Testing limits: ERP evidence for word form preactivation during speeded sentence reading.

Emotion and attention: event-related brain potential studies

Recent behavioral and event-related brain potential (ERP) studies have revealed cross-modal interactions in endogenous spatial attention between vision and audition, plus vision and touch. The present ERP study investigated whether these interactions reflect supramodal attentional control mechanisms, and whether similar cross-modal interactions also exist between audition and touch. Participants directed attention to the side indicated by a cue to detect infrequent auditory or tactile targets at the cued side. The relevant modality (audition or touch) was blocked. Attentional control processes were reflected in systematic ERP modulations elicited during cued shifts of attention. An anterior negativity contralateral to the cued side was followed by a contralateral positivity at posterior sites. These effects were similar whether the cue signaled which side was relevant for audition or for touch. They also resembled previously observed ERP modulations for shifts of visual attention, thus implicating supramodal mechanisms in the control of spatial attention. Following each cue, single auditory, tactile, or visual stimuli were presented at the cued or uncued side. Although stimuli in task-irrelevant modalities could be completely ignored, visual and auditory ERPs were nevertheless affected by spatial attention when touch was relevant, revealing cross-modal interactions. When audition was relevant, visual ERPs, but not tactile ERPs, were affected by spatial attention, indicating that touch can be decoupled from cross-modal attention when task-irrelevant.

Processing of complex morphosyntactic structures in French: ERP evidence from native speakers

On why Collet's doubts regarding the PCA are misplaced

Dynamics of processing invisible faces in the brain: Automatic neural encoding of facial expression information

Recent studies reported that the detection of changes in the visual stimulation results in distraction of cognitive processing. From event-related brain potentials it was argued that distraction is triggered by the automatic detection of deviants. We tested whether distraction effects are confined to the detection of a deviation or can be triggered by changes per se, namely by rare stimuli that were not deviant with respect to the stimulation. The results obtained comparable early event-related brain potential effects for rare and deviant stimuli, suggesting an automatic detection of these changes. In contrast, behavioral distraction and attention-related event-related brain potential components were confined to deviant stimuli. This finding suggests that deviancy from a given standard adds a genuine contribution to distraction.

Results from recent event-related brain potential (ERP) studies investigating brain processes involved in the detection and analysis of emotional facial expression are reviewed. In all experiments, emotional faces were found to trigger an increased ERP positivity relative to neutral faces. The onset of this emotional expression effect was remarkably early, ranging from 120 to 180ms post-stimulus in different experiments where faces were either presented at fixation or laterally, and with or without non-face distractor stimuli. While broadly distributed positive deflections beyond 250ms post-stimulus have been found in previous studies for non-face stimuli, the early frontocentrally distributed phase of this emotional positivity is most likely face-specific. Similar emotional expression effects were found for six basic emotions, suggesting that these effects are not primarily generated within neural structures specialised for the automatic detection of specific emotions. Expression effects were eliminated when attention was directed away from the location of peripherally presented emotional faces, indicating that they are not linked to pre-attentive emotional processing. When foveal faces were unattended, expression effects were attenuated, but not completely eliminated. It is suggested that these ERP correlates of emotional face processing reflect activity within a neocortical system where representations of emotional content are generated in a task-dependent fashion for the adaptive intentional control of behaviour. Given the early onset of the emotion-specific effects reviewed here, it is likely that this system is activated in parallel with the ongoing evaluation of emotional content in the amygdala and related subcortical brain circuits.

Perspective taking modulates event-related potentials to perceived pain

Auditory event-related brain potentials (ERPs) were recorded to tones of different frequencies and locations in a dichotic selective attention task in which Ss responded to occasional deviant tones of a prespecified location and frequency. Attention effects were isolated as negative difference (Nd) waves by subtracting ERPs to tones with no attended features from ERPs to the same tones when they shared target frequency, location, or both cues. The N1/P90 (latency 80-100 ms), originating in a tonotopically organized generator, was enhanced for all tones in the attended ear. Nd waves, beginning at 80 ms and lasting up to 700 ms, were seen to tones with either attended feature. Nd waves to frequency and location features had different scalp distributions consistent with generation in different cortical fields. Conjunction-specific Nds began 30-50 ms after Nds to individual features. The relative timing suggests that feature conjunction began before the analysis of individual features was complete.

