I am a multisensory perception scientist working across fundamental and applied research. I investigate how the senses interact to generate a coherent representation of our bodies and the environment, and how this information guides action. My research combines psychophysics with ideal observer and stimulus-computable models of multisensory perception and action.

A central strand of this work is the Multisensory Correlation Detector, a biologically inspired model that predicts audiovisual perception directly from sensory input. This research aims to explain the computations linking sensory signals to perceptual experience, behaviour and neural responses.

I apply this understanding to the development of immersive technologies and sensory augmentation. Previously, I worked as a research scientist and principal investigator at Meta Reality Labs, investigating haptics, multisensory integration and spatial audio for virtual and augmented reality. I work with hardware and software engineers on interface design, algorithm development and quantitative perceptual evaluation.

My applied projects include algorithms that localise sound sources in video and generate spatial audio for films with non-spatial soundtracks. I have also developed SonicWhiskers, a sensory substitution system that converts optical input into auditory and haptic feedback. The aim is to help blind and partially sighted people access information about their surroundings and to extend perception when vision is unavailable.

I welcome enquiries about research collaborations and applied projects, including perceptual evaluation, computational modelling and interface development.

Education

DPhil in Experimental Psychology
University of Oxford

Laurea in Psychology
University of Milano-Bicocca

Editorial roles

Associate Editor for

  • ACM Transactions on Applied Perception
  • Multisensory Research
  • Frontiers in Human Neuroscience

Selected awards

2014 · Attempto Prize
University of Tübingen — for research on natural auditory scene statistics and spatial hearing.

2013 · National Award for Best PhD Thesis
Italian Association of Psychology (AIP) Experimental Psychology Section

Perception Scientist Applied Perception Multisensory Integration Vision, Audition & Haptics

Research

My research investigates how the brain processes and combines information from vision, hearing and touch to perceive our bodies and surroundings and guide action. I combine psychophysics, computational modelling and neuroscience to understand the principles of sensory perception, with applications in immersive technologies and sensory augmentation.

Multisensory Correlation Detector model
Multisensory Correlation Detector (MCD), a biologically inspired model for multisensory integration. Parise & Ernst (2016), Nature Communications.

Multisensory integration

All animals, even the simplest ones, rely on multiple sensory systems to perceive their bodies and surroundings. My research investigates the computational principles governing multisensory integration, with particular emphasis on vision and audition.

A central question is how the brain determines which sensory signals originate from a common source and should therefore be integrated. I address this question through psychophysics and stimulus-computable models, with applications ranging from sensory substitution to artificial perception and augmented reality.

Selected publications

  • Parise, Parise & Parise (2026). Perceiving audiovisual synchrony: A quantitative synthesis of simultaneity and temporal order judgments from 185 studies. Neuroscience & Biobehavioral Reviews.
  • Parise (2025). Correlation detection as a stimulus computable account for audiovisual perception, causal inference, and saliency maps in mammals. eLife.
  • Parise & Ernst (2025). Multisensory integration operates on correlated input from unimodal transient channels. eLife.
  • Pesnot Lerousseau et al. (2022). Multisensory correlation computations in the human brain identified by a time-resolved encoding model. Nature Communications.
  • Parise & Ernst (2017). Noise, multisensory integration, and previous response in perceptual disambiguation. PLOS Computational Biology.
  • Parise & Ernst (2016). Correlation detection as a general mechanism for multisensory integration. Nature Communications.
  • Parise, Spence & Ernst (2012). When correlation implies causation in multisensory integration. Current Biology.
Frequency-dependent sound localisation responses
Frequency-induced biases in sound-source localisation, illustrated by localisation responses across different frequency bands. Parise, Knorre & Ernst (2014), PNAS.

Spatial hearing

Unlike vision and touch, which rely on spatially organised sensory receptors, the cochlea is organised primarily according to sound frequency. Nevertheless, humans can accurately localise sounds in their surroundings.

