Event-related Potential Responses Research Articles

Smartphone-based ear-electroencephalography to study sound processing in everyday life.

In everyday life, people differ in their sound perception and thus sound processing. Some people may be distracted by construction noise, while others do not even notice. With smartphone-based mobile ear-electroencephalography (ear-EEG), we can measure and quantify sound processing in everyday life by analysing presented sounds and also naturally occurring ones. Twenty-four participants completed four controlled conditions in the lab (1h) and one condition in the office (3h). All conditions used the same paired-click stimuli. In the lab, participants listened to click tones under four different instructions: no task towards the sounds, reading a newspaper article, listening to an audio article or counting a rare deviant sound. In the office recording, participants followed daily activities while they were sporadically presented with clicks, without any further instruction. In the beyond-the-lab condition, in addition to the presented sounds, environmental sounds were recorded as acoustic features (i.e., loudness, power spectral density and sounds onsets). We found task-dependent differences in the auditory event-related potentials (ERPs) to the presented click sounds in all lab conditions, which underline that neural processes related to auditory attention can be differentiated with ear-EEG. In the beyond-the-lab condition, we found ERPs comparable to some of the lab conditions. The N1 amplitude to the click sounds beyond the lab was dependent on the background noise, probably due to energetic masking. Contrary to our expectation, we did not find a clear ERP in response to the environmental sounds. Overall, we showed that smartphone-based ear-EEG can be used to study sound processing of well defined-stimuli in everyday life.

Does the speaker's eye gaze facilitate infants' word segmentation from continuous speech? An ERP study.

The environment in which infants learn language is multimodal and rich with social cues. Yet, the effects of such cues, such as eye contact, on early speech perception have not been closely examined. This study assessed the role of ostensive speech, signalled through the speaker's eye gaze direction, on infants' word segmentation abilities. A familiarisation-then-test paradigm was used while electroencephalography (EEG) was recorded. Ten-month-old Dutch-learning infants were familiarised with audio-visual stories in which a speaker recited four sentences with one repeated target word. The speaker addressed them either with direct or with averted gaze while speaking. In the test phase following each story, infants heard familiar and novel words presented via audio-only. Infants' familiarity with the words was assessed using event-related potentials (ERPs). As predicted, infants showed a negative-going ERP familiarity effect to the isolated familiarised words relative to the novel words over the left-frontal region of interest during the test phase. While the word familiarity effect did not differ as a function of the speaker's gaze over the left-frontal region of interest, there was also a (not predicted) positive-going early ERP familiarity effect over right fronto-central and central electrodes in the direct gaze condition only. This study provides electrophysiological evidence that infants can segment words from audio-visual speech, regardless of the ostensiveness of the speaker's communication. However, the speaker's gaze direction seems to influence the processing of familiar words. RESEARCH HIGHLIGHTS: We examined 10-month-old infants' ERP word familiarity response using audio-visual stories, in which a speaker addressed infants with direct or averted gaze while speaking. Ten-month-old infants can segment and recognise familiar words from audio-visual speech, indicated by their negative-going ERP response to familiar, relative to novel, words. This negative-going ERP word familiarity effect was present for isolated words over left-frontal electrodes regardless of whether the speaker offered eye contact while speaking. An additional positivity in response to familiar words was observed for direct gaze only, over right fronto-central and central electrodes.

EEG-based Objective Quality Assessment of Interrupted Speech.

As an important dimension of speech degradation, interruption destroys the acoustic waveform information of a speech signal and seriously affects the quality rating in speech perception. Existing studies assessing the quality of interrupted speech mainly focus on subjective methods. This work used event-related potentials (ERPs) to objectively investigate the effects of two interruption factors (i.e., interruption duty cycle and interruption rate) on the perceived quality of the periodically interrupted speech. An oddball-paradigm based ERP experiment was designed, and the periodically interrupted stimuli were presented to participants in the ERP experiment. Meanwhile, participants were instructed to provide their subjective quality ratings of interrupted speech under the same interruption conditions. The experimental results showed that the degree of both interruption duty cycle and interruption rate affected the peak latency of mismatch negativity (MMN) of the collected ERP response, with a smaller MMN peak latency under conditions with a smaller interruption duty cycle or a larger interruption rate. These findings are largely consistent with the subjective quality rating results, suggesting that the peak latency of MMN response can be potentially used as an objective quality indicator of the periodically interrupted speech.

Neural signatures to prosocial and antisocial interactions in young infants.

