Tag Archives: NeuroPhysiology

thermal taster

Do you know what your thermal taster status is?

Thermal taster status (TTS) is a phenomenon in which thermal stimulation of specific areas of the tongue, causes a sensation of a distinct taste in the absence of a gustatory stimulus. Reports vary on what percentage of the general population is a thermal taster, occurrence of thermal tasters in research cohorts of between 20% and 50% has been reported.

thermal taster

Not all Thermal Tasters taste alike

Even within the group of thermal tasters, there are subgroups. These groups differ from one another in responsiveness to thermal stimuli in different areas of the tongue and the phantom taste that each type of stimulation arouses. Green and George report that “thermal sweetness” is a common taste occurring in half the thermal tasters in response to warming after the tongue was cooled, while Skinner et al. reported 25% of tasters tasting “bitter” while another 25% tasting “sour” in cooling trials.

How to assess Thermal Taste

In general, TTS is assessed by applying a thermode with a warming and a cooling stimulus, as each temperature change direction and specific temperatures elicits a different taste sensation in thermal tasters. Thermal taste is classically tested on the tip of the tongue, and some studies report findings from areas lateral of the tip or the back of the tongue. Several studies on thermal tasters have used Medoc’s Pathway 16*16 mm thermode or the Intra-oral thermode. An example of a testing protocol for TTS could be found in Eldeghaidy et al.’s study in which both warming trials and cooling trials were applied. A warming trial would start at 35°C, cooled down to 15°C and go up to 40°C, and held there for 10 sec., with a ramp of 1 °C/sec.

Tongue taste innervation

In Thermal tasters, the anterior part of the tongue, innervated by the chorda tympani nerve, shows a typical reaction to heating and to cooling, while the posterior part of the tongue, innervated by the glossopharyngeal nerve, reacts less typically, Cruz and Green found[7]. Thermal taster status, along with another measure, 6-npropylthiouracil (PROP) taster status, form the taste phenotype.

Do fungiform papillae matter?

A hypothesis existed that the fungiform papillae of the tongue would be responsible for thermal taste because of their high density at the tip of the tongue, and their dual role: as they contain both taste buds and mechanoreceptors that are innervated by gustatory and trigeminal nerve fibers. Eldeghaidy et al. found that TTS did not seem to be correlated to fungiform papillae density in contrast to PROP taster status, and thus must have a different mechanism. The taste phenotype as a whole, and the thermal taster status specifically, increasingly allure both neurology researchers and the food and beverage industry alike. Temperature may be actively integrated as a contributor in the totality of the gustatory experience when new taste product are planned to be released to market.



Medoc Thermodes

Fit to a T(hermode)

Medoc Thermodes

We are often asked by our customers: “what thermode should I use?” Our answer is usually: “it depends”.

This is one of the most common questions we are asked when a customer approaches us, intending to buy a thermal quantitative sensory testing (QST) device.

The thermode is the probe that is attached to the participants’ skin, that on command of the computer program changes its temperature to hot or cold.

There are several types of thermodes; which one fits you best, depends mostly on your intended use.

Let’s start with the basics:

Comparing and contrasting

The classic thermode size is the 30mm by 30mm contact surface thermode, or for short: the 30*30. This thermode size has been around for decades and has therefor gathered quite the following.

Most of the normative data that has been gathered with Medoc devices around the world, and specifically by the German Research Network on Neuropathic Pain, the DFNS, has been gathered with this 30*30 thermode[1],[2],[3]. If you intend to compare your QST results to normative values that have been collected from healthy participants, you may want to consider using the 30*30.

Another quite common thermode size is the 16*16. This thermode has been in use with researchers and clinicians who wish to stimulate smaller areas, like the face[4] or the tongue[5], or perform QST on children[6].

Need for speed

One of the most asked-about thermodes is the CHEPS thermode. This thermode is special, because its technology allows working at very high speeds, for both heat and cold stimulation.

These high speeds are especially important for researchers who want to use a fast thermal stimulation in order to record Contact Heat Evoked Potentials (CHEPs)[7],[8],[9] or Cold Evoked Potentials (CEPs)[10]. Others may be interested in an application called: phasic heat temporal summation, in which very fast noxious heat pulses are applied in order to test for the wind-up phenomenon[11],[12].

Visualizing pain

The above thermode types (30*30, 16*16, CHEPS) are also available in fMRI versions. fMRI thermodes are different from normal thermodes for having additional 10 meters cable length, allowing the device to be placed outside the magnetic chamber and only the thermode to pass through the waveguide, reducing noise artifacts and insuring safety. These thermodes have undergone thorough testing and validation in different MRI environments.

Thermal stimulation is used in many trials that examined psychology (including reward processing, mindfulness, and more)[13],[14] and pain neurophysiology[15],[16].

Not your run of the mill thermode..

