An Attempt to Demonstrate Contralateral Masking in Pressure Adaptation

1972 ◽  
Vol 35 (3) ◽  
pp. 856-858 ◽  
Author(s):  
Stanley Finger ◽  
Harvey S. Levin
Keyword(s):  
Test Stimulus ◽  
Somatosensory System ◽  
Adaptation Time ◽  
Contralateral Stimulation ◽  
Pressure Adaptation ◽  
Masking Stimulus ◽  
Contralateral Masking ◽  
Stimulation Of

Adaptation to punctate pressure Stimulation of the ring finget (test stimulus) was studied under conditions of more intense contralateral stimulation of homologous or non-homologous loci (masking stimuli). Contrary to expectation, the temporally contiguous masking stimulus did not affect adaptation time to the test stimulus. This finding was discussed in terms of other tactile masking studies and electrophysiological investigations of the somatosensory system.

scholarly journals Different Patterns of Attention Modulation in Early N140 and Late P300 sERPs Following Ipsilateral vs. Contralateral Stimulation at the Fingers and Cheeks

2021 ◽  
Vol 15 ◽  
Author(s):  
Laura Lindenbaum ◽  
Sebastian Zehe ◽  
Jan Anlauff ◽  
Thomas Hermann ◽  
Johanna Maria Kissler
Keyword(s):  
Body Part ◽  
Oddball Paradigm ◽  
Body Parts ◽  
Somatosensory Processing ◽  
Hemispheric Processing ◽  
Contralateral Stimulation ◽  
Early Processing ◽  
Similarities And Differences ◽  
Ipsilateral Stimulation ◽  
Stimulation Of

Intra-hemispheric interference has been often observed when body parts with neighboring representations within the same hemisphere are stimulated. However, patterns of interference in early and late somatosensory processing stages due to the stimulation of different body parts have not been explored. Here, we explore functional similarities and differences between attention modulation of the somatosensory N140 and P300 elicited at the fingers vs. cheeks. In an active oddball paradigm, 22 participants received vibrotactile intensity deviant stimulation either ipsilateral (within-hemisphere) or contralateral (between-hemisphere) at the fingers or cheeks. The ipsilateral deviant always covered a larger area of skin than the contralateral deviant. Overall, both N140 and P300 amplitudes were higher following stimulation at the cheek and N140 topographies differed between fingers and cheek stimulation. For the N140, results showed higher deviant ERP amplitudes following contralateral than ipsilateral stimulation, regardless of the stimulated body part. N140 peak latency differed between stimulated body parts with shorter latencies for the stimulation at the fingers. Regarding P300 amplitudes, contralateral deviant stimulation at the fingers replicated the N140 pattern, showing higher responses and shorter latencies than ipsilateral stimulation at the fingers. For the stimulation at the cheeks, ipsilateral deviants elicited higher P300 amplitudes and longer latencies than contralateral ones. These findings indicate that at the fingers ipsilateral deviant stimulation leads to intra-hemispheric interference, with significantly smaller ERP amplitudes than in contralateral stimulation, both at early and late processing stages. By contrast, at the cheeks, intra-hemispheric interference is selective for early processing stages. Therefore, the mechanisms of intra-hemispheric processing differ from inter-hemispheric ones and the pattern of intra-hemispheric interference in early and late processing stages is body-part specific.

Acute resetting of baroreceptor reflex in rabbits: a central component

1986 ◽  
Vol 250 (5) ◽  
pp. H866-H870 ◽  
Author(s):  
D. L. Kunze
Keyword(s):  
Arterial Pressure ◽  
Test Stimulus ◽  
Nerve Stimulation ◽  
Sympathetic Activity ◽  
Constant Stimulus ◽  
Baroreceptor Reflex ◽  
Pressure Response ◽  
Stimulus Period ◽  
Aortic Nerve ◽  
Stimulation Of

Electrical stimulation of the aortic nerve of the anesthetized rabbit was used to determine whether there is a central nervous system component to acute resetting of the baroreceptor reflex. After stimulation of the aortic nerve for 5 min at 10 Hz, a ramp test stimulus to the nerve produced a reflex arterial pressure response that was attenuated as compared with that produced by the same ramp prior to the five-min stimulation period. Renal sympathetic nerve activity was recorded simultaneously to determine whether a reduction in the magnitude of the reflex inhibition of sympathetic activity produced by the depressor nerve stimulation could account for the attenuated arterial pressure response. Renal activity during the test ramp was reduced to the same value both before and after the constant stimulus period and thus did not correlate with the attenuated pressure response. There was, however, prolonged inhibition of tonic sympathetic activity after the 5-min stimulus period such that during the test stimulus there was less sympathetic activity to inhibit. The results were similar when sympathetic activity was recorded from branches of the sciatic nerve and from thoracic postganglionic nerves. In these nerves the period of prolonged inhibition after aortic nerve stimulation was up to 5 min. The attenuated pressure response to baroreceptor nerve stimulation after a constant stimulus appears to reflect the reduced change in sympathetic activity rather than the value to which the sympathetic activity falls.

