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Abstracts
  • Wackermann, J., Pacer, J., & Wittmann, M. (2014). Perception of acoustically presented time series with varied intervals. Acta Psychologica, 147, 105–110. https://doi.org/10.1016/j.actpsy.2013.09.015

    Data from three experiments on serial perception of temporal intervals in the supra-second domain are reported. Sequences of short acoustic signals ("pips") separated by periods of silence were presented to the observers. Two types of time series, geometric or alternating, were used, where the modulus 1+δ of the inter-pip series and the base duration Tb (range from 1.1 to 6s) were varied as independent parameters. The observers had to judge whether the series were accelerating, decelerating, or uniform (3 paradigm), or to distinguish regular from irregular sequences (2 paradigm). "Intervals of subjective uniformity" (isus) were obtained by fitting Gaussian psychometric functions to individual subjects' responses. Progression towards longer base durations (Tb=4.4 or 6s) shifts the isus towards negative δs, i.e., accelerating series. This finding is compatible with the phenomenon of "subjective shortening" of past temporal intervals, which is naturally accounted for by the lossy integration model of internal time representation. The opposite effect observed for short durations (Tb=1.1 or 1.5s) remains unexplained by the lossy integration model, and presents a challenge for further research.

  • Fink, M., Churan, J., & Wittmann, M. (2005). Assessment of auditory temporal-order thresholds - a comparison of different measurement procedures and the influences of age and gender. Restorative Neurology and Neuroscience, 23(5–6), 281–296.

    PURPOSE: The relationship between auditory temporal-order perception and phoneme discrimination has been discussed for several years, based on findings, showing that patients with cerebral damage in the left hemisphere and aphasia, as well as children with specific language impairments, show deficits in temporal-processing and phoneme discrimination. Over the last years several temporal-order measurement procedures and training batteries have been developed. However, there exists no standard diagnostic tool for adults that could be applied to patients with aphasia. Therefore, our study aimed at identifying a feasible, reliable and efficient measurement procedure to test for auditory-temporal processing in healthy young and elderly adults, which in a further step can be applied to patients with aphasia. METHODS: The tasks varied according to adaptive procedures (staircase vs. maximum-likelihood), stimuli (tones vs. clicks) and stimulation modes (binaural- vs. alternating monaural) respectively. A phoneme-discrimination task was also employed to assess the relationship between temporal and language processing. RESULTS: The results show that auditory temporal-order thresholds are stimulus dependent, age related, and influenced by gender. Furthermore, the cited relationship between temporal-order threshold and phoneme discrimination can only be confirmed for measurements with pairs of tones. CONCLUSION: Our results indicate, that different norms have to be established for different gender and age groups. Furthermore, temporal-order measurements with tones seem to be more suitable for clinical intervention studies than measurements with clicks, as they show higher re-test reliabilities, and only for measurements with tones an association with phoneme-discrimination abilities was found.

  • Fink, M., Churan, J., & Wittmann, M. (2006). Temporal processing and context dependency of phoneme discrimination in patients with aphasia. Brain and Language, 98(1), 1–11. https://doi.org/10.1016/j.bandl.2005.12.005

    Standard diagnostic procedures for assessing temporal-processing abilities of adult patients with aphasia have so far not been developed. In our study, temporal-order measurements were conducted using two different experimental procedures to identify a suitable measure for clinical studies. Additionally, phoneme-discrimination abilities were tested on the word, as well as on the sentence level, as a relationship between temporal processing and phoneme-discrimination abilities is assumed. Patients with aphasia displayed significantly higher temporal-order thresholds than control subjects. The detection of an association between temporal processing and speech processing, however, depended on the stimuli and the phoneme-discrimination tasks used. Our results also suggest top-down feedback on phonemic processing.

  • Wittmann, M., Burtscher, A., Fries, W., & von Steinbüchel, N. (2004). Effects of brain-lesion size and location on temporal-order judgment. Neuroreport, 15(15), 2401–2405. https://doi.org/10.1097/00001756-200410250-00020

    We assessed the effect of size and localization of a brain lesion on patients' abilities to perceive the temporal order of two acoustic stimuli. In those patients who had performed with impaired order thresholds, local overlaps of lesions as analyzed with CT were found in specific left-hemispheric regions of the temporal and parietal lobe. However, a moderate association of lesion size and temporal-order threshold was found among all brain-injured patients (n = 30), a correlation that was most pronounced in patients with right-hemispheric lesions. This non-specific effect of lesion size has to be discussed critically with respect to behavioral findings of an association between temporal-processing abilities and language competence.

  • Berwanger, D., Wittmann, M., von Steinbüchel, N., & von Suchodoletz, W. (2004). Measurement of temporal-order judgment in children. Acta Neurobiologiae Experimentalis, 64(3), 387–394. https://doi.org/10.55782/ane-2004-1521

    Abnormal auditory temporal processing might be an underlying deficit in language disabilities. The auditory temporal-order threshold, one measure for temporal processing abilities, is defined as the shortest time interval between two acoustic events necessary for a person to be able to identify the correct temporal order. In our study, we examined the reliability of the auditory temporal-order threshold during a one-week period and over a time interval of four months in normally developing children aged 5 to 11 years. The results of our method show that children younger than 7 years have difficulties performing the task successfully. The reliability of the assessment of the temporal-order threshold during a period of one week is only moderate, and its stability over a time interval of four months is low. The results show that auditory-order thresholds in children have to be treated with caution. A high temporal-order threshold does not necessarily predict disabilities in temporal processing.

  • Wernery, J., Atmanspacher, H., Kornmeier, J., Candia, V., Folkers, G., & Wittmann, M. (2015). Temporal Processing in Bistable Perception of the Necker Cube. Perception, 44(2), 157–168. https://doi.org/10.1068/p7780

    Perception of ambiguous figures is unstable and alternates repeatedly between possible interpretations. Some approaches to explaining this phenomenon have, so far, assumed low-level bottom-up mechanisms like adaptation and mutual inhibition of underlying neural assemblies. In contrast, less precise top-down approaches assume high-level attentional control mechanisms generalised across sensory modalities. In the current work we focused on specific aspects of the top-down approach. In a first study we used dwell times (periods of transiently stable percepts) and the parameters of dwell time distribution functions to compare the dynamics of perceptual alternations between visual (Necker cube) and auditory ambiguity (verbal transformation effect). In a second study we compared the endogenous alternation dynamics of the Necker cube with parameters from two attention tasks with different regimes of temporal dynamics. The first attention task (d2) is characterised by endogenous self-paced dynamics, similar to the dynamics underlying perceptual alternations of ambiguous figures, and we found clear correlations between dwell time parameters (Necker cube) and processing speed (d2 task). The temporal dynamics of the second (go/no-go) attention task, in contrast, are exogenously governed by the stimulus protocol, and we found no statistically significant correlation with the Necker cube data. Our results indicate that both perceptual instability and higher-level attentional tasks are linked to endogenous brain dynamics on a global coordinating level beyond sensory modalities.

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