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PubMed1995

Second-order neurones and receptor mechanisms in visual- and olfactory-information processing.

The retina and olfactory bulb are relatively simple in their synaptic operation, and provide insight into the fundamental synaptic mechanisms of brain functions. In the visual system, bipolar cells receive glutamate input from photoreceptors, and segregate visual inputs into parallel ON and OFF responses to light exposure and termination. In the olfactory system, the mitral and tufted cells respond to excitatory inputs from olfactory receptor neurones, and undergo reciprocal regulation through dendrodendritic synapses with their associated granule cells. Recent studies of the synaptic operation and regulation of the bipolar, mitral and tufted cells, at the molecular level, have revealed the detailed synaptic mechanisms of the second-order neurones in the segregation and discrimination of sensory information, as well as the modulatory synaptic mechanism that is involved in olfactory-recognition memory formation.

Animals↗
PubMed1976

[Possibilities for information processing and operations simplification in multidimensional tasks of morphokinetic synthesis].

The authors propose an iterative method for separating classes of objects by reduction of multidimentional space of sings, which describe objects by twodimentional space of two integral processings of the differences between sings. For this purpose the differences are evaluated by three steps rating: positive difference, negative difference and no difference. The proposed iterative algorhythm allows by finite and a small number of procedures to remove indeterminace which in the general case is contained in the so defined on the work integral processings. The application of the algorhythm does not require a special mathematical training. Represantation of the objects by integral characteristics is made in twodimentional space. In the paper the report the authors give a generalization for the case of M-steps rating for evaluation of the differences between the signs of the objects.

Information Theory↗
PubMed2006

Emotional and cognitive information processing in web-based medical education.

The patient-physician relationship can be conceived as a process of structuring an ill-structured emotional-cognitive problem. So, new methods should be developed in order to capture the relations among emotions and cognitions, and physicians should be educated to recognize the influence of emotions on medical decision-making. The paper describes GRASP, an e-learning application based upon the assumption that cognitions and emotions are dual concepts. The results of a blended e-learning experiment are shown. The students were confronted with a role-playing based illness narrative. Their observations were segmented into information units, and uploaded on the e-learning system DVLN. The set of information units was then transformed into a bipartite graph, and analysed by means of STRUCTURE, an application aimed at grasping the structure of the relations among a set of "objects". The results were compared with Correspondence Analysis. The implications for medical education, medical reasoning, and medical record design are discussed.

Cognition↗
PubMed1981

Comparison of information-processing capacities in young and aged subjects using reaction times.

Older subjects are compared to younger subjects on four reaction time tasks. Utilizing a model proposed by Teichner and Krebs (1974), four simple tasks were evolved to estimate: simple reaction time, response selection, stimulus-response translation, and stimulus-stimulus translation. Results indicated that the time difference found between the elderly and young subjects on a simple RT task was relatively equivalent to the time differences found on tasks isolating the components of response selection and stimulus-response translation. However, on a task necessitating a stimulus-stimulus translation the elderly showed a significantly greater increment in RT than found on the previous three tasks. It was concluded that the elderly have no relative difficulty making judgments in terms of the number of response choices and when the information for a judgment has direct relevance toi the response choice. When the information for a judgment does not have direct relevance to the response choice. When the information for a judgment does not have direct relevance to the decision, it is difficult for elderly persons to use this information adequately.

Adult↗
PubMed1979

The origin of life. A cybernetic and informational process.

According to the model presented in this paper, the beginning of life was marked by the coupling of two complementary nucleotide bases: adenine and thymine. The adenine-thymine system received photons from the sun and stored their energy in the form of a chemical high-energy bond between two phosphoric acid molecules, which were before-hand fixed by adenine from the aqueous environment. The energy of the high-energy bond was then delivered in the form of two waves of electronic excitation. These were utilized to synthesize new molecules, starting from the carbonic acid and ammonia molecules, fixed from the aqueous environment by the polar groups of the nucleotide bases. In this way, a nucleotides-histone protosystem (NHPS) was self-synthesized, evolving step by step towards complexity, by means of some internal cybernetic and informational mechanisms. During its evolution, the NHPS synthesized a limiting membrane, produced the organizing elements of the cellular organelles (chloroplastes, mitochondria, ribosomes etc) and constructed microtubules and microfilaments. Subsequently, the NHPS evolved to the building of DNA-histone system and formed the cellular nucleus.

Adenine↗
PubMed2005

Designing a framework of intelligent information processing for dentistry administration data.

