cortex (V1) retains a form of plasticity in adult humans: a brief period of monocular deprivation induces an enhanced response to the deprived eye, which can stabilize into a consolidated plastic change1,2 despite unaltered thalamic input3. This form of homeostatic plasticity in adults is thought to act through neuronal competition between the representations of the two eyes, which are still separate in primary visual cortex4,5. During monocular occlusion, neurons of the deprived eye are thought to increase response gain given the absence of visual input, leading to the post-deprivation enhancement. If the decrease of reliability of the monocular response is crucial to establish homeostatic plasticity, this could be induced in several different ways. There is increasing evidence that V1 processing is affected by voluntary action, allowing it to take into account the visual effects of self-motion6, important for efficient active vision7. Here we asked whether ocular dominance homeostatic plasticity could be elicited without degrading the quality of monocular visual images but simply by altering their role in visuomotor control by introducing a visual delay in one eye while participants actively performed a visuomotor task; this causes a discrepancy between what the subject sees and what he/she expects to see. Our results show that homeostatic plasticity is gated by the consistency between the monocular visual inputs and a person's actions, suggesting that action not only shapes visual processing but may also be essential for plasticity in adults. C. Steinwurzel, M.C. Morrone, G. Sandini, P. Binda https://www.pisavisionlab.org/2023/10/31/active-vision-gates-ocular-dominance-plasticity-in-human-adults/active-vision-gates-ocular-dominance-plasticity-in-human-adults/https://doi.org/10.1016/j.cub.2023.08.062 https://www.pisavisionlab.org/2023/11/10/autistic-individuals-show-less-grouping-induced-bias-in-numerosity-judgments/ Fri, 10 Nov 2023 08:53:25 +0000 https://www.pisavisionlab.org/?p=4678 Frontiers in Child and Adolescent Psychiatry, 2, 1–9. Introduction: When items are connected together, they tend to be perceived as an integrated whole rather than as individual dots, causing a strong underestimation of the numerosity of the ensemble. Previous evidence on grouping-induced biases of numerosity has shown a dependency on autistic-like personality traits in neurotypical adults, with a weaker tendency for grouping into meaningful segmented objects in individuals with strong autistic traits. Here we asked whether this result would generalize to the autistic population. Methods: Twenty-two adults with a diagnosis of Autism Spectrum Disorder (ASD) and 22 matched neurotypical controls judged the numerosity of clouds of dot-pairs connected by thin lines. Results: Results showed no significant group difference in discrimination precision, suggesting that both groups were equally capable performing the task. However, while connecting pairs of dots at moderate numerosities caused large changes in apparent numerosity in the neurotypical controls, particularly those with low autistic-like traits, it had little effect in the group of autistic participants, suggesting significant differences in numerosity estimation between autistic and neurotypical perception. Consistent with earlier studies, the magnitude of the effect covaried strongly with AQ-defined autistic traits in the neurotypical range, reinforcing the idea that autistic traits predict the strength of grouping. Discussion: These results provide strong support for the theories of autistic perception that highlight dissimilarities in global vs. local processing, and open the door to study grouping mechanisms indirectly, by asking participants to report on the apparent numerosity rather than on the grouping organization per se. Pomè, A., Karaminis, T., & Burr, D. C. https://www.pisavisionlab.org/2023/11/10/autistic-individuals-show-less-grouping-induced-bias-in-numerosity-judgments/frcha-02-1202032/https://doi.org/10.3389/frcha.2023.1202032 https://www.pisavisionlab.org/2023/11/10/serial-dependence-in-orientation-judgments-at-the-time-of-saccades/ Fri, 10 Nov 2023 08:57:23 +0000 https://www.pisavisionlab.org/?p=4682 Journal of Vision, 23(7), 7. We actively seek information from the environment through saccadic eye movements, necessitating continual integration of presaccadic and postsaccadic signals, which are displaced on the retina by each saccade. We tested whether trans-saccadic integration may be related to serial dependence (a measure of how perceptual history influences current perception) by measuring how viewing a presaccadic stimulus affects the perceived orientation of a subsequent test stimulus presented around the time of a saccade. Participants reproduced the position, and orientation of a test stimulus presented around a 16° saccade. The reproduced position was mislocalized toward the saccadic target, agreeing with previous work. The reproduced orientation was attracted toward the prior stimulus and regressed to the mean orientation. These results suggest that both short- and long-term past information affects trans-saccadic perception, most strongly when the test stimulus is presented perisaccadically. This study unites the fields of serial dependence and trans-saccadic perception, leading to potential new insights of how information is transferred and accumulated across saccades. Xie, X.