Test Stimuli Research Articles

Sound quality modelling of hairdryer noise

The demand for acoustic comfort in domestic appliances increases with the rapid growth of living quality requirements. As a common domestic appliance, the hairdryer produces unwanted noise that affects comfort during working. Manufacturers make great efforts to control the hairdryer noise, e.g., reduce the sound pressure level (SPL) by increasing blades number to make the frequency of noise energy above the hearing range. This study investigated the noise discomfort of a supersonic hairdryer (SHD) and three standard hairdryers (HD). We measured and recorded hairdryer noise at all operating conditions, and generated 120 test stimuli at SPLs ranging from 60 to 72 dB(A) in 3 dB steps based on 24 sound samples. Twenty-four subjects evaluated the noise discomfort of all stimuli using the absolute magnitude estimation (AME) method. The contribution of psychoacoustic metrics, i.e. loudness, sharpness, roughness, fluctuation strength, tonality (hearing model) and articulation index, to the noise discomfort was analysed by partial correlation analysis. Hairdryer noise discomfort was dominated by loudness and significantly influenced by tonality. The sound quality models were established for SHD and HD by multiple linear regression between the discomfort and two psychoacoustic metrics, i.e., loudness and tonality. The SHD performed better in sound quality for less discomfort and interference of communication than the HD, yet the adverse effects of the ultra-high frequencies on comfort and health need further consideration.

Threat belief determines the degree of costly safety behavior: Assessing rule-based generalization of safety behavior with a dimensional measure of avoidance

Excessive generalization of safety behavior to innocuous stimuli that resemble a feared stimulus is oftentimes pathological especially with inflicted impairments. Safety behavior is conventionally assessed dichotomously, requiring multiple presentations of each test stimulus for assessing the proportion of safety behavior executed. Thus, the generalization gradient confounds with ongoing extinction learning during non-reinforced test trials. The present study employed a recently developed dimensional measure of avoidance to examine the extent of safety behavior generalization. We found that a dimensional measure of avoidance was able to assess the generalization gradients of safety behavior even when each test stimulus was presented once, thus minimizing the effect of ongoing extinction learning. Of equal importance is whether higher-order cognitive processes shape generalization of safety behavior. We found a range of distinct generalization gradients in safety behavior, which were highly consistent with participants’ verbally reported relational rules. This rule-based generalization parallels to how clinically anxious individuals develop different threat beliefs after trauma exposure, and models how these distinct threat beliefs determine the extent of safety behavior engagement.

Luminance dependency of perceived color shift after color contrast adaptation caused by higher-order color channels.

Color adaptation is a phenomenon in which, after prolonged exposure to a specific color (i.e. adaptation color), the perceived color shifts to approximately the opposite color direction of the adaptation color. Color adaptation is strongly related to sensitivity changes in photoreceptors, such as von Kries adaptation and cone-opponent mechanisms. On the other hand, the perceptual contrast of colors (e.g. perceptual saturation of the red-green direction) decreases after adaptation to a stimulus with spatial and/or temporal color modulation along the color direction. This phenomenon is referred to as color contrast adaptation. Color contrast adaptation has been used to investigate the representation of colors in the visual system. In the present study, we measured color perception after color contrast adaptation to stimuli with temporal color modulations along complicated color loci in a luminance-chromaticity plane. We found that, after the observers adapted to color modulations with different chromaticities at higher, medium, and lower luminance (e.g. temporal alternations among red, green, and red, each at a different luminance level), the chromaticity corresponding to perceptual achromaticity (the achromatic point) shifted to the same color direction as the adaptation chromaticity in each test stimulus luminance. In contrast, this luminance dependence of the achromatic point shift was not observed after adaptation to color modulations with more complex luminance-chromaticity correspondences (e.g. alternating red, green, red, green, and red, at five luminance levels, respectively). In addition, the occurrence or nonoccurrence of the luminance-dependent achromatic point shift was qualitatively predicted using a noncardinal model composed of channels preferring intermediate color directions between the cardinal chromaticity and luminance axes. These results suggest that the noncardinal channels are involved in the luminance-dependent perceived color shift after adaptation.

Temporal Summation in Fibromyalgia Patients: Comparing Phasic and Tonic Paradigms.