OBJECTIVES: This study was designed to test a cumulative view of current data in the clinical database at the Faculty of Dentistry, Dalhousie University. We planned to examine associations among demographic factors and treatments. METHODS: Three tables were selected from the database of the faculty: patient, treatment and procedures. All fields and record numbers in each table were documented. Data was explored using SQL server and Visual Basic and then cleaned by removing incongruent fields. After transformation, a data warehouse was created. This was imported to SQL analysis services manager to create an OLAP (Online Analytic Process) cube. RESULTS: The multidimensional model used for access to data was created using a star schema. Treatment count was the measurement variable. Five dimensions--date, postal code, gender, age group and treatment categories--were used to detect associations. Another data warehouse of 8 tables (international tooth code # 1-8) was created and imported to SAS enterprise miner to complete data mining. Association nodes were used for each table to find sequential associations and minimum criteria were set to 2% of cases. Findings of this study confirmed most assumptions of treatment planning procedures. There were some small unexpected patterns of clinical interest. Further developments are recommended to create predictive models. CONCLUSIONS: Recent improvements in information technology offer numerous advantages for conversion of raw data from faculty databases to information and subsequently to knowledge. This knowledge can be used by decision makers, managers, and researchers to answer clinical questions, affect policy change and determine future research needs.

Adolescent↗
PubMedDate not supplied

[Cell molecular computer. IX. Coding principles in intracellular information processing].

Methods of coding the number and search for molecular program in a molecular computer are considered. The limited length of the nucleotide code is (see formula) where Pi -- probability of request of the given program, N -- total number of programs. Energetic expenditures for the synthesis of the code with the length l (in an ideal case without noise) E approximately 10 kT X l. Protein-nucleic recognition allows the work of the cell with almost the same expenditures on the account of Brown search in the presence of noise.

Cells↗
PubMed2003

The evolution of concepts of vestibular peripheral information processing: toward the dynamic, adaptive, parallel processing macular model.

In a letter to Robert Hooke, written on 5 February, 1675, Isaac Newton wrote "If I have seen further than certain other men it is by standing upon the shoulders of giants." In his context, Newton was referring to the work of Galileo and Kepler, who preceded him. However, every field has its own giants, those men and women who went before us and, often with few tools at their disposal, uncovered the facts that enabled later researchers to advance knowledge in a particular area. This review traces the history of the evolution of views from early giants in the field of vestibular research to modern concepts of vestibular organ organization and function. Emphasis will be placed on the mammalian maculae as peripheral processors of linear accelerations acting on the head. This review shows that early, correct findings were sometimes unfortunately disregarded, impeding later investigations into the structure and function of the vestibular organs. The central themes are that the macular organs are highly complex, dynamic, adaptive, distributed parallel processors of information, and that historical references can help us to understand our own place in advancing knowledge about their complicated structure and functions.

Acoustic Maculae↗
PubMed1994

Parallel information processing in the water maze: evidence for independent memory systems involving dorsal striatum and hippocampus.

This experiment investigated the ability of rats with dorsal striatal or fornix damage to learn the location of a visible platform in a water maze. We also assessed the animals' ability to find the platform when it was hidden (submerged). Rats with neurotoxic damage to the dorsal striatum acquired both the visible and hidden platform versions of the task, but when required to choose between the spatial location they had learned and the visible platform in a new location they swam first to the old spatial location. Rats with radio-frequency damage to the fornix acquired the visible platform version of the water maze task but failed to learn about the platform's location in space. When the visible platform was moved to a new location they swam directly to it. Normal rats acquired both the visible and hidden platform versions of the task. These findings suggest that in the absence of a functional neural system that includes dorsal striatum, spatial information predominantly controlled behavior even in the presence of a cue that the animals had previously been reinforced for approaching. In the absence of a functional hippocampal system behavior was not affected by spatial information and responding to local reinforced cues was enhanced. The results support the idea that different neural substrates in the mammalian nervous system acquire different types of information simultaneously and in parallel.

Animals↗
PubMed2003

Disruption of information processing in the supplementary motor area of the MPTP-treated monkey: a clue to the pathophysiology of akinesia?

