Auditory forward and backward masking interaction

The joint effect of forward and backward visual masking appears to be more extended in time than that predicted from an algebraic summation of individual forward and backward masking effects. It is suggested that this apparent extension of the temporal range of masking arises from the summation of forward and backward masking effects which in themselves are insufficient to influence observed performance. Such latent masking effects are possible if it is not assumed that when stimulus identification reaches the 100% level the mask has no effect at all on the stimulus.

The differences in the suppression effect observed in forward and backward masking are consistent with an interpretation that suppression in forward masking results from a reduction of the effective level of the masker in the aditory periphery, and that the suppression in backward masking is influenced by these peripheral processes, but is dominated by additional, central processes. This conclusion is supported by experiments that show differences in the effect of ipsilateral versus contralateral presentation of the suppressor, and differences in the amount of the suppression observed as a function of the level, duration, and frequency of the suppressor.

Exploring facial emotion perception in schizophrenia using transcranial magnetic stimulation and spatial filtering

Deficient rapid auditory processing (RAP) has been associated with early language impairment and dyslexia. Using an auditory masking paradigm, children with language disabilities perform selectively worse than controls at detecting a tone in a backward masking (BM) condition (tone followed by white noise) compared to a forward masking (FM) condition (tone preceded by white noise). Tallal's (1980) auditory processing hypothesis posits that abnormal RAP leads to reduced (or impaired) phonological awareness (PA), resulting in reading and language difficulties. Alternative theories suggest that impaired PA may have more of a top-down effect on auditory processing. The current study examines RAP in children tested at two time points, average age 5.6 and average age 8.3, in order to test causal relations between RAP and PA in a path analysis. Additional hierarchical regressions examine how well RAP predicts reading ability when accounting for PA and vocabulary. The path analysis indicates a top-down effect, such that PA has a larger impact on BM over time than the reverse. Regressions indicate no direct impact of RAP on reading ability. The path analysis provides evidence against the auditory processing hypothesis and instead suggests that between the ages of 5 and 8 it is variability in early phonological representations that predicts subsequent lower-level rapid auditory processing.

The frequency selectivity of the peripheral ear (e.g., at the VIIIth nerve level) is so acute that onset and offset transients in responses to short signals produce a nonnegligible extension of the signal duration. Thus, peripheral excitation patterns produced by signals which were separated in time can overlap and thereby mask each other. We refer to this type of masking as transient masking. Published data on nonsimultaneous masking and the results of two new experiments are compared with the masking that may be expected from filter transients. It is concluded that backward masking is mainly due to interactions at the level of the filter outputs, and that in forward masking, in addition to a short-term component, a long-term component is distinguishable. The latter has an exponential decay with a time constant of approximately 75 msec, and is probably related to physiological adaptation effects.

A low-pass noise (1500-Hz cutoff) with a sinusoidal variation in its amplitude spectrum (ripple noise) was used to mask a 1000-Hz signal (10 msec) in both a forward and a simultaneous masking procedure. The masked thresholds of the signal were measured as a function of the number of peaks (ripples) in the amplitude spectrum of the noise. The procedure was similar to that used by Houtgast who reported it at the 83rd meeting of the Acoustical Society. Houtgast used a pulsation threshold technique with ripple noise to study frequency selectivity. Pulsation threshold is similar to simultaneous forward and backward masking. The data of the present study indicate that results similar, but not identical, to Houtgast's can be obtained with forward masking alone. The frequency selectivity obtained with the forward masking procedure is sharper than has been previously obtained and might indicate the presence of lateral inhibition.

