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

While it is commonly agreed upon that language comprehenders preactivate information at multiple levels, there is less consensus regarding what and when information is predicted, under which circumstances, and via which mechanism(s). Regarding when, Ito, Corley, Pickering, Martin, & Nieuwland (2016) concluded that during sentence processing, word form-unlike semantic-preactivation crucially relies on the time available to generate late-stage predictions via language production mechanisms, setting this limit between 500 and 700 ms/word. The current event-related brain potential (ERP) study tests this proposal at a substantially faster serial visual presentation (SVP) rate of four words/s, on par with normal reading. We utilize the experimental design and replicate the general ERP findings of the two words/s SVP study of DeLong, Chan, & Kutas (2019), with results showing similar N400 reductions to unpredictable sentence continuations whether semantically or orthographically related to contextually predictable words, as well as an increased late posterior positivity to orthographic neighbors. These findings indicate that processing of written word information can be rapidly facilitated through context-based expectancies, establishing that if there is a time constraint for word form preactivation, it must be far less than limits specified by the prediction-by-production comprehension model championed by Ito et al.

An exploratory data analysis of word form prediction during word-by-word reading.

In 2005, we reported evidence indicating that upcoming phonological word forms-e.g., kite vs. airplane-were predicted during reading. We recorded brainwaves (electroencephalograms [EEGs]) as people read word-by-word and then correlated the predictability in context of indefinite articles that preceded nouns ( a kite vs. an airplane) with the average event-related brain potentials (ERPs) they elicited [K. A. DeLong, T. P. Urbach, M. Kutas, Nat. Neurosci. 8, 1117-1121 (2005)]. Amid a broader controversy about the role of word-form prediction in comprehension, those findings were recently challenged by a failed putative direct replication attempt [M. S. Nieuwland et al., eLife 7, e33468 (2018); nine labs, one experiment, and 2.6e4 observations]. To better understand the empirical justification for positing an association between prenominal article predictability and scalp potentials, we conducted a wide-ranging exploratory data analysis (EDA), pooling our original data with extant data from two followup studies (one lab, three experiments, and 1.2e4 observations). We modeled the time course of article predictability in the single-trial data by fitting linear mixed-effects regression (LMER) models at each time point and scalp location spanning a 3-s interval before, during, and after the article. Model comparisons based on Akaike information criteria (AIC) and slope-regression ERPs [rERPs; N. J. Smith, M. Kutas, Psychophysiology 52, 157-168 (2015)] provide substantial empirical support for a small positive association between article predictability and scalp potentials approximately 300 to 500 ms after article onset, predominantly over bilateral posterior scalp. We think this effect may reasonably be attributed to prediction of upcoming word forms.

Dopaminergic hypo-activity and reduced theta-band power in autism spectrum disorder: A resting-state EEG study.

BACKGROUND: Prior studies using a variety of methodologies have reported inconsistent dopamine (DA) findings in individuals with autism spectrum disorder (ASD), ranging from dopaminergic hypo- to hyper-activity. Theta-band power derived from scalp-recorded electroencephalography (EEG), which may be associated with dopamine levels in frontal cortex, has also been shown to be atypical in ASD. The present study examined spontaneous eye-blink rate (EBR), an indirect, non-invasive measure of central dopaminergic activity, and theta power in children with ASD to determine: 1) whether ASD may be associated with atypical DA levels, and 2) whether dopaminergic dysfunction may be associated with aberrant theta-band activation. METHOD: Participants included thirty-two children with ASD and thirty-two age-, IQ-, and sex-matched typically developing (TD) children. Electroencephalography and eye-tracking data were acquired while participants completed an eyes-open resting-state session. Blinks were counted and EBR was determined by dividing blink frequency by session duration and theta power (4-7.5 Hz) was extracted from midline leads. RESULTS: Eye-blink rate and theta-band activity were significantly reduced in children with ASD as compared to their TD peers. For all participants, greater midline theta power was associated with increased EBR (related to higher DA levels). CONCLUSIONS: These results suggest that ASD may be associated with dopaminergic hypo-activity, and that this may contribute to atypical theta-band power. Lastly, EBR may be a useful tool to non-invasively index dopamine levels in ASD and could potentially have many clinical applications, including selecting treatment options and monitoring treatment response.

Similar time courses for word form and meaning preactivation during sentence comprehension.

Current psycholinguistic research generally acknowledges that aspects of sentence comprehension benefit from neural preactivation of different types of information. However, despite strong support from a number of studies, routine specific word form preactivation has been challenged by Ito, Corley, Pickering, Martin, and Nieuwland (2016). They suggest that word form prediction is contingent upon having enough processing time and resources (afforded by slower input rates) to progress through unidirectional, productionlike stages of comprehension to arrive at word forms via semantic feature preactivation. This conclusion is based on findings from their ERP study, which used a related anomaly paradigm and reported form preactivation at a slow (700 ms) word presentation rate but not a faster one (500 ms). The present experimental design is a conceptual replication of Ito et al. (2016), testing young adults by measuring ERP amplitudes to unpredictable words related either semantically/associatively or orthographically to predictable sentence continuations, relative to unrelated continuations. Results showed that, at a visual presentation rate of two words per second, both types of related words show similarly reduced N400s, as well as varying degrees of increased posterior post-N400 positivity. These findings indicate that word form preactivation during sentence comprehension is detectable along a similar time course as semantic feature preactivation, and such processing does not necessarily require additional time beyond that afforded by near-normal reading rates.

Evaluating the Performance of Non-Hair SSVEP-Based BCIs Featuring Template-Based Decoding Methods.

Our previous study has demonstrated the feasibility of employing non-hair-bearing electrodes to build a Steadystate Visual Evoked Potential (SSVEP)-based Brain-Computer Interface (BCI) system, relaxing technical barriers in preparation time and offering an ease-of-use apparatus. The signal quality of the SSVEPs and the resultant performance of the non-hair BCI, however, did not close upon those reported in the state-of-the-art BCI studies based on the electroencephalogram (EEG) measured from the occipital regions. Recently, advanced decoding algorithms such as task-related component analysis have made a breakthrough in enhancing the signal quality of the occipital SSVEPs and the performance of SSVEP-based BCIs in a well-controlled laboratory environment. However, it remains unclear if the advanced decoding algorithms can extract highfidelity SSVEPs from the non-hair EEG and enhance the practicality of non-hair BCIs in real-world environments. This study aims to quantitatively evaluate whether, and if so, to what extent the non-hair BCIs can leverage the state-of-art decoding algorithms. Eleven healthy individuals participated in a 5-target SSVEP BCI experiment. A high-density EEG cap recorded SSVEPs from both hair-covered and non-hair-bearing regions. By evaluating and demonstrating the accessibility of nonhair-bearing behind-ear signals, our assessment characterized constraints on data length, trial numbers, channels, and their relationships with the decoding algorithms, providing practical guidelines to optimize SSVEP-based BCI systems in real-life applications.

Temporal dynamics of the consistency effect in reading Chinese: an event-related potentials study.

This study aimed to explore the temporal dynamics of the consistency effect in reading Chinese phonograms. High-consistency and low-consistency characters were used in the homophone judgment task, and the event-related potentials were recorded. The data showed that low-consistency characters elicited greater N170 amplitude in the temporal-occipital region and greater P200 amplitude in the frontal region than high-consistency characters, whereas high-consistency characters showed greater amplitude of the N400 negativity than low-consistency characters. These findings can be interpreted as indicating that low-consistency characters produce a greater activation for the initial analysis of the orthographical and phonological representations, whereas high-consistency characters involve a greater lexical competition in the later stage.