It has been suggested that the underactivity of mesial frontal structures induced by dopamine depletion could constitute one of the main substrates underlying akinesia in Parkinson's disease. Functional imaging and movement-related potential recordings indicate an implication of the frontal lobes in this pathological process, but the question has not yet been investigated at a cellular level using single unit recording. We therefore compared neuronal activity in both the presupplementary motor area (pre-SMA) and the supplementary motor area proper (SMAp) of the Macaca mulatta monkey during a delayed motor task, before and after MPTP treatment. In the pre-SMA, which receives strong inputs from the prefrontal cortex, the baseline firing frequency and the percentage of neurons responding to visual instruction cues decreased in lesioned monkeys. In the SMAp, which sends direct outputs to the primary motor cortex, not only was the response to visual cues impaired, but the percentage of SMAp neurons responding to intracortical microstimulation fell and the threshold of response rose. Neuronal activity after the Go signal diminished sharply in both structures in the symptomatic animal and the discharge pattern became more irregular; in the SMAp neuronal activity remained modified longer. Most of these changes could already be observed in the presymptomatic animal presenting no clinical signs of parkinsonism. These data would indicate that, at the moment when dopamine depletion has impaired the ability of cortical neurons to operate the focused selection of incoming information giving instructions for movement, pre-SMA and SMAp neurons are also in a state of severe hypoactivity. The conjunction of these phenomena could play a critical role in the genesis of akinesia.

Animals↗
PubMed1977

Information processing along the course of a visual interneuron.

Locust ocellar retinal cells are innervated by giant second order cells, 2 mm long, which show discrete zones of integration along their course, including a major zone in the axonal length of the neuron. The complex synaptic arrangements which exist between higher-order afferent and efferent cells and these second order cells along their course suggests that transmission takes place by the electrotonic spread of slow potentials. The size and accessibility of these visual interneurons offers a unique preparation for examining mechanisms of graded synaptic transmission.

Action Potentials↗
PubMed2003

Synthesis and spectral investigations of a new dyad with spiropyran and fluorescein units: toward information processing at the single molecular level.

A new dyad 1 with two spiropyran units as the photochromic acceptors and one fluorescein unit as the fluorescent donor was synthesized and characterized. External inputs (ultraviolet light, visible light, and proton) induce the reversible changes of the structure and, concomitantly, the absorption spectrum of dyad 1 due to the presence of two spiropyran units. Only the absorption spectrum of the ME form of the spiropyran units in dyad 1 has large spectral overlap with the fluorescence spectrum of the fluorescein unit. Thus, the fluorescence intensity of dyad 1 is modulated by reversible conversion among the three states of the photochromic spiropyran units and the fluorescence resonance energy transfer (FRET) between the ME form and the fluorescein unit. Based on the fact that dyad 1 could "read out" three external input signals (ultraviolet light, visible ligh,t and proton) and "write" a compatible specific output signal (fluorescence intensity), dyad 1 described here can be considered to perform an integrated circuit function with one OR and one AND interconnected logic gates. The present results demonstrate an efficient strategy for elaborating and transmitting information at the single molecular level.

Journal Article↗
PubMedDate not supplied

[The role of the electromechanical and reaction-diffusion system of intraneuronal information processing in brain function].

The experimental data of previous papers are considered as a basis for the hypothesis about intraneuronal system controlled by cyclic nucleotides and changing the membrane permeability upon creating the generatory potential. This system is suggested to be an extremal molecular regulator in which the price of action per single operation approximates the physical limit. The electro-mechanical intraneuronal system is capable of solving multidimensional physical problems by means of molecular "digital" hypersound holo-gram coded by DNA molecular text which is an image of functions of target search.

Animals↗
PubMed1984

An information-processing analysis of children's accuracy in predicting the appearance of rotated stimuli.

Children's ability to discriminate reflections and rotations of visual stimuli was examined using a kinetic imagery task. It was hypothesized that success would be related to the number and placement of orientation markers on the stimuli, as well as whether or not reflections had to be discriminated from simple rotations. 40 4- and 5-year-old children were directed to imagine how a stimulus would look if rotated to a specified location and asked to indicate the appearance of the reoriented stimulus by selecting the correct option from a number of foils. 48 of the items required only discrimination of a reoriented stimulus. The other 48 also required discrimination of a reflection of the reoriented stimulus. Stimuli differed in the number of orientation cues on the edges of the figures. Results revealed that prediction accuracy was associated with the existence of orientation markers on the stimuli, as well as age, sex, type of discrimination, and several interactions among the variables. Findings were discussed in comparison to a priori predictions based on an analysis of how children might use orientation information when performing mental rotation tasks.

Child Development↗
PubMed1988

Two forms of persistence in visual information processing.

