Biology subjects

Nelson, M. J.

Publications and source records attributed to Nelson, M. J..

3 recordsLinked to original sources

bioRxiv2026

The All Window-Size Search method for improved statistical power in multiple comparisons correction

Correcting for multiple comparisons is a fundamental challenge throughout the biological sciences, particularly for data sampled over ordered continua such as time, space, or frequency. Existing approaches, including cluster-based permutation tests and threshold-free cluster enhancement (TFCE), leverage spatial or temporal contiguity but remain dependent on predefined statistical frameworks or thresholding procedures. Here we introduce the All Window-Size Search (AWSS) method, a permutation-based procedure that formally controls the family-wise error rate while adaptively searching across all contiguous window sizes and locations. For each permutation, test statistics are summed across every possible window, generating null distributions of maximal statistics at every window size. A second stage estimates the null distribution of the most significant uncorrected p-value that would arise from searching across all window sizes, allowing final p-values to be corrected for the adaptive search process itself. This procedure statistically formalizes the implicit multiscale search that investigators naturally perform when visually inspecting ordered data. Simulations with known ground-truth effects demonstrate that AWSS can provide substantially greater statistical power than conventional cluster-based permutation methods for broad, low-amplitude effects while maintaining appropriate family-wise error control. Because the framework is independent of any particular statistical test, it is readily applicable to diverse forms of one-dimensional ordered data. Here we test this application with simulations as well as using real human sEEG neural recording data. Future extensions will generalize the method to multidimensional spatial and spatiotemporal datasets, including neuroimaging and other high-dimensional biological data.

neuroscience↗

bioRxiv2026

Decoding and Characterizing the Intracranial Representation of Semantic Information

Brain-computer interfaces (BCIs) have achieved impressive performance by decoding motor and articulatory signals associated with speech production. However, considerably less is known about whether higher-level semantic representations can be decoded from human cortical activity. Demonstrating semantic decoding would advance both our understanding of language organization and the development of BCIs that rely on conceptual rather than purely articulatory information. We recorded intracranial neural activity from patients undergoing stereotactic electroencephalography (sEEG) for clinical epilepsy monitoring while they performed language tasks requiring semantic processing. High-gamma power was extracted from local field potentials and used to generate trial-level features for supervised machine-learning classification. Classification performance was evaluated using cross-validation. Semantic category information was decoded significantly above chance, with mean classification accuracy reaching 29.8% across 15 semantic categories (chance = 6.7%). These findings demonstrate that high-gamma activity contains information about conceptual category membership that can be extracted on individual trials. These results provide evidence that semantic information is accessible from intracranial population recordings and support the feasibility of semantic decoding as a complementary direction for future language BCIs. Beyond neuroprosthetic applications, this work contributes to understanding how conceptual knowledge is represented in the distributed human language network.

neuroscience↗

bioRxiv2026

Processing at Phrase Boundaries During Self-Paced Reading

Sentence comprehension requires the incremental construction of syntactic structure and semantic interpretation. Prior neural work (Nelson et al., 2017) identified key neural events at major phrase boundaries during sentence comprehension. To investigate a behavioral correlation of these processes, we used self-paced reading to examine the impact of syntactic phase boundaries, semantic congruence, and sentence structure on sentence processing. Participants read object-relative, subject-relative, and canonical control sentences one word at a time and a subsequent comprehension task. Reading times were analyzed relative to phrase boundaries, node-closing operations, and semantic congruence. Object-relative sentences produced the greatest processing difficulty, demonstrated by increased reading times and decreased comprehension accuracy. Reading times peaked at the phrase boundaries, indicating that processing costs are tied to constituent completion rather than individual lexical categories. Reading times also increased with the number of syntactic constituents completed at a phrase boundary. Agent-patient semantic congruence produced its largest effects in object-relative sentences, suggesting that semantic information interacts with syntactic computations when processing demands are greatest. These findings demonstrate that self-paced reading is sensitive to the incremental processing associated with syntactic constituent completion. Processing costs are tied more closely to phrase completion than to individual lexical categories, scale with the amount of syntactic structure completed at a boundary and interact with agent-patient semantic interpretation during object-relative sentence comprehension. Together, these findings support a view of sentence comprehension in which syntactic structure building and semantic interpretation proceed incrementally and interact continuously throughout online language processing.

neuroscience↗