My research investigates the computational principles of spatial hearing, including how acoustic cues and natural scene statistics shape sound localisation, how we perceive auditory motion, and how perceptual learning allows us to adapt to unfamiliar acoustic environments.

Selected publications

Pseudo-haptic weight perception in virtual reality
Pseudo-haptic weight: manipulating the control-display ratio changes the perceived weight of virtual objects without physical force feedback. Samad et al. (2019), ACM CHI.

Touch and motor control

Our hands are our primary means of interacting with the environment. Touch and proprioception provide information about objects and our own movements, contributing to both perception and action.

My research investigates how tactile information contributes to manual interactions and how multisensory integration can compensate for impoverished haptic feedback. A particular focus is the development and evaluation of perceptually informed interfaces for virtual and augmented reality.

Selected publications

From sensory signals to perception

Multisensory Correlation Detector model

A biologically inspired model that turns images and sounds into predictions of what we perceive—and where we look.

One mechanism. Many perceptual effects.

When someone speaks, their movements and voice change together. The Multisensory Correlation Detector (MCD) uses this shared structure to connect information across the senses.

Rather than starting with a description of a stimulus, the model processes the stimulus itself. From pixels and audio samples, it generates predictions about audiovisual timing, cue integration, perceptual illusions and attention. [1]

Watch: predicting where people look
The recorded conversation is shown above the model’s correlation map; coloured markers show measured gaze. The model highlights the active speaker without face recognition or speech recognition. Demonstration accompanying Parise (2025), using footage and eye-tracking data from Coutrot & Guyader (2015).
69experiments simulated
3 specieshumans, rats and monkeys
>0.97reported mean model–data correlation

Results reported in the 2025 population-model paper. Correlation measures agreement with the data, not percentage accuracy. The model shares its sensory architecture across tests; task-specific parameters and species-specific temporal tuning are described below. [1]

The gap

What perception achieves is not yet how it works

Multisensory research has been strongly shaped by ideal-observer models, particularly maximum-likelihood estimation and Bayesian causal inference. In David Marr’s terms, these are primarily computational-level accounts: they explain the goals of perception, such as obtaining reliable estimates and deciding which signals belong together.

Their success leaves an important question open. How are these computations performed on the sensory stream? The influential cue-integration models typically begin with quantities such as location, reliability or audiovisual delay. Biological systems must first extract useful information from changing light and sound.

The MCD addresses this algorithmic gap by making the intermediate representations and transformations explicit. It does not reject the achievements of Bayesian models: it asks how behaviour consistent with those accounts can emerge from elementary operations on sensory signals. [1]

  1. 01Images & soundsThe sensory input
  2. 02Detect changesTransient sensory responses
  3. 03Compare the sensesCorrelation and relative lag
  4. 04Read out the responsePerceptual decisions or saliency

Statistical optimality

MLE and Bayesian causal inference explain a lot — but they start later in the computation

Maximum-likelihood estimation (MLE) explains why two sensory cues are often combined in proportion to their reliability. Bayesian causal inference (BCI) explains why that integration weakens or breaks down when the cues are too discrepant, by weighting fusion against the probability that the signals arise from a common cause.

These frameworks are central to modern multisensory research and the MCD is meant to complement them, not replace them. Their main limitation is that they typically operate on experimenter-defined variables — such as cue location, audiovisual delay, cue reliability and their probability distributions. Real perceptual systems do not receive those abstractions. They receive patterns of light and sound, and must infer those quantities from the sensory stream.

