Receptive Field Properties Of Neurons Research Articles

Local field potentials, spiking activity, and receptive fields in human visual cortex.

The concept of receptive field (RF) is central to sensory neuroscience. Neuronal RF properties have been substantially studied in animals, while those in humans remain nearly unexplored. Here, we measured neuronal RFs with intracranial local field potentials (LFPs) and spiking activity in human visual cortex (V1/V2/V3). We recorded LFPs via macro-contacts and discovered that RF sizes estimated from low-frequency activity (LFA, 0.5-30 Hz) were larger than those estimated from low-gamma activity (LGA, 30-60 Hz) and high-gamma activity (HGA, 60-150 Hz). We then took a rare opportunity to record LFPs and spiking activity via microwires in V1 simultaneously. We found that RF sizes and temporal profiles measured from LGA and HGA closely matched those from spiking activity. In sum, this study reveals that spiking activity of neurons in human visual cortex could be well approximated by LGA and HGA in RF estimation and temporal profile measurement, implying the pivotal functions of LGA and HGA in early visual information processing.

Maximal Dependence Capturing as a Principle of Sensory Processing.

Sensory inputs conveying information about the environment are often noisy and incomplete, yet the brain can achieve remarkable consistency in recognizing objects. Presumably, transforming the varying input patterns into invariant object representations is pivotal for this cognitive robustness. In the classic hierarchical representation framework, early stages of sensory processing utilize independent components of environmental stimuli to ensure efficient information transmission. Representations in subsequent stages are based on increasingly complex receptive fields along a hierarchical network. This framework accurately captures the input structures; however, it is challenging to achieve invariance in representing different appearances of objects. Here we assess theoretical and experimental inconsistencies of the current framework. In its place, we propose that individual neurons encode objects by following the principle of maximal dependence capturing (MDC), which compels each neuron to capture the structural components that contain maximal information about specific objects. We implement the proposition in a computational framework incorporating dimension expansion and sparse coding, which achieves consistent representations of object identities under occlusion, corruption, or high noise conditions. The framework neither requires learning the corrupted forms nor comprises deep network layers. Moreover, it explains various receptive field properties of neurons. Thus, MDC provides a unifying principle for sensory processing.

Population receptive fields in nonhuman primates from whole-brain fMRI and large-scale neurophysiology in visual cortex.

Population receptive field (pRF) modeling is a popular fMRI method to map the retinotopic organization of the human brain. While fMRI-based pRF maps are qualitatively similar to invasively recorded single-cell receptive fields in animals, it remains unclear what neuronal signal they represent. We addressed this question in awake nonhuman primates comparing whole-brain fMRI and large-scale neurophysiological recordings in areas V1 and V4 of the visual cortex. We examined the fits of several pRF models based on the fMRI blood-oxygen-level-dependent (BOLD) signal, multi-unit spiking activity (MUA), and local field potential (LFP) power in different frequency bands. We found that pRFs derived from BOLD-fMRI were most similar to MUA-pRFs in V1 and V4, while pRFs based on LFP gamma power also gave a good approximation. fMRI-based pRFs thus reliably reflect neuronal receptive field properties in the primate brain. In addition to our results in V1 and V4, the whole-brain fMRI measurements revealed retinotopic tuning in many other cortical and subcortical areas with a consistent increase in pRF size with increasing eccentricity, as well as a retinotopically specific deactivation of default mode network nodes similar to previous observations in humans.

Stream-specific feedback inputs to the primate primary visual cortex

The sensory neocortex consists of hierarchically-organized areas reciprocally connected via feedforward and feedback circuits. Feedforward connections shape the receptive field properties of neurons in higher areas within parallel streams specialized in processing specific stimulus attributes. Feedback connections have been implicated in top-down modulations, such as attention, prediction and sensory context. However, their computational role remains unknown, partly because we lack knowledge about rules of feedback connectivity to constrain models of feedback function. For example, it is unknown whether feedback connections maintain stream-specific segregation, or integrate information across parallel streams. Using viral-mediated labeling of feedback connections arising from specific cytochrome-oxidase stripes of macaque visual area V2, here we show that feedback to the primary visual cortex (V1) is organized into parallel streams resembling the reciprocal feedforward pathways. This suggests that functionally-specialized V2 feedback channels modulate V1 responses to specific stimulus attributes, an organizational principle potentially extending to feedback pathways in other sensory systems.

