White Noise Bursts Research Articles

Distortion of overlapping memories relates to arousal and anxiety.

Everyday experiences often overlap, challenging our ability to maintain distinct episodic memories. One way to resolve such interference is by exaggerating subtle differences between remembered events, a phenomenon known as memory repulsion. Here, we tested whether repulsion is influenced by emotional arousal, when resolving memory interference is perhaps most needed. We adapted an existing paradigm in which participants repeatedly studied object-face associations. Participants studied two different-colored versions of each object: a to-be-tested "target" and its not-to-be-tested "competitor" pair mate. The level of interference between target and competitor pair mates was manipulated by making the object colors either highly similar or less similar, depending on the participant group. To manipulate arousal, the competitor object-face associations were preceded by either a neutral tone or an aversive and arousing burst of white noise. Memory distortion for the color of the target objects was tested after each study round to examine whether memory distortions emerge after learning. We found that participants with greater sound-induced pupil dilations, an index of physiological arousal, showed greater memory attraction of target colors towards highly similar competitor colors. Greater memory attraction was also correlated with greater memory interference in the last round of learning. Additionally, individuals who self-reported higher trait anxiety showed greater memory attraction when one of the overlapping memories was associated with something aversive. Our findings suggest that memories of similar neutral and arousing events may blur together after repeated exposures, especially in individuals who show higher arousal responses and symptoms of anxiety.

EVIDENCE FOR AUDITORY STIMULUS-SPECIFIC ADAPTATION BUT NOT DEVIANCE DETECTION IN LARVAL ZEBRAFISH BRAINS.

Animals receive a constant stream of sensory input, and detecting changes in this sensory landscape is critical to their survival. One signature of change detection in humans is the auditory mismatch negativity (MMN), a neural response to unexpected stimuli that deviate from a predictable sequence. This process requires the auditory system to adapt to specific repeated stimuli while remaining sensitive to novel input (stimulus-specific adaptation). MMN was originally described in humans, and equivalent responses have been found in other mammals and birds, but it is not known to what extent this deviance detection circuitry is evolutionarily conserved. Here we present the first evidence for stimulus-specific adaptation in the brain of a teleost fish, using whole-brain calcium imaging of larval zebrafish at single-neuron resolution with selective plane illumination microscopy. We found frequency-specific responses across the brain with variable response amplitudes for frequencies of the same volume, and created a loudness curve to model this effect. We presented an auditory 'oddball' stimulus in an otherwise predictable train of pure tone stimuli, and did not find a population of neurons with specific responses to deviant tones that were not otherwise explained by stimulus-specific adaptation. Further, we observed no deviance responses to an unexpected omission of a sound in a repetitive sequence of white noise bursts. These findings extend the known scope of auditory adaptation and deviance responses across the evolutionary tree, and lay groundwork for future studies to describe the circuitry underlying auditory adaptation at the level of individual neurons.

Auditory aversive generalization learning prompts threat-specific changes in alpha-band activity.

Pairing a neutral stimulus with aversive outcomes prompts neurophysiological and autonomic changes in response to the conditioned stimulus (CS+), compared to cues that signal safety (CS-). One of these changes-selective amplitude reduction of parietal alpha-band oscillations-has been reliably linked to processing of visual CS+. It is, however, unclear to what extent auditory conditioned cues prompt similar changes, how these changes evolve as learning progresses, and how alpha reduction in the auditory domain generalizes to similar stimuli. To address these questions, 55 participants listened to three sine wave tones, with either the highest or lowest pitch (CS+) being associated with a noxious white noise burst. A threat-specific (CS+) reduction in occipital-parietal alpha-band power was observed similar to changes expected for visual stimuli. No evidence for aversive generalization to the tone most similar to the CS+ was observed in terms of alpha-band power changes, aversiveness ratings, or pupil dilation. By-trial analyses found that selective alpha-band changes continued to increase as aversive conditioning continued, beyond when participants reported awareness of the contingencies. The results support a theoretical model in which selective alpha power represents a cross-modal index of continuous aversive learning, accompanied by sustained sensory discrimination of conditioned threat from safety cues.