The MCD works one step earlier. It operates on signals and their processing: images, sounds, and the changing structure they share over time and space. From a scientific perspective, this means that the problem it solves is closer to the one biological perceptual systems actually face. A further consequence is breadth: the same model that reproduces MLE-like cue combination and BCI-like segregation can also be run on realistic audiovisual scenes, such as a real ventriloquist performance, where classical parametric models do not directly operate. [1]

What statistically optimal models usually take as input

  • Estimated cue locations, lags, or intensities
  • Reliability terms and probability distributions
  • A decision about whether to integrate or segregate cues

What the MCD takes as input

  • The actual audiovisual signals: frames, pixels, waveforms and transients
  • Local computations of correlation and relative lag over space and time
  • Read-outs from which MLE-like integration, BCI-like behaviour and saliency can emerge

In the 2025 population-model paper, the spatial population of MCD units reproduces the classic signatures associated with MLE and BCI, while also extending naturally to realistic, dynamic material. This is the bridge between ideal-observer theory and stimulus-computable modelling. [1]

The mechanism

A familiar circuit, a different question

The starting point is the Hassenstein–Reichardt detector, a classic model of motion vision. It compares signals from neighbouring visual locations after delaying one relative to the other. Its component operations have been studied extensively in insect neuroscience, providing a physiologically grounded starting point rather than an arbitrary mathematical construction.

We adapted this principle to compare inputs across senses rather than across neighbouring points in an image. Two complementary outputs indicate how strongly the signals are correlated and which modality leads. Temporal filtering and simple interactions between signals make both outputs evolve continuously over time. [4]

The research programme is a test of sufficiency: how much of multisensory perception can this minimal, biologically plausible mechanism explain? The aim is not a separate model for every illusion, but a shared processing architecture tested against different stimuli, tasks and measures.

A single detector compares auditory and visual transients and produces correlation and lag signals. A spatial population repeats this operation, with normalisation supporting a combined location estimate.
From a local computation to a population. Left: a detector provides correlation and lag read-outs. Right: spatially arranged detectors combine input from auditory and visual transient channels; normalisation supports a population estimate of location. Original artwork from Parise (2026), Figure 1. [7]
Watch the original detector in action
The original MCD’s two outputs change as the relative timing of the inputs changes. Correlation is strongest near alignment; the lag signal distinguishes which sense leads. This silent animation accompanies Parise & Ernst (2016); later work refined the input stage to detect unsigned transients. [4]

The research programme

Evidence, not just a plausible circuit

2012–2013

Correlation matters beyond coincidence

Before developing the model, we tested whether the fine temporal structure of audiovisual signals affects integration. In a localisation task, the gain in precision matched the prediction for optimal integration only when the signals were temporally correlated—even though they occupied the same physical location in both conditions. A subsequent study showed the complementary cost: correlated signals made spatial discrepancies harder to detect. Correlation therefore promotes binding, not simply better performance on every task. [2] [3]

Figure from the 2012 Current Biology paper showing correlated and uncorrelated audiovisual stimuli and the localisation set-up used to test whether correlation promotes multisensory integration.
From the 2012 study. Correlated and uncorrelated audiovisual sequences were compared using the same localisation task. This was the empirical starting point for the correlation-based framework. Figure 1 from Parise, Spence & Ernst (2012). [2]

2016

Predicting a percept, not recovering a label

The first MCD was tested with independently generated, random sequences of clicks and flashes. Observers judged whether the streams seemed to share a cause and which seemed to lead. These sequences did not supply a uniquely defined correct classification for the two streams as a whole. Success therefore required matching the stimulus features that shaped human judgements—not merely recovering an experimenter-assigned answer. Given the same sequences, the MCD reproduced the observed classification patterns. [4]

2022

Testing the computations against brain activity

In a magnetoencephalography (MEG) study, participants judged audiovisual sequences while their brain activity was recorded. A time-resolved encoding analysis linked the MCD’s dynamics to temporo-parietal responses. Correlation-related signals were evident across tasks; lag-related evidence was more task-dependent. This connects a model of behavioural judgements to the unfolding neural computations, rather than only to a final response. [6]

Figure from the 2022 MEG study showing spatio-temporal cluster analysis, cluster activity as a function of MCD correlation output, single-trial behavioural prediction, and estimated cortical sources.
The link to brain activity. A simple summary figure from the MEG paper: MCD-related dynamics predict task-relevant neural activity and help localise its cortical sources. Figure 3 from Pesnot Lerousseau et al. (2022). [6]

2025

What enters the detector? Changes, not sustained intensity

Two psychophysical experiments identified the importance of unsigned transients: changes in a signal, regardless of whether its intensity rises or falls. This matters because a shared event need not make light and sound intensities change in the same direction. The relevant evidence can be that something changes in both senses at the same time.