Forward masking occurs when noise is presented before the target signal, making the latter difficult to be perceived. It is related to temporal auditory processing and consequently to speech recognition in noisy environments, which may decline with age. Interest in forward masking has grown in the last years. Studies investigate psychoacoustic and electrophysiological recordings in different age- groups. The purpose of the study was to investigate the effect of forward masking on frequency following response (FFR) as a function of age. Cross-sectional analytical observational study. We assessed 69 normal-hearing participants of both genders assigned to three groups: 40 young individuals (aged 18-25 years, mean age = 22 years 8 months), 21 middle-age individuals (aged 25-55 years, mean age = 37 years 2 months), and 8 seniors (aged <55 years, mean age = 65 years 3 months). FFRs were recorded using the /da/ syllable with and without noise. The /da/ syllable and speech-shaped noise were monaurally presented to the participants' right ears through ER-3a insert earphones. Electrodes were placed in M1 and M2 (-), Fz (+), and Fpz (ground). Acquisition occurred under two conditions: (1) the/da/ syllable presented without the noise and (2) the /da/ syllable presented 4 msec after the noise. Data show that (1) considering the mean values of all participants, there was a significant latency delay of all waves (PV, A, PW, PX, PY, PZ, and O) when the /da/ syllable was presented 4 msec after the masking noise as compared with the condition without noise, that is, forward masking occurred in all components of the FFR responses, and (2) for the youngest group and the middle-age group, forward masking was seen for all waves, except PX in the latter one; for the senior group, an irregular pattern was observed (presence of forward masking in PA, PY, PZ, and O). This pattern may be due to an aging effect on FFR responses even without noise presence, which makes it more difficult to identify forward masking effect in this population. Although it is well documented in the literature that forward masking increases with age, this is less evident on FFR recordings in the senior population. An aging effect was identified in FFR responses. Forward masking was identified in FFR responses of all groups but less evident in senior population.

This experiment demonstrated a relationship between prepulse inhibition (PPI) of the startle eyeblink and visual backward masking in college students. It was hypothesized that recovery from backward masking effects is due in part to sensory gating, as assessed by auditory and visual PPI. Visual presentations of letters served as targets or visual prepulses in an intermixed session of backward masking and PPI. Backward masking and PPI (both auditory and visual) were assessed at stimulus onset asynchronies of 30, 45, 60, 120, and 150 ms. A repeated-measures regression revealed that there was a relationship between backward masking and PPI for both visual and auditory PPI, with higher levels of PPI being associated with greater recovery from backward masking. The data are consistent with the hypothesis that recovery from backward masking effects is affected by sensory gating acting in part to gate out the interruptive effects of the mask.

There is strong evidence that emotions influence the learning process. For this reason, we explore the relevance of individual and general mouse and keyboard interaction patterns in real-world settings while learners perform free text tasks. To this end, we have modeled users’ mouse movements and keystroke dynamics with data mining techniques, building on previous related research and extending it in terms of some critical modeling issues that may have an impact on detection results. Inspired by practice in affective computing where physiological sensors are used, we argue for the creation of an interaction baseline model, as a reference point in the way how learners interact with the keyboard and mouse. To make the proposed affective model feasible, we have adopted a simplified 2-D self-labeling approach for labeling the users’ affective state. Our approach to affect detection improves results when there is a small amount of data instances available and does not require additional affect-oriented tasks from the learners. Specifically, learners are only asked to self-reflect their emotional state after finishing the tasks and immediately selecting two values in the affect scale. The approach we have followed aims to distill two types of interaction patterns: 1) within-subject patterns (from a single participant) and 2) between-subject patterns (across all participants). Doing this, we aim to combine both the approaches as modeling factors, thus taking advantage of individual and general interaction patterns to predict affect.