The Life of a Trailing Spouse.

In 1981, I published a paper in the first issue of the Journal of Neuroscience with my postdoctoral mentor, Alan Pearlman. It reported a quantitative analysis of the receptive field properties of neurons in reeler mouse visual cortex and the surprising conclusion that although the neuronal somas were strikingly malpositioned, their receptive fields were unchanged. This suggested that in mouse cortex at least, neuronal circuits have very robust systems in place to ensure the proper formation of connections. This had the unintended consequence of transforming me from an electrophysiologist into a cellular and molecular neuroscientist who studied cell adhesion molecules and the molecular mechanisms they use to regulate axon growth. It took me a surprisingly long time to appreciate that your science is driven by the people around you and by the technologies that are locally available. As a professional puzzler, I like all different kinds of puzzles, but the most fun puzzles involve playing with other puzzlers. This is my story of learning how to find like-minded puzzlers to solve riddles about axon growth and regeneration.

Superior Colliculus: A Vision for Orienting

The superior colliculus contains neurons sensitive to motion direction. New research shows that these neurons are anatomically clustered: those representing the region of visual space 'seen' by both eyes preferentially respond to nasal motion directions and others to opposite directions.

Retinotopic Separation of Nasal and Temporal Motion Selectivity in the Mouse Superior Colliculus

Sensory neurons often display an ordered spatial arrangement that enhances the encoding of specific features on different sides of natural borders in the visual field (for example, [1-3]). In central visual areas, one prominent natural border is formed by the confluence of information from the two eyes, the monocular-binocular border [4]. Here, we investigate whether receptive field properties of neurons in the mouse superior colliculus show any systematic organization about the monocular-binocular border. The superior colliculus is a layered midbrain structure that plays a significant role in the orienting responses of the eye, head, and body [5]. Its superficial layers receive direct input from the majority of retinal ganglion cells and are retinotopically organized [6, 7]. Using two-photon calcium imaging, we recorded the activity of collicular neurons from the superficial layers of awake mice and determined their direction selectivity, orientation selectivity, and retinotopic location. This revealed that nearby direction-selective neurons have a strong tendency to prefer the same motion direction. In retinotopic space, the local preference of direction-selective neurons shows a sharp transition in the preference for nasal versus temporal motion at the monocular-binocular border. The maps representing orientation and direction appear to be independent. These results illustrate the important coherence between the spatial organization of inputs and response properties within the visual system and suggest a re-analysis of the receptive field organization within the superior colliculus from an ecological perspective.

A Role for Auditory Corticothalamic Feedback in the Perception of Complex Sounds.

Feedback signals from the primary auditory cortex (A1) can shape the receptive field properties of neurons in the ventral division of the medial geniculate body (MGBv). However, the behavioral significance of corticothalamic modulation is unknown. The aim of this study was to elucidate the role of this descending pathway in the perception of complex sounds. We tested the ability of adult female ferrets to detect the presence of a mistuned harmonic in a complex tone using a positive conditioned go/no-go behavioral paradigm before and after the input from layer VI in A1 to MGBv was bilaterally and selectively eliminated using chromophore-targeted laser photolysis. MGBv neurons were identified by their short latencies and sharp tuning curves. They responded robustly to harmonic complex tones and exhibited an increase in firing rate and temporal pattern changes when one frequency component in the complex tone was mistuned. Injections of fluorescent microbeads conjugated with a light-sensitive chromophore were made in MGBv, and, following retrograde transport to the cortical cell bodies, apoptosis was induced by infrared laser illumination of A1. This resulted in a selective loss of ∼60% of layer VI A1-MGBv neurons. After the lesion, mistuning detection was impaired, as indicated by decreased d′ values, a shift of the psychometric curves toward higher mistuning values, and increased thresholds, whereas discrimination performance was unaffected when level cues were also available. Our results suggest that A1-MGBv corticothalamic feedback contributes to the detection of harmonicity, one of the most important grouping cues in the perception of complex sounds.SIGNIFICANCE STATEMENT Perception of a complex auditory scene is based on the ability of the brain to group those sound components that belong to the same source and to segregate them from those belonging to different sources. Because two people talking simultaneously may differ in their voice pitch, perceiving the harmonic structure of sounds is very important for auditory scene analysis. Here we demonstrate mistuning sensitivity in the thalamus and that feedback from the primary auditory cortex is required for the normal ability of ferrets to detect a mistuned harmonic within a complex sound. These results provide novel insight into the function of descending sensory pathways in the brain and suggest that this corticothalamic circuit plays an important role in scene analysis.

