Sequential Activity of Simultaneously Recorded Neurons in the Superior Colliculus During Curved Saccades

2003 ◽  
Vol 90 (3) ◽  
pp. 1887-1903 ◽  
Author(s):  
Nicholas L. Port ◽  
Robert H. Wurtz
Keyword(s):  
Superior Colliculus ◽  
Saccadic Eye Movements ◽  
The Other ◽  
Saccade Target ◽  
Relative Timing ◽  
Average Model ◽  
Rapid Sequence ◽  
Sequential Activation ◽  
The One ◽  
The Brain

The visual world presents multiple potential targets that can be brought to the fovea by saccadic eye movements. These targets produce activity at multiple sites on a movement map in the superior colliculus (SC), an area of the brain related to saccade generation. The saccade made must result from competition between the populations of neurons representing these many saccadic goals, and in the present experiments we used multiple moveable microelectrodes to follow this competition. We recorded simultaneously from two sites on the SC map where each site was related to a different saccade target. The two targets appeared in rapid sequence, and the monkey was rewarded for making a saccade toward the one appearing first. Our study concentrated on trials in which the monkey made strongly curved saccades that were directed first toward one target and then toward the other. These curved saccades activated both sites on the SC map as they veered from one target to the other. The major finding was that the strongly curved saccades were preceded by sequential activity in the two neurons as indicated by three observations: the firing rate for the neuron related to the first target reached its peak earlier than did the rate of the neuron for the second target; the timing of the peak activity of the two neurons was related to the beginning and end of the saccade curvature; a weighted vector-average model based on the activity of the two neurons predicted the timing of saccade curvature. Straight averaging saccades ended between the targets so that they did not go to either target, and they were accompanied by simultaneous rather than sequential activation of the two neurons. Thus when multiple populations of neurons are active on the SC movement map, the resulting saccade is determined by the relative timing of the activity in the populations as well as their magnitude. In contrast, SC activity at the two sites did not predict the final direction of the saccade, and several control experiments found insufficient activity at other sites on the SC map to account for that final direction. We conclude that the SC neuronal activity predicts the timing of the saccade curvature, but not the final direction of the trajectory. These observations are consistent with SC activity being critical in selecting the goal of the saccade, but not in determining the exact trajectory.

scholarly journals Bio-Inspired Modality Fusion for Active Speaker Detection

2021 ◽  
Vol 11 (8) ◽  
pp. 3397
Author(s):  
Gustavo Assunção ◽  
Nuno Gonçalves ◽  
Paulo Menezes
Keyword(s):  
Superior Colliculus ◽  
Visual Information ◽  
Human Beings ◽  
Validation Process ◽  
Detection Approach ◽  
Wide Range ◽  
Speaker Detection ◽  
The One ◽  
The Brain ◽  
Fusion Ability

Human beings have developed fantastic abilities to integrate information from various sensory sources exploring their inherent complementarity. Perceptual capabilities are therefore heightened, enabling, for instance, the well-known "cocktail party" and McGurk effects, i.e., speech disambiguation from a panoply of sound signals. This fusion ability is also key in refining the perception of sound source location, as in distinguishing whose voice is being heard in a group conversation. Furthermore, neuroscience has successfully identified the superior colliculus region in the brain as the one responsible for this modality fusion, with a handful of biological models having been proposed to approach its underlying neurophysiological process. Deriving inspiration from one of these models, this paper presents a methodology for effectively fusing correlated auditory and visual information for active speaker detection. Such an ability can have a wide range of applications, from teleconferencing systems to social robotics. The detection approach initially routes auditory and visual information through two specialized neural network structures. The resulting embeddings are fused via a novel layer based on the superior colliculus, whose topological structure emulates spatial neuron cross-mapping of unimodal perceptual fields. The validation process employed two publicly available datasets, with achieved results confirming and greatly surpassing initial expectations.

scholarly journals Evolution in the Brain, Evolution in the Mind: The Hierarchical Brain and the Interface between Psychoanalysis and Neuroscience

2017 ◽  
Vol 19 (3) ◽  
pp. 349-377
Author(s):  
Leonardo Niro Nascimento
Keyword(s):  
Brain Evolution ◽  
The Other ◽  
Common Source ◽  
Evolutionary Models ◽  
Anatomy And Physiology ◽  
Psychodynamically Oriented ◽  
The One ◽  
The Mind ◽  
The Brain ◽  
Shed Light

This article first aims to demonstrate the different ways the work of the English neurologist John Hughlings Jackson influenced Freud. It argues that these can be summarized in six points. It is further argued that the framework proposed by Jackson continued to be pursued by twentieth-century neuroscientists such as Papez, MacLean and Panksepp in terms of tripartite hierarchical evolutionary models. Finally, the account presented here aims to shed light on the analogies encountered by psychodynamically oriented neuroscientists, between contemporary accounts of the anatomy and physiology of the nervous system on the one hand, and Freudian models of the mind on the other. These parallels, I will suggest, are not coincidental. They have a historical underpinning, as both accounts most likely originate from a common source: John Hughlings Jackson's tripartite evolutionary hierarchical view of the brain.

