scholarly journals The third-stimulus temporal discrimination threshold: focusing on the temporal processing of sensory input within primary somatosensory cortex

2017 ◽  
Vol 118 (4) ◽  
pp. 2311-2317 ◽  
Author(s):  
Giorgio Leodori ◽  
Alessandra Formica ◽  
Xiaoying Zhu ◽  
Antonella Conte ◽  
Daniele Belvisi ◽  
...  
Keyword(s):  
Temporal Discrimination ◽  
Sensory Information ◽  
Discrimination Threshold ◽  
New Method ◽  
Time Interval ◽  
The Third ◽  
Tactile Stimuli ◽  
Temporal Encoding ◽  
Perception Process ◽  
Theta Burst

The somatosensory temporal discrimination threshold (STDT) has been used in recent years to investigate time processing of sensory information, but little is known about the physiological correlates of somatosensory temporal discrimination. The objective of this study was to investigate whether the time interval required to discriminate between two stimuli varies according to the number of stimuli in the task. We used the third-stimulus temporal discrimination threshold (ThirdDT), defined as the shortest time interval at which an individual distinguishes a third stimulus following a pair of stimuli delivered at the STDT. The STDT and ThirdDT were assessed in 31 healthy subjects. In a subgroup of 10 subjects, we evaluated the effects of the stimuli intensity on the ThirdDT. In a subgroup of 16 subjects, we evaluated the effects of S1 continuous theta-burst stimulation (S1-cTBS) on the STDT and ThirdDT. Results show that ThirdDT is shorter than STDT. We found a positive correlation between STDT and ThirdDT values. As long as the stimulus intensity was within the perceivable and painless range, it did not affect ThirdDT values. S1-cTBS significantly affected both STDT and ThirdDT, although the latter was affected to a greater extent and for a longer period of time. We conclude that the interval needed to discriminate between time-separated tactile stimuli is related to the number of stimuli used in the task. STDT and ThirdDT are encoded in S1, probably by a shared tactile temporal encoding mechanism whose performance rapidly changes during the perception process. ThirdDT is a new method to measure somatosensory temporal discrimination. NEW & NOTEWORTHY To investigate whether the time interval required to discriminate between stimuli varies according to changes in the stimulation pattern, we used the third-stimulus temporal discrimination threshold (ThirdDT). We found that the somatosensory temporal discrimination acuity varies according to the number of stimuli in the task. The ThirdDT is a new method to measure somatosensory temporal discrimination and a possible index of inhibitory activity at the S1 level.

scholarly journals Hearing Shapes Our Perception of Time: Temporal Discrimination of Tactile Stimuli in Deaf People

2012 ◽  
Vol 24 (2) ◽  
pp. 276-286 ◽  
Author(s):  
Nadia Bolognini ◽  
Carlo Cecchetto ◽  
Carlo Geraci ◽  
Angelo Maravita ◽  
Alvaro Pascual-Leone ◽  
...  
Keyword(s):  
Temporal Processing ◽  
Temporal Discrimination ◽  
Sensory Information ◽  
Association Cortex ◽  
Cortical Level ◽  
Tactile Stimuli ◽  
Sensory Modalities ◽  
Neural Substrate ◽  
Perception Of Time ◽  
Auditory Association Cortex

Confronted with the loss of one type of sensory input, we compensate using information conveyed by other senses. However, losing one type of sensory information at specific developmental times may lead to deficits across all sensory modalities. We addressed the effect of auditory deprivation on the development of tactile abilities, taking into account changes occurring at the behavioral and cortical level. Congenitally deaf and hearing individuals performed two tactile tasks, the first requiring the discrimination of the temporal duration of touches and the second requiring the discrimination of their spatial length. Compared with hearing individuals, deaf individuals were impaired only in tactile temporal processing. To explore the neural substrate of this difference, we ran a TMS experiment. In deaf individuals, the auditory association cortex was involved in temporal and spatial tactile processing, with the same chronometry as the primary somatosensory cortex. In hearing participants, the involvement of auditory association cortex occurred at a later stage and selectively for temporal discrimination. The different chronometry in the recruitment of the auditory cortex in deaf individuals correlated with the tactile temporal impairment. Thus, early hearing experience seems to be crucial to develop an efficient temporal processing across modalities, suggesting that plasticity does not necessarily result in behavioral compensation.

scholarly journals Tectono-Sedimentary Evolution of the Cenozoic Basins in the Eastern External Betic Zone (SE Spain)