Then there are the specialized thermodes. Some quantitative sensory testing has been conducted on the most uncommon places in the body, to elucidate specific issues.

Intra-oral testing is conducted with a small diameter Intraoral thermode for varying purposes like; tooth sensitivity[17],[18], pain disorders involving the mouth or the face[19]and thermal taster status.

Medoc’s Intravaginal thermode, formerly known as the Genito-sensory-analyzer (GSA) is utilized in studies which seek to assess somatosensory function and pain of the genital area in women[20],[21],[22] and men[23].


References: [1]Hafner, J., Lee, G., Joester, J., Lynch, M., Barnes, E. H., Wrigley, P. J., & Ng, K. (2015). Thermal quantitative sensory testing: a study of 101 control subjects. Journal of Clinical Neuroscience, 22(3), 588-591. [2] Blankenburg, M., Boekens, H., Hechler, T., Maier, C., Krumova, E., Scherens, A., … & Zernikow, B. (2010). Reference values for quantitative sensory testing in children and adolescents: developmental and gender differences of somatosensory perception. PAIN®, 149(1), 76-88. [3]Yarnitsky, D., & Sprecher, E. (1994). Thermal testing: normative data and repeatability for various test algorithms. Journal of the neurological sciences, 125(1), 39-45. [4] Sampaio, F. A., Sampaio, C. R., Cunha, C. O., Costa, Y. M., Alencar, P. N., Bonjardim, L. R., … & Conti, P. C. (2019). The effect of orthodontic separator and short‐term fixed orthodontic appliance on inflammatory mediators and somatosensory function. Journal of oral rehabilitation, 46(3), 257-267. [5] Yang, Q., Dorado, R., Chaya, C., & Hort, J. (2018). The impact of PROP and thermal taster status on the emotional response to beer. Food Quality and Preference, 68, 420-430. [6] Hainsworth, K. R., Simpson, P. M., Ali, O., Varadarajan, J., Rusy, L., & Weisman, S. J. (2020). Quantitative Sensory Testing in Adolescents with Co-occurring Chronic Pain and Obesity: A Pilot Study. Children, 7(6), 55. [7] Rosner, J., Hostettler, P., Scheuren, P. S., Sirucek, L., Rinert, J., Curt, A., … & Hubli, M. (2018). Normative data of contact heat evoked potentials from the lower extremities. Scientific reports, 8(1), 1-9. [8] Jutzeler, C. R., Rosner, J., Rinert, J., Kramer, J. L., & Curt, A. (2016). Normative data for the segmental acquisition of contact heat evoked potentials in cervical dermatomes. Scientific reports, 6, 34660. [9] Granovsky, Y., Anand, P., Nakae, A., Nascimento, O., Smith, B., Sprecher, E., & Valls-Solé, J. (2016). Normative data for Aδ contact heat evoked potentials in adult population: a multicenter study. Pain, 157(5), 1156-1163. [10]Hüllemann, P., Nerdal, A., Binder, A., Helfert, S., Reimer, M., & Baron, R. (2016). Cold‐evoked potentials–Ready for clinical use?. European Journal of Pain, 20(10), 1730-1740. [11]Staud, R., Weyl, E. E., Riley III, J. L., & Fillingim, R. B. (2014). Slow temporal summation of pain for assessment of central pain sensitivity and clinical pain of fibromyalgia patients. PloS one, 9(2), e89086. [12]Bar-Shalita, T., Vatine, J. J., Yarnitsky, D., Parush, S., & Weissman-Fogel, I. (2014). Atypical central pain processing in sensory modulation disorder: absence of temporal summation and higher after-sensation. Experimental brain research, 232(2), 587-595. [13] Elman, I., Upadhyay, J., Langleben, D. D., Albanese, M., Becerra, L., & Borsook, D. (2018). Reward and aversion processing in patients with post-traumatic stress disorder: functional neuroimaging with visual and thermal stimuli. Translational psychiatry, 8(1), 1-15. [14] Harrison, R., Zeidan, F., Kitsaras, G., Ozcelik, D., & Salomons, T. V. (2019). Trait mindfulness is associated with lower pain reactivity and connectivity of the default mode network. The Journal of Pain, 20(6), 645-654. [15]Russo, A., Tessitore, A., Esposito, F., Di Nardo, F., Silvestro, M., Trojsi, F., … & Tedeschi, G. (2017). Functional changes of the perigenual part of the anterior cingulate cortex after external trigeminal neurostimulation in migraine patients. Frontiers in neurology, 8, 282. [16] Grahl, A., Onat, S., & Büchel, C. (2018). The periaqueductal gray and Bayesian integration in placebo analgesia. Elife, 7, e32930 [17] Baad-Hansen, L., Lu, S., Kemppainen, P., List, T., Zhang, Z., & Svensson, P. (2015). Differential changes in gingival somatosensory sensitivity after painful electrical tooth stimulation. Experimental Brain Research, 233(4), 1109-1118 [18] Rahal, V., Gallinari, M. D. O., Barbosa, J. S., Martins-Junior, R. L., Santos, P. H. D., Cintra, L. T. A., & Briso, A. L. F. (2018). Influence of skin cold sensation threshold in the occurrence of dental sensitivity during dental bleaching: a placebo controlled clinical trial. Journal of Applied Oral Science, 26. [19] Mo, X., Zhang, J., Fan, Y., Svensson, P., & Wang, K. (2015). Thermal and mechanical quantitative sensory testing in chinese patients with burning mouth syndrome–a probable neuropathic pain condition?. The journal of headache and pain, 16(1), 84. [20] Gruenwald, I., Mustafa, S., Gartman, I., & Lowenstein, L. (2015). Genital sensation in women with pelvic organ prolapse. International urogynecology journal, 26(7), 981-984. [21]Reed, B. D., Sen, A., Harlow, S. D., Haefner, H. K., & Gracely, R. H. (2017). Multimodal vulvar and peripheral sensitivity among women with vulvodynia: a case-control study. Journal of lower genital tract disease, 21(1), 78. [22] Lesma, A., Bocciardi, A., Corti, S., Chiumello, G., Rigatti, P., & Montorsi, F. (2014). Sexual function in adult life following Passerini-Glazel feminizing genitoplasty in patients with congenital adrenal hyperplasia. The Journal of urology, 191(1), 206-211. [23] Chen, X., Wang, F. X., Hu, C., Yang, N. Q., & Dai, J. C. (2018). Penile sensory thresholds in subtypes of premature ejaculation: implications of comorbid erectile dysfunction. Asian journal of andrology, 20(4), 330.

