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Journal of Vision May 2024Image differences between the eyes can cause interocular discrepancies in the speed of visual processing. Millisecond-scale differences in visual processing speed can...
Image differences between the eyes can cause interocular discrepancies in the speed of visual processing. Millisecond-scale differences in visual processing speed can cause dramatic misperceptions of the depth and three-dimensional direction of moving objects. Here, we develop a monocular and binocular continuous target-tracking psychophysics paradigm that can quantify such tiny differences in visual processing speed. Human observers continuously tracked a target undergoing Brownian motion with a range of luminance levels in each eye. Suitable analyses recover the time course of the visuomotor response in each condition, the dependence of visual processing speed on luminance level, and the temporal evolution of processing differences between the eyes. Importantly, using a direct within-observer comparison, we show that continuous target-tracking and traditional forced-choice psychophysical methods provide estimates of interocular delays that agree on average to within a fraction of a millisecond. Thus, visual processing delays are preserved in the movement dynamics of the hand. Finally, we show analytically, and partially confirm experimentally, that differences between the temporal impulse response functions in the two eyes predict how lateral target motion causes misperceptions of motion in depth and associated tracking responses. Because continuous target tracking can accurately recover millisecond-scale differences in visual processing speed and has multiple advantages over traditional psychophysics, it should facilitate the study of temporal processing in the future.
Topics: Humans; Motion Perception; Psychophysics; Vision, Binocular; Photic Stimulation; Adult; Depth Perception; Male; Vision, Monocular; Female; Young Adult; Reaction Time
PubMed: 38722274
DOI: 10.1167/jov.24.5.4 -
Journal of Vision May 2024A key question in perception research is how stimulus variations translate into perceptual magnitudes, that is, the perceptual encoding process. As experimenters, we...
A key question in perception research is how stimulus variations translate into perceptual magnitudes, that is, the perceptual encoding process. As experimenters, we cannot probe perceptual magnitudes directly, but infer the encoding process from responses obtained in a psychophysical experiment. The most prominent experimental technique to measure perceptual appearance is matching, where observers adjust a probe stimulus to match a target in its appearance along the dimension of interest. The resulting data quantify the perceived magnitude of the target in physical units of the probe, and are thus an indirect expression of the underlying encoding process. In this paper, we show analytically and in simulation that data from matching tasks do not sufficiently constrain perceptual encoding functions, because there exist an infinite number of pairs of encoding functions that generate the same matching data. We use simulation to demonstrate that maximum likelihood conjoint measurement (Ho, Landy, & Maloney, 2008; Knoblauch & Maloney, 2012) does an excellent job of recovering the shape of ground truth encoding functions from data that were generated with these very functions. Finally, we measure perceptual scales and matching data for White's effect (White, 1979) and show that the matching data can be predicted from the estimated encoding functions, down to individual differences.
Topics: Humans; Psychophysics; Visual Perception; Photic Stimulation
PubMed: 38722273
DOI: 10.1167/jov.24.5.5 -
Frontiers in Pain Research (Lausanne,... 2024This study investigates the impact of combining psychophysical stress, induced by forced swim (FSS), with masseter inflammation on reactive oxygen species (ROS)...
This study investigates the impact of combining psychophysical stress, induced by forced swim (FSS), with masseter inflammation on reactive oxygen species (ROS) production in trigeminal ganglia (TG), TRPA1 upregulation in TG, and mechanical hyperalgesia. In a rat model, we demonstrate that FSS potentiates and prolongs CFA-induced ROS upregulation within TG. The ROS levels in CFA combined with FSS group surpass those in the CFA-only group on days 4 and 28 post-treatment. FSS also enhances TRPA1 upregulation in TG, with prolonged expression compared to CFA alone. Furthermore, CFA-induced mechanical hyperalgesia is significantly prolonged by FSS, persisting up to day 28. PCR array analyses reveal distinct alterations in oxidative stress genes under CFA and CFA combined with FSS conditions, suggesting an intricate regulation of ROS within TG. Notably, genes like , , , and exhibit significant changes, providing potential targets for managing oxidative stress and inflammatory pain. Western blot and immunohistochemistry confirm DUOX1 protein upregulation and localization in TG neurons, indicating a role in ROS generation under inflammatory and stress conditions. This study underscores the complex interplay between psychophysical stress, inflammation, and oxidative stress in the trigeminal system, offering insights into novel therapeutic targets for pain management.