Some Economic Aspects of the Brain Drain

1979 ◽  
Vol 9 (4) ◽  
pp. 7-14
Author(s):  
Harry G. Johnson
Keyword(s):  
United States ◽  
North America ◽  
Brain Drain ◽  
The United States ◽  
The Other ◽  
Economic Aspects ◽  
National State ◽  
The One ◽  
Professional People ◽  
The Brain

The concept of “brain drain” is in its origins a nationalistic concept, by which is meant a concept that visualizes economic and cultural welfare in terms of the welfare of the residents of a national state or region, viewed as a totality, and excludes from consideration both the welfare of people born in that region who choose to leave it, and the welfare of the outside world in general. Moreover, though the available statistics are far from adequate on this point, there is generally assumed to be a net flow of trained professional people from the former colonial territories to the ex-imperial European nations, and from Europe and elsewhere to North America and particularly the United States. The concept thus lends itself easily to the expression of anti-colonial sentiments on the one hand, and anti-American sentiments on the other. The expression of such sentiments can be dignified by the presentation of brain drain as a serious economic and cultural problem, by relying on nationalistic sentiments and assumptions and ignoring the principles of economics—especially the principle that in every transaction there is both a demand and a supply—or by elevating certain theoretical economic possibilities into presumed hard facts.

Herbert Mac Cabe’s Philosophical Anthropology

Politeia ◽  
2019 ◽  
Vol 1 (4) ◽  
pp. 238-260
Author(s):  
Franco Manni ◽  
Keyword(s):  
Philosophical Anthropology ◽  
External World ◽  
The Other ◽  
Human Being ◽  
Language System ◽  
Other Hand ◽  
The One ◽  
The Individual ◽  
The Brain ◽  
Individual Human

From the ideas of Aristotle, De Saussure and Wittgenstein, philosopher Herbert McCabe elaborated an original anthropology. 'Meaning' means: the role played by a part towards the whole. Senses are bodily organs and sensations allow an animal to get fragments of the external world which become 'meaningful' for the behaviour of the whole animal Besides sensations, humans are ‘linguistic animals’ because through words they are able to 'communicate', that is, to share a peculiar kind of meanings: concepts. Whereas, sense-images are stored physically in our brain and cannot be shared, even though we can relate to sense-images by words (speech coincides with thought). However, concepts do not belong to the individual human being qua individual, but to an interpersonal entity: the language system. Therefore, on the one hand, to store images is a sense-power and an operation of the brain, whereas the brain (quite paradoxically!) is not in itself the organ of thought. On the other hand, concepts do not exist on their own.

Ordering Disorder

2013 ◽  
Author(s):  
George Graham
Keyword(s):  
Mental Disorders ◽  
Mental Disorder ◽  
Type A ◽  
The Other ◽  
Brain Disorder ◽  
The Difference ◽  
The One ◽  
The Brain

The basic claims of the chapter are, first, that mental disorders are not best understood as types of brain disorder, even though mental disorders are based in the brain. And, second, that the difference between the two sorts of disorders can be illuminated by the sorts of treatment or therapy that may work for the one type (a mental disorder) but not for the other type (a brain disorder). In the discussion some of the diagnostic implications and difficulties associated with these two basic claims are outlined.