Visual Stimulus Speed Does Not Influence the Rapid Emergence of Direction Selectivity in Ferret Visual Cortex

Sensory experience is necessary for the development of some receptive field properties of neurons in primary sensory cortical areas. However, it remains unclear whether the parameters of an individual animal's experience play an instructive role and influence the tuning parameters of cortical sensory neurons as selectivity emerges, or rather whether experience merely permits the completion of processes that are fully seeded at the onset of experience. Here we have examined whether the speed of visual stimuli that are presented to visually naive ferrets can influence the parameters of speed tuning and direction selectivity in cortical neurons. Visual experience is necessary for the development of direction selectivity in carnivores. If, during development, cortical neurons had the flexibility to choose from among different inputs with a range of spatial positions and temporal delays, then correlation-based plasticity mechanisms could instruct the precise spatiotemporal selectivity that underlies speed tuning and direction selectivity, and the parameters of an individual animal's experience would influence the tuning that emerges. Alternatively, the tuning parameters of these neurons may already be established at the onset of visual experience, and experience may merely permit the expression of this tuning. We found that providing different groups of animals with either slow (12.5 deg/s) or fast (50 deg/s) visual stimuli resulted in emergence of direction selectivity, but that speed tuning and direction selectivity were similar in the two groups. These results are more consistent with a permissive role for experience in the development of direction selectivity.SIGNIFICANCE STATEMENT The proper development of brain circuits and neural response properties depends on both nature (factors independent of experience) and nurture (factors dependent on experience). In this study, we examined whether the quality of visual experience of an individual animal influences the development of basic sensory detectors in primary visual cortex. We found that, although visual experience is required for the development of direction selectivity, tuning for stimulus speed could not be altered by specific experience with slow or fast stimuli. These results suggest that the tuning parameters for direction selectivity are specified independently of an animal's sensory experience, and that a range of experiences can promote the proper mature expression of direction selectivity in primary visual cortex.

Visual Receptive Field Properties of Neurons in the Mouse Lateral Geniculate Nucleus.

The lateral geniculate nucleus (LGN) is increasingly regarded as a “smart-gating” operator for processing visual information. Therefore, characterizing the response properties of LGN neurons will enable us to better understand how neurons encode and transfer visual signals. Efforts have been devoted to study its anatomical and functional features, and recent advances have highlighted the existence in rodents of complex features such as direction/orientation selectivity. However, unlike well-researched higher-order mammals such as primates, the full array of response characteristics vis-à-vis its morphological features have remained relatively unexplored in the mouse LGN. To address the issue, we recorded from mouse LGN neurons using multisite-electrode-arrays (MEAs) and analysed their discharge patterns in relation to their location under a series of visual stimulation paradigms. Several response properties paralleled results from earlier studies in the field and these include centre-surround organization, size of receptive field, spontaneous firing rate and linearity of spatial summation. However, our results also revealed “high-pass” and “low-pass” features in the temporal frequency tuning of some cells, and greater average contrast gain than reported by earlier studies. In addition, a small proportion of cells had direction/orientation selectivity. Both “high-pass” and “low-pass” cells, as well as direction and orientation selective cells, were found only in small numbers, supporting the notion that these properties emerge in the cortex. ON- and OFF-cells showed distinct contrast sensitivity and temporal frequency tuning properties, suggesting parallel projections from the retina. Incorporating a novel histological technique, we created a 3-D LGN volume model explicitly capturing the morphological features of mouse LGN and localising individual cells into anterior/middle/posterior LGN. Based on this categorization, we show that the ON/OFF, DS/OS and linear response properties are not regionally restricted. Our study confirms earlier findings of spatial pattern selectivity in the LGN, and builds on it to demonstrate that relatively elaborate features are computed early in the visual pathway.