PubMed: 38721062
DOI: 10.3389/fpain.2024.1372942 -
Vision Research Aug 2024We used the psychophysical summation paradigm to reveal some spatial characteristics of the mechanism responsible for detecting a motion-defined visual target in central...
We used the psychophysical summation paradigm to reveal some spatial characteristics of the mechanism responsible for detecting a motion-defined visual target in central vision. There has been much previous work on spatial summation for motion detection and direction discrimination, but none has assessed it in terms of the velocity threshold or used velocity noise to provide a measure of the efficiency of the velocity processing mechanism. Motion-defined targets were centered within square fields of randomly selected gray levels. The motion was produced within the disk-shaped target region by shifting the pixels rightwards for 0.2 s. The uniform target motion was perturbed by Gaussian motion noise in horizontal strips of 16 pixels. Independent variables were field size, the diameter of the disk target, and the variance of an independent perturbation added to the (signed) velocity of each 16-pixel strip. The dependent variable was the threshold velocity for target detection. Velocity thresholds formed swoosh-shaped (descending, then ascending) functions of target diameter. Minimum values were obtained when targets subtended approximately 2 degrees of visual angle. The data were fit with a continuum of models, extending from the theoretically ideal observer through various inefficient and noisy refinements thereof. In particular, we introduce the concept of sparse sampling to account for the relative inefficiency of the velocity thresholds. The best fits were obtained from a model observer whose responses were determined by comparing the velocity profile of each stimulus with a limited set of sparsely sampled "DoG" templates, each of which is the product of a random binary array and the difference between two 2-D Gaussian density functions.
Topics: Humans; Motion Perception; Sensory Thresholds; Psychophysics; Photic Stimulation; Discrimination, Psychological; Space Perception; Adult
PubMed: 38718618
DOI: 10.1016/j.visres.2024.108422 -
Brain and Behavior May 2024In previous animal studies, sound enhancement reduced tinnitus perception in cases associated with hearing loss. The aim of this study was to investigate the efficacy of... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
In previous animal studies, sound enhancement reduced tinnitus perception in cases associated with hearing loss. The aim of this study was to investigate the efficacy of sound enrichment therapy in tinnitus treatment by developing a protocol that includes criteria for psychoacoustic characteristics of tinnitus to determine whether the etiology is related to hearing loss.
METHODS
A total of 96 patients with chronic tinnitus were included in the study. Fifty-two patients in the study group and 44 patients in the placebo group considered residual inhibition (RI) outcomes and tinnitus pitches. Both groups received sound enrichment treatment with different spectrum contents. The tinnitus handicap inventory (THI), visual analog scale (VAS), minimum masking level (MML), and tinnitus loudness level (TLL) results were compared before and at 1, 3, and 6 months after treatment.
RESULTS
There was a statistically significant difference between the groups in THI, VAS, MML, and TLL scores from the first month to all months after treatment (p < .01). For the study group, there was a statistically significant decrease in THI, VAS, MML, and TLL scores in the first month (p < .01). This decrease continued at a statistically significant level in the third month of posttreatment for THI (p < .05) and at all months for VAS-1 (tinnitus severity) (p < .05) and VAS-2 (tinnitus discomfort) (p < .05).
CONCLUSION
In clinical practice, after excluding other factors related to the tinnitus etiology, sound enrichment treatment can be effective in tinnitus cases where RI is positive and the tinnitus pitch is matched with a hearing loss between 45 and 55 dB HL in a relatively short period of 1 month.
