Biology subjects

Kupers, R.

Publications and source records attributed to Kupers, R..

3 recordsLinked to original sources

bioRxiv2026

Temporal dynamics of cognitive map formation in early- and late-onset blindness

Cognitive maps encode spatial relationships between locations and support flexible navigation. However, how these mental representations form in blindness remains unclear. Here, we introduce a multisensory virtual navigation paradigm that monitors non-visual cognitive map formation over time. Sixteen early blind (EB), 17 late blind (LB), and 29 sighted controls (SC) learned the layout of a tactile maze and, in a virtual version, repeatedly performed pointing (judgment of relative directions) and navigation (reaching locations) tasks. Thus, this experiment tracked both functional and spatio-cognitive components of cognitive map formation across multiple learning stages and showed that EB accumulated knowledge more slowly than SC. In addition, both EB and LB had reduced pointing accuracy under viewpoint changes, indicating difficulty translating cognitive maps into first-person perspectives. Yet, navigation and pointing improved in all groups, and a subset of EB and LB achieved expert-level performance. In sum, this study provides a scalable framework for tracking the temporal dimension of cognitive map formation in blindness and other neurological conditions, informing how spatial knowledge is acquired and translated into navigation behavior. Importantly, it suggests that allocentric cognitive map formation in blindness is an experience-dependent process that varies across time and individuals. Observed spatial disadvantages in both blind groups may result from adaptive strategies that constrain the use of allocentric cognitive maps, independent of prior visual experience.

neuroscience↗

bioRxiv2022

Brain morphometric changes in congenitally blind subjects: a 7 Tesla MRI study

We used ultra-high field (7 Tesla) magnetic resonance imaging (MRI) at submillimeter resolution to assess structural brain changes in congenitally blind (CB) compared to matched normal sighted control (SC) subject groups. Region-of-interest analysis revealed grey matter (GM) volumetric reductions in the CB group in left cuneus and occipital pole, right posterior collateral sulcus and right occipito-temporal medial lingual sulcus. Non-visual areas with GM reductions in CB included the left central, postcentral and superior frontal gyri, and the right subcallosal gyrus. In contrast, there were no significant group differences in cortical thickness when using stringent statistical criteria. Regional differences in white matter (WM) showed an overall pattern similar as that of GM changes, characterized by volume reductions in occipital, parietal and temporal areas, but with additional reductions in precuneus and medial orbitofrontal cortex. Differences in cortical curvature were mostly situated in the occipital cortex and bore a close relationship with areas showing GM alterations; they may be indicative of increased cortico-cortical connectivity of the visually-deprived occipital cortex. The CB group had GM reductions in the basal ganglia, i.e., caudate nucleus, putamen, nucleus accumbens, globus pallidus, and thalamus. Within the cerebellum, GM and WM volumes were also reduced in the CB. Segmentation of the thalamus, hippocampus and amygdala into anatomic divisions revealed GM reductions in a number of thalamic nuclei, a few hippocampal regions, but not within amygdala. There were no findings of increased volume or cortical thickness in the CB group. Together, these data reveal a multitude of GM and WM reductions in CB, comprising not only the occipital cortex, but also temporal, parietal, and prefrontal cortices, as well as the basal ganglia and cerebellum. These findings in the CB may seem at odds with the large literature showing that the visually-deprived occipital cortex becomes a multimodal cortex responding to diverse non-visual sensory and cognitive inputs. The seeming mismatch between morphological atrophy and enhanced multimodality of occipital areas combined with superior performance by the CB in various non-visual tasks poses a challenge for our understanding of brain plasticity.

neuroscience↗

bioRxiv2020

Cortical field potential dynamic driving human sensory, motor and cognitive functions

We lack viable explanations of how brain functions emerge from collective activities of neurons in networks. We recorded field potentials from many local networks in the human cerebral cortex during a wide variety of brain functions. The network dynamics showed that each local cortical network produced fluctuating attractor states. The state trajectories continuously stretched and contracted during all brain functions, leaving no stable patterns. Different local networks all produced this dynamic, despite different architectures. Single trial stimuli and tasks modified the stretching and contractions. These modified fluctuations cross-correlated among particular networks during specific brain functions. Spontaneous states, rest, sensory, motor and cognitive states all emerged from this dynamic. Its mathematical structure provides a general explanation of cortical dynamics that can be tested experimentally. This universal dynamic is a simple functional organizing principle for brain functions at the mm3 scale that is distinct from existing frameworks.

neuroscience↗