-Y., Morrone, M. C., & Burr, D. C. https://www.pisavisionlab.org/2023/11/10/serial-dependence-in-orientation-judgments-at-the-time-of-saccades/i1534-7362-23-7-7_1688985193-96744/https://doi.org/10.1167/jov.23.7.7 https://www.pisavisionlab.org/2023/11/10/serial-dependence-improves-performance-and-biases-confidence-based-decisions/ Fri, 10 Nov 2023 09:01:15 +0000 https://www.pisavisionlab.org/?p=4686 Journal of Vision, 23(7), 5. Perception depends on both the current sensory input and on the preceding stimuli history, a mechanism referred to as serial dependence (SD). One interesting, and somewhat controversial, question is whether serial dependence originates at the perceptual stage, which should lead to a sensory improvement, or at a subsequent decisional stage, causing solely a bias. Here, we studied the effects of SD in a novel manner by leveraging on the human capacity to spontaneously assess the quality of sensory information. Two noisy-oriented Gabor stimuli were simultaneously presented along with two bars of the same orientation as the Gabor stimuli. Participants were asked to choose which Gabor stimulus to judge and then make a forced-choice judgment of its orientation by selecting the appropriate response bar. On all trials, one of the Gabor stimuli had the same orientation as the Gabor in the same position on the previous trial. We explored whether continuity in orientation and position affected choice and accuracy. Results show that continuity of orientation leads to a persistent (up to four back) accuracy advantage and a higher preference in the selection of stimuli with the same orientation, and this advantage accumulates over trials. In contrast, analysis of the continuity of the selected position indicated that participants had a strong tendency to choose stimuli in the same position, but this behavior did not lead to an improvement in accuracy. Maldonado Moscoso, P. A., Burr, D. C., & Cicchini, G. M. https://www.pisavisionlab.org/2023/11/10/serial-dependence-improves-performance-and-biases-confidence-based-decisions/i1534-7362-23-7-5_1689331525-45538/https://doi.org/10.1167/jov.23.7.5 https://www.pisavisionlab.org/2023/11/10/the-role-of-non-numerical-information-in-the-perception-of-temporal-numerosity/ Fri, 10 Nov 2023 09:05:26 +0000 https://www.pisavisionlab.org/?p=4690 Frontiers in Psychology, 14, 1197064. Numerosity perception refers to the ability to make rapid but approximate estimates of the quantity of elements in a set (spatial numerosity) or presented sequentially (temporal numerosity). Whether numerosity is directly perceived or indirectly recomputed from non-numerical features is a highly debated issue. In the spatial domain, area and density have been suggested as the main parameters through which numerosity would be recomputed. In the temporal domain, stimuli duration and temporal frequency could be similarly exploited to retrieve numerosity. By adapting a psychophysical technique previously exploited in the spatial domain, we investigated whether temporal visual numerosity is directly perceived. Adult participants observed sequences of visual impulses sampled from a stimulus space spanning several levels of temporal frequency and duration (and hence numerosity), and then reproduced the sequence as accurately as possible via a series of keypresses. Crucially, participants were not asked to reproduce any particular property (such as number of impulses) but were free to choose any available cue (such as total duration, or temporal frequency). The results indicate that while the overall sequence duration was barely considered, numerosity and temporal frequency were both spontaneously used as the main cues to reproduce the sequences, with a slight but significant dominance of numerosity. Overall, the results are in line with previous literature suggesting that numerosity is directly encoded, even for temporal sequences, but a non-numerical feature (temporal frequency) is also used in reproducing sequences. Cicchini, G. M., Anobile, G., Burr, D. C., Marchesini, P., & Arrighi, R. https://www.pisavisionlab.org/2023/11/10/the-role-of-non-numerical-information-in-the-perception-of-temporal-numerosity/fpsyg-14-1197064/https://doi.org/10.3389/fpsyg.2023.1197064 https://www.pisavisionlab.org/2023/11/10/active-vision-how-you-look-reflects-what-you-are-looking-for/ Fri, 10 Nov 2023 09:32:47 +0000 https://www.pisavisionlab.org/?p=4709 Current Biology: CB, 33(8), R303–R305 While we fixate an object, our eyes are never stationary but constantly drifting, with miniature movements traditionally thought to be random and involuntary. A new study shows that the orientation of such drift in humans is actually not random but is influenced by the task demands to improve performance. Benedetto, A., & Kagan, I. https://www.pisavisionlab.org/2023/11/10/active-vision-how-you-look-reflects-what-you-are-looking-for/piis0960982223003007/https://doi.org/10.1016/j.cub.2023.03.012 https://www.pisavisionlab.org/2023/11/19/action-shaped-perception-towards-a-reunification-of-two-systems/ Sun, 19 Nov 2023 11:38:17 +0000 https://www.pisavisionlab.org/?p=4783 PhD Thesis In this dissertation I investigated the relationship between action and perception in the processing of Space, Time and Numerosity. In the first chapter the most prominent literature on the topic is reviewed to introduce the conceptual framework in which the experimental paradigms were developed. In 2003 Vincent Walsh proposed A Theory of Magnitude (ATOM) which posits that space, time and numerosity share a common processing mechanism rooted in our need for information about the spatial and temporal structure of the external world. According to Walsh, we could learn about the association between the fundamental magnitudes through our interaction with the environment, as in real-life settings they often correlate with each other (for instance, a higher number of items takes up a larger space and requires a longer time to be retrieved). One of the functional consequences of the ATOM theory would be a perceptual interference across magnitudes, which would result in judgments regarding one magnitude being biased by another irrelevant one. In the second chapter of this thesis, I demonstrate that the interaction between duration and numerosity is task-dependent: participants’ judgments about stimulus duration were influenced by stimulus numerosity only when tested with a discrimination task. This suggests that the cross-magnitude interaction predicted by the ATOM Theory does not occur at the processing level, but it is dependent by the kind of task (ie. comparisons) the observer is required to perform. This, in turn, suggests that the interplay between time and numerosity occurs at a later stage after perceptual processing as for example, at the decisional level. In chapter 3 I report evidence for a new cross-modal