IntroductionFibromyalgia (FM) is associated with dysfunctional pain modulation mechanisms, including central sensitization. Experimental pain measurements, such as temporal summation (TS), could serve as markers of central sensitization and have been previously studied in these patients, with conflicting results. Our objective in this study was to explore the relationships between two different protocols of TS (phasic and tonic) and test the associations between these measures and other clinical variables.Materials and MethodsIn this cross-sectional analysis of a randomized clinical trial, patients were instructed to determine their pain-60 test temperature, then received one train of 15 repetitive heat stimuli and rated their pain after the 1st and 15th stimuli: TSPS-phasic was calculated as the difference between those. We also administered a tonic heat test stimulus at the same temperature continuously for 30 s and asked them to rate their pain levels after 10 s and 30 s, calculating TSPS-tonic as the difference between them. We also collected baseline demographic data and behavioral questionnaires assessing pain, depression, fatigue, anxiety, sleepiness, and quality of life. We performed univariable analyses of the relationship between TSPS-phasic and TSPS-tonic, and between each of those measures and the demographic and clinical variables collected at baseline. We then built multivariable linear regression models to find predictors for TSPS-phasic and TSPS-tonic, while including potential confounders and avoiding collinearity.ResultsFifty-two FM patients were analyzed. 28.85% developed summation during the TSPS-phasic protocol while 21.15% developed summation during the TSPS-tonic protocol. There were no variables associated TSPS phasic or tonic in the univariable analyses and both measures were not correlated. On the multivariate model for the TSPS-phasic protocol, we found a weak association with pain variables. BPI-pain subscale was associated with more temporal summation in the phasic protocol (ß = 0.38, p = 0.029), while VAS for pain was associated with less summation in the TSPS-tonic protocol (ß = −0.5, p = 0.009).ConclusionOur results suggest that, using heat stimuli with pain-60 temperatures, a TSPS-phasic protocol and a TSPS-tonic protocol are not correlated and could index different neural responses in FM subjects. Further studies with larger sample sizes would be needed to elucidate whether such responses could help differentiating subjects with FM into specific phenotypes.

Diffuse noxious inhibitory controls and conditioned pain modulation: a shared neurobiology within the descending pain inhibitory system?

Diffuse noxious inhibitory controls and conditioned pain modulation: a shared neurobiology within the descending pain inhibitory system?

Basolateral amygdala cannabinoid CB1 receptors mediate the antinociceptive activity of harmaline in adolescent male mice

Evidence suggests a clear role for the amygdala endocannabinoid system in pain processing. Harmaline has been also known as the main nociceptive agent extracted from the Peganum harmala plant. In this study, the role of basolateral amygdala (BLA) cannabinoid CB1 receptors in pain sensitivity of harmaline-treated mice were assessed using tail-flick and hot plate methods in adolescent male NMRI mice. Intraperitoneal administration of two higher doses of harmaline (6 and 8 mg/kg) increased tail-flick latency, suggesting an antinociceptive activity. The same result was observed for the higher dose of harmaline in the hot plate test. Intra-BLA microinjection of CB1 receptor agonist ACPA (1 and 1.5 ng/mouse) or (1.5 ng/mouse) enhanced the ineffective dose-response of harmaline on pain threshold in the tail-flick or hot plate tests, respectively. Microinjection of two higher doses of CB1 receptor antagonist AM251 (0.5 and 1 ng/mouse) attenuated the antinociceptive activity of harmaline (8 ng/mouse) in both tail-flick and hot plate tests. Meanwhile, ACPA and AM251 did not alter latency to withdraw from the noxious stimulus in both tests, by themselves. It should be noted that the analgesic dose of the drugs alone or in combination did not affect locomotor activity. The obtained results highlight that BLA CB1 receptors mediate the antinociceptive activity of harmaline.

Prepulse Inhibition and P50 Suppression in Relation to Creativity and Attention: Dispersed Attention Beneficial to Quantitative but Not Qualitative Measures of Divergent Thinking

The current study investigated whether lower sensory and sensorimotor gating were related to higher levels of creativity and/or attentional difficulties in a natural population of primary school children (9- to 13-year-old). Gating abilities were measured with P50 suppression and prepulse inhibition of the startle reflex (PPI). The final sample included 65 participants in the P50 analyses and 37 participants in the PPI analyses. Our results showed that children with a high P50 amplitude to testing stimuli scored significantly higher on the divergent outcome measures of fluency and flexibility but not originality compared to children with a lower amplitude. No significant differences were found on any of the creativity measures when the sample was split on average PPI parameters. No significant differences in attention, as measured with a parent questionnaire, were found between children with low or high levels of sensory or sensorimotor gating. The data suggest that quantitative, but not qualitative measures of divergent thinking benefit from lower psychophysiological gating and that attentional difficulties stem from specific instead of general gating deficits. Future studies should take the effect of controlled attention into consideration.

