Action naming with impaired semantics: Neuropsychological evidencecontrasting naming and reading for objects and verbs

We contrast naming from pictures, and reading words, for objects and verbs (actions relating to the objects) in a patient with a large, posterior left-hemisphere lesion. We present evidence for spared picture naming for verbs relative to objects, whilst the opposite pattern of sparing occurred in reading. Objects were also spared relative to verbs in tasks requiring that written words be matched to either pictures or auditory words, in the presence of semantically related or unrelated distractors. We conclude that verb semantics were more impaired than semantic knowledge for objects, and that the better semantic knowledge for object names supported word reading. With pictures, however, action verb retrieval was maintained through a nonsemantic route from vision to action, or though preserved right-hemisphere “action semantics.”     

Regions of neural dysfunction associated with impaired naming of actions and objects in acute stroke

The proposal that there are distinct neural regions devoted to the representation or processing of names of objects versus actions has received support from a variety of sources. However, there have been conflicting results regarding the localisation of the postulated mechanisms that are more crucial for one category or the other. There is also controversy as to whether the separation of mechanisms devoted to object versus action naming arises at the level of lexical-semantics or at the level of accessing lexical representations for output. We addressed these issues by testing oral naming and word comprehension of object and action names in 33 right-handed patients with acute left-hemisphere stroke, and by obtaining magnetic resonance (MR) perfusion-weighted and diffusion-weighted imaging of each patient at the same time. We identified regions of abnormal blood flow or infarction associated with impaired naming (with and without impaired word comprehension) of objects, of actions, or of both, using Fisher Exact tests. We found both neural regions shared by networks underlying naming of actions and networks underlying naming of objects, and other neural regions that were crucial to only one network or the other. One of the shared components (in the left superior temporal gyrus) was also essential to comprehension of action and object names (as tested by word/picture verification). These results converge with evidence from chronic lesion studies and functional imaging studies, indicating that some components of the neural networks for accessing lexical representations for output are more important for object names (e.g., left temporal cortex) and others more important for action names (e.g., left posterior frontal cortex).     

Regions of neural dysfunction associated with impaired naming of actions and objects in acute stroke

The proposal that there are distinct neural regions devoted to the representation or processing of names of objects versus actions has received support from a variety of sources. However, there have been conflicting results regarding the localisation of the postulated mechanisms that are more crucial for one category or the other. There is also controversy as to whether the separation of mechanisms devoted to object versus action naming arises at the level of lexical-semantics or at the level of accessing lexical representations for output. We addressed these issues by testing oral naming and word comprehension of object and action names in 33 right-handed patients with acute left-hemisphere stroke, and by obtaining magnetic resonance (MR) perfusion-weighted and diffusion-weighted imaging of each patient at the same time. We identified regions of abnormal blood flow or infarction associated with impaired naming (with and without impaired word comprehension) of objects, of actions, or of both, using Fisher Exact tests. We found both neural regions shared by networks underlying naming of actions and networks underlying naming of objects, and other neural regions that were crucial to only one network or the other. One of the shared components (in the left superior temporal gyrus) was also essential to comprehension of action and object names (as tested by word/picture verification). These results converge with evidence from chronic lesion studies and functional imaging studies, indicating that some components of the neural networks for accessing lexical representations for output are more important for object names (e.g., left temporal cortex) and others more important for action names (e.g., left posterior frontal cortex).     

Naming a giraffe but not an animal: Base-level but not superordinate naming in a patient with impaired semantics

We report data on patient FK, who presented with a marked deficit in accessing semantic knowledge about objects when tested across a range of input and output modalities. FK also showed a high degree of item-specific consistency in object identification, over and above effects due to object familiarity. We show that, despite being better at naming some objects than others, FK was equally poor at discriminating the superordinate categories of the stimuli. Also, he tended to be better at matching nameable items to a base-level label than to a superordinate-level label. We discuss the implications of the data for models of semantic memory.     

