Biology subjects

Pylkkänen, L.

Publications and source records attributed to Pylkkänen, L..

14 recordsLinked to original sources

bioRxiv2026

When tigers are not animals: The neural disappearance of animacy as a function of linguistic structure

In language, not only do sentence meanings depend on how words are structured together, but word meanings also depend on their roles in the structure. While we have some understanding of how the brain grasps complex meanings built from simpler parts, we know far less about how linguistic structure reshapes the meanings of the words themselves. Here we used magnetoencephalography (29 human participants: 16 women, 9 men, 4 nonbinary) to track the neural dynamics of animacy, a fundamental semantic feature that guides conceptual organization. Regardless of how animacy was operationalized (as discrete semantic categories or more abstractly), the same pattern emerged: When word-level animacy conflicted with the structural context, it disappeared from the word's neural representation. Our findings show how compositional processes rapidly reconfigure neural traces of word meanings, allowing phrase-level meanings to even override word-level features.

neuroscience↗

bioRxiv2026

No tiger in plastic tiger: Local linguistic context alters the neural representations of individual words

Language is vastly ambiguous, yet in context our brains resolve ambiguity effortlessly. This is particularly evident at the lexical level: Although most words can convey a wide range of related meanings, humans rapidly and automatically select the one appropriate for the context. We investigated the neural mechanisms underlying this process by focusing on a case where, intuitively, one meaning appears more basic than another: nouns describing animate entities, such as tiger, which can also refer to representations of those entities when combined with a material modifier, as in plastic tiger. Using magnetoencephalography, we decoded animacy from neural signals and found that even in such cases, our approach revealed no evidence that the tiger in plastic tiger is represented as a sentient animal in any stage of processing. Instead, phrase-level animacy--plastic tiger as inanimate--was decodable as early as 210 ms post-stimulus onset and persisted for several hundred milliseconds. These findings challenge theories assuming a shift from a basic sense of a word to a more derived one, highlighting instead the role of compositional context in shaping word meanings.

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bioRxiv2026

Comparing serial and parallel language input: Shared neural representations with distinct encoding strengths

Language can be experienced in highly serial form, as in speech, or in fully parallel form, as in text, yet how our brains adapt to differences in seriality is not understood. Here, we held modality constant (visual) and examined whether processing mechanisms underlying grammaticality detection are similar under Rapid Serial Visual Presentation (RSVP) and Rapid Parallel Visual Presentation (RPVP). To identify shared neural representations of grammaticality, we trained a classifier on magnetoencephalography (MEG) responses to grammatical and ungrammatical three-word phrases in one presentation mode and tested its generalization to the other. Behaviorally, accuracy was higher and reaction times faster for grammatical vs. ungrammatical phrases across presentation modes. Neurally, cross-presentation decoding revealed shared representations of grammaticality at word 2 across train-test directions--albeit with different latencies and durations--and an early shared representation at word 3 when trained on RPVP. We take the bidirectional representations at word 2 to capture distinct but presentation-invariant combinatorial processes and the asymmetry at word 3 as reflecting stronger global structure encoding in RPVP.

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bioRxiv2026

Temporal constraints on the neural signatures of narrative processing

How the brain constructs meaning across extended contexts remains poorly understood. While neural responses to words and sentences are well characterized, much less is known about the brain mechanisms supporting narrative comprehension. Sentence-level studies suggest that neural activation increases as word meanings are integrated into sentence meaning. At the discourse level, theories propose that narratives depend on situation models, possibly engaging networks beyond core language regions, including the default mode network. Because narrative comprehension unfolds over longer timescales, processing time may be a bottleneck. In this MEG study, we tested how representation size and presentation rate shape neural responses by varying linguistic structure (words, sentences, stories) and the speed of visual text in 1-4-word chunks. We found an early bilateral story effect in visual cortex, followed by a spatiotemporal progression of activity along the temporal lobes that culminated in a three-way contrast among word lists, sentence lists, and stories. Faster presentation altered this pattern: the left-lateralized story effect disappeared, and the right-lateralized effect became more spatially restricted. Under Fast presentation, significant effects were limited to left lateral language cortex distinguishing coherent inputs from word lists, and to two right-hemisphere story effects in extended language regions. We also observed a context effect in the Slow Story condition, with neural responses remaining constant as the narrative unfolded while they increased in the SentenceList and WordList conditions. This effect was absent under Fast presentation, suggesting story-specific comprehension that is temporally constrained. Together, the findings identify temporal constraints as a key determinant of the neural signatures of narrative processing.

