Sensorimotor synchronization with adaptively timed sequences

Most studies of human sensorimotor synchronization require participants to coordinate actions with computer-controlled event sequences that are unresponsive to their behavior. In the present research, the computer was programmed to carry out phase and/or period correction in response to asynchronies between taps and tones, and thereby to modulate adaptively the timing of the auditory sequence that human participants were synchronizing with, as a human partner might do. In five experiments the computer's error correction parameters were varied over a wide range, including "uncooperative" settings that a human synchronization partner could not (or would not normally) adopt. Musically trained participants were able to maintain synchrony in all these situations, but their behavior varied systematically as a function of the computer's parameter settings. Computer simulations were conducted to infer the human participants' error correction parameters from statistical properties of their behavior (means, standard deviations, auto- and cross-correlations). The results suggest that participants maintained a fixed gain of phase correction as long as the computer was cooperative, but changed their error correction strategies adaptively when faced with an uncooperative computer.     

Multiple temporal references in sensorimotor synchronization with metrical auditory sequences

A local phase perturbation in an auditory sequence during synchronized finger tapping elicits an automatic phase correction response (PCR). The stimulus for the PCR is usually considered to be the most recent tap-tone asynchrony. In this study, participants tapped on target tones ("beats") of isochronous tone sequences consisting of beats and subdivisions (1:n tapping). A phase perturbation was introduced either on a beat or on a subdivision. Both types of perturbation elicited a PCR, even though there was no asynchrony associated with a subdivision. Moreover, the PCR to a perturbed beat was smaller when an unperturbed subdivision followed than when there was no subdivision. The relative size of the PCRs to perturbed beats and subdivisions depended on tempo, on whether the subdivision was local or present throughout the sequence, and on whether or not participants engaged in mental subdivision, but not on whether or not taps were made on the subdivision level. The results show that phase correction in synchronization depends not merely on asynchronies but on perceptual monitoring of multiple temporal references within a metrical hierarchy.     

Circle graphs and monadic second-order logic

This article is part of a project consisting in expressing, whenever possible, graph properties and graph transformations in monadic second-order logic or in its extensions using modulo p cardinality set predicates or auxiliary linear orders. A circle graph is the intersection graph of a set of chords of a circle. Such a set is called a chord diagram. It can also be described by a word with two occurrences of each letter, called a double occurrence word. If a circle graph is prime for the split (or join) decomposition defined by Cunnigham, it has a unique representation by a chord diagram, and this diagram can be defined by monadic second-order formulas with the even cardinality set predicate. By using the (canonical) split decomposition of a circle graph, we define in monadic second-order logic with auxiliary linear orders all its chord diagrams. This construction uses the fact that the canonical split decomposition of a graph can be constructed in monadic second-order logic with help of an arbitrary linear order. We prove that the order of first occurrences of the letters in a double occurrence word w that represents a connected circle graph determines this word in a unique way. The word w can be defined by a monadic second-order formula from the word of first occurrences of letters. We also prove that a set of circle graphs has bounded clique-width if and only if all the associated chord diagrams have bounded tree-width.     

French normative data and naming times for action pictures

The aim of the present study was to provide French normative data for 112 action line drawings. The set of action pictures consisted of 71 drawings taken from Masterson and Druks (1998) and 41 additional drawings. It was standardized on six psycholinguistic variables—that is, name agreement, image agreement, image variability, visual complexity, conceptual familiarity, and age of acquisition (AoA). Naming latencies to the action pictures were collected, and a regression analysis was performed on the naming latencies, with the standardized variables, as well as with word frequency and length, taken as predictors. A reliable influence of AoA, name agreement, and image agreement on the naming latencies was observed. The findings are consistent with previous published studies in other languages. The full set of these norms may be downloaded fromwww.psychonomic.org/archive/.     

Inner and outer face perception in children with autism.

