fMRI Reveals How Pain Modulates Visual Object Processing in the Ventral Visual Stream

We examined the organization and function of the ventral object processing pathway. The prevailing theoretical approach in this field holds that the ventral object processing stream has a modular organization, in which visual perception is carried out in posterior regions and visual memory is carried out, independently, in the anterior temporal lobe. In contrast, recent work has argued against this modular framework, favoring instead a continuous, hierarchical account of cognitive processing in these regions. We join the latter group and illustrate our view with simulations from a computational model that extends the perceptual-mnemonic feature-conjunction model of visual discrimination proposed by Bussey and Saksida [Bussey, T. J., & Saksida, L. M. The organization of visual object representations: A connectionist model of effects of lesions in perirhinal cortex. European Journal of Neuroscience, 15, 355–364, 2002]. We use the extended model to revisit early data from Iwai and Mishkin [Iwai, E., & Mishkin, M. Two visual foci in the temporal lobe of monkeys. In N. Yoshii & N. Buchwald (Eds.), Neurophysiological basis of learning and behavior (pp. 1–11). Japan: Osaka University Press, 1968]; this seminal study was interpreted as evidence for the modularity of visual perception and visual memory. The model accounts for a double dissociation in monkeys' visual discrimination performance following lesions to different regions of the ventral visual stream. This double dissociation is frequently cited as evidence for separate systems for perception and memory. However, the model provides a parsimonious, mechanistic, single-system account of the double dissociation data. We propose that the effects of lesions in ventral visual stream on visual discrimination are due to compromised representations within a hierarchical representational continuum rather than impairment in a specific type of learning, memory, or perception. We argue that consideration of the nature of stimulus representations and their processing in cortex is a more fruitful approach than attempting to map cognition onto functional modules.

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Activity in perirhinal and entorhinal cortex predicts observer-specific perceived visual similarities between objects

10.1101/2021.01.21.427602 ◽

2021 ◽

Author(s):

Kayla M. Ferko ◽

Anna Blumenthal ◽

Chris B. Martin ◽

Daria Proklova ◽

Lisa M. Saksida ◽

...

Keyword(s):

Entorhinal Cortex ◽

Activity Patterns ◽

Discrimination Performance ◽

Visual Environment ◽

Visual Stream ◽

Object Processing ◽

Specific Manner ◽

Similarity Structure ◽

Ventral Visual Stream ◽

New Evidence

AbstractObservers perceive their visual environment in unique ways. How ventral visual stream (VVS) regions represent subjectively perceived object characteristics remains poorly understood. We hypothesized that the visual similarity between objects that observers perceive is reflected with highest fidelity in neural activity patterns in perirhinal and anterolateral entorhinal cortex at the apex of the VVS object-processing hierarchy. To address this issue with fMRI, we administered a task that required discrimination between images of exemplars from real-world categories. Further, we obtained ratings of perceived visual similarities. We found that perceived visual similarities predicted discrimination performance in an observer-specific manner. As anticipated, activity patterns in perirhinal and anterolateral entorhinal cortex predicted perceived similarity structure, including those aspects that are observer-specific, with higher fidelity than any other region examined. Our findings provide new evidence that representations of the visual world at the apex of the VVS differ across observers in ways that influence behaviour.

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Receptive field properties of neurons in the macaque anterior intraparietal area

Journal of Neurophysiology ◽

10.1152/jn.01037.2014 ◽

2016 ◽

Vol 115 (3) ◽

pp. 1542-1555 ◽

Cited By ~ 7

Author(s):

Maria C. Romero ◽

Peter Janssen

Keyword(s):