after-effect, revealing that the metric with which the visual system computes the relative spatial position of objects is shared with the motor system. A few seconds of mid-air self-produced tapping movements (adaptation) yielded a robust compression of the apparent separation of dot pairs subsequently displayed around the tapping region. As the influence of tapping on numerosity and duration perception had been previously demonstrated, these results offer clear evidence for a generalized interaction between the motor system and the processing of perceptual magnitude information in line with the ATOM Theory predictions (see above). After demonstrating the influence of upper-body movements on magnitude perception, Chapter 4 is dedicated to the investigation of the influence of lower-body movements on the perception of duration and numerosity. As already reported in previous literature, I found that running systematically interferes with duration perception as it causes an overestimation of perceived time. However, in order to overcome some of the discrepancies in the existing literature that might be caused by methodological differences, I applied a standardized motor paradigm to different time ranges and sensory modalities. This allowed me to generalize the effect induced by running on duration perception across visual and auditory modalities and across sub-second and supra-second duration ranges. On the other hand, I found no distortion of numerosity judgments because of running, suggesting that this effect does not generalize across magnitudes. Lastly, I focused on the importance of Peripersonal (PPS) and Extrapersonal (EPS) space in the investigation of the relationship between action and perception, which is often overlooked, but remains a vital component in the theoretical framework of ATOM theory. Indeed, action needs proximity with its target, and there is evidence of perceptual networks dedicated exclusively to PPS. As is often the case with magnitude perception, time has been the first domain investigated while taking into account the influence of stimulus distance. One of the research lines carried out during the PhD was aimed at generalizing the effects of PPS and EPS on time to numerosity perception. My results clearly indicate numerosity perception relies less on stimulus distance than time does, with participants showing the same perceptual precision and accuracy in both EPS and PPS. In the last chapter I applied the psychophysical methodologies I got familiar to during the PHD to study perception in a virtual reality (VR) environment that allow to test perceptual processes in highly ecological settings to make VR always more important in future research of perceptual neuroscience. This study was conducted in collaboration with the Center for Applied Neuroscience of the University of Cyprus where I spent 7 months during my period abroad. My aim was to validate in VR a paradigm that has been replicated multiple times in real world settings to measure the size of participants’ PPS. Following this, I also experimented a tool-training method aimed at reshaping participants’ PPS. My results show that, similarly to real world settings, a short period of tool-training is sufficient to cause a significant enlargement of the PPS. This result is of primary importance, as it shows for the first time that PPS in Virtual Reality has similar characteristics of Peripersonal space as measured in real life settings, thus offering evidence towards a valuable validation of VR as a tool to study the characteristics of Peripersonal space. Irene Petrizzo https://www.pisavisionlab.org/2023/11/19/action-shaped-perception-towards-a-reunification-of-two-systems/phdthesis_petrizzo/https://hdl.handle.net/2158/1321552 https://www.pisavisionlab.org/2023/11/19/similar-effect-of-running-on-visual-and-auditory-time-perception-in-the-ranges-of-milliseconds-and-seconds/ Sun, 19 Nov 2023 13:45:52 +0000 https://www.pisavisionlab.org/?p=4787 Frontiers in Psychology Introduction: The ability to accurately encode events’ duration is of critical importance for almost all everyday activities, yet numerous factors have been reported to robustly distort time perception. One of these is physical activity (i.e., running, walking) but, partly due to the variety of methodologies employed, a full comprehension of the role of exercise on the encoding of time has still to be achieved. Methods: Here we tackle the issue with a multifaceted approach by measuring the effect of vigorous running with a time generalization task for visual and auditory stimuli in the range of milliseconds (0.2–0.8 s) as well as seconds (1–4 s). At baseline, participants performed both the encoding and decoding at rest while in the experimental conditions the decoding was performed while running. Results: Our results indicate that physical activity in both duration ranges (sub-second and seconds) was expanded during running regardless of the sensory modality used to present the stimuli. Despite this generalized effect of running on perceived duration, we found evidence for the existence of independent timing mechanisms: (1) the perceptual biases induced by running in the two temporal regimes were uncorrelated, (2) sensory precision levels (Weber fraction) were higher for stimuli in the seconds range, (3) sensory precision levels were higher for auditory than for visual stimuli, but only within the sub-second range. Discussion: Overall, our results support previous findings suggesting (at least partially) separate timing mechanisms for short/long durations and for visual and auditory stimuli. However, they also indicate that physical activity affects all these temporal modules, suggesting a generalized interaction—via generalized and shared resources—between the motor system and the brain time mechanisms. Irene Petrizzo, Eleonora Chelli, Tommaso Bartolini, Roberto Arrighi, Giovanni Anobile https://www.pisavisionlab.org/2023/11/19/similar-effect-of-running-on-visual-and-auditory-time-perception-in-the-ranges-of-milliseconds-and-seconds/fpsyg-14-1146675-1/https://doi.org/10.3389/fpsyg.2023.1146675 