Noise Correlations Study for Dyslexia

Overseen By Apoorva Bhandari, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Brown University

Must not be taking: Neuroleptics

Disqualifiers: Claustrophobia, Color blindness, Stroke, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 1

40 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how the brain processes noisy signals to enhance learning, particularly in individuals with dyslexia. Participants will engage in tasks that require decision-making based on changing visual cues, such as color and motion, through a dynamic perceptual discrimination task. The goal is to determine if the brain's handling of noise can accelerate learning. The study seeks adults with normal or corrected vision, who do not have conditions like color blindness or certain mental health issues. As an unphased trial, this study offers participants the chance to contribute to groundbreaking research that could improve learning strategies for individuals with dyslexia.

Will I have to stop taking my current medications?

The trial excludes participants taking neuroleptic medications, so if you are on these, you would need to stop. For other medications, the protocol does not specify any requirements.

What prior data suggests that this dynamic perceptual discrimination task is safe?

Research has shown that the dynamic perceptual discrimination task is generally easy for participants to handle. Studies have examined how people, including children with dyslexia, process and respond to certain sights and sounds. These studies have not found any direct evidence of negative effects from this task.

For instance, one study on visual perception found that both children with and without dyslexia could manage tasks involving quick changes in visual patterns without any reported problems. Another study examined auditory perception and did not find any harmful effects for participants.

Since this trial involves a task rather than taking medicine or undergoing a medical procedure, the risk of negative effects is low. The task involves interacting with visual and auditory information, which is generally safe. If there are any concerns, discussing them with the trial organizers is advisable. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the dynamic perceptual discrimination task for dyslexia because it offers a novel approach that goes beyond traditional reading interventions. Unlike standard treatments that often focus on phonics and reading practice, this task targets the brain's ability to integrate visual information and adapt decision-making processes. By requiring participants to continuously adjust their learning strategies based on shifting visual cues, this method aims to enhance cognitive flexibility and perceptual skills, which could lead to improved reading abilities. This innovative approach might address underlying neurological differences in dyslexia, offering new possibilities for treatment.

What evidence suggests that this dynamic perceptual discrimination task is effective for dyslexia?

Research has shown that people with dyslexia often struggle with tasks involving the differentiation of sounds or visual patterns. For example, studies have found that individuals with dyslexia might have difficulty distinguishing between different sounds or tones. One study noted that children with dyslexia may not benefit as much from repeated exposure to the same stimuli, a process known as perceptual anchoring. Despite these challenges, evidence suggests that certain training tasks can improve these skills. In this trial, participants will engage in the dynamic perceptual discrimination task, designed to help them change their learning strategies. This task may enhance their ability to process and respond to sensory information more effectively. ^{6 7 8 9 10}

Who Is on the Research Team?

Matthew Nassar, PhD

Principal Investigator

Brown University

Are You a Good Fit for This Trial?

This trial is for individuals with dyslexia or tinnitus. Specific eligibility criteria are not provided, but typically participants would need to be in good health and able to perform the tasks required by the study.

Inclusion Criteria

My vision is normal or can be corrected with glasses or contacts.

I am over 18 years old.

Exclusion Criteria

Conditions contraindicated for MRI such as surgical implant that is not MRI compatible, metal fragments in the body, tattoo with metallic ink

History of drug abuse and/or alcoholism

Claustrophobia

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Experimental Task

Participants engage in a dynamic perceptual discrimination task involving motion and color information, requiring adaptation to intra-dimensional shifts.

1 week

1 visit (in-person)

Scanning and Analysis

Participants undergo fMRI scanning to measure noise correlations and pupillometry as a proxy for neuromodulatory signaling.

6 months

Follow-up

Participants are monitored for safety and effectiveness after the experimental tasks and scanning sessions.

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Dynamic perceptual discrimination task

Trial Overview

The study investigates how 'noise correlations' between neurons affect learning. Participants will undergo a dynamic perceptual discrimination task while their brain activity is monitored using fMRI and pupillometry techniques.

How Is the Trial Designed?