Acoustic Change Complex Evoked by Horizontal Sound Location Change in Young Adults With Normal Hearing.

Acoustic change complex (ACC) is a cortical auditory-evoked potential induced by a change of continuous sound stimulation. This study aimed to explore: (1) whether the change of horizontal sound location can elicit ACC; (2) the relationship between the change of sound location and the amplitude or latency of ACC; (3) the relationship between the behavioral measure of localization, minimum audible angle (MAA), and ACC. A total of 36 normal-hearing adults participated in this study. A 180° horizontal arc-shaped bracket with a 1.2 m radius was set in a sound field where participants sat at the center. MAA was measured in a two-alternative forced-choice setting. The objective electroencephalography recording of ACC was conducted with the location changed at four sets of positions, ±45°, ±15°, ±5°, and ±2°. The test stimulus was a 125–6,000 Hz broadband noise of 1 s at 60 ± 2 dB SPL with a 2 s interval. The N1′–P2′ amplitudes, N1′ latencies, and P2′ latencies of ACC under four positions were evaluated. The influence of electrode sites and the direction of sound position change on ACC waveform was analyzed with analysis of variance. Results suggested that (1) ACC can be elicited successfully by changing the horizontal sound location position. The elicitation rate of ACC increased with the increase of location change. (2) N1′–P2′ amplitude increased and N1′ and P2′ latencies decreased as the change of sound location increased. The effects of test angles on N1′–P2′ amplitude [F(1.91,238.1) = 97.172, p < 0.001], N1′ latency [F(1.78,221.90) = 96.96, p < 0.001], and P2′ latency [F(1.87,233.11) = 79.97, p < 0.001] showed a statistical significance. (3) The direction of sound location change had no significant effect on any of the ACC peak amplitudes or latencies. (4) Sound location discrimination threshold by the ACC test (97.0% elicitation rate at ±5°) was higher than MAA threshold (2.08 ± 0.5°). The current study results show that though the ACC thresholds are higher than the behavioral thresholds on MAA task, ACC can be used as an objective method to evaluate sound localization ability. This article discusses the implications of this research for clinical practice and evaluation of localization skills, especially for children.

Conditioned pain modulation is not associated with thermal pain illusion.

Paradoxical sensations, known as thermal pain illusions, can be evoked by painful cold-heat pulse stimulation. They may provide diagnostic value; however, the possible interaction between conditioned pain modulation and thermal pain illusions has not been explored. The present study examined: (1) whether conditioned pain modulation could be induced by alternating tonic painful cold-heat pulse stimulation; and (2) whether the presence of thermal pain illusions during the conditioning stimulus influences the degree of conditioned pain modulation. This study was approved by the Ethics Committee of Meikai University (A1507). Conditioned pain modulation was provoked using alternating painful cold-heat pulses delivered at 20-s intervals applied to the forearm. Thermal pain illusions were qualitatively evaluated, and conditioned pain modulation was assessed quantitatively using the pressure pain threshold as a test stimulus. Differences in the conditioned pain modulation effect between the participants who experienced thermal pain illusions and those who did not were analysed using Student's t-test. A significant positive conditioned pain modulation effect (51.0±4.7%, overall effect) was detected. There was no significant difference in conditioned pain modulation between the participants who experienced thermal pain illusions and those who did not (44.3±6.0% and 55.5±6.8%, respectively; p=0.255). Conditioned pain modulation induced by alternating painful conditioning cold-heat pulse stimulation was identical during the conditioning stimulation in volunteers with and without thermal pain illusions. Conditioning cold-heat pulse stimulation is useful to evaluate conditioned pain modulation. Moreover, conditioned pain modulation is not influenced by the presence of thermal pain illusions, indicating partially different underlying supraspinal, neuronal networks.