A striking prediction follows. For periodically modulated stimuli, both onsets and offsets provide matching events. Perceived synchrony can therefore peak twice within one stimulus cycle—when the signals are in phase and when they are half a cycle apart. Observers showed this frequency-doubling effect, and the transient-based MCD reproduced it. [5]

Reported synchrony peaks twice per period of audiovisual phase shift. Human data points closely follow the MCD curve; the two ends of the horizontal axis represent the same phase.
Two synchrony peaks, one mechanism. Dots: human judgements. Curve: MCD responses. The endpoints repeat the same phase; the second distinct maximum occurs halfway through the cycle. Cropped from Parise & Ernst (2025), Figure 5d. [5]

The population model

From clicks and flashes to natural audiovisual scenes

A single detector compares two signals over time. A lattice of detectors extends the same operation across space: each unit compares local visual changes with auditory input. With spatialised sound, the sensory inputs have aligned receptive fields; with a mono soundtrack, the auditory envelope is shared across image locations. The architecture does not require lateral message-passing between detector units; a population normalisation is used for spatial estimation.

This makes the model image- and sound-computable. It can process the footage used in an experiment, rather than being supplied only with its nominal audiovisual delay or spatial discrepancy. The 2025 study tested this architecture across 69 experiments, spanning seven behavioural tasks and data from 534 humans, 110 rats and two monkeys. [1]

Time

Synchrony and temporal-order judgements, temporal adaptation, and the dependence of audiovisual speech illusions on timing.

Space

Reliability-weighted cue combination, the ventriloquist effect, and the integration or segregation of signals described by Bayesian causal inference.

Attention

Audiovisual saliency maps that identify correlated regions of a scene and predict the distribution of gaze during natural viewing.

The important result is not just the number of successful fits. The same low-level computations connect effects usually studied in separate paradigms. MLE-like cue integration and BCI-like segregation emerge from a shared sensory mechanism, rather than from independent explanations for each phenomenon. Because the model runs on audiovisual stimuli themselves, the scientific model and a practical device are working on the same kind of representation: real signals in time and space. [1]

What was fitted, and what does the model not claim?

The population study estimated a common set of temporal-filter constants jointly across human timing experiments, with a separate, faster tuning for rats. These constants were then held fixed across additional tests. Depending on the simulation, 0–4 further parameters described task read-out or spatial uncertainty; the gaze analysis required no additional fitted parameters. The model is therefore not wholly parameter-free, and the reported mean correlation is not a held-out accuracy score for every experiment.

The speech simulations explain how audiovisual timing affects integration and the incidence of an illusion, not how a phoneme or word is recognised. The model does not currently include linguistic knowledge or top-down expectations. Its breadth is demonstrated over the tested studies, not over every possible audiovisual phenomenon. [1]

See the computations

Illusions without a specialised illusion mechanism

These demonstrations show the model’s responses to the audiovisual material itself. No face detector, lip tracker or speech recogniser is needed to compute the maps. Play with sound to experience the stimuli; browser playback is illustrative, not a calibrated psychophysical test. [1]

When seeing changes hearing

The McGurk illusion. Mismatched lip movements and speech can change the syllable a listener reports. As audiovisual delay varies, the model’s correlation response changes with the likelihood of integration. The response concentrates around the mouth without recognising it as a mouth. The model predicts the timing dependence of the effect, not phoneme identity. Demonstration accompanying Parise (2025).

