Is it possible that silent reading rate is the same as the most efficient listening rate? The hypothesis has been formulated in the past, but never got much traction because silent reading is almost twice as fast as typical speech. On the other hand, several studies have shown that listening comprehension retains high quality for spoken materials presented at speeds up to 275 words per minute (wpm), and a recent meta-analysis has also shown that reading rate is lower than often thought: 240-260 wpm on average. To address the question above, we ran a new study specifically comparing spontaneous silent reading rate with comprehension of speech presented at different rates within the same participants and using matched texts. We replicated the finding that listening comprehension was not hindered at the speech rate of 270 wpm but showed a steep decline at the rate of 315 wpm. Thus, the most efficient observed listening rate was on par with the spontaneous reading rate for the same texts (269 wpm on average). Therefore, we conclude that listening and reading follow the same time constraints. Public Significance StatementOne of the central and hotly debated questions in psychology of language is whether reading, listening, and speaking are served by fundamentally different or highly similar cognitive processes. An important piece of evidence for this debate is the speed at which production and comprehension of language takes place. This study is the first to show in the same group of participants that the timecompressed speech rate at which listening comprehension can be successful is on par with or exceeds the reading rate. This suggests that speed of comprehension is independent of modality (auditory or visual) and likely relies on highly similar cognitive processes.

ObjectiveTo determine the long-term safety and efficacy of repeated intrathecal (IT) administration of autologous mesenchymal stem cell-derived neural progenitors (MSC-NPs) in patients with progressive MS by evaluating subjects 2 years after treatment.MethodsTwenty subjects were enrolled as part of a phase I, open-label single-arm study of 3 IT injections of MSC-NPs spaced 3 months apart. Subjects were evaluated for adverse events and disability outcomes including the Expanded Disability Status Scale (EDSS) and the timed 25-foot walk (T25FW). Long-term evaluation was conducted 2 years after the third treatment. CSF was collected before and 3 months after treatment.ResultsEighteen of the 20 study participants completed the full 2-year follow-up protocol. There were no long-term adverse events associated with repeated IT-MSC-NP treatment. Seven subjects showed sustained improvement in EDSS after 2 years, although the degree of improvement was not maintained in 5 of the subjects. Three of the 10 ambulatory subjects showed sustained improvement in the T25FW after 2 years. CSF biomarker analysis revealed a decrease in C-C motif chemokine ligand 2 (CCL2) and an increase in interleukin 8, hepatocyte growth factor, and C-X-C motif chemokine ligand 12 (CXCL12) after treatment.ConclusionsSafety and efficacy of repeated IT-MSC-NP treatment was sustained for 2 years; however, the degree of disability reversal was not sustained in a subset of patients. CSF biomarkers altered in response to IT-MSC-NP treatment may reflect specific immunoregulatory and trophic mechanisms of therapeutic response in MS.Classification of evidenceThis study provides Class IV evidence that for patients with progressive MS, IT administration of MSC-NPs is safe and effective. The study is rated Class IV because of the absence of a non–IT-MSC-NP-treated control group.Clinicaltrials.gov identifierNCT01933802.

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