Brain processes make sensations {sense, physiology}. Intensity is about amplitude, flux, and energy. Spatial location and extension are about size, shape, motion, number, and solidity. Time interval is about sequences, frequency, and before and after. Quality is about timbre.
physiology
Senses measure intensive quantities (pressure, temperature, concentration, sound, and light) using receptors that accumulate energy, an extensive quantity, on small surfaces over time intervals. Absorbed energy displaces mass and electric charge and becomes potential energy. Sense-cell altered-molecule potential energies can transfer energy to other molecules. Light-energy absorption changes retinal-receptor-molecule atom arrangements. Sound-energy absorption moves inner-ear hair-cell hairs and basilar membrane. Mechanical energy absorption stretches skin touch receptors. Heat energy absorption or loss moves cell receptor membrane in skin hot-or-cold receptor cells. Mechanical-energy absorption by smell and taste receptors bonds molecules to receptors and alters molecule atom arrangements.
Senses analyze signal-wave amplitude, phase, and frequency differences and ratios to make spatial, temporal, intensity, and frequency patterns. Information flows represent intensive quantities.
To detect, neurons can sum inputs to add and pass thresholds. To sum, neurons can take continued sums and so perform integration. To model physical interactions, neurons can adding logarithms to multiply. To find solutions, factors, probabilities, combinations, and permutations, neurons can sum logarithms to find continued products. To perform algebra and calculus operations, neuron assemblies calculate sums, differences, products, divisions, mu operations, differentials, integrals, exponentials, and logarithms. To perform geometric operations, neuron assemblies calculate rays, splines, lines, lengths, distances, angles, boundaries, areas, regions, region splits, region joins, volumes, triangulations, and trilateralizations. To use spaces, neuron assemblies detect coordinates, directions, coordinate origins, spatial positions, vectors, matrices, tensors, symmetries, and groups. To use objects, neuron assemblies detect self, not-self, patterns, features, objects, and object relations.
signals
Electrical signals can vary in amplitude, speed, frequency carried, rate, noise, sensitivity, threshold, attack and decay slope, phase, integration, dissemination, feedback, feedforward, control, querying, alternation, regulation, filtering, and tuning. Chemical signals can vary in type, concentration, diffusion, active transport, release, packet size, reactivity, and energy release.
signals: continuous/discrete
Brain has discrete neurons, neurotransmitter packets, nerve impulses, and molecules. Discrete processes can transfer and store information without degradation, perform logic operations, and represent categories.
Sense stimuli are discrete. Light is a photon stream. Sound is a phonon stream. Smells and tastes have individual molecule binding. Temperature and pressure are individual molecule movements. Receptors convert stimulus energy into ion and molecule motions. However, particles are small and many, and act on millisecond time scales. Over macroscopic space and time, stimuli appear continuous in intensity, spatial location and extension, time location and duration, and quality.
signals: vibrations
Touch receptors can detect mechanical vibrations up to 20 to 30 hertz, which are also the lowest frequency vibrations detected by hearing receptors. Below 20 Hz, people feel pressure changes as vibration, rather than hearing them as sound. Images flashed at 20-Hz rate begin to blend. 20-Hz is also maximum breathing, muscle-flexing, and harmonic-body-movement rate. Muscle contractions up to 20 times per second make "butterflies" in tummy, trembling with anger or fear, damping of depression, or excitations of joy. Animals can have spring-like devices that allow higher muscle-vibration rates.
effects
Sensations tend to cause reflex motor actions, which brain typically suppresses. Sensations excite and inhibit brain processes.