Preverbal infants appear to be more attracted by prosocial characters and events, as typically assessed using preferential looking times and manual choice. However, infants' neural correlates of observed prosocial and antisocial interactions are still scarce. Here, we familiarized 5-month-old (N = 24) infants with a prosocial and antisocial scene (i.e., a character either helping or hindering) and infants' Event-Related Potentials (ERP) were recorded in response to the presentation of short video clips of the prosocial and antisocial interaction. On a neural level, results revealed that infants could discriminate between helping and hindering events at an early stage of processing, as shown by a larger N290 response to the former compared to the latter. Further, while the Nc - typically indexing attentional processes - was larger for antisocial over prosocial events, the LPP, indexing cognitive evaluation of the stimuli, was larger for prosocial over antisocial actions. Finally, infants' higher scores on the effortful control temperamental subscale were related to infants' increased N290 neural sensitivity to antisocial scenes. Together, these findings provide new evidence of the time course of infants' ERP responses during the observation of helping and hindering interactions, which involves both attentional and socially relevant processes.

Neural and Behavioral Differences in Speech Perception for Children With Autism Spectrum Disorders Within an Audiovisual Context.

Reduced use of visible articulatory information on a speaker's face has been implicated as a possible contributor to language deficits in autism spectrum disorders (ASD). We employ an audiovisual (AV) phonemic restoration paradigm to measure behavioral performance (button press) and event-related potentials (ERPs) of visual speech perception in children with ASD and their neurotypical peers to assess potential neural substrates that contribute to group differences. Two sets of speech stimuli, /ba/-"/a/" ("/a/" was created from the /ba/ token by a reducing the initial consonant) and /ba/-/pa/, were presented within an auditory oddball paradigm to children aged 6-13 years with ASD (n = 17) and typical development (TD; n = 33) within two conditions. The AV condition contained a fully visible speaking face; the pixelated (PX) condition included a face, but the mouth and jaw were PX, removing all articulatory information. When articulatory features were present for the /ba/-"/a/" contrast, it was expected that the influence of the visual articulators would facilitate a phonemic restoration effect in which "/a/" would be perceived as /ba/. ERPs were recorded during the experiment while children were required to press a button for the deviant sound for both sets of speech contrasts within both conditions. Button press data revealed that TD children were more accurate in discriminating between /ba/-"/a/" and /ba/-/pa/ contrasts in the PX condition relative to the ASD group. ERPs in response to the /ba/-/pa/ contrast within both AV and PX conditions differed between children with ASD and TD children (earlier P300 responses for children with ASD). Children with ASD differ in the underlying neural mechanisms responsible for speech processing compared with TD peers within an AV context.

Acoustic and Subjective Basis of Emotional Perception in Comatose Patients: A Comparative Study.

: The acoustic stimulation in consciousness patients may improve the diagnosis assessment and the effectiveness of rehabilitation procedures. We aimed to investigate the event-related potential (ERP) response to emotional auditory stimuli in comatose patients. : We measured the nonlinear and linear electroencephalogram (EEG) features, prepared the acoustic analysis of stimuli parameters, and assessed the subjective emotional rates of stimuli characteristics. : Patients with better outcomes had recognizable ERP responses and significant changes of the nonlinear EEG features to emotional sounds, unlike patients with worse outcomes. The response of comatose patients was attributed to acoustical features of emotional sounds, whereas the EEG response of healthy subjects was associated with their subjective feelings. The comatose patients demonstrated the variable EEG activity for neutral and emotional sounds. : Thus, the EEG reactivity followed the better outcome of comatose patients to emotional stimuli. The study assumed the substantial differences of emotional stimuli perception in the healthy and unconscious brain.

Visual recognition of identical cognates involves sublexical inhibition and lexical facilitation.

The study investigated the consequences of cross-language activation on the time course of bilingual word recognition. Twenty-two Spanish-English bilinguals and 21 English monolingual controls decided whether visually presented letter strings were English words, while behavioral and event-related potential responses were recorded. The language status of words was manipulated experimentally, such that words were either identical cognates between English and Spanish (e.g. CLUB) or noncognates (e.g. CLOCK). Participants were equally fast in responding to cognate and noncognate words. Bilinguals were more accurate in responding to cognates, whereas monolinguals exhibited higher accuracy in response to noncognates. Critically, bilinguals produced larger P200 followed by smaller N400 responses to cognates than noncognates, whereas monolinguals showed a pattern of reduced N400 responses to cognates. The results of the current study indicate that cross-language activation may not only result in lexical facilitation (indexed by a reduction of the N400 response to cognates) as a result of shared form-meaning associations across languages but also in sublexical inhibition (indexed by a larger P200 response to cognates) as a consequence of cross-language competition among phonological forms. Results support the language-nonselective view of bilingual lexical access and suggest that while lexical facilitation for identical cognates may be observed at most levels of second language proficiency, sublexical inhibition in response to identical cognates may be a marker of advanced levels of proficiency.

