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David Strumfels
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Science / computing gourmet
Science / computing gourmet

363 followers
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The basal ganglia form a major brain system in all species of vertebrates, but in primates (including humans) there are special features that justify a separate consideration. As in other vertebrates, the primate basal ganglia can be divided into striatal, pallidal, nigral, and subthalamic components. In primates, however, there are two pallidal subdivisions called the external globus pallidus (GPe) and internal globus pallidus (GPi). Also in primates, the dorsal striatum is divided by a large tract called the internal capsule into two masses named the caudate nucleus and the putamen—in most other species no such division exists, and only the striatum as a whole is recognized. Beyond this, there is a complex circuitry of connections between the striatum and cortex that is specific to primates. This complexity reflects the difference in functioning of different cortical areas in the primate brain.
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The prisoner's dilemma is a standard example of a game analyzed in game theory that shows why two completely rational individuals might not cooperate, even if it appears that it is in their best interests to do so. It was originally framed by Merrill Flood and Melvin Dresher while working at RAND in 1950. Albert W. Tucker formalized the game with prison sentence rewards and named it "prisoner's dilemma", presenting it as follows:

Two members of a criminal gang are arrested and imprisoned. Each prisoner is in solitary confinement with no means of communicating with the other. The prosecutors lack sufficient evidence to convict the pair on the principal charge, but they have enough to convict both on a lesser charge. Simultaneously, the prosecutors offer each prisoner a bargain. Each prisoner is given the opportunity either to betray the other by testifying that the other committed the crime, or to cooperate with the other by remaining silent.
Prisoner's dilemma
Prisoner's dilemma
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In the philosophy of mind, collective intentionality characterizes the intentionality that occurs when two or more individuals undertake a task together. Examples include two individuals carrying a heavy table up a flight of stairs or dancing a tango.

This phenomenon is approached from psychological and normative perspectives, among others. Prominent philosophers working in the psychological manner are Raimo Tuomela, Kaarlo Miller, John R. Searle, and Michael E. Bratman. Margaret Gilbert takes a normative approach dealing specifically with group formation. David Velleman is also concerned with how groups are formed, but his account lacks the normative element present in Gilbert.

The notion that collectives are capable of forming intentions can be found, whether implicitly or explicitly, in literature going back thousands of years. For example, ancient texts such as Plato's Republic discuss the cooperative determination of laws and social order by the group composed of society as a whole. This theme was later expanded into social contract theory by Enlightenment-era philosophers such as Thomas Hobbes and John Locke. In the 20th century, the likes of Wilfrid Sellars and Anthony Quinton noted the existence of "We-Intentions" amid broader discussion of the concept of intentionality, and thus laid the groundwork for the focused philosophical analysis of collective intentionality that began in the late 1980s.
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John Rogers Searle (/sɜːrl/; born 31 July 1932) is an American philosopher. He is currently Willis S. and Marion Slusser Professor Emeritus of the Philosophy of Mind and Language and Professor of the Graduate School at the University of California, Berkeley. Widely noted for his contributions to the philosophy of language, philosophy of mind, and social philosophy, he began teaching at UC Berkeley in 1959.

As an undergraduate at the University of Wisconsin, Searle was secretary of "Students against Joseph McCarthy". He received all his university degrees, BA, MA, and DPhil, from the University of Oxford, where he held his first faculty positions. Later, at UC Berkeley, he became the first tenured professor to join the 1964–1965 Free Speech Movement. In the late 1980s, Searle challenged the restrictions of Berkeley's 1980 rent stabilization ordinance. Following what came to be known as the California Supreme Court's "Searle Decision" of 1990, Berkeley changed its rent control policy, leading to large rent increases between 1991 and 1994.

