Publications - Neurobiology of Vision

  • Spatial clustering of orientation preference in primary visual cortex of the large rodent agouti. ISCIENCE

    Our results argue against V1 size as a key parameter in determining the presence of periodic orientation maps. They are consistent with a phylogenetic influence on the map layout and development, potentially reflecting distinct retinal traits or interspecies differences in cortical circuitry...
  • Orientation selectivity of neurons and their spatial layout in cat and agouti primary visual cortex.

    So far, there is no evidence of a columnar orientation preference map in rodent primary visual cortex, such as commonly observed in carnivores and primates. At the same time, orientation selective neurons have been found in all rodent species investigated, though interspersed....
  • The influence of interhemispheric connections on ongoing and evoked orientation preference maps and spiking activity

    In the primary visual cortex, neurons with similar physiological features are clustered together in columns extending through all six cortical layers. These columns form modular orientation preference maps.
  • Callosal Influence on Visual Receptive Fields Has an Ocular, an Orientation-and Direction Bias

    One leading hypothesis on the nature of visual callosal connections (CC) is that they replicate features of intrahemispheric lateral connections. However, CC act also in the central part of the binocular visual field.
  • Motion contrast in primary visual cortex: a direct comparison of single neuron and population encoding

    We analyzed firing rates and phase-locking to low-gamma frequency in single cells and neuronal assemblies. Motion contrast was reflected in all measures but in semi-independent populations.
  • Selective interhemispheric circuits account for a cardinal bias in spontaneous activity within early visual areas

    Ongoing brain activity exhibits patterns resembling neural ensembles co activated by stimulation or task performance.
  • Do lateral intrinsic and callosal axons have comparable actions in early visual areas ?

    By comparing data from lateral and feedback circuits, we conclude that visual callosal connections are more similar to intrinsic connections and can be interpreted as extending this circuit across the hemispheres.
  • Input and Output Gain Modulation by the Lateral Interhemispheric Network in Early Visual Cortex

    Neurons in the cerebral cortex are constantly integrating different types of inputs. Dependent on their origin, these inputs can be modulatory in many ways and, for example, change the neuron's responsiveness, sensitivity, or selectivity.
  • The influence of interhemispheric connections on spiking, assembly and LFP activities, and their phase relationship during figure-ground stimulation in primary visual cortex

    Desde os descobrimentos pioneiros de Hubel e Wiesel acumulou-se uma vasta literatura descrevendo as respostas neuronais do córtex visual primário (V1) a diferentes estímulos visuais. Estes estímulos consistem principalmente em barras em movimento, pontos ou grades, que são úteis para explorar as respostas dentro do...
  • An Updated Midline Rule: Visual Callosal Connections Anticipate Shape and Motion in Ongoing Activity across the Hemispheres

    If trajectory and direction of motion are known beforehand, the detection of a moving object at future positions might be facilitated. In agreement, primary visual cortical neurons close to the visual field's midline seem to anticipate movements and shapes of objects which...
  • The Visual Callosal Connection: A Connection Like Any Other?

    I propose that experimental results about the callosal circuit in early visual areas can be interpreted with respect to lateral connectivity in general.
  • Functional specificity of long-range intrinsic and interhemispheric connections in the visual cortex of strabismic cats.

  • The Perceptual Grouping Criterion of Colinearity is Reflected by Anisotropies of Connections in the Primary Visual Cortex.

  • The layout of orientation and ocular dominance domains in area 17 of strabismic cats.

  • Matching the modules: Cortical maps and long range intrinsic connections in cat visual cortex during development.

  • Feedback circuits: Link to ability to redirect attention.

  • Spatial analysis of ocular dominance patterns in monocularly deprived cats.

  • Two-dimensional analysis of the spacing of ocular dominance columns in normally raised and strabismic kittens.

  • The role of feedback in shaping neural representations in cat visual cortex.

  • Postnatal growth and column spacing in cat primary visual cortex.

  • Striatal activation during blepharospasm revealed by fMRI.

  • Precise placement of multiple electrodes into functionally predefined cortical locations.

  • Processing Deficits in Primary Visual Cortex of Amblyopic Cats.

  • Hemodynamic Signals Correlate Tightly with Synchronized Gamma Oscillations.

  • Pattern motion selectivity in population responses of area?18.

  • A Novel Interhemispheric Interaction: Modulation of Neuronal Cooperativity in the Visual Areas

  • Stimulus-Dependent Interaction between the Visual Areas 17 and 18 of the 2 Hemispheres of the Ferret (Mustela putorius).

  • Binocular phasic coactivation does not prevent ocular dominance segregation.

  • Specificity of Neuronal Responses in Primary Visual Cortex Is Modulated by Interhemispheric CorticoCortical Input.

  • A Linear Model of Phase-Dependent Power Correlations in Neuronal Oscillations

  • Pattern motion representation in primary visual cortex is mediated by transcortical feedback

    Global features of the visual scenery are fed back to lower visual processing units to facilitate the integration of local cues into a global construct.
  • Visual cortex combines a stimulus and an error-like signal with a proportion that is dependent on time, space, and stimulus contrast.

  • Multiplicative Mechanism of Lateral Interactions Revealed by Controlling Interhemispheric Input.