Representing patient vital signs with overlapping or serial earcon components

There is interest in how clinicians can achieve good awareness of their patients’ wellbeing in a way that is not provided by conventional alarms. Earcons (short abstract sound motifs) provide an alternative. In three experiments we explored how effectively normal and abnormal levels of a patient's heart rate (HR), arterial oxygen saturation (SpO2) and blood pressure (BP) could be conveyed using two different earcon designs: overlapping (individual earcons for each vital sign played at the same time) or serial (individual earcons played one after the other). HR was mapped to the tremolo (sound vibration) rate in short bursts of white noise, SpO2 was mapped to the relative pitch of a tone, and BP was mapped to the range of an upward or downward sweep of pitch (chirp) of a tone. Experiment 1 compared how well non-clinician participants could identify HR and SpO2 using overlapping and serial mappings and found no difference in accuracy either for mapping or across vital signs. Experiment 2 added the BP vital sign, and compared overlapping and serial mappings. Identification accuracy was better with the serial mapping than with the overlapping mapping, and better for HR than for either SpO2 or BP. Experiment 3 replicated Experiment 2 but added conditions in which participants were cued to report a single vital sign in order to check whether memory limits or output interference were constraining the ability to report vital signs. When the cue appeared after the earcons were played, approximating a classic partial report paradigm, there was no improvement in identification accuracy, suggesting that earcon interpretability rather than memory load or output interference was constraining responses. However, when the cue appeared before the earcons were played, identification improved, suggesting that focused attention aided interpretation of the earcons. Although design modifications are needed, the results suggest that three vital signs may best be displayed in serial presentation for clinicians to maintain awareness of a patient's wellbeing in a convenient eyes-free manner.

Diminished autonomic nervous system responses to acoustic startle in progressive supranuclear palsy (S8.003)

<h3>Objective:</h3> To examine possible autonomic changes associated with progressive supranuclear palsy in response to a strong, unanticipated stimulus. <h3>Background:</h3> Progressive supranuclear palsy (PSP) is a neurodegenerative disorder that causes serious problems in eye movements, walking, and balance, and is also often associated with cognitive, emotional, and behavioral changes. In other movement disorders such as Parkinson’s disease, similar symptoms have often been associated with changes in autonomic nervous system (ANS) functioning. Despite this, previous studies have rarely examined ANS functioning in PSP.. In the present study, we determined whether ANS responses to an emotionally provocative stimulus were altered in PSP. We tested the hypothesis that ANS responses to an unanticipated aversive auditory stimulus (i.e., a brief, loud burst of white noise) designed to induce a startle response would differ between patients with PSP compared to healthy controls (HC). <h3>Design/Methods:</h3> Participants included 33 PSP patients and 38 HC. Participants sat still for a 60 second baseline and heard a brief (100-ms) loud (115-dB) burst of white noise without warning. Continuous measures of cardiac interbeat intervals (IBI; decreases in IBI correspond to increases in heart rate) and skin conductance levels (SCL) were obtained throughout the task. <h3>Results:</h3> Compared to HC, PSP patients showed significantly less decrease in IBI (i.e., less increase in heart rate) and less increase in SCL from baseline during the 10 seconds after stimulus onset. <h3>Conclusions:</h3> Less decrease in IBI and less increase in SCL in the face of a strong external stimulus suggests a diminished sympathetic nervous system response. In light of previous research suggesting that peripheral sympathetic responses are relatively preserved in the setting of orthostatic postural testing in PSP, we suspect this relates to a brainstem degeneration in a pontine circuit that is critical for startle reflexes during emotional challenges. <b>Disclosure:</b> The institution of Dr. Pressman has received research support from Premiere. Dr. Pressman has received personal compensation in the range of $100,000-$499,999 for serving as a Associate Professor with University of Colorado School of Medicine. The institution of Dr. Chen has received research support from National Institute on Aging. Ms. Bullard has nothing to disclose. The institution of Dr. Rankin has received research support from Marcus Foundation. Robert Levenson has nothing to disclose.

Sound order discrimination in two species of birds-Taeniopygia guttata and Melopsittacus undulatus.