In 2000 Searle received the Jean Nicod Prize; in 2004, the National Humanities Medal; and in 2006, the Mind & Brain Prize. Searle's early work on speech acts, influenced by J. L. Austin and Ludwig Wittgenstein, helped establish his reputation. His notable concepts include the "Chinese room" argument against "strong" artificial intelligence. In March 2017, Searle was accused of sexual assault.
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Computer-aided detection (CADe), also called computer-aided diagnosis (CADx), are systems that assist doctors in the interpretation of medical images. Imaging techniques in X-ray, MRI, and ultrasound diagnostics yield a great deal of information that the radiologist or other medical professional has to analyze and evaluate comprehensively in a short time. CAD systems process digital images for typical appearances and to highlight conspicuous sections, such as possible diseases, in order to offer input to support a decision taken by the professional.
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Artificial intelligence, defined as intelligence exhibited by machines, has many applications in today's society. More specifically, it is Weak AI, the form of A.I. where programs are developed to perform specific tasks, that is being utilized for a wide range of activities including medical diagnosis, electronic trading, robot control, and remote sensing. AI has been used to develop and advance numerous fields and industries, including finance, healthcare, education, transportation, and more.
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Backpropagation is a method used in artificial neural networks to calculate a gradient that is needed in the calculation of the weights to be used in the network. Backpropagation is shorthand for "the backward propagation of errors," since an error is computed at the output and distributed backwards throughout the network’s layers. It is commonly used to train deep neural networks, a term referring to neural networks with more than one hidden layer.

Backpropagation is a special case of a more general technique called automatic differentiation. In the context of learning, backpropagation is commonly used by the gradient descent optimization algorithm to adjust the weight of neurons by calculating the gradient of the loss function.

Backpropagation requires the derivative of the loss function with respect to the network output to be known, which typically (but not necessarily) means that the desired target value is known. For this reason, it is considered to be a supervised learning method, although it is used in some unsupervised networks such as autoencoders. Backpropagation is also a generalization of the delta rule to multi-layered feedforward networks, made possible by using the chain rule to iteratively compute gradients for each layer. It is closely related to the Gauss–Newton algorithm and is part of continuing research in neural backpropagation. Backpropagation can be used with any gradient-based optimizer, such as L-BFGS or truncated Newton.
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Occupational therapy (OT) is the use of assessment and intervention to develop, recover, or maintain the meaningful activities, or occupations, of individuals, groups, or communities. It is an allied health profession performed by occupational therapists and Occupational Therapy Assistants. OTs often work with people with mental health problems, disabilities, injuries, or impairments.

The American Occupational Therapy Association defines an occupational therapist as someone who "helps people across the lifespan participate in the things they want and need to do through the therapeutic use of everyday activities (occupations). Common occupational therapy interventions include helping children with disabilities to participate fully in school and social situations, injury rehabilitation, and providing supports for older adults experiencing physical and cognitive changes."

Typically, occupational therapists are university-educated professionals and must pass a licensing exam to practice. Occupational therapists often work closely with professionals in physical therapy, speech therapy, audiology, nursing, social work, clinical psychology, and medicine.
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Phineas P. Gage (1823–1860) was an American railroad construction foreman remembered for his improbable survival of an accident in which a large iron rod was driven completely through his head, destroying much of his brain's left frontal lobe, and for that injury's reported effects on his personality and behavior over the remaining 12 years of his life‍—‌effects sufficiently profound (for a time at least) that friends saw him as "no longer Gage". 
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In psychology and neuroscience, executive dysfunction, or executive function deficit, is a disruption to the efficacy of the executive functions, which is a group of cognitive processes that regulate, control, and manage other cognitive processes. Executive dysfunction can refer to both neurocognitive deficits and behavioural symptoms. It is implicated in numerous psychopathologies and mental disorders, as well as short-term and long-term changes in non-clinical executive control.

Executive dysfunction is not the same as dysexecutive syndrome, a term coined by Alan Baddeley to describe a common pattern of dysfunction in executive functions, such as deficiencies in planning, abstract thinking, flexibility and behavioural control. This group of symptoms, usually resulting from brain damage, tend to occur together. However, the existence of dysexecutive syndrome is controversial.
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