Exploring pain mechanisms in hypermobile Ehlers-Danlos syndrome: A case-control study.

The hypermobile type of Ehlers-Danlos syndrome (hEDS) is a heritable connective tissue disorder, associated with joint hypermobility and prominent chronic pain. Because experimental pain testing in hEDS is scarce, the underlying mechanisms are still poorly understood. The present study assesses endogenous pain facilitation and pain inhibition in hEDS, using a protocol for temporal summation of pain (TSP), conditioned pain modulation (CPM) and exercise-induced hypoalgesia (EIH). Twenty women with hEDS and 20 age-matched healthy controls participated. After evaluating thermal and mechanical pain thresholds (PPT), TSP was assessed using 10 repetitive painful pressure stimuli. CPM was provoked using pressure as the test stimulus and hand immersion in hot water (46°) as the conditioning stimulus. EIH was assessed after a submaximal cycling protocol. The hEDS group demonstrated reduced PPTs and showed significantly more TSP after repeated painful stimuli than the control group. In comparison to the healthy control group, the hEDS group demonstrated significantly less EIH at the quadriceps test location. At the trapezius, EIH did not significantly differ between groups. No significant differences were found between the hEDS group and control group in the CPM response. The results demonstrate increased TSP in hEDS, suggesting increased central pain facilitation. EIH should be studied more extensively but may be disturbed when evaluated in the muscles that are activated during exercise. The CPM results are inconclusive and require more research. Studies regarding the mechanisms that underlie pain in hEDS are scarce, although it is the most prevalent and disabling symptom in this patient population. This study demonstrates increased temporal summation in hEDS and suggests that exercise-induced hypoalgesia may be reduced. Because exercise is a cornerstone in the multidisciplinary treatment of heritable connective tissue disorders, gaining knowledge in this field is important. Pressure stimuli were used to facilitate the international usability of the protocols, allowing for future data acquisition in large cohorts.

The Contribution of Psychological Factors to Inter-Individual Variability in Conditioned Pain Modulation Is Limited in Young Healthy Subjects.

Conditioned pain modulation (CPM) describes the decrease in pain perception of a test stimulus (TS) when presented together with a heterotopic painful conditioning stimulus (CS). Inter-individual differences in CPM are large and have been suggested to reflect differences in endogenous pain modulation. In a previous analysis, we demonstrated that in young, healthy participants, inter-individual differences account for about one-third of CPM variance, with age and sex together explaining only 1%. Here, we investigated if psychological factors explain significant amounts of inter-individual variance in CPM. Using the same dataset as before, we performed both cross-sectional (n = 126) and repeated measures (n = 52, 118 observations) analysis and the corresponding variance decompositions, using results of psychological questionnaires assessing depression, trait anxiety and pain catastrophizing. Psychological factors did not significantly predict CPM magnitude, neither directly nor when interactions with the CPM paradigm were assessed; however, the interaction between depression and the paradigm approached significance. Variance decomposition showed that the interaction between depression and the CPM paradigm explained an appreciable amount of variance (3.0%), but this proportion seems small when compared to the residual inter-individual differences (35.4%). The main effects of the psychological factors and the interactions of anxiety or catastrophizing with the CPM paradigm are explained at <0.1% each. These results show that the contribution of psychological factors to inter-individual CPM differences in healthy participants is limited and that the large inter-individual variability in the CPM effect remains largely unexplained.

Effect of observer age and stimulus size on the performance of CIE color matching functions.

Both observer age and size of stimulus as characterized using the field of view (FOV) are two important parameters to affect the color matching functions (CMFs) of human observers. They are also included in the cone fundamental and CMFs models that were recently proposed by the International Commission on Illumination (CIE) in 2006. In contrast to the great number of studies investigating the performance of CMFs in characterizing color matches and mismatches using different primary sets, few study investigated the effect of CMFs in characterizing these two factors. In this study, we carefully designed a series of test stimuli in five colors, which had different magnitudes of calculated color difference to the corresponding reference stimulus using the CIE 2006 CMFs model. The stimuli were presented in two FOVs (i.e., 8.6° and 2.9°). A group of young and senior observers were asked to judge which of the two test stimuli appeared to be similar to the reference stimulus, which was a forced choice. The color differences calculated using the CIE 1931 2° and 1964 10° CMFs were found to have higher correlations to the visual color differences judged by the senior and young observers respectively, regardless of the actual FOVs used in the experiment. In addition, though the CIE 2006 CMFs with the different parameter settings always had better performance in predicting the perceived color differences, they failed to characterize the effect of observer age and stimulus size. Also, the experiment results did not support the CIE's recommendation of using the 10° CMFs for stimuli with an FOV greater than 4° and the 2° CMFs for those smaller than 4°.