Sensations from voluntary muscles provide feedback after actions, for reward and punishment [Aristotle, -350].
measurement
Brain can measure relative and absolute distances, times, masses, and intensities. Measurements have accuracy, precision, reproducibility, selectivity, and sensitivity.
measurement: units
Mass, length, and time are fundamental measurements. During development, brain measures intensity ratios to build measurement units. Brains calculate distances using triangulation, linear perspective, and geometry [Staudt, 1847] [Veblen and Young, 1918]. Brain can detect distance difference of one degree arc. Brains can measure mass by linear or angular acceleration or by moment around axis, using combined sight and touch. Brain can detect mass difference of 100 grams. Perhaps, some neurons signal at millisecond and longer intervals to provide brain clocks for time measurement. Brain can detect time difference of 0.03 milliseconds.
measurement: accumulator
To measure extensive quantities, chemical or electrical accumulators can sum an intensive quantity sampled over time or space.
measurement: contrast
Neurons perceive relative intensity differences and intensity ratios. For example, eye receptors respond mainly to illumination changes, not to steady light. Receptors detect change over time. Receptor pairs detect differences over space.
processes
Perception factors stimuli into irreducible features, objects, and events.
processes: paths
Complex systems have enough parts, connections, and subsystems to have and regulate internal flows. Brain has a central flow and many other pathways and circuits. Central processing stream uses synchronized sequential signals, with feedback, feedforward, and other regulatory signals. Reticular activating system and brainstem start depolarization streams and so are basic to consciousness. Cerebrum constructs streams of consciousness.
processes: test signals
Like radar or sonar, brain scanning sends parallel signals through brain regions to obtain return-signal patterns.
processes: space
Neurons detect constants, variables, first derivatives, and second derivatives to determine distances and times and so create space and time, using extrapolation, interpolation, differentiation, integration, and optimization.
processes: motion minimization
Brain spatial and time coordinates minimize and simplify object motions, and number of objects to track, using fixed reference frames. Fixed reference frames make most object motions two-dimensional straight-line motions, which aid throwing and catching. In moving reference frames, more objects appear to move, and motions are three-dimensional curves.
processes: nulling
In size-weight illusions, mass discrimination seems to use nulling. Nulling can explain Weber-Fechner stimulus-sensation law.
processes: operations
Local sensory operations involve finding boundary, determining boundary orientation, increasing contrast, decreasing similarities, and detecting motion [Clarke, 1995]. Global sensory operations involve head and body movements, object trajectories, feature comparisons, and event sequences.
processes: resonation
To resonate, neuron pairs excite interneuron, which excites both neurons equally, while each paired neuron inhibits other paired neuron. If paired neurons fire asynchronously, interneuron signal has low amplitude and no frequency. If paired neurons fire synchronously, interneuron signal has high amplitude at input-signal frequency. Changing number of neurons and synapses traversed, or changing axon lengths, changes frequency.
Resonance detects synchronicity and so association. Interneurons can send resonating signals forward to other neurons.
processes: sampling
Body moves sense organs to sample different space regions over time. Directed movements gain information about critical features in critical locations at critical times. Birds and other animals move and then pause, every few seconds, to gather information [Matthews, 1973].
Perhaps, sampling uses attention mechanisms to decide to which location to move. Perhaps, sampling uses production systems to decide what to sample next. Perhaps, sampling uses template matching to recognize or categorize samples.
processes: statistics
Sense processing uses many neurons and so uses statistics.
processes: synchronization
Resting neurons send signals that adjust synapse properties and axon lengths, to coordinate timing among neuron sets. Synchronized signals lengthen or shorten pathways and quicken or slow synapses, to align time and space metrics.
processes: tensor
Sense-organ-receptor-, neuron-, and motor-neuron-array inputs are scalar or vector fields. Array uses a tensor function to transform field to output new vector field. Output vector field goes to cortical analysis or muscle and gland cells. Muscle cells contract in one direction with varying strength. Muscle-contraction vector fields have net contraction.
processes: timing
Brain neurons can send time signals at regular millisecond and/or longer intervals to act as clocks. Brain-timing-mechanism oscillation phases or periods can time perceptual events and body movements. At different times and positions, brain clocks run at different speeds for different purposes [Bair and Koch, 1996] [Bair, 1999] [Marsálek et al., 1997] [Nowak and Bullier, 1997] [Schmolesky et al., 1998].