THE ALHACENIAN ACCOUNT OF SPATIAL PERCEPTION AND ITS EPISTEMOLOGICAL IMPLICATIONS

2005 ◽  
Vol 15 (2) ◽  
pp. 219-240 ◽  
Author(s):  
A. MARK SMITH
Keyword(s):  
Seventeenth Century ◽  
Visual Information ◽  
Spatial Perception ◽  
Crystalline Lens ◽  
The Other ◽  
External Objects ◽  
Latin West ◽  
Visual Imaging ◽  
The One ◽  
The Brain

From the late thirteenth to the early seventeenth century, the process of visual imaging was understood in the Latin West as an essentially subjective act initiated by the eye and completed by the brain. The crystalline lens took center stage in this act, its role determined by its peculiar physical and sensitive capacities. As a physical body, on the one hand, it was disposed to accept the physical impressions of light and color radiating to it from external objects. As a sensitive body, on the other hand, it was enabled by the visual spirit flowing to it from the brain to feel those impressions visually. Acting as a sentient selector of visual information, the lens transformed the brute physical impressions of light and color into visual impressions. These, in turn, gave rise to perceptual “depictions” that were passed back along the stream of visual spirits to the brain. Known in Scholastic parlance as “intentional species,” these depictions served as virtual representations of their generating objects. As such, they provided the wherewithal not only for perception, but also for conception and cognition.

scholarly journals Some observations on the functions of the nervous system, and the relation which they bear to the other vital functions

1833 ◽  
Vol 2 ◽  
pp. 373-375
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
The Other ◽  
Vital Functions ◽  
Injured Part ◽  
Voluntary Motion ◽  
The One ◽  
Thoracic And Abdominal ◽  
Brain And Spinal Cord ◽  
The Brain

The intention of the author in the present paper, is, not to bring forwards any new facts, but to take a general review of the inferences deducible from the series of facts detailed by him in previous papers communicated to this Society. He divides the nerves into two classes, essentially differing in their functions. The first comprehends those nerves, which, proceeding directly from the brain and spinal cord to other parts, convey in the one case to those parts the influence of those organs only from which they originate, and thus excite to con­traction the muscles of voluntary motion ; and in the other case transmit to the sensorium impressions made on the parts to which they are distributed. The second class comprises what may betermed the Ganglionic nerves, or those which enter ganglions, pro­perly so called; that term being limited to such protuberances only as receive branches of nerves proceeding from the brain and spiral cord. These nerves are distributed more especially to the vital or­ gans, as the thoracic and abdominal viscera, and to the muscles sub­servient to their functions. The nerves belonging to this class also convey impressions to the sensorium, and occasionally excite the muscles of involuntary motion, which, in common with all muscles, possess an inherent power of contractility dependent solely on their own mechanism, and which in ordinary cases are excited by stimuli peculiar to themselves. But the most important function of the gan­glionic nerves, is that of supporting the processes of secretion and assimilation, which require for their performance the combined influ­ence of the whole brain and spinal cord. Viewed as a whole, the system of ganglionic nerves, therefore, constitutes, in the strictest sense, a vital organ. Thus the sensorium, though connected by means of the cerebral and spinal nerves only partially with the organs of sense and voluntary motion, is, by means of the ganglionic nerves, connected generally with all the functions of the animal body. Hence affections of the stomach and other vital organs extend their influence over every part of the frame; while those of a muscle of voluntary motion, or even of an organ of sense, although possessing greater sensibility, are confined to the injured part. From a due consideration of the phenomena of the nervous system, it would appear that they imply the operation of more than one prin­ciple of action. The sensorial power is wholly distinct from the ner­vous power; the former residing chiefly in the brain, while the latter belongs equally to the spinal cord and brain, and may be exercised independently of the sensorial power. In like manner, the muscular power resides in the muscles, and may be called into action by various irritations independently of the nervous power, though fre­quently excited by the action of that power. The muscles of volun­tary motion are subjected to the sensorial power through the inter­vention of the nervous system; and those of involuntary motion are also, under certain circumstances, capable of being excited through the nerves by the sensorial power, particularly when under the influ­ence of the passions. The same observation applies also to other actions which properly belong to the nervous power, such as the evolution of caloric from the blood, and the various processes of se­cretion and of assimilation. That the nervous power is in these instances merely the agent of other powers, and is independent of the peculiar organization of the nerves, is proved by the same effects being produced by galvanism, transmitted through conductors diffe­rent from the nerves. The successive subordination of these several powers is shown during death, when the sensorial functions are the first to cease, and the animal no longer feels or wills, but yet the nervous power still continues to exist, as is proved by the nerves be­ing capable, when stimulated, of exciting contractions in the muscles, both of voluntary and of involuntary motion,of producing the evolution of caloric and of renewing the processes of secretion. In like manner the power of contraction, inherent in the muscular fibre, survives the destniction of both the sensorial and nervous powers, having an existence independent of either, although in the entire state of the functions they are subjected to the entire influence of both.

scholarly journals The method of meningostomy and its application in the study of the brain in animals

