Naming in dementia secondary to Parkinson's, Huntington's, and Alzheimer's diseases

Confrontation naming problems have been found in patients with dementia secondary to Alzheimer's (AD), Huntington's (HD), and in a subset of Parkinson's disease (PD) patients with dementia. The source of the naming deficit has not been established. The "Perception" and the "Semantic Feature" theories have been proposed to explain this naming dysfunction. Subjects with dementia secondary to AD, HD, and PD were given three tasks to determine which theory best explained the source of confrontation naming problems. The three tasks including picture matching, visual recognition, and confrontation naming were given to 42 subjects with dementia secondary to AD, HD, and PD controlled for severity of dementia, and to age-matched controls. Subjects with dementia did not have significantly more difficulty matching pictures but did have more difficulty associating pictures through semantic features. Subjects with mild dementia secondary to AD and HD had significantly more confrontation naming errors than subjects with mild dementia secondary to PD and normal controls. All subjects with moderate dementia had significantly more confrontation naming errors than normal controls. Statistical power may have been limited due to the small number of subjects in each group. The source of the reduction in confrontation naming performance in subjects with dementia secondary to AD, HD, and PD originated in the deterioration of semantic fields. The perception theory was rejected as findings were consistent with the semantic feature theory.     

The effect of age of acquisition on speed and accuracy of naming famous faces

Three experiments examined whether famous faces would be affected by the age at which knowledge of the face was first acquired (AoA). Using a multiple regression design, Experiment 1 showed that rated familiarity and AoA were significant predictors of the time required to name pictures of celebrities' faces and the accuracy of producing their names. Experiment 2 replicated an effect of AoA using a factorial design in which other attributes of the celebrities were matched. In both Experiments 1 and 2, several ratings had been collected from participants before naming latency data were collected. Experiment 3 investigated the accuracy and latency of naming celebrities without any prior exposure to the stimuli. An advantage for naming early acquired celebrities was observed even on the first presentation. The participants named the same celebrities in three subsequent presentations of the stimuli. The effect of AoA was not significant on the fourth presentation. The implications of these results for models of face naming and directions for future research are discussed.     

Categorizing chairs and naming pears: category differences in object processing as a function of task and priming

Four experiments are reported examining the locus of structural similarity effects in picture recognition and naming with normal subjects. Subjects carried out superordinate categorization and naming tasks with picture and word forms of clothing, furniture, fruit, and vegetable exemplars. The main findings were as follows: (1) Responses to pictures of fruit and vegetables ("structurally similar" objects) were slowed relative to pictures of clothing and furniture ("structurally dissimilar" objects). This structural similarity difference was greater for picture naming than for superordinate categorization of pictures. (2) Structural similarity effects in picture naming were reduced by repetition priming. Repetition priming effects were equivalent from picture and word naming as prime tasks. (3) However, superordinate categorization of the prime did not produce the structural similarity effects on priming found for picture naming. Furthermore, such priming effects did not arise for picture or word categorization or for reading picture names as target tasks. It is proposed that structural similarity effects on priming object processing are located in processes mapping semantic representations of pictures to name representations required to select names for objects. Visually based competition between fruit and vegetables produces competition in name selection, which is reduced by priming the mappings between semantic and name representations.     

Age of acquisition and word frequency effects in picture naming: A dual-task investigation.

In 2 experiments, the authors explored age of acquisition (AoA) and word frequency (WF) effects in picture naming using the psychological refractory period paradigm. In Experiment 1, participants named a picture and then, a short time later, categorized 1 of 3 possible auditory tones as high, medium, or low. Both AoA (Experiment 1A) and WF (Experiment 1B) effects propagated onto tone discrimination reaction times (RTs), with the effects of AoA being stronger. In Experiment 2, the to-be-named picture followed the auditory tone by a varying interval. As the interval decreased, picture naming RTs increased. The relationship between the interval and AoA (Experiment 2A) was reliably underadditive; AoA effects were eliminated at the shortest interval. In contrast, WF (Experiment 2B) was additive with the effects of the interval. These results demonstrate an empirical dissociation between AoA and WF effects. AoA affects processing stages that precede those that are sensitive to WF. The implications for theories of picture naming are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anomia as a marker of distinct semantic memory impairments in Alzheimer's disease and semantic dementia.