Recent psychophysical experiments have shown that zebra finches (Taeniopygia guttata-a songbird) are surprisingly insensitive to syllable sequence changes in their species-specific motifs while budgerigars (Melopsittacus undulatus-a psittacine) do much better when tested on exactly the same sounds. This is unexpected since zebra finch males learn the order of syllables in their songs when young and sing the same song throughout adulthood. Here we probe the limits of this species difference by testing birds on an order change involving just two syllables, hereafter called bi-syllable phrases. Results show budgerigars still perform better than zebra finches on an order change involving just two syllables. An analysis of response latencies shows that both species respond to an order change in a bi-syllable motif at the onset of the first syllable rather than listening to the entire sequence before responding. Additional tests with one syllable omitted or doubled, or with white noise bursts substituted for syllables, indicate that the first syllable in the sequence has a dominant effect on subsequent discrimination of changes in a bi-syllable pattern. These results are surprising in that zebra finch males sing their full motif syllable sequence with a high degree of stereotypy throughout life, suggesting that this consistency in production may not rely on perceptual mechanisms for processing syllable order in adulthood. Budgerigars, on the other hand, are quite sensitive to bi-syllable order changes, an ability that may be related to useful information being encoded in the sequence of syllables in their natural song. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Increased pupil and heart-rate responses to sexual stimuli in men after physical exertion.

Physical stress has been found to enhance arousability by visual sexual stimuli on a short-term basis, as reflected in higher phasic pupil dilation responses, probably mediated by sympathetic nervous system (SNS)-related processes. However, previous research has not addressed the specificity of this effect in terms of emotional valence, that is, whether it reflects an instance of general excitation transfer or a more specific mechanism. Thus, to further investigate changes in sexual processing after acute stress exposure, 40 male participants underwent either a predominantly sympathetic stressor (3min sustained handgrip) or similar control procedure. After stress induction, pictures varying in valence as well as sexual versus non-sexual arousal were presented (for 5000 ms each). Using principal component analysis, pupillary responses during picture viewing were dissociated into fast and slow components (early vs. late response phases). In addition, startle eyeblink responses were elicited by bursts of white noise (50 ms, 105 dB) in half of the trials and recorded at the orbicularis oculi via electromyography. Skin conductance and heart rate were co-registered, as well. While affective startle modulation and skin conductance responses to emotional stimuli were unaffected by previous stress exposure, both evoked heart-rate deceleration (but not acceleration) and pupil responses were specifically enhanced with sexually arousing stimuli in stressed participants, and this effect was mediated by blood pressure reactivity as an index of preceding SNS activation. Taken together, our findings provide strong evidence for enhancement of sexual processing by acute stress exposure in men and suggest differential involvement of parasympathetic versus sympathetic mechanisms.

Attentional load effects on emotional content in face working memory.

This study investigated the role of attentional resources in processing emotional faces in working memory (WM). Participants memorised two face arrays with the same emotion but different identities and were required to judge whether the test face had the same identity as one of the previous faces. Concurrently during encoding and maintenance, a sequence of high- or low-pitched tones (high load) or white noise bursts (low load) was presented, and participants were required to count how many low-tones were heard. Experiments 1 and 2 used an emotional and neutral test face, respectively. The results revealed a significant WM impairment for sad and angry faces in the high-load versus low-load condition but not for happy faces. In Experiment 1, participants remembered happy faces better than other emotional faces. In contrast, Experiment 2 showed that performance was poorer for happy than sad faces but not for angry faces. This evidence suggests that depleting attentional resources has less impact on WM for happy faces than other emotional faces, but also that differential effects on WM for emotional faces depend on the presence or absence of emotion in the probe face at retrieval.

Auditory timing-tuned neural responses in the human auditory cortices

Perception of sub-second auditory event timing supports multisensory integration, and speech and music perception and production. Neural populations tuned for the timing (duration and rate) of visual events were recently described in several human extrastriate visual areas. Here we ask whether the brain also contains neural populations tuned for auditory event timing, and whether these are shared with visual timing. Using 7T fMRI, we measured responses to white noise bursts of changing duration and rate. We analyzed these responses using neural response models describing different parametric relationships between event timing and neural response amplitude. This revealed auditory timing-tuned responses in the primary auditory cortex, and auditory association areas of the belt, parabelt and premotor cortex. While these areas also showed tonotopic tuning for auditory pitch, pitch and timing preferences were not consistently correlated. Auditory timing-tuned response functions differed between these areas, though without clear hierarchical integration of responses. The similarity of auditory and visual timing tuned responses, together with the lack of overlap between the areas showing these responses for each modality, suggests modality-specific responses to event timing are computed similarly but from different sensory inputs, and then transformed differently to suit the needs of each modality.

