scholarly journals Event-related potentials reflect prediction errors and pop-out during comprehension of degraded speech

2020 ◽  
Author(s):  
Leah Banellis ◽  
Rodika Sokoliuk ◽  
Conor J Wild ◽  
Howard Bowman ◽  
Damian Cruse

AbstractComprehension of degraded speech requires higher-order expectations informed by prior-knowledge. Accurate top-down expectations of incoming degraded speech cause a subjective semantic “pop-out” or conscious breakthrough experience. Indeed, the same stimulus can be perceived as meaningless when no expectations are made in advance. We investigated the ERP correlates of these top-down expectations, their error signals, and the subjective pop-out experience in healthy participants. We manipulated expectations in a word-pair priming noise-vocoded speech task and investigated the role of top-down expectation with a between-groups attention manipulation. Consistent with the role of expectations in comprehension, repetition priming significantly enhanced perceptual intelligibility of the noise-vocoded degraded targets for attentive participants. An early ERP was larger for mismatched (i.e. unexpected) targets than matched targets, indicative of an initial error signal not reliant on top-down expectations. Subsequently, a P3a-like ERP was larger to matched targets than mismatched targets only for attending participants - i.e. a pop-out effect. Rather than relying on complex post hoc interactions between prediction error and precision to explain this apredictive pattern, we consider our data to be consistent with prediction error minimisation accounts for early stages of processing followed by Global Neuronal Workspace-like breakthrough and processing in service of task goals.

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Leah Banellis ◽  
Rodika Sokoliuk ◽  
Conor J Wild ◽  
Howard Bowman ◽  
Damian Cruse

Abstract Comprehension of degraded speech requires higher-order expectations informed by prior knowledge. Accurate top-down expectations of incoming degraded speech cause a subjective semantic ‘pop-out’ or conscious breakthrough experience. Indeed, the same stimulus can be perceived as meaningless when no expectations are made in advance. We investigated the event-related potential (ERP) correlates of these top-down expectations, their error signals and the subjective pop-out experience in healthy participants. We manipulated expectations in a word-pair priming degraded (noise-vocoded) speech task and investigated the role of top-down expectation with a between-groups attention manipulation. Consistent with the role of expectations in comprehension, repetition priming significantly enhanced perceptual intelligibility of the noise-vocoded degraded targets for attentive participants. An early ERP was larger for mismatched (i.e. unexpected) targets than matched targets, indicative of an initial error signal not reliant on top-down expectations. Subsequently, a P3a-like ERP was larger to matched targets than mismatched targets only for attending participants—i.e. a pop-out effect—while a later ERP was larger for mismatched targets and did not significantly interact with attention. Rather than relying on complex post hoc interactions between prediction error and precision to explain this apredictive pattern, we consider our data to be consistent with prediction error minimization accounts for early stages of processing followed by Global Neuronal Workspace-like breakthrough and processing in service of task goals.


2020 ◽  
Author(s):  
Consuelo Vidal-Gran ◽  
Rodika Sokoliuk ◽  
Howard Bowman ◽  
Damian Cruse

AbstractPerception is facilitated by a hierarchy of expectations generated from context and prior knowledge. In auditory processing, violations of local (within-trial) expectations elicit a mismatch negativity, while violations of global (across-trial) expectations elicit a later positive component (P300). This result is taken as evidence of prediction errors ascending through the expectation hierarchy. However, in language comprehension, there is no evidence that violations of semantic expectations across local-global levels similarly elicit a sequence of hierarchical error signals – thus drawing into question the putative link between event-related potentials and prediction errors. We investigated the neural basis of such hierarchical expectations of semantics in a word-pair priming paradigm. By manipulating the overall proportion of related or unrelated word-pairs across the task, we created two global contexts that differentially encouraged strategic use of primes. Across two experiments, we replicated behavioural evidence of greater priming in the high validity context, reflecting strategic expectations of upcoming targets based on ‘global’ context. In our pre-registered EEG analyses, we observed a ‘local’ prediction error ERP effect (i.e. semantic priming) approximately 250ms post-target, which, in exploratory analyses, was followed 100ms later by a signal that interacted with the global context. However, the later effect behaved in an apredictive manner - i.e. was most extreme for fulfilled expectations, rather than violations. Our results are consistent with interpretations of early ERPs as reflections of prediction error and later ERPs as processes related to conscious access and in support of task demands.Significance statementSemantic expectations have been associated with the ERP N400 component, which is modulated by semantic prediction errors across levels of the hierarchy. However, there is no evidence of a two-stage profile that reflects violations of semantic expectations at a single level of the hierarchy, such as the MMN and P3b observed in the local-global paradigm, which are elicited by violations of local and global expectations, respectively. In the present study, we provided evidence of an early ERP effect that reflects violations of local semantic expectations, followed by an apredictive signal that interacted with the global context. Thus, these results support the notion of early ERPs as prediction errors and later ERPs reflecting conscious access and strategic use of context.