Geosciences ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 394
Author(s):  
Manuel Martín-Martín ◽  
Francesco Guerrera ◽  
Mario Tramontana
Keyword(s):  
Strike Slip ◽  
Alluvial Fan ◽  
Tectonic Activity ◽  
Time Interval ◽  
Se Spain ◽  
The Third ◽  
Sedimentary Evolution ◽  
Marine Sedimentation ◽  
Geodynamic Processes ◽  
Early Paleocene

Four main unconformities (1–4) were recognized in the sedimentary record of the Cenozoic basins of the eastern External Betic Zone (SE, Spain). They are located at different stratigraphic levels, as follows: (1) Cretaceous-Paleogene boundary, even if this unconformity was also recorded at the early Paleocene (Murcia sector) and early Eocene (Alicante sector), (2) Eocene-Oligocene boundary, quite synchronous, in the whole considered area, (3) early Burdigalian, quite synchronous (recognized in the Murcia sector) and (4) Middle Tortonian (recognized in Murcia and Alicante sectors). These unconformities correspond to stratigraphic gaps of different temporal extensions and with different controls (tectonic or eustatic), which allowed recognizing minor sedimentary cycles in the Paleocene–Miocene time span. The Cenozoic marine sedimentation started over the oldest unconformity (i.e., the principal one), above the Mesozoic marine deposits. Paleocene-Eocene sedimentation shows numerous tectofacies (such as: turbidites, slumps, olistostromes, mega-olistostromes and pillow-beds) interpreted as related to an early, blind and deep-seated tectonic activity, acting in the more internal subdomains of the External Betic Zone as a result of the geodynamic processes related to the evolution of the westernmost branch of the Tethys. The second unconformity resulted from an Oligocene to Aquitanian sedimentary evolution in the Murcia Sector from marine realms to continental environments. This last time interval is characterized as the previous one by a gentle tectonic activity. On the other hand, the Miocene sedimentation was totally controlled by the development of superficial thrusts and/or strike-slip faults zones, both related to the regional geodynamic evolutionary framework linked to the Mediterranean opening. These strike-slip faults zones created subsidence areas (pull-apart basin-type) and affected the sedimentation lying above the third unconformity. By contrast, the subsidence areas were bounded by structural highs affected by thrusts and folds. After the third unconformity, the Burdigalian-Serravallian sedimentation occurred mainly in shallow- to deep-water marine environments (Tap Fm). During the Late Miocene, after the fourth unconformity, the activation of the strike-slip faults zones caused a shallow marine environment sedimentation in the Murcia sector and a continental (lacustrine and fluvial) deposition in the Alicante sector represented the latter, resulting in alluvial fan deposits. Furthermore, the location of these fans changed over time according to the activation of faults responsible for the tectonic rising of Triassic salt deposits, which fed the fan themselves.

Timing, Storage, and Comparison of Stimulus Duration Engage Discrete Anatomical Components of a Perceptual Timing Network

2008 ◽  
Vol 20 (12) ◽  
pp. 2185-2197 ◽  
Author(s):  
Jennifer T. Coull ◽  
Bruno Nazarian ◽  
Franck Vidal
Keyword(s):  
Stimulus Duration ◽  
Brain Activity ◽  
Temporal Discrimination ◽  
Superior Temporal Gyrus ◽  
Motor Preparation ◽  
Long Term Memory ◽  
Temporal Encoding ◽  
Perceptual Timing ◽  
The Right

The temporal discrimination paradigm requires subjects to compare the duration of a probe stimulus to that of a sample previously stored in working or long-term memory, thus providing an index of timing that is independent of a motor response. However, the estimation process itself comprises several component cognitive processes, including timing, storage, retrieval, and comparison of durations. Previous imaging studies have attempted to disentangle these components by simply measuring brain activity during early versus late scanning epochs. We aim to improve the temporal resolution and precision of this approach by using rapid event-related functional magnetic resonance imaging to time-lock the hemodynamic response to presentation of the sample and probe stimuli themselves. Compared to a control (color-estimation) task, which was matched in terms of difficulty, sustained attention, and motor preparation requirements, we found selective activation of the left putamen for the storage (“encoding”) of stimulus duration into working memory (WM). Moreover, increased putamen activity was linked to enhanced timing performance, suggesting that the level of putamen activity may modulate the depth of temporal encoding. Retrieval and comparison of stimulus duration in WM selectively activated the right superior temporal gyrus. Finally, the supplementary motor area was equally active during both sample and probe stages of the task, suggesting a fundamental role in timing the duration of a stimulus that is currently unfolding in time.