Topics: Tinnitus; Humans; Male; Female; Middle Aged; Adult; Hearing Loss; Treatment Outcome; Aged; Acoustic Stimulation; Sound; Psychoacoustics
PubMed: 38715412
DOI: 10.1002/brb3.3520 -
MedRxiv : the Preprint Server For... Apr 2024Time-order error, a psychophysical phenomenon in which the duration in between successive stimuli alters perception, has been studied for decades by neuroscientists and...
Time-order error, a psychophysical phenomenon in which the duration in between successive stimuli alters perception, has been studied for decades by neuroscientists and psychologists. To date, however, the locus of these effects is unknown. We use intracortical microstimulation of somatosensory cortex in humans as a tool to bypass initial stages of processing and restrict the possible locations that signals could be modified. We find that, using both amplitude discrimination and magnitude estimation paradigms, intracortical microstimulation reliably evoked time-order errors across all participants. Points of subjective equality were symmetrically shifted during amplitude discrimination experiments and the intensity of a successive stimulus was perceived as being more intense when compared to single stimulus trials in magnitude estimation experiments. The error was reduced for both paradigms at longer inter-stimulus intervals. These results show that direct activation of primary somatosensory cortex is sufficient to induce time-order errors.
PubMed: 38712172
DOI: 10.1101/2024.04.19.24305901 -
BioRxiv : the Preprint Server For... Apr 2024Event-related potentials (ERPs) are a superposition of electric potential differences generated by neurophysiological activity associated with psychophysical events....
Event-related potentials (ERPs) are a superposition of electric potential differences generated by neurophysiological activity associated with psychophysical events. Spatiotemporal dissociation of these signal sources can supplement conventional ERP analysis and improve source localization. However, results from established source separation methods applied to ERPs can be challenging to interpret. Hence, we have developed a recurrent neural network (RNN) method for blind source separation. The RNN transforms input step pulse signals representing events into corresponding ERP difference waveforms. Source waveforms are obtained from penultimate layer units and scalp maps are obtained from feed-forward output layer weights that project these source waveforms onto EEG electrode amplitudes. An interpretable, sparse source representation is achieved by incorporating L1 regularization of signals obtained from the penultimate layer of the network during training. This RNN method was applied to four ERP difference waveforms (MMN, N170, N400, P3) from the open-access ERP CORE database, and independent component analysis (ICA) was applied to the same data for comparison. The RNN decomposed these ERPs into eleven spatially and temporally separate sources that were less noisy, tended to be more ERP-specific, and were less similar to each other than ICA-derived sources. The RNN sources also had less ambiguity between source waveform amplitude, scalp potential polarity, and equivalent current dipole orientation than ICA sources. In conclusion, the proposed RNN blind source separation method can be effectively applied to grand-average ERP difference waves and holds promise for further development as a computational model of event-related neural signals.
PubMed: 38712076
DOI: 10.1101/2024.04.23.590794 -
BMC Cardiovascular Disorders May 2024Spontaneous coronary artery dissection (SCAD) is an underdiagnosed cause of acute coronary syndrome, particularly in younger women. Due to limited information about...
BACKGROUND
Spontaneous coronary artery dissection (SCAD) is an underdiagnosed cause of acute coronary syndrome, particularly in younger women. Due to limited information about SCAD, case reports and case series can provide valuable insights into its features and management. This study aimed to comprehensively evaluate the features of SCAD patients who experienced psychophysical stress before the SCAD event.
METHODS
We conducted an electronic search of PubMed, Scopus, and Web of Science from inception until January 7, 2023. We included case reports or series that described patients with SCAD who had experienced psychophysical stress before SCAD. Patients with pregnancy-associated SCAD were excluded from our analysis.
