Development: Disorders

Talk Session: Monday, May 22, 2023, 10:45 am – 12:15 pm, Talk Room 1
Moderator: Shlomit Ben-Ami, MIT

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Talk 1, 10:45 am, 42.11

Developmental changes in occipital alpha rhythms: Recording EEG during public engagement events

Gemma Learmonth¹ (), Christopher Turner¹, Satu Baylan¹, Martina Bracco², Gabriela Cruz¹, Simon Hanzal¹, Marine Keime¹, Isaac Kuye¹, Deborah McNeill¹, Zika Ng¹, Mircea van der Plas¹, Manuela Ruzzoli³, Jelena Trajkovic¹, Domenica Veniero⁴, Sarah Wale¹, Sarah Whear¹, Gregor Thut¹; ¹University of Glasgow, Scotland, ²Hôpital de la Pitié Salpêtrière, Paris, France, ³Basque Center on Cognition Brain and Language (BCBL), Donostia/San Sebastian, Spain, ⁴University of Nottingham, UK

Statistical power in cognitive neuroscience experiments is often very low. Low sample size can reduce the likelihood of detecting real effects (false negatives) and increase the risk of detecting non-existing effects by chance (false positives). Here we present a study investigating a relatively unexplored method of increasing the sample size for simple electroencephalography (EEG) studies, of recording EEGs in the community during public engagement and outreach events. We collected data from 346 participants (189 females, age range 6-76 years) over 6 days, totalling 29 hours, at local science festivals. Occipital alpha activity (6-15 Hz) was recorded for 30 seconds using a single-channel electrode placed on the occipital midline (location Oz) while participants rested with their eyes closed. Using this community-based approach, we identified age-related changes in individual alpha frequency (IAF) and alpha power within a cross-section of the population. IAF increased throughout childhood, reaching a peak frequency in people in their early 20s, and slowed again in middle and older age. Alpha power reduced linearly with advancing age, but after accounting for aperiodic signal there was no reduction in alpha power over the lifespan. There were no associations between these EEG indices and self-reported fatigue, as measured by the Multidimensional Fatigue Inventory. Finally, we present a set of recommendations for researchers who wish to collect behavioural and EEG data within public engagement and outreach environments.

Acknowledgements: Funded by The Wellcome Trust

Talk 2, 11:00 am, 42.12

Reliable and predictive non-perceptual representations in primary visual cortex during attempts at visual imagery in aphantasia

Xinyu Zhang¹, Shuai Chang¹, Joel Pearson², Ming Meng¹; ¹South China Normal University, ²The University of New South Wales

Visual imagery is an important function of the human brain, and previous research on visual imagery reported that imagined stimuli can be decoded in early visual areas, while some other studies claimed that visual imagery generation relied more on higher-level cortical regions. Using fMRI the current study used multi-voxel decoding of attempts at generating visual mental imagery in early visual areas in individuals with aphantasia (lack the ability to voluntarily generate visual imagery). Participants with aphantasia (N = 14) and control (N = 18) groups were asked to generate mental imagery of Gabor patches of different orientations in the left or right visual field. We found that, activation patterns in the V1 and V2 of both aphantasic and control groups could be used to decode the imagined stimuli. However, for aphantasia, the patterns in early visual areas during imagery could not be used to decode the patterns during passively perceiving the same stimuli, whereas accuracies of this cross-task decoding for the control group were significant. These results suggest that aphantasic individuals, are not able to generate neural representations corresponding to perceptual sensory information in the early visual areas via voluntary visual imagery. Consistent with this notion, averaged BOLD activity in the early visual areas of the aphantasic individuals were also atypical during visual imagery, whereas during visual perception a typical contralateral visual field effect was found although slightly weaker than in the control group. For the first time, the current study reports that those with aphantasia do indeed have reliable and predictable neural patterns in early visual cortex during attempts at visual imagery, however these representations diverge from perceptual representations in the same individuals.