https://www.pisavisionlab.org/2023/11/19/reshaping-the-peripersonal-space-in-virtual-reality/ Sun, 19 Nov 2023 15:15:02 +0000 https://www.pisavisionlab.org/?p=4791 Scientific Reports (under review) Peripersonal space (PPS) refers to the space around us that lies within reach, in which most of our interactions with the environment occur. However, the PPS is not a static bubble surrounding our body. Rather, it can be dynamically reshaped in size, for instance as a consequence of the use of tools extending the arm’s reach. Here we employed a visuo-tactile detection task in an immersive VR environment to measure the size of participants’ PPS before and after different kinds of tool training. A short training period in which participants pulled objects from the Extrapersonal space (EPS) towards themselves via a tool was effective in enlarging the PPS, a result that nicely complements previous studies carried out in real life studies. However, no signicant change in PPS size was achieved via training with other motor routines such as pulling, hammering or shooting, each of which involving a different kind of interaction between the agent and the targets. Taken together, our results suggest that the reshaping of the PPS is a complex phenomenon in which the kind of motor routines exploited to interact with the surrounding objects, plays a critical role. Irene Petrizzo, Kyriaki Mikellidou, Savvas Avraam, Marios Avraamides and Roberto Arrighi https://www.pisavisionlab.org/2023/11/19/reshaping-the-peripersonal-space-in-virtual-reality/dc33a18f-ab8c-464b-814d-1d05893af17a/https://doi.org/10.21203/rs.3.rs-3101264/v1 https://www.pisavisionlab.org/2023/11/19/sensorimotor-mechanisms-selective-to-numerosity-evidence-from-individual-differences/ Sun, 19 Nov 2023 15:21:08 +0000 https://www.pisavisionlab.org/?p=4795 eLife We have previously shown that after few seconds of adaptation by finger-tapping, the perceived numerosity of spatial arrays and temporal sequences of visual objects displayed near the tapping region is increased or decreased, implying the existence of a sensorimotor numerosity system (Anobile et al., 2016). To date, this mechanism has been evidenced only by adaptation. Here, we extend our finding by leveraging on a well-established covariance technique, used to unveil and characterize ‘channels’ for basic visual features such as colour, motion, contrast, and spatial frequency. Participants were required to press rapidly a key a specific number of times, without counting. We then correlated the precision of reproduction for various target number presses between participants. The results showed high positive correlations for nearby target numbers, scaling down with numerical distance, implying tuning selectivity. Factor analysis identified two factors, one for low and the other for higher numbers. Principal component analysis revealed two bell-shaped covariance channels, peaking at different numerical values. Two control experiments ruled out the role of non-numerical strategies based on tapping frequency and response duration. These results reinforce our previous reports based on adaptation, and further suggest the existence of at least two sensorimotor number channels responsible for translating symbolic numbers into action sequences. Giovanni Anobile, Irene Petrizzo, Daisy Paiardini, David Burr, Guido Marco Cicchini https://www.pisavisionlab.org/2023/11/19/sensorimotor-mechanisms-selective-to-numerosity-evidence-from-individual-differences/elife-92169-v1/https://doi.org/10.7554/eLife.92169.3 https://www.pisavisionlab.org/2023/11/19/the-symmetry-induced-numerosity-illusion-depends-on-visual-attention/ Sun, 19 Nov 2023 15:48:02 +0000 https://www.pisavisionlab.org/?p=4799 Scientific Reports Symmetry is an important and strong cue we rely on to organize the visual world. Although it is at the basis of objects segmentation in a visual scene, it can sometimes bias our perception. When asked to discriminate numerical quantities between symmetric and asymmetric arrays, individuals tend to underestimate the number of items in the symmetric stimuli. The reason for this underestimation is currently unknown. In this study we investigated whether the symmetry‑induced numerosity underestimation depends on perceptual grouping mechanisms by depriving attentional resources. Twenty‑six adults judged the numerosity of dot arrays arranged symmetrically or randomly, while ignoring a visual distractor (single task) or while simultaneously judging its color and orientation (dual‑task). Diverting attention to the concurrent color–orientation conjunction task halved the symmetry‑induced numerosity underestimation. Taken together these results showed that the bias in numerosity perception of symmetric arrays depends—at least partially—on attentional resources and suggested that it might originate from the recruitment of attentional dependent incremental grouping mechanisms. Paula Andrea Maldonado Moscoso, Giuseppe Maduli, Giovanni Anobile, Roberto Arrighi and Elisa Castaldi https://www.pisavisionlab.org/2023/11/19/the-symmetry-induced-numerosity-illusion-depends-on-visual-attention/s41598-023-39581-w/ https://doi.org/10.1038/s41598-023-39581-w https://www.pisavisionlab.org/2023/11/19/eeg-signature-of-grouping-strategies-in-numerosity-perception/ Sun, 19 Nov 2023 16:18:05 +0000 https://www.pisavisionlab.org/?p=4803 Frontiers in Neuroscience The moment we see a group of objects, we can appreciate its numerosity. Our numerical estimates can be imprecise for large sets (>4 items), but they become much faster and more accurate if items are clustered into groups compared to when they are randomly displaced. This phenomenon, termed groupitizing, is thought to leverage on the capacity to quickly identify groups from 1 to 4 items (subitizing) within larger sets, however evidence in support for this hypothesis is scarce. The present study searched for an electrophysiological signature of subitizing while participants estimated grouped numerosities exceeding this range by measuring event-related potential (ERP) responses to visual arrays of different numerosities and spatial configurations. The EEG signal was recorded while 22 