Profiles

Mats E. Nilsson

Mats Nilsson

Professor

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Arbetar vid Psykologiska institutionen
Telefon 08-16 46 05
E-post mnn@psychology.su.se
Besöksadress Frescati hagväg 9A
Rum 205
Postadress Psykologiska institutionen 106 91 Stockholm

Forskning

My research interests

  • Psychoacoustics
  • Auditory learning and expertise
  • Effects of environmental sounds on health and well-being
  • Research methods for the behavioral sciences

Publications on Google Scholar

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Publikationer

I urval från Stockholms universitets publikationsdatabas
  • 2016. Mats E. Nilsson, Bo N. Schenkman. Hearing Research 332, 223-232

    Blind people use auditory information to locate sound sources and sound-reflecting objects (echolocation). Sound source localization benefits from the hearing system's ability to suppress distracting sound reflections, whereas echolocation would benefit from “unsuppressing” these reflections. To clarify how these potentially conflicting aspects of spatial hearing interact in blind versus sighted listeners, we measured discrimination thresholds for two binaural location cues: inter-aural level differences (ILDs) and inter-aural time differences (ITDs). The ILDs or ITDs were present in single clicks, in the leading component of click pairs, or in the lagging component of click pairs, exploiting processes related to both sound source localization and echolocation. We tested 23 blind (mean age = 54 y), 23 sighted-age-matched (mean age = 54 y), and 42 sighted-young (mean age = 26 y) listeners. The results suggested greater ILD sensitivity for blind than for sighted listeners. The blind group's superiority was particularly evident for ILD-lag-click discrimination, suggesting not only enhanced ILD sensitivity in general but also increased ability to unsuppress lagging clicks. This may be related to the blind person's experience of localizing reflected sounds, for which ILDs may be more efficient than ITDs. On the ITD-discrimination tasks, the blind listeners performed better than the sighted age-matched listeners, but not better than the sighted young listeners. ITD sensitivity declines with age, and the equal performance of the blind listeners compared to a group of substantially younger listeners is consistent with the notion that blind people's experience may offset age-related decline in ITD sensitivity.

  • 2016. Anders Sand, Mats E. Nilsson. Consciousness and Cognition 44, 29-40

    A difficulty for reports of subliminal priming is demonstrating that participants who actually perceived the prime are not driving the priming effects. There are two conventional methods for testing this. One is to test whether a direct measure of stimulus perception is not significantly above chance on a group level. The other is to use regression to test if an indirect measure of stimulus processing is significantly above zero when the direct measure is at chance. Here we simulated samples in which we assumed that only participants who perceived the primes were primed by it. Conventional analyses applied to these samples had a very large error rate of falsely supporting subliminal priming. Calculating a Bayes factor for the samples very seldom falsely supported subliminal priming. We conclude that conventional tests are not reliable diagnostics of subliminal priming. Instead, we recommend that experimenters calculate a Bayes factor when investigating subliminal priming.

  • 2018. Mats E. Nilsson. Journal of the Acoustical Society of America 143 (6), EL456-EL462

    Many blind people learn to use sound reflections to localize objects. However, precedence-effect research has reported evidence both for and against the possibility to improve lateralization of lag clicks preceded by lead clicks. This training study used stimuli more relevant to human echolocation than did previous training studies. One participant, the author, practiced lateralizing a lag-click inter-aural level difference (ILD) of 10 dB for 60 days, with performance measured in the lag-lead peak amplitude ratio at threshold. Clear improvements were observed at interclick intervals of 2-18 ms, suggesting that extracting a large lag-click ILD may improve with practice.

  • 2017. Stefan Wiens, Mats E. Nilsson. Educational and Psychological Measurement 77 (4), 690-715

    Because of the continuing debates about statistics, many researchers may feel confused about how to analyze and interpret data. Current guidelines in psychology advocate the use of effect sizes and confidence intervals (CIs). However, researchers may be unsure about how to extract effect sizes from factorial designs. Contrast analysis is helpful because it can be used to test specific questions of central interest in studies with factorial designs. It weighs several means and combines them into one or two sets that can be tested with t tests. The effect size produced by a contrast analysis is simply the difference between means. The CI of the effect size informs directly about direction, hypothesis exclusion, and the relevance of the effects of interest. However, any interpretation in terms of precision or likelihood requires the use of likelihood intervals or credible intervals (Bayesian). These various intervals and even a Bayesian t test can be obtained easily with free software. This tutorial reviews these methods to guide researchers in answering the following questions: When I analyze mean differences in factorial designs, where can I find the effects of central interest, and what can I learn about their effect sizes?

  • 2017. Anders Sand, Mats E. Nilsson. Psychological Science 28 (3), 346-355

    Is semantic priming driven by the objective or perceived meaning of the priming stimulus? This question is relevant given that many studies suggest that the objective meaning of invisible stimuli can influence cognitive processes and behavior. In an experiment involving 66 participants, we tested how the perceived meaning of misperceived stimuli influenced response times. Stroop priming (i.e., longer response times for incongruent than for congruent prime-target pairs) was observed in trials in which the prime was correctly identified. However, reversed Stroop priming was observed when the prime stimulus was incorrectly identified. Even in trials in which participants reported no perception of the prime and identified the primes at close to chance level (i.e., trials that meet both subjective and objective definitions of being subliminal), Stroop priming corresponded to perceived congruency, not objective congruency. This result suggests that occasional weak percepts and mispercepts are intermixed with no percepts in conditions traditionally claimed to be subliminal, casting doubt on claims of subliminal priming made in previous reports.

Visa alla publikationer av Mats Nilsson vid Stockholms universitet

Senast uppdaterad: 25 februari 2019

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