Receptive Field ◽

Anterior Part ◽

Large Fraction ◽

Visual Object ◽

Visually Guided ◽

Central Visual Field ◽

Visual Stream ◽

Local Maxima ◽

Ventral Visual Stream ◽

Dorsal Visual Stream

Visual object information is necessary for grasping. In primates, the anterior intraparietal area (AIP) plays an essential role in visually guided grasping. Neurons in AIP encode features of objects, but no study has systematically investigated the receptive field (RF) of AIP neurons. We mapped the RF of posterior AIP (pAIP) neurons in the central visual field, using images of objects and small line fragments that evoked robust responses, together with less effective stimuli. The RF sizes we measured varied between 3°2 and 90°2, with the highest response either at the fixation point or at parafoveal positions. A large fraction of pAIP neurons showed nonuniform RFs, with multiple local maxima in both ipsilateral and contralateral hemifields. Moreover, the RF profile could depend strongly on the stimulus used to map the RF. Highly similar results were obtained with the smallest stimulus that evoked reliable responses (line fragments measuring 1–2°). The nonuniformity and dependence of the RF profile on the stimulus in pAIP were comparable to previous observations in the anterior part of the lateral intraparietal area (aLIP), but the average RF of pAIP neurons was located at the fovea whereas the average RF of aLIP neurons was located parafoveally. Thus nonuniformity and stimulus dependence of the RF may represent general RF properties of neurons in the dorsal visual stream involved in object analysis, which contrast markedly with those of neurons in the ventral visual stream.

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Wiring Up Vision: Minimizing Supervised Synaptic Updates Needed to Produce a Primate Ventral Stream

10.1101/2020.06.08.140111 ◽

2020 ◽

Author(s):

Franziska Geiger ◽

Martin Schrimpf ◽

Tiago Marques ◽

James J. DiCarlo

Keyword(s):

Visual System ◽

Visual Processing ◽

Ventral Stream ◽

Visual Object ◽

Visual Object Recognition ◽

Visual Stream ◽

Ongoing Research ◽

Ventral Visual Stream ◽

And Behavior ◽

The Brain

AbstractAfter training on large datasets, certain deep neural networks are surprisingly good models of the neural mechanisms of adult primate visual object recognition. Nevertheless, these models are poor models of the development of the visual system because they posit millions of sequential, precisely coordinated synaptic updates, each based on a labeled image. While ongoing research is pursuing the use of unsupervised proxies for labels, we here explore a complementary strategy of reducing the required number of supervised synaptic updates to produce an adult-like ventral visual stream (as judged by the match to V1, V2, V4, IT, and behavior). Such models might require less precise machinery and energy expenditure to coordinate these updates and would thus move us closer to viable neuroscientific hypotheses about how the visual system wires itself up. Relative to the current leading model of the adult ventral stream, we here demonstrate that the total number of supervised weight updates can be substantially reduced using three complementary strategies: First, we find that only 2% of supervised updates (epochs and images) are needed to achieve ~80% of the match to adult ventral stream. Second, by improving the random distribution of synaptic connectivity, we find that 54% of the brain match can already be achieved “at birth” (i.e. no training at all). Third, we find that, by training only ~5% of model synapses, we can still achieve nearly 80% of the match to the ventral stream. When these three strategies are applied in combination, we find that these new models achieve ~80% of a fully trained model’s match to the brain, while using two orders of magnitude fewer supervised synaptic updates. These results reflect first steps in modeling not just primate adult visual processing during inference, but also how the ventral visual stream might be “wired up” by evolution (a model’s “birth” state) and by developmental learning (a model’s updates based on visual experience).

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Preserved Expert Object Recognition in a Case of Visual Hemiagnosia

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_01193 ◽

2018 ◽

Vol 30 (2) ◽

pp. 131-143 ◽

Cited By ~ 1

Author(s):

Johannes Rennig ◽

Sonja Cornelsen ◽

Helmut Wilhelm ◽

Marc Himmelbach ◽

Hans-Otto Karnath

Keyword(s):

