We tested the theory that depletion of noradrenaline reduces the plasticity of the visual cortex in kittens by using another method of depletion. Lesions were made in the lateral hypothalamus to interrupt fibers in the dorsal noradrenergic bundle going from the locus ceruleus to the telencephalon. The lesions were induced at approximately 3 1/2 weeks of age in kittens; approximately 2 weeks lat...

The primary visual cortex shows synaptic plasticity during a postnatal "critical period," and its plasticity declines with development. Indeed, we found a developmental decrease in the induction of long-term potentiation (LTP) in the rat visual cortex. In visual cortex slices obtained from 2- to 3-week-old rats, tetanic stimulation (100 Hz for 1 sec, twice at an interval of 30 sec) of the white...

Why is it hard to divide attention between dissimilar activities, such as reading and listening to a conversation? We used functional magnetic resonance imaging (fMRI) to study interference between simple auditory and visual decisions, independently of motor competition. Overlapping activity for auditory and visual tasks performed in isolation was found in lateral prefrontal regions, middle tem...

Orientation selectivity of neurons in the primary visual cortex is thought to be an important requisite for the preprocessing of visual information, which is followed by more complex information processing and representation in the extrastriate cortex for visual perception. It is widely accepted that neurons in the primary visual cortex optimally responding to similar stimulus orientations are ...

It remains unclear to what extent retinotopic maps can undergo large-scale plasticity following damage to human visual cortex. The literature has predominately focused on retinotopic changes in patients with retinal pathologies or congenital brain malformations. Yet, damage to the adult visual cortex itself is common in cases such as stroke, tumor, or trauma. To address this issue, we used a un...

OPEN ACCESS Figure 1 Frontal eye model in humans. A1 right hemifield of right visual field, A2 nasal retina of right eye, A3 visual cortex of left cerebral hemisphere, A4 motor cortex of left cerebral hemisphere, A5 right upper limb, B1 left hemifield of right visual field, B2 temporal retina of right eye, B3 visual cortex of right cerebral hemisphere, B4 motor cortex of right cerebral cortex, ...

OPEN ACCESS Figure 1 Frontal eye model in humans. A1 right hemifield of right visual field, A2 nasal retina of right eye, A3 visual cortex of left cerebral hemisphere, A4 motor cortex of left cerebral hemisphere, A5 right upper limb, B1 left hemifield of right visual field, B2 temporal retina of right eye, B3 visual cortex of right cerebral hemisphere, B4 motor cortex of right cerebral cortex, ...

measure retinotopic organization within human cortex is described. The method is based on a visual stimulus that creates a traveling wave of neural activity within retinotopically organized visual areas. We measured the fMRI signal caused by this stimulus in visual cortex and represented the results on images of the flattened cortical sheet. We used the method to locate visual areas and to eval...