An event-related brain potential (ERP) study comparing descriptive and evaluative judgment processes is reported. Using identical stimuli to isolate perceptual from judgmental processes, the two judgment types were operationalized by employing symmetry and aesthetic judgments. Electrophysiological activity was recorded while participants viewed newly designed two-dimensional patterns in a pre-cued task setting. Judgment analyses of a Phase I test and performance in the main experiment revealed detailed paramorphic models of the individual judges' cognitive systems as well as group models. Symmetry showeda strong positive correlation with judgments and was the most important cue in every case. Descriptive judgments were performed faster than evaluative judgments. The ERPs revealed a phasic frontal negativity in the non-aesthetic condition as well as a sustained posterior negativity in the symmetrical condition. All conditions showed late positive potentials (LPP). Evaluative judgment LPPs revealed a more pronounced right lateralization. It was concluded that descriptive symmetry judgment and evaluative aesthetic judgment processes differ dramatically and recruit, at least in part, different neural machinery.

Theoretically, stimuli can be related to the self as subject (“I”) or object (“ME”) of experience. This event-related brain potential (ERP) study investigated whether listening to personal and possessive pronouns elicits different modes of self-processing regarding time-course and neural sources. Going beyond previous research, first (1PP) and second person (2PP) pronouns were included to determine the specificity of self-processing. Participants listened passively to German pronouns while the electroencephalogram was recorded. Modulation of ERPs revealed a processing advantage for the 2PP personal pronoun “du” (“you”) already in early time windows. Regarding possessive pronouns, N1 amplitudes indicated increased attention orientation to the 1PP pronoun “mein” (“my”), whereas during later time windows, processing of 1PP and 2PP possessive pronouns did not differ but differed from the third person pronoun “sein” (“his”). ERP source imaging suggests that primary sensory brain regions (auditory cortex), the insula and cortical midline structures are differentially involved into these two processing modes. The results support the idea of distinct self-processing modes (“I” and “ME”) and confirm their dynamic nature. Moreover, they demonstrate that on a neural level neither “I” or “ME” are invariantly tied to the first person, in line with the hypothesis that self-processing is relational and context-dependent.

Older FMR1 premutation carriers may develop fragile X-associated tremor/ataxia syndrome (FXTAS), a neurodegenerative disorder manifesting cognitive deficits that often subsequently progress to dementia. To date, there is no specific treatment available for FXTAS. Studies have demonstrated the premutation-associated overactivation of glutamatergic receptors in neurons. Memantine, a NMDA receptor antagonist approved for treatment of Alzheimer's disease, thus was tested in the first placebo-controlled, double-blind, randomized clinical trial in FXTAS. Prior event-related brain potential (ERP) studies in FXTAS found reduced N400 repetition effect, a glutamate-related electrophysiological marker of semantic priming, and verbal memory processes. This substudy of the randomized clinical trial of memantine in FXTAS sought to use the N400 repetition effect to evaluate effects of chronic memantine treatment on verbal memory. Subsequent recall and recognition memory tests for the experimental stimuli were administered to characterize verbal memory. Data from 41 patients who completed the 1-year memantine trial (21 on memantine) and also completed longitudinal ERP studies were analyzed. Results showed treatment-associated benefits on both cued-recall memory and N400 repetition effect amplitude. Importantly, improvement in cued recall was positively correlated with amplitude increase of the N400 repetition effect. The placebo group, in contrast, displayed a significant reduction of the N400 repetition effect after 1 year. These results suggest that memantine treatment may have beneficial effects on verbal memory in FXTAS. Additional studies of memantine, perhaps in combination with other therapeutic agents, appear warranted, as symptomatic treatments and neuroprotective treatments are both needed for this recently recognized neurodegenerative disorder.