Active Object Recognition with a Space-Variant Retina

When independent component analysis (ICA) is applied to color natural images, the representation it learns has spatiochromatic properties similar to the responses of neurons in primary visual cortex. Existing models of ICA have only been applied to pixel patches. This does not take into account the space-variant nature of human vision. To address this, we use the space-variant log-polar transformation to acquire samples from color natural images, and then we apply ICA to the acquired samples. We analyze the spatiochromatic properties of the learned ICA filters. Qualitatively, the model matches the receptive field properties of neurons in primary visual cortex, including exhibiting the same opponent-color structure and a higher density of receptive fields in the foveal region compared to the periphery. We also adopt the “self-taught learning” paradigm from machine learning to assess the model’s efficacy at active object and face classification, and the model is competitive with the best approaches in computer vision.

Linking structure and function: Development of lateral spatial interactions in macaque monkeys

Lateral spatial interactions among elements of a scene, which either enhance or degrade visual performance, are ubiquitous in vision. The neural mechanisms underlying lateral spatial interactions are a matter of debate, and various hypotheses have been proposed. Suppressive effects may be due to local inhibitory interactions, whereas facilitatory effects are typically ascribed either to the function of long-range horizontal projections in V1 or to uncertainty reduction. We investigated the development of lateral spatial interactions, facilitation and suppression, and compared their developmental profiles to those of potential underlying mechanisms in the visual system of infant macaques. Animals ranging in age from 10 weeks to 3 years were tested with a lateral masking paradigm. We found that suppressive interactions are present from very early in postnatal life, showing no change over the age range tested. However, facilitation develops slowly over the first year after birth. Our data suggest that the early maturation of suppressive interactions is related to the relatively mature receptive field properties of neurons in early visual cortical areas near birth in infant macaques, whereas the later maturation of facilitation is unlikely to be explained by development of local or long-range connectivity in primary visual cortex. Instead our data favor a late developing feedback or top-down cognitive process to explain the origin of facilitation.

Replicating Receptive Fields of Simple and Complex Cells in Primary Visual Cortex in a Neuronal Network Model with Temporal and Population Sparseness and Reliability

We propose a new principle for replicating receptive field properties of neurons in the primary visual cortex. We derive a learning rule for a feedforward network, which maintains a low firing rate for the output neurons (resulting in temporal sparseness) and allows only a small subset of the neurons in the network to fire at any given time (resulting in population sparseness). Our learning rule also sets the firing rates of the output neurons at each time step to near-maximum or near-minimum levels, resulting in neuronal reliability. The learning rule is simple enough to be written in spatially and temporally local forms. After the learning stage is performed using input image patches of natural scenes, output neurons in the model network are found to exhibit simple-cell-like receptive field properties. When the output of these simple-cell-like neurons are input to another model layer using the same learning rule, the second-layer output neurons after learning become less sensitive to the phase of gratings than the simple-cell-like input neurons. In particular, some of the second-layer output neurons become completely phase invariant, owing to the convergence of the connections from first-layer neurons with similar orientation selectivity to second-layer neurons in the model network. We examine the parameter dependencies of the receptive field properties of the model neurons after learning and discuss their biological implications. We also show that the localized learning rule is consistent with experimental results concerning neuronal plasticity and can replicate the receptive fields of simple and complex cells.

David Hubel and Torsten Wiesel

While attending medical school at McGill, David Hubel developed an interest in the nervous system during the summers he spent at the Montreal Neurological Institute. After heading to the United States in 1954 for a Neurology year at Johns Hopkins, he was drafted by the army and was assigned to the Neuropsychiatry Division at the Walter Reed Hospital, where he began his career in research and did his first recordings from the visual cortex of sleeping and awake cats. In 1958, he moved to the lab of Stephen Kuffler at Johns Hopkins, where he began a long and fruitful collaboration with Torsten Wiesel. Born in Sweden, Torsten Wiesel began his scientific career at the Karolinska Institute, where he received his medical degree in 1954. After spending a year in Carl Gustaf Bernhard's laboratory doing basic neurophysiological research, he moved to the United States to be a postdoctoral fellow with Stephen Kuffler. It was at Johns Hopkins where he met David Hubel in 1958, and they began working together on exploring the receptive field properties of neurons in the visual cortex. Their collaboration continued until the late seventies. Hubel and Wiesel's work provided fundamental insight into information processing in the visual system and laid the foundation for the field of visual neuroscience. They have had many achievements, including--but not limited to--the discovery of orientation selectivity in visual cortex neurons and the characterization of the columnar organization of visual cortex through their discovery of orientation columns and ocular-dominance columns. Their work earned them the Nobel Prize for Physiology or Medicine in 1981, which they shared with Roger Sperry.

