About

Mark Stellmack is an Assistant Teaching Professor in the Department of Psychology at the University of Minnesota. He holds a Ph.D. in Experimental Psychology from Loyola University of Chicago, earned in 1992. His educational background and professional role indicate a focus on psychology, with involvement in teaching courses such as Introduction to Research Methods, Psychology of Hearing, and Introduction to Psychology. His work is based at the College of Liberal Arts, and he is engaged in teaching and research within the field of psychology.

Research topics

• Acoustics
• Mathematics
• Audiology
• Psychology
• Computer science

Selected publications

• Comparison among four psychophysical procedures used to assess sound localization

  The Journal of the Acoustical Society of America · 2026-05-01

  article1st authorCorresponding

  To determine whether listeners use similar cues in absolute judgments and discrimination of sound locations, data were collected in four tasks used to assess sound-localization ability: a pointing task and three discrimination tasks (single interval, cued single interval, and two-alternative forced choice). Four stimuli were used: broadband noise, scrambled-spectrum noise (noise with levels jittered +/–20 dB in 1/3-octave bands), frozen scrambled-spectrum noise (stimuli with the scrambled noise spectrum fixed across intervals of the two-interval tasks), and a 750-Hz pure tone. Performance was better (higher d') in the discrimination tasks relative to the pointing task. However, performance in the pointing task was brought into better alignment with that of the discrimination tasks through an analysis that estimated and removed slowly fluctuating bias from the pointer responses. Discrimination performance was better for the broadband noise and frozen scrambled-spectrum noise than for the scrambled-spectrum noise and pure tone, indicating the influence of spectral cues in the former two. The results suggest that both localization (as in the present pointing task) and source-location discrimination may be based on the perceived locations of stimuli, but that spectral cues that are not associated with perceived location may influence responses for certain types of stimuli.

  PublisherDOI

• Comparison among four psychophysical procedures used to assess sound localizationa).

  PubMed · 2026-05-01

  article1st authorCorresponding

  To determine whether listeners use similar cues in absolute judgments and discrimination of sound locations, data were collected in four tasks used to assess sound-localization ability: a pointing task and three discrimination tasks (single interval, cued single interval, and two-alternative forced choice). Four stimuli were used: broadband noise, scrambled-spectrum noise (noise with levels jittered +/-20 dB in 1/3-octave bands), frozen scrambled-spectrum noise (stimuli with the scrambled noise spectrum fixed across intervals of the two-interval tasks), and a 750-Hz pure tone. Performance was better (higher d') in the discrimination tasks relative to the pointing task. However, performance in the pointing task was brought into better alignment with that of the discrimination tasks through an analysis that estimated and removed slowly fluctuating bias from the pointer responses. Discrimination performance was better for the broadband noise and frozen scrambled-spectrum noise than for the scrambled-spectrum noise and pure tone, indicating the influence of spectral cues in the former two. The results suggest that both localization (as in the present pointing task) and source-location discrimination may be based on the perceived locations of stimuli, but that spectral cues that are not associated with perceived location may influence responses for certain types of stimuli.

  PublisherDOI

• Localization of real and tangent-law panned phantom sound sources in the frontal horizontal plane

  The Journal of the Acoustical Society of America · 2024-03-01 · 1 citations

  article1st authorCorresponding

  Auditory source separations of as little as 1 degree are detectable. However, presenting auditory stimuli at small separations presents technical challenges, with loudspeaker separation limited by transducer diameter. An alternative procedure is to utilize phantom sources, with the perceived position of a single source determined by the relative output levels of two spatially separated loudspeakers. Therefore, it is important to determine whether real and phantom sources can be localized with the same precision. In the present experiment, listeners localized real (individual) sources and phantom sources computed using a tangent-law model giving the same nominal azimuthal angles as the real sources. Listeners used a laser pointer to indicate perceived source location. Infrared cameras detected pointer position with responses stored in terms of azimuth. Signals were broadband or narrowband (300-700 Hz and 3800–4200 Hz) noise, 100 or 500 ms in duration. Generally, phantom sources were localized with less precision than real sources, and high-frequency signals were localized with less precision than broadband or low-frequency signals, with no effect of duration. Results show that phantom sources are localized with sufficient accuracy and precision to be useful in assessing auditory spatial acuity, but they are not localized with the same precision as real sources.

  PublisherDOI

• Horizontal-plane localization of a target in the presence of a distractor: Effect of onset asynchrony

  The Journal of the Acoustical Society of America · 2023-03-01

  article1st authorCorresponding

  Listeners localized a target in isolation and in the presence of a distractor. The target consisted of 10 10-ms Gaussian pulses (energy between 3–5kHz); the distractor was either a 100- or 500-ms narrowband (1–2 kHz) noise burst. The listener, with head unrestrained, was seated in the center of 36 loudspeakers spaced every 10 degrees on the horizontal plane and obscured by screens. On each trial, the target was played through a randomly selected loudspeaker. Listeners used a laser pointer to indicate target location. Pointer position was detected by infrared cameras and the response angle calculated. In separate conditions, distractor position was either fixed or randomized across trials, with target-to-distractor onset synchrony an additional parameter. The left-right component of responses was essentially unaffected by the presence of the distractor in any condition. With notable inter-subject variability, the front-back response component also showed little effect of the distractor. This absence of consistent effect of the distractor contrasts with previously reported work. The target and distractor in the present research, however, were generally more discriminable than in past studies, which likely mitigated at least some of the deleterious effect of the distractor on target localization ability.

