Identifying the Null Subject: Evidence from Event-Related Brain Potentials

Event-related brain potentials (ERPs) were recorded during spoken language comprehension to study the on-line effects of gender agreement violations in controlled infinitival complements. Spanish sentences were constructed in which the complement clause contained a predicate adjective marked for syntactic gender. By manipulating the gender of the antecedent (i.e., the controller) of the implicit subject while holding constant the gender of the adjective, pairs of grammatical and ungrammatical sentences were created. The detection of such a gender agreement violation would indicate that the parser had established the coreference relation between the null subject and its antecedent. The results showed a complex biphasic ERP (i.e., an early negativity with prominence at anterior and central sites, followed by a centroparietal positivity) in the violating condition as compared to the non-violating conditions. The brain reacts to NP-adjective gender agreement violations within a few hundred milliseconds of their occurrence. The data imply that the parser has properly coindexed the null subject of an infinitive clause with its antecedent.     

Event-Related Potentials Related to Normal and Morphed Emotional Faces

S. Bentin and L. Y. Deouell (2000) have suggested that face recognition is achieved through a special-purpose neural mechanism, and its existence can be identified by a specific event-related potential (ERP) correlate, the N170 effect. In the present study, the authors explored the structural significance of N170 by comparing normal vs. morphed stimuli. They used a morphing procedure that allows a fine modification of some perceptual details (first-order relations). The authors also aimed to verify the independence of face identification from other cognitive mechanisms, such as comprehension of emotional facial expressions, by applying an emotion-by-emotion analysis to examine the emotional effect on N170 ERP variation. They analyzed the peak amplitude and latency variables in the temporal window of 120-180 ms. The ERP correlate showed a classic N170 ERP effect, more negative and more posteriorly distributed for morphed faces compared with normal faces. In addition, they found a lateralization effect, with a greater right-side distribution of the N170, but not directly correlated to the morphed or normal conditions. Two cognitive codes, structural and expression, are discussed, and the results are compared with the multilevel model proposed by V. Bruce and A. W. Young (1986, 1998).     

Brain Slow Potentials and Postural Sway Behavior During Sharpshooting Performance

In the present study, the relation of preparatory brain slow potentials (SPs) to postural body sway during sharpshooting performance was examined. SPs from frontal, left-central, and right-central areas were recorded from 6 elite and 6 non-elite sharpshooters during a realistic simulated shooting task. A force platform technique was used in the recording of postural sway. The results showed that body sway, as indexed by sway amplitude and mean velocity, was associated with the concomitant SP changes. That relationship was dependent on the shooter's expertise level, however. The main finding among the elite shooters was that the reduced amplitude of body sway coincided with reduced frontal positivity, whereas in the non-elite shooters, the amplitude of sway and the mean sway velocity in the anteroposterior direction were typically accompanied by the lateralization of central negativity. Those findings offer some new insights for evaluating the functional significance of preparatory brain SPs associated with psychomotor processing in sharpshooting. The results from the present study also have implications for the understanding of the postural strategies employed by shooters of different expertise levels.     

The Time Course of Grammatical and Phonological Processing During Speaking: Evidence from Event-Related Brain Potentials

Motor-related brain potentials were used to examine the time course of grammatical and phonological processes during noun phrase production in Dutch. In the experiments, participants named colored pictures using a no-determiner noun phrase. On half of the trials a syntactic–phonological classification task had to be performed before naming. Depending on the outcome of the classifications, a left or a right push-button response was given (go trials), or no push-button response was given (no-go trials). Lateralized readiness potentials (LRPs) were derived to test whether syntactic and phonological information affected the motor system at separate moments in time. The results showed that when syntactic information determined the response-hand decision, an LRP developed on no-go trials. However, no such effect was observed when phonological information determined response hand. On the basis of the data, it can be estimated that an additional period of at least 40 ms is needed to retrieve a word's initial phoneme once its lemma has been retrieved. These results provide evidence for the view that during speaking, grammatical processing precedes phonological processing in time.     