BESA statistics

BESA Statistics 2.1 released!

The successor to the ground-breaking BESA Statistics program is there! BESA Statistics 2.1 greatly enhances the options of the previous version 2.0. As before, dedicated workflows allow you to perform t-test, one-way ANOVA, and correlation analyses of your data using the parameter-free cluster permutation statistics which so elegantly solve the multiple-test problem. We have added several input data types to this pipeline, in order to ensure that time-frequency analyses and connectivity analyses are now fully supported.

The main highlights of the new release are:

  • In all workflows, the data type Connectivity can now be used. This enables direct import of results obtained by BESA Connectivity for group statistics on connectivity results in sensor space or source space.
  • For Image data, a configurable slice view is available that displays sequences in one of three available orthogonal orientation.
  • The color theme can be adjusted between BESA White and the previous BESA Standard.
  • Several new color maps are available.
  • The data values are displayed on mouse-over in the detail windows.
  • Time-frequency data stored by BESA Connectivity with wavelet analysis can now be read with the correct (logarithmic) frequency spacing.
  • Single-trial time-frequency data can now be read in the t-test workflow (.tfcs data format).
  • There is no upper limit on the number of data files imported into the workflow.
  • A new image export format is available (.svg).
  • Screenshots and cluster summary results can now be copied to the clipboard using the right mouse popup menu.
Medoc TSA2 QST

New CHEPS for TSA 2 – Fast. Precise. Easy.

Advanced Thermosensory Stimulator  (TSA)

  • Precise stimulation temperature control.
  • External Control programming capability.
  • Rapid thermal stimulation rates- up to 13°C/sec.
  • Single and Dual Thermode configurations.
  • Upgradeable for the fMRI imaging environment.
  • Add the new CHEPS for TSA 2 thermode for rapid and precise heat and cold stimulation.
Carbon Wire Loops for MR EEG

State of the art MR artifact handling with Carbon Wire Loops – a true market innovation!

HIgh Density RNet

Update to the R-Net – high-density montage including face and neck electrodes

BrainVision Analyser

BrainVision Analyzer 2.2.1 – Integration of Tobii Pro Lab data in Add Channels & more

Simultaneous TMS & EEG

Methodology for characterizing network activations with neuro-navigated TMS and EEG

wireless stimtracker

Wireless Triggering Now Available

Melbourne Visit 2020

Feasibility of an Ambulatory HD EEG system for Home Monitoring in Epilepsy Patients

Motor neuroprosthesis implanted with neurointerventional surgery improves capacity for activities of daily living tasks in severe paralysis


Background Implantable brain–computer interfaces (BCIs), functioning as motor neuroprostheses, have the potential to restore voluntary motor impulses to control digital devices and improve functional independence in patients with severe paralysis due to brain, spinal cord, peripheral nerve or muscle dysfunction. However, reports to date have had limited clinical translation.