2016 ◽  
Vol 116 (3) ◽  
pp. 1396-1407 ◽  
Author(s):  
Yadira Roa Romero ◽  
Julian Keil ◽  
Johanna Balz ◽  
Jürgen Gallinat ◽  
Daniel Senkowski

Our brain generates predictions about forthcoming stimuli and compares predicted with incoming input. Failures in predicting events might contribute to hallucinations and delusions in schizophrenia (SZ). When a stimulus violates prediction, neural activity that reflects prediction error (PE) processing is found. While PE processing deficits have been reported in unisensory paradigms, it is unknown whether SZ patients (SZP) show altered crossmodal PE processing. We measured high-density electroencephalography and applied source estimation approaches to investigate crossmodal PE processing generated by audiovisual speech. In SZP and healthy control participants (HC), we used an established paradigm in which high- and low-predictive visual syllables were paired with congruent or incongruent auditory syllables. We examined crossmodal PE processing in SZP and HC by comparing differences in event-related potentials and neural oscillations between incongruent and congruent high- and low-predictive audiovisual syllables. In both groups event-related potentials between 206 and 250 ms were larger in high- compared with low-predictive syllables, suggesting intact audiovisual incongruence detection in the auditory cortex of SZP. The analysis of oscillatory responses revealed theta-band (4–7 Hz) power enhancement in high- compared with low-predictive syllables between 230 and 370 ms in the frontal cortex of HC but not SZP. Thus aberrant frontal theta-band oscillations reflect crossmodal PE processing deficits in SZ. The present study suggests a top-down multisensory processing deficit and highlights the role of dysfunctional frontal oscillations for the SZ psychopathology.


2007 ◽  
Vol 40 (05) ◽  
Author(s):  
AH Neuhaus ◽  
TE Goldberg ◽  
Y Hassoun ◽  
JA Bates ◽  
KW Nassauer ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Irina Chamine ◽  
Barry S. Oken

Objective. Stress-reducing therapies help maintain cognitive performance during stress. Aromatherapy is popular for stress reduction, but its effectiveness and mechanism are unclear. This study examined stress-reducing effects of aromatherapy on cognitive function using the go/no-go (GNG) task performance and event related potentials (ERP) components sensitive to stress. The study also assessed the importance of expectancy in aromatherapy actions.Methods. 81 adults were randomized to 3 aroma groups (active experimental, detectable, and undetectable placebo) and 2 prime subgroups (prime suggesting stress-reducing aroma effects or no-prime). GNG performance, ERPs, subjective expected aroma effects, and stress ratings were assessed at baseline and poststress.Results. No specific aroma effects on stress or cognition were observed. However, regardless of experienced aroma, people receiving a prime displayed faster poststress median reaction times than those receiving no prime. A significant interaction for N200 amplitude indicated divergent ERP patterns between baseline and poststress for go and no-go stimuli depending on the prime subgroup. Furthermore, trends for beneficial prime effects were shown on poststress no-go N200/P300 latencies and N200 amplitude.Conclusion. While there were no aroma-specific effects on stress or cognition, these results highlight the role of expectancy for poststress response inhibition and attention.


2014 ◽  
Vol 19 (1) ◽  
pp. 1-18 ◽  
Author(s):  
EDITH KAAN ◽  
JOSEPH KIRKHAM ◽  
FRANK WIJNEN

According to recent views of L2-sentence processing, L2-speakers do not predict upcoming information to the same extent as do native speakers. To investigate L2-speakers’ predictive use and integration of syntactic information across clauses, we recorded event-related potentials (ERPs) from advanced L2-learners and native speakers while they read sentences in which the syntactic context did or did not allow noun-ellipsis (Lau, E., Stroud, C., Plesch, S., & Phillips, C. (2006). The role of structural prediction in rapid syntactic analysis. Brain and Language, 98, 74–88.) Both native and L2-speakers were sensitive to the context when integrating words after the potential ellipsis-site. However, native, but not L2-speakers, anticipated the ellipsis, as suggested by an ERP difference between elliptical and non-elliptical contexts preceding the potential ellipsis-site. In addition, L2-learners displayed a late frontal negativity for ungrammaticalities, suggesting differences in repair strategies or resources compared with native speakers.


Author(s):  
Michiel Van Elk ◽  
Harold Bekkering

We characterize theories of conceptual representation as embodied, disembodied, or hybrid according to their stance on a number of different dimensions: the nature of concepts, the relation between language and concepts, the function of concepts, the acquisition of concepts, the representation of concepts, and the role of context. We propose to extend an embodied view of concepts, by taking into account the importance of multimodal associations and predictive processing. We argue that concepts are dynamically acquired and updated, based on recurrent processing of prediction error signals in a hierarchically structured network. Concepts are thus used as prior models to generate multimodal expectations, thereby reducing surprise and enabling greater precision in the perception of exemplars. This view places embodied theories of concepts in a novel predictive processing framework, by highlighting the importance of concepts for prediction, learning and shaping categories on the basis of prediction errors.


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