RESULTS
In total, we included 93 case reports or series describing 105 patients with SCAD. The average patient age was 44.29 ± 13.05 years and a total of 44 (41.9%) of patients were male. Among the included SCAD patients the most prevalent comorbidities were fibromuscular dysplasia (FMD) and hypertension with the prevalence of 36.4 and 21.9%, respectively. Preceding physical stress was more frequently reported in men than in women; 38 out of 44 (86.4%) men reported physical stress, while 36 out of 61 (59.1%) females reported physical stress (p value = 0.009). On the other hand, the opposite was true for emotional stress (men: 6 (13.6%)), women: 29 (47.6%), p value < 0.001). Coronary angiography was the main diagnostic tool. The most frequently involved artery was the left anterior descending (LAD) (62.9%). In our study, recurrence of SCAD due to either the progression of a previous lesion or new SCAD in another coronary location occurred more frequently in those treated conservatively, however the observed difference was not statistically significant (p value = 0.138).
CONCLUSION
While physical stress seems to precede SCAD in most cases, emotional stress is implicated in females more than males.
Topics: Adult; Female; Humans; Male; Middle Aged; Case Reports as Topic; Comorbidity; Coronary Vessel Anomalies; Prevalence; Prognosis; Risk Assessment; Risk Factors; Sex Factors; Stress, Psychological; Vascular Diseases
PubMed: 38702627
DOI: 10.1186/s12872-024-03902-2 -
Communications Biology May 2024An organism's ability to accurately anticipate the sensations caused by its own actions is crucial for a wide range of behavioral, perceptual, and cognitive functions....
An organism's ability to accurately anticipate the sensations caused by its own actions is crucial for a wide range of behavioral, perceptual, and cognitive functions. Notably, the sensorimotor expectations produced when touching one's own body attenuate such sensations, making them feel weaker and less ticklish and rendering them easily distinguishable from potentially harmful touches of external origin. How the brain learns and keeps these action-related sensory expectations updated is unclear. Here we employ psychophysics and functional magnetic resonance imaging to pinpoint the behavioral and neural substrates of dynamic recalibration of expected temporal delays in self-touch. Our psychophysical results reveal that self-touches are less attenuated after systematic exposure to delayed self-generated touches, while responses in the contralateral somatosensory cortex that normally distinguish between delayed and nondelayed self-generated touches become indistinguishable. During the exposure, the ipsilateral anterior cerebellum shows increased activity, supporting its proposed role in recalibrating sensorimotor predictions. Moreover, responses in the cingulate areas gradually increase, suggesting that as delay adaptation progresses, the nondelayed self-touches trigger activity related to cognitive conflict. Together, our results show that sensorimotor predictions in the simplest act of touching one's own body are upheld by a sophisticated and flexible neural mechanism that maintains them accurate in time.
Topics: Humans; Somatosensory Cortex; Male; Magnetic Resonance Imaging; Cerebellum; Female; Adult; Young Adult; Touch Perception; Touch
PubMed: 38702520
DOI: 10.1038/s42003-024-06188-4 -
Behavior Research Methods Apr 2024Music is omnipresent among human cultures and moves us both physically and emotionally. The perception of emotions in music is influenced by both psychophysical and...
Music is omnipresent among human cultures and moves us both physically and emotionally. The perception of emotions in music is influenced by both psychophysical and cultural factors. Chinese traditional instrumental music differs significantly from Western music in cultural origin and music elements. However, previous studies on music emotion perception are based almost exclusively on Western music. Therefore, the construction of a dataset of Chinese traditional instrumental music is important for exploring the perception of music emotions in the context of Chinese culture. The present dataset included 273 10-second naturalistic music excerpts. We provided rating data for each excerpt on ten variables: familiarity, dimensional emotions (valence and arousal), and discrete emotions (anger, gentleness, happiness, peacefulness, sadness, solemnness, and transcendence). The excerpts were rated by a total of 168 participants on a seven-point Likert scale for the ten variables. Three labels for the excerpts were obtained: familiarity, discrete emotion, and cluster. Our dataset demonstrates good reliability, and we believe it could contribute to cross-cultural studies on emotional responses to music.
Topics: Humans; Music; Emotions; Female; Male; Adult; China; Young Adult; Auditory Perception; Reproducibility of Results; Recognition, Psychology; Arousal; East Asian People
PubMed: 38702502
DOI: 10.3758/s13428-024-02411-6