Object Recognition ◽

Expert Knowledge ◽

Early Stage ◽

Visual Object ◽

Top Down ◽

Visual Stream ◽

Object Processing ◽

Visual Expertise ◽

Everyday Objects ◽

The Right

We examined a stroke patient (HWS) with a unilateral lesion of the right medial ventral visual stream, involving the right fusiform and parahippocampal gyri. In a number of object recognition tests with lateralized presentations of target stimuli, HWS showed significant symptoms of hemiagnosia with contralesional recognition deficits for everyday objects. We further explored the patient's capacities of visual expertise that were acquired before the current perceptual impairment became effective. We confronted him with objects he was an expert for already before stroke onset and compared this performance with the recognition of familiar everyday objects. HWS was able to identify significantly more of the specific (“expert”) than of the everyday objects on the affected contralesional side. This observation of better expert object recognition in visual hemiagnosia allows for several interpretations. The results may be caused by enhanced information processing for expert objects in the ventral system in the affected or the intact hemisphere. Expert knowledge could trigger top–down mechanisms supporting object recognition despite of impaired basic functions of object processing. More importantly, the current work demonstrates that top–down mechanisms of visual expertise influence object recognition at an early stage, probably before visual object information propagates to modules of higher object recognition. Because HWS showed a lesion to the fusiform gyrus and spared capacities of expert object recognition, the current study emphasizes possible contributions of areas outside the ventral stream to visual expertise.

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Perceptual processing in the ventral visual stream requires area TE but not rhinal cortex

eLife ◽

10.7554/elife.36310 ◽

2018 ◽

Vol 7 ◽

Cited By ~ 1

Author(s):

Mark AG Eldridge ◽

Narihisa Matsumoto ◽

John H Wittig ◽

Evan C Masseau ◽

Richard C Saunders ◽

...

Keyword(s):

Final Stage ◽

Short Term Memory ◽

Visual Object ◽

Short Term ◽

Visual Stream ◽

Term Memory ◽

Clear Cut ◽

Rhinal Cortex ◽

Ventral Visual Stream ◽

Area Te

There is an on-going debate over whether area TE, or the anatomically adjacent rhinal cortex, is the final stage of visual object processing. Both regions have been implicated in visual perception, but their involvement in non-perceptual functions, such as short-term memory, hinders clear-cut interpretation. Here, using a two-interval forced choice task without a short-term memory demand, we find that after bilateral removal of area TE, monkeys trained to categorize images based on perceptual similarity (morphs between dogs and cats), are, on the initial viewing, badly impaired when given a new set of images. They improve markedly with a small amount of practice but nonetheless remain moderately impaired indefinitely. The monkeys with bilateral removal of rhinal cortex are, under all conditions, indistinguishable from unoperated controls. We conclude that the final stage of the integration of visual perceptual information into object percepts in the ventral visual stream occurs in area TE.

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Using Convolutional Neural Networks to measure the contribution of visual features to the representation of object animacy in the brain

10.31237/osf.io/fxz4q ◽

2019 ◽

Cited By ~ 1

Author(s):

Sushrut Thorat

Keyword(s):

Neural Networks ◽

Convolutional Neural Networks ◽

Temporal Cortex ◽

Large Degree ◽

Visual Features ◽

Visual Feature ◽

Visual Stream ◽

Feature Information ◽

Ventral Visual Stream ◽

Animal Images

A mediolateral gradation in neural responses for images spanning animals to artificial objects is observed in the ventral temporal cortex (VTC). Which information streams drive this organisation is an ongoing debate. Recently, in Proklova et al. (2016), the visual shape and category (“animacy”) dimensions in a set of stimuli were dissociated using a behavioural measure of visual feature information. fMRI responses revealed a neural cluster (extra-visual animacy cluster - xVAC) which encoded category information unexplained by visual feature information, suggesting extra-visual contributions to the organisation in the ventral visual stream. We reassess these findings using Convolutional Neural Networks (CNNs) as models for the ventral visual stream. The visual features developed in the CNN layers can categorise the shape-matched stimuli from Proklova et al. (2016) in contrast to the behavioural measures used in the study. The category organisations in xVAC and VTC are explained to a large degree by the CNN visual feature differences, casting doubt over the suggestion that visual feature differences cannot account for the animacy organisation. To inform the debate further, we designed a set of stimuli with animal images to dissociate the animacy organisation driven by the CNN visual features from the degree of familiarity and agency (thoughtfulness and feelings). Preliminary results from a new fMRI experiment designed to understand the contribution of these non-visual features are presented.

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