Neuron-Specific Response Characteristics Predict the Magnitude of Multisensory Integration

2003 ◽  
Vol 90 (6) ◽  
pp. 4022-4026 ◽  
Author(s):  
Thomas J. Perrault ◽  
J. William Vaughan ◽  
Barry E. Stein ◽  
Mark T. Wallace
Keyword(s):  
Spontaneous Activity ◽  
Multisensory Integration ◽  
Neuronal Response ◽  
Full Range ◽  
Specific Response ◽  
Multisensory Interaction ◽  
Response Characteristics ◽  
Response Profile ◽  
Sensory Responses ◽  
Stimulus Effectiveness

Multisensory neurons in the superior colliculus (SC) typically respond to combinations of stimuli from multiple modalities with enhancements and/or depressions in their activity. Although such changes in response have been shown to follow a predictive set of integrative principles, these principles fail to completely account for the full range of interactions seen throughout the SC population. In an effort to better define this variability, we sought to determine if there were additional features of the neuronal response profile that were predictive of the magnitude of the multisensory interaction. To do this, we recorded from 109 visual-auditory SC neurons while systematically manipulating stimulus intensity. Along with the previously described roles of space, time, and stimulus effectiveness, two features of a neuron's response profile were found to offer predictive value as to the magnitude of the multisensory interaction: spontaneous activity and the level of sensory responsiveness. Multisensory neurons with little or no spontaneous activity and weak sensory responses had the capacity to exhibit large response enhancements. Conversely, neurons with modest spontaneous activity and robust sensory responses exhibited relatively small response enhancements. Together, these results provide a better view into multisensory integration, and suggest substantial heterogeneity in the integrative characteristics of the multisensory SC population.

Gating of sensory responses of descending brain neurones during walking in crickets

1998 ◽  
Vol 201 (4) ◽  
pp. 559-572 ◽  
Author(s):  
E Staudacher ◽  
K Schildberger
Keyword(s):  
Sensory Processing ◽  
Neuronal Response ◽  
Acoustic Stimulus ◽  
Open Loop ◽  
Calling Song ◽  
Significant Information ◽  
Response Characteristics ◽  
Acoustic Stimuli ◽  
Walking Activity ◽  
Sensory Responses

Single descending brain neurones were recorded and stained intracellularly in the neck connectives of crickets while they walked upon a styrofoam ball under open-loop conditions. The animal's translational and rotational velocities were measured simultaneously, and various stimuli were used to investigate the neuronal response characteristics. Stimulation with a moving grating or an artificial calling song of 5 kHz induced optomotor behaviour and positive phonotaxis. An acoustic stimulus of 20 kHz elicited negative phonotaxis. <P> We report the first clear evidence for behaviourally dependent gating of sensory responses of identified descending brain neurones. Most descending cells only responded to visual stimuli or to an artificial calling song of 5 kHz while the animal was walking, indicating that the responses to these stimuli were gated by the walking activity of the animal. In contrast to this, responses to stimuli that elicit negative phonotaxis, such as acoustic stimuli of 20 kHz, were not gated. This indicates that the gating of sensory responses in these cells depends on the behavioural context of the stimulus. <P> From these findings, we conclude that significant information about the properties of sensory processing in higher-order neurones can only be gained from tests in behaviourally relevant paradigms. Important characteristics might otherwise be missed, thus leading to misinterpretations regarding their function. <P>

Quantitative characterization and spinal pathway mediating inhibition of spinal nociceptive transmission from the lateral reticular nucleus in the rat

1988 ◽  
Vol 59 (1) ◽  
pp. 226-247 ◽  
Author(s):  
A. J. Janss ◽  
G. F. Gebhart
Keyword(s):  
Electrical Stimulation ◽  
Spontaneous Activity ◽  
Pulse Duration ◽  
Neuronal Response ◽  
Response Threshold ◽  
Reticular Nucleus ◽  
Lateral Reticular Nucleus ◽  
Descending Inhibition ◽  
Nociceptive Transmission ◽  
Spinal Pathway

