Conceptual information about size of objects in nouns

Naming as a window to word retrieval changes in healthy and pathological ageing: Methodological considerations

BACKGROUND

Word retrieval skills change across the lifespan. Permanent alterations in the form of decreased accuracy or increased response time can be a consequence of both normal ageing processes or the presence of acquired and neurodegenerative disorders (e.g., aphasia and dementia). Despite the extensive literature exploring the neuroanatomical underpinnings of word retrieval, psycholinguistic, biolinguistic and theoretical explanations, and the vast amount of evidence from primary and secondary language disorders, the best approach to consistently capture these changes is yet to be discovered.

AIMS

The goal of this paper is to determine which method(s) stand(s) as the most suitable candidate(s) to provide an accurate picture of word retrieval in the oral production of different groups of adult speakers, including cases of healthy ageing, preclinical Alzheimer's disease (AD), mild cognitive impairment (MCI), aphasia and dementia.

METHODS & PROCEDURES

Using an integrative review of recent peer-reviewed journal articles, we provide an overview of the different behavioural methods traditionally used to measure oral naming skills in research-oriented and clinical protocols and discuss their main advantages and limitations.

MAIN CONTRIBUTION

Most existing studies are based on the results of people with diagnosed language disorders. Despite the growing interest, the reliability of the majority of the tasks to detect subtle changes associated with healthy ageing, MCI and preclinical AD are yet to be demonstrated, and the delicate balance between informativeness and efficiency (especially in terms of administration time and variable control) in experimental protocols is yet to be achieved. In this article we propose the pursuit of an integrative overarching methodology to characterize all naming deficits (from anecdotal to permanent) and all adult populations (from healthy to pathological ageing).

CONCLUSIONS & IMPLICATIONS

A combination of spontaneous speech data and results from structured tasks stands as the best approach to capture changes in word retrieval skills of adult speakers with and without observable deficits. This review can guide future reflections on the necessary prerequisites of purpose-oriented, sensitive and reliable protocols for the detection of incipient word retrieval problems, thus contributing to the early diagnosis and the design of personalized multicomponent treatments.

WHAT THIS PAPER ADDS

What is already known on this subject Word retrieval skills change during adulthood as a consequence of the neurological degradation associated with ageing. These changes are more dramatic in the event of acquired and neurodegenerative disorders. Numerous studies based on people with observable language disorders have addressed the multiplicity of factors involved in word retrieval and provided evidence of potential loci of impairment from a neuroanatomical, cognitive and/or (psycho-)linguistic perspective. What this paper adds to existing knowledge This study focuses on methodological strategies to assess naming skills and provides a reflection on generally accepted good practices and unresolved challenges to inform task selection, emphasizing the necessity for a combination of methods to best capture the actual problems and needs of people confronting word retrieval difficulties in their daily lives. Task selection, variable control and administration time stand as key concepts to adjust to the requirements of research and clinical contexts. What are the potential or actual clinical implications of this work? The results of this review can orient future research towards the creation of sensitive, reliable and (ecologically) valid materials for the (early) detection of word retrieval deficits and for the customization of treatment protocols to alleviate or palliate their effects.

Processing of Action and Sound Verbs in Context: An FMRI Study

Recent theories propose a flexible recruitment of sensory and motor brain regions during conceptual processing depending on context and task. The present functional magnetic resonance imaging study investigated the influence of context and task on conceptual processing of action and sound verbs. Participants first performed an explicit semantic context decision task, in which action and sound verbs were presented together with a context noun. The same verbs were repeatedly presented in a subsequent implicit lexical decision task together with new action and sound verbs. Thereafter, motor and acoustic localizer tasks were administered to identify brain regions involved in perception and action. During the explicit task, we found differential activations to action and sound verbs near corresponding sensorimotor brain regions. During the implicit lexical decision task, differences between action and sound verbs were absent. However, feature-specific repetition effects were observed near corresponding sensorimotor brain regions. The present results suggest flexible conceptual representations depending on context and task. Feature-specific effects were observed only near, but not within corresponding sensorimotor brain regions, as defined by the localizer tasks. Our results therefore only provide limited evidence in favor of grounded cognition theories assuming a close link between the conceptual and the sensorimotor systems.

Visual and Imagery Magnitude Comparisons Are Affected Following Left Parietal Lesion

We describe Jane Dow (JD), a young right-handed female with acalculia following a cerebral infarction in the left intraparietal sulcus. We investigated automatic processing of different types of magnitudes that were presented visually or through imagery. We employed the size congruity task and the mental clock task that differ in stimuli presentation and in working memory load. In the size congruity task, for physical comparisons, JD presented a lack of facilitation effect, suggesting a deficit in the automatic processing of numerical values. In the mental clock task, JD performed as accurate as controls did but much slower. In both tasks, JD presented a steeper distance effect compared to controls, suggesting a deficit in a domain-general comparison process. Our findings present an atypical pattern of magnitude processing following a left parietal lesion that appears not only for visually presented stimuli but also for imagery-based magnitudes. These finding support recent theories suggesting different types of magnitudes are interconnected with each other.

