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Teaser, summary, work performed and final results

Periodic Reporting for period 2 - EACISD (Embodied and Abstract Concepts in Sensory-motor Deprivation)

Teaser

How is information organized in the brain? Does our understanding of everyday concepts, actions and objects rely on our perceptual experience, and our ability to sense them? How would a rainbow be represented in people blind from birth? Can this uncover how abstract...

Summary

How is information organized in the brain? Does our understanding of everyday concepts, actions and objects rely on our perceptual experience, and our ability to sense them? How would a rainbow be represented in people blind from birth? Can this uncover how abstract information is coded in our brains? And more broadly, how does sensory experience affect our brain organisation and perception?
These puzzles are at core of modern cognitive and systems neuroscience and of our understanding of brain organization and function. The target of the research project was to address the role of sensory experience in concept representation and brain organization, by conducting a systematic interdisciplinary neuroimaging investigation of a combination of special populations, each deprived from birth from an entire sensory modality or ability (people born blind, deaf or without hands).

The research project addressed the neural correlates of concepts’ symbolic and sensory-independent representations, as well as their linked sensory-motor features. Furthermore, the project investigated the dependence on sensory-motor experience in brain organization for various regions, from the primary auditory and sensorimotor cortices to abstract representations of hand actions of others.
The project contributed to the state-of-the-art knowledge, strengthened the EU’s research collaboration network, and contributed to significant career development of the fellow.

Work performed

We performed several fMRI experiments on three different special populations to address the role of sensorimotor experience.

We studied the representation of non-sensory, semantic information in congenitally blind and upper limb dysplasic (ULD; born without hands) subjects. We scanned with fMRI as subjects were presented with concepts which are either sensorily concrete (e.g. every-day objects), fully abstract (e.g. “justice”), imperceptible by the different subject groups (impossible to physically perceive or utilize motorically; e.g. a rainbow to a man blind from birth, a bimanually-handled tool to a ULD person) and perceptible (sensorily accessible; e.g. rain to a blind man and a usable tool to a ULD person).
Different parts of the brain, in the left anterior temporal lobe (lATL), showed preference for imperceptible and perceptible concepts in the blind. These two regions in lATL belong to different functional neural networks, as found in brain resting-state fluctuations. These findings support classical cognitive theories, showing that concepts’ symbolic and non-sensory representations can be processed separately from sensory-motor features, and suggesting the division of labour in the lATL which may underlie this distinction. This work was published in Nature Communications (Striem-Amit et al., 2018b).
Strong effects in ATL were not found for tool-use experience in the ULD, where other areas in the occipitotemporal and parietal lobes are implicated in experience of manipulation, showing domain specificity of each system. This work is under preparation for publication.

Furthermore, we studied the dependence of perception and brain organization on sensorimotor experience.
In an fMRI experiment studying responses to tools, we found that despite having no experience in manipulating tools with their hands, the visual cortex of the ULDs contained the typical hand-tool- selectivity overlap seen in controls (Bracci et al., 2012), theorized to arise from the common use of tools and hands. This suggests that one’s own sensorimotor experience is not needed for this region’s development. These results were published in PNAS (Striem-Amit et al., 2017). In another experiment studying manual action perception, findings showed that the decoding of abstract hand actions was possible in the ULD visual cortex regions that process actions in controls, regardless of the motor ability to conduct them. This was published in Cerebral Cortex (Vannuscorps et al., 2018). In conjunction with findings of intact domain selectivity in people born blind (e.g. (Heimler et al., 2015)), these studies extend the notion that brain organization develops in each individual based on innate evolutionary-derived connectivity constraints (Mahon and Caramazza, 2009, 2011), and shows that it develops regardless of their experience in any one modality.

In an investigation of the organization of the early sensory cortices in sensory deprivation, we found that the deaf auditory cortex develops its typical topographic network organization without sensory inputs during development. This supports the role of innate (prenatal) connectivity development as an important factor in brain organization, and suggests the auditory cortex topographic patterns are found even in early sensory loss and in adulthood, potentially enabling rehabilitation beyond developmental critical periods. These results were published in in Scientific Reports ((Striem-Amit et al., 2016) .
In contrast, in the ULD the primary sensorimotor cortex area of the missing hands was responsive to multiple body parts, but mostly to those whose cortical territory is close by. This suggests that when partial input is provided (e.g. from other body parts), the competing input would take over the deprived cortical territory, based on proximity and connectivity principles. This study was published in PNAS (Striem-Amit et al., 2018a).

Overall, the project made new discoveries, contributing to our the

Final results

The project led to new discoveries beyond the scientific state of the art, contributing to our theoretical understanding of the brain and cognition. These findings were published in several scientific papers, including in high impact journals, and presented in multiple international scientific conferences, workshops and seminars. The study’s findings were also disseminated through press releases, popular science journals, social media and websites and made freely available to the public. The project led to the development of a new research line studying congenital hand absence and motor rehabilitation, which may contribute to clinical translational advancements in prostheses development. The project also created collaboration of several researchers in the US and Europe, extending and strengthening the EU’s research collaboration network.

Website & more info

More info: https://scholar.harvard.edu/striemamit.