1. The modulation of spinal nociceptive transmission from the lateral reticular nucleus (LRN) was characterized for 47 spinal dorsal horn neurons in pentobarbital-anesthetized, paralyzed rats. All 47 units studied had receptive fields confined to the glabrous skin of the plantar surface of the ipsilateral hind foot and responded to mechanical stimulation as well as noxious heating (50 degrees C). Rostral projections contained in the ventrolateral quadrant of the cervical spinal cord were demonstrated for 15 of the 47 units by antidromic invasion. Glutamate- and stimulation-produced descending inhibition, the spinal pathway, and tonic descending inhibition from the LRN were systematically examined. 2. Inhibition of unit responses to heating of the skin by electrical stimulation in the LRN varied with the intensity, pulse duration (100 or 400 microseconds), and frequency (25–100 Hz) of stimulation. Greater inhibition was produced at lower intensities of stimulation with the 400-microseconds pulse duration and a frequency of 100 Hz. The effects of stimulation on spontaneous activity and responses to heat were compared in 16 experiments; inhibition of spontaneous activity was intensity dependent and did not differ significantly in magnitude from stimulation-produced inhibition of responses to heating of the skin. 3. Tracking experiments established that stimulation in the ipsilateral and contralateral ventrolateral medulla reliably attenuated unit responses to noxious heating of the skin and that stimulation in the LRN produced maximal inhibition at a low intensity of stimulation. Descending inhibition was quantitatively characterized from sites within (n = 32) and outside (n = 30) the LRN. Both the extrapolated mean stimulation threshold for inhibition and mean intensity inhibiting unit responses to heat to 50% of control were significantly lower for sites in the LRN. 4. The responses of seven spinal units to graded noxious heating of the skin were studied; all exhibited linear monotonic stimulus-response functions (SRFs) throughout the temperature range examined (42–50 degrees C). Electrical stimulation in the LRN significantly decreased the slope (42 +/- 4% of control) of the SRFs and increased the neuronal response threshold (2.0 +/- 0.7 degrees C). 5. S-glutamate (50 nmol, 0.5 microliter) was microinjected into stimulation sites within (n = 15) and distant from (n = 6) the LRN. Glutamate produced a transient (less than 7 min) but significant attenuation of neuronal responses to heat to 35 +/- 6% of control only when microinjected into the LRN.(ABSTRACT TRUNCATED AT 400 WORDS)

Real-Time Seismic Monitoring of the New Cape Girardeau Bridge and Preliminary Analyses of Recorded Data: An Overview

2006 ◽  
Vol 22 (3) ◽  
pp. 609-630 ◽  
Author(s):  
Mehmet Çelebi
Keyword(s):  
Real Time ◽  
Monitoring System ◽  
Mississippi River ◽  
Free Field ◽  
Seismic Monitoring ◽  
Ambient Vibration ◽  
Design Parameters ◽  
Specific Response ◽  
Response Characteristics ◽  
Broadband Network

This paper introduces the state-of-the-art seismic monitoring system implemented for the 1,206-m-long (3,956 ft) cable-stayed Bill Emerson Memorial Bridge in Cape Girardeau (Missouri), a new Mississippi River crossing, approximately 80 km from the epicentral region of the 1811 and 1812 New Madrid earthquakes. The real-time seismic monitoring system for the bridge includes a broadband network consisting of superstructure and free-field arrays and comprises a total of 84 channels of accelerometers deployed on the superstructure (towers and deck), pier foundations (caisson tops and bents), and in the vicinity of the bridge (e.g., free-field, both surface and downhole). The paper also introduces the high-quality response data obtained from the broadband network that otherwise would not have been possible with older instruments. Such data is aimed to be used by the owner, researchers, and engineers to (1) assess the performance of the bridge, (2) check design parameters, including the comparison of dynamic characteristics with actual response, and (3) better design future similar bridges. Preliminary spectral analyses of low-amplitude ambient vibration data and that from a small earthquake reveal specific response characteristics of this new bridge and the free-field in its proximity. There is coherent tower-cable-deck interaction that sometimes results in amplified ambient motions. Also, while the motions at the lowest (triaxial) downhole accelerometers on both Missouri and Illinois sides are practically free from any feedback of motions of the bridge, the motions at the middle downhole and surface accelerometers are influenced significantly even by amplified ambient motions of the bridge.

An Assessment of Response-Surfaces for Estimation of Fatigue Damage and Extreme Response Due to Environmental Loads

2003 ◽  
Author(s):  
Bernt J. Leira ◽  
Tore Holma˚s ◽  
Kjell Herfjord
Keyword(s):  
Fatigue Damage ◽  
Environmental Parameters ◽  
Response Surfaces ◽  
Specific Response ◽  
Statistical Distributions ◽  
Marine Structures ◽  
Environmental Loads ◽  
Response Characteristics ◽  
Polynomial Coefficients ◽  
Extreme Response

For marine structures subjected to environmental loads (i.e. waves, current, wind), the fatigue damage and long-term response characteristics can frequenlty expressed in terms of the environmental parameters by polynomial response surfaces. For both types of “response”, an integration across the range of variation for all the environmental parameters is required. The location of the intervals which give rise to the dominant contribution to these integrals is studied. Convergence studies are performed by applying response surfaces of increasing order, from linear to cubic expressions. In addition, response surfaces with lower cut-off limits at specific values for the environmental parameters are also investigated. Having obtained general expressions on non-dimensional form, various examples which correspond to specific response quantities for marine structures are considered. Typical values for the polynomial coefficients, and for the statistical distributions representing the environmental parameters, are applied. Convergence studies are subsequently performed for the particular example response quantities which are considered in order to make comparison with the general formulation. For the extreme response, the application of “extreme contours” obtained from the statistical distributions of the environmental parameters in combination with the response surface is explored.

