Background: The use of Rhesus macaques in vision research is crucial due to their visual system's similarity to humans. While invasive techniques have been the norm, there has been a shift towards non-invasive methods, such as facemasks and head molds, to enhance animal welfare and address ethical concerns.
New Method: We present a non-invasive, 3D-printed chinrest with infrared sensors, adapted from canine research, allowing for accurate eye movement measurements and voluntary animal participation in experiments.
When a visual stimulus is repeated, average neuronal responses typically decrease, yet they might maintain or even increase their impact through increased synchronization. Previous work has found that many repetitions of a grating lead to increasing gamma-band synchronization. Here, we show in awake macaque area V1 that both repetition-related reductions in firing rate and increases in gamma are specific to the repeated stimulus.
View Article and Find Full Text PDFBrain perturbation studies allow detailed causal inferences of behavioral and neural processes. Because the combination of brain perturbation methods and neural measurement techniques is inherently challenging, research in humans has predominantly focused on non-invasive, indirect brain perturbations, or neurological lesion studies. Non-human primates have been indispensable as a neurobiological system that is highly similar to humans while simultaneously being more experimentally tractable, allowing visualization of the functional and structural impact of systematic brain perturbation.
View Article and Find Full Text PDFCurr Opin Physiol
August 2020
Vision rests on computations that primarily rely on the parvocellular and magnocellular geniculate relay of retinal signals to V1. Secondary pathways involving superior colliculus, koniocellular lateral geniculate nucleus and pulvinar and their V1-bypassing projections to higher order cortex are known to exist. While they may form an evolutionary old visual system, their contribution to perception and visually guided behaviour remain largely obscure.
View Article and Find Full Text PDFRecent research indicates that attentional stimulus selection could be a rhythmic process. In monkey, neurons in V4 and IT exhibit rhythmic spiking activity in the theta range in response to a stimulus. When two stimuli are presented together, the rhythmic neuronal responses to each occur in anti-phase, a result indicative of competitive interactions.
View Article and Find Full Text PDFNon-human primate neuroimaging is a rapidly growing area of research that promises to transform and scale translational and cross-species comparative neuroscience. Unfortunately, the technological and methodological advances of the past two decades have outpaced the accrual of data, which is particularly challenging given the relatively few centers that have the necessary facilities and capabilities. The PRIMatE Data Exchange (PRIME-DE) addresses this challenge by aggregating independently acquired non-human primate magnetic resonance imaging (MRI) datasets and openly sharing them via the International Neuroimaging Data-sharing Initiative (INDI).
View Article and Find Full Text PDFBackground: Neuroscientists commonly use permanently implanted headposts to stabilize the head of nonhuman primates (NHPs) during electrophysiology and functional magnetic resonance imaging (fMRI). Here, we present improved methodology for MRI-compatible implants without the use of acrylic for head stabilization in NHPs.
New Method: MRI is used to obtain a 3D-reconstruction of NHP skulls, which are used to create customized implants by modeling intersections with the bone.
Growing evidence suggests that distributed spatial attention may invoke theta (3-9 Hz) rhythmic sampling processes. The neuronal basis of such attentional sampling is, however, not fully understood. Here we show using array recordings in visual cortical area V4 of two awake macaques that presenting separate visual stimuli to the excitatory center and suppressive surround of neuronal receptive fields (RFs) elicits rhythmic multi-unit activity (MUA) at 3-6 Hz.
View Article and Find Full Text PDF