Development of spatiotemporal frequency turning in rat lateral geniculate neuron

Background Recent researches suggested that properties of neurons in the lateral geniculate neuron (LGN) may represent an important neural limitation on the development of basic spatial and temporal vision,and even binocular rivalry.However,previous studies on the properties of spatiotemporal frequency tuning of LGN were rather concentrated on a monkey or cat,whereas little is known about rat. Objective This study was to examine the development of spatiotemporal frequency tuning in rats LGN. Methods Twenty Wistar rats were collected and divided into 14-16 day,20-22 day,27-30 day and 60 day groups according to the different ages after their eyes opened and 5 rats were assigned for each group.Extracellular single neuron recording was carried out in the rats to study the spatio-temporal receptive field properties of neurons in LGN by sinusoidal gratings visual stimuli.Dynamic changes of the spatio-temporal receptive field properties of neurons in LGN with the development of Wistar rats were evaluated. Results The differences between band-pass and low-pass distribution of temporal frequency or spatial frequency of rat LGN were not statistically significant (x2 =0.68,0.47,P＞0.05 ).The optimal temporal frequency of receptive field in rat LGN went up to the maximum value until 60 day in Wistar rats.The mean optimal temporal frequencies of neurons in the four different age groups were ( 2.5 ± 1.3 ),( 2.6± 1.2),(2.6± 1.1 ) and ( 3.6± 1.1 ) Hz with significant differences among the 4 groups (F=4.53,P＜0.05 ),and those in the 14-16 day group,20-22 day group,27- 30 day group were significantly lower than in the 60 days group ( q =4.43,4.10,4.03,P ＜ 0.05 ).No significant differences were seen among the 14-16 day group,20-22 day group and 27-30 day group ( P＞0.05 ).The optimal spatial frequency values in the four groups were ( 0.04 ± 0.04 ),( 0.04 ± 0.03 ),( 0.05 ± 0.03 ),( 0.05 ± 0.04 ) cpd,respectively without statistical difference among them ( F =0.58,P ＞ 0.05 ).The temporal and spatial bandwidth values in the various age groups were not statistically significant among the four groups ( F =0.37,1.22,P＞0.05). Conclusions The development of temporal and spatial frequency characteristics of the rat LGN receptive field may be related to its functional visual pathway. Key words: Lateral geniculate neuron; Spatiotemporal frequency tuning; Temporal frequency; Spatial frequency; Receptive field

Spatial coding and receptive field properties of neurons in the electrosensory lateral line lobe of Gnathonemus petersii stimulated by real objects