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bioRxiv2025

A Unified Neural Timecourse for Words, Phrases, and Sentences: MEG Evidence from Parallel Presentation

Recent behavioral and neural research on reading shows that humans can extract syntactic structure from short sentences within a fraction of a second--faster than many estimates for recognizing the meaning of a single word. This challenges a core assumption of many language processing models: that combinatory operations depend on prior lexical access. Further, studies using parallel presentation of full sentences have revealed electrophysiological responses remarkably similar to those well established for single words. This raises the question of whether words, phrases, and sentences all move through the same processing stages, regardless of syntactic complexity. Using magnetoencephalography (MEG), we examined how single words, phrases, and sentences are processed when all visual information is available at once. Across all three levels, we observed highly similar waveform dynamics, with early responses reflecting bottom-up detection of form followed by activity in the left anterior and posterior temporal cortices and vmPFC consistent with combinatory processing. Of these regions, the left anterior temporal lobe (LATL) showed effects of bigram frequency suggestive of serial left-to-right dynamics. Together, these results support a Global-to-Serial Assembly (GLOSA) model in which the brain first detects the global form of the stimulus in a snapshot-like manner and then probes its combinatory properties through partially serial processes.

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bioRxiv2025

Reading ahead: Localized neural signatures of parafoveal word processing and skipping decisions

Visual reading proceeds fixation-by-fixation, with individual words recognized and integrated into evolving conceptual representations within only hundreds of milliseconds. This relies, in part, on interactions between cognitive and oculomotor systems, such that linguistic properties of words influence eye movements and fixation durations. When and where do these influences arise in the neural processing of an incoming word? To answer this, we combined magnetoencephalography (MEG) with eye-tracking in a natural story-reading paradigm. We replicated past findings that word frequency and predictability have additive influences on fixation durations. Next, we identified putative generators of these influences in localized brain activity time-locked to fixation onsets. Both properties independently influenced neural responses in left occipitotemporal and ventral temporal areas, at latencies early enough to influence subsequent saccade planning. These effects began in posterior areas (the left lingual gyrus, lateral occipital cortex) during parafoveal word processing, and shifted more anteriorly (the inferior temporal and parahippocampal gyri) when the word was fixated in foveal vision. Evidence for parallel processing of both parafoveal and foveal words was observed in the left posterior fusiform, which housed near-simultaneous effects of both the fixated and upcoming words frequency and surprisal. We also found that parafoveal processing in this region, together with the left middle temporal gyrus, distinguished whether an upcoming word was skipped or fixated. These results suggest that during natural visual reading, word recognition and integration begin parafoveally, underpinned by a left-lateralized occipitotemporal system, where word processing rapidly exerts downstream influences on eye movement decisions.

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bioRxiv2024

Multi-talker speech comprehension at different temporal scales in listeners with normal and impaired hearing

Comprehending speech requires deciphering a range of linguistic representations, from phonemes to narratives. Prior research suggests that in single-talker scenarios, the neural encoding of linguistic units follows a hierarchy of increasing temporal receptive windows. Shorter temporal units like phonemes and syllables are encoded by lower-level sensory brain regions, whereas longer units such as sentences and paragraphs are processed by higher-level perceptual and cognitive areas. However, the brains representation of these linguistic units under challenging listening conditions, such as a cocktail party situation, remains unclear. In this study, we recorded electroencephalogram (EEG) responses from both normal-hearing and hearing-impaired participants as they listened to individual and dual speakers narrating different parts of a story. The inclusion of hearing-impaired listeners allowed us to examine how hierarchically organized linguistic units in competing speech streams affect comprehension abilities. We leveraged a hierarchical language model to extract linguistic information at multiple levels--phoneme, syllable, word, phrase, and sentence--and aligned these model activations with the EEG data. Our findings showed distinct neural responses to dual-speaker speech between the two groups. Specifically, compared to normal-hearing listeners, hearing-impaired listeners exhibited poorer model fits at the acoustic, phoneme, and syllable levels as well as the sentence levels, but not at the word and phrase levels. These results suggest that hearing-impaired listeners experience disruptions at both shorter and longer temporal scales, while their processing at medium temporal scales remains unaffected.

