I Can Not See, I Can Not Hear, But Somehow I Know

Author: IMT School for Advanced Studies Lucca
Published: 2023/01/16 - Updated: 2025/12/06
Publication Details: Peer-Reviewed, Research, Study, Analysis
Category Topic: Medical Research - Related Publications

Page Content: Synopsis - Introduction - Main - Insights, Updates

Synopsis: This peer-reviewed research from neuroscientists at the IMT School for Advanced Studies Lucca and the University of Turin demonstrates that the brain contains an innate functional architecture enabling it to integrate information across sensory modalities - vision and hearing - independently of whether someone was born blind or deaf. Using fMRI imaging while blind, deaf, and typically developing participants engaged with the same film content (either audio or visual versions), researchers identified the superior temporal cortex as the region responsible for this cross-sensory binding, showing that the brain's ability to match a visual image of a dog with the sound of barking requires no prior sensory experience to develop.

The findings have direct implications for individuals with sensory disabilities, suggesting their brains operate with the same fundamental integration capacity as those without sensory loss, which in turn supports arguments for more inclusive educational and social approaches rather than assumptions based on sensory capability alone - Disabled World (DW).

Definition: Nature Versus Nurture Debate: The nature vs. nurture debate is the scientific, cultural, and philosophical debate about whether human culture, behavior, and personality are caused primarily by nature or nurture. Nature is often defined in this debate as genetic or hormone-based behaviors, traits, and dispositions, while nurture is most commonly defined as environment, culture, and experience. Whether nature or nurture plays a bigger role in personality and development is one of the oldest philosophical debates within psychology. Instead of defending extreme nativist or nurturist views, most psychological researchers are now interested in investigating how nature and nurture interact in a host of qualitatively different ways.

Introduction

A Modality-Independent Proto-Organization of Human Multisensory Areas - Nature Human Behavior.

To build a representation of the external world and give it a coherent sense, our brain needs to process and integrate information from all senses, including vision and hearing. But whether this "multisensory processing" is innate and present from birth in the human brain or depends on experience remains an open debate.

Now, a novel study by an Italian team of neuroscientists from the IMT School for Advanced Studies Lucca and the University of Turin shows that the ability of the brain to represent coherent information across senses primarily relies on an innate functional architecture of specific regions in the brain cortex that works independently from any sensory experience acquired after birth. The study, published in the current issue of Nature Human Behaviour, adds to the old "nature versus nurture" debate and brings further weight to the evidence that brain architecture can develop independently from sensory experience.

Main Content

Brain's Sensory Integration Built In, Not Learned

"We hypothesized that some areas of the cortex, known to process more than just one sensory input, may possess a predetermined structure that aids perception of sensory events by matching coherent inputs across sensory modalities," explains Emiliano Ricciardi, professor of psychobiology and psychophysiology at the IMT School, who led the research.

"Since this idea can hardly be tested at birth, we purposely determined the consistent responses across adults deprived since the birth of either sight or hearing: any shared brain response across these individuals, whose post-natal experiences inevitably differ, would be indicative of an innate computation."

To conduct the study, the researchers compared the brain activity in three groups: people with typical development, congenitally blind, and congenitally deaf people. The specific brain response was assessed with Magnetic Resonance Imaging (fMRI) while the subjects were watching or listening to the same edited version of the Walt Disney movie "101 Dalmatians". Specifically, blind individuals listened to the acoustic version of the movie, while deaf people watched the visual version. The same experimental conditions were adopted with typically developed sighted and hearing individuals. Brain responses were then compared.

"By measuring brain synchronization between individuals who were watching the movie and those who were listening to the narrative, we identified the regions in the brain which coupled information across sensory modalities," explains Francesca Setti, a researcher in neuroscience at IMT School and first author of the paper.

"We found that a specific patch of cortex, the superior temporal cortex, endorses a representation of the external world that is shared across modalities and is independent of any visual or acoustic experience since birth, as the same representation is present in blind and deaf participants as well."

Setti and colleagues show that the human superior temporal cortex has an innate functional architecture that allows it to represent coherent information across senses and does not require a prior sensory experience to develop. Two cartoon characters play a card game of finding the right match between an auditory and a visual stimulus associated with the same object (for instance, the muzzle of a dog and its sound represented through the onomatopoeic word woof). On the wall, a picture of the brain, in pixel art style, depicts the areas associated with processing auditory and visual stimuli (in yellow and blue, respectively) and highlights the role of the superior temporal cortex in binding information across senses (blue and yellow). The experimental paradigm is represented in the foreground. One character is blindfolded while the other wears a bandage on the ears to represent the experimental samples and the study conditions (congenitally blind and deaf participants; typically developed presented with audio-only or visual-only stimulation). The two cards that are flipped artistically illustrate the stimulation used in the study, which is the action movie 101 Dalmatians - Illustration Credit: Francesca Setti, IMT School for Advanced Studies Lucca.

In their work, the researchers provided evidence that this area of the brain cortex encodes various basic properties of stimuli, and couples information from the two different senses, the visual and the acoustic channel.

"In simple words, this is the area where the visual image of a 'dog' is coupled with the acoustic signal of the dog barking, making clear to our brain that the two stimuli coming through two different senses refer to the same 'object' in the world," says Setti.

"Overall, these data show that basic visual and auditory features are responsible for the neural synchronization between blind and deaf individuals," adds Ricciardi.

"This research extends results from previous studies by several labs, including ours, that consistently indicate that most of the large-scale morphological and functional architecture in the human brain can develop and function independently from any sensory experience" comments Pietro Pietrini, Director of MoMiLab (Molecular Mind Laboratory) at the IMT School and coauthor of the study.

"The wider implications are that we should promote more inclusive educational strategies and social policies for individuals with sensory disabilities, as their brains are the same," concludes Pietrini.

Insights, Analysis, and Developments

Editorial Note: The results of this research carry particular significance not merely as a confirmation of neural plasticity, but as a biological argument for reconsidering how societies structure opportunities and access for people with sensory disabilities. If the brain's most fundamental architecture for understanding the world operates independently of whether one sees or hears, then the barriers many blind and deaf individuals face are not neurological deficits but social ones - stemming from environments and systems designed without their participation. The study thus transforms what might seem like a purely academic question about nature versus nurture into a practical mandate: our responsibility lies not in fixing brains, but in building a world where all brains, regardless of sensory input, can fully participate - Disabled World (DW).

Attribution/Source(s): This peer reviewed publication was selected for publishing by the editors of Disabled World (DW) due to its relevance to the disability community. Originally authored by IMT School for Advanced Studies Lucca and published on 2023/01/16, this content may have been edited for style, clarity, or brevity.