participants performed a numerosity estimation task on arrays with numerosities in the subitizing (3 or 4) or estimation (6 or 8) ranges. In the latter case, items could be spatially arranged into subgroups (3 or 4) or randomly scattered. In both ranges, we observed a decrease in N1 peak latency as the number of items increased. Importantly, when items were arranged to form subgroups, we showed that the N1 peak latency reflected both changes in total numerosity and changes in the number of subgroups. However, this result was mainly driven by the number of subgroups to suggest that clustered elements might trigger the recruitment of the subitizing system at a relatively early stage. At a later stage, we found that P2p was mostly modulated by the total numerosity in the set, with much less sensitivity for the number of subgroups these might be segregated in. Overall, this experiment suggests that the N1 component is sensitive to both local and global parcelling of elements in a scene suggesting that it could be crucially involved in the emergence of the groupitizing advantage. On the other hand, the later P2p component seems to be much more bounded to the global aspects of the scene coding the total number of elements while being mostly blind to the number of subgroups in which elements are parsed. Camilla Caponi, Paula Andrea Maldonado Moscoso, Elisa Castaldi, Roberto Arrighi and Paolo Grasso https://www.pisavisionlab.org/2023/11/19/eeg-signature-of-grouping-strategies-in-numerosity-perception/fnins-17-1190317/ https://doi.org/10.3389/fnins.2023.1190317 https://www.pisavisionlab.org/2023/11/19/math-difficulties-in-attention-deficit-hyperactivity-disorder-do-not-originate-from-the-visual-number-sense/ Sun, 19 Nov 2023 16:26:59 +0000 https://www.pisavisionlab.org/?p=4807 Frontiers in Human Neuroscience There is ample evidence from literature and clinical practice indicating mathematical difficulties in individuals with ADHD, even when there is no concomitant diagnosis of developmental dyscalculia. What factors underlie these difficulties is still an open question. Research on dyscalculia and neurotypical development suggests visual perception of numerosity (the number sense) as a building block for math learning. Participants with lower numerosity estimation thresholds (higher precision) are often those with higher math capabilities. Strangely, the role of numerosity perception in math skills in ADHD has been neglected, leaving open the question whether math difficulties in ADHD also originate from a deficitary visual number sense. In the current study we psychophysically measured numerosity thresholds and accuracy in a sample of children/adolescents with ADHD, but not concomitant dyscalculia (N = 20, 8–16 years). Math abilities were also measured by tasks indexing different mathematical competences. Numerosity performance and math scores were then compared to those obtained from an age-matched control group (N = 20). Bayesian statistics indicated no difference between ADHD and controls on numerosity perception, despite many of the symbolic math tasks being impaired in participants with ADHD. Moreover, the math deficits showed by the group with ADHD remained substantial even when numerosity thresholds were statistically regressed out. Overall, these results indicate that math difficulties in ADHD are unlikely to originate from an impaired visual number sense. Giovanni Anobile, Mariaelisa Bartoli, Gabriele Masi, Annalisa Tacchi and Francesca Tinelli https://www.pisavisionlab.org/2023/11/19/math-difficulties-in-attention-deficit-hyperactivity-disorder-do-not-originate-from-the-visual-number-sense/fnhum-16-949391-1/https://doi.org/10.3389/fnhum.2022.949391 https://www.pisavisionlab.org/2023/12/07/fast-discrimination-of-fragmentary-images-the-role-of-local-optimal-information/ Thu, 07 Dec 2023 17:07:22 +0000 https://www.pisavisionlab.org/?p=4817 Frontiers in Human Neuroscience, 17 In naturalistic conditions, objects in the scene may be partly occluded and the visual system has to recognize the whole image based on the little information contained in some visible fragments. Previous studies demonstrated that humans can successfully recognize severely occluded images, but the underlying mechanisms occurring in the early stages of visual processing are still poorly understood. The main objective of this work is to investigate the contribution of local information contained in a few visible fragments to image discrimination in fast vision. It has been already shown that a specific set of features, predicted by a constrained maximum- entropy model to be optimal carriers of information (optimal features), are used to build simplified early visual representations (primal sketch) that are sufficient for fast image discrimination. These features are also considered salient by the visual system and can guide visual attention when presented isolated in artificial stimuli. Here, we explore whether these local features also play a significant role in more natural settings, where all existing features are kept, but the overall available information is drastically reduced. Indeed, the task requires discrimination of naturalistic images based on a very brief presentation (25 ms) of a few small visible image fragments. In the main experiment, we reduced the possibility to perform the task based on global- luminance positional cues by presenting randomly inverted-contrast images, and we measured how much observers’ performance relies on the local features contained in the fragments or on global information. The size and the number of fragments were determined in two preliminary experiments. Results show that observers are very skilled in fast image discrimination, even when a drastic occlusion is applied. When observers cannot rely on the position of global-luminance information, the probability of correct discrimination increases when the visible fragments contain a high number of optimal features. These results suggest that such optimal local information contributes to the successful reconstruction of naturalistic images even in challenging conditions. Serena Castellotti, Ottavia D’Agostino, & Maria Michela Del Viva https://www.pisavisionlab.org/2023/12/07/fast-discrimination-of-fragmentary-images-the-role-of-local-optimal-information/castellotti2023_patches/https://doi.org/10.3389/fnhum.2023.1049615 https://www.pisavisionlab.org/2023/12/07/time-estimation-during-motor-activity/ Thu, 07 Dec 2023 17:39:23 +0000 https://www.pisavisionlab.org/?p=4824 Front. Hum. Neurosci. 