Research group · CNS
Perception & Decision Lab
Uncovering the neural and computational mechanisms by which sensory evidence is integrated, weighted, and translated into perceptual judgements and decisions.
Overview
The Perception & Decision Lab combines psychophysics, neuroimaging, and normative modelling to understand how human and animal observers solve the fundamental problem of acting under uncertainty. The group treats perception and decision as two phases of a single inference process: the brain forms probabilistic beliefs about the world from noisy sensory data, then commits to an action according to an (approximately) optimal policy that trades speed against accuracy.
Experimental work in the lab uses carefully controlled psychophysical paradigms — including multi-cue integration, time-pressure tasks, and perceptual learning protocols — combined with EEG, high-density MEG, and fMRI to track neural correlates of evidence accumulation and confidence. Modelling work employs drift-diffusion models, Bayesian observer models, and more recently, recurrent neural networks as normative benchmarks.
The lab collaborates with the Computational Neuroscience Group on mechanistic network models and with the Neural Engineering Group on brain-computer interface protocols that exploit perceptual decision signatures. External partnerships include clinical neuropsychology groups studying decision impairments in psychiatric disorders.
Research themes
- Bayesian and signal-detection models of multi-sensory cue integration
- Neural correlates of evidence accumulation and decision commitment in EEG/MEG
- Metacognition: representations of confidence and uncertainty in prefrontal cortex
- Speed-accuracy tradeoffs and urgency signals in time-pressured decisions
- Perceptual learning: how practice reshapes neural representations and decision criteria
- Cross-modal attention and its modulation of perceptual sensitivity
Current projects
Active research programmes, 2024–2027
Project · VX-PDL-01
AccumMEG: Tracking Evidence Accumulation in Human MEG
Recording whole-brain MEG at 1 kHz sampling during a continuous motion-discrimination task to identify the spatial and temporal signatures of evidence accumulation. Aims to localise the decision variable to specific fronto-parietal sources and measure its temporal dynamics with millisecond precision.
Funding: VIAS Research Excellence Grant · 490,000 cr
Project · VX-PDL-02
MetaConf: Neural Basis of Perceptual Confidence
Using high-density EEG and pupillometry to track trial-by-trial confidence reports during tactile and auditory detection tasks. Developing a hierarchical drift-diffusion model that generates both primary decisions and confidence ratings from a single latent accumulator.
Funding: External partner grant VX-META-23 · 355,000 cr
Project · VX-PDL-03
CrossModal: Audiovisual Cue Integration under Conflict
Testing the maximum-likelihood estimation model of multisensory integration against human observers exposed to spatially and temporally misaligned audiovisual stimuli. Examines how the brain resolves causal uncertainty — whether two signals come from the same source — and how this is modulated by training.
Funding: VIAS Graduate School Fellowship · 108,000 cr
Selected publications
- Steiner R., Arango M., Küppers I. "Fronto-parietal MEG sources encode a leaky accumulator during vibrotactile discrimination." VIAS Journal of Cognitive Neuroscience 15(2), 2024. DOI: 10.veyra/VX-4453
- Steiner R., Benedetti O. "Confidence reports reflect a post-decisional read-out of accumulated evidence in a hierarchical DDM." Veyra Neural Dynamics 5(1), 2023. DOI: 10.veyra/VX-4219
- Küppers I., Steiner R. "Urgency signals in LFP power spectra anticipate motor commitment by 120 ms." VIAS Neuroscience Reports 9, 2022. DOI: 10.veyra/VX-4031
- Arango M., Steiner R., Okoro H. "Shared subspaces for perceptual confidence and accuracy in frontal cortex: a joint model." Veyra Computational Neuroscience 7(4), 2022. DOI: 10.veyra/VX-3866
- Benedetti O., Steiner R. "Causal inference explains the ventriloquist effect and its afterimage in human psychophysics." VIAS Multisensory Research 3(2), 2021. DOI: 10.veyra/VX-3638
- Steiner R. "A Bayesian observer model for perceptual learning in frequency discrimination." Veyra Psychophysics 1(1), 2019. DOI: 10.veyra/VX-3201
People
Group lead: Dr. Roald Steiner · View all Veyra people
Postdoctoral researchers: Dr. Marcelina Arango, Dr. Olga Benedetti, Dr. Ingo Küppers.
PhD students: Tariq Elshafei, Jana Brixova, Wioletta Ptak, Selin Yıldız, Dominic Nyström, Fiona Callahan, Quentin Barraud.
Research staff: Dr. Eszter Farkas (EEG/MEG engineer), Vera Koss (psychophysics technician), Bastian Rudolph (data analyst).