Leafcutter ants adjust foraging behaviours when exposed to noise disturbance.

We investigate the impact of anthropogenic noise on the foraging efficiency of leafcutter ants (Acromyrmex octospinosus) in a controlled laboratory experiment. Anthropogenic noise is a widespread, pervasive and increasing environmental pollutant and its negative impacts on animal fitness and behaviour have been well documented. Much of this evidence has come from studies concerning vertebrate species with very little evidence for terrestrial invertebrates, especially social living invertebrates. We compare movement speed, forage fragment size, and colony activity levels of ants exposed to intermittent elevated noise and in ambient noise conditions. We use intermittent and temporally unpredictable bursts of white noise produced from a vibration speaker to create the elevated noise profile. Ant movement speed increased under elevated noise conditions when travelling to collect forage material and when returning to the colony nest. The size of individually measured foraged material was significantly reduced under elevated noise conditions. Colony activity, the number of ants moving along the forage route, was not affected by elevated noise and was consistent throughout the foraging events. Increased foraging speed and smaller forage fragments suggests that the ants had to make more foraging trips over an extended period, which is likely to affect energy expenditure and increases exposure to predators. This is likely to have significant fitness impacts for the colony over time.

Impact of Startling Acoustic Stimuli on Word Repetition in Individuals With Aphasia and Apraxia of Speech Following Stroke.

The StartReact effect, whereby movements are elicited by loud, startling acoustic stimuli (SAS), allows the evaluation of movements when initiated through involuntary circuitry, before auditory feedback. When StartReact is applied during poststroke upper extremity movements, individuals exhibit increased muscle recruitment, reaction times, and reaching distances. StartReact releases unimpaired speech with similar increases in muscle recruitment and reaction time. However, as poststroke communication disorders have divergent neural circuitry from upper extremity tasks, it is unclear if StartReact will enhance speech poststroke. Our objective is to determine if (a) StartReact is present in individuals with poststroke aphasia and apraxia and (b) SAS exposure enhances speech intelligibility. We remotely delivered startling, 105-dB white noise bursts (SAS) and quiet, non-SAS cues to 15 individuals with poststroke aphasia and apraxia during repetition of six words. We evaluated average word intensity, pitch, pitch trajectories, vowel formants F1 and F2 (first and second formants), phonemic error rate, and percent incidence of each SAS versus non-SAS-elicited phoneme produced under each cue type. For SAS trials compared to non-SAS, speech intensity increased (∆ + 0.6 dB), speech pitch increased (∆ + 22.7 Hz), and formants (F1 and F2) changed, resulting in a smaller vowel space after SAS. SAS affected pitch trajectories for some, but not all, words. Non-SAS trials had more stops (∆ + 4.7 utterances) while SAS trials had more sustained phonemes (fricatives, glides, affricates, liquids; ∆ + 5.4 utterances). SAS trials had fewer distortion errors but no change in substitution errors or overall error rate compared to non-SAS trials. We show that stroke-impaired speech is susceptible to StartReact, evidenced by decreased intelligibility due to altered formants, pitch trajectories, and articulation, including increased incidence of sounds that could not be produced without SAS. Future studies should examine the impact of SAS on voluntary speech intelligibility and clinical measures of aphasia and apraxia.

Gender differences in aggression: A multiplicative function of outward anger expression.