17:1134027 Several studies on time estimation showed that the estimation of temporal intervals is related to the amount of attention devoted to time. This is explained by the scalar timing theory, which assumes that attention alters the number of pulses transferred by our internal clock to an accumulator that keeps track of the elapsed time. In a previous study, it was found that time underestimation during cognitive-demanding tasks was more pronounced while walking than while sitting, whereas no clear motor-induced effects emerged without a concurrent cognitive task. What remains unclear then is the motor interference itself on time estimation. Here we aim to clarify how the estimation of time can be influenced by demanding motor mechanisms and how different motor activities interact with concurrent cognitive tasks during time estimation. To this purpose, we manipulated simultaneously the difficulty of the cognitive task (solving arithmetic operations) and the motor task. We used an automated body movement that should require no motor or mental effort, a more difficult movement that requires some motor control, and a highly demanding movement requiring motor coordination and attention. We compared the effects of these three types of walking on time estimation accuracy and uncertainty, arithmetic performance, and reaction times. Our findings confirm that time estimation is affected by the difficulty of the cognitive task whereas we did not find any evidence that time estimation changes with the complexity of our motor task, nor an interaction between walking and the concurrent cognitive tasks. We can conclude that walking, although highly demanding, does not have the same effects as other mental tasks on time estimation. Ottavia D’Agostino, Serena Castellotti, & Maria Michela Del Viva https://www.pisavisionlab.org/2023/12/07/time-estimation-during-motor-activity/dagostino2023_tapis2/ https://doi.org/10.3389/fnhum.2023.1134027 https://www.pisavisionlab.org/2023/12/07/psychophysiological-and-behavioral-responses-to-descriptive-labels-in-modern-art-museums/ Thu, 07 Dec 2023 17:44:40 +0000 https://www.pisavisionlab.org/?p=4828 PLoS One 18, e0284149 Educational tools in art exhibitions seem crucial to improve the cultural and aesthetic experi- ence, particularly of non-expert visitors, thus becoming a strategic goal for museums. How- ever, there has not been much research regarding the impact of labels on the quality of visitors’ aesthetic experience. Therefore, here we compared the impact on the cognitive and emotional experience of naïve visitors between essential and descriptive labels, through multiple objective and subjective measurements, focusing on the controversial modern art museum context. We found that, after detailed descriptions, observers spend more time inspecting artworks, their eyes wander more looking for the described elements, their skin conductance and pupil size increase, and overall, they find the content less complex and more arousing. Our findings show that people do receive important benefits from reading detailed information about artworks. This suggests that elaborating effective labels should be a primary goal for museums interested in attracting a non-expert public. Serena Castellotti, Ottavia D’Agostino, Angelica Mencarini, Martina Fabozzi, Raimondo Varano, Stefano Mastandrea, Irene Baldriga, & Maria Michela Del Viva https://www.pisavisionlab.org/2023/12/07/psychophysiological-and-behavioral-responses-to-descriptive-labels-in-modern-art-museums/castellotti2023_museo/https://doi.org/10.1371/journal.pone.0284149 https://www.pisavisionlab.org/2023/12/07/saccadic-trajectories-deviate-toward-or-away-from-optimally-informative-visual-features/ Thu, 07 Dec 2023 17:50:17 +0000 https://www.pisavisionlab.org/?p=4832 IScience, 107282 The saccades’ path is influenced by visual distractors, making their trajectory curve away or toward them. Previous research suggested that the more salient the distractor, the more pronounced is the curvature. We investigate the saliency of spatial visual features, predicted by a constrained maximum entropy model to be optimal or non-optimal information carriers in fast vision, by using them as distractors in a saccadic task. Their effect was compared to that of luminance- based control distractors. Optimal features evoke a larger saccadic curvature compared to non-optimal features, and the magnitude and direction of deviation change as a function of the delay between distractor and saccade onset. Effects were similar to those found with high-luminance versus low-luminance distrac- tors. Therefore, model-predicted information optimal features interfere with target-oriented saccades, following a dynamic attraction–repulsion pattern. This suggests that the visuo-oculomotor system rapidly and automatically processes optimally informative features while programming visually guided eye movements. Serena Castellotti, Martin Szinte, Maria Michela Del Viva, & Anna Montagnini https://www.pisavisionlab.org/2023/12/07/saccadic-trajectories-deviate-toward-or-away-from-optimally-informative-visual-features/castellotti2023_curvature/https://doi.org/https://doi.org/10.1016/j.isci.2023.107282 https://www.pisavisionlab.org/2023/12/07/the-italian-colour-lexicon-in-tuscany-elicited-lists-cognitive-salience-and-semantic-maps-of-colour-terms/ Thu, 07 Dec 2023 17:54:13 +0000 https://www.pisavisionlab.org/?p=4836 Humanities and Social Sciences Communications, 10(1), 900 We investigated the Tuscan Italian colour inventory, with the aim of establishing the cog- nitive salience of the basic colour terms (BCTs) and most frequent non-BCTs. Native speakers from Tuscany (N = 89) completed a colour-term elicitation task lasting for 5 min. In total, 337 unique