Recency discrimination deficits in frontal lobe patients.

Damage to the frontal lobes appears to cause a deficit in the temporal organization of memory. M. P. McAndrews and B. Milner (see record 1992-16996-001) found that S-performed tasks (SPTs), which involve the performance of actions with common objects, allowed frontal-lobe-damaged patients to circumvent this deficit and perform normally on recency judgments. The present investigation of the critical properties of SPTs compared the performance of frontal-lobe-damaged patients and healthy controls on recency judgments under 5 encoding conditions: SPT, naming, visual imagery, experimenter-performed tasks, and verbal elaboration. Patients' performance varied across encoding conditions, but controls' did not. Post hoc comparisons confirmed that patients performed significantly worse than controls across all encoding tasks except SPT. The findings help elucidate the nature of both SPTs and memory for temporal order. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Superadditive effects of multiple lesions in a connectionist architecture: Implications for the neuropsychology of optic aphasia.

Neuropsychological disorders have traditionally been understood in terms of a focal lesion to a single component of a cognitive architecture. Optic aphasia (OA) defies explanation in this way. In OA, naming of visual stimuli is impaired in the absence of general visual agnosia or anomia. OA has been explained by positing multiple semantic systems or multiple functional pathways to visual naming. M. J. Farah (1990) instead sketched a parsimonious account based on multiple lesions—to pathways mapping visual input to semantics and semantics to naming responses—and the assumption that the effects of the lesions are superadditive. The authors demonstrate superadditive effects of damage in a connectionist architecture and model other phenomena associated with OA. Multiple lesions with superadditivity provide a novel class of explanations for neuropsychological deficits that previously seemed to imply the existence of highly specialized processing components. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The cognitive profile and multiple-deficit hypothesis in Chinese developmental dyslexia.

The present study was conducted to examine the cognitive profile and multiple-deficit hypothesis in Chinese developmental dyslexia. Thirty Chinese dyslexic children in Hong Kong were compared with 30 average readers of the same chronological age (CA controls) and 30 average readers of the same reading level (RL controls) in a number of rapid naming, visual, phonological, and orthographic tasks. Chinese dyslexic children performed significantly worse than the CA controls but similarly to the RL controls on most of the cognitive tasks. The rapid naming deficit was found to be the most dominant type of cognitive deficit in Chinese dyslexic children. Over half of the dyslexic children exhibited deficits in 3 or more cognitive areas, and there was a significant association between the number of cognitive deficits and the degree of reading and spelling impairment. The present findings support the multiple-deficit hypothesis in Chinese developmental dyslexia. (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)     

Processing across the language boundary: A cross-modal priming study of Spanish-English bilinguals.

A cross-modal naming paradigm was used to assess within- and between-language sentential priming in Spanish-English bilinguals. The paradigm used single-language auditory texts with visual target words under normal, visually degraded, speeded, and delayed naming conditions. Cross-language priming was always observed when the target language was predictable (in the blocked condition), even under speeded conditions. When the target language was unpredictable (in the mixed condition), cross-language priming was observed only when response was delayed (delayed naming) and under a subset of conditions when word recognition was delayed (visual degradation). Results are compatible with the idea that cross-language priming in a sentence context is more likely to involve the use of expectations, strategic processes, or both that allow bilinguals to tune themselves to external conditions. There are enough exceptions to the general rule, however, to warrant a reconsideration of the lexical-postlexical dichotomy. Implications for modular versus interactive models of lexical access are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic and phonological codes interact in single word production.

The relationship between semantic–syntactic and phonological levels in speaking was investigated using a picture naming procedure with simultaneously presented visual or auditory distractor words. Previous results with auditory distractors have been used to support the independent stage model (e.g., H. Schriefers, A. S. Meyer, & W. J. M. Levelt, 1990), whereas results with visual distractors have been used to support an interactive view (e.g., P. A. Starreveld & W. La Heij, 1996). Experiment 1 demonstrated that with auditory distractors, semantic effects preceded phonological effects, whereas the reverse pattern held for visual distractors. Experiment 2 indicated that the results for visual distractors followed the auditory pattern when distractor presentation time was limited. Experiment 3 demonstrