Browsing by Subject "vision"

Now showing 1 - 7 of 7
  • Thumbnail Image
    ItemOpen Access
    A Probabilistic Approach to Receptive Field Mapping in the Frontal Eye Fields.
    (Frontiers in systems neuroscience, 2016-01) Mayo, J Patrick; Morrison, Robert M; Smith, Matthew A
    Studies of the neuronal mechanisms of perisaccadic vision often lack the resolution needed to determine important changes in receptive field (RF) structure. Such limited analytical power can lead to inaccurate descriptions of visuomotor processing. To address this issue, we developed a precise, probabilistic technique that uses a generalized linear model (GLM) for mapping the visual RFs of frontal eye field (FEF) neurons during stable fixation (Mayo et al., 2015). We previously found that full-field RF maps could be obtained using 1-8 dot stimuli presented at frame rates of 10-150 ms. FEF responses were generally robust to changes in the number of stimuli presented or the rate of presentation, which allowed us to visualize RFs over a range of spatial and temporal resolutions. Here, we compare the quality of RFs obtained over different stimulus and GLM parameters to facilitate future work on the detailed mapping of FEF RFs. We first evaluate the interactions between the number of stimuli presented per trial, the total number of trials, and the quality of RF mapping. Next, we vary the spatial resolution of our approach to illustrate the tradeoff between visualizing RF sub-structure and sampling at high resolutions. We then evaluate local smoothing as a possible correction for situations where under-sampling occurs. Finally, we provide a preliminary demonstration of the usefulness of a probabilistic approach for visualizing full-field perisaccadic RF shifts. Our results present a powerful, and perhaps necessary, framework for studying perisaccadic vision that is applicable to FEF and possibly other visuomotor regions of the brain.
  • Thumbnail Image
    ItemOpen Access
    Circuits for presaccadic visual remapping.
    (J Neurophysiol, 2016-12-01) Rao, HM; Mayo, JP; Sommer, MA
    Saccadic eye movements rapidly displace the image of the world that is projected onto the retinas. In anticipation of each saccade, many neurons in the visual system shift their receptive fields. This presaccadic change in visual sensitivity, known as remapping, was first documented in the parietal cortex and has been studied in many other brain regions. Remapping requires information about upcoming saccades via corollary discharge. Analyses of neurons in a corollary discharge pathway that targets the frontal eye field (FEF) suggest that remapping may be assembled in the FEF's local microcircuitry. Complementary data from reversible inactivation, neural recording, and modeling studies provide evidence that remapping contributes to transsaccadic continuity of action and perception. Multiple forms of remapping have been reported in the FEF and other brain areas, however, and questions remain about the reasons for these differences. In this review of recent progress, we identify three hypotheses that may help to guide further investigations into the structure and function of circuits for remapping.
  • Thumbnail Image
    ItemOpen Access
    Distribution of visual and saccade related information in the monkey inferior colliculus.
    (Frontiers in neural circuits, 2012-01) Bulkin, David A; Groh, Jennifer M
    The inferior colliculus (IC) is an essential stop early in the ascending auditory pathway. Though normally thought of as a predominantly auditory structure, recent work has uncovered a variety of non-auditory influences on firing rate in the IC. Here, we map the location within the IC of neurons that respond to the onset of a fixation-guiding visual stimulus. Visual/visuomotor associated activity was found throughout the IC (overall, 84 of 199 sites tested or 42%), but with a far reduced prevalence and strength along recording penetrations passing through the tonotopically organized region of the IC, putatively the central nucleus (11 of 42 sites tested, or 26%). These results suggest that visual information has only a weak effect on early auditory processing in core regions, but more strongly targets the modulatory shell regions of the IC.
  • Thumbnail Image
    ItemOpen Access
    Dynamics of visual receptive fields in the macaque frontal eye field.
    (J Neurophysiol, 2015-12) Mayo, J Patrick; DiTomasso, Amie R; Sommer, Marc A; Smith, Matthew A
    Neuronal receptive fields (RFs) provide the foundation for understanding systems-level sensory processing. In early visual areas, investigators have mapped RFs in detail using stochastic stimuli and sophisticated analytical approaches. Much less is known about RFs in prefrontal cortex. Visual stimuli used for mapping RFs in prefrontal cortex tend to cover a small range of spatial and temporal parameters, making it difficult to understand their role in visual processing. To address these shortcomings, we implemented a generalized linear model to measure the RFs of neurons in the macaque frontal eye field (FEF) in response to sparse, full-field stimuli. Our high-resolution, probabilistic approach tracked the evolution of RFs during passive fixation, and we validated our results against conventional measures. We found that FEF neurons exhibited a surprising level of sensitivity to stimuli presented as briefly as 10 ms or to multiple dots presented simultaneously, suggesting that FEF visual responses are more precise than previously appreciated. FEF RF spatial structures were largely maintained over time and between stimulus conditions. Our results demonstrate that the application of probabilistic RF mapping to FEF and similar association areas is an important tool for clarifying the neuronal mechanisms of cognition.
  • Thumbnail Image
    ItemOpen Access
    Sensorimotor Learning in a Computerized Athletic Training Battery.
    (J Mot Behav, 2016-09) Krasich, Kristina; Ramger, Ben; Holton, Laura; Wang, Lingling; Mitroff, Stephen R; Gregory Appelbaum, L
    Sensorimotor abilities are crucial for performance in athletic, military, and other occupational activities, and there is great interest in understanding learning in these skills. Here, behavioral performance was measured over three days as twenty-seven participants practiced multiple sessions on the Nike SPARQ Sensory Station (Nike, Inc., Beaverton, Oregon), a computerized visual and motor assessment battery. Wrist-worn actigraphy was recorded to monitor sleep-wake cycles. Significant learning was observed in tasks with high visuomotor control demands but not in tasks of visual sensitivity. Learning was primarily linear, with up to 60% improvement, but did not relate to sleep quality in this normal-sleeping population. These results demonstrate differences in the rate and capacity for learning across perceptual and motor domains, indicating potential targets for sensorimotor training interventions.
  • Thumbnail Image
    ItemOpen Access
    Temporal resolution of single photon responses in primate rod photoreceptors and limits imposed by cellular noise.
    (Journal of neurophysiology, 2018-11-28) Field, Greg D; Uzzell, Valerie; Chichilnisky, EJ; Rieke, Fred
    Sensory receptor noise corrupts sensory signals, contributing to imperfect perception and dictating central processing strategies. For example, noise in rod phototransduction limits our ability to detect light and minimizing the impact of this noise requires precisely tuned nonlinear processing by the retina. But detection sensitivity is only one aspect of night vision: prompt and accurate behavior also requires that rods reliably encode the timing of photon arrivals. We show here that the temporal resolution of responses of primate rods is much finer than the duration of the light response and identify the key limiting sources of transduction noise. We also find that the thermal activation rate of rhodopsin is lower than previous estimates, implying that other noise sources are more important than previously appreciated. A model of rod single-photon responses reveals that the limiting noise relevant for behavior depends critically on how rod signals are pooled by downstream neurons.
  • Thumbnail Image
    ItemOpen Access
    Visual and oculomotor abilities predict professional baseball batting performance
    (International Journal of Performance Analysis in Sport, 2020-07-03) Liu, S; Edmunds, FR; Burris, K; Appelbaum, LG
    © 2020, © 2020 Cardiff Metropolitan University. Scientists and practitioners have long debated about the specific visual skills needed to excel at hitting a pitched baseball. To advance this debate, we evaluated the relationship between pre-season visual and oculomotor evaluations and pitch-by-pitch season performance data from professional baseball batters. Eye tracking, visual-motor, and optometric evaluations collected during spring training 2018 were obtained from 71 professional baseball players. Pitch-level data from Trackman 3D Doppler radar were obtained from these players during the subsequent season and used to generate batting propensity scores for swinging at pitches out of the strike zone (O-Swing), swinging at pitches in the strike zone (Z-Swing), and swinging at, but missing pitches in the strike zone (Z-Miss). Nested regression models to tested which evaluation(s) best predicted standardised plate discipline scores as well as batters’ highest attained league levels during the season. Results indicated that visual evaluations relying on eye tracking (smooth pursuit accuracy and oculomotor processing speed) significantly predicted the highest attained league level andpropensity scores associated with O-Swing and Z-Swing, but not Z-Miss. These exploratory findings indicate that batters with superior visual and oculomotor abilities are more discerning at the plate. These results provide new information about the role of vision in baseball batting.