fMRI adaptation revisited.
Cortex 80:154 (2016)
Adaptation has been widely used in functional magnetic imaging (fMRI) studies to infer neuronal response properties in human cortex. fMRI adaptation has been criticized because of the complex relationship between fMRI adaptation effects and the multiple neuronal effects that could underlie them....
Multimodal optogenetic neural interfacing device fabricated by scalable optical fiber drawing technique.
Applied Optics 54(34):10068 (2015)
We present a novel approach to the design and manufacture of optrodes for use in the biomedical research field of optogenetic neural interfacing. Using recently developed optical fiber drawing techniques that involve co-drawing metal/polymer composite fiber, we have assembled and characterized a...
Local and Global Correlations between Neurons in the Middle Temporal Area of Primate Visual Cortex.
Cerebral Cortex 25(9):3182 (2015)
In humans and other primates, the analysis of visual motion includes populations of neurons in the middle-temporal (MT) area of visual cortex. Motion analysis will be constrained by the structure of neural correlations in these populations. Here, we use multi-electrode arrays to measure correlat...
Spatial precision of population activity in primate area MT.
Journal of Neurophysiology 114(2):869 (2015)
The middle temporal (MT) area is a cortical area integral to the "where" pathway of primate visual processing, signaling the movement and position of objects in the visual world. The receptive field of a single MT neuron is sensitive to the direction of object motion but is too large to signal p...
Emergence of complex wave patterns in primate cerebral cortex.
Journal of Neuroscience 35(11):4657 (2015)
Slow brain rhythms are attributed to near-simultaneous (synchronous) changes in activity in neuron populations in the brain. Because they are slow and widespread, synchronous rhythms have not been considered crucial for information processing in the waking state. Here we adapted methods from tur...
Moving sensory adaptation beyond suppressive effects in single neurons.
Current Biology 24(20):R1012 (2014)
How an object is perceived depends on the temporal context in which it is encountered. Sensory signals in the brain also depend on temporal context, a phenomenon often referred to as adaptation. Traditional descriptions of adaptation effects emphasize various forms of response fatigue in single ...
Integration and segregation of multiple motion signals by neurons in area MT of primate.
Journal of Neurophysiology 111(2):369 (2014)
We used multielectrode arrays to measure the response of populations of neurons in primate middle temporal area to the transparent motion of two superimposed dot fields moving in different directions. The shape of the population response was well predicted by the sum of the responses to the cons...
A simpler primate brain: the visual system of the marmoset monkey.
Frontiers in Neural Circuits 8:96 (2014)
Humans are diurnal primates with high visual acuity at the center of gaze. Although primates share many similarities in the organization of their visual centers with other mammals, and even other species of vertebrates, their visual pathways also show unique features, particularly with respect t...
Texture-dependent motion signals in primate middle temporal area.
Journal of Physiology 591(22):5671 (2013)
Neurons in the middle temporal (MT) area of primate cortex provide an important stage in the analysis of visual motion. For simple stimuli such as bars and plaids some neurons in area MT--pattern cells--seem to signal motion independent of contour orientation, but many neurons--component cells--...
Excitatory and inhibitory contributions to receptive fields of alpha-like retinal ganglion cells in mouse.
Journal of Neurophysiology 110(6):1426 (2013)
The ON and OFF pathways that emerge at the first synapse in the retina are generally thought to be streamed in parallel to higher visual areas, but recent work shows cross talk at the level of retinal ganglion cells. The ON pathway drives inhibitory inputs onto some OFF ganglion cells, such that...
Cortical-like receptive fields in the lateral geniculate nucleus of marmoset monkeys.
Journal of Neuroscience 33(16):6864 (2013)
Most neurons in primary visual cortex (V1) exhibit high selectivity for the orientation of visual stimuli. In contrast, neurons in the main thalamic input to V1, the lateral geniculate nucleus (LGN), are considered to be only weakly orientation selective. Here we characterize a sparse population...
Noise normalizes firing output of mouse lateral geniculate nucleus neurons.
PLoS ONE 8(2):e57961 (2013)
The output of individual neurons is dependent on both synaptic and intrinsic membrane properties. While it is clear that the response of an individual neuron can be facilitated or inhibited based on the summation of its constituent synaptic inputs, it is not clear whether subthreshold activity, ...
Colour and pattern selectivity of receptive fields in superior colliculus of marmoset monkeys.
Journal of Physiology 590(16):4061 (2012)
The main subcortical visual targets of retinal output neurones (ganglion cells) are the parvocellular and magnocellular layers of the dorsal lateral geniculate nucleus (LGN) in the thalamus. In addition, a small and heterogeneous collection of ganglion cell axons projects to the koniocellular la...
Visual motion integration by neurons in the middle temporal area of a New World monkey, the marmoset.
Journal of Physiology 589(Pt 23):5741 (2011)
The middle temporal area (MT/V5) is an anatomically distinct region of primate visual cortex that is specialized for the processing of image motion. It is generally thought that some neurons in area MT are capable of signalling the motion of complex patterns, but this has only been established i...
Phase sensitivities, excitatory summation fields, and silent suppressive receptive fields of single neurons in the parastriate cortex of the cat.
Journal of Neurophysiology 106(4):1688 (2011)
We have recorded single-neuron activity from cytoarchitectonic area 18 of anesthetized (0.4-0.7% isoflurane in 65% N₂O-35% O₂ gaseous mixture) domestic cats. Neurons were identified as simple or complex on the basis of the ratios between the phase-variant (F1) component and the mean firing rate ...
The impact of brief exposure to high contrast on the contrast response of neurons in primate lateral geniculate nucleus.
Journal of Neurophysiology 106(3):1310 (2011)
Prolonged exposure to an effective stimulus generally reduces the sensitivity of neurons early in the visual pathway. Yet eye and head movements bring about frequent changes in the retinal image, and it is less clear that exposure to brief presentations will produce similar desensitization. To a...
Slow intrinsic rhythm in the koniocellular visual pathway.
PNAS 108(35):14659 (2011)
Slow rhythmic changes in nerve-cell activity are characteristic of unconscious brain states and also may contribute to waking brain function by coordinating activity between cortical and subcortical structures. Here we show that slow rhythms are exhibited by the koniocellular (K) pathway, one of...
Information processing in the primate visual system.
Journal of Physiology 589(Pt 1):29 (2011)
Linear and nonlinear contributions to the visual sensitivity of neurons in primate lateral geniculate nucleus.
Journal of Neurophysiology 104(4):1884 (2010)
Several parallel pathways convey retinal signals to the visual cortex of primates. The signals of the parvocellular (P) and magnocellular (M) pathways are well characterized; the properties of other rarely encountered cell types are distinctive in many ways, but it is not clear that they can pro...
Combination of subcortical color channels in human visual cortex.
Journal of Vision 10(5):25 (2010)
Mechanisms of color vision in cortex have not been as well characterized as those in sub-cortical areas, particularly in humans. We used fMRI in conjunction with univariate and multivariate (pattern) analysis to test for the initial transformation of sub-cortical inputs by human visual cortex. S...