Talk 3, 11:15 am, 42.13

Responses to non-linguistic auditory transients in the medial geniculate nucleus are diagnostic for dyslexia in individual subjects

Keith Schneider¹ (), Qianli Meng²; ¹University of Delaware

Introduction: Hypotheses concerning the neurological basis of dyslexia, a common reading disorder, include dysfunction of the magnocellular system in the brain, abnormal temporal processing, and/or deficient phonological skills. Each of these theories has merit, but the link among them has not been identified. Methods: While being functionally imaged with a Siemens Prism 3T MRI scanner, nine subjects with dyslexia and eleven normal readers viewed high contrast checkerboard stimuli contrast reversing at various frequencies. We compared the responses to high and low frequency flicker. The subjects also listened to blocks of either transient (T) sounds with abrupt onsets or onsets, or sustained sounds (S) with ramped onsets and offsets. The auditory stimuli had no linguistic content and the blocks were independent of the visual stimuli. We computed a transient index (TI), defined as the difference in response amplitudes to the two blocks divided by their sum: TI = (T+S)/(T+S). We confined our functional analyses to the lateral (LGN) and medial (MGN) geniculate nuclei in the thalamus. Results: In the visual system, the normal readers exhibited a preference for higher frequency visual flicker in the magnocellular portion of the LGN, whereas the subjects with dyslexia did not. However, larger differences were found in the magnocellular portion of the MGN. Here in the subjects with dyslexia, we observed profoundly attenuated responses to non-linguistic transient but not sustained sounds compared to normal readers. This finding was highly consistent among the subjects in each group: the mean TI measurement in magnocellular slices of the MGN was a 95% accurate diagnostic for dyslexia among the individual subjects. Conclusion: Here we show that people with dyslexia have a selective impairment in the magnocellular portion of the medial geniculate nucleus, the auditory relay in the thalamus. Our finding identifies a core deficit potentially explaining three theories of dyslexia.

Acknowledgements: NIH/NEI 1R01EY028266 (KS)

Talk 4, 11:30 am, 42.14

The impact of cerebral visual impairment on school related competences in elementary school children

Sara Monteiro¹ (), Géraldine Hipp², Pascale Esch¹, Sonja Ugen¹; ¹Luxembourg Centre for Educational Testing, University of Luxembourg, ²Centre pour le Développement des Compétences relatives à la Vue, MENJE

Cerebral vision impairment (CVI) refers to a disturbance in visual processing related to damage to the visual areas in the brain and/or visual pathways. It is often assumed that CVI underlies functional vision difficulties. Previous research estimated that around 3% of mainstream educated elementary school children have CVI, potentially compromising these students’ school related performance. This study aimed to clarify how CVI impacts children’s performance in school competence tests. As part of the Luxembourgish school monitoring, the complete cohort of first graders (N = 5536) participated in three competence tests (mathematics, early literacy and listening comprehension) and student/parent questionnaires (background information). From this cohort, a representative sample (n = 1129) also participated individually in a visual competences’ screening (Evaluation of Visuo-Attentional Abilities battery, optometric measures). For this study, the sample was divided into children with CVI (n = 38) and children without CVI (n = 890) based on the clinical screening outcome. Children with other diagnoses were excluded from the sample (n = 201). Results from multiple regressions showed that CVI children obtained significantly lower scores than children without CVI for mathematics and early literacy but not for listening comprehension, when controlling for background characteristics (gender, socio-economic status, migration background, parental education, and home language). Listening comprehension was however a significant predictor for mathematics and early literacy for both groups, when controlling for background measures. More specifically, the explained variance of these models was higher for CVI children suggesting that they highly rely on auditory compensation strategies to complete written achievement tests. The prevalence rate for CVI was 3% within the representative sample, confirming internationally reported rates. These results show the impact of CVI on school related performances and the need for the implementation of a systematic early identification of children at risk.