Different Anaphoric Expressions Are Investigated by Event-Related Brain Potentials

Event-related potentials were recorded to substantiate the claim of a distinct psycholinguistic status of (a) pronouns vs. proper names and (b) ellipses vs. proper names. In two studies 41 students read sentences in which the number of intervening words between the anaphor and its antecedent was either small or large. Comparing the far with the near distance condition revealed anaphor resolution specific effects: Ellipses triggered a potential shift with a short latency (approximately 120-200 ms) and with a fronto-central scalp distribution while pronouns and proper names triggered one with a longer latency (approximately 360-440 ms) and a parietal to right-occipital distribution. The early effect resembled the left-anterior negativity which has been related to syntax processing, while the latter resembled an N400 which is assumed to reflect semantic integration processes. These findings support the idea that ellipses and pronouns/proper names are processed by distinct mechanisms being implemented in distinct cortical cell assemblies.     

Event-Related Brain Potentials during Identification of Tachistoscopically Presented Pictures

In the present study in 20 healthy subjects, event-related potentials (ERPs) were used to investigate the identification of picture stimuli. Each of 36 landscape pictures and 36 scrambled pictures was presented by a tachistoscope repeatedly until the subject made an identification response. Presentation of one picture was finished after 12 exposures. On the average, landscapes were identified after 5.8 ± 0.4 exposures; identification responses to scrambles were always wrong and occurred after 11.8 ± 0.1 exposures. Latencies and amplitude measures were assessed for P2, P3, N400, and the slow wave (SW). Changes in P2 across stimulus presentations did not differ between landscapes and scrambles excluding this component from being indicative for the processing of stimulus meaning. Amplitude of P3 generally declined across presentations, but increased prior to identification for landscape pictures. N400 rapidly declined across presentations of landscapes, but less rapidly for scrambles. The SW increased across stimulus presentations. This increase was more pronounced for landscape than scrambled pictures. The pattern of ERP changes can be interpreted in a framework of a stepwise inhibition of spreading activation within semantic memory with progressing picture identification.     

Estimating and Testing the Sources of Evoked Potentials in the Brain

The source of an event related brain potential (ERP) is estimated from multivariate measurements of this ERP on the head under several mathematical and physical constraints on the parameters of the source model. We will discuss statistical aspects of standard methods to estimate these parameters and their confidence intervals. In addition new principled tests of the goodness of fit as well as of differences between estimated sources are proposed and compared with customary approaches in psychophysiology. Several factors which influence the statistical analysis, in particular the number of measurement leads, will be discussed.     

Stutterers and others: A comparison of communication attitudes

The Erickson 39-item S-scale was administered to 24 persons who stutter, 24 persons with voice or articulation disorders, and 24 normal speakers. The purpose of the study was to determine if the three populations differed in communication attitude. The one-way analysis of variance showed that the three groups differed significantly. Normal speakers revealed the most desirable communication attitude; the communication attitude of the voice and articulation disorders population was less favorable than normals; the communication attitude of the stuttering population was least favorable.     

Mechanisms of Priming by Masked Stimuli: Inferences From Event-Related Brain Potentials

A metacontrast procedure was combined with the recording of event-related potentials (ERPs) to examine the mechanisms underlying the priming effect exerted by masked visual stimuli (primes) on target processing. Participants performed spatially arranged choice responses to stimulus locations. The relationship between prime and target locations (congruity) and the mapping between target and response locations (compatibility) were factorially manipulated. Although participants were unaware of prime locations, choice responses were faster for congruent than incongruent conditions irrespective of the mapping. Visual ERP components and the onset of the lateralized readiness potential (LRP), an index of specific motor activation, revealed that neither perceptual nor preselection processes contributed to the congruity effect. However, the LRP waveform indicated that primes activated responses that fit the stimulus-response mapping. These results support the view that sensorimotor processing of masked stimuli is functionally distinct from their conscious perception.     

Different Brain Wave Patterns and Cortical Control Abilities in Relation to Different Creative Potentials

Contemporary understanding of brain functions provides a way to probe into the mystery of creativity. However, the prior evidence regarding the relationship between creativity and brain wave patterns reveals inconsistent conclusions. One possible reason might be that the means of selecting creative individuals in the past has varied in each study. By distinguishing creative potential as open-ended versus closed-ended based on theoretical views, this study examined different brain wave patterns and cortical control abilities in relation to different creative potentials by using electroencephalogram (EEG) biofeedback equipment. The results demonstrated that participants’ performance on the open-ended creative problem was positively related to EEG alpha frequencies, whereas performance on the closed-ended creative problem was related to larger variability in EEG dynamics between alpha and beta waves when performing either open-ended or closed-ended creativity tasks. Further, better control in changing states of brain wave activities according to the EEG biofeedback signals could predict closed-ended creativity performance. Open-ended creativity was related only to the enhancement of alpha signals. These results help clarify previous inconsistent findings, reveal different natures of distinct creativities, and further suggest ways to improve different aspects of creativity with modified biofeedback procedures.     