Individuals with a higher (vs. lower) tendency to outwardly express anger (i.e., greater anger-out) generally exhibit greater aggression; men (vs. women) also tend to be more aggressive. Although the general aggression model posits that multiple person variables trigger aggression, the combined effects of multiple person variables are poorly understood. Thus, the aim of this study was to examine the nature of the relation between gender, anger-out, and reactive aggression. In particular, we were interested in whether the effects of anger-out and gender are additive or multiplicative. Specifically, we tested whether men exhibit higher levels of aggression than women at a consistent ratio across all levels of anger-out (i.e., the multiplicative model) or at a fixed amount depending on the level of anger-out (i.e., the additive interaction model). To this end, undergraduate participants (N = 203) completed a task in which they were falsely instructed that their objective was to respond more quickly than a same-sex opponent. They were told that whoever responded more quickly would administer a white noise burst to the opponent and choose its intensity, which served as our measure of aggression. Compared to an additive interaction model, the multiplicative model exhibited a better fit. Specifically, men displayed proportionately more aggression than women with the same level of anger-out. Research on and treatment for aggression should consider the multiplicative effects of factors related to aggression.

Early Auditory Event Related Potentials Distinguish Higher-Order From First-Order Aversive Conditioning.

Stimuli in reality rarely co-occur with primary reward or punishment to allow direct associative learning of value. Instead, value is thought to be inferred through complex higher-order associations. Rodent research has demonstrated that the formation and maintenance of first-order and higher-order associations are supported by distinct neural substrates. In this study, we explored whether this pattern of findings held true for humans. Participants underwent first-order and subsequent higher-order conditioning using an aversive burst of white noise or neutral tone as the unconditioned stimuli. Four distinct tones, initially neutral, served as first-order and higher-order conditioned stimuli. Autonomic and neural responses were indexed by pupillometry and evoked response potentials (ERPs) respectively. Conditioned aversive values of first-order and higher-order stimuli led to increased autonomic responses, as indexed by pupil dilation. Distinct temporo-spatial auditory evoked response potentials were elicited by first-order and high-order conditioned stimuli. Conditioned first-order responses peaked around 260 ms and source estimation suggested a primary medial prefrontal and amygdala source. Conversely, conditioned higher-order responses peaked around 120 ms with an estimated source in the medial temporal lobe. Interestingly, pupillometry responses to first-order conditioned stimuli were diminished after higher order training, possibly signifying concomitant incidental extinction, while responses to higher-order stimuli remained. This suggests that once formed, higher order associations are at least partially independent of first order conditioned representations. This experiment demonstrates that first-order and higher-order conditioned associations have distinct neural signatures, and like rodents, the medial temporal lobe may be specifically involved with higher-order conditioning.

Cardiac Startle Response and Clinical Outcomes in Preschool Children With Fragile X Syndrome and Autism Spectrum Disorder.

Objective: Poor physiological regulation in response to threat is linked to multiple negative developmental outcomes including anxiety, which is highly prevalent and impairing in young children with neurodevelopmental disabilities like fragile X syndrome (FXS) and autism spectrum disorder (ASD). The present study contrasted cardiac startle response in pre-school-aged children with FXS, with and without ASD, to children with non-syndromic ASD (nsASD) and neurotypical controls (NT). The relationship of cardiac startle to non-verbal mental age (NVMA), ASD severity, and parent-reported anxiety was also examined.Method: Four age-matched groups of pre-school children participated including those with FXS without ASD (FXS-Only, n = 21), FXS with ASD (FXS+ASD, n = 17), nsASD (n = 42), and NT children (n = 27). Participants viewed a silent movie during which a single 200 ms 98-decibel white noise burst occurred. Cardiac activity was analyzed for pre-stimulus respiratory sinus arrhythmia (RSA) and the inter-beat intervals (IBI) at the auditory stimulus and 10 s post-stimulus. The Spence Pre-school Anxiety Scale, Autism Diagnostic Observation Schedule-2nd Edition, and Mullen Scales of Early Learning were examined in relation to startle response.Results: The nsASD group demonstrated heightened cardiac activity at the auditory stimulus and 10 s post-stimulus compared to the NT controls. Neither of the FXS groups showed differences from any other group. Higher pre-stimulus RSA was associated with reduced cardiac response across groups, while the relationship between cognitive ability and ASD severity to cardiac response varied between groups. Parent-reported anxiety was not associated with cardiac response for any group.Conclusion: These findings demonstrate group distinctions in cardiac responses to auditory startle. Although FXS and ASD share behavioral characteristics, the nsASD group showed a heightened cardiac startle response compared to the NT group that was not present in the FXS groups with or without ASD. Non-verbal mental age was associated with greater stimulus or post-stimulus reactivity for all groups except the FXS+ASD group, which showed no association between startle response and any clinical outcomes. Increased understanding of the relationship between physiological regulation and clinical outcomes will assist in identifying the timing and targets for effective interventions for individuals with neurodevelopmental disabilities.