Functional specialization of central projections from identified primary afferent fibers

1988 ◽  
Vol 60 (5) ◽  
pp. 1597-1614 ◽  
Author(s):  
H. R. Koerber ◽  
L. M. Mendell
Keyword(s):  
Test Stimulus ◽  
Conditioning Stimulus ◽  
Hair Follicles ◽  
Single Fiber ◽  
High Frequency Stimulation ◽  
High Threshold ◽  
Primary Afferent ◽  
Afferent Fibers ◽  
Primary Afferent Fibers ◽  
Stimulation Of

1. Somata of primary afferent fibers were impaled in the L7 or S1 dorsal root ganglion in cats anesthetized with alpha-chloralose. Individual cells (n = 182) were characterized according to receptive field (RF) and by the peripheral mechanoreceptor they innervated. They were then stimulated intracellularly while recording the evoked cord dorsum potentials (CDPs) simultaneously at four sites. CDPs were recorded in response to single fiber stimulation while varying both the frequency and the numbers of action potentials (APs) evoked per trial. Stimulus parameters included: 1) single APs evoked at both high (18 Hz) and low (0.67 Hz) frequencies, 2) pairs of APs (50-ms ISI) delivered at 0.67 Hz, and 3) trains of four APs (20-ms ISI) also delivered at 0.67 Hz. The properties of the CDPs and their relationship to receptor type innervated by the fiber were determined. 2. CDPs evoked by 18-Hz stimulation consisted of an axon fiber spike followed at a short latency [600 +/- 9.9 (SEM) microseconds] by the onset of a monophasic negative wave. A-beta-afferent fibers innervating slowly adapting type 1 and 2 receptors (SA1 and SA2) evoked the largest amplitude CDPs followed by field and hair follicle afferents while A-delta-fibers rarely produced measurable CDPs at this frequency of stimulation. 3. The magnitude of the CDP varied at the four recording sites with clear evidence in individual experiments that the projections of individual fibers are somatotopically organized. 4. CDPs evoked by 0.67-Hz stimulation had the same onset latency but were larger in amplitude and had longer time-to-peak and durations than those elicited by high frequency stimulation. Under these conditions A-beta-fibers innervating hair follicles produced the largest CDPs followed by field receptors and SA1s and SA2s. A-beta- and A-delta-fibers innervating high threshold mechanoreceptors (HTMRs) and A-delta-fibers innervating down hair follicles (D-hairs) produced CDPs of amplitude and duration similar to those evoked by slower A-beta-fibers. 5. The response to a test stimulus delivered 50 ms after a conditioning stimulus to the same single fiber was always depressed in the case of A-beta-fibers supplying rapidly adapting receptors. The conditioning stimulus exerted relatively little effect on the response to the test stimulus for A-beta- fibers innervating slowly adapting receptors. The test response to stimulation of A-beta- and A-delta- fibers innervating HTMRs was consistently facilitated while stimulation of A-delta- D-hairs evoked either marked facilitation or slight depression.(ABSTRACT TRUNCATED AT 400 WORDS)

Opponent Hues in Visual Masking

1978 ◽  
Vol 46 (3) ◽  
pp. 979-983
Author(s):  
Michael Gamble
Keyword(s):  
Test Stimulus ◽  
Color Vision ◽  
Visual Masking ◽  
Masking Effect ◽  
Subjective Confidence ◽  
Temporal And Spatial ◽  
Masking Stimulus ◽  
Temporal Interactions ◽  
Temporal Sequences ◽  
Forward Sequence

Temporal interactions among opponent and non-opponent hues were investigated in a visual masking paradigm in which both backward and forward temporal sequences were employed. Subjective confidence ratings rather than identification thresholds alone served as response indicators for masking sequences. Results indicate that in the backward sequence (test stimulus followed by masking stimulus) a greater masking effect occurred when the stimuli were of non-opponent hue pairs (red-yellow, red-blue, green-yellow, green-blue) than when compared with opponent hue pairs (red-green, yellow-blue). For the forward sequence (test stimulus preceded by masking stimulus) the masking effect was reduced when compared with the backward sequence. These findings appear to reflect the presumed temporal and spatial antagonistic qualities of opponent hue processes as postulated in the Hering model of color vision.

