Cognitive Neuropsychology最新文献

Blind participants tend to encode sensory details of encounters with stimuli they will later recall or recollect, whereas sighted individuals tend to abstract meaning from sensory information when encoding memories. Here we ask whether blind individuals' use of perceptual in addition to semantic encoding extends to a task-word learning-whose purpose amounts to semantically encoding the word and definition. After studying the definitions of spoken or written words, blind braille readers (n = 23) and sighted print readers (n = 20) re-encountered each word and indicated whether it was previously presented in the same modality. Analyses showed blind participants had better recall of modality even for words they had read (i.e., processed tactually), indicating their use of perceptual encoding may be automatically deployed in situations where it is unnecessary for the task. We recommend further research on individual differences in perceptual encoding within and across groups and its potential costs and benefits.

Lexical retrieval is commonly studied in the context of single words, even though words are usually produced within sentences. We present a framework for investigating the interplay between lexical retrieval, argument structure, and morphology. We propose a model for the retrieval of alternating-verbs, which, in Hebrew, are morphologically marked based on argument structure. We tested 23 Hebrew-speakers with aphasia, first identifying their functional locus of impairment within a lexical retrieval model for single words, and then administering a test battery to assess their production of alternating verbs within sentences. We found that the conceptual system, the semantic lexicon, the syntactic lexicon, the phonological output lexicon, and the phonological output buffer, each plays a unique role in retrieving morphologically-complex verbs, yielding a different error pattern when impaired. These error patterns are predicted by the proposed model for retrieval of alternating verbs with their argument structure and morphology.

We investigated visual working memory (VWM) for faces and two novel non-face pattern types (Blobs and Mondrians) in individuals with developmental prosopagnosia (DP) and age-matched controls. Participants completed both simultaneous and sequential encoding tasks, judging whether a probe item matched one shown at encoding. DPs showed a consistent face disadvantage across both encoding types, while controls showed a face advantage, but only during simultaneous encoding. Compared to controls, DPs had impaired face VWM in both tasks but performed equivalently for abstract shapes and patterns. Face VWM impairments in DP were not exacerbated by increased memory load or updating demands, suggesting these deficits stem from face perception difficulties that affect encoding rather than general VWM mechanisms. Our group-based analyses were supplemented by individual case statistics. Overall, our findings indicate that DPs do not exhibit general VWM deficits, but rather specific difficulties with face processing across formats.

The role of stems and prefixes in complex nonword reading was investigated in unimpaired readers and five individuals with acquired dyslexia. All participants completed a reading aloud task (and the reading impaired individuals also completed a repetition task) with four different types of nonwords: prefix + stem (refront), non-prefix + stem (tefront), prefix + non-stem (refrint), non-prefix + non-stem (tefrint); and prefixed and non-prefixed filler words. The unimpaired readers responded fastest to nonwords containing two morphemes (prefix + stem), slower to nonwords with one morpheme (non-prefix + stem; prefix + non-stem), and slowest in the non-morphemic control condition (non-prefix + non-stem), providing evidence for the added benefit of prefixes and stems during reading. The five reading impaired individuals showed facilitatory morpheme effects across both tasks, but stem-effects were more robust than affix-effects. There was no difference between the prefixed and non-prefixed words in any of the data. The impact of morphological structure on nonword reading and repetition points to the important role of morphemes across different modalities..

This study examined how semantic characteristics of verbal cues impact naming, focusing on cue distinctiveness, defined as the degree to which a semantic cue is uniquely associated with a target. Using a novel naming paradigm, we presented word pairs representing semantic features to elicit naming responses. These verbal cues were categorized as distinctive (e.g., "moo-milk" for COW) or shared (e.g., "feathers-pink" for FLAMINGO), and targets were classified as living or nonliving. Distinctive cues significantly improved naming accuracy and speed, with a greater benefit for living items. A follow-up analysis examined graded effects of distinctiveness while accounting for associative strength. Both cue distinctiveness and associative strength facilitated naming speed overall. However, when distinctiveness was residualized against associative strength, the effect remained stronger for living items, although other semantic factors are also discussed. This study introduces a novel paradigm for evaluating semantic factors on naming, with potential future application to clinical populations.

Many aspects of human performance require producing sequences of items in serial order. The current study takes a multiple-case approach to investigate whether the system responsible for serial order is shared across cognitive domains, focusing on working memory (WM) and word production. Serial order performance in three individuals with post-stroke language and verbal WM disorders (hereafter persons with aphasia, PWAs) were assessed using recognition and recall tasks for verbal and visuospatial WM, as well as error analyses in spoken and written production tasks to assess whether there was a tendency to produce the correct phonemes/letters in the wrong order. One PWA exhibited domain-specific serial order deficits in verbal and visuospatial WM. The PWA with verbal serial order WM deficit made more serial order errors than expected by chance in both repetition and writing-to-dictation tasks, whereas the other two PWAs showed no serial order deficits in verbal WM and production tasks. These findings suggest separable serial order systems for verbal and visuospatial WM and a shared system for serial order processing in verbal WM and word production. Implications for the domain-generality of WM, its connection to language production, and serial order processing across cognitive functionssc are discussed.

Coma and disorders of consciousness (DoC) are common manifestations of acute severe brain injuries. Research into their neuroanatomical basis can be traced from Hippocrates to the present day. Lesions causing DoC have traditionally been conceptualized as decreasing "alertness" from damage to the ascending arousal system, and/or, reducing level of "awareness" due to structural or functional impairment of large-scale brain networks. Within this framework, pharmacological and neuromodulatory interventions to promote recovery from DoC have hitherto met with limited success. This is partly due to inter-individual heterogeneity of brain injury patterns, and an incomplete understanding of brain network properties that characterize consciousness. Advances in multiscale computational modelling of brain dynamics have opened a unique opportunity to explore the causal mechanisms of brain activity at the biophysical level. These models can provide a novel approach for selection and optimization of potential interventions by simulation of brain network dynamics individualized for each patient.

Several studies have observed double dissociations in the production of nouns and verbs in persons with aphasia. However, whether or not these dissociations point to grammatical class being a principle of organization in the brain remains contested. Cross-linguistic considerations are important for drawing conclusions in this regard. As such, this study provides the first exploration of Gulf Arabic, a non-concatenative language with complex morphology. Utilizing Bayesian approach, the study tested for dissociations in 8 Gulf Arabic-speaking persons with aphasia (PWA) performance on object and action naming tasks. A double dissociation of nouns and verbs was found across the group, with 4 individuals exhibiting preserved action naming and impaired object naming, while 1 demonstrated the opposite pattern. Further error analysis and theoretical discussion are provided, considering existing explanations for dissociation phenomena in light of our novel findings within the understudied domain of Gulf Arabic aphasia.

This study applies implicit structural priming as a novel treatment for sentence production in persons with aphasia (PWA), investigating the learning mechanism(s) that drive robust and enduring recovery. Sixteen PWA and 16 controls completed baseline, three training sessions, and 1-day and 1-week post-testing. Each participant received both alternating and single structure prime training conditions to test error-based versus repeated activation-based learning. Both groups showed significantly improved production and maintenance of trained and untrained target sentences in both training conditions. While controls showed greater gains following alternating prime structure training, single prime structure training resulted in greater improvements for PWA. These results suggest that structural priming is an effective training for aphasia. Additionally, to the extent that the different priming conditions reflected different mechanisms underlying the learning and access of impaired structure, increased base-level activation of target syntactic structure supports learning of grammatical encoding in aphasia more effectively than processing prime sentences with competing syntactic structures.