2021 ◽  
Vol 27 (8) ◽  
pp. 820-821
Author(s):  
A. I. Smirnov ◽  
P. D. Olefirenko
Keyword(s):  
Cerebral Cortex ◽  
Electric Current ◽  
Brain Stimulation ◽  
Thermal Effects ◽  
Brain Injuries ◽  
The Other ◽  
Surgical Methods ◽  
The One ◽  
The Brain ◽  
Gain Access

All surgical methods used in the study of the brain in animals can be combined into two groups: 1) methods of direct and indirect shutdown of a particular part of the brain and 2) methods of non-mediocre brain stimulation by electric current or by mechanical, chemical or thermal effects. In the hands of different experimenters, depending on the goals and objects of research, these basic methods varied to one degree or another. All modifications were aimed at, on the one hand, to avoid brain injuries during trepanation as much as possible, and on the other hand, to gain access to the cerebral cortex without exposing it at the time of the observation itself. As can be judged from the literature collected from E. Abderhalden in Handbuch der biolog. Arbeitsmethoden to a certain extent this has already been achieved.

scholarly journals Om religion og kognition

2005 ◽  
Author(s):  
Armin W. Geertz
Keyword(s):  
Philosophy Of Science ◽  
The Other ◽  
Cognitive Science Of Religion ◽  
The Past ◽  
Cognitive Approaches ◽  
Neurological Research ◽  
The Many ◽  
The One ◽  
Cognitive Study ◽  
The Brain

“On Religion and Cognition: A Brief Historical and Thematic Introduction”. This article is a brief introduction to the cognitive study of religion. Ten problems are identified which serve as the backdrop of the article. These concern the problems of historical depth in the study of cognition; the increase of many different disciplinary approaches; the resultant termino­logical confusion; the weaknesses of the natural sciences in terms of the philosophy of science; the corresponding weaknesses of the cognitive science of religion in terms of the philosophy of science; the need to replace strategic triumphalism on the one hand and strategic isolationism on the other with strategic sobriety; the need to maintain that the study of religion concerns origins, functions, forms, meanings and structures as well as texts; the realization that the methodological tools accompanying cognitive approaches should be handled with care and prudence; the reduction of cognition exclusively to processes in the brain ignores recent neurological research that points to alternative models of cognition; and there are many more possibilities in cognitive research than have been acknowledged by the pioneers of cognitive approaches to the study of religion. The article briefly discusses the many histories of research in cognition during the past 150 years and illustrates various cognitive themes which might be fruitfully pursued by scholars of religion.

William Croone’s theory of muscular contraction

1961 ◽  
Vol 16 (2) ◽  
pp. 158-178 ◽  
Keyword(s):  
Spinal Cord ◽  
Seventeenth Century ◽  
Muscle Contraction ◽  
Muscular Contraction ◽  
The Body ◽  
The Other ◽  
First Person ◽  
Muscular Movement ◽  
The One ◽  
The Brain

In the mid-seventeenth century William Croone had been the earliest among his contemporaries to concern himself with muscular motion. Thus, much of the discussion on muscular movement in the period after 1664 is either a commentary upon Croone’s views or is derived from them, and his influence was thus widespread, especially on the Continent. The background to Croone’s own views is largely that of Greek physiology as represented in the works of Galen. The first person who had a theory of muscle contraction seems to have been Erasistratus. Galen says that Erasistratus of Chios (fl. 290 b.c.) considered that when a muscle is filled with pneuma its breadth increases while its length diminishes and for this reason it is contracted. (1) Galen himself was impressed by the contractility of muscle and by the fact that this contractility depends on the nerve arising from the spinal cord and entering the muscle, where it branches repeatedly and sends its branches into all parts of the muscle. If the nerve, entering the muscle, be cut or injured or merely compressed the muscle loses all movement and sensitivity. (2) Galen considered that a muscle is made up of fibres and flesh. (3) The fibres of the muscle are continuous with those of its tendons at either end. In the body of the muscle itself the fibres are spread apart by the flesh contained in the interspaces between them. Each of these continuous fibres extending through both the tendon and the muscle Galen considers to be made up of finer fibres—on the one hand of inert and insensitive fibres of the same kind as occur in ligaments and, on the other hand, of sensitive fibres which are simply fine extensions of the branches of the nerves. (4) Galen does not, however, seem to offer, as does Erasistratus any mechanism to account for muscle contraction. To Galen the muscle is simply moved by the motor faculty which comes from the brain.

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