Biology subjects

Adibi, I.

Publications and source records attributed to Adibi, I..

3 recordsLinked to original sources

bioRxiv2025

Over-Reliance on Prior Expectations in Relapsing-Remitting Multiple Sclerosis

Cognitive impairment is a common and disabling feature of multiple sclerosis (MS). Bayesian models of perception and action provide a powerful framework to better understand how cognitive processes are altered in MS. In this case-control study, we employed a time reproduction paradigm within a Bayesian framework to investigate the underlying mechanisms of cognitive dysfunction in patients with relapsing-remitting MS. We applied a modified Bayesian observer model, which partitions time reproduction into three stages: sensory measurement, time estimation, and motor response. We found that both MS and control groups showed a systematic bias in reproducing time, overestimating short intervals and underestimating long intervals. This bias was significantly larger in patients with MS compared with controls, reflecting an over-reliance on prior expectations relative to sensory-motor information. Computational modeling indicated that this increased bias in the MS group was driven by greater measurement noise during the sensory stage. Moreover, central tendency bias increases with age in healthy participants as reliance on prior expectations becomes stronger than sensory-motor evidence. Interestingly, we found that this age-related effect on bias was absent in patients with MS. Further analysis showed both younger and older patients performed equally biased, and their performance was similar to older healthy participants.

neuroscience↗

bioRxiv2024

Resource or slot model in visual working memory: Are they different?

When studying the working memory (WM), the slot model and the resource model are two main theories used to describe how information retention occurs. The slot model shows that WM capacity consists of a certain number of predefined slots available for information storage. This theory explains that there is a binary condition during information recall in which information is either wholly maintained within a slot or forgotten. The resource model gives a resolution-based approach defining a continuous resource able to be distributed among an unlimited number of items in the WM capacity. With newer hybrid models suggesting that WM may not strictly conform to one model, this study aimed to understand the relationship between the original models. By implementing correlational assessments of subjects performances in two different psychophysics tasks (analog recall paradigm with sequential bar presentation and delayed match-to-sample task (DMS) with checkerboard stimuli which are representative for resource and slot models, respectively), our study revealed significant correlations between WM performance (measured by DMS tasks) with recall error, precision, and sources of error (measured by sequential paradigm). Overall, the findings emphasize the importance of considering both models in understanding WM processes, shedding light on the debate between slot and resource models by demonstrating overlap in elements of both models.

neuroscience↗

bioRxiv2023

A Mechanistic Insight into Sources of Error of Visual Working Memory in Multiple Sclerosis

Working memory (WM) is one of the most affected cognitive domains in multiple sclerosis (MS), which is mainly studied by the previously established binary model for information storage (slot model). However, recent observations based on the continuous reproduction paradigms have shown that assuming dynamic allocation of WM resources (resource model) instead of the binary hypothesis will give more accurate predictions in WM assessment. Moreover, continuous reproduction paradigms allow for assessing the distribution of error in recalling information, providing new insights into the organization of the WM system. Hence, by utilizing two continuous reproduction paradigms, memory-guided localization (MGL) and analog recall task with sequential presentation, we investigated WM dysfunction in MS. Our results demonstrated an overall increase in recall error and decreased recall precision in MS. Furthermore, computational modeling of the results from the sequential paradigm determined that imprecision in decoding information and swap error (mistakenly reporting the feature of other presented items) were responsible for WM dysfunction in MS. Overall, this study offered a sensitive measure for assessing WM deficit and provided new insight into the organization of the WM system in MS population.

neuroscience↗