Biology subjects

Hochmann, J.-R.

Publications and source records attributed to Hochmann, J.-R..

6 recordsLinked to original sources

bioRxiv2026

Acceleration of vision changes object representations from infancy to adulthood

While much of the neural and cognitive machinery for visual perception is in place within weeks from birth, we identified and quantified a fundamental difference between infant and adult vision: the temporal rate at which meaningful visual information can be reliably extracted. Using frequency-tagging electroencephalography with rapid serial visual presentation, we found that object categorization at 4 and 9 months is respectively seven times and two to three times slower than in adults. Using quantitative information from infants experiments, we created and presented accelerated visual streams to adults, to match infants perceptual experience. We used deep convolutional neural networks to identify object representations that match those elicited in adults when accelerating the information flow. Results show that acceleration compromises finer-grained object distinction while sparing broad, general object representations. We propose that slow vision is a design feature of early development for preserving and highlighting the most stable and general features of the world.

neuroscience↗

bioRxiv2026

Estimating the duration of perceptual moments from early infancy to adulthood

Although human perception appears continuous, converging evidence suggests that sensory input is integrated over discrete temporal windows. The duration of these Temporal Integration Windows (TIWs) determines the temporal resolution of perception, but how this fundamental property develops across infancy and childhood remains unknown. Here, we estimate TIW duration from 5 months of age to adulthood using a novel, instruction-free eye-tracking paradigm that isolates pre-attentive visual integration. Across four experiments with the same paradigm (N = 308 participants), we measured spontaneous detection of a visual target that emerges only when two alternating displays are integrated within a single perceptual window. We observed a striking developmental shortening of the TIW. In adults and 5-year-olds, integration succeeded at short interstimulus intervals (ISIs; 16-32 ms) but failed at longer intervals (83-116 ms), yielding an estimated TIW of [~]57 ms. At 3 years, the TIW extended to [~]100 ms. In infancy, integration remained robust at substantially longer ISIs, with estimates of [~]250 ms at 18 and 8 months, and [~]400 ms at 5 months. The steepest reduction occurred within the first year of life. These findings reveal an approximately sevenfold acceleration in the temporal resolution of visual perception from early infancy to adulthood. Progressive shortening of TIWs suggests that infants and adults integrate sensory information over fundamentally different temporal scales, with implications for perceptual organization, learning, and neurodevelopmental trajectories.

neuroscience↗

bioRxiv2026

Hard-to-beat animacy perception: EEG evidence of accurate animate-inanimate distinction for ambiguous objects

Human recognition of objects as animate or inanimate is fast and accurate. However, this task may be challenging for objects with animal-like properties (e.g., presence of eyes/face), albeit being inanimate (e.g., a cow-mug). Lookalike objects provide an opportunity to examine how visual perception resolves categorical ambiguities and whether it exhibits an intrinsic bias to see animacy. During electroencephalography (EEG), we presented healthy humans with images of objects at a regular, rapid frequency (6 Hz), where every five exemplars of a standard category (animate or inanimate), an exemplar of the other oddball category was shown (1.2 Hz). In some conditions, oddball-stimuli were replaced by lookalikes. Periodic visual stimulation should give rise to a distinctive EEG response at 6 Hz. Moreover, if the oddball category elicits a different neural response than the standard category, a distinct response should be observed at 1.2 Hz. This categorization response was found for animate-oddballs among inanimate objects, and vice versa. It was also found for lookalike-oddballs presented among animate or inanimate objects, but it was significantly higher in the first case, implying that lookalike objects were perceived as more similar to inanimate than animate objects. The degree of animal resemblance modulated the amplitude of neural response to lookalikes, without however changing the category boundary. These results--also replicated in an artificial model of human vision--demonstrate that animal resemblance of objects is registered in visual perception, but it does not alter the critical ability to distinguish between what is truly alive and what is not.

neuroscience↗

bioRxiv2025

Animate-inanimate object categorization from minimal visual information in the human brain, human behavior, and deep neural networks

The distinction between animate and inanimate things is a main organizing principle of information in perception and cognition. Yet, animacy, as a visual property, has so far eluded operationalization. Which visual features are necessary and sufficient to see animacy? At which level of the visual hierarchy does the animate-inanimate distinction emerge? Here, we show that the animate-inanimate distinction is preserved even among images of objects that are made unrecognizable and only retain low- and mid-level visual features of their natural version. In particular, in three experiments, healthy human adults saw rapid sequences of images (6 Hz) where every five exemplars of a category (i.e., animate), an exemplar of another category (i.e., inanimate) was shown (1.2 Hz). Using frequency-tagging electroencephalography (ftEEG), we found significant neural responses at 1.2 Hz, indicating rapid and automatic detection of the periodic categorical change. Moreover, such effect was found -although increasingly weaker- for impoverished stimulus-sets that retained only certain (high-, mid-or low-level) features of the original colorful images (i.e., grayscale, texform and phase-scrambled images), and even if the images were unrecognizable. Similar effects were found with two Deep Neural networks (DNNs) presented with the same stimulus-sets. In sum, reliable categorization effects for dramatically impoverished and unrecognizable images, in humans EEG and DNN data, demonstrate that animacy representation emerges early in the visual hierarchy and is remarkably resilient to the loss of visual information.

neuroscience↗

bioRxiv2021

Visual object categorization in infancy

Humans make sense of the world by organizing things into categories. When and how does this process begin? We investigated whether real-world object categories that spontaneously emerge in the first months of life match categorical representations of objects in the human visual cortex. Taking infants looking times as a measure of similarity, we defined a representational space where each object was defined in relation to others of the same or different categories. This space was compared with hypothesis-based and fMRI-based models of visual-object categorization in the adults visual cortex. Analyses across different age groups revealed an incremental process with two milestones. Between 4 and 10 months, visual exploration guided by saliency gives way to an organization according to the animate-inanimate distinction. Between 10 and 19 months, a category spurt leads towards a mature organization. We propose that these changes underlie the coupling between seeing and thinking in the developing mind.

neuroscience↗

bioRxiv2020

Spatial relations trigger visual binding of people

To navigate the social world, humans must represent social entities, and the relationships between those entities, starting with spatial relationships. Recent research suggests that two bodies are processed with particularly high efficiency in visual perception, when they are in a spatial positioning that cues interaction, i.e. close and face-to-face. Socially relevant spatial relations such as facingness may facilitate visual perception by triggering grouping of bodies into a new integrated percept, which would make the stimuli more visible and easier to process. We used electroencephalography and a frequency-tagging paradigm to measure a neural correlate of grouping (or visual binding), while female and male participants saw images of two bodies face-to-face or back-to-back. The two bodies in a dyad flickered at frequency F1 and F2, respectively, and appeared together at a third frequency Fd (dyad frequency). This stimulation should elicit a periodic neural response for each body at F1 and F2, and a third response at Fd, which would be larger for face-to-face (vs. back-to-back) bodies, if those stimuli yield additional integrative processing. Results showed that responses at F1 and F2 were higher for upright than for inverted bodies, demonstrating that our paradigm could capture neural activity associated with viewing bodies. Crucially, the response to dyads at Fd was larger for face-to-face (vs. back-to-back) dyads, suggesting integration mediated by grouping. We propose that spatial relations that recur in social interaction (i.e., facingness) promote binding of multiple bodies into a new representation. This mechanism can explain how the visual system contributes to integrating and transforming the representation of disconnected body-shapes into structured representations of social events.

neuroscience↗