When sound follows a visual source

The ventriloquist effect. The upper panel shows the scene; the panels below show the spatial and temporal distribution of correlation. The response follows the visual source whose movements match the soundtrack, including the dummy. It does not need to understand the performance. The dummy’s voice was pitch-shifted in post-production. Demonstration accompanying Parise (2025).
A closer look: the response to natural speech
The video, correlation map and lag map are shown side by side. Traces below show the stimuli, transient responses and detector outputs as the audiovisual delay changes. This makes the intermediate processing visible, not just the final prediction. Demonstration accompanying Parise (2025).

An unexpected test

Synchrony with distance without explicitly calculating distance

Sound takes longer than light to reach an observer. In a classic experiment, Alais & Carlile (2005) found that subjective audiovisual alignment shifted with perceived source distance, approximately as expected from sound propagation. The result was interpreted in terms of estimating distance and compensating for the associated acoustic travel time. [8]

The MCD reproduces this shift without an explicit distance estimate or a stored speed of sound. The explanation lies in the auditory envelope: in the tested reverberant stimuli, increasing distance weakens the direct onset relative to the reverberant tail. The sound becomes less front-loaded, changing the evidence received by the lag detector.

Summary figure showing scaling of audiovisual synchrony with distance: stimulus log envelopes for different distances, temporal-order judgement curves, and the resulting shift in subjective synchrony as distance increases.
Scaling audiovisual synchrony with distance. The 2025 paper shows, side by side, the distance-dependent stimulus envelopes, the psychometric curves, and the resulting shift in subjective synchrony. The key point is that the scaling emerges from changes in the auditory signal itself. [1]

Stimuli

  • Click envelopes recorded at different apparent distances
  • The reverberant tail stays the same
  • The direct onset weakens with distance

Psychometric curves

  • Empirical and predicted synchrony curves are shown for each distance
  • All four curves share the same decision parameters
  • The separation across curves comes from the signal waveform

Scaling result

  • The point of subjective synchrony shifts systematically with distance
  • The shift scales approximately with the speed of sound
  • The MCD reproduces this trend from the stimulus structure alone
In the stimulusDirect onset weakens relative to the reverberant tail
In the detectorThe temporal balance of sensory evidence shifts
In the predictionThe point of subjective alignment shifts

All four distance conditions were fitted with one shared set of decision parameters, while the temporal filters were held fixed. The separation between the curves therefore arose from the stimulus waveforms, not a different delay correction fitted to each distance. [1]

The broader lesson: structure already present in a sensory signal can support behaviour that appears to require an explicit physical calculation.

The 2025 paper shows these three components together: the distance-dependent click envelopes, the corresponding psychometric curves, and the final scaling of subjective synchrony with distance. This demonstrates a sufficient signal-based explanation of the tested effect; it does not imply that the brain never represents distance. See Figure 2B for the full stimuli and plots.

From a scientific model to applied research

Applied perception projects

This section is an invitation to collaborate on applied perception projects. Because the model operates directly on audiovisual signals, it can be used to analyse the same kinds of inputs that devices produce and users experience. Instead of specifying an abstract audiovisual mismatch, we can present the model with the actual content, inspect its intermediate responses, and ask how particular design choices might affect perception.

Perceptual evaluation & immersive interfaces

Use stimulus-specific predictions to investigate audiovisual timing, binding and salience in recordings or prototypes. The model can guide experimental comparisons and help identify which signal features drive a perceptual effect.

Audiovisual localisation & spatial audio

Explore correspondence maps for associating sounds with visible sources. This offers a foundation for bespoke algorithms in audiovisual media, spatial audio and systems that must orient towards relevant events.

Interpretable multimodal AI & robotics

A high response has a concrete explanation: local auditory and visual changes are correlated. Such a module could provide correspondence-based supervision for learning from unlabelled video, or an inspectable sensory front end for a larger system.