Group I: Dynamic perceptual discrimination task Experimental Treatment 2 Interventions

The task featured two task conditions, each of which required the integration of information from both stimulus dimensions. In each condition, participants viewed a stimulus containing motion and color information and were required to specify one of two possible responses. Within each condition, rules and the response mapping changed occasionally, but always by changing on a fixed feature dimension (ie. rightward/purple, leftward/orange). These uncued intra-dimensional shifts involved translational shifts in the learning boundary, requiring them to adapt their decision making within a familiar dimension. These shifts compelled participants to continuously adjust their learning strategies by focusing on the most relevant feature dimension.

Who Is Running the Clinical Trial?

Brown University

Lead Sponsor

Trials

480

Recruited

724,000+

National Institute of General Medical Sciences (NIGMS)

Collaborator

Trials

315

Recruited

251,000+

Published Research Related to This Trial

Dyslexic children showed higher contrast thresholds in the presence of high noise for both magnocellular and parvocellular visual stimuli, indicating difficulties in noise exclusion.

When visual stimuli were presented without noise, dyslexic children performed similarly to non-dyslexic children, suggesting that their challenges are primarily related to processing noise rather than magnocellular visual processing.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Deficits in perceptual noise exclusion in developmental dyslexia. Sperling, AJ., Lu, ZL., Manis, FR., et al.[2022]

Adults with dyslexia showed improved motion coherence thresholds when the contrast of signal dots was higher than that of noise dots, supporting the noise exclusion hypothesis of dyslexia.

A cue directing attention to low contrast signal dots in high contrast noise helped adults with dyslexia achieve similar motion coherence thresholds as control participants, indicating that attention can mitigate some sensory processing deficits associated with dyslexia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The influence of contrast on coherent motion processing in dyslexia. Conlon, EG., Lilleskaret, G., Wright, CM., et al.[2022]

Dyslexics exhibit a specific perceptual deficit in integrating prior information with noisy observations, which is linked to their poor verbal memory and auditory skills, as shown through an auditory discrimination task involving a two-parameter computational model.

The study found that dyslexics underweight their implicit memory of past trials, leading to decreased ability to compensate for perceptual noise, while ERP measurements indicated that their brain responses do not effectively relate current observations to prior experiences.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A Computational Model of Implicit Memory Captures Dyslexics' Perceptual Deficits. Jaffe-Dax, S., Raviv, O., Jacoby, N., et al.[2022]

Developmental dyslexia (RD) is linked to low-level sensory-processing deficits that affect phonological skills, which are crucial for reading.

Increased neural excitability and noise in brain networks related to reading may contribute to the timing issues that underlie RD, suggesting a potential target for future interventions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Neural Noise Hypothesis of Developmental Dyslexia. Hancock, R., Pugh, KR., Hoeft, F.[2018]

Dyslexic children (48 participants) showed significantly higher internal noise estimates in motion discrimination tasks compared to typically developing children, indicating a potential impairment in their ability to process motion accurately.

The study found that perceptual differences in dyslexia extend beyond motion processing to orientation tasks, suggesting that these children may experience broader challenges in visual perception.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Integration of visual motion and orientation signals in dyslexic children: an equivalent noise approach. Manning, C., Hulks, V., Tibber, MS., et al.[2022]

Dyslexic individuals (D-LDs) show comparable performance to normal readers in tasks like speech perception in noise and tone comparison, indicating some preserved auditory processing abilities.

However, D-LDs struggle with forming perceptual anchors and do not benefit from stimulus-specific repetitions, suggesting their core deficit lies in dynamically constructing predictions, which may be linked to specific neuronal circuit mechanisms.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dyslexia and the failure to form a perceptual anchor. Ahissar, M., Lubin, Y., Putter-Katz, H., et al.[2022]

Adults with dyslexia showed poorer performance in naming speed tasks compared to typically achieving readers, indicating challenges in processing letters and objects, which are linked to reading abilities.

Neuroimaging revealed that dyslexic individuals had increased activation in the left hemisphere reading network and additional brain regions related to memory, suggesting that their brains may work harder to compensate for reading difficulties, while typically achieving readers showed different activation patterns associated with better performance.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Understanding the biological basis of dyslexia at a neural systems level. Al Dahhan, NZ., Kirby, JR., Brien, DC., et al.[2020]

Children with dyslexia showed significant difficulties in localizing sounds and discriminating words, especially in reverberant environments, compared to control children, indicating a potential challenge in classroom settings.