Effects of Locus Ceruleus and Olfactory Bulb Stimulation on Rat Olfactory Tubercle Neuron Activity

1988 ◽  
Vol 98 (2) ◽  
pp. 116-120 ◽  
Author(s):  
Akira Inokuchi ◽  
Thomas V. Boran ◽  
Charles P. Kimmelman ◽  
James B. Snow
Keyword(s):  
Olfactory Bulb ◽  
Evoked Potential ◽  
Locus Ceruleus ◽  
Neuron Activity ◽  
Noradrenergic System ◽  
Olfactory Tubercle ◽  
Contralateral Stimulation ◽  
Ipsilateral Stimulation ◽  
Stimulation Of

The effects of electrical stimulation of the olfactory bulb and the locus ceruleus on olfactory tubercle neurons were examined in rat models. Ipsilateral stimulation of the olfactory bulb produced excitation in 31% of olfactory tubercle neurons tested and inhibition in 17%. Twenty-two percent of the olfactory tubercle neurons were excited, whereas 9% were inhibited by ipsilateral stimulation of the locus ceruleus. Contralateral stimulation of the locus ceruleus produced similar responses in the same neuron entities. A negative-positive evoked potential was recorded in the olfactory tubercle after ipsilateral and contralateral stimulation of the locus ceruleus. Thirty-three percent of the olfactory tubercle neurons that responded orthodromically or antidromically to stimulation of the olfactory bulb were excited by ipsilateral stimulation of the locus ceruleus. In contrast, only 10% responded with excitation to ipsilateral stimulation of the locus ceruleus among the olfactory tubercle neurons that were unresponsive to stimulation of the olfactory bulb. These findings suggest that olfactory tubercle neurons that receive input from or sending output to the olfactory bulb are influenced by the noradrenergic system of the locus ceruleus. A possible role of the olfactory tubercle in olfactory transduction will also be discussed.

Visual and Multimodal Interneurones in the Ventral Nerve Cord of the Cockroach, Periplaneta Americana

1973 ◽  
Vol 59 (3) ◽  
pp. 675-696
Author(s):  
R. J. COOTER
Keyword(s):  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Tactile Stimulation ◽  
Periplaneta Americana ◽  
Compound Eye ◽  
Visual Stimulation ◽  
Contralateral Stimulation ◽  
Thoracic Nerve ◽  
General Properties ◽  
Stimulation Of

1. Visual and multimodal units were recorded from the thoracic nerve cord of the cockroach, Periplaneta americana, using glass microelectrodes. 2. Compound-eye units could be classified as ON-, OFF- or ON-OFF-units according to their response to visual stimulation. Some were multimodal, firing to both visual and tactile stimulation of the antennae. 3. Although some units were found to be either fired by ipsilateral or by contralateral stimulation only, others were fired by both types of stimulation, often in different ways. 4. Ocellar units were invariably OFF-units, mainly phasic, but one type showed tonic dark-firing in addition to the phasic OFF-burst. 5. The general properties of cockroach visual units are discussed and compared with those reported by other workers for different insects.

Visual Masking with Presentations in Same and opposite Visual Fields: Evidence for Contralateral Masking

1982 ◽  
Vol 55 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Dennis P. Saccuzzo ◽  
Brad E. Michael ◽  
Robert Rowe
Keyword(s):  
Visual Field ◽  
Target Stimulus ◽  
Visual Masking ◽  
Visual Fields ◽  
Right Visual Field ◽  
Future Research ◽  
Backward Masking ◽  
Masking Stimulus ◽  
The Right ◽  
Contralateral Masking

Three experiments were conducted in a preliminary attempt to study the effects of presentations of an informational target stimulus to the right or left visual fields when the target was either preceded or followed by a non-informational masking stimulus and when the mask was presented to the same or opposite visual field of the target. Results indicated that masking was more effective in the same than in the opposite visual field but that masking of the opposite visual field was feasible for both forward and backward masking. Laterality effects were also found for forward and backward masking, with a modest advantage of the right visual field (left hemisphere) in both cases. Limitations of the data and directions for future research were discussed.

Central Response to Infra-Red Stimulation of the Pit Receptors in a Crotaline Snake, Trimeresurus Flavoviridis

1973 ◽  
Vol 58 (1) ◽  
pp. 59-76 ◽  
Author(s):  
RICHARD C. GORIS ◽  
SHIN-ICHI TERASHIMA
Keyword(s):  
Action Potentials ◽  
Firing Frequency ◽  
Single Units ◽  
Stimulus Movement ◽  
Firing Patterns ◽  
Contralateral Stimulation ◽  
Trimeresurus Flavoviridis ◽  
Infra Red ◽  
Central Response ◽  
Stimulation Of

1. Both action potentials and evoked potentials were recorded from the tectum opticum of a crotaline snake, Trimeresurus flavoviridis, in response to infra-red stimulation of the facial pit organs. Action potentials from single units were recorded throughout the tectum. 2. Most units responded to contralateral stimulation, while some responded to both ipsi- and contralateral stimulation. 3. Firing patterns were tonic, phasic, or phasic-tonic, depending on the position of the stimulus and the type of unit being recorded. 4. Sensitivity to stimulus movement was observed. 5. All potentials differed from peripheral potentials in firing patterns. 6. Firing frequency was directly proportional to stimulus intensity. 7. Measurements were made of the vertical and horizontal response fields of single units. 8. Background discharge was noted in all units and its nature discussed. 9. The integrative function of the tectum in regard to infra-red perception was also discussed, as well as the possibility of stereoscopic perception.

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