Effect of Sensory Sensitivity on Pain Processing Following Noxious Electrical Stimulation in Healthy Participants

The purpose of this study was to investigate the influence of sensitivity to sensory input, including pain, on the conditioned pain modulation (CPM) effect of oxious Electrical Stimulation (NxES). Seventeen healthy participants (24.8 (+/- 2) years) were enrolled in this study that was approved by the IRB. Each person participated in a familiarization session, and 2 testing sessions 24 hours apart. Sensory sensitivity was assessed with the Sensory Hypersensitivity Scale, touch and heat/cold detection thresholds. Pain sensitivity was assessed with the Pain Sensitivity Questionnaire, heat/cold pain thresholds, and pressure pain threshold (PPT). Pain modulation was assessed with temporal summation (TS) and CPM involved a test stimulus of PPT and conditioning stimulus was immersion in a cold water bath for 2 min. The NxES: 20 min of electrical stimulation (400 μs pulse duration, 50 pulses/s; 10s on:10s off; intensity was maximum tolerated). The difference between PPT before and after the NxES comprised the treatment effect. Neither Sensitivity to touch or temperature sensations nor pain sensitivity related to the treatment effect of the NxES. A higher the amplitude of pain perception of NxES was associated with greater treatment effect. The NxES was effective in inhibiting pain and reduced the extent of pain facilitation 24 hours after the treatment. CPM was no different after the NxES. The finding suggests that people who are more sensitive to sensations also experience pain inhibition from NxES. The nervous system is not as “reactive” to pain after a treatment of NxES and the lack of change in the CPM after the treatment of NXES suggests that artificially inducing pain inhibition with NXES does not interfere with the normal pain inhibitory function of the nervous system. Thus, any inhibition due to NXES treatment could augment that which is produced by a patient's own nervous system. The purpose of this study was to investigate the influence of sensitivity to sensory input, including pain, on the conditioned pain modulation (CPM) effect of oxious Electrical Stimulation (NxES). Seventeen healthy participants (24.8 (+/- 2) years) were enrolled in this study that was approved by the IRB. Each person participated in a familiarization session, and 2 testing sessions 24 hours apart. Sensory sensitivity was assessed with the Sensory Hypersensitivity Scale, touch and heat/cold detection thresholds. Pain sensitivity was assessed with the Pain Sensitivity Questionnaire, heat/cold pain thresholds, and pressure pain threshold (PPT). Pain modulation was assessed with temporal summation (TS) and CPM involved a test stimulus of PPT and conditioning stimulus was immersion in a cold water bath for 2 min. The NxES: 20 min of electrical stimulation (400 μs pulse duration, 50 pulses/s; 10s on:10s off; intensity was maximum tolerated). The difference between PPT before and after the NxES comprised the treatment effect. Neither Sensitivity to touch or temperature sensations nor pain sensitivity related to the treatment effect of the NxES. A higher the amplitude of pain perception of NxES was associated with greater treatment effect. The NxES was effective in inhibiting pain and reduced the extent of pain facilitation 24 hours after the treatment. CPM was no different after the NxES. The finding suggests that people who are more sensitive to sensations also experience pain inhibition from NxES. The nervous system is not as “reactive” to pain after a treatment of NxES and the lack of change in the CPM after the treatment of NXES suggests that artificially inducing pain inhibition with NXES does not interfere with the normal pain inhibitory function of the nervous system. Thus, any inhibition due to NXES treatment could augment that which is produced by a patient's own nervous system.

Investigation of the posterior parietal cortex to ventral premotor connection in writer's cramp using transcranial magnetic stimulation.