Possible peculiarities in face perception in the autistic population were explored through two experiments. Fourteen autistic children (mean age=10 years 1 month) were individually matched to verbal mental age (VMA) and chronological age (CA) subjects. In a first experiment, subjects were to match faces on the basis of either their outer (hair, chin, ears) or their inner (eyes, nose, mouth) aspects. Autistic children performed equally well in both conditions, while VMA-matched children performed better in the outer than the inner part condition. In a second experiment, chimeric faces consisting of the outer part of an individual's face and the inner part of another individual's face were presented to the subjects. None of the groups showed a preference for neither the outer nor the inner part of the face in this condition. Results were discussed in terms of the existence of a local visual processing strategy in this population.     

Assessing autobiographical memory: the web-based autobiographical Implicit Association Test

By assessing the association strength with TRUE and FALSE, the autobiographical Implicit Association Test (aIAT) [Sartori, G., Agosta, S., Zogmaister, C., Ferrara, S. D., &; Castiello, U. (2008). How to accurately detect autobiographical events. Psychological Science, 19, 772–780. doi:10.1111/j.1467-9280.2008.02156.x] aims to determine which of two contrasting statements is true. To efficiently run well-powered aIAT experiments, we propose a web-based aIAT (web-aIAT). Experiment 1 (n?=?522) is a web-based replication study of the first published aIAT study [Sartori, G., Agosta, S., Zogmaister, C., Ferrara, S. D., &; Castiello, U. (2008). How to accurately detect autobiographical events. Psychological Science, 19, 772–780. doi:10.1111/j.1467-9280.2008.02156.x; Experiment 1]. We conclude that the replication was successful as the web-based aIAT could accurately detect which of two playing cards participants chose (AUC?=?.88; Hit rate?=?81%). In Experiment 2 (n?=?424), we investigated whether the use of affirmative versus negative sentences may partly explain the variability in aIAT accuracy findings. The aIAT could detect the chosen card when using affirmative (AUC?=?.90; Hit rate?=?81%), but not when using negative sentences (AUC?=?.60; Hit rate?=?53%). The web-based aIAT seems to be a valuable tool to facilitate aIAT research and may help to further identify moderators of the test’s accuracy.     

Der psychogene Tod

Der psychogene Tod ist eine tückische Realit?t. Zum Thema folgen ein kleiner Ausschnitt und ein Fallbeispiel aus meinem Buch „Tod durch Vorstellungskraft“ [1].     

Emotion-induced impairments in speeded word recognition tasks

Recent studies show that emotional stimuli impair the identification of subsequently presented, briefly flashed stimuli. In the present study, we investigated whether emotional distractors (primes) impaired target processing when presentation of the target stimulus was not impoverished. In lexical decision, animacy decision, rhyme decision, and nonword naming, targets were presented in such a manner that they were clearly visible (i.e., targets were not masked and presented until participants responded). In all tasks taboo-sexual distractors caused a slowdown in responding to the subsequent neutral target. Our results indicate that the detrimental effects of emotional distractors are not confined to paradigms in which visibility of the target is limited. Moreover, impairments were obtained even when semantic processing of stimuli was not required.     

Emotion-induced trade-offs in spatiotemporal vision

It is generally assumed that emotion facilitates human vision in order to promote adaptive responses to a potential threat in the environment. Surprisingly, we recently found that emotion in some cases impairs the perception of elementary visual features (Bocanegra & Zeelenberg, 2009b). Here, we demonstrate that emotion improves fast temporal vision at the expense of fine-grained spatial vision. We tested participants' threshold resolution with Landolt circles containing a small spatial or brief temporal discontinuity. The prior presentation of a fearful face cue, compared with a neutral face cue, impaired spatial resolution but improved temporal resolution. In addition, we show that these benefits and deficits were triggered selectively by the global configural properties of the faces, which were transmitted only through low spatial frequencies. Critically, the common locus of these opposite effects suggests a trade-off between magno- and parvocellular-type visual channels, which contradicts the common assumption that emotion invariably improves vision. We show that, rather than being a general "boost" for all visual features, affective neural circuits sacrifice the slower processing of small details for a coarser but faster visual signal.