Psychopathy and Event-Related Brain Potentials (ERPs) associated with attention to speech stimuli

Event-related brain potentials (ERPs) were used to determine whether low left-hemisphere arousal or unusual cortical responses to speech stimuli might be associated with anomalies in language function that reportedly occur when psychopaths perform lateralized information-processing tasks. ERPs to phonemic stimuli were recorded while 11 psychopathic (P) and 13 nonpsychopathic (NP) male prison inmates performed a Single-Task and a Dual-Task. In the Single-Task, a speech discrimination ‘oddball’ paradigm, the subject was required to respond whenever a target stimulus (the less frequent of two phonemes) occured. In the Dual-Task, he had to respond to target stimuli while simultaneously performing a perceptual-motor (distractor) task. There were no group differences in ERP measures of central arousal (N100) during performance of the Single- and Dual-Tasks. For both groups, the P300 component of the ERP to the target stimulus was smaller and had longer latency during the Dual-Task than during the Single-Task, indicating that in the Dual-Task phonemic discrimination and the perceptual-motor task completed for similar perceptual resources. Overlapping Group P's P300 responses to the target stimulus during the Dual-Task was a vertex and asymmetric (left-hemisphere) positive slow wave (SW), suggesting unusual speech processing in psychopaths under conditions of distraction, perhaps related to reduced sensitivity to the sequential probabilities associated with events presented in an auditory channel. The results were consistent with the hypothesis that psychopaths have limited left-hemisphere resources for processing linguistic stimuli.     

粤语-普通话双言者和普通话单言者周期性时间推理比较

通过4个实验,考察粤-普双言者与普通话单言者周期性时间推理的差异。实验1和2表明,无论时间以5为单位、不以5为单位还是以“字”为单位,双言者反应时均显著长。实验3和4表明,当时间为以5为单位时,双言者与单言者均采用数字加工方式;当材料以“字”为单位时,双言者采用空间表象加工方式。     

Spontaneous Imitation of Fundamental Frequency and Speech Rate by Nonstutterers and Stutterers

Speech can be described either in terms of acoustics, as a perceptual outcome, or as a motor event. Central to theories of speech perception and production is an attempt to describe how these aspects of speech are interrelated. The present experiment investigated how the nonstutterers' and stutterers' reproductions of acoustically presented interrogative sentences were influenced by experimental variations of intonation (sentence initial vs. sentence final) and speech rate (normal vs. time compressed). We studied the effects of these stimulus manipulations on the speech rate and fundamental frequency (F₀ ) of 10 adult German-speaking nonstutterers and seven stutterers. Experimental manipulations of intonation and speech rate significantly influenced the syllable duration and speech rate of both normal speakers and stutterers. The fundamental frequency of the subjects' responses were also significantly influenced by the intonation of the stimulus. But the stutterers' increase in F₀ for stressed syllables was generally less pronounced than that of nonstutterers. These results imply that (a) the subjects not only extract linguistic meaning from intonation but that they also store extragrammatical speech rate information, and (b) the speakers adopt these speech rate variations for their own productions. Generally, these results demonstrate that speech perception is not limited to extracting linguistically invariant information. The results show that speakers actively generate their own prosody and that this generative process is influenced by the prosodic structure of another speaker's antecedent speech. The implications of these results for theories of speech production are discussed.     

Motor Performance of Stutterers and Nonstutterers on Timing and Force Control Tasks

Recently it has been suggested that speech and manual timing tasks share a common central process (Franz, Zelaznik, & Smith, 1992). Because stuttering is thought to be related to deficits in motoric processes such as timing, stutterers (n = 15) were compared with a set of age-, education-, and sex-matched nonstutterers on timing and isometric force-production tasks. In the timing tasks, subjects flexed and extended the right index finger at the metacarpophalangeal joint at cycle durations of 600, 500, 400, 300, and 200 ms. In the force-production tasks, subjects generated isometric forces to match target force levels displayed on a cathode-ray tube (CRT) screen. There were five levels of force, ranging from .11 to 7.85 newtons. Overall, there were no differences in timing and force-production performance between stutterers and nonstutterers. These results are similar to those obtained recently by Hulstijn, Summers, van Lieshout, and Peters (1992). We suggest that stuttering is not characterized by a general deficit in rhythmic timing. Instead, the motor deficit associated with stuttering should be viewed as speech specific.     