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bioRxiv2024

Rapid visual form-based processing of (some) grammatical features in parallel reading: An EEG study in English

Theories of language processing - and typical experimental methodologies - emphasize the word-by-word processing of sentences. This paradigm is good for approximating speech or careful text reading, but arguably, not for the common, cursory glances used while reading short sentences (e.g., cellphone notifications, social media posts). How can we interpret a sentence in a single glance? In an electroencephalography (EEG) study, brain responses to grammatical sentences (the dogs chase a ball) presented for 200ms diverged from non-lexical consonant strings (thj rjxb zkhtb w lhct) [~]160ms post-sentence onset and from scrambled constructions (a dogs chase ball the) [~]250ms post-sentence onset, demonstrating - at different time points - rapid recognition and cursory analysis of linguistic stimuli. In the grammatical sentences, unigram probability correlated with EEG data [~]150-300ms post-sentence onset, and probability of the word given its context estimated by BERT correlated with EEG data after [~]700-800ms. EEG responses did not diverge between grammatical sentences and their counterparts with ungrammatical agreement (the dogs chases a ball), although EEG responses did diverge for plural vs. singular morphology at [~]200ms. These results suggest that at-a-glance reading is possible, based on coactivation of individual lexical items, morphological structures, and constituent structure at [~]200-300ms, but that words are not integrated into a coherent syntactic/semantic analysis, as evidenced by the substantially later responses to BERT probability and the absence of sensitivity to agreement errors.

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bioRxiv2024

The spatiotemporal dynamics of bottom-up and top-down processing during at-a-glance reading

Like all domains of cognition, language processing is affected by top-down knowledge. Classic evidence for this is missing blatant errors in the signal. In sentence comprehension, one instance of this is failing to notice word order errors, such as transposed words in the middle of a sentence: you that read wrong (Mirault et al., 2018). Our brains seem to fix such errors, since they are incompatible with our grammatical knowledge. But how do our brains do this? Following behavioral work on inner transpositions, we flashed four-word sentences for 300ms using rapid parallel visual presentation (RPVP, Snell and Grainger, 2017). We compared their magnetoencephalography responses to fully grammatical and reversed sentences. Left lateral language cortex robustly distinguished grammatical and reversed sentences starting at 213ms. Thus, the influence of grammatical knowledge begun rapidly after visual word form recognition (Tarkiainen et al., 1999). At the earliest stage of this neural "sentence superiority effect," inner transpositions patterned between grammatical and reversed sentences, showing evidence that the brain initially "noticed" the error. However, a hundred millisecond later, the inner transpositions became indistinguishable from the grammatical sentences, suggesting that at this point, the brain had "fixed" the error. These results show that after a single glance at a sentence, syntax impacts our neural activity almost as quickly as higher-level object recognition is assumed to take place (Cichy et al., 2014). The earliest stage involves a detailed comparison between the bottom-up input and grammatical knowledge, while shortly afterwards, knowledge can override an error in the stimulus.

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bioRxiv2023

Semantic composition in experimental and naturalistic paradigms

Naturalistic paradigms using movies or audiobooks have become increasingly popular in cognitive neuroscience, but connecting them to findings from controlled experiments remains rare. Here, we aim to bridge this gap in the context of semantic composition in language processing, which is typically examined using a "minimal" two-word paradigm. Using magnetoencephalography (MEG), we investigated whether the neural signatures of semantic composition observed in an auditory two-word paradigm can extend to naturalistic story listening, and vice versa. Our results demonstrate consistent differentiation between phrases and single nouns in the left anterior and middle temporal lobe, regardless of the context. Notably, this distinction emerged later during naturalistic listening. Yet this latency difference disappeared when accounting for various factors in the naturalistic data, such as prosody, word rate, word frequency, surprisal, and emotional content. These findings suggest the presence of a unified compositional process underlying both isolated and connected speech comprehension.

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bioRxiv2020

From letters to composed concepts: A magnetoencephalography study of reading

Language comprehension requires the recognition of individual words and the combination of their meanings to yield complex concepts or interpretations. Rather than simple concatenation, this combinatory process often requires the insertion of unstated semantic material between words, based on thematic or feature knowledge of the concepts. For example, the phrase horse barn is not interpreted as a blend of a horse and a barn, but specifically a barn in which horses are kept. Mounting evidence suggests two cortical semantic hubs, in left temporoparietal and anterior temporal cortex, underpin thematic and feature concept knowledge, but much remains unclear about how these putative hubs contribute to combinatory language processing. Using magnetoencephalography, we contrasted source-localized responses to modifier-noun phrases involving thematic relations vs. feature modifications, while also examining how lower-level orthographic processing fed into responses supporting word combination. Twenty-eight participants completed three procedures examining responses to letter-strings, adjective-noun phrases, and noun-noun combinations that varied the semantic relations between words. We found that while color + noun phrases engaged the left anterior temporal lobe (150-300 ms after phrasal head), posterior temporal lobe (150-300 ms), and angular gyrus (300-450 ms), only left posterior temporal lobe responses were sensitive to implicit thematic relations between composing nouns (150-300 ms). We additionally identified a left temporo-occipital progression from orthographic to lexical processing, feeding into ventral anterior areas engaged in the combination of word meanings. Finally, by examining source signal leakage, we characterized the degree to which these responses could be distinguished from one another, using linear source estimation.