Naming a giraffe but not an animal: Base-level but not superordinate naming in a patient with impaired semantics

We report data on patient FK, who presented with a marked deficit in accessing semantic knowledge about objects when tested across a range of input and output modalities. FK also showed a high degree of item-specific consistency in object identification, over and above effects due to object familiarity. We show that, despite being better at naming some objects than others, FK was equally poor at discriminating the superordinate categories of the stimuli. Also, he tended to be better at matching nameable items to a base-level label than to a superordinate-level label. We discuss the implications of the data for models of semantic memory.     

Length effect in word naming in reading: role of reading experience and reading deficit in italian readers

Vocal reaction times (RTs) in naming 3- to 8-letter words were measured in proficient and dyslexic readers (Study 1). In proficient readers, RTs were independent of word length up to 5-letter words, indicating parallel processing. In the 5- to 8-letter range, RTs increased linearly, indicating sequential processing. Reading experience was associated with both faster discrimination of individual elements and parallel processing of increasingly large word parts. In dyslexics, RTs increased linearly with increasing length indicating reliance on sequential decoding. Individual analysis indicated 2 profiles of RTs (Types A and B). In Study 2, the distinction between A and B dyslexics was not associated with the use of different reading procedures. However, a more marked speed deficit characterized Type B dyslexics.     

Beginning reading without semantics: a cognitive study of hyperlexia

Literacy development in MP, a hyperlexic boy, was followed over his first three school years in a longitudinal case study. The other members of his class, who received the same programme of instruction, provided a reference group. Despite impaired language production and comprehension, MP developed an effective orthographic system, indexed by normal reactiontime patterns and success in reading (and spelling) words and nonwords. Semantic processing of single lexical items also appeared efficient. The results are taken to imply the “developmental modularity” of the orthographic and (propositional) semantic system.     

Neuropsychological profiles of children diagnosed as specific language impaired with and without hyperlexia.

This study compared the neuropsychological profiles of 46 children with Specific Language Impairment (SLI) and 16 children with SLI and Hyperlexia (SLI + H). The results indicated that the essential feature of Hyperlexia is Specific Language Impairment and not reading disability. Thus, Hyperlexia would be best conceptualized as a subgroup of Developmental Language Disorder rather than as a subgroup of Developmental Dyslexia. Further, the SLI + H group exhibited significantly better developed visual/spatial memory which, along with average visual perceptual skills, appears to be the major contributing factor to their elevated word recognition and spelling ability. Finally, it should be noted that both groups of children exhibited decreasing performance on tasks of immediate auditory/verbal memory as the language/semantic demands of the memory task increased. This finding appears to be the result of a limited capacity for immediate verbal processing and not the result of a deficit in verbal learning and recall.     

Nouns, verbs, objects, actions, and the animate/inanimate effect

We report an aphasic patient, Z.B.L., who showed a significant advantage for verbs compared to nouns in picture-naming tests. Within the object class, he performed better on animate things than on nonliving things in picture naming as well as in an "attribute judgement task". This pattern of performance is contrary to the central prediction of a recent proposal (Bird, Howard, & Franklin, 2000), which attributes noun-verb dissociation in aphasic patients to deficits in processing certain kinds of semantic features. This model proposes that conceptual representations of verbs have a lower proportion of sensory features than do representations of nouns; the same is proposed for inanimate versus animate items within the noun category. Noun deficits are assumed to arise due to impairment for the processing of sensory features. The model predicts that if a patient is more impaired for nouns than for verbs, he will also display more difficulty with animate than with inanimate objects. Contrary to predications derived from this theory, Z.B.L. performed better with animate than inanimate nouns.     

Nouns,verbs, objects,actions, and the animate/inanimate effect

We report an aphasic patient, Z.B.L., who showed a significant advantage for verbs compared to nouns in picture-naming tests. Within the object class, he performed better on animate things than on nonliving things in picture naming as well as in an “attribute judgement task”. This pattern of performance is contrary to the central prediction of a recent proposal (Bird, Howard, & Franklin, 2000 Bird, H., Howard, D. and Franklin, S. 2000. Why is a verb like an inanimate object? Grammatical category and semantic category deficits. Brain and Language, 72: 246–309. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]), which attributes noun–verb dissociation in aphasic patients to deficits in processing certain kinds of semantic features. This model proposes that conceptual representations of verbs have a lower proportion of sensory features than do representations of nouns; the same is proposed for inanimate versus animate items within the noun category. Noun deficits are assumed to arise due to impairment for the processing of sensory features. The model predicts that if a patient is more impaired for nouns than for verbs, he will also display more difficulty with animate than with inanimate objects. Contrary to predications derived from this theory, Z.B.L. performed better with animate than inanimate nouns.     