EEG signature of grouping strategies in numerosity perception.

The moment we see a group of objects, we can appreciate its numerosity. Our numerical estimates can be imprecise for large sets (>4 items), but they become much faster and more accurate if items are clustered into groups compared to when they are randomly displaced. This phenomenon, termed groupitizing, is thought to leverage on the capacity to quickly identify groups from 1 to 4 items (subitizing) within larger sets, however evidence in support for this hypothesis is scarce. The present study searched for an electrophysiological signature of subitizing while participants estimated grouped numerosities exceeding this range by measuring event-related potential (ERP) responses to visual arrays of different numerosities and spatial configurations. The EEG signal was recorded while 22 participants performed a numerosity estimation task on arrays with numerosities in the subitizing (3 or 4) or estimation (6 or 8) ranges. In the latter case, items could be spatially arranged into subgroups (3 or 4) or randomly scattered. In both ranges, we observed a decrease in N1 peak latency as the number of items increased. Importantly, when items were arranged to form subgroups, we showed that the N1 peak latency reflected both changes in total numerosity and changes in the number of subgroups. However, this result was mainly driven by the number of subgroups to suggest that clustered elements might trigger the recruitment of the subitizing system at a relatively early stage. At a later stage, we found that P2p was mostly modulated by the total numerosity in the set, with much less sensitivity for the number of subgroups these might be segregated in. Overall, this experiment suggests that the N1 component is sensitive to both local and global parcelling of elements in a scene suggesting that it could be crucially involved in the emergence of the groupitizing advantage. On the other hand, the later P2p component seems to be much more bounded to the global aspects of the scene coding the total number of elements while being mostly blind to the number of subgroups in which elements are parsed.

Current and lasting effects of affect labeling on late positive potential (LPP) amplitudes elicited by negative events.

Labeling the emotional aspect of self-unrelated stimuli (i.e., affect labeling) is a crucial strategy for implicit emotion regulation. However, it is uncertain whether affect labeling influences event-related potential (ERP) responses (e.g., the late positive potential, LPP) to negative stimuli in comparison with control conditions in which attention is shifted to the emotional content of the stimuli (e.g., affect matching). Additionally, it is unknown whether affect labeling has a lasting effect on the processing of negative stimuli. Participants were required to label the emotion (negative or neutral) of target pictures with two words, to match the emotion with alternative pictures or to merely view the target pictures. Target pictures were presented again immediately after the regulation task. After all the target pictures had been labeled, matched and viewed, the pictures were re-exposed for the third time. The results showed that negative pictures elicited larger late LPP responses during the affect labeling task than during other tasks. However, the LPP responses were smaller for negative pictures in the affect labeling condition than in the other conditions when target pictures were re-exposed immediately after the task. When target pictures were re-presented again long after the regulation tasks, the LPP responses were smaller for negative stimuli with a history of affect labeling than viewing, whereas this effect did not differ between the affect labeling and matching conditions. The current findings suggest that affect labeling has current effects and, to some extent, has lasting effects on negative stimulus processing.

Sensitivity to syllable stress regularities in externally but not self-triggered speech in Dutch.

Several theories of predictive processing propose reduced sensory and neural responses to anticipated events. Support comes from magnetoencephalography/electroencephalography (M/EEG) studies, showing reduced auditory N1 and P2 responses to self-generated compared to externally generated events, or when the timing and form of stimuli are more predictable. The current study examined the sensitivity of N1 and P2 responses to statistical speech regularities. We employed a motor-to-auditory paradigm comparing event-related potential (ERP) responses to externally and self-triggered pseudowords. Participants were presented with a cue indicating which button to press (motor-auditory condition) or which pseudoword would be presented (auditory-only condition). Stimuli consisted of the participant's own voice uttering pseudowords that varied in phonotactic probability and syllable stress. We expected to see N1 and P2 suppression for self-triggered stimuli, with greater suppression effects for more predictable features such as high phonotactic probability and first-syllable stress in pseudowords. In a temporal principal component analysis (PCA), we observed an interaction between syllable stress and condition for the N1, where second-syllable stress items elicited a larger N1 than first-syllable stress items, but only for externally generated stimuli. We further observed an effect of syllable stress on the P2, where first-syllable stress items elicited a larger P2. Strikingly, we did not observe motor-induced suppression for self-triggered stimuli for either the N1 or P2 component, likely due to the temporal predictability of the stimulus onset in both conditions. Taking into account previous findings, the current results suggest that sensitivity to syllable stress regularities depends on task demands.