Iconic memory, which was initially regarded as a unitary phenomenon, has since been subdivided into several components. In the present work we examined the joint effects of two such components (visible persistence and the visual analog representation) on performance in a partial report task. The display consisted of 15 alphabetic characters arranged around the perimeter of an imaginary circle on the face of an oscilloscope. The observer named the character singled out by a bar-probe. Two factors were varied: exposure duration of the array (10, 50, 100, 150, 200, 300, 400 or 500 ms) and duration of blank period (interstimulus interval, ISI) between the termination of the array and the onset of the probe (0, 50, 100, 150, or 200 ms). Performance was progressively impaired as both exposure duration and ISI were increased. The results were explained in terms of a probabilistic combinatorial model in which the timecourses of visible persistence and of the visual analog representation are regarded as time-locked to the onset and to the end of stimulation, respectively. The impairing effect of exposure duration was attributed to the relatively high spatial demands of the task that could be met optimally by information in visible persistence (which declines as a function of exposure duration), but less adequately by information in the visual analog representation. A second experiment, employing a task with lesser spatial demands, confirmed this interpretation.

Afterimage↗
PubMed2005

Post-choice information processing by pigeons.

In a conditional discrimination (matching-to-sample), a sample is followed by two comparison stimuli, one of which is correct, depending on the sample. Evidence from previous research suggests that if the stimulus display is maintained following an incorrect response (the so-called penalty-time procedure), acquisition by pigeons is facilitated. The present research tested the hypothesis that the penalty-time procedure allows the pigeons to review and learn from the maintained stimulus display following an incorrect choice. It did so by including a penalty-time group for which, following an incorrect choice, the sample changed to match the incorrect comparison, thus providing the pigeons with post-choice 'misinformation.' This misinformation group acquired the matching task significantly slower than the standard penalty-time group (that had no change in the sample following an error). Furthermore, acquisition of matching by a control group that received no penalty time fell midway between the other two groups, suggesting that the pigeons did not merely take more care in making choices because of the aversiveness of penalty-time. Thus, it appears that in the acquisition of matching-to-sample, when the stimulus display is maintained following an incorrect choice, the pigeons can review or acquire information from the display. This is the first time that such an effect has been reported for a nonhuman species.

Animals↗
PubMed1994

Information processing within the motor cortex. I. Responses of morphologically identified motor cortical cells to stimulation of the somatosensory cortex.

Inputs from the somatosensory cortex to the motor cortex have been proposed to function in learning of motor skills. In an attempt to analyze how these somatosensory inputs were processed in the motor cortex, neurons in the superficial layer of the cat motor cortex were classified into three groups on the basis of synaptic responses elicited by intracortical microstimulation (ICMS) of area 2. ICMS was delivered through seven electrodes implanted in area 2. When ICMS through one of the seven sites produced a response that was greater than 50% of the response produced by stimulating the seven sites at a time, the site was called a "dominant" site. Type I cells were those that had a dominant stimulation site and showed a constant response latency when examined by a double shock test. Type II cells were those that had a dominant site but displayed a variable latency. Type III cells had no dominant site and showed a variable latency. Latency of type I responses was 1.2-2.6 milliseconds, which was much shorter than that of type II and type III responses. Seventy-nine neurons in layers II/III of the motor cortex, which responded to ICMS in area 2, were stained by intracellular injection of biocytin. From the presence of an apical dendrite and rich spines on the dendrites, 23 type I, 21 type II, and 15 type III cells were classified as pyramidal cells. Type II pyramidal cells were located more superficially than type I and type III pyramidal cells. On the basis of the absence or sparseness of dendritic spines, three type I and four type II cells in layers II/III were classified as nonpyramidal cells. These cells consisted of five small multipolar cells in layer II and a large multipolar cell and a small bitufted cell in layer III. The remaining 11 cells were not classified because of insufficient staining. Since type I and type II cells are considered to represent monosynaptic and polysynaptic responses to stimulation of area 2, respectively, information flow from type I cells to more superficially located type II cells is presumed in layers II/III of the motor cortex. Type III responses suggest the presence of a convergent flow of impulses inside of and/or between areas 2 and 4.

Animals↗
PubMed1998

Exaptation and torsion: toward a theory of natural information processing.

Several conundrums are provoked by attempts to provide algorithmic descriptions of natural phenomena. A characteristic feature of natural computation is a breakdown in the formal simulation relation. This is called hermeneutic torsion, and is formally the failure to commute of a diagram describing homomorphisms between dynamical systems. This torsion is a source of computational power. For example, it is deeply involved with phenomena such as exaptation, wherein an existing structure is recruited for a novel function. Exaptation occurs continually at the macromolecular level and is fundamentally nonalgorithmic; our system-theoretic models of computation deal with structural descriptions for which a functional semantics must be assigned in advance, and a natural system continually 'diagonalizes out' of this semantics. This perspective clarifies the nature of computing power and encourages consideration of a new kind of transcomputational complexity.

Algorithms↗