Objective: Many neurologically constrained models of semantic memory have been informed by two primary temporal lobe pathologies: Alzheimer's disease (AD) and Semantic Dementia (SD). However, controversy persists regarding the nature of the semantic impairment associated with these patient populations. Some argue that AD presents as a disconnection syndrome in which linguistic impairment reflects difficulties in lexical or perceptual means of semantic access. In contrast, there is a wider consensus that SD reflects loss of core knowledge that underlies word and object meaning. Object naming provides a window into the integrity of semantic knowledge in these two populations. Method: We examined naming accuracy, errors and the correlation of naming ability with neuropsychological measures (semantic ability, executive functioning, and working memory) in a large sample of patients with AD (n = 36) and SD (n = 21). Results: Naming ability and naming errors differed between groups, as did neuropsychological predictors of naming ability. Despite a similar extent of baseline cognitive impairment, SD patients were more anomic than AD patients. Conclusions: These results add to a growing body of literature supporting a dual impairment to semantic content and active semantic processing in AD, and confirm the fundamental deficit in semantic content in SD. We interpret these findings as supporting of a model of semantic memory premised upon dynamic interactivity between the process and content of conceptual knowledge. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The spectrum of category effects in object and action knowledge in dementia of the Alzheimer's type.

The validity and origin of category effects in the anomia demonstrated by individuals with dementia of the Alzheimer's type (DAT) remains controversial. Twenty DAT subjects were tested with picture naming and semantic association judgement tests. Picture and word stimuli were drawn from biological, nonbiological, and actions–verbs categories, all of equal difficulty and previously normed on elderly controls. DAT subjects made significantly more naming and semantic judgement errors in the biological category than in the nonbiological category. They were relatively more accurate in naming and making judgements for actions–verbs when presented as words or as 5-s animations. When line drawings of actions were shown for naming, performance deteriorated significantly. Converging results from these 2 tasks provide strong evidence for a semantic memory impairment preferentially affecting biological items to a greater extent than nonbiological items or action verbs in DAT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic interference effects on naming using a postcue procedure: Tapping the links between semantics and phonology with pictures and words.

Five experiments are reported in which a new technique for assessing the processes involved in mapping semantic representations onto name information in simple naming tasks was used. This technique, the postcue naming procedure, requires participants to name 1 of 2 potential target stimuli after they receive a relevant selection cue. Naming performance is slowed when the 2 potential targets are semantically related, relative to when they are unrelated. Effects on picture and word targets are of equal magnitude, providing these 2 types of stimulus are intermingled in the experiment. When words are presented alone, semantic interference is abolished (although evidence for lexical processing of words can be demonstrated). The effect on picture naming is also eliminated when the interfering stimulus has to be categorized rather than named. These results suggest that the locus of the interference is in the processes mapping semantic information onto names. These processes seem to be shared by pictures and words when the semantic processing of words is induced. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phonological encoding is not contingent on semantic feature retrieval: An electrophysiological study on object naming.

In the present study, the authors examined with event-related brain potentials whether phonological encoding in picture naming is mediated by basic semantic feature retrieval or proceeds independently. In a manual 2-choice go/no-go task the choice response depended on a semantic classification (animal vs. object) and the execution decision was contingent on a classification of name phonology (vowel vs. consonant). The introduction of a semantic task mixing procedure allowed for selectively manipulating the speed of semantic feature retrieval. Serial and parallel models were tested on the basis of their differential predictions for the effect of this manipulation on the lateralized readiness potential and N200 component. The findings indicate that phonological code retrieval is not strictly contingent on prior basic semantic feature processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic interference, orthographic facilitation, and their interaction in naming tasks.