The amplitudes of the event-related brain potentials (ERPs) have been associated with the amount of attentional resources. The present study investigated whether force production type (increasing or decreasing force) in a visuomotor force tracking task modulates the ERPs elicited in a somatosensory oddball task performed simultaneously, whether stimulus-response coupling assessed by a single-trial analysis of P300 latency is modulated by the concurrent performance of the tasks, and whether dynamic visuomotor coordination rather static coordination is sensitive to the ERP modulation. In the dual-task condition, the subjects tracked a target line moving on the display with another line representing the force generated by the grip of their left hand, while executing the somatosensory oddball task with the right hand. In the oddball-only condition, the oddball task only was performed. The amplitude of the P300 elicited in the oddball task was decreased in the dual-task condition compared with the oddball-only condition, and further decreased in the force-decreasing phase compared with the increasing phase, but was not altered by the concurrently performed isometric contraction. P100, N140, reaction time (RT), and error rate were not influenced by force production type. A correlation analysis of single-trial P300 latency and RT showed that the dual-task condition produced a stronger coupling of the P300 and RT. In summary, different force production types requiring dynamic visuomotor coordination alter a modality-nonspecific late stage of somatosensory processing but have less of an effect on early stages. During the performance of the dual task, stimulus-response coupling in the somatosensory discrimination task becomes stronger to compensate for a lack of resources and/or due to snap decisions owing to sufficient resources.

The present event-related brain potential (ERP) study investigates mechanisms underlying the processing of morphosyntactic information during real-time auditory sentence comprehension in French. Employing an auditory-visual sentence-picture matching paradigm, we investigated two types of anomalies using entirely grammatical auditory stimuli: (i) semantic mismatches between visually presented actions and spoken verbs, and (ii) number mismatches between visually presented agents and corresponding morphosyntactic number markers in the spoken sentences (determiners, pronouns in liaison contexts, and verb-final “inflection”). We varied the type and amount of number cues available in each sentence using two manipulations. First, we manipulated the verb type, by using verbs whose number cue was audible through subject (clitic) pronoun liaison (liaison verbs) as well as verbs whose number cue was audible on the verb ending (consonant-final verbs). Second, we manipulated the pre-verbal context: each sentence was preceded either by a neutral context providing no number cue, or by a subject noun phrase containing a subject number cue on the determiner. Twenty-two French-speaking adults participated in the experiment. While sentence judgment accuracy was high, participants' ERP responses were modulated by the type of mismatch encountered. Lexico-semantic mismatches on the verb elicited the expected N400 and additional negativities. Determiner number mismatches elicited early anterior negativities, N400s and P600s. Verb number mismatches elicited biphasic N400-P600 patterns. However, pronoun + verb liaison mismatches yielded this pattern only in the plural, while consonant-final changes did so in the singular and the plural. Furthermore, an additional sustained frontal negativity was observed in two of the four verb mismatch conditions: plural liaison and singular consonant-final forms. This study highlights the different contributions of number cues in oral language processing and is the first to investigate whether auditory-visual mismatches can elicit errors reminiscent of outright grammatical errors. Our results emphasize that neurocognitive mechanisms underlying number agreement in French are modulated by the type of cue that is used to identify auditory-visual mismatches.

This article reviews cognitive neuroscience research on visual and language processing to suggest an analogy between the neural interpolation mechanisms in perceptual processing and the constructive processes that underlie meaning construction in language. Traditional models of language comprehension as a decoding process are argued to involve an overattribution of the import of linguistic information, and an overly narrow view of the role of background and contextual knowledge. A review of a number of event-related brain potential (ERP) studies of language comprehension reveals an early sensitivity in the brain response to global contextual factors. These findings are consistent with a view of linguistic information as prompting meaning construction processes such as the activation of frames, the establishment of mappings, and the integration or blending of information from different domains.