In particular, children with dyslexia had poor performance in word localization at specific angles (0º and +90º) and word discrimination at left angles in no-reverberant conditions, highlighting the impact of sound environment on their auditory processing.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Sound localization and word discrimination in reverberant environment in children with developmental dyslexia. Castro-Camacho, W., Peñaloza-López, Y., Pérez-Ruiz, SJ., et al.[2015]

A study involving 39 children (18 with dyslexia and 21 without) showed significant differences in brain connectivity, particularly in the left inferior frontal gyrus, before treatment, indicating distinct neural patterns associated with dyslexia.

After a three-week instructional treatment focused on linguistic skills, children with dyslexia exhibited normalized brain connectivity patterns, aligning with those of their peers without dyslexia, suggesting that targeted educational interventions can effectively alter brain function related to reading.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Abnormal fMRI Connectivity in Children with Dyslexia During a Phoneme Task: Before But Not After Treatment . Richards, TL., Berninger, VW.[2022]

A phonologically targeted training intervention improved reading performance in adults with developmental dyslexia, showing that specific behavioral training can lead to measurable gains in reading skills.

The improvements were linked to increased brain activity in key areas associated with reading, including the left hemisphere regions used by typical readers and compensatory activity in the right perisylvian cortex, indicating that different neural mechanisms are involved in recovery from dyslexia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Neural changes following remediation in adult developmental dyslexia. Eden, GF., Jones, KM., Cappell, K., et al.[2022]

Citations

1.

cell.com

cell.com/trends/cognitive-sciences/fulltext/S1364-6613(25)00248-7

Rapid decay of perceptual memory in dyslexia

Similar behavioral results were found in a homologous visual serial discrimination task in which participants were asked to judge which of ...

2.

sciencedirect.com

sciencedirect.com/science/article/pii/S1364661325002487

Rapid decay of perceptual memory in dyslexia

Faster decay of adaptation was found in the two-tone pitch discrimination task discussed above, as measured by early (100 and 200 ms delay) ...

3.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC2817563/

Psychophysical indices of perceptual functioning in dyslexia

Other studies have obtained variable results when studying deficits in frequency discrimination among poor readers (e.g., Ahissar et al., 2000; Amitay et al., ...

4.

frontiersin.org

frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2020.01158/full

Rhythmic Reading Training Compared With Hemisphere ...

Rhythm Perception and Reproduction. Rhythm and sound length discrimination abilities were assessed using the Rhythm Task from the “Q1 VATA Assessment Battery ...

5.

pure.mpg.de

pure.mpg.de/rest/items/item_3606446_2/component/file_3606448/content

Perceptual anchoring: Children with dyslexia benefit less ...

First evidence of electrophysiological indicators of perceptual anchoring from contextual repetitions comes from a tone- discrimination study in ...

6.

pubmed.ncbi.nlm.nih.gov

pubmed.ncbi.nlm.nih.gov/10992951/

Dynamic visual perception of dyslexic children

This study describes the capacity of children to detect fast changes of a small visual pattern. Three visual detection tasks for a group of normally reading ...

7.

sciencedirect.com

sciencedirect.com/science/article/abs/pii/S0093934X02005928

Developmental dyslexia and discrimination in speech ...

The aim of this study is to relate processes involved in auditory discrimination at the level of neuronal ensembles to evoked potentials and behavior by means ...

8.

frontiersin.org

frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2024.1245589/full

Amplitude rise time sensitivity in children with and without ...

Children's ability to discriminate rising frequency, duration, and intensity was also tested. ART discrimination in all 3 tasks was ...

9.

researchgate.net

researchgate.net/publication/265970352_Reading_Performance_Is_Enhanced_by_Visual_Texture_Discrimination_Training_in_Chinese-Speaking_Children_with_Developmental_Dyslexia

Reading Performance Is Enhanced by Visual Texture ...

The results revealed that the discrimination threshold SOAs of TDT were significantly higher for the children with dyslexia than for the control children before ...

10.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC10247831/

Perceived negative consequences of dyslexia

The dyslexia experience: Difference, disclosure, labelling, discrimination and stigma. Asia Pacific Journal of Developmental Differences ...