Syntactic comprehension priming and lexical boost effects in older adults

The extent to which syntactic priming in comprehension is affected by ageing has not yet been extensively explored. It is further unclear whether syntactic comprehension priming persists across fillers in older adults. This study used a self-paced reading task and controlled for syntactic and lexical overlap, to (1) discover whether syntactic comprehension priming exists in older adults, across fillers, (2) to uncover potential differences between older and younger adults on priming measures, and (3) identify whether Working Memory or Processing Speed affect priming in older adults. Both older (Formula presented.) and Younger adults (Formula presented.) showed effects of syntactic priming and lexical boost. This suggests syntactic processing does not decline with age, and that abstract priming and the lexical boost are not dependent on residual activation or explicit retention in memory

In the prime of life: ERP evidence for syntactic comprehension priming in older adults

Background: Recent studies suggest older adults’ implicit learning of syntactic patterns remains largely intact. Syntactic priming has proven to be a sensitive tool to examine this implicit sensitivity. However, most priming studies with older adults have focused on production, and none have included an electrophysiological component. This study explores the neural correlates of syntactic priming in older adults’ comprehension. Method: We used a self-paced reading and event-related potential paradigm with groups of older and younger adults. Reduced Relative targets were primed, unprimed, or lexically boosted, while reading times and EEG recordings were obtained. Pre-tests of Working Memory and Processing Speed were also recorded. Results: Older adults showed intact priming and lexical boost on reading times, while lexical facilitation was dependent on syntactic overlap in the older but not the younger group. Syntactic priming was evident on N400 and P600 modulations on verbs and nouns in Reduced Relatives, and generally did not differ by age group. This suggests older and younger adults are equally susceptible to syntactic facilitation, and makes the case for more non-declarative, electrophysiological measurements of older adults’ sentence processing ability in future studies

A Novel EEG Paradigm to Simultaneously and Rapidly Assess the Functioning of Auditory and Visual Pathways

Objective assessment of the sensory pathways is crucial for understanding their development across the lifespan and how they may be affected by neurodevelopmental disorders (e.g., autism) and neurological pathologies (e.g., stroke, multiple sclerosis, etc.). Quick and passive measurements, for example using electroencephalography (EEG), are especially important when working with infants and young children, and with patient populations having communication deficits (e.g., aphasia). However, many EEG paradigms are limited to measuring activity from one sensory domain at a time, may be time consuming, and target only a subset of possible responses from that particular sensory domain (e.g., only auditory brainstem responses or only auditory P1-N1-P2 evoked potentials). Thus, we developed a new multisensory paradigm that enables simultaneous, robust, and rapid (6-12 minute) measurements of both auditory and visual EEG activity, including auditory brainstem responses (ABRs), auditory and visual evoked potentials, as well as auditory and visual steady-state responses. This novel method allows us to examine neural activity at various stations along the auditory and visual hierarchies with an ecologically valid continuous speech stimulus, while an unrelated video is playing. Both the speech stimulus and the video can be customized for any population of interest. Furthermore, by using two simultaneous visual steady-state stimulation rates, we demonstrate the ability of this paradigm to track both parafoveal and peripheral visual processing concurrently. We report results from twenty-five healthy young adults, which validate this new paradigm

Distinguishing underlying and surface variation patterns in speech perception

This study examines the relationship between patterns of variation and speech perception using two English prefixes: 'in-'/'im-' and 'un-'. In natural speech, 'in-' varies due to an underlying process of phonological assimilation, while 'un-' shows a pattern of surface variation, assimilating before labial stems. In a go/no-go lexical decision experiment, subjects were presented a set of 'mispronounced' stimuli in which the prefix nasal was altered (replacing [n] with [m], or vice versa), in addition to real words with unaltered prefixes. No significant differences between prefixes were found in responses to unaltered words. In mispronounced items, responses to 'un-' forms were faster and more accurate than to 'in-' forms, although a significant interaction mitigated this effect in labial contexts. These results suggest the regularity of variation patterns has consequences for the lexical specification of words, and argues against radical under-specification accounts which argue for a maximally sparse lexicon

Lexical Processing in Deaf Readers: An fMRI Investigation of Reading Proficiency

<div><p>Individuals with significant hearing loss often fail to attain competency in reading orthographic scripts which encode the sound properties of spoken language. Nevertheless, some profoundly deaf individuals do learn to read at age-appropriate levels. The question of what differentiates proficient deaf readers from less-proficient readers is poorly understood but topical, as efforts to develop appropriate and effective interventions are needed. This study uses functional magnetic resonance imaging (fMRI) to examine brain activation in deaf readers (N = 21), comparing proficient (N = 11) and less proficient (N = 10) readers’ performance in a widely used test of implicit reading. Proficient deaf readers activated left inferior frontal gyrus and left middle and superior temporal gyrus in a pattern that is consistent with regions reported in hearing readers. In contrast, the less-proficient readers exhibited a pattern of response characterized by inferior and middle frontal lobe activation (right>left) which bears some similarity to areas reported in studies of logographic reading, raising the possibility that these individuals are using a qualitatively different mode of orthographic processing than is traditionally observed in hearing individuals reading sound-based scripts. The evaluation of proficient and less-proficient readers points to different modes of processing printed English words. Importantly, these preliminary findings allow us to begin to establish the impact of linguistic and educational factors on the neural systems that underlie reading achievement in profoundly deaf individuals.</p> </div

Activations in proficient deaf readers for words versus false fonts, p<.005.

<p>Activations in proficient deaf readers for words versus false fonts, p<.005.</p

Activations in less-proficient deaf readers for words versus false fonts, p<.005.

<p>Activations in less-proficient deaf readers for words versus false fonts, p<.005.</p

False fonts with no tall letters (corresponds to words “manor”, “ounce” and “groom”).

<p>False fonts with no tall letters (corresponds to words “manor”, “ounce” and “groom”).</p

False fonts with tall letters (corresponds to words “stole”, “snort” and “pulse”).

<p>False fonts with tall letters (corresponds to words “stole”, “snort” and “pulse”).</p