Background: Forward masking occurs when noise is presented before the target signal, making thelatter difficult to be perceived. It is related to temporal auditory processing and consequently to speechrecognition in noisy environments, which may decline with age. Interest in forward masking has grown inthe last years. Studies investigate psychoacoustic and electrophysiological recordings in different age groups.&lt;br /&gt;Purpose: The purpose of the study was to investigate the effect of forward masking on frequency followingresponse (FFR) as a function of age.&lt;br /&gt;Research Design: Cross-sectional analytical observational study.&lt;br /&gt;Study Sample: We assessed 69 normal-hearing participants of both genders assigned to three groups: 40young individuals (aged 18–25 years,mean age = 22 years, 8 months), 21 middle-age individuals (aged 25–55years, mean age = 37 years, 2 months), and 8 seniors (aged &lt; 55 years, mean age = 65 years, 3 months).&lt;br /&gt;Intervention: FFRs were recorded using the /da/ syllable with and without noise.&lt;br /&gt;Data Collection and Analysis: The /da/ syllable and speech-shaped noise were monaurally presentedto the participants’ right ears through ER-3a insert earphones. Electrodes were placed in M1 and M2 (-),Fz (+), and Fpz (ground). Acquisition occurred under two conditions: (1) the /da/ syllable presented withoutthe noise and (2) the /da/ syllable presented 4 msec after the noise.&lt;br /&gt;Results: Data show that (1) considering the mean values of all participants, there was a significant latencydelay of all waves (PV, A, PW, PX, PY, PZ, and O) when the /da/ syllable was presented 4 msecafter the masking noise as compared with the condition without noise, that is, forward masking occurredin all components of the FFR responses, and (2) for the youngest group and the middle-age group, forwardmasking was seen for all waves, except PX in the latter one; for the senior group, an irregular patternwas observed (presence of forward masking in PA, PY, PZ, and O). This pattern may be due to an agingeffect on FFR responses even without noise presence, which makes it more difficult to identify forwardmasking effect in this population. Although it is well documented in the literature that forward maskingincreases with age, this is less evident on FFR recordings in the senior population.&lt;br /&gt;Conclusions: An aging effect was identified in FFR responses. Forward masking was identified in FFRresponses of all groups but less evident in senior population.&lt;br /&gt;

Temporal masking of auditory evoked brainstem responses in human newborns and adults.

Monaural-intelligibility functions for monosyllabic words were obtained for seven subjects with normal hearing under the following major experimental conditions: (1) speech interrupted by silence at the rates of 1, 10, and 100 interruptions per second (ips); (2) speech alternating with noise (80 dB SPL) at rates of 1, 10, and 100 ips; (3) speech in interrupted noise (80 dB SPL) at rates of 1, 10, and 100 ips. The comparison between the intelligibility functions for Conditions 1 and 2 yielded a measure of the effects of forward and backward masking during the noise-free interval. The comparison between the intelligibility functions for Conditions 2 and 3 yielded a measure of the extent to which the speech signal during the noise burst contributed to intelligibility. The results indicated that the effect of forward and backward masking on intelligibility was substantial at 10 ips and even more pronounced at 100 ips. However, at 1 ips little masking effect was observed except at very adverse signal-to-noise (S/N) ratios. The findings also demonstrated that the speech heard within the noise burst contributed to intelligibility at favorable S/N ratios when the noise was interrupted one time per second. At 100 ips, the speech signal within the noise burst made only a small contribution to the total intelligibility score, and at 10 ips the function was formed almost entirely by the speech heard during the noise-free intervals.

The study focuses on reducing social ostracism and strengthening students’ sense of belonging in the university setting by implementing a comprehensive, theoretically grounded programme that combines early identification of risk, mentoring support, and structured collective activities. Methodology and Methods. A mixed-method, quasi-experimental before–and–after design without randomization was carried out with 161 undergraduate students and 34 faculty members; standardized assessment of ignoring, exclusion, and rejection via the OES-A scale was supplemented by a structured questionnaire, correlation and regression analyses, as well as brief focused group discussions to interpret and refine the quantitative findings. Results. The data showed that participation in the SOCI-Progress programme was associated with a statistically and practically significant reduction in all three components of ostracism (ignoring, exclusion, rejection), a weakening of the interscale correlations that previously reflected a tightly linked pattern of exclusion, and a marked increase in student involvement in mentoring, clubs, and initiative-based activities, particularly among first-year students. Scientific novelty. The study empirically substantiates the effectiveness of a multi-level, practice-oriented model in which educational modules, mentoring, and social integration initiatives together lower not only mean levels of ostracism but also the strength of connections between its components, thereby changing both individual experiences and typical patterns of interaction within the institution. Practical significance. The SOCI-Progress model can be used to improve the quality of the educational environment, to organize differentiated support for vulnerable groups (especially first-year and minority-status students), and to maintain higher motivation for participation in academic, social, and research activities through the systematic development of mentoring, open student groups, and combined offline/online support formats.