scholarly journals Measurement & Analysis of the Temporal Discrimination Threshold Applied to Cervical Dystonia

10.3791/56310 ◽  
2018 ◽  
Author(s):  
Rebecca B Beck ◽  
Eavan M McGovern ◽  
John S Butler ◽  
Dorina Birsanu ◽  
Brendan Quinlivan ◽  
...  
Keyword(s):  
Cervical Dystonia ◽  
Temporal Discrimination ◽  
Discrimination Threshold

Sensory Activation and Receptive Field Organization of the Lateral Giant Escape Neurons in Crayfish

2010 ◽  
Vol 104 (2) ◽  
pp. 675-684 ◽  
Author(s):  
Yen-Chyi Liu ◽  
Jens Herberholz
Keyword(s):  
Action Potential ◽  
Procambarus Clarkii ◽  
Receptive Fields ◽  
Sensory Information ◽  
Tactile Stimuli ◽  
Field Organization ◽  
Tail Flip ◽  
Receptive Field Organization ◽  
Sensory Activation ◽  
Stimulation Of

Crayfish ( Procambarus clarkii ) have bilateral pairs of giant interneurons that control rapid escape movements in response to predatory threats. The medial giant neurons (MGs) can be made to fire an action potential by visual or tactile stimuli directed to the front of the animal and this leads to an escape tail-flip that thrusts the animal directly backward. The lateral giant neurons (LGs) can be made to fire an action potential by strong tactile stimuli directed to the rear of the animal, and this produces flexions of the abdomen that propel the crayfish upward and forward. These observations have led to the notion that the receptive fields of the giant neurons are locally restricted and do not overlap with each other. Using extra- and intracellular electrophysiology in whole animal preparations of juvenile crayfish, we found that the receptive fields of the LGs are far more extensive than previously assumed. The LGs receive excitatory inputs from descending interneurons originating in the brain; these interneurons can be activated by stimulation of the antenna II nerve or the protocerebral tract. In our experiments, descending inputs alone could not cause action potentials in the LGs, but when paired with excitatory postsynaptic potentials elicited by stimulation of tail afferents, the inputs summed to yield firing. Thus the LG escape neurons integrate sensory information received through both rostral and caudal receptive fields, and excitatory inputs that are activated rostrally can bring the LGs' membrane potential closer to threshold. This enhances the animal's sensitivity to an approaching predator, a finding that may generalize to other species with similarly organized escape systems.

scholarly journals Botulinum Toxin Effects on Sensorimotor Integration in Focal Dystonias

Toxins ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 277
Author(s):  
Maria Ilenia De Bartolo ◽  
Nicoletta Manzo ◽  
Gina Ferrazzano ◽  
Viola Baione ◽  
Daniele Belvisi ◽  
...  
Keyword(s):  
Botulinum Toxin ◽  
Sensorimotor Integration ◽  
Index Finger ◽  
Botulinum Toxin A ◽  
Temporal Discrimination ◽  
Discrimination Threshold ◽  
Focal Dystonia ◽  
Movement Execution ◽  
Proprioceptive Input ◽  
Hand Dystonia

(1) Background: In dystonia, the somatosensory temporal discrimination threshold (STDT) is abnormally increased at rest and higher and longer-lasting during movement execution in comparison with healthy subjects (HS), suggesting an abnormal sensorimotor integration. These abnormalities are thought to depend on abnormal proprioceptive input coming from dystonic muscles. Since Botulinum toxin-A (BT-A) reduces proprioceptive input in the injected muscles, our study investigated the effects of BT-A on STDT tested at rest and during voluntary movement execution in patients with focal dystonia. (2) Methods: We enrolled 35 patients with focal dystonia: 14 patients with cervical dystonia (CD), 11 patients with blepharospasm (BSP), and 10 patients with focal hand dystonia (FHD); and 12 age-matched HS. STDT tested by delivering paired stimuli was measured in all subjects at rest and during index finger abductions. (3) Results: Patients with dystonia had higher STDT values at rest and during movement execution than HS. While BT-A did not modify STDT at rest, it reduced the abnormal values of STDT during movement in CD and FHD patients, but not in BSP patients. (4) Conclusions: BT-A improved abnormal sensorimotor integration in CD and FHD, most likely by decreasing the overflow of proprioceptive signaling from muscle dystonic activity to the thalamus.

scholarly journals Temporal discrimination threshold and blink reflex recovery cycle in cervical dystonia – two sides of the same coin?

