We have designed and fabricated a VLSI synapse that can learn a conditional probability or correlation between spike-based inputs and feedback signals. The synapse is low power, compact, provides nonvolatile weight storage, and can perform simultaneous multiplication and adaptation. We can calibrate arrays of synapses to ensure uniform adaptation characteristics. Finally, adaptation in our syna...

Synapses are a critical element of biologically-realistic, spike-based neural computation, serving the role of communication, computation, and modification. Many different circuit implementations of synapse function exist with different computational goals in mind. In this paper we describe a new CMOS synapse design that separately controls quiescent leak current, synaptic gain, and time-consta...

The effects of androgen on the density of spine synapses on pyramidal neurons in the CA1 area of the hippocampus were studied in ovariectomized (OVX) adult female rats. Treatment of OVX rats with testosterone propionate (TP; 500 microg/d, s.c., 2 d) significantly increased spine synapse density (from 0.661 +/- 0.016 spine synapse/microm3 in OVX rats to 1.081 +/- 0.018 spine synapse/microm3 afte...

Synaptic depression is a common form of short-term plasticity in the central and peripheral nervous systems. We show that in a network of two reciprocally connected neurons a single depressing synapse can produce two distinct oscillatory regimes. These distinct periodic behaviors can be studied by varying the maximal conductance, ḡinh, of the depressing synapse. For small ḡinh, the network has ...

QRISTAL is a commercial question answering system making intensive use of natural language processing both for indexing documents and extracting answers. It ranked first in the EQueR evaluation campaign (Evalda, Technolangue [1]) and in CLEF 2005 [8] and CLEF 2006 [6] for monolingual task (French-French) and multilingual task (English-French and Portuguese-French). This year Synapse Développeme...

Abstract By integrating sensing, memory and processing functionalities, biological nervous systems are energy area efficient. Emulating such capabilities in artificial is, however, challenging is limited by the device heterogeneity of sensing cores. Here we report an organic electrochemical transistor capable processing. The has a vertical traverse architecture crystalline–amorphous channel tha...

Brain-like computing is an important direction for the development of integrated circuits in post-Moore era, and artificial synaptic devices that can simulate ideal behavior key to building brainlike chips with neuron-synapse-neuron connectivity. Ferroelectric thin film materials have unique nonvolatile polarization, plasticity polarization very similar biological synapses, so ferroelectric bee...

QRISTAL [9] is a question answering system making intensive use of natural language processing both for indexing documents and extracting answers. It ranked first in the EQueR evaluation campaign (Evalda, Technolangue [3]) and in CLEF 2005 for monolingual task (French­French) and multilingual task (English­French and Portuguese­French). This article describes the improvements of the system sinc...

Neuronal development is characterized by a period of exuberant synaptic growth that is well studied. However, the mechanisms that restrict this process are less clear. Here we demonstrate that glycosylphosphatidylinositol-anchored cell-surface receptors of the Nogo Receptor family (NgR1, NgR2, and NgR3) restrict excitatory synapse formation. Loss of any one of the NgRs results in an increase in...