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bioRxiv2020

Neural representation of words within phrases: Temporal evolution of color-adjectives and object-nouns during simple composition

In language, stored representations of lexical items combine into an infinitude of complex expressions. While the neuroscience of composition has begun to mature, we do not yet understand how the stored representations evolve and morph during composition. New decoding techniques allow us to crack open this very hard question: we can train a model to recognize a representation in one context or time-point and assess its accuracy in another. We combined the decoding approach with magnetoencephalography recorded during a picture naming task to investigate the temporal evolution of noun and adjective representations during speech planning. We tracked word representations as they combined into simple two-word phrases, using single words and two-word lists as non-combinatory controls. We found that nouns were generally more decodable than adjectives, suggesting that noun representations were stronger and/or more consistent across trials than those of adjectives. When training and testing across contexts and times, the representations of isolated nouns were recoverable when those nouns were embedded in phrases, but not so if they were embedded in lists. Adjective representations did not show a similar consistency across isolated and phrasal contexts. Noun representations in phrases also sustained over time in a way that was not observed for any other pairing of word class and context. These findings offer a new window into the temporal evolution and context sensitivity of word representations during composition, revealing a clear asymmetry between adjectives and nouns. The impact of phrasal contexts on the decodability of nouns may be due to the nouns status as head of phrase--an intriguing hypothesis for future research.

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bioRxiv2020

Neural correlates of modal displacement and discourse-updating under (un)certainty

A hallmark of human thought is the ability to think about not just the actual world, but also about alternative ways the world could be. One way to study this contrast is through language. Language has grammatical devices for expressing possibilities and necessities, such as the words might or must. With these devices, called "modal expressions," we can study the actual vs. possible contrast in a highly controlled way. While factual utterances such as "There is a monster under my bed" update the here-and-now of a discourse model, a modal version of this sentence, "There might be a monster under my bed," displaces from the here-and-now and merely postulates a possibility. We used magnetoencephalography (MEG) to test whether the processes of discourse updating and modal displacement dissociate in the brain. Factual and modal utterances were embedded in short narratives, and across two experiments, factual expressions increased the measured activity over modal expressions. However, the localization of the increase appeared to depend on perspective: signal localizing in right temporo-parietal areas increased when updating others beliefs, while frontal medial areas seem sensitive to updating ones own beliefs. The presence of modal displacement did not elevate MEG signal strength in any of our analyses. In sum, this study identifies potential neural signatures of the process by which facts get added to our mental representation of the world.

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bioRxiv2018

Isolating syntax in natural language: MEG evidence for an early contribution of left posterior temporal cortex

Syntax is the engine that allows us to create an infinitude of linguistic expressions, and the construction of syntactic structures, such as noun phrases and verb phrases, is considered a fundamental component of language processing. Nevertheless, insights concerning the neurobiological basis of syntax have remained elusive, in part because it is difficult to isolate syntax from semantic composition. Consequently, many studies of syntax have relied on meaningless artificial stimuli, such as jabberwocky expressions or artificial grammars. However, while pure manipulations of syntax are challenging to design, natural language grammars do have a sparse set of constructions presenting this possibility. Here we examined one such case, English post-nominal adjectives (mountain TALL enough for a strenuous hike), which were contrasted with semantically parallel but structurally simpler noun-adjective sequences in an MEG experiment. We observed a sharp activity increase in the left posterior temporal lobe (PTL) when syntactic composition was more straightforward, approximately 200 ms after adjective onset. The semantic fit between the noun and adjective was also varied, but this affected anterior temporal cortex, consistent with prior work. These findings offer a unique demonstration of the relevance of posterior temporal cortex for syntactic processing in natural language. We also present connectivity evidence that the syntax-related PTL responses were relayed to ipsilateral inferior frontal and anterior temporal regions. The combined results draw an initial picture of the rapid spatio-temporal dynamics of the syntactic and semantic composition network in sentence processing.

neuroscience↗