The posterior parietal, premotor and motor cortices are brain regions relevant in the planning of movement. Previous transcranial magnetic stimulation (TMS) studies have shown ipsilateral premotor-to-motor inhibition in healthy subjects at rest. This premotor-to-motor inhibition has been found to be altered in patients with writer's cramp (WC), a common type of focal hand dystonia. We aimed to investigate the influence of the posterior parietal cortex on the ipsilateral ventral premotor cortex using a three single-pulse TMS paradigm. Nineteen right-handed subjects (eleven healthy volunteers and eight WC patients) completed the study. A three single-pulse TMS paradigm (preconditioning, conditioning, and test stimuli) was used to sequentially stimulate the left posterior parietal, ventral premotor, and primary motor cortices. We found that in both healthy subjects and patients, stimulating the ipsilateral posterior parietal cortex resulted in reversal of the resting premotor-to-motor inhibition. Resting premotor-to-motor inhibition was also found, with no statistically significant group difference. Furthermore, a facilitatory effect of the posterior parietal cortex on the primary motor cortex was found in both groups. Our results suggest that in the resting state, the inhibitory effect of the left posterior parietal cortex on the ipsilateral ventral premotor cortex found in healthy subjects is also intact in WC patients. While we are unable to identify any parietal-to-premotor connectivity abnormality in the resting state, an abnormality during a specific task cannot be excluded. Previously reported conductivity abnormalities in resting fMRIdo not appear to translate into a TMS physiological abnormality.

Adaptive design optimization for a Mnemonic Similarity Task

The Mnemonic Similarity Task (MST: Stark et al., 2019) is a modified recognition memory task designed to place strong demand on pattern separation. The sensitivity and reliability of the MST make it an extremely valuable tool in clinical settings, where it has been used to identify hippocampal dysfunction associated with healthy aging, dementia, schizophrenia, depression, and other disorders. As with any test used in a clinical setting, it is especially important for the MST to be administered as efficiently as possible. We apply adaptive design optimization methods (Lesmes et al.,2015; Myung et al., 2013) to optimize the presentation of test stimuli in accordance with previous responses. This optimization is based on a signal detection model of an individual’s memory capabilities and decision-making processes. We demonstrate that the adaptive design optimization approach generally reduces the number of test stimuli needed to measure recognition memory.

Catechol-O-methyltransferase (COMT) Val158Met Polymorphism and Prepulse Inhibition of the Change-related Cerebral Response

Change-related potentials elicited by an abrupt sound feature's change are attenuated by a leading weak sound (prepulse inhibition: PPI). We investigated whether the PPI index is associated with the catechol-methyltransferase (COMT) Val158Met polymorphism (rs4680), which is involved in the metabolism of dopamine in the prefrontal cortex. Healthy subjects with normal hearing were recruited (n = 70). A train of 100-Hz clicks 650 ms in duration was used. The test stimulus was an abrupt increase in sound intensity (+10 dB) from the baseline (70 dB) provided at 400 ms after the sound onset. Three consecutive clicks at 30, 40, and 50 ms before the change's onset were greater (+3 or +5 dB) from the baseline as a prepulse. The targeting auditory evoked potential component was Change-N1 peaking approx. 130 ms after the change onset. We calculated the inhibition level as the% inhibition of the Change-N1 amplitude by a prepulse. The %PPI in the Met-carriers was significantly greater than that in the Val/Val-individuals. Our results suggest that dopamine might play a role in the PPI of the change-related response. We propose that this index has the potential to identify an intermediate phenotype in psychiatric disorders such as schizophrenia.

P 17 Posttraumatic Headache – Pain Related Evoked Potentials (PREP) and Conditioned Pain Modulation (CPM) as possible biomarkers for identification of risk patients

