Apparent Duration as a Function of Intensity of Vibrotactile Stimulation

1969 ◽  
Vol 28 (1) ◽  
pp. 151-156 ◽  
Author(s):  
Goesta Ekman ◽  
Marianne Frankenhaeuser ◽  
Birgitta Berglund ◽  
Michael Waszak
Keyword(s):  
Electrical Stimulation ◽  
Stimulus Intensity ◽  
Index Finger ◽  
Left Index Finger ◽  
Estimation Technique ◽  
Logarithmic Function ◽  
Vibrotactile Stimulation ◽  
Apparent Duration ◽  
Fixed Standard ◽  
Stimulation Of

8 Ss were exposed to vibrotactile stimulation of 250 Hz, applied to the tip of the left index finger. Seven stimulus intensities, ranging from 26 to 48 db, were each combined with three stimulus durations, 50, 250, and 1200 msec. A magnitude-estimation technique with fixed standard was employed to obtain scale values of the apparent duration of each stimulus. The results indicate that apparent duration can be described as a logarithmic function of stimulus intensity. This conclusion is in line with our previous findings concerning apparent duration of electrical stimulation.

Functional magnetic resonance imaging of somatosensory cortex activity produced by electrical stimulation of the median nerve or tactile stimulation of the index finger

2000 ◽  
Vol 93 (5) ◽  
pp. 774-783 ◽  
Author(s):  
Maxwell Boakye ◽  
Sean C. Huckins ◽  
Nikolaus M. Szeverenyi ◽  
Bobby I. Taskey ◽  
Charles J. Hodge
Keyword(s):  
Electrical Stimulation ◽  
Median Nerve ◽  
Somatosensory Cortex ◽  
Tactile Stimulation ◽  
Index Finger ◽  
Functional Magnetic Resonance ◽  
Content Type ◽  
The Right ◽  
Fine Print ◽  
Stimulation Of

Object. Functional magnetic resonance (fMR) imaging was used to determine patterns of cerebral blood flow changes in the somatosensory cortex that result from median nerve stimulation (MNS).Methods. Ten healthy volunteers underwent stimulation of the right median nerve at frequencies of 5.1 Hz (five volunteers) and 50 Hz (five volunteers). The left median nerve was stimulated at frequencies of 5.1 Hz (two volunteers) and 50 Hz (five volunteers). Tactile stimulation (with a soft brush) of the right index finger was also applied (three volunteers). Functional MR imaging data were transformed into Talairach space coordinates and averaged by group. Results showed significant activation (p < 0.001) in the following regions: primary sensorimotor cortex (SMI), secondary somatosensory cortex (SII), parietal operculum, insula, frontal cortex, supplementary motor area, and posterior parietal cortices (Brodmann's Areas 7 and 40). Further analysis revealed no statistically significant difference (p > 0.05) between volumes of cortical activation in the SMI or SII resulting from electrical stimuli at 5.1 Hz and 50 Hz. There existed no significant differences (p > 0.05) in cortical activity in either the SMI or SII resulting from either left- or right-sided MNS. With the exception of the frontal cortex, areas of cortical activity in response to tactile stimulation were anatomically identical to those regions activated by electrical stimulation. In the SMI and SII, activation resulting from tactile stimulation was not significantly different (p > 0.05) from that resulting from electrical stimulation.Conclusions. Electrical stimulation of the median nerve is a reproducible and effective means of activating multiple somatosensory cortical areas, and fMR imaging can be used to investigate the complex network that exists between these areas.

Swallowing and upper esophageal sphincter contraction with transcranial magnetic-induced electrical stimulation

1993 ◽  
Vol 264 (2) ◽  
pp. G213-G219 ◽  
Author(s):  
D. T. Valdez ◽  
A. Salapatek ◽  
G. Niznik ◽  
R. D. Linden ◽  
N. E. Diamant
Keyword(s):  
Electrical Stimulation ◽  
Stimulus Intensity ◽  
Magnetic Stimulation ◽  
Oropharyngeal Dysphagia ◽  
Sensory Stimulation ◽  
Upper Esophageal Sphincter ◽  
Twitch Contraction ◽  
Magnetic Stimulus ◽  
Esophageal Sphincter ◽  
Stimulation Of

This study in three dogs explores the effect of magnetically induced electrical stimulation of the brain to induce swallowing and produce contraction of the upper esophageal sphincter (UES). Single stimuli were delivered at intervals from 15 s to 3 min. Studies were performed with and without perfusion of fluid into the pharynx and upper esophagus. Results showed that magnetic stimulation produced a twitch contraction of the UES when stimulus intensity was above a threshold that varied between 14 and 20% of the stimulator output. Increasing stimulus intensity progressively increased twitch amplitude. Magnetic stimulation also induced swallowing, above a stimulus threshold similar to that for induction of the UES twitch contraction. Fluid perfusion augmented the ability of the magnetic stimulus to induce swallowing. We concluded that a magnetically induced single electrical stimulus of the cerebral cortex produces UES contraction and induces swallowing. The effect on swallowing is facilitated by sensory stimulation of the pharynx. This technique holds the potential for further study of 1) motor and sensory neural mechanisms involved in the control of swallowing and 2) the assessment and management of oropharyngeal dysphagia in humans.