The relative merits of 3 views on the cause of the Stroop-like semantic interference effect in naming tasks were investigated in 2 experiments. In the 1st experiment, which consisted of a picture-word interference task, the authors found the usual Stroop-like semantic interference effect for distractor words that were not orthographically related to the picture's name. However, the semantic interference effect was significantly reduced when the distractor words were orthographically related to the picture's name. The results were replicated in the 2nd experiment by using a different paradigm in which, instead of pictures, definitions were used as target stimuli. The results are interpreted as favoring one of the views: a word-form retrieval account of the semantic interference effect in naming tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Theories of word naming interact with spelling--sound consistency.

In a previous study (E. Strain, K. Patterson, & M. S. Seidenberg, 1995), the authors concluded that word naming is characterized by an interaction between spelling-sound typicality and word imageability, thus implicating a role for word meaning in the naming process. J. Monaghan and A. W. Ellis (2002) reject E. Strain et al.'s conclusion, arguing that it is age of acquisition (AoA) and not imageability that interacts with spelling-sound typicality. In this article, the authors question their alternative interpretation (a) by raising a number of conceptual and methodological issues germane to this debate and (b) by presenting new data that confirm a significant interaction between spelling-sound typicality and imageability in word-naming latencies, an interaction that is reliable when word AoA is controlled in a regression analysis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Word frequency effects in oral reading are not merely age-of-acquisition effects in disguise.

Four experiments examined the effects of the rated age of acquisition (AoA) and word frequency on oral reading latencies and word pronunciation durations. In Experiment 1, both AoA and frequency had independent (and noninteracting) effects on naming latencies. Experiment 2 found no effect of either AoA or frequency on delayed naming, indicating that prepared articulation time was not a factor contributing to the naming latencies observed in Experiment 1. Experiment 3 reported 2 replications of the study by C. M. Morrison and A. W. Ellis (1995). Both replications found reliable effects of frequency and AoA, whereas Morrison and Ellis found an effect of AoA but no effect of frequency. Experiment 4 found a strong AoA effect on pronunciation durations, with a smaller and less reliable effect of frequency. It was concluded that frequency affects the visual recognition of words and that AoA affects the production of lexical phonology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-of-Acquisition Effects in Word and Picture Identification.

Words and pictures with earlier learned labels are processed faster than words and pictures with later learned labels. This age-of-acquisition (AoA) effect has been extensively investigated in many different types of tasks. This article provides a review of these studies including picture naming, word naming, speeded word naming, word pronunciation durations, lexical decisions, eye fixation times, face recognition, and episodic memory tasks. The measurement and validity of AoA ratings is discussed, along with statistical techniques used for exploring AoA's influence. Finally, theories of AoA are outlined, and evidence for and against the various theories is presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic facilitation with pictures and words.

The present experiments explored the role of processing level and strategic factors in cross-form (word–picture and picture–word) and within-form (picture–picture and word–word) semantic facilitation. Previous studies have produced mixed results. The findings presented in this article indicate that semantic facilitation depends on the task and on the subjects' strategies. When the task required semantic processing of both picture and word targets (e.g., category verification), equivalent facilitation was obtained across all modality combinations. When the task required name processing (e.g., name verification, naming), facilitation was obtained for the picture targets. In contrast, with word targets, facilitation was obtained only when the situation emphasized semantic processing. The results are consistent with models that propose a common semantic representation for both picture and words but that also include assumptions regarding differential order of access to semantic and phonemic features for these stimulus modalities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Verb confrontation naming and word-picture matching in Alzheimer's disease.

Patients with Alzheimer's disease (AD) were asked to name pictures and perform a multiple-choice word–picture matching task with verbs and nouns. AD patients were significantly more impaired with verbs than nouns for both naming and word–picture matching, and their patterns of semantic naming errors differed for verbs and nouns. One subgroup of AD patients was compromised on both naming and word–picture matching consistent with a semantic memory deficit. Naming was worse for verbs than for nouns in these patients, and they produced significantlv fewer hierarchically related semantic substitutions for verbs than for nouns. Other AD patients without semantic memory difficulty did not demonstrate these form class-sensitive patterns. The investigators hypothesize that form class-specific effects in AD patients' naming are due in part to differences in processing verbs and nouns in semantic memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An interactive activation approach to object processing: effects of structural similarity, name frequency, and task in normality and pathology