Somatosensory Event-Related Potential as an Electrophysiological Correlate of Endogenous Spatial Tactile Attention: Prospects for Electrotactile Brain-Computer Interface for Sensory Training.

Tactile attention tasks are used in the diagnosis and treatment of neurological and sensory processing disorders, while somatosensory event-related potentials (ERP) measured by electroencephalography (EEG) are used as neural correlates of attention processes. Brain-computer interface (BCI) technology provides an opportunity for the training of mental task execution via providing online feedback based on ERP measures. Our recent work introduced a novel electrotactile BCI for sensory training, based on somatosensory ERP; however, no previous studies have addressed specific somatosensory ERP morphological features as measures of sustained endogenous spatial tactile attention in the context of BCI control. Here we show the morphology of somatosensory ERP responses induced by a novel task introduced within our electrotactile BCI platform i.e., the sustained endogenous spatial electrotactile attention task. By applying pulsed electrical stimuli to the two proximal stimulation hotspots at the user's forearm, stimulating sequentially the mixed branches of radial and median nerves with equal probability of stimuli occurrence, we successfully recorded somatosensory ERPs for both stimulation locations, in the attended and unattended conditions. Waveforms of somatosensory ERP responses for both mixed nerve branches showed similar morphology in line with previous reports on somatosensory ERP components obtained by stimulation of exclusively sensory nerves. Moreover, we found statistically significant increases in ERP amplitude on several components, at both stimulation hotspots, while sustained endogenous spatial electrotactile attention task is performed. Our results revealed the existence of general ERP windows of interest and signal features that can be used to detect sustained endogenous tactile attention and classify between spatial attention locations in 11 healthy subjects. The current results show that features of N140, P3a and P3b somatosensory ERP components are the most prominent global markers of sustained spatial electrotactile attention, over all subjects, within our novel electrotactile BCI task/paradigm, and this work proposes the features of those components as markers of sustained endogenous spatial tactile attention in online BCI control. Immediate implications of this work are the possible improvement of online BCI control within our novel electrotactile BCI system, while these finding can be used for other tactile BCI applications in the diagnosis and treatment of neurological disorders by employing mixed nerve somatosensory ERPs and sustained endogenous electrotactile attention task as control paradigms.

Event-related potentials in response to early terminated and completed sequential decision-making

The process of outcome evaluation effectively navigates subsequent choices in humans. However, it is largely unclear how people evaluate decision outcomes in a sequential scenario, as well as the neural mechanisms underlying this process. To address this research gap, the study employed a sequential decision task in which participants were required to make a series of choices in each trial, with the option to terminate their choices. Based on participants' decisions, two outcome patterns were classified: the “reached” condition and the “unreached” condition, and the event-related potentials (ERPs) were recorded. Further, in the unreached condition, we investigated how the distance (i.e., the position interval between the actual outcome and potential outcome) modulated outcome evaluation. Behavioral data showed a higher emotion rating when people got a reward rather than a loss (i.e., the reached condition), while the opposite was true in the unreached condition. ERP results showed a larger feedback-related negativity (FRN), a smaller P3, and a larger late positive potential (LPP) when people got a loss compared to a reward. Importantly, a hierarchical processing pattern was found in the unreached condition: people processed separately the potential outcome and the distance at the early stage, manifested in the FRN amplitude; subsequently, the brain focused on the distance—a lower distance elicited an enhanced P3 amplitude. Finally, the potential outcome and distance were processed interactively in the LPP amplitude. Overall, these findings shed light on the neural underpinnings of outcome evaluation in sequential decision-making.

Neural mechanisms of expert persuasion on willingness to pay for sugar.