A differential synaptic input to the motor nuclei of triceps surae from the caudal and lateral cutaneous sural nerves

1989 ◽  
Vol 61 (2) ◽  
pp. 291-301 ◽  
Author(s):  
L. A. LaBella ◽  
J. P. Kehler ◽  
D. A. McCrea
Keyword(s):  
Electrical Stimulation ◽  
Stimulus Intensity ◽  
Triceps Surae ◽  
Medial Gastrocnemius ◽  
Lateral Gastrocnemius ◽  
Motor Nuclei ◽  
Adult Cats ◽  
Predominant Effect ◽  
Sural Nerves ◽  
Stimulation Of

1. Postsynaptic potentials (PSPs) were recorded in 115 triceps surae motoneurons of 10 chloralose-anesthetized adult cats (spinal cord intact), upon electrical stimulation of the caudal and lateral cutaneous sural nerve branches (CCS and LCS, respectively). 2. With twice threshold (2T) stimulation of CCS, excitatory PSPs (EPSPs) were the predominant effect in 95% of all medial gastrocnemius (MG) motoneurons tested (min. central latency 1.5 ms; mean 2.4 ms). In only a few MG cells was the EPSP followed by an inhibitory postsynaptic potential (IPSP) and in only one cell was an IPSP the sole effect. Increasing the stimulus intensity to 5T tended to enhance both the later EPSP and IPSP components, with less change in the amplitude or latency of the earliest EPSPs. 3. In lateral gastrocnemius (LG) and soleus (SOL) motoneurons, 2T CCS stimulation led to either inhibition or no potential change in the majority of cells tested: EPSPs were the predominant effect in only 15 and 30% of LG and SOL cells, respectively (min. central latency 2.5 ms; mean 3.0 ms) and rarely occurred without subsequent inhibition. Again, increasing the stimulus intensity to 5T had more of an effect on later rather than earlier PSP components. 4. A predominance of depolarization in MG motoneurons but not in SOL motoneurons is in agreement with previous findings that CCS excitation is more powerful in "fast type" triceps surae motoneurons. However, the strong predominance of hyperpolarizing effects of CCS stimulation in the present LG population is evidence that such an organization does not transcend triceps surae motor nuclei as a whole. 5. Postsynaptic effects of LCS stimulation at 2T were frequently weak or absent but increasing the stimulus intensity to 5T produced predominant inhibition in 71% of all triceps surae motoneurons studied (n = 107). Of the few cells which did receive excitation from this nerve, most were MG, a few were SOL, and none were LG. These EPSPs occurred more frequently at 5T than at lower stimulation strengths. 6. The results indicate that excitation produced by electrical stimulation of the ipsilateral CCS nerve occurs preferentially in the MG portion of triceps surae and with the shortest central latencies. Effects of LCS stimulation are largely inhibitory throughout the motor nuclei comprising triceps surae but even here, the presence of excitation occurs more frequently in MG. A comparison of these results with those in other reports is discussed.

Neuromagnetic fields of the brain evoked by voluntary movement and electrical stimulation of the index finger

1995 ◽  
Vol 682 (1-2) ◽  
pp. 22-28 ◽  
Author(s):  
Rumyana Kristeva-Feige ◽  
Simone Rossi ◽  
Vittorio Pizzella ◽  
Franca Tecchio ◽  
Gian Luca Romani ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Voluntary Movement ◽  
Index Finger ◽  
The Brain ◽  
Stimulation Of

Synaptic potentials evoked by convergent somatosensory and corticocortical inputs in raccoon somatosensory cortex: substrates for plasticity

1991 ◽  
Vol 66 (3) ◽  
pp. 688-695 ◽  
Author(s):  
E. Smits ◽  
D. C. Gordon ◽  
S. Witte ◽  
D. D. Rasmusson ◽  
P. Zarzecki
Keyword(s):  
Electrical Stimulation ◽  
Somatosensory Cortex ◽  
Sole Source ◽  
Glabrous Skin ◽  
Synaptic Connections ◽  
Vibrotactile Stimulation ◽  
Single Digit ◽  
Natural Stimulation ◽  
Sensory Activity ◽  
Stimulation Of