2019 ◽  
Vol 68 ◽  
pp. 4-7 ◽  
Author(s):  
Johanna Junker ◽  
Theresa Paulus ◽  
Valerie Brandt ◽  
Anne Weissbach ◽  
Sinem Tunc ◽  
...  
Keyword(s):  
Cervical Dystonia ◽  
Temporal Discrimination ◽  
Blink Reflex ◽  
Discrimination Threshold ◽  
Recovery Cycle ◽  
Two Sides

Modifications of Locomotor Pattern Underlying Escape Behavior in the Lamprey

2008 ◽  
Vol 99 (1) ◽  
pp. 297-307 ◽  
Author(s):  
Salma S. Islam ◽  
Pavel V. Zelenin
Keyword(s):  
Spinal Cord ◽  
Escape Behavior ◽  
Sensory Information ◽  
The Body ◽  
Descending Pathways ◽  
Long Distance ◽  
Lower Vertebrate ◽  
Dorsal Roots ◽  
Tactile Stimuli ◽  
Undulatory Locomotion

Two forms of undulatory locomotion in the lamprey (a lower vertebrate) have been described earlier: fast forward swimming (FFS) used for long distance migrations and slow backward swimming (SBS) used for escape from adverse tactile stimuli. In the present study, we describe another form of escape behavior: slow forward swimming (SFS). We characterize the kinematic and electromyographic patterns of SFS and compare them with SBS and FFS. The most striking feature of SFS is nonuniformity of shape and speed of the locomotor waves propagating along the body: close to the site of stimulation, the waves slow down and the body curvature increases several-fold due to enhanced muscle activity. Lesions of afferents showed that sensory information critical for elicitation of SFS is transmitted through the dorsal roots. In contrast, sensory signals that induce SBS are transmitted through the dorsal roots, lateral line nerves, and trigeminal nerves. Persistence of SFS and SBS after different lesions of the spinal cord suggests that the ascending and descending pathways, necessary for induction of SBS and SFS, are dispersed over the cross section of the spinal cord. As shown previously, during FFS (but not SBS) the lamprey maintains the dorsal-side-up body orientation due to vestibular postural reflexes. In this study we have found that the orientation control is absent during SFS. The role of the spinal cord and the brain stem in generation of different forms of undulatory locomotion is discussed.

Pharmacokinetics of ethanol and its metabolite, acetaldehyde, and fetolethality in the third-trimester pregnant guinea pig for oral administration of acute, multiple-dose ethanol

1986 ◽  
Vol 64 (8) ◽  
pp. 1060-1067 ◽  
Author(s):  
David W. Clarke ◽  
Nancy A. E. Steenaart ◽  
Christopher J. Slack ◽  
James F. Brien
Keyword(s):  
Guinea Pig ◽  
Amniotic Fluid ◽  
Ethanol Concentration ◽  
Fetal Brain ◽  
Maternal Blood ◽  
Time Interval ◽  
Gas Liquid Chromatography ◽  
Fetal Blood ◽  
Third Trimester ◽  
The Third

The pharmacokinetics of ethanol and its metabolite, acetaldehyde, were determined in the third-trimester pregnant guinea pig (56–59 days gestation) for oral intubation of four doses of 1 g ethanol/kg maternal body weight, administered at 1-h intervals. Animals (n = 4–7) were sacrificed at each of selected times during the 26-h study. Ethanol and acetaldehyde concentrations were determined by headspace gas-liquid chromatography. The maternal and fetal blood ethanol concentration–time curves were virtually superimposable, which indicated unimpeded bidirectional placental transfer of ethanol in the matemal–fetal unit. The blood and brain ethanol concentrations were similar in each of the maternal and fetal compartments during the study, which indicated rapid equilibrium distribution of ethanol. There was accumulation of ethanol in the amniotic fluid resulting in higher ethanol concentration compared with maternal and fetal blood during the elimination phase, which indicated that the amniotic fluid may serve as a reservoir for ethanol in utero. Acetaldehyde was measurable in all the biological fluids and tissues at concentrations that were at least 1000-fold less than the respective ethanol concentrations and were variable. There was ethanol-induced fetolethality that was delayed and variable among animals, and was 55% at 23 h. At this time interval, the ethanol concentrations in maternal blood and brain, fetal brain, and amniotic fluid were 35- to 53-fold greater and the acetaldehyde concentrations in maternal blood and fetal brain were four- to five-fold higher in the animals with dead fetuses compared with the guinea pigs with live litters. These data indicated that decreased ethanol elimination from the maternal–fetal unit was related temporally to the fetolethality.

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