Event Abstract Back to Event Spatial coding and receptive field properties of neurons in the electrosensory lateral line lobe of Gnathonemus petersii stimulated by real objects Simone Gertz1, Jacob Engelmann2 and Gerhard Von Der Emde1* 1 University of Bonn, Zoology, Germany 2 University of Bielefeld, Germany The weakly electric fish Gnathonemus petersii explores its environment by active electrolocation, during which they emit electric signals and perceive the resulting electrical field with epidermal electroreceptors. Objects within the electric field project “electric images” onto the sensory surface of the fish. Analyzing these images enables the fish to discriminate between different object parameters, like material. This is an impressive ability, which has been extensively studied in behavioural experiments. The focus of the present study is to understand this capability at the neuronal level, i.e. to find out how information about objects is processed in the first central stage of the ascending electrosensory pathway, the electrosensory lateral line lobe (ELL). Thus, we relate the sensory input (= electric image of objects) to the neuronal response. We recorded extracellularly from single neurons in the ELL while presenting either a plastic or a metal cube (8mm³) within their receptive field (RF). The response of the neuron was analyzed for the parameters discharge rate, first spike latency and the consistency of the PSTH pattern. Further we used Receiver-Operating characteristic (ROC)-analysis to compare the quality of either coding strategy. The RF organization was analyzed with respect to the two cell classes found in the ELL, I(inhibitory)- and E(excitatory)-cells. We recorded neurons with RFs in all body regions, Schnauzenorgan, head and trunk, so the location was also included in the analysis. We propose that at the level of the ELL, both spike rate and first spike latency are used for coding, either separately or as mixed coding. Within the amplitude range investigated, we found linear encoding for both materials tested. There were neither significantly differences in RF size between the two cell classes nor in the different body regions, but the structural organization increases in complexity from rostral to caudal. However, our data indicates poor spatial resolution at the single cell level, thus the spatial sensitivity needed to completely process the electric image of an object can only be achieved by population coding upstream of the ELL. Keywords: active electrolocation, electric image, ELL, first spike latency, Neural coding, spike rate, weakly electric fish Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster Presentation (see alternatives below as well) Topic: Sensory: Electrosensory Citation: Gertz S, Engelmann J and Von Der Emde G (2012). Spatial coding and receptive field properties of neurons in the electrosensory lateral line lobe of Gnathonemus petersii stimulated by real objects. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00237 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 Apr 2012; Published Online: 07 Jul 2012. * Correspondence: Dr. Gerhard Von Der Emde, University of Bonn, Zoology, Bonn, 53115, Germany, vonderemde@uni-bonn.de Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Simone Gertz Jacob Engelmann Gerhard Von Der Emde Google Simone Gertz Jacob Engelmann Gerhard Von Der Emde Google Scholar Simone Gertz Jacob Engelmann Gerhard Von Der Emde PubMed Simone Gertz Jacob Engelmann Gerhard Von Der Emde Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Functional Specialization of Seven Mouse Visual Cortical Areas

To establish the mouse as a genetically tractable model for high-order visual processing, we characterized fine-scale retinotopic organization of visual cortex and determined functional specialization of layer 2/3 neuronal populations in seven retinotopically identified areas. Each area contains a distinct visuotopic representation and encodes a unique combination of spatiotemporal features. Areas LM, AL, RL, and AM prefer up to three times faster temporal frequencies and significantly lower spatial frequencies than V1, while V1 and PM prefer high spatial and low temporal frequencies. LI prefers both high spatial and temporal frequencies. All extrastriate areas except LI increase orientation selectivity compared to V1, and three areas are significantly more direction selective (AL, RL, and AM). Specific combinations of spatiotemporal representations further distinguish areas. These results reveal that mouse higher visual areas are functionally distinct, and separate groups of areas may be specialized for motion-related versus pattern-related computations, perhaps forming pathways analogous to dorsal and ventral streams in other species.

Population receptive fields in human visual cortex measured with subdural electrodes

PURPOSE. Electrophysiological methods in animal models have been used to identify receptive field properties of neurons within retinotopic maps. More recently functional magnetic resonance imaging (fMRI) methods in human have been used to estimate population receptive fields (pRF) (Dumoulin and Wandell, 2008; Kay et al., 2008). Following Yoshor et al. (2007), we developed an efficient method of electrocorticography (ECoG) using subdural electrodes in pre-surgical clinical subjects to estimate pRFs in human visual cortex. These measures bridge human fMRI and animal electrophysiological studies. METHODS. Two patients with implanted intracranial electrodes (2-mm surface diameter) viewed a flickering contrast pattern through a bar aperture that swept across the visual field 8 times (4 cardinal, 4 diagonal directions; 96 seconds total). The contrast pattern flickered at 7.5 Hz, creating a steady-state ECoG response with power concentrated at twice the stimulus frequency (15 Hz). For each electrode a time-series of the time-varying 15-Hz amplitude was extracted, and modeled using an isotropic 2D-Gaussian pRF. RESULTS. The pRF model fit occipital electrodes' time-series well, explaining up to 83% of the variance. The pRF parameters were similar to those obtained from fMRI; for example, the pRF size increased with eccentricity and was larger in extrastriate regions than in electrodes near the occipital pole. The signal response latencies were estimated from the phase of the response to full-field flicker (separate runs). We observed robust position-dependent latency effects, ranging from 10–40 ms delay relative to responses near the occipital pole. CONCLUSION. Population receptive fields can be estimated using ECoG. There is good agreement between fMRI and ECoG measures despite significant differences in their physiological bases. The ECoG data provide latency information that is unavailable in the fMRI responses. This is a valuable method for probing population-level spatiotemporal properties of receptive fields in human visual cortex.