Working Memory Effects of Gap-Predictions in Normal Adults: An Event-Related Potentials Study

The current study examined the relationship between verbal memory span and the latency with which a filler-gap dependency is constructed. A previous behavioral study found that low span listeners did not exhibit antecedent reactivation at gap sites in relative clauses, in comparison to high verbal memory span subjects (Roberts et?al. in J Psycholinguist Res 36(2):175-188, 2007), which suggests that low span subjects are delayed at gap filling. This possibility was examined in the current study. Using an event-related potentials paradigm, it was found that low span subjects have an onset latency delay of about 200?ms in brain responses to violations of syntactic expectancies after the gap site, thus providing a time course measure of the delay hypothesized by previous literature.     

Flexing Gender Perception: Brain Potentials Reveal the Cognitive Permeability of Grammatical Information

A growing body of recent research suggests that verbal categories, particularly labels, impact categorization and perception. These findings are commonly interpreted as demonstrating the involvement of language on cognition; however, whether these assumptions hold true for grammatical structures has yet to be investigated. In the present study, we investigated the extent to which linguistic information, namely, grammatical gender categories, structures cognition to subsequently influence categorical judgments and perception. In a nonverbal categorization task, French–English bilinguals and monolingual English speakers made gender-associated judgments about a set of image pairs while event-related potentials were recorded. The image sets were composed of an object paired with either a female or male face, wherein the object was manipulated for their conceptual gender relatedness and grammatical gender congruency to the sex of the following target face. The results showed that grammatical gender modulated the N1 and P2/VPP, as well as the N300 exclusively for the French–English bilinguals, indicating the inclusion of language in the mechanisms associated with attentional bias and categorization. In contrast, conceptual gender information impacted the monolingual English speakers in the later N300 time window given the absence of a comparable grammatical feature. Such effects of grammatical categories in the early perceptual stream have not been found before, and further provide grounds to suggest that language shapes perception.     

Orthographically Influenced Abstract Phonological Representation: Evidence from Non-rhotic Speakers

It is typically assumed that when orthography is translated silently into phonology (i.e., when reading silently), the phonological representation is equivalent to the spoken form or, at least, the surface phonemic form. The research presented here demonstrates that the phonological representation is likely to be more abstract than this, and is orthographically influenced. For example, the claim is made that the word corn has an underlying /r/ in its phonological representation, even in non-rhotic dialects. The evidence comes from difficulties observed in judgements about the homophony with a target word of a pseudohomophone whose phonology does not match the putative abstract representation of that word. For example, it is hard to say that the pseudohomophone cawn is homophonic with corn. The conclusion that orthography can shape phonological representation is antithetical to both computational models of the conversion of print to sound and linguistic accounts of phonology.The research reported in this paper was supported by a grant awarded to the author by the Australian Research Council.     

Interpreting What Speakers Say and Implicate

The traditional view in pragmatic theory is that a distinction exists between what speakers say and what they mean, communicate, or implicate in context. For example, when uttering Jane has three children, a speaker might only say that "Jane has three children but may have more than three," but the speaker implicates that "Jane has exactly three children." Under this view, pragmatics plays only a small role in determining what speakers say and has a primary part in interpreting speaker's intended messages. My aim in this article is to challenge this view. I describe empirical work showing that pragmatics has a fundamental role in determining both what speakers say and implicate. Thus, when a speaker utters Jane has three children, enriched pragmatic information is used to infer that the speaker says "Jane has exactly three children" and that in specific contexts, the speaker can go on to express additional pragmatic meanings, such as "Jane is married" or "Jane is very busy because she has three children." I also describe work on the importance of complex pragmatic, metarepresentational reasoning in understanding irony and metaphor. Finally, I briefly discuss the relevance of these new developments in pragmatics for neurolinguistic research.