88 research outputs found

    Temporal regularity effects on pre-attentive and attentive processing of deviance

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    Temporal regularity allows predicting the temporal locus of future information thereby potentially facilitating cognitive processing. We applied event-related brain potentials (ERPs) to investigate how temporal regularity impacts pre-attentive and attentive processing of deviance in the auditory modality. Participants listened to sequences of sinusoidal tones differing exclusively in pitch. The inter-stimulus interval (ISI) in these sequences was manipulated to convey either isochronous or random temporal structure. In the pre-attentive session, deviance processing was unaffected by the regularity manipulation as evidenced in three event-related-potentials (ERPs): mismatch negativity (MMN), P3a, and reorienting negativity (RON). In the attentive session, the P3b was smaller for deviant tones embedded in irregular temporal structure, while the N2b component remained unaffected. These findings confirm that temporal regularity can reinforce cognitive mechanisms associated with the attentive processing of deviance. Furthermore, they provide evidence for the dynamic allocation of attention in time and dissociable pre-attentive and attention-dependent temporal processing mechanisms

    When temporal prediction errs:ERP responses to delayed action-feedback onset

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    Sensory suppression effects observed in electroencephalography (EEG) index successful predictions of the type and timing of self-generated sensory feedback. However, it is unclear how precise the timing prediction of sensory feedback is, and how temporal delays between an action and its sensory feedback affect perception. The current study investigated how prediction errors induced by delaying tone onset times affect the processing of sensory feedback in audition. Participants listened to self-generated (via button press) or externally generated tones. Self-generated tones were presented either without or with various delays (50, 100, or 250 ms; in 30% of trials). Comparing listening to externally generated and self-generated tones resulted in action-related P50 amplitude suppression to tones presented immediately or 100 ms after the button press. Subsequent ERP responses became more sensitive to the type of delay. Whereas the comparison of actual and predicted sensory feedback (N1) tolerated temporal uncertainty up to 100 ms, P2 suppression was modulated by delay in a graded manner: suppression decreased with an increase in sensory feedback delay. Self-generated tones occurring 250 ms after the button press additionally elicited an enhanced N2 response. These findings suggest functionally dissociable processes within the forward model that are affected by the timing of sensory feedback to self-action: relative tolerance of temporal delay in the P50 and N1, confirming previous results, but increased sensitivity in the P2. Further, they indicate that temporal prediction errors are treated differently by the auditory system: only delays that occurred after a temporal integration window (∼100 ms) impact the conscious detection of altered sensory feedback

    Emotional salience but not valence impacts anterior cingulate cortex conflict processing

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    Stimuli that evoke emotions are salient, draw attentional resources, and facilitate situationally appropriate behavior in complex or conflicting environments. However, negative and positive emotions may motivate different response strategies. For example, a threatening stimulus might evoke avoidant behavior, whereas a positive stimulus may prompt approaching behavior. Therefore, emotional stimuli might either elicit differential behavioral responses when a conflict arises or simply mark salience. The present study used functional magnetic resonance imaging to investigate valence-specific emotion effects on attentional control in conflict processing by employing an adapted flanker task with neutral, negative, and positive stimuli. Slower responses were observed for incongruent than congruent trials. Neural activity in the dorsal anterior cingulate cortex was associated with conflict processing regardless of emotional stimulus quality. These findings confirm that both negative and positive emotional stimuli mark salience in both low (congruent) and high (incongruent) conflict scenarios. Regardless of the conflict level, emotional stimuli deployed greater attentional resources in goal directed behavior

    About time:Ageing influences neural markers of temporal predictability

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    Timing abilities help organizing the temporal structure of events but are known to change systematically with age. Yet, how the neuronal signature of temporal predictability changes across the age span remains unclear. Younger (n = 21; 23.1 years) and older adults (n = 21; 68.5 years) performed an auditory oddball task, consisting of isochronous and random sound sequences. Results confirm an altered P50 response in the older compared to younger participants. P50 amplitudes differed between the isochronous and random temporal structures in younger, and for P200 in the older group. These results suggest less efficient sensory gating in older adults in both isochronous and random auditory sequences. N100 amplitudes were more negative for deviant tones. P300 amplitudes were parietally enhanced in younger, but not in older adults. In younger participants, the P50 results confirm that this component marks temporal predictability, indicating sensitive gating of temporally regular sound sequences.</p

    Auditory Predictions and Prediction Errors in Response to Self-Initiated Vowels.

