Auditory language comprehension: an event-related fMRI study on the processing of syntactic and lexical information

The functional specificity of different brain regions recruited in auditory language processing was investigated by means of event-related functional magnetic resonance imaging (fMRI) while subjects listened to speech input varying in the presence or absence of semantic and syntactic information. There were two sentence conditions containing syntactic structure, i.e., normal speech (consisting of function and content words), syntactic speech (consisting of function words and pseudowords), and two word-list conditions, i.e., real words and pseudowords. The processing of auditory language, in general, correlates with significant activation in the primary auditory cortices and in adjacent compartments of the superior temporal gyrus bilaterally. Processing of normal speech appeared to have a special status, as no frontal activation was observed in this case but was seen in the other three conditions. This difference may point toward a certain automaticity of the linguistic processes used during normal speech comprehension. When considering the three other conditions, we found that these were correlated with activation in both left and right frontal cortices. An increase of activation in the planum polare bilaterally and in the deep portion of the left frontal operculum was found exclusively when syntactic processes were in focus. Thus, the present data may be taken to suggest an involvement of the left frontal and bilateral temporal cortex when processing syntactic information during comprehension.     

No evidence for qualitative differences in the processing of short and long temporal intervals

Several lines of research suggest that two distinct timing mechanisms are involved in temporal information processing: a sensory mechanism for processing of durations in the range of milliseconds and a cognitively controlled mechanism for processing of longer durations. The present study employed a dual-task approach and a sensory interference paradigm to further elucidate the distinct timing hypothesis. Experiment 1 used mental arithmetic as a nontemporal secondary task, Experiment 2 a memory search task, and Experiment 3 a visuospatial memory task. In Experiment 4, a loudness manipulation was applied. Mental arithmetic and loudness manipulation affected temporal discrimination of both brief and long intervals, whereas the two remaining tasks did not influence timing performance. Observed differences in interference patterns may be explained by some tasks being more difficult than others. The overall pattern of results argues against two qualitatively distinct timing mechanisms, but is consistent with attention-based cognitive models of human timing.     

On the role of verbalization during task set selection: Switching or serial order control?

Recent task-switching work in which paper-and-pencil administered single-task lists were compared with task-alternation lists has demonstrated large increases in task-switch costs with concurrent articulatory suppression (AS), implicating a crucial role for verbalization during switching (Baddeley, Chincotta, & Adlam, 2001; Emerson & Miyake, 2003). Experiment 1 replicated this result, using computerized assessment, albeit with much smaller effect sizes than in the original reports. In Experiment 2, AS interference was reduced when a sequential cue (spatial location) that indicated the current position in the sequence of task alternations was given. Finally, in Experiment 3, switch trials and no-switch trials were compared within a block of alternating runs of two tasks. Again, AS interference was obtained mainly when the endogenous sequencing demand was high, and it was comparable for no-switch and switch trials. These results suggest that verbalization may be critical for endogenous maintenance and updating of a sequential plan, rather than exclusively for the actual switching process.     

Intentions determine the effect of invisible metacontrast-masked primes: evidence for top-down contingencies in a peripheral cuing task

In 5 experiments, the authors tested whether the processing of nonconscious spatial stimulus information depends on a prior intention. This test was conducted with the metacontrast dissociation paradigm. Experiment 1 demonstrated that masked primes that could not be discriminated above chance level affected responses to the visible stimuli that masked them. Experiments 2 and 3 showed that this effect was abolished when the task instruction was changed in such a way that the primes ceased to be task relevant. Experiments 4 and 5 demonstrated that a prime's effect depended on whether it was associated with the same response as the target or with an opposite response.     

Sensory sensitivity, attachment experiences, and rejection responses among adults with borderline and avoidant features

Both avoidant and borderline personality disorder (APD and BPD) are theoretically associated with temperamental vulnerabilities, adverse attachment experiences, and negative (pessimistic or catastrophic) reactions to the threat of perceived rejection; however, more work is needed to differentiate how these processes account for the etiology and maintenance of both disorders. In this study, 156 adults completed questionnaires measuring APD and BPD features, temperament (sensory-processing sensitivity), mood, and attachment experiences. A vignette task was devised to examine pessimistic cognitive-affective reactions in situations signaling potential rejection. Both APD and BPD were associated with temperamental sensitivity, but BPD was uniquely linked with a subscale measuring sensitivity to mental and emotive stimuli, whereas APD was uniquely linked with a subscale measuring the control and avoidance of aversive stimulation. Compared to APD, BPD was more strongly linked with negative moods (anxiety, anger, sadness) and insecure attachment to parents, whereas APD was more strongly linked (than BPD) to pessimistic cognitive-affective responses to rejection-related situations.     

Conflict, consciousness, and control

To what degree is executive conflict resolution dependent on conflict awareness? A recent study by Dehaene et al. compared neural responses to conflict elicited through either visible or subliminal primes. Despite behavioral conflict effects for both prime types, neural activity in a control network including the anterior cingulate cortex (ACC) was present only for visible primes. Along with other recent results, these findings have important implications for theories on the relationship between ACC, consciousness, and cognitive control.     

Peripheral cuing by abrupt-onset cues: the influence of color in S-R corresponding conditions

Research on visuospatial attention indicates that a peripheral abrupt-onset cue at target position (valid condition) facilitates processing of the target, whereas a cue at another position interferes. This validity effect seems to be contingent on a similarity of the cue's color to the set of target colors (cf. J. Exp. Psychol.: Human Percep. Perform. 18 (1992) 1030). In Experiments 1-3, we confirm this contingency with cues that have the potential to activate responses. Thus, attentional capture and response capture are apparently governed by the same principle. In Experiment 2, it is demonstrated that color priming is not responsible for the contingency. In Experiment 3, it is shown that a more efficient reallocation of attention after color-dissimilar cues than after color-similar cues might contribute to the contingency.     

Threshold estimation in two-alternative forced-choice (2AFC) tasks: the Spearman-Kärber method

The Spearman-K?rber method can be used to estimate the threshold value or difference limen in two-alternative forced-choice tasks. This method yields a simple estimator for the difference limen and its standard error, so that both can be calculated with a pocket calculator. In contrast to previous estimators, the present approach does not require any assumptions about the shape of the true underlying psychometric function. The performance of this new nonparametric estimator is compared with the standard technique of probit analysis. The Spearman-K?rber method appears to be a valuable addition to the toolbox of psychophysical methods, because it is most accurate for estimating the mean (i.e., absolute and difference thresholds) and dispersion of the psychometric function, although it is not optimal for estimating percentile-based parameters of this function.     

Effects of redundant visual stimuli on temporal order judgments

Four experiments were conducted in order to compare the effects of stimulus redundancy on temporal order judgments (TOJs) and reaction times (RTs). In Experiments 1 and 2, participants were presented in each trial with a tone and either a single visual stimulus or two redundant visual stimuli. They were asked to judge whether the tone or the visual display was presented first. Judgments of the relative onset times of the visual and the auditory stimuli were virtually unaffected by the presentation of redundant, rather than single, visual stimuli. Experiments 3 and 4 used simple RT tasks with the same stimuli, and responses were much faster to redundant than to single visual stimuli. It appears that the traditional speedup of RT associated with redundant visual stimuli arises after the stimulus detection processes to which TOJs are sensitive.