Methods Two participants with amyotrophic lateral sclerosis (ALS) underwent implant in a single-arm, open-label, prospective, early feasibility study. Using a minimally invasive neurointervention procedure, a novel endovascular Stentrode BCI was implanted in the superior sagittal sinus adjacent to primary motor cortex. The participants undertook machine-learning-assisted training to use wirelessly transmitted electrocorticography signal associated with attempted movements to control multiple mouse-click actions, including zoom and left-click. Used in combination with an eye-tracker for cursor navigation, participants achieved Windows 10 operating system control to conduct instrumental activities of daily living (IADL) tasks.

Results Unsupervised home use commenced from day 86 onwards for participant 1, and day 71 for participant 2. Participant 1 achieved a typing task average click selection accuracy of 92.63% (100.00%, 87.50%–100.00%) (trial mean (median, Q1–Q3)) at a rate of 13.81 (13.44, 10.96–16.09) correct characters per minute (CCPM) with predictive text disabled. Participant 2 achieved an average click selection accuracy of 93.18% (100.00%, 88.19%–100.00%) at 20.10 (17.73, 12.27–26.50) CCPM. Completion of IADL tasks including text messaging, online shopping and managing finances independently was demonstrated in both participants.

Conclusion We describe the first-in-human experience of a minimally invasive, fully implanted, wireless, ambulatory motor neuroprosthesis using an endovascular stent-electrode array to transmit electrocorticography signals from the motor cortex for multiple command control of digital devices in two participants with flaccid upper limb paralysis.


The latest Spike2 updates for V10, V9 and V8, for Windows is available now

Features of version 10.07 include:

  • Video recording has a new option to fix timing problems with some cameras. It now compensates for time delays when starting to record video. It also can be used across a remote desktop. Video review has frame accurate video stepping for both MP4 and AVI files.
  • You can display axes in the data area of Time, Result and XY views. This is expected to be useful when generating figures for publication
  • In a time view you can add channels without a y axis to a group (as long as the group head has an axis). This allows you to colour the background of areas of a waveform with states and to superimpose TextMark data.
  • Many useful small improvements and fixes

“It’s so Cute I Could Crush It!”: Understanding Neural Mechanisms of Cute Aggression

  • Graduate School of Education, University of California, Riverside, Riverside, CA, United States

The urge people get to squeeze or bite cute things, albeit without desire to cause harm, is known as “cute aggression.” Using electrophysiology (ERP), we measured components related to emotional salience and reward processing. Participants aged 18–40 years (n = 54) saw four sets of images: cute babies, less cute babies, cute (baby) animals, and less cute (adult) animals. On measures of cute aggression, feeling overwhelmed by positive emotions, approachability, appraisal of cuteness, and feelings of caretaking, participants rated more cute animals significantly higher than less cute animals.

There were significant correlations between participants’ self-report of behaviors related to cute aggression and ratings of cute aggression in the current study.

N200: A significant effect of “cuteness” was observed for animals such that a larger N200 was elicited after more versus less cute animals. A significant correlation between N200 amplitude and the tendency to express positive emotions in a dimorphous manner (e.g., crying when happy) was observed.

RewP: For animals and babies separately, we subtracted the less cute condition from the more cute condition. A significant correlation was observed between RewP amplitude to cute animals and ratings of cute aggression toward cute animals. RewP amplitude was used in mediation models.

Mediation Models: Using PROCESS (Hayes, 2018), mediation models were run. For both animals and babies, the relationship between appraisal and cute aggression was significantly mediated by feeling overwhelmed. For cute animals, the relationship between N200 amplitude and cute aggression was significantly mediated by feeling overwhelmed. For cute animals, there was significant serial mediation for RewP amplitude through caretaking, to feeling overwhelmed, to cute aggression, and RewP amplitude through appraisal, to feeling overwhelmed, to cute aggression. Our results indicate that feelings of cute aggression relate to feeling overwhelmed and feelings of caretaking. In terms of neural mechanisms, cute aggression is related to both reward processing and emotional salience.


Cute aggression is defined as the urge some people get to squeeze, crush, or bite cute things, albeit without any desire to cause harm. Aragón et al. (2015) initially operationalized the phenomenon of “cute aggression” through individual self-reports while viewing cute stimuli. The authors investigated cute aggression using pictures of baby humans and animals via an online survey. Findings indicated that for infantile babies (e.g., images that had been altered to have large eyes and chubby cheeks; Sherman et al., 2013) and baby animals, there was a relationship between being overwhelmed by positive feelings and the expression of cute aggression (Aragón et al., 2015).

Acute Exercise as an Intervention to Trigger Motor Performance and EEG Beta Activity in Older Adults

Anodal transcranial patterned stimulation of the motor cortex during gait can induce activity-dependent corticospinal plasticity to alter human gait

State Anxiety Down-Regulates Empathic Responses: Electrophysiological Evidence

Age-Related Alterations in Electroencephalography Connectivity and Network Topology During n-Back Working Memory Task