Markus Ostarek

Publications

Displaying 1 - 5 of 5
  • Kochari, A. R., & Ostarek, M. (2018). Introducing a replication-first rule for PhD projects (commmentary on Zwaan et al., ‘Making replication mainstream’). Behavioral and Brain Sciences, 41: e138. doi:10.1017/S0140525X18000730.

    Abstract

    Zwaan et al. mention that young researchers should conduct replications as a small part of their portfolio. We extend this proposal and suggest that conducting and reporting replications should become an integral part of PhD projects and be taken into account in their assessment. We discuss how this would help not only scientific advancement, but also PhD candidates’ careers.
  • Ostarek, M. (2018). Envisioning language: An exploration of perceptual processes in language comprehension. PhD Thesis, Radboud University Nijmegen, Nijmegen.
  • Ostarek, M., Ishag, I., Joosen, D., & Huettig, F. (2018). Saccade trajectories reveal dynamic interactions of semantic and spatial information during the processing of implicitly spatial words. Journal of Experimental Psychology: Learning, Memory, and Cognition, 44(10), 1658-1670. doi:10.1037/xlm0000536.

    Abstract

    Implicit up/down words, such as bird and foot, systematically influence performance on visual tasks involving immediately following targets in compatible vs. incompatible locations. Recent studies have observed that the semantic relation between prime words and target pictures can strongly influence the size and even the direction of the effect: Semantically related targets are processed faster in congruent vs. incongruent locations (location-specific priming), whereas unrelated targets are processed slower in congruent locations. Here, we used eye-tracking to investigate the moment-to-moment processes underlying this pattern. Our reaction time results for related targets replicated the location-specific priming effect and showed a trend towards interference for unrelated targets. We then used growth curve analysis to test how up/down words and their match vs. mismatch with immediately following targets in terms of semantics and vertical location influences concurrent saccadic eye movements. There was a strong main effect of spatial association on linear growth with up words biasing changes in y-coordinates over time upwards relative to down words (and vice versa). Similar to the RT data, this effect was strongest for semantically related targets and reversed for unrelated targets. Intriguingly, all conditions showed a bias in the congruent direction in the initial stage of the saccade. Then, at around halfway into the saccade the effect kept increasing in the semantically related condition, and reversed in the unrelated condition. These results suggest that online processing of up/down words triggers direction-specific oculomotor processes that are dynamically modulated by the semantic relation between prime words and targets.
  • Popov, V., Ostarek, M., & Tenison, C. (2018). Practices and pitfalls in inferring neural representations. NeuroImage, 174, 340-351. doi:10.1016/j.neuroimage.2018.03.041.

    Abstract

    A key challenge for cognitive neuroscience is deciphering the representational schemes of the brain. Stimulus-feature-based encoding models are becoming increasingly popular for inferring the dimensions of neural representational spaces from stimulus-feature spaces. We argue that such inferences are not always valid because successful prediction can occur even if the two representational spaces use different, but correlated, representational schemes. We support this claim with three simulations in which we achieved high prediction accuracy despite systematic differences in the geometries and dimensions of the underlying representations. Detailed analysis of the encoding models' predictions showed systematic deviations from ground-truth, indicating that high prediction accuracy is insufficient for making representational inferences. This fallacy applies to the prediction of actual neural patterns from stimulus-feature spaces and we urge caution in inferring the nature of the neural code from such methods. We discuss ways to overcome these inferential limitations, including model comparison, absolute model performance, visualization techniques and attentional modulation.
  • Evans, S., McGettigan, C., Agnew, Z., Rosen, S., Cesar, L., Boebinger, D., Ostarek, M., Chen, S. H., Richards, A., Meekins, S., & Scott, S. K. (2014). The neural basis of informational and energetic masking effects in the perception and production of speech [abstract]. The Journal of the Acoustical Society of America, 136(4), 2243. doi:10.1121/1.4900096.

    Abstract

    When we have spoken conversations, it is usually in the context of competing sounds within our environment. Speech can be masked by many different kinds of sounds, for example, machinery noise and the speech of others, and these different sounds place differing demands on cognitive resources. In this talk, I will present data from a series of functional magnetic resonance imaging (fMRI) studies in which the informational properties of background sounds have been manipulated to make them more or less similar to speech. I will demonstrate the neural effects associated with speaking over and listening to these sounds, and demonstrate how in perception these effects are modulated by the age of the listener. The results will be interpreted within a framework of auditory processing developed from primate neurophysiology and human functional imaging work (Rauschecker and Scott 2009).

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