Political Orientation as Psychological Defense or Basic Disposition? A Social Neuroscience Examination

Psychological views on political orientation generally agree that conservatism is associated with negativity bias but disagree on the form of that association. Some view conservatism as a psychological defense that insulates from negative stimuli and events. Others view conservatism as a consequence of increased dispositional sensitivity to negative stimuli and events. Further complicating matters, research shows that conservatives are sometimes more and sometimes less sensitive to negative stimuli and events. The current research integrates these opposing views and results. We reasoned that conservatives should typically be less sensitive to negative stimuli if conservative beliefs act as a psychological defense. However, when core components of conservative beliefs are threatened, the psychological defense may fall, and conservatives may show heightened sensitivity to negative stimuli. In two ERP studies, participants were randomly assigned to either an ostensibly real economic threat or a nonthreatening control condition. To measure reactivity to negative stimuli, we indexed the P3 component to aversive white noise bursts in an auditory oddball paradigm. In both studies, the relationship between increased conservatism and P3 mean amplitude was negative in the control condition but positive in threat condition (this relationship was stronger in Study 2). In Study 2, source localization of the P3 component revealed that, after threat, conservatism was associated with increased activity in the anterior cingulate cortex and dorsomedial prefrontal cortex, regions associated with conflict-related processes. These results demonstrate that the link between conservatism and negativity bias is context-dependent, i.e., dependent on threat experiences.

Decoding expectation and surprise in dementia: the paradigm of music.

Making predictions about the world and responding appropriately to unexpected events are essential functions of the healthy brain. In neurodegenerative disorders, such as frontotemporal dementia and Alzheimer’s disease, impaired processing of ‘surprise’ may underpin a diverse array of symptoms, particularly abnormalities of social and emotional behaviour, but is challenging to characterize. Here, we addressed this issue using a novel paradigm: music. We studied 62 patients (24 female; aged 53–88) representing major syndromes of frontotemporal dementia (behavioural variant, semantic variant primary progressive aphasia, non-fluent-agrammatic variant primary progressive aphasia) and typical amnestic Alzheimer’s disease, in relation to 33 healthy controls (18 female; aged 54–78). Participants heard famous melodies containing no deviants or one of three types of deviant note—acoustic (white-noise burst), syntactic (key-violating pitch change) or semantic (key-preserving pitch change). Using a regression model that took elementary perceptual, executive and musical competence into account, we assessed accuracy detecting melodic deviants and simultaneously recorded pupillary responses and related these to deviant surprise value (information-content) and carrier melody predictability (entropy), calculated using an unsupervised machine learning model of music. Neuroanatomical associations of deviant detection accuracy and coupling of detection to deviant surprise value were assessed using voxel-based morphometry of patients’ brain MRI. Whereas Alzheimer’s disease was associated with normal deviant detection accuracy, behavioural and semantic variant frontotemporal dementia syndromes were associated with strikingly similar profiles of impaired syntactic and semantic deviant detection accuracy and impaired behavioural and autonomic sensitivity to deviant information-content (all P < 0.05). On the other hand, non-fluent-agrammatic primary progressive aphasia was associated with generalized impairment of deviant discriminability (P < 0.05) due to excessive false-alarms, despite retained behavioural and autonomic sensitivity to deviant information-content and melody predictability. Across the patient cohort, grey matter correlates of acoustic deviant detection accuracy were identified in precuneus, mid and mesial temporal regions; correlates of syntactic deviant detection accuracy and information-content processing, in inferior frontal and anterior temporal cortices, putamen and nucleus accumbens; and a common correlate of musical salience coding in supplementary motor area (all P < 0.05, corrected for multiple comparisons in pre-specified regions of interest). Our findings suggest that major dementias have distinct profiles of sensory ‘surprise’ processing, as instantiated in music. Music may be a useful and informative paradigm for probing the predictive decoding of complex sensory environments in neurodegenerative proteinopathies, with implications for understanding and measuring the core pathophysiology of these diseases.