Layer dependent visual receptive field properties in ferret superior colliculus

Event Abstract Back to Event Layer dependent visual receptive field properties in ferret superior colliculus Iain Stitt1*, Edgar Galindo-Leon1, Florian Pieper1, Gerhard Engler1 and Andreas Engel1 1 Institute for Neurophysiology and Pathophysiology, Universitätsklinikum Hamburg-Eppendorf, Germany The mammalian superior colliculus (SC) is a highly conserved midbrain structure that responds to novel external events and initiates orienting movements. Interestingly, all layers of the SC, regardless of modality, are organised into juxtaposed, overlaid maps of space. Recent anatomical studies have provided evidence for a direct superficial-to-deep projection in the SC. However, it remains unclear how much information is conveyed by this connectivity. Here, we recorded single and multi-unit activity, along with local field potentials from both superficial and deep layers of the SC with a dual-shank silicon multichannel probe. Spatial receptive fields of the neurons were determined using small (~3°) drifting gratings presented at 20x20 different locations on a rear projection screen. The location of spatial receptive fields recorded within individual SC penetrations were very similar, as predicted by anatomical connectivity. To assess directional/orientation tuning characteristics across SC layers, full field drifting gratings were presented with 8 directions spaced equally over 360 degrees. Of visually responsive units, 22% were classified as orienatation selective, 7% of were classified as direction selective, and 5% units displayed characteristics that were intermediate to both classifications. Correlation in feature selectivity between recording sites was greatest at neighbouring electrodes, and decreased proportionally with distance between recording sites. Previous studies have focused on the visual receptive field properties of neurons in the superficial, retinorecipient layers of the SC. In this study, we record from the entire laminar structure of the SC to assess the physiological relevance of the anatomically defined superficial-to-deep projection. Keywords: Perception, superior colliculus Conference: XI International Conference on Cognitive Neuroscience (ICON XI), Palma, Mallorca, Spain, 25 Sep - 29 Sep, 2011. Presentation Type: Poster Presentation Topic: Poster Sessions: Neurophysiology of Sensation and Perception Citation: Stitt I, Galindo-Leon E, Pieper F, Engler G and Engel A (2011). Layer dependent visual receptive field properties in ferret superior colliculus. Conference Abstract: XI International Conference on Cognitive Neuroscience (ICON XI). doi: 10.3389/conf.fnhum.2011.207.00361 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 23 Nov 2011; Published Online: 28 Nov 2011. * Correspondence: Dr. Iain Stitt, Institute for Neurophysiology and Pathophysiology, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany, i.stitt@uke.de Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Iain Stitt Edgar Galindo-Leon Florian Pieper Gerhard Engler Andreas Engel Google Iain Stitt Edgar Galindo-Leon Florian Pieper Gerhard Engler Andreas Engel Google Scholar Iain Stitt Edgar Galindo-Leon Florian Pieper Gerhard Engler Andreas Engel PubMed Iain Stitt Edgar Galindo-Leon Florian Pieper Gerhard Engler Andreas Engel Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Visual Receptive Field Properties of Neurons in the Superficial Superior Colliculus of the Mouse

The mouse is a promising model in the study of visual system function and development because of available genetic tools. However, a quantitative analysis of visual receptive field properties had not been performed in the mouse superior colliculus (SC) despite its importance in mouse vision and its usefulness in developmental studies. We have made single-unit extracellular recordings from superficial layers of the SC in urethane-anesthetized C57BL/6 mice. We first map receptive fields with flashing spot stimuli and show that most SC neurons have spatially overlapped ON and OFF subfields. With drifting sinusoidal gratings, we then determine the tuning properties of individual SC neurons, including selectivity for stimulus direction and orientation, spatial frequency tuning, temporal frequency tuning, response linearity, and size preference. A wide range of receptive field sizes and selectivity are observed across the population and in various subtypes of SC neurons identified morphologically. In particular, orientation-selective responses are discovered in the mouse SC, and they are not affected by cortical lesion or long-term visual deprivation. However, ON/OFF characteristics and spatial frequency tuning of SC neurons are influenced by cortical inputs and require visual experience during development. Together, our results provide essential information for future investigations on the functional development of the superior colliculus.