We present a case of right hemispheric dominance for sign language but left hemispheric dominance for reading, in a left-handed deaf patient with epilepsy and left mesial temporal sclerosis. Atypical language laterality for ASL was determined by preoperative fMRI, and congruent with ASL modified WADA testing. We conclude that reading and sign language can have crossed dominance and preoperative...

We present a simplified binocular neural network model of the primary visual cortex with separate ON/OFF-pathways and modifiable afferent as well as intracortical synaptic couplings. Random as well as natural image stimuli drive the weight adaptation which follows Hebbian learning rules stabilized with constant norm and constant sum constraints. The simulations consider the development of orien...

We investigated whether fluoxetine, a widely prescribed medication for treatment of depression, restores neuronal plasticity in the adult visual system of the rat. We found that chronic administration of fluoxetine reinstates ocular dominance plasticity in adulthood and promotes the recovery of visual functions in adult amblyopic animals, as tested electrophysiologically and behaviorally. These...

The subplate forms a transient circuit required for development of connections between the thalamus and the cerebral cortex. When subplate neurons are ablated, ocular dominance columns do not form in the visual cortex despite the robust presence of thalamic axons in layer 4. We show that subplate ablation also prevents formation of orientation columns. Visual responses are weak and poorly tuned...

Popular culture, from movies, advertising, to self-help books, is captivated by left-brain/rightbrain differences and how these might influence our personalities, moods, and capabilities. Considering the interest in understanding the scientific basis for lateralized neural functions, it is surprising that model systems have not played a more dominant role in research on brain asymmetry. The lon...

In young animals, monocular deprivation leads to an ocular dominance shift, whereas in adults after the critical period there is no such shift. Chondroitin sulphate proteoglycans (CSPGs) are components of the extracellular matrix (ECM) inhibitory for axonal sprouting. We tested whether the developmental maturation of the ECM is inhibitory for experience-dependent plasticity in the visual cortex...

We studied the properties of visual cortical and lateral geniculate neurons in 5 macaque monkeys raised with the vision of one eye blurred by daily instillation of atropine. This rearing reduced the degree of binocular interaction in striate cortical neurons and caused a modest shift in eye dominance away from the atropine-treated eye. It also led to a difference in the spatial properties of ne...

Two differential pairing procedures were applied in the primary visual cortex of anesthetized and paralyzed kittens and cats, to produce changes in ocular dominance and interocular orientation disparity (IOD) during the time of recording of a single neuron. A first experiment was devised to demonstrate plasticity in the balance of monocular responses. The visual activity of the cell was driven ...

Two experiments used eye tracking to examine how infant and adult observers distribute their eye gaze on videos of a mother producing infant- and adult-directed speech. Both groups showed greater attention to the eyes than to the nose and mouth, as well as an asymmetrical focus on the talker's right eye for infant-directed speech stimuli. Observers continued to look more at the talker's apparen...

It has long been appreciated that in the visual cortex, particularly within a postnatal critical period for experience-dependent plasticity, the closure of one eye results in a shift in the responsiveness of cortical cells toward the experienced eye. While the functional aspects of this ocular dominance shift have been studied for many decades, their cortical substrates and synaptic mechanisms ...