1. "Unmasking" of weak synaptic connections has been suggested as a mechanism for the early changes in cortical topographic maps that follow alterations of sensory activity. For such a mechanism to operate, convergent sensory inputs must already exist in the normal cortex. 2. We tested for topographic and cross-modality convergence in primary somatosensory cortex of raccoon. The representation of glabrous skin of forepaw digits was chosen because, even though it is dominated by inputs from the glabrous skin of a single digit, it nevertheless comes to respond to stimulation of other digits when, e.g., a digit is removed. 3. Intracellular recordings were made from 109 neurons in the representation of glabrous skin of digit 4. Neurons were tested for somatosensory inputs with electrical and natural stimulation of digits. 4. Excitatory postsynaptic potentials (EPSPs) were evoked in 100% of the neurons (109/109) by electrical stimulation of glabrous skin of digit 4, and in 79% (31 of 39) by vibrotactile stimulation. 5. Glabrous skin of digit 4 was not the sole source of somatosensory inputs. A minority of neurons generated EPSPs after electrical stimulation of hairy skin of digit 4 (10 of 98 neurons, 10%). Electrical stimulation of digits 3 or 5 evoked EPSPs in 22 of 103 neurons (21%). Natural stimulation (vibrotactile or hair bending) was also effective in most of these latter cases (digit 3, 6/7; digit 5, 9/10). 6. Intracortical microstimulation of the "heterogeneous zone" was used to test for corticocortical connections to neurons in the glabrous zone.(ABSTRACT TRUNCATED AT 250 WORDS)

Responses of mitral/tufted cells to orthodromic and antidromic electrical stimulation in the olfactory bulb of the tiger salamander

1988 ◽  
Vol 59 (6) ◽  
pp. 1736-1755 ◽  
Author(s):  
K. A. Hamilton ◽  
J. S. Kauer
Keyword(s):  
Electrical Stimulation ◽  
Olfactory Bulb ◽  
Stimulus Intensity ◽  
Conditioning Stimulus ◽  
Excitatory Postsynaptic Potential ◽  
Paired Stimulus ◽  
Recording Electrode ◽  
Single Spike ◽  
Stimulation Of

1. Responses evoked by electrical stimulation of the olfactory nerve and olfactory tracts were analyzed in 46 output cells of the salamander olfactory bulb, in vivo. Labeling of several cells with horseradish peroxidase indicated that they were mitral and/or tufted neurons. The responses contained reproducible sequences of depolarizing and hyperpolarizing potentials, which changed with increases in stimulus intensity. 2. Stimulation of the nerve with intensities subthreshold for evoking spikes in the recorded cell resulted in a small depolarization followed by a period of hyperpolarization, during which spontaneous spikes were suppressed. With suprathreshold stimulus intensities, a single spike or often a burst of spikes was evoked, followed by a complex prolonged hyperpolarization. When full spikes were blocked by injecting hyperpolarizing current through the recording electrode, an excitatory postsynaptic potential (EPSP) with two major components and sometimes a fast prepotential were observed at the beginning of the response. Amplitudes of the EPSP and hyperpolarization increased with graded increases in stimulus intensity. In tests with paired stimulus volleys, spike generation was inhibited for at least 1 s and often for several seconds during the hyperpolarization. 3. Stimulation of the tracts with intensities subthreshold for evoking spikes in the recorded cell resulted in a complex prolonged hyperpolarization. With suprathreshold stimulus intensities, a single spike was evoked, followed by a similar period of hyperpolarization. When full spikes were blocked by injecting hyperpolarizing current through the recording electrode, a small antidromic spike, presumably generated in the axon or initial segment, was often observed. Amplitude of the hyperpolarization increased with graded increases in stimulus intensity. In tests with paired volleys, generation of a full antidromic spike was inhibited for a period that usually began 20-30 ms, following the spike evoked by the conditioning stimulus and lasted 100-500 ms. Full antidromic spikes were evoked prior to the period of inhibition and small antidromic spikes were evoked during the period. 4. The mean latencies of single evoked spikes or the first spikes of bursts decreased from 22 to 17 ms with increases in the intensity of nerve stimulation and from 7 to 6 ms with increases in the intensity of tract stimulation. Only decreases in orthodromic latency were significant at P less than or equal to 0.05, as determined by one-sided t tests between the means of responses subdivided according to response pattern and relative stimulus intensity.(ABSTRACT TRUNCATED AT 400 WORDS)

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