scholarly journals 'Artiphysiology' reveals V4-like shape tuning in a deep network trained for image classification

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Dean A Pospisil ◽  
Anitha Pasupathy ◽  
Wyeth Bair
Keyword(s):  
Single Unit ◽  
Image Categorization ◽  
Translation Invariant ◽  
Area V4 ◽  
Neural Representations ◽  
Boundary Information ◽  
Boundary Curvature ◽  
Shape Tuning ◽  
Artificial Network ◽  
The Relationship

Deep networks provide a potentially rich interconnection between neuroscientific and artificial approaches to understanding visual intelligence, but the relationship between artificial and neural representations of complex visual form has not been elucidated at the level of single-unit selectivity. Taking the approach of an electrophysiologist to characterizing single CNN units, we found many units exhibit translation-invariant boundary curvature selectivity approaching that of exemplar neurons in the primate mid-level visual area V4. For some V4-like units, particularly in middle layers, the natural images that drove them best were qualitatively consistent with selectivity for object boundaries. Our results identify a novel image-computable model for V4 boundary curvature selectivity and suggest that such a representation may begin to emerge within an artificial network trained for image categorization, even though boundary information was not provided during training. This raises the possibility that single-unit selectivity in CNNs will become a guide for understanding sensory cortex.

Coding of directional information by single neurones in the S-segment of the FM bat, Myotis lucifugus

1980 ◽  
Vol 87 (1) ◽  
pp. 203-216
Author(s):  
P. H. Jen
Keyword(s):  
Single Unit ◽  
Median Plane ◽  
Myotis Lucifugus ◽  
Directional Information ◽  
Stimulus Pulse ◽  
Fm Bat ◽  
Single Neurones ◽  
The Relationship ◽  
Correct Level ◽  
Stimulus Direction

1. Response parameters of S-segment neurones of the FM bat Myotis lucifugus were measured as a sound was delivered from different azimuthal angles around the animal's head. 2. The response parameters investigated were the amplitude and threshold of the evoked potential (N3) of the S-segment, together with the threshold, latency and number of impulses (per stimulus pulse) of single units. 3. All the neurones studied had their lowest thresholds either at 20-40 degrees contralateral, or 20-40 degrees ipsilateral or at the front (0 degrees). 4. The amplitude of the sound affected the relationship between stimulus direction and the amplitude of a non-monotonic N3, and the relationship between stimulus direction and the number of impulses of a non-monotonic single unit. It had so such effects with a monotonic N3 and a monotonic single unit. 5. From a study of N3 amplitudes and numbers of impulses of single neurones, it appeared that an azimuthal difference as small as 3 degrees could be easily coded at a 95% correct level with stimuli presented at around 20 degrees ipsilateral, 20 degrees contralateral, and at the front. 6. The inter-aural pressure difference (IPD), which is considered an essential cue for echolocation in Myotis (Shimozawa et al. 1974), changed linearly with angle from 0 to 40 degrees lateral at a rate of 0.4 dB/degree for sounds between 33.5 and 49.0 kHz. 7. Assuming the just-detectable IPD to be 0.5 dB (as in man), the minimum detectable azimuthal difference of Myotis around the median plane would be 1.25 degrees.

Spinal Unit Activity During Synchronization of a Convulsive Type (Strychnine Tetanus)

1956 ◽  
Vol 186 (2) ◽  
pp. 263-270 ◽  
Author(s):  
Carlo A. Terzuolo ◽  
Bo E. Gernandt
Keyword(s):  
Spinal Cord ◽  
Intravenous Injection ◽  
Unit Activity ◽  
Single Unit ◽  
Slow Waves ◽  
Single Unit Activity ◽  
Oscillatory Potential ◽  
Convulsive Activity ◽  
Decerebrate Cat ◽  
The Relationship

Single unit activity during convulsive synchronized discharge and the relationship between unit activity and slow ‘waves’ were studied in the spinal cord of the decerebrate cat after intravenous injection of strychnine. Steel needle microelectrodes were used. Units did discharge in burst (from 1 to 5 impulses) only in coincidence with the slow oscillatory potential (tetanic ‘waves’). The firing is confined to the rising phase of this potential. Changes in d.c. state related to a convulsive activity were also studied. A relationship was found between frequency of the tetanic rhythm and d.c. state of spinal structures. The mechanisms of synchronization and rhythmicity of the convulsive activity in a population of neurons are discussed in connection with the problem of interaction between units.