We present a computational model of the processes involved in retrieving stored semantic and name information from objects, using a simple interactive activation and competition architecture. We simulate evidence showing a cross-over in normal reaction times to make semantic classification and identification responses to objects from categories with either structurally similar or structurally dissimilar exemplars, and that identification times to objects from these two different classes correlate differentially with measures of the structural similarity of objects within the category and the frequency of the object's name. Structural similarity exerts a negative effect on object decision as well as naming, though this effect is larger on naming. Also, on naming, structural similarity interacts with the effects of name frequency, captured in the model by varying the weight on connections from semantic to name units; frequency effects are larger with structurally dissimilar items. In addition, (1) the range of potential errors for objects from these two classes, when responses are elicited before activation reached a stable state, differ--a wider range of errors occur to objects from categories with structurally similar exemplars; and (2) simulated lesions to different locations within the model produce selective impairments to identification but not to semantic classification responses to objects from categories with structurally similar exemplars. We discuss the results in relation to data on visual object processing in both normality and pathology.     

Dissociating word frequency and age of acquisition: The klein effect revived (and reversed).

The Klein effect (G. S. Klein, 1964) refers to the finding that high-frequency words produce greater interference in a color-naming task than low-frequency words. The present study used the Klein effect to investigate the relationship between frequency and age of acquisition (AoA) by measuring their influence on color naming. Two experiments showed reliable effects of frequency (though in the opposite direction to that reported by Klein) but no effects of AoA. Experiment 1 produced a dissociation between frequency and AoA when manipulated orthogonally. Experiment 2 produced the same dissociation using different stimuli. In contrast, both variables reliably influenced word naming. These findings are inconsistent with the view that frequency and AoA are 2 aspects of a single underlying mechanism. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

What exactly interacts with spelling--sound consistency in word naming?

Word frequency, age of acquisition (AoA), and imageability were combined with spelling-sound consistency, and their effects on word naming were examined. Frequency and AoA interacted with consistency (Experiments 1 and 2). Imageability did not (Experiment 3). Experiment 4 replicated Experiment 2 of E. Strain, K. E. Patterson, and M. S. Seidenberg's (1995) study and obtained the same apparent effect of imageability on naming. That effect disappeared when AoA was entered as a covariate. An explanation of the interactions of consistency with frequency and AoA is offered in terms of the properties of adaptive connectionist networks given gradual and cumulative training. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A computational model of naming in Alzheimer's disease: Unitary or multiple impairments?

The predominant explanation for difficulty naming objects in Alzheimer's disease (AD) is impaired semantic memory. Two classes of findings challenge this. The lower the visual quality of the stimulus the less likely AD patients are to name it, suggesting a deficit of visual perception. The lower the name frequency, the less likely AD patients are to name an object, suggesting a deficit of lexical access. A mechanistic explanation is given for why a semantic memory deficit is sufficient to account for this range of data, provided components underlying task performance are interactive. Interactive parallel distributed processing networks were trained to associate visual patterns with semantic and lexical patterns. When semantic units were lesioned, networks were more sensitive to impoverished visual inputs. Networks also made a disproportionate number of errors to items trained with lower frequency and benefited from phonemic cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Standardized stimuli and procedures for investigating the retrieval of lexical and conceptual knowledge for actions

We have developed a set of naming and recognition tests for evaluating the retrieval of lexical and conceptual knowledge for actions. As a first step, normative information about 280 items was collected for the following variables: (1) the naming responses elicited by each item, (2) the degree to which the image of each item agreed with a target name, (3) the familiarity to each depicted action, and (4) the visual complexity of each item. This information was used to develop administration and scoring procedures for a standardized test of action naming. The effectiveness and reliability of these procedures were evaluated in a second experiment. In a third experiment, five tests were developed to probe the retrieval of conceptual knowledge: (1) independently of the production of a naming response, (2) in response to pictorial and nonpictorial stimuli, (3) in terms of the attributes associated with specific actions, and (4) in terms of similarities and differences between various actions.