Prefrontal and parietal regions are involved in naming of objects seen from unusual viewpoints

Object naming is commonly used for demonstrating semantic memory abilities, known to be affected in normal aging. Yet, neuropsychological assessments of older people do not reflect irregularities. The authors used a test with 2 levels of naming complexity by 2 kinds of stimuli: common objects pictured from a conventional viewpoint (usual condition) or from an unconventional viewpoint (unusual condition). The authors studied naming performance with 129 healthy participants, aged 20-85 years. For the usual stimuli, the success rate was high (90.9%), with no reduction in performance until 65 years of age. However, for the unusual stimuli, there was a marked reduction in performance with age. Brain activity was studied on 11 healthy young participants (20-30 years of age) using functional magnetic resonance imaging. The usual condition activated brain regions associated with visual perception, language, and memory. Additional brain regions associated with semantic searching and decision making were obtained in the unusual condition in the prefrontal cortex (Brodmann's area [BA] 9 and BA 47) and anterior cingulate (BA 32). The results suggest that the poor naming performance for unusual-viewed objects in older people might be related to the shrinkage of frontal gray matter with age.     

An fMRI study of Chinese character reading and picture naming by native Korean speakers

Chinese characters appear in the currently used Korean language, and the system used for writing system the Korean language consists of a mixture of the Korean alphabet and Chinese characters. In the present study, neural mechanisms involved in reading a single Chinese character words and naming pictures by Korean native speakers were investigated using a functional magnetic resonance imaging technique. The findings show a right hemispheric dominance within the occipito-temporal and the left middle/medial frontal area for both reading Chinese characters and naming pictures. This should reflect the specific visual processing of reading Chinese characters. Additional activations in inferior frontal and cingulage gyrus were also observed. The activations of inferior parietal region and thalamus are of interest, since we assume that these activations are strongly related to the phonological status of single Chinese character words rather than two character words that are typically used by Korean native speakers.     

Acquired prosopagnosia with spared within-class object recognition but impaired recognition of degraded basic-level objects

We present a new case of acquired prosopagnosia resulting from extensive lesions predominantly in the right occipitotemporal cortex. Functional brain imaging revealed atypical activation of all core face areas in the right hemisphere, with reduced signal difference between faces and objects compared to controls. In contrast, Herschel's lateral occipital complex showed normal activation to objects. Behaviourally, Herschel is severely impaired with the recognition of familiar faces, discrimination between unfamiliar identities, and the perception of facial expression and gender. Notably, his visual recognition deficits are largely restricted to faces, suggesting that the damaged mechanisms are face-specific. He showed normal recognition memory for a wide variety of object classes in several paradigms, normal ability to discriminate between highly similar items within a novel object category, and intact ability to name basic objects (except four-legged animals). Furthermore, Herschel displayed a normal face composite effect and typical global advantage and global interference effects in the Navon task, suggesting spared integration of both face and nonface information. Nevertheless, he failed visual closure tests requiring recognition of basic objects from degraded images. This abnormality in basic object recognition is at odds with his spared within-class recognition and presents a challenge to hierarchical models of object perception.     

Action and object naming in frontotemporal dementia, progressive supranuclear palsy, and corticobasal degeneration

Action naming has been reported to be disproportionately impaired in comparison to object naming in patients with frontotemporal dementia (FTD). This finding has been attributed to the crucial role of frontal cortex in action naming. The investigation of object and action naming in the different subtypes of FTD, as well as in the related conditions of progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD), may thus contribute to the elucidation of the cerebral correlates of the action-object discrepancy as well as provide clues to the underlying cognitive mechanisms. The results indicated that, with the exception of semantic dementia, action naming was more impaired than object naming in all patient groups. The discrepancy was similar in frontal variant of FTD and Alzheimer's disease patients, whereas patients with nonfluent primary progressive aphasia, PSP, and CBD were significantly more impaired in the oral production of actions than of objects. These findings indicate that action naming impairment is not a general feature of FTD, but rather is associated with conditions that affect the frontoparietal-subcortical circuits involved in action knowledge and action representation.     