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    It has been suggested that speech production is accomplished by an internal forward model, reducing processing activity directed to self-produced speech in the auditory cortex. The current study uses an established N1-suppression paradigm comparing self- and externally initiated natural speech sounds to answer two questions: (1) Are forward predictions generated to process complex speech sounds, such as vowels, initiated via a button press? (2) Are prediction errors regarding self-initiated deviant vowels reflected in the corresponding ERP components? Results confirm an N1-suppression in response to self-initiated speech sounds. Furthermore, our results suggest that predictions leading to the N1-suppression effect are specific, as self-initiated deviant vowels do not elicit an N1-suppression effect. Rather, self-initiated deviant vowels elicit an enhanced N2b and P3a compared to externally generated deviants, externally generated standard, or self-initiated standards, again confirming prediction specificity. Results show that prediction errors are salient in self-initiated auditory speech sounds, which may lead to more efficient error correction in speech production

    Facilitating Inter-Domain Synergies in Ambient Assisted Living Environments

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    Current Ambient Assisted Living (AAL) environments lack integration of sensors and actuators of other sub-domains. Creating technical and organizational integration is addressed by the BASIS project (Build Automation by a Scalable and Intelligent System), which aims to build a cross-domain home bus system. The main objective of this paper is to present an overview of design, architecture and state of realization of BASIS by describing the requirements development process, underlying hardware design and software architecture. We built a distributed system of one independent building manager with several redundantly meshed segment controllers, each controlling a bus segment with any number of bus nodes. The software system layer is divided into logical partitions representing each sub-domain. Structured data storage is possible with a special FHIR based home centered data warehouse. The system has been implemented in six apartments running under daily living conditions. BASIS integrates a broad range of sub-domains, which poses challenges to all project partners in terms of a common terminology, and project management methods, but enables development of inter-domain synergies like using the same sensor and actuator hardware for a broad range of services and use cases

    The impact of basal ganglia lesions on sensorimotor synchronization, spontaneous motor tempo, and the detection of tempo changes

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    a b s t r a c t The basal ganglia (BG) are part of extensive subcortico-cortical circuits that are involved in a variety of motor and non-motor cognitive functions. Accumulating evidence suggests that one specific function that engages the BG and associated cortico-striato-thalamo-cortical circuitry is temporal processing, i.e., the mechanisms that underlie the encoding, decoding and evaluation of temporal relations or temporal structure. In the current study we investigated the interplay of two processes that require precise representations of temporal structure, namely the perception of an auditory pacing signal and manual motor production by means of finger tapping in a sensorimotor synchronization task. Patients with focal lesions of the BG and healthy control participants were asked to align finger taps to tone sequences that either did or did not contain a tempo acceleration or tempo deceleration at a predefined position, and to continue tapping at the final tempo after the pacing sequence had ceased. Performance in this adaptive synchronization-continuation paradigm differed between the two groups. Selective damage to the BG affected the abilities to detect tempo changes and to perform attention-dependent error correction, particularly in response to tempo decelerations. An additional assessment of preferred spontaneous, i.e., unpaced but regular, production rates yielded more heterogeneous results in the patient group. Together these findings provide evidence for less efficient processing in the perception and the production of temporal structure in patients with focal BG lesions. The results also support the functional role of the BG system in attention-dependent temporal processing

    The Functional Role of Neural Oscillations in Non-Verbal Emotional Communication

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    Effective interpersonal communication depends on the ability to perceive and interpret nonverbal emotional expressions from multiple sensory modalities. Current theoretical models propose that visual and auditory emotion perception involves a network of brain regions including the primary sensory cortices, the superior temporal sulcus (STS), and orbitofrontal cortex (OFC). However, relatively little is known about how the dynamic interplay between these regions gives rise to the perception of emotions. In recent years, there has been increasing recognition of the importance of neural oscillations in mediating neural communication within and between functional neural networks. Here we review studies investigating changes in oscillatory activity during the perception of visual, auditory, and audiovisual emotional expressions, and aim to characterize the functional role of neural oscillations in nonverbal emotion perception. Findings from the reviewed literature suggest that theta band oscillations most consistently differentiate between emotional and neutral expressions. While early theta synchronization appears to reflect the initial encoding of emotionally salient sensory information, later fronto-central theta synchronization may reflect the further integration of sensory information with internal representations. Additionally, gamma synchronization reflects facilitated sensory binding of emotional expressions within regions such as the OFC, STS, and, potentially, the amygdala. However, the evidence is more ambiguous when it comes to the role of oscillations within the alpha and beta frequencies, which vary as a function of modality (or modalities), presence or absence of predictive information, and attentional or task demands. Thus, the synchronization of neural oscillations within specific frequency bands mediates the rapid detection, integration, and evaluation of emotional expressions. Moreover, the functional coupling of oscillatory activity across multiples frequency bands supports a predictive coding model of multisensory emotion perception in which emotional facial and body expressions facilitate the processing of emotional vocalizations

    The role of the medial geniculate body of the thalamus in the pathophysiology of tinnitus and implications for treatment

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    Tinnitus is an auditory sensation in the absence of actual external stimulation. Different clinical interventions are used in tinnitus treatment, but only few patients respond to available options. The lack of successful tinnitus treatment is partly due to the limited knowledge about the mechanisms underlying tinnitus. Recently, the auditory part of the thalamus has gained attention as a central structure in the neuropathophysiology of tinnitus. Increased thalamic spontaneous firing rate, bursting activity and oscillations, alongside an increase of GABAergic tonic inhibition have been shown in the auditory thalamus in animal models of tinnitus. In addition, clinical neuroimaging studies have shown structural and functional thalamic changes with tinnitus. This review provides a systematic overview and discussion of these observations that support a central role of the auditory thalamus in tinnitus. Based on this approach, a neuromodulative treatment option for tinnitus is proposed
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