SYNCHRONOUS CHAOS IN HIGH-DIMENSIONAL MODULAR NEURAL NETWORKS

1996 ◽  
Vol 06 (11) ◽  
pp. 2055-2067 ◽  
Author(s):  
THOMAS WENNEKERS ◽  
FRANK PASEMANN
Keyword(s):  
Neural Networks ◽  
Single Unit ◽  
System Size ◽  
Single Units ◽  
High Dimensional ◽  
Coexisting Attractors ◽  
Modular Neural Networks ◽  
Coupled Maps ◽  
Low Dimensional ◽  
The Relationship

The relationship between certain types of high-dimensional neural networks and low-dimensional prototypical equations (neuromodules) is investigated. The high-dimensional systems consist of finitely many pools containing identical, dissipative and nonlinear single-units operating in discrete time. Under the assumption of random connections inside and between pools, the system can be reduced to a set of only a few equations, which — asymptotically in time and system size — describe the behavior of every single unit arbitrarily well. This result can be viewed as synchronization of the single units in each pool. It is stated as a theorem on systems of nonlinear coupled maps, which gives explicit conditions on the single unit dynamics and the nature of the random connections. As an application we compare a 2-pool network with the corresponding two-dimensional dynamics. The bifurcation diagrams of both systems become very similar even for moderate system size (N=50) and large disorder in the connection strengths (50% of mean), despite the fact, that the systems exhibit fairly complex behavior (quasiperiodicity, chaos, coexisting attractors).

scholarly journals The Fine Structure of Shape Tuning in Area V4

Neuron ◽  
2013 ◽  
Vol 78 (6) ◽  
pp. 1102-1115 ◽  
Author(s):  
Anirvan S. Nandy ◽  
Tatyana O. Sharpee ◽  
John H. Reynolds ◽  
Jude F. Mitchell
Keyword(s):  
Fine Structure ◽  
Area V4 ◽  
Shape Tuning

scholarly journals Building the Tourist Destination Through Multiple Semiotic Modes

2021 ◽  
Vol 11 (4) ◽  
pp. 83
Author(s):  
Olga Denti
Keyword(s):  
Single Unit ◽  
Functional Approach ◽  
Mobile Technologies ◽  
Visual Design ◽  
Cultural Meanings ◽  
Text And Image ◽  
Tourist Destination ◽  
Tourist Gaze ◽  
The Relationship ◽  
Over Time

Over time, multiple semiotic modes have contributed in different ways to the construction and exchange of cultural meanings in Tourism Discourse. This has required the analysis and understanding of the modes employed and the recontextualization and adaptation of texts and images, especially to the new web genres. Nowadays, the tourist experience is mediated by personal, digital, and mobile technologies, which redirect the tourist gaze and become the mediator between the traveler and the tourist destination. Consequently, the tourism text must be considered as a single unit, where different semiotic resources intermingle to enhance its communicative strength. The present study will attempt to propose a methodology to read and write tourism texts in a comprehensive and effective way. It will start by focusing on the relationship between text and image to see how they co-exist in the page and in the way the page is arranged. Then, it will apply a functional approach to the analysis of such semiotic units. The result will show how the boundaries between image and text have become blurred, and textuality is built less through verbal syntax and more through rhetorical visual design.

scholarly journals THE RITUAL TERMINOLOGY OF MARRIAGE: TRANSLATION EQUIVALENTS, SEMANTIC DYNAMICS AND VALUE CONCEPTS

2019 ◽  
pp. 261-276
Author(s):  
Oleh Tyshscenko ◽  
Maria Malaniuk ◽  
Iryna Popko
Keyword(s):  
Image Categorization ◽  
Marriage Ceremony ◽  
Culture Material ◽  
Pragmatic Analysis ◽  
Before And After ◽  
French And English ◽  
Cultural Component ◽  
Cross Language ◽  
Good And Evil ◽  
The Relationship