terms were elicited, with an average list length of 30.06. The frequency of each term, its mean list position and cognitive salience index (S) were calculated. The CTs with the highest S (ranked 1–13) included 10 counterparts of the Berlin and Kay BCTs listed in their 1969 seminal work and three basic ‘blue’ terms, blu, azzurro, celeste, estimated for Tuscan respondents by Del Viva et al. in 2022. S-index and Zipf-function (the terms’ “popularity”) indicated that fucsia (rank 14) is conceivably an emerging BCT in (Tuscan) Italian. Other cognitively salient non-BCTs are lilla, magenta, ocra and beige. The terms’ 3D semantic map (conceptual closeness), assessed using multidimensional scaling and cluster analysis, revealed that in the lists, closely associated CTs were arranged along three com- peting criteria: the term’s salience gradient; word length; and clustering of fully chromatic concepts with those defined primarily by lightness or desaturation. We also consider salient Italian non-BCTs as indicators of the ongoing process of lexical refinement in certain areas of the colour space. In conclusion, measures of elicitation productivity, as well as the augmented BCT inventory, including the Tuscan ‘triple blues’, and abundant hyponyms and derived forms all indicate (Tuscan) Italian speakers’ “cultural competence” in the colour domain and the need to communicate nuanced information about colour shades. Maria Michela Del Viva, Serena Castellotti, & Galina V. Paramei https://www.pisavisionlab.org/2023/12/07/the-italian-colour-lexicon-in-tuscany-elicited-lists-cognitive-salience-and-semantic-maps-of-colour-terms/delviva2023_color/https://doi.org/10.1057/s41599-023-02393-4 https://www.pisavisionlab.org/2023/12/21/drivers-performance-assessment-approaching-pedestrian-crossings-through-the-analysis-of-the-speed-and-perceptive-data-recorded-during-on-field-tests/ Thu, 21 Dec 2023 11:49:47 +0000 https://www.pisavisionlab.org/?p=4845 Heliyon (in press) Pedestrian fatalities in road accidents represent one of the biggest causes of death in the world despite the great efforts that have been made to decrease the involvement of vulnerable road users in road accidents. Literature analysis revealed the presence of several studies aimed at investigating the phenomenon and proposing strategies to improve pedestrian safety, but this is still not enough to considerably reduce the number of pedestrians killed on the road. In this context, with the aim to take a step forward in the topic, this paper describes a naturalistic driving assessment carried out in Firenze aimed at evaluating the effect of different pedestrian crossing configurations on the drivers’ behavior, especially concerning the reduction of the speeding phenomenon approaching a pedestrian crossing. The experiment was conducted on a section of an urban collector road within the Firenze suburban area. Crucially, over the past few years, different traffic calming interventions have been implemented along this street. Among the different traffic calming countermeasures, both the presence of a traffic light and trapezoidal deflection have been considered to assess their effect on drivers’ behavior, also with reference to specific aspects related to the drivers’ perception. During the experiment, thirty-six users drove their own vehicles along the street, encountering different pedestrian crossing configurations. During the driving speed, deceleration and ocular fixation were recorded. This study shows the difference in drivers’ behavior in response to different traffic calming countermeasures. It demonstrates also that the raised pedestrian crossing caused a significant effect on reducing the speed approaching a pedestrian crossing. Moreover, it is observed that, when perceptive countermeasures are present, the drivers’ behavior changes only if the pedestrian crossing configuration is perceived in foveal vision; suggesting that the correct identification of the configuration is crucial to implement a congruent and safe driving behavior. Meocci, M., Terrosi, A., Paliotto, A., Arrighi, R. & Petrizzo, I. https://www.pisavisionlab.org/2024/10/04/weakened-sustained-attention-and-increased-cognitive-effort-after-total-sleep-deprivation-a-virtual-reality-ecological-study/ Fri, 04 Oct 2024 09:25:02 +0000 https://www.pisavisionlab.org/?p=4985 International Journal of Human–Computer Interaction, 39(18), 3546–3555 Total sleep deprivation (TSD) has a major impact on sustained attention as reported by previous studies that have investigated effects of TSD, however by using classical neuropsychological tests that lack ecological validity. To study the effects of TSD on daily-life activities, we carried out an ecological evaluation of sustained attention using a virtual reality task requiring driving along an unpredictable path. We enrolled 30 volunteers who underwent two experimental sessions: baseline (after normal sleep night) and after 36 h of total TSD. We assessed changes in sustained attentional performance by analysing the series of visuomotor adjustments while driving. After TSD, we found greater inaccuracy and longer attentional lapses. Furthermore, the visuomotor adjustments series exhibited higher long-range correlations (self-similarity) which has been associated with greater cognitive efforts. Sustained attention assessed by the ecological task requiring visuomotor coordination gets worse after 36 h of total TSD together with greater cognitive effort. Bufano, P., Albertini, N., Chiarelli, S., Barone, V., Valleggi, M., Parrini, G., … Menicucci, D. https://doi.org/10.1080/10447318.2022.2099047 https://www.pisavisionlab.org/2024/10/04/active-vision-shapes-ocular-dominance-4/ Fri, 04 Oct 2024 10:11:21 +0000 https://www.pisavisionlab.org/?p=4988 ["invited talk"] University of Washington 05/10/2023 08/10/2023 Paola Binda https://www.pisavisionlab.org/2024/10/04/pupillometric-signature-of-implicit-learning-2/ Fri, 04 Oct 2024 10:21:38 +0000 https://www.pisavisionlab.org/?p=4991 ["invited talk"] MySpace Workshop 14/04/2023 15/04/2023 Paola Binda

Genova