Generalised gravitational wave burst generation with generative adversarial networks

We introduce the use of conditional generative adversarial networks (CGANs) for generalised gravitational wave (GW) burst generation in the time domain. Generative adversarial networks are generative machine learning models that produce new data based on the features of the training data set. We condition the network on five classes of time-series signals that are often used to characterise GW burst searches: sine-Gaussian, ringdown, white noise burst, Gaussian pulse and binary black hole merger. We show that the model can replicate the features of these standard signal classes and, in addition, produce generalised burst signals through interpolation and class mixing. We also present an example application where a convolutional neural network (CNN) classifier is trained on burst signals generated by our CGAN. We show that a CNN classifier trained only on the standard five signal classes has a poorer detection efficiency than a CNN classifier trained on a population of generalised burst signals drawn from the combined signal class space.

Contactless differentiation of pleasant and unpleasant valence: Assessment of the acoustic startle eyeblink response with infrared reflectance oculography.

The ability to distinguish between discrete emotions by monitoring autonomic or facial features has been an elusive "holy grail" for fields such as psychophysiology, affective computing, and human-computer interface design. However, cross-validated models are lacking, and contemporary theory suggests that emotions may lack distinct physiological or facial "signatures." Therefore, in this study, we propose a reorientation toward distinguishing between pleasant and unpleasant affective valence. We focus on the acoustic eyeblink response, which exhibits affective modulation but remains underutilized. The movement of the eyelid was monitored in a contactless manner via infrared reflectance oculography at 1 kHz while 36 participants viewed normatively pleasant, neutral, and unpleasant images, and 50-ms bursts of white noise were presented binaurally via headphones. Startle responses while viewing pleasant images exhibited significantly smaller amplitudes than those while viewing unpleasant images, with a large effect size (d = 1.56). The affective modulation of the eyeblink startle response is a robust phenomenon that can be assessed in a contactless manner. As research continues on whether systems based on psychophysiological or facial features can distinguish between discrete emotions, the eyeblink startle response offers a relatively simple way to distinguish between pleasant and unpleasant affective valence.

High-frequency sound components of high-resolution audio are not detected in auditory sensory memory

High-resolution digital audio is believed to produce a better listening experience than the standard quality audio, such as compact disks (CDs) and digital versatile disks (DVDs). One common belief is that high-resolution digital audio is superior due to the higher frequency (> 22 kHz) of its sound components, a characteristic unique to this audio. This study examined whether sounds with high-frequency components were processed differently from similar sounds without these components in the auditory cortex. Mismatch negativity (MMN), an electrocortical index of auditory deviance detection in sensory memory, was recorded in young adults with normal hearing (N = 38) using two types of white noise bursts: original sound and digitally filtered sound from which high-frequency components were removed. The two sounds did not produce any MMN response and could not be discriminated behaviourally. In conclusion, even if high-resolution audio is superior to the standard format, the difference is apparently not detectable at the cortical level.

Economic threat heightens conflict detection: sLORETA evidence.

Economic threat has far-reaching emotional and social consequences, yet the impact of economic threat on neurocognitive processes has received little empirical scrutiny. Here, we examined the causal relationship between economic threat and conflict detection, a critical process in cognitive control associated with the anterior cingulate cortex (ACC). Participants (N = 103) were first randomly assigned to read about a gloomy economic forecast (Economic Threat condition) or a stable economic forecast (No-Threat Control condition). Notably, these forecasts were based on real, publicly available economic predictions. Participants then completed a passive auditory oddball task composed of frequent standard tones and infrequent, aversive white-noise bursts, a task that elicits the N2, an event-related potential component linked to conflict detection. Results revealed that participants in the Economic Threat condition evidenced increased activation source localized to the ACC during the N2 to white-noise stimuli. Further, ACC activation to conflict mediated an effect of Economic Threat on increased justification for personal wealth. Economic threat thus has implications for basic neurocognitive function. Discussion centers on how effects on conflict detection could shed light on the broader emotional and social consequences of economic threat.