The article presents the semantic and pragmatic analysis of ethno-cultural parallels related to conceptosphere WEDDING and MARRIAGE on the base of searching cross-language equivalents and analogues to transmit a specific ethno-cultural content, ways of transformations and related value concepts’ translation, sequential structural-semantic modeling through the lens of a joint or an inner form; synonymous variants of paroemias are being determined in a comparative perspective. The material for the analysis was the dictionaries of proverbs, dictionaries of dialects, bilingual phraseological dictionaries of the analyzed languages, and ethnographic descriptions of the marriage ceremony, dictionaries of beliefs and symbols. Common evaluative component of reality conceptualization studied in the context of paroemia and image categorization, demonstrates different gender and socio-cultural markedness in the sustainable expressions, proverbs and sayings, in Polish, Ukrainian, Slovak, French and English languages. Special attention is given to the mental-semiotic correlates of key ritual terms and related symbols and concepts, phraseological relations, sustainable comparisons that are presented in the magic marriage and beliefs. The household contexts and stereotypes, norms of behavior associated with the relationship between man and woman before and after marriage, mentioned in the universal categories of good and evil, happiness and misery, successes, failures, old-young and other nominatively characterized principles of imaginative and accolade nomination are also being analysed. In some cases, the processes of semantic dynamics and transformation of marriage and ritual realities and symbols in paroemina contexts are studied, alongside with the specifics of the emergence of nomens with secondary evaluative function. The latter reflects different facts, a kind of reality of a particular culture (material or spiritual), known as nonequivalent vocabulary and phraseology with the national-cultural component of the semantics.

scholarly journals Establishing the Symbolic Association of the Concept of 'Youth' in the British and American Literary Discourse in the 19th-21st Centuries

Linguaculture ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Olga Beshlei
Keyword(s):  
Single Unit ◽  
Textual Analysis ◽  
Symbolic Meaning ◽  
Literary Discourse ◽  
Semantic Change ◽  
Cultural Images ◽  
Associative Chain ◽  
Social Novels ◽  
The Relationship ◽  
American Authors

The article deals with axiologically marked symbolic associations related to the sociocultural phenomenon of youth. The research is conducted on the basis of social novels by British and American authors of the nineteenth, twentieth and twenty-first centuries. The symbolic meaning of the concept is formed in a textual context and motivated by cultural images, ideas and values. It does not cause an internal semantic change but complements the range of meaning in the process of discourse implementation. The study of the symbolic embodiment of the concept of YOUTH in English literary discourse is not limited to the analysis of individual words but requires conducting an interpretative-textual analysis of the coherent discourse situation, indicating the formation of an associative chain during concept actualization. Chain elements are linked internally into a single unit, forming an associative group. The symbol, carrying the axiological potential of its culture, operates in inseparable unity with the axiological component of the concept under study. The data clarify the relationship between positive and negative axiological representations of the concept.

Shape Representation in Area V4: Position-Specific Tuning for Boundary Conformation

2001 ◽  
Vol 86 (5) ◽  
pp. 2505-2519 ◽  
Author(s):  
Anitha Pasupathy ◽  
Charles E. Connor
Keyword(s):  
Shape Representation ◽  
Single Type ◽  
Complex Objects ◽  
Axis Orientation ◽  
Area V4 ◽  
Multi Stage ◽  
Complex Boundary ◽  
Concave Boundary ◽  
The Right ◽  
Shape Tuning