Talk 5, 11:45 am, 42.15

Development of biological motion perception: Insights from late-sighted children

Shlomit Ben-Ami^1,2 (), Chetan Ralekar¹, Dhun Verma³, Kashish Tiwari³, Mrinalini Yadav³, Priti Gupta^3,4, Pragya Shah³, Suma Ganesh⁵, Nikolaus F. Troje⁶, Pawan Sinha¹; ¹MIT Department of Brain and Cognitive Sciences, Cambridge, MA, USA, ²Sagol School of Neuroscience, School of Psychological Sciences, Tel-Aviv University, Tel-Aviv, Israel, ³The Project Prakash Center, Delhi, India, ⁴Amarnath and Shashi Khosla School of Information Technology, Indian Institute of Technology, Delhi, India, ⁵Department of Ophthalmology, Dr. Shroff's Charity Eye Hospital, Delhi, India, ⁶York University, Toronto, Canada

Our visual system exhibits an exceptional capacity for processing the movement patterns of other humans (i.e., biological motion), which starts to emerge with very little visual experience. Even inexperienced individuals (human neonates, dark-reared chicks) can detect biological motion patterns. Patients treated for congenital cataracts can recognize human walking patterns in the first moments of unobstructed sight after a lifetime of near-blindness, not only from upright displays typical to real-life settings, but also from up-side-down displays. These demonstrations naturally lead to questioning whether visual exposure is central for acquiring this visual capacity, or if it is rather acquired phylogenetically or supported by non-visual factors (such as feedback from the observer's motor system). More intricate sensitivities, including walking direction discrimination and action recognition, are in place months after removal of congenital cataracts. However, it is not known if these capabilities are acquired after surgery or spared altogether. To probe this, twenty-five children with early-life visual deprivation and late sight onset participated in six tasks testing multiple aspects of their perception, starting prior to sight restoration, and continuing periodically for up to five years after. Our results indicate a gradual onset of abilities, modulated by the quality and extent of available visual input. Recognition of human walking patterns soon after sight onset is followed by a progression of other proficiencies: discrimination of walking direction, detection of coherent action patterns, and finally recognition of these actions. Perception of finer-resolution action patterns, including the ability to recognize fine-motor and face-movement displays, is not gained even over a period of five years. Intriguingly, recognition of complex two-person interaction sequences is exceptional, surpassing that of basic simple actions of a single individual. Our studies offer the opportunity to place different biological motion perception capabilities on a common developmental timeline, and reveal a stratification of their onset.

Acknowledgements: NEI (NIH) grant R01 EY020517 to PS 

Talk 6, 12:00 pm, 42.16

Reduced perception-action dissociation in children with amblyopia

Zoha Ahmad¹ (), Krista Kelly², Erez Freud¹; ¹York University, ²Retina Foundation of the Southwest

Visual illusions differentially affect perception and action, providing insights into the functional dissociation between vision for perception and vision for action. One such illusion is the Ponzo illusion where perceptual behaviors are modulated by the monocular depth cues, while grasping trajectories resist the effect of the illusion. Children with amblyopia (poor vision in one eye) provide the opportunity to examine an outstanding question - to what extent normal visual experience is critical for the development of the perception-action functional dissociation. Here, we examined the effect of the Ponzo illusion on perception and action in a group of children with amblyopia (n=20, 9.1±2.2 years old) compared to typically developed children (n=20, 9.2±2.1 years old). In the incongruent trials, two objects that differ in their real size (40 & 42 mm) were placed on an illusory Ponzo background to create a conflict between the real and the perceived size of the object and vice versa in the congruent trials. Control and amblyopic participants were asked to grasp (action task) and manually estimate the length of the object (perceptual task). Across conditions, we recorded hand kinematics using the Optitrack motion capture system. Both groups showed equal effect of the illusion in the perceptual task, such that the object placed on the far surface was perceived as longer compared to when placed on the near surface. In contrast, a clear differentiation between the groups was observed for the grasping task. While amblyopic participants’ Maximum Grip Apertures (MGAs) were modulated by the illusion, the MGAs of typically developed children evaded the illusion and were scaled to the real size of the object regardless of the object’s placement on the background. Taken together, our results provide novel evidence that atypical visual experience in childhood from amblyopia impacts the development of the dissociation between perception and action.

Acknowledgements: This research was funded by Natural Sciences and Engineering Research Council of Canada (NSERC) (EF), Vision Science to Applications (VISTA) program funded by the Canada First Research Excellence Fund (CFREF) (ZA&EF), and by the National Institutes of Health (NIH, EY028224) (KK).