By lowering the risk of neurocognitive and chronic illnesses and facilitating informed decisions prior to traditional clinical diagnosis, this technology sets a new benchmark in preventive healthcare. One of the biggest obstacles to preventive healthcare is the early identification of pre-disease behaviours. Conventional diagnostic techniques frequently rely on overt symptoms, which manifest later in the illness. In this paper, a unique predictive AI framework is presented that analyses common interaction patterns in both digital and physical domains to detect modest pre-disease behavioural signals. Lifestyle/contextual data, typing and smartphone usage patterns, sleep metrics, physical activity, and voice prosody are just a few of the multi-modal data streams that the system integrates.By using attention-based deep neural networks with multi-scale feature fusion to minimize overfitting and dynamically prioritize informative signals, the model enables real-time monitoring of pre-disease states. Unlike previous disease-specific approaches, this framework identifies micro-deviations across multiple conditions, providing actionable insights for early intervention. Experimental validation on both synthetic and real-world datasets shows up to 99% predictive accuracy, outperforming single-modality models. An explainable AI layer enables clinicians to interpret feature contributions and personalize preventive measures.

It has been proposed that tinnitus is generated by aberrant neural activity that develops among neurons in tonotopic of regions of primary auditory cortex (A1) affected by hearing loss, which is also the frequency region where tinnitus percepts localize (Eggermont and Roberts 2004; Roberts et al., 2010, 2013). These models suggest (1) that differences between tinnitus and control groups of similar age and audiometric function should depend on whether A1 is probed in tinnitus frequency region (TFR) or below it, and (2) that brain responses evoked from A1 should track changes in the tinnitus percept when residual inhibition (RI) is induced by forward masking. We tested these predictions by measuring (128-channel EEG) the sound-evoked 40-Hz auditory steady-state response (ASSR) known to localize tonotopically to neural sources in A1. For comparison the N1 transient response localizing to distributed neural sources in nonprimary cortex (A2) was also studied. When tested under baseline conditions where tinnitus subjects would have heard their tinnitus, ASSR responses were larger in a tinnitus group than in controls when evoked by 500 Hz probes while the reverse was true for tinnitus and control groups tested with 5 kHz probes, confirming frequency-dependent group differences in this measure. On subsequent trials where RI was induced by masking (narrow band noise centered at 5 kHz), ASSR amplitude increased in the tinnitus group probed at 5 kHz but not in the tinnitus group probed at 500 Hz. When collapsed into a single sample tinnitus subjects reporting comparatively greater RI depth and duration showed comparatively larger ASSR increases after masking regardless of probe frequency. Effects of masking on ASSR amplitude in the control groups were completely reversed from those in the tinnitus groups, with no change seen to 5 kHz probes but ASSR increases to 500 Hz probes even though the masking sound contained no energy at 500 Hz (an “off-frequency” masking effect). In contrast to these findings for the ASSR, N1 amplitude was larger in tinnitus than control groups at both probe frequencies under baseline conditions, decreased after masking in all conditions, and did not relate to RI. These results suggest that aberrant neural activity occurring in the TFR of A1 underlies tinnitus and its modulation during RI. They indicate further that while neural changes occur in A2 in tinnitus, these changes do not reflect the tinnitus percept. Models for tinnitus and forward masking are described that integrate these findings within a common framework.