Neuropsychological analyses of comorbidity between reading disability and attention deficit hyperactivity disorder: in search of the common deficit

Measures of component reading and language skills, executive functions, and processing speed were administered to groups of children with attention deficit hyperactivity disorder (ADHD; n = 113), reading disability (RD; n = 109), both RD and ADHD (n = 64), and neither RD nor ADHD (n = 151). Groups with RD exhibited pronounced deficits on all measures of component reading and language skills, as well as significant weaknesses on measures of verbal working memory, processing speed, and response inhibition. Groups with ADHD exhibited weaknesses on all response-inhibition and processing speed tasks and were impaired on some measures of component reading skills and verbal working memory. The group with comorbid RD and ADHD exhibited the combination of the deficits in the RD-only and ADHD-only groups, providing evidence against the phenocopy and cognitive subtype hypotheses as explanations for the co-occurrence of RD and ADHD. Slow and variable processing speed was characteristic of all 3 clinical groups, suggesting that measures of this domain may be useful for future studies that search for the common genes that increase susceptibility to RD and ADHD.     

Action semantics and movement characteristics engage distinct processing streams during the observation of tool use

The cortical motor system follows a modular organization in which different features of executed movements are supported by distinct streams. Accordingly, different levels of action recognition, such as movement characteristics or action semantics may be processed within distinct networks. The present study aimed to differentiate areas related to the analysis of action features involving semantic knowledge from regions concerned with the evaluation of movement characteristics determined by structural object properties. To this end, the assessment of (i) tool-associated actions in relation to semantically, but not functionally inappropriate recipients (factor “Semantics”), and the evaluation of (ii) tool-associated movements performed with awkward versus correct hand postures (factor “Hand”) were experimentally manipulated in an fMRI study with an event-related 2 × 2 factorial design. The videos used as stimuli displayed actions performed with the right hand in third-person perspective. Conjunction analysis of all four experimental conditions showed that observing videos depicting tool-related actions compared to rest was associated with widespread bilateral activity within the frontal lobes, inferior and superior parietal lobules, parts of the temporal lobes, as well as the occipital lobes. Viewing actions executed with incorrect compared to correct hand postures (factor “Hand”) elicited significantly more activity within right primary sensory cortex (Brodmann area 2) and superior parietal lobule. Conversely, tool-associated actions displayed after semantically incorrect compared to correct recipients elicited higher activation within a left-lateralized network comprising the ventro-lateral prefrontal cortex (VLPFC), parts of the intraparietal sulcus and the angular gyrus (AG), as well as the supplementary motor area (SMA) and pre-SMA. Probabilistic diffusion tensor imaging-based tractography revealed two distinct fiber connections between AG and the frontal activation: A dorsal pathway via the superior longitudinal fascicle to the caudal part of VLPFC and a ventral pathway reaching the more rostral parts of VLPFC via the extreme capsule. The task-dependent relative modulation of activity within these brain networks composed of activated cortical areas connected by specific white matter tracts may indicate that the assessment of semantic action features relies on both dorso-ventral and ventral processing streams, whereas the analysis of hand postures with respect to objects depends on areas within the dorso-dorsal stream.     

Embodied representation of tool-use action verbs and hand action verbs: evidence from a tone judgment task

Many studies have found that language comprehension involves sensory-motor system. However, the relationship between word form and embodied semantic representation still lacks evidence. The current fMRI study used Chinese tool-use action verbs, hand action verbs and a Mandarin lexical tone task to explore the issue. In the tone task, all verbs showed strong effects in hand motor areas. However, the contrasts between the hand action verbs and the tool-use action verbs yielded differences mainly in tone processing areas, and the hand action verbs had stronger effects. The ROI analyses indicated consistent result pattern with the contrast analyses. In short, these results revealed that word processing involves basic sensory-motor information automatically, whereas the fine grained information which distinguishes among different semantics can be hindered by the processing of word form.