Remembering that big things sound big: Sound symbolism and associative memory

According to sound symbolism theory, individual sounds or clusters of sounds can convey meaning. To examine the role of sound symbolic effects on processing and memory for nonwords, we developed a novel set of 100 nonwords to convey largeness (nonwords containing plosive consonants and back vowels) and smallness (nonwords containing fricative consonants and front vowels). In Experiments 1A and 1B, participants rated the size of the 100 nonwords and provided definitions to them as if they were products. Nonwords composed of fricative/front vowels were rated as smaller than those composed of plosive/back vowels. In Experiment 2, participants studied sound symbolic congruent and incongruent nonword and participant-generated definition pairings. Definitions paired with nonwords that matched the size and participant-generated meanings were recalled better than those that did not match. When the participant-generated definitions were re-paired with other nonwords, this mnemonic advantage was reduced, although still reliable. In a final free association study, the possibility that plosive/back vowel and fricative/front vowel nonwords elicit sound symbolic size effects due to mediation from word neighbors was ruled out. Together, these results suggest that definitions that are sound symbolically congruent with a nonword are more memorable than incongruent definition-nonword pairings. This work has implications for the creation of brand names and how to create brand names that not only convey desired product characteristics, but also are memorable for consumers.

Feature-Specific Event-Related Potential Effects to Action- and Sound-Related Verbs during Visual Word Recognition

Grounded cognition theories suggest that conceptual representations essentially depend on modality-specific sensory and motor systems. Feature-specific brain activation across different feature types such as action or audition has been intensively investigated in nouns, while feature-specific conceptual category differences in verbs mainly focused on body part specific effects. The present work aimed at assessing whether feature-specific event-related potential (ERP) differences between action and sound concepts, as previously observed in nouns, can also be found within the word class of verbs. In Experiment 1, participants were visually presented with carefully matched sound and action verbs within a lexical decision task, which provides implicit access to word meaning and minimizes strategic access to semantic word features. Experiment 2 tested whether pre-activating the verb concept in a context phase, in which the verb is presented with a related context noun, modulates subsequent feature-specific action vs. sound verb processing within the lexical decision task. In Experiment 1, ERP analyses revealed a differential ERP polarity pattern for action and sound verbs at parietal and central electrodes similar to previous results in nouns. Pre-activation of the meaning of verbs in the preceding context phase in Experiment 2 resulted in a polarity-reversal of feature-specific ERP effects in the lexical decision task compared with Experiment 1. This parallels analogous earlier findings for primed action and sound related nouns. In line with grounded cognitions theories, our ERP study provides evidence for a differential processing of action and sound verbs similar to earlier observation for concrete nouns. Although the localizational value of ERPs must be viewed with caution, our results indicate that the meaning of verbs is linked to different neural circuits depending on conceptual feature relevance.

Automaticity of Conceptual Magnitude

What is bigger, an elephant or a mouse? This question can be answered without seeing the two animals, since these objects elicit conceptual magnitude. How is an object's conceptual magnitude processed? It was suggested that conceptual magnitude is automatically processed; namely, irrelevant conceptual magnitude can affect performance when comparing physical magnitudes. The current study further examined this question and aimed to expand the understanding of automaticity of conceptual magnitude. Two different objects were presented and participants were asked to decide which object was larger on the screen (physical magnitude) or in the real world (conceptual magnitude), in separate blocks. By creating congruent (the conceptually larger object was physically larger) and incongruent (the conceptually larger object was physically smaller) pairs of stimuli it was possible to examine the automatic processing of each magnitude. A significant congruity effect was found for both magnitudes. Furthermore, quartile analysis revealed that the congruity was affected similarly by processing time for both magnitudes. These results suggest that the processing of conceptual and physical magnitudes is automatic to the same extent. The results support recent theories suggested that different types of magnitude processing and representation share the same core system.

A functional role for modality-specific perceptual systems in conceptual representations

Theories of embodied cognition suggest that conceptual processing relies on the same neural resources that are utilized for perception and action. Evidence for these perceptual simulations comes from neuroimaging and behavioural research, such as demonstrations of somatotopic motor cortex activations following the presentation of action-related words, or facilitation of grasp responses following presentation of object names. However, the interpretation of such effects has been called into question by suggestions that neural activation in modality-specific sensorimotor regions may be epiphenomenal, and merely the result of spreading activations from “disembodied”, abstracted, symbolic representations. Here, we present two studies that focus on the perceptual modalities of touch and proprioception. We show that in a timed object-comparison task, concurrent tactile or proprioceptive stimulation to the hands facilitates conceptual processing relative to control stimulation. This facilitation occurs only for small, manipulable objects, where tactile and proprioceptive information form part of the multimodal perceptual experience of interacting with such objects, but facilitation is not observed for large, nonmanipulable objects where such perceptual information is uninformative. Importantly, these facilitation effects are independent of motor and action planning, and indicate that modality-specific perceptual information plays a functionally constitutive role in our mental representations of objects, which supports embodied assumptions that concepts are grounded in the same neural systems that govern perception and action.