Intermittent stimulus presentation stabilizes neuronal responses in macaque area MT

2012 ◽  
Vol 108 (8) ◽  
pp. 2101-2114 ◽  
Author(s):  
P. Christiaan Klink ◽  
Anna Oleksiak ◽  
Martin J. M. Lankheet ◽  
Richard J. A. van Wezel
Keyword(s):  
Neuronal Response ◽  
Stimulus Presentation ◽  
Sensory Stimulation ◽  
Response Variability ◽  
Spike Timing ◽  
Response Magnitude ◽  
General Effect ◽  
Neuronal Responses ◽  
Area Mt ◽  
Response Characteristics

Repeated stimulation impacts neuronal responses. Here we show how response characteristics of sensory neurons in macaque visual cortex are influenced by the duration of the interruptions during intermittent stimulus presentation. Besides effects on response magnitude consistent with neuronal adaptation, the response variability was also systematically influenced. Spike rate variability in motion-sensitive area MT decreased when interruption durations were systematically increased from 250 to 2,000 ms. Activity fluctuations between subsequent trials and Fano factors over full response sequences were both lower with longer interruptions, while spike timing patterns became more regular. These variability changes partially depended on the response magnitude, but another significant effect that was uncorrelated with adaptation-induced changes in response magnitude was also present. Reduced response variability was furthermore accompanied by changes in spike-field coherence, pointing to the possibility that reduced spiking variability results from interactions in the local cortical network. While neuronal response stabilization may be a general effect of repeated sensory stimulation, we discuss its potential link with the phenomenon of perceptual stabilization of ambiguous stimuli as a result of interrupted presentation.

The Development of Multisensory Integration in the Brain

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 35-35 ◽  
Author(s):  
M T Wallace
Keyword(s):  
Multisensory Integration ◽  
Time Course ◽  
Receptive Fields ◽  
Developmental Time ◽  
Response Latencies ◽  
Sensory Stimuli ◽  
Sensory Inputs ◽  
Response Enhancement ◽  
Sensory Responses ◽  
The Brain

Multisensory integration in the superior colliculus (SC) of the cat requires a protracted postnatal developmental time course. Kittens 3 – 135 days postnatal (dpn) were examined and the first neuron capable of responding to two different sensory inputs (auditory and somatosensory) was not seen until 12 dpn. Visually responsive multisensory neurons were not encountered until 20 dpn. These early multisensory neurons responded weakly to sensory stimuli, had long response latencies, large receptive fields, and poorly developed response selectivities. Most striking, however, was their inability to integrate cross-modality cues in order to produce the significant response enhancement or depression characteristic of these neurons in adults. The incidence of multisensory neurons increased gradually over the next 10 – 12 weeks. During this period, sensory responses became more robust, latencies shortened, receptive fields decreased in size, and unimodal selectivities matured. The first neurons capable of cross-modality integration were seen at 28 dpn. For the following two months, the incidence of such integrative neurons rose gradually until adult-like values were achieved. Surprisingly, however, as soon as a multisensory neuron exhibited this capacity, most of its integrative features were indistinguishable from those in adults. Given what is known about the requirements for multisensory integration in adult animals, this observation suggests that the appearance of multisensory integration reflects the onset of functional corticotectal inputs.

Other Sensory Responses and Multisensory Interactions

2017 ◽  
pp. 242-251
Author(s):  
Riitta Hari ◽  
Aina Puce
Keyword(s):  
Direct Access ◽  
Evoked Responses ◽  
Correct Interpretation ◽  
Multisensory Interaction ◽  
Olfactory Stimuli ◽  
Multisensory Interactions ◽  
Stimulating Electrodes ◽  
Sensory Responses ◽  
Events Detection ◽  
The Brain

This chapter discusses olfactory and visceral responses as well as the MEG/EEG signature of multisensory interaction. Olfactory stimuli can be embedded in a continuous humified airflow where the stimuli are presented at intervals of tens of seconds to avoid short-term habituation. Visceral stimulation typically requires purpose-built stimulating electrodes for direct access to the viscera. Studies of multisensory interaction are necessary because our everyday experiences involve inputs from multiple senses, the temporal coincidence of which allows the brain to construct representations of unique objects or events. Detection and correct interpretation of the nonlinear multisensory interactions call for careful considerations of both the sites of interaction and the changes in the amplitudes of evoked responses and spontaneous activity.

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