Visual shape recognition in primates depends on a multi-stage pathway running from primary visual cortex (V1) to inferotemporal cortex (IT). The mechanisms by which local shape signals from V1 are transformed into selectivity for abstract object categories in IT are unknown. One approach to this issue is to investigate shape representation at intermediate stages in the pathway, such as area V4. We studied 109 V4 cells that appeared sensitive to complex shape in preliminary tests. To achieve a more complete picture of shape representation in V4, we tested each cell with a set of 366 stimuli, constructed by systematically combining convex and concave boundary elements into closed shapes. Using this large, diverse stimulus set, we found that all the cells in our sample responded to a wide variety of shapes and did not appear to encode any single type of global shape. However, for most cells the shapes evoking strongest responses were characterized by a consistent type of boundary conformation at a specific position within the stimulus. For example, a given cell might be tuned for shapes containing concave curvature at the right, with other parts of the shape having little or no effect on responses. Many cells were tuned for more complex boundary configurations (e.g., a convex angle adjacent to a concave curve). We quantified this kind of shape tuning with Gaussian functions on a curvature × position domain. These tuning functions fit the neural responses much better than tuning functions based on edge or axis orientation. Thus individual V4 cells appear to encode moderately complex boundary information at specific locations within larger shapes. This finding suggests that, at intermediate stages in the V1-IT transformation, complex objects are represented at least partly in terms of the configurations and positions of their contour components.

Representation of Stereoscopic Depth Based on Relative Disparity in Macaque Area V4

2007 ◽  
Vol 98 (1) ◽  
pp. 241-252 ◽  
Author(s):  
Kazumasa Umeda ◽  
Seiji Tanabe ◽  
Ichiro Fujita
Keyword(s):  
Stereoscopic Vision ◽  
Stereoscopic Depth ◽  
Common Mechanism ◽  
Tuning Curves ◽  
Area V4 ◽  
Neural Representations ◽  
Area V2 ◽  
Random Dot Stereogram ◽  
V4 Neurons ◽  
Background Feature

Stereoscopic vision is characterized by greater visual acuity when a background feature serves as a reference. When a reference is present, the perceived depth of an object is predominantly dependent on this reference. Neural representations of stereoscopic depth are expected to have a relative frame of reference. The conversion of absolute disparity encoded in area V1 to relative disparity begins in area V2, although the information encoded in this area appears to be insufficient for stereopsis. This study examines whether relative disparity is encoded in a higher cortical area. We recorded the responses of V4 neurons from macaque monkeys to various combinations of the absolute disparities of two features: the center patch and surrounding annulus of a dynamic random-dot stereogram. We analyzed the effects of the disparity of the surrounding annulus on the tuning for the disparity of the center patch; the tuning curves of relative-disparity–selective neurons for disparities of the center patch should shift with changes in the disparity of the surrounding annulus. Most V4 tuning curves exhibited significant shifts. The magnitudes of the shifts were larger than those reported for V2 neurons and smaller than that expected for an ideal relative-disparity–selective cell. No correlation was found between the shift magnitude and the degree of size suppression, suggesting that the two phenomena are not the result of a common mechanism. Our results suggest that the coding of relative disparity advances as information flows along the cortical pathway that includes areas V2 and V4.

Determination of Mechanical Parameters of Reservoir Landslide Based on Back Analysis Using Evolutionary Artificial Network

2012 ◽  
Vol 170-173 ◽  
pp. 729-734
Author(s):  
Fan Zhen Meng ◽  
Shao Jun Li ◽  
Zhen Hua Zhang
Keyword(s):  
Neural Network ◽  
Back Analysis ◽  
Mechanical Parameters ◽  
Three Gorges ◽  
Geological Materials ◽  
Highly Nonlinear ◽  
Artificial Network ◽  
The Relationship ◽  
Rock And Soil

Back analysis of displacement is an effective method for parameter recognition in geotechnical engineering. As rock and soil are complex geological materials, the relationship between the mechanical parameters of slope sliding mass and its displacement is incompletely quantified and highly nonlinear, but traditional back analysis of displacement has poor adaptability for this. So in this paper an integrating method of genetic algorithm, neural network and numerical analysis (GA-NN) is presented to carry out back analysis for mechanical parameters of slope sliding mass, and procedures to perform the intelligent back analysis are described in detail. Finally, this new method is applied and verified by a practical landslide in the reservoir area of Three Gorges, the results indicate the method is efficient for determination of mechanical parameters of sliding mass.

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