  PublisherDOI

• Detecting the hot hand in amateur bowlers

  International Journal of Sport and Exercise Psychology · 2023-10-10 · 2 citations

  article1st authorCorresponding

  ABSTRACTThe hot hand, often invoked in describing athletic performances, refers to the notion that the probability of success is conditional upon recent success or failure. The present paper describes a method of identifying hot-hand behavior in which data from amateur 10-pin bowlers were fit with a model containing dynamically varying probabilities of success and failure (hot-hand model) and one with fixed probabilities (stable model). Full-season data of 27 out of 40 bowlers were found to be better fit by the hot-hand model. Following success, different bowlers showed increased or decreased probability of success (hot-hand behavior or underperformance, respectively). Analysis of the two halves of each bowler's data indicated that the extent of hot-hand behavior or underperformance varied across the season. Overall, results suggest that the conditional probabilities that define performance can vary in an individual over time such that anticipation of hot-hand performance can be a reasonable expectation in certain circumstances.KEYWORDS: Hot handstreaksbowlingprobabilistic modelling AcknowledgmentsThe authors thank Flaherty's Arden Bowl in Arden Hills, Minnesota for providing the data used in these analyses.Disclosure statementNo potential conflict of interest was reported by the author(s).Data availability statementThe data that support the findings of this study are available from the corresponding author, MAS, upon reasonable request.

  PublisherDOI

• Discrimination of interaural intensity differences and monaural intensity increments

  The Journal of the Acoustical Society of America · 2020-10-01

  article1st authorCorresponding

  This study assessed the equivalence of a binaural task (two-interval discrimination of interaural intensity differences, IIDs) and a monaural two-interval increment-discrimination task, in which each interval consisted of two noise bursts of different intensities, with listeners identifying the interval with the larger intensity change. Stimuli were broadband noise, with trial-by-trial feedback provided. An overall level rove between intervals forced listeners to compare the two signals within each interval (across ears in the binaural task and across bursts in the monaural task). Both tasks involved presentation of four signals of different intensities, yielding the same optimal decision statistic. Assuming (1) discrimination of IIDs across intervals amounts to discrimination of lateral position and (2) variability in lateral position increases with IID leads to a prediction of Weber's law. Functions relating threshold IID delta (or monaural increment delta) in dB to the standard IID (or increment) in dB had nearly equal slopes in binaural (0.054) and monaural (0.058) conditions. While the derived binaural decision statistic is based on discrimination of an emergent percept of the stimulus (intracranial position), the similarity of results suggests that monaural increment-discrimination may be based on discrimination of a similarly emergent percept (a loudness step). [Work supported by NIH R01DC00683.]

  PublisherDOI

• Improving Attentiveness: Effect of Cognitive Training on Sustained Attention Measures

  Professional safety · 2019-04-01 · 2 citations

  article
  Publisher

• Format of Instructor Feedback on Student Writing Assignments Affects Feedback Quality and Student Performance

  Teaching of Psychology · 2018-12-03 · 13 citations

  articleOpen access

  Electronic feedback given via word-processing software (e.g., track changes in Microsoft Word) allows for a simple way to provide feedback to students during the drafting process. Research has mostly focused on student attitudes toward electronic feedback, with little investigation of how feedback format might affect the quality of instructor comments. In this study, we experimentally manipulated the feedback format, either electronic or handwritten, used by instructors grading papers in an introductory research methods course. Among the effects observed, instructors using electronic feedback provided longer comments, were less likely to rewrite student passages and were more likely to offer general observations about the writing. Students whose papers were graded using electronic feedback also showed greater improvement on subsequent drafts.

  PublisherOA PDFDOI

• The Effect of Online Cognitive Training on Sustained Attention Measures for Electric Power Line Installers

  SSRN Electronic Journal · 2015-01-01 · 2 citations

  articleOpen access
  PublisherDOI

• Incentivizing Multiple Revisions Improves Student Writing Without Increasing Instructor Workload

  Teaching of Psychology · 2015-09-02 · 4 citations

  article1st authorCorresponding

  Previous research has shown that when students are required to submit a draft and a revision of their writing, large proportions of students do not improve across drafts. We implemented a writing assignment in which students were permitted to submit up to four optional drafts. To encourage substantive revisions, students were awarded additional points if they received all points on the grading rubric. Based on the grades of the instructors, 31% of students eventually earned perfect scores in this assignment, compared to 13% in a typical single revision assignment. Permitting students to submit up to four optional drafts resulted in nearly the same amount of grading for the instructor as requiring students to submit two drafts.

  PublisherDOI

Recent grants

• NIH Grant R03DC005343

  NIH · $220k · 2005

Frequent coauthors

• Neal F. Viemeister

  University of Minnesota

  30 shared

• Raymond H. Dye

  Loyola University Chicago

  25 shared

• Andrew J. Byrne

  Trinity College Dublin

  23 shared

• Andrew J. Niemiec

  Kenyon College

  9 shared

• Stanley Sheft

  Rush University

  7 shared

• Robert A. Lutfi

  University of South Florida

  6 shared

• Yasmine L. Konheim‐Kalkstein

  6 shared

• William A. Yost

  4 shared