Accumulation processes, such as adding energy units, can record time passage. Decay processes, subtracting energy units from total, can record time passage. Cycles can measure intervals between peaks. Tracking times requires processes that persist over time and whose later states causally depend on earlier states.
processes: wave modulation
Nerve signals can use wave-frequency modulation and wave-amplitude modulation to represent frequency and intensity.
processes: whole body
Brain, peripheral nervous system, and motor system interconnect, and sense qualities involve brain and body. For example, stroking skin can make people feel sense qualities in other body locations. Music and visual patterns can evoke whole body changes. Moods integrate senses, motor system, and body into overall feelings. Surprised people draw in breath and pull back, because drawing in breath helps one pull back, and body pulls away from what is in front.
speed
Brain processes sounds faster than sights. Brain processes colors faster than shapes. Action pathway is faster than object-recognition pathway. Brain calculates eye movements faster than voluntary movements [Revonsuo, 1999].
speed: information processing rate
Neuron information-processing rate is 40 bits per second. Ear information capacity is 10,000 bits per second. Eye can see 50 images per second, so eye information capacity is 500,000 to 600,000 bits per second.
Previous cell stimulation {adapting stimulus} reduces cell response {adaptation, sensation} {sensory adaptation} {sense adaptation}. Receptors have fewer biochemical reactions {receptor adaptation}, because cell has fewer energy storage molecules and cells make energy molecules slower than they use them. Receptors have lower cell-membrane potential gradients, because ions have flowed through membrane channels and active transport is slower than ion flow through open ion channels. After adapting stimulus ceases, cells increase sensitivity and responses.
Monitoring heart rate electronically {biofeedback}| allows learning voluntary heart-rate control.
Neurons can receive from two eye, ear, or other-sense neurons and detect time, space, or intensity differences. For two spatial positions, cells detect ear time difference {characteristic delay}, eye spatial difference, or smell, taste, or touch concentration or pressure difference.
Sense qualities {quality, sense} depend on opponent and categorization processes.
sum
ON-center neuron can add inputs from two neurons. Brightness depends on adding.
opponent processes
ON-center neuron can receive input from two neurons. Input from one neuron subtracts from input from other neuron. Human color vision uses such opponent processes. (Opponent-process opposites have same information as opponent process.)
continuous
Sum and opponent processes make continuous scales. For example, values can range from +1 to -1.
categorization
To divide ranges into intervals and make discrete categories, neurons use thresholds [Damper and Harnad, 2000]. Comparing different opponent processes can filter to make categories.
Stimuli tend to cause muscular or glandular responses. By attending to stimuli or responses, animals can learn to inhibit muscular or glandular responses, so signals only affect brain {response internalization}.
Brain can sense simultaneous stimuli at different times {sensory onset asynchrony} (SOA).
Perceptions have relative intensities {intensity, sense physiology} at locations.
coding
Axon-hillock membrane potential, axon current, average nerve-impulse rate, or neurotransmitter release can represent intensity.
receptors
Mechanical strains, temperature changes, chemical bonding, cell-hair vibration, and photon absorption change receptor membrane-molecule configurations. Configuration rearrangement changes molecule potential energy. Molecule steady-state configurations have lowest potential energy. Receptors transduce molecule potential-energy change into neurotransmitter-packet release at synapses onto neuron dendrites and cell bodies. Neurotransmitters open or close membrane ion channels to change synaptic neuron-membrane electric potential.
neurons
Synaptic membrane potentials spread to neuron axon hillock, where they add. Every millisecond, if hillock-membrane depolarization exceeds threshold, hillock membrane sends nerve impulse down axon.
threshold
Previous activity and neurohormones change neuron thresholds, so neurons detect current relative intensity, not absolute intensity. Perceptual intensities can be transient or sustained.
Small stimuli, such as gentle touch, can trigger sense response {irritability, sense}.
Sense receptors {sensory transducer} convert kinetic or potential energy from mechanical-force touch, temperature, and hearing translations and vibrations, or electrical-force light, liquids, or gases into cell-membrane depolarizations, whose electrical effects pass to neurons.