Introduction: Sugar consumption is associated with many negative health consequences. It is, therefore, important to understand what can effectively influence individuals to consume less sugar. We recently showed that a healthy eating call by a health expert can significantly decrease the willingness to pay (WTP) for sugar-containing food. Here, we investigate which aspects of neural responses to the same healthy eating call can predict the efficacy of expert persuasion. Methods: Forty-five healthy participants performed two blocks of a bidding task, in which they had to bid on sugar-containing, sugar-free and non-edible products, while their electroencephalography (EEG) was recorded. In between the two blocks, they listened to a healthy eating call by a nutritionist emphasizing the risks of sugar consumption. Results: We found that after listening to the healthy eating call, participants significantly decreased their WTP for sugar-containing products. Moreover, a higher intersubject correlation of EEG (a measure of engagement) during listening to the healthy eating call resulted in a larger decrease in WTP for sugar-containing food. Whether or not a participant's valuation of a product was highly influenced by the healthy eating call could also be predicted by spatiotemporal patterns of EEG responses to the healthy eating call, using a machine learning classification model. Finally, the healthy eating call increased the amplitude of the P300 component of the visual event-related potential in response to sugar-containing food. Disussion: Overall, our results shed light on the neural basis of expert persuasion and demonstrate that EEG is a powerful tool to design and assess health-related advertisements before they are released to the public.

Neural correlates of attentional orienting with neutral and fearful gaze cues in 12-month-olds

ABSTRACT Infants use information on gaze direction and facial expressions for social referencing when encountering various objects in their environment. However, it remains unclear how these social cues influence attentional orienting in infants. Using event-related potentials (ERPs), we investigated the neural correlates of attentional orienting cued by an averted gaze with neutral and fearful expressions in 12-month-olds. We focused on the ERPs in response to a face (N290, P400, and Nc) as well as a saccade toward the target (the presaccadic spike potential: SP) and found that the amplitudes of the face-sensitive ERPs (N290 and P400) were larger for directed than averted gaze direction irrespective of facial expression. Furthermore, the amplitude of the SP involved in overt orienting was larger for fearful expressions than for neutral expressions, irrespective of gaze congruency. These results suggest that information on gaze direction and facial expression, specifically neutral and fearful expressions, may be processed independently, and that fearful expressions dominantly influence the neural correlates of attentional orienting in infants around 12 months of age.

The emotional facial recognition performance of Chinese patients with schizophrenia: An event-related potentials study

ABSTRACT Background: Patients with schizophrenia have deficits in identifying and recognizing emotional facial expressions. Aim: This study aimed to explore the event-related potential (ERP) responses of patients with schizophrenia (SZ) and healthy controls (HC) using the Chinese Facial Affective Picture System (CFAPS). Methods: This study included 30 SZs and 31 HCs. We asked them to complete the task based on the oddball paradigm, in which three emotional faces (happy, fearful, and neutral) were used as target stimuli. Additionally, the amplitude and latency of the N170 component and the P300 component were recorded synchronously. Results: Compared with HCs, SZs had significantly smaller amplitudes of N170 and P300 to all facial expressions. The pairwise comparison revealed that fearful faces could trigger a significantly larger P300 amplitude in HCs than neutral faces, while the such a difference was not found in SZs. Conclusion: These findings indicated that SZs had a noticeable deficiency in the structural coding of face recognition and available attentional resources.

The neurophysiological responses of music processing in bilingual teenagers

The association/dissociation between music and language processing has long been a matter of debate. Musicians and tonal language speakers are more sensitive to pitch differences than nonmusicians and nontonal language speakers. Bilingual experience modulates auditory processing of sounds, but it is unclear whether and how bilingual experience affects music processing. This study examines music processing in bilingual teenagers from Mandarin (a tonal language) households and those from non-tonal language households. The central question is whether bilingual experience enhances auditory processing similarly regardless of the specific language, or whether the influence of language on music processing is language specific. Event-related potential (ERP) responses were recorded from 65 scalp sites. An oddball paradigm with six types of music changes (intensity, pitch, rhythm, timbre, slide and location) was presented. Preliminary results did not support the general bilingual advantage theory, but did support the language-specific enhancement of auditory processing.