Introduction : Posttraumatic headache (PTH) is one of the most common complications following traumatic brain injury (TBI)[1], though its underlying pathomechanisms have not been fully understood yet. An altered descending pain modulation seems to contribute to its development and persistence[2]. The aim of our study was to examine the pain processing in PTH-patients using pain-related evoked potentials after electrical stimulation (PREP) and conditioned pain modulation (CPM), based on their N1P1-amplitude as an objective readout. We chose a longitudinal design to analyse if PREP and CPM can be used as biomarkers for persisting PTH. Methods : We plan to recruit 30 patients with PTH and 20 healthy control subjects. Currently (October 2021) we have recruited 21 PTH-patients and 19 healthy control subjects. The patients were invited for follow-up sessions at 3 and 6 months after inclusion. The painful stimuli were applied at the dorsum of the right hand and above the right eyebrow with a concentric surface electrode while PREP were recorded over Cz and evoked pain was assessed on the numerical rating scale (NRS), as previously described [3]. For CPM we used the same electrode for painful cutaneous electric stimulation on the right hand as the test stimulus and the immersion of the left hand in a 10°C cold water bath as the conditioning stimulus. With the assessed data we calculated early and late CPM-effects for the subjective pain ratings and the objective N1-P1-amplitudes in the EEG, as recently reported[4]. Results : PTH-patients were on average 41.3 (± 10.7) years old, had a mean headache duration of 103 (± 265) weeks and a mean headache intensity of 5.9 (± 1.9) on the NRS (0-10). We currently present data at baseline. PREP parameters in both regions did not differ between PTH-patients and age-matched controls. The early CPM-effect based on PREP-amplitudes and the late CPM effect based on pain-rating were significantly less pronounced in patients than in controls. The early and late CPM effect for pain and amplitudes correlated significantly in both groups, but no significant correlation comparing CPM effects based on pain with the CPM effects based on amplitudes could be detected. Conclusions : Our preliminary results display a deficient endogenous pain modulation in PTH-patients also based on PREP-amplitude as an objective readout. The missing correlation between CPM-effects based on subjective pain ratings and PREP-amplitudes indicate different pathways involved in nociception and subjective pain perception. Further analysis of subgroups is planned after complete recruitment.

Adaptation effects along a voice/non-voice continuum

Adaptation, the selective decrease in neural responses following repeated stimulation, is likely important for perception in the face of variable sensory input. Previous researchers have observed contrastive adaptation effects involving speaker identity, gender, and vowels. The present study investigated whether such contrast effects can occur between voice and non-voice stimuli. A 10-step continuum between “voice” (/a/, /o/, or /u/ vowels) and “instrument” (bassoon, horn, or viola) was generated for each possible pair. In each trial, an adaptor, either voice or instrument, was played four times, followed by a test stimulus from along the appropriate continuum. When trials with voice and instrumental adaptors were grouped into separate blocks, strong contrastive adaptation effects were observed, with the test stimuli more likely to be identified as voice following instrumental adaptors and vice versa. Preliminary results comparing interleaved with blocked conditions and same-ear with different-ear conditions suggest longer-term build-up and persistence effects that may extend across both ears. [Work supported by NIH grant R01 DC012262.]

Inhibitory summation as a form of generalization.

Inhibitory learning after feature negative training (A+/AB-) is typically measured by combining the Feature B with a separately trained excitor (e.g., C) in a summation test. Reduced responding to C is taken as evidence that B has properties directly opposite to those of C. However, in human causal learning, transfer of B's inhibitory properties to another excitor is modest and depends on individual differences in inferred causal structure. Here we ask whether instead of opposing processes, a summation test might instead be thought of in terms of generalization. Using an allergist task, we tested whether inhibitory transfer would be influenced by similarity. We found that transfer was greater when the test stimuli were from the same semantic category as the training stimuli (Experiments 1 and 2) and when the test excitor had previously been associated with the same outcome (Experiment 3). We also found that the similarity effect applied across all self-reported causal structures. We conclude it may be more helpful to consider transfer of inhibition as a form of conceptual generalization rather than the arithmetic summation of opposing processes. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Effect of high-density additional rippled patterns on ripple density resolution thresholds

This study aims to spot an effect of the density of an additional rippled signal on ripple density resolution thresholds when this density is greatly exceeding the density of the main signal. In such a case a spectrum is formed from two harmonic functions. Therefore, a phase-reversed spectral ripple resolution test was used in this research, which includes two experimental paradigms. In both 2 oct narrowband white noise passes through pre-made filters. A ripple density of the additional signal was varied from 10 to 50 ripples/oct. In a rippled test and reference stimuli the mean resolution was 9 ripples/oct. This fact supports the involvement of cochlear excitation patterns for the discrimination of such signals. In a test with the stimuli with an additional rippled signal and non-rippled reference signal the thresholds cannot be reduced to mean value. However, the ripple density resolution thresholds for 20, 30, and 50 ripple densities of additional signal gravitate towards the value of 11,25 ripples/oct. The ripple density resolution thresholds for 10 and 15 ripples/oct are higher than the other values what suggests a special combination of spectral and temporal mechanisms.