These directions follow from the model’s demonstrated ability to process audiovisual signals and generate interpretable correspondence maps. This matters for industry because the model and a practical application operate on the same kind of representation: the images and sounds delivered by devices and encountered by users. Its simple, local operations also motivate investigation of efficient implementations. Improved learning efficiency, real-time device performance and benefits in a particular product remain questions to test, not results established by the existing experiments. [1]

Interested in an applied perception collaboration?

I welcome collaborative R&D, bespoke algorithm development and model-based perceptual evaluation for immersive technologies, audiovisual systems, assistive technologies and multimodal machine perception.

Discuss an applied project

Read further

The research behind the model

[1] Key paper · Cesare V. Parise · eLife, 2025

Correlation detection as a stimulus computable account for audiovisual perception, causal inference, and saliency maps in mammals

The population architecture, the 69-experiment evaluation, natural-scene demonstrations, assumptions and limitations. Full methods and MATLAB source code accompany the article.

Read the paper and access the code
Foundations, experimental tests and perspective
  1. Parise, Spence & Ernst (2012). When correlation implies causation in multisensory integration. Current Biology.The precision benefit of integrating temporally correlated signals.
  2. Parise, Harrar, Ernst & Spence (2013). Cross-correlation between auditory and visual signals promotes multisensory integration. Multisensory Research.The corresponding cost: reduced sensitivity to spatial discrepancies.
  3. Parise & Ernst (2016). Correlation detection as a general mechanism for multisensory integration. Nature Communications.The original detector and behavioural tests with stochastic sequences.
  4. Parise & Ernst (2025). Multisensory integration operates on correlated input from unimodal transient channels. eLife.The transient input stage and the frequency-doubling prediction.
  5. Pesnot Lerousseau, Parise, Ernst & van Wassenhove (2022). Multisensory correlation computations in the human brain identified by a time-resolved encoding model. Nature Communications.The bridge from model dynamics to MEG responses.
  6. Parise (2026). A new look at audiovisual perception: From correlation detection to a general theory of multisensory integration. The Cognitive Psychology Bulletin, issue 11.A narrative overview of the development of the framework.
  7. Alais & Carlile (2005). Synchronizing to real events: Subjective audiovisual alignment scales with perceived auditory depth and speed of sound. Proceedings of the National Academy of Sciences.The distance-and-synchrony experiment reproduced by the MCD.

Publications

Peer-reviewed articles, book chapters, and dissertations.

Full-text copies of my publications are freely available on ResearchGate.

Patents

US patents on perceptual and multisensory technologies.

Impedance shaping for haptic interfaces on wearable devices

US Patent No. 11,385,716 · 2022

Mukherjee, G., Shimasaki, K., King, R., Israr, A., Parise, C., Piazza, D., Samad, M. J., Gatti, E., & Corson, N. R.

View on Google Patents →

Using audio visual correspondence for sound source identification

US Patent No. 11,234,090 · 2022

Donley, J., Robinson, P., & Parise, C.

View on Google Patents →

Audiovisual correspondence based signal augmentation

US Patent No. 11,087,777 · 2021

Parise, C., Brimijoin, O., & Robinson, P.

View on Google Patents →

Methods and systems to control tactile content

US Patent No. 10,970,036 · 2021

Parise, C., Khaleghimeybodi, M., Robinson, P., & Gottlieb, P.

View on Google Patents →

Contact

I welcome opportunities to collaborate on fundamental research and applied projects at the intersection of perception science, neuroscience and technology.

Academic collaborations

I welcome collaborations in multisensory perception, psychophysics and computational neuroscience, as well as invitations for seminars, research visits and interdisciplinary projects.

Prospective PhD students and postdoctoral researchers are also encouraged to get in touch to discuss potential projects, supervision and funding opportunities.

Industry & applied research

I work with industry partners on perceptual evaluation, computational modelling and interface development, particularly in immersive technologies, spatial audio, haptics and sensory augmentation.

Direct contact

Email: cesare.parise@liverpool.ac.uk

Affiliation: Department of Psychology, University of Liverpool, UK

University of Liverpool profile