Machine computation is for stepwise analysis. Brain computation is for synthesis over time. Unlike computer programs, sensations can cause ongoing excitation {sustained response} at same location. Sustained responses are like steady states, not equilibrium states or transient states. Sustained responses use invariants and transformations to reach steady state. Neural assemblies have evolved to develop sustained responses. Sustained responses can serve as symbol grounds.
Objects have shape, texture, color, spatial location, distance, surface orientation, and motion. Brain processes object information in separate brain regions at different times and different processing speeds. Perception neural activities associate {binding} all feature and object information at all times [Domany et al., 1994] [Lisman and Idiart, 1995] [Malsburg, 1981] [Malsburg, 1995] [Malsburg, 1999] [Milner, 1974] [Robertson, 2003] [Treisman, 1996] [Treisman and Schmidt, 1982] [Treisman, 1998] [Tsal, 1989] [Wojciulik and Kanwisher, 1998] [Wolfe and Cave, 1999]. Color, shape, depth, motion, and orientation unify into objects and events [Treisman, 2003]. Same-spatial-location features associate. Simultaneous features associate.
attention
Binding typically requires attention. Perhaps, attention enhances attended-object brain processing. Simultaneous attention to features associates them. With minimum attention, adjacent-object property can bind to half-attended object. With no attention, non-conscious information processing can have perceptual binding [Treisman and Gelade, 1980].
short-term memory
Binding requires short-term memory, which holds all object features simultaneously. Short-term memory processing has EEG gamma waves. Perhaps, reverberating brain activity causes gamma waves. However, short-term memory involves more than synchronous or phasic firing [Tallon-Baudry and Bertrand, 1999].
brain processes
Perhaps, binding uses neuron labels, gene patterns, development patterns, frequently repeated experiences, space location, or time synchronization [Malsburg, 1999]. Learned associations link similar features.
Mammal superior colliculus can integrate same-spatial-location multisensory information, but reptiles use only separate sense processes [O'Regan and Noë, 2001]. Strongly firing cortical and thalamic neurons link temporarily. Medial-temporal-lobe system, especially hippocampus, is for binding. Visual-cortex neuron-assembly synchronous firing can represent object images [Engel and Singer, 2001] [Engel et al., 1991] [Engel et al., 1999] [Gray, 1999] [Gray et al., 1989] [Kreiter and Singer, 1996] [Laurent, 1999] [Laurent et al., 2001] [MacLeod et al., 1998] [Malsburg, 1981] [Malsburg, 1999] [Shadlen and Movshon, 1999] [Singer, 1999] [Singer, 2000] [Stopfer et al., 1997] [Thiele and Stoner, 2003]. Perhaps, master maps or central information exchanges synchronize topographic maps.
From one stimulus source, brain processes different feature types in separate brain regions, at different times and processing speeds. How does brain associate object features {binding problem}|? Perhaps, brains use common signals for all processes.
Moving spot triggers different motion detectors. How does brain associate two stimulus sources with one moving object {correspondence problem, binding}? Perhaps, brain follows spot from one location to next unambiguously.
Turning one spot on and off can trigger same motion detector. How does brain associate detector activation at different times with one spot? Perhaps, brain assumes same location is same object.
From many stimulus sources, brain processes different objects' feature types in separate brain regions, at different times and processing speeds. How do brains associate object features to objects {parsing problem}|? Perhaps, brains use common signals for processes.
Perhaps, background field {perceptual field} links perceptual locations, synchronizes times, and associates features to objects and events. During development, space and time correlations among sense features and motor movements build perceptual field. First, neurons note other-neuron states and store feature correlations. Next, neuron assemblies note other-neuron-assembly states and store object and movement correlations. Then, larger neuron assemblies work together to store scenes and stories [Desimone and Duncan, 1995] [Flohr, 2000] [Freeman, 1975] [Harris et al., 2003] [Hebb, 1949] [Palm, 1982] [Palm, 1990] [Rowland and Blumenthal, 1974] [Szentagothai and Arbib, 1975] [Varela et al., 2001].
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Date Modified: 2022.0225