Event-related potential responses to differences in vibrotactile frequency: Evidence for continuous encoding of tactile information during early perception

Perception of vibrotactile frequency is driven by activation of different types of mechanoreceptors embedded in the skin, which respond to vibrations in a frequency range of approximately 0.4 to 500 Hz. While previous behavioral work has measured participants’ sensitivity to differences in vibration frequency, it is unclear how this information is encoded in neural representations during perception. This issue was addressed in an event-related potential (ERP) experiment investigating responses to vibrotactile stimuli. EEG data were recorded while participants rested their hand on a tactile transducer. On each trial, the transducer delivered a sinusoidal vibration with a duration of 1000 ms. Frequency of vibration ranged from 30 to 70 Hz in 10 Hz steps. Results revealed that frequency is encoded in early somatosensory ERP responses recorded at Cz. Specifically, the amplitude of a negative-going ERP component, centered at approximately 50 ms post-stimulus onset, increased as stimulus frequency increased from 40 to 70 Hz. These results demonstrate that vibrotactile frequency is encoded continuously during perception and that these responses can be measured using scalp-recorded EEG.

Reduction in right lateralized N2 error response to stroke order violations in poor Chinese word spellers: A study on event-related potential markers for Chinese reading and spelling

Stroke order knowledge is critical for Chinese reading and spelling acquisition. Previous studies have demonstrated enhancements of the N2 and P3 event-related potential (ERP) components at the Pz electrode to stroke order violations of Chinese characters in younger adults. However, it remained unclear whether similar ERP responses could be found in children. The current study investigated the ERP responses to stroke order violations of Chinese characters in children and examined the associations of the ERP responses with children’s Chinese reading and spelling performance. A total of 26 Grade 2 Hong Kong Chinese children observed stroke-by-stroke displays of Chinese characters and judged whether the Chinese characters were written in the correct order. The ERP results showed larger anterior N2 and posterior P3 at the midline electrodes to the incorrect strokes than to the correct strokes. In addition, a smaller right lateralized temporal N2 response to the incorrect strokes was found in poor spellers as compared with good spellers of Chinese. The effect of the right lateralized temporal N2 response on reading performance was fully mediated through spelling ability. These results demonstrated increases in the anterior N2 and posterior P3 responses to stroke order violation of Chinese characters in second graders and suggest the right lateralized N2 response as a potential neural marker of Chinese literacy development in children.

Vocal Emotion Recognition in Autism: Behavioral Performance and Event-Related Potential (ERP) Response.

Autistic youth display difficulties in emotion recognition, yet little research has examined behavioral and neural indices of vocal emotion recognition (VER). The current study examines behavioral and event-related potential (N100, P200, Late Positive Potential [LPP]) indices of VER in autistic and non-autistic youth. Participants (N=164) completed an emotion recognition task, the Diagnostic Analyses of Nonverbal Accuracy (DANVA-2) which includedVER, during EEG recording. The LPP amplitude was larger in response to high intensity VER, and social cognition predicted VER errors. Verbal IQ, not autism, was related to VER errors. An interaction between VER intensity and social communication impairments revealed these impairments were related to larger LPP amplitudes during low intensity VER. Taken together, differences in VER may be due to higher order cognitive processes, not basic, early perception (N100, P200), and verbal cognitive abilities may underlie behavioral, yet occlude neural, differences in VER processing.

Electrophysiological biomarkers and age characterize phenotypic heterogeneity among individuals with major depressive disorder.

Introduction: Despite the high need for effective treatments for major depressive disorder (MDD), the development of novel medicines is hampered by clinical, genetic and biological heterogeneity, unclear links between symptoms and neural dysfunction, and tenuous biomarkers for clinical trial contexts of use. Methods: In this study, we examined the International Study to Predict Optimized Treatment in Depression (iSPOT-D) clinical trial database for new relationships between auditory event-related potential (ERP) responses, demographic features, and clinical symptoms and behavior, to inform strategies for biomarker-driven patient stratification that could be used to optimize future clinical trial design and drug development strategy in MDD. Results: We replicate findings from previous analyses of the classic auditory oddball task in the iSPOT-D sample showing smaller than typical N1 and P300 response amplitudes and longer P300 latencies for target and standard stimuli in patients with MDD, suggesting altered bottom-up sensory and top-down attentional processes. We further demonstrate that age is an important contributor to clinical group differences, affecting both topographic distribution of the clinically informative ERP responses and the types of the stimuli sensitive to group differences. In addition, the observed brain-behavior associations indicate that levels of anxiety and stress are major contributing factors to atypical sensory and attentional processing among patients with MDD, particularly in the older subgroups. Discussion: Our novel findings support the possibility of accelerated cognitive aging in patients with MDD and identify the frontal P300 latency as an additional candidate biomarker of MDD. These results from a large, well-phenotyped sample support the view that heterogeneity of the clinical population with MDD can be systematically characterized based on age and neural biomarkers of sensory and attentional processing, informing patient stratification strategies in the design of clinical trials.