44.4071448 8.9347381 14 ChIJrZrU3FJB0xIRCmKBGPGEaiM Genoa Liguria GE Italy IT https://www.pisavisionlab.org/2026/09/10/quantum-spin-models-for-numerosity-perception/ Thu, 10 Sep 2026 08:14:22 +0000 https://www.pisavisionlab.org/?p=5425 PLOS ONE Humans share with animals, both vertebrates and invertebrates, the capacity to sense the number of items in their environment already at birth. The pervasiveness of this skill across the animal kingdom suggests that it should emerge in very simple populations of neurons. Current modelling literature, however, has struggled to provide a simple architecture carrying out this task, with most proposals suggesting the emergence of number sense in multi-layered complex neural networks, and typically requiring supervised learning; while simple accumulator models fail to predict Weber’s Law, a common trait of human and animal numerosity processing. We present a simple quantum spin model with all-to-all connectivity, where numerosity is encoded in the spectrum after stimulation with a number of transient signals occurring in a random or orderly temporal sequence. We use a paradigmatic simulational approach borrowed from the theory and methods of open quantum systems out of equilibrium, as a possible way to describe information processing in neural systems. Our method is able to capture many of the perceptual characteristics of numerosity in such systems. The frequency components of the magnetization spectra at harmonics of the system’s tunneling frequency increase with the number of stimuli presented. The amplitude decoding of each spectrum, performed with an ideal-observer model, reveals that the system follows Weber’s law. This contrasts with the well-known failure to reproduce Weber’s law with linear system or accumulators models. Yago Malo J, Cicchini GM, Morrone MC, Chiofalo ML https://www.pisavisionlab.org/2026/09/10/quantum-spin-models-for-numerosity-perception/journal-pone-0284610/https://doi.org/10.1371/journal.pone.0284610 https://www.pisavisionlab.org/2026/09/10/development-of-bold-response-to-motion-in-human-infants/ Thu, 10 Sep 2026 08:23:20 +0000 https://www.pisavisionlab.org/?p=5428 The Journal of Neuroscience Behavioral studies suggest that motion perception is rudimentary at birth and matures steadily over the first few years. We demonstrated previously that the major cortical associative areas serving motion processing, like middle temporal complex (MT+), visual cortex area 6 (V6), and PIVC in adults, show selective responses to coherent flow in 8-week-old infants. Here, we study the BOLD response to the same motion stimuli in 5-week-old infants (four females and four males) and compare the maturation between these two ages. The results show that MT+ and PIVC areas show a similar motion response at 5 and 8 weeks, whereas response in the V6 shows a reduced BOLD response to motion at 5 weeks, and cuneus associative areas are not identifiable at this young age. In infants and in adults, primary visual cortex (V1) does not show a selectivity for coherent motion but shows very fast development between 5 and 8 weeks of age in response to the appearance of motion stimuli. Resting-state correlations demonstrate adult-like functional connectivity between the motion-selective associative areas but not between primary cortex and temporo-occipital and posterior-insular cortices. The results are consistent with a differential developmental trajectory of motion area respect to other occipital regions, probably reflecting also a different development trajectory of the central and peripheral visual field. SIGNIFICANCE STATEMENT How the cortical visual areas attain the specialization that we observed in human adults in the first few months of life is unknown. However, this knowledge is crucial to understanding the consequence of perinatal brain damage and its outcome. Here, we show that motion selective areas are already functioning well in 5-week-old infants with greater responses for detecting coherent motion over random motion, suggesting that very little experience is needed to attain motion selectivity. Laura Biagi, Michela Tosetti, Sofia Allegra Crespi and Maria Concetta Morrone https://www.pisavisionlab.org/2026/09/10/development-of-bold-response-to-motion-in-human-infants/3825-full/https://doi.org/10.1523/JNEUROSCI.0837-22.2023 https://www.pisavisionlab.org/2026/09/10/the-duration-effect-of-short-term-monocular-deprivation-measured-by-binocular-rivalry-and-binocular-combination/ Thu, 10 Sep 2026 08:30:19 +0000 https://www.pisavisionlab.org/?p=5431 Vision Research The ocular dominance shift observed after short-term monocular deprivation is a widely used measure of visual homeostatic plasticity in adult humans. Binocular rivalry and binocular combination techniques are used interchangeably to characterize homeostatic plasticity, sometimes leading to contradictory results. Here we directly compare the effect of short-term monocular deprivation on ocular dominance measured by either binocular rivalry or binocular combination and its dependence on the duration of deprivation (15 or 120 min) in the same group of participants. Our results show that both binocular rivalry and binocular combination provide reliable estimates of ocular dominance, which are strongly correlated across techniques both before and after deprivation. Moreover, while 15 min of monocular deprivation induce a larger shift of ocular dominance when measured using binocular combination compared to binocular rivalry, for both techniques, the shift in ocular dominance exhibits a strong dependence on the duration of monocular deprivation, with longer deprivation inducing a larger and longer-lasting shift in ocular dominance. Taken together, our results indicate that both binocular rivalry and binocular combination offer very consistent and reliable measurements of both ocular dominance and the effect short-term monocular deprivation. Antoine Prosper, Martina Pasqualetti, Maria Concetta Morrone, Claudia Lunghi https://www.pisavisionlab.org/2026/09/10/the-duration-effect-of-short-term-monocular-deprivation-measured-by-binocular-rivalry-and-binocular-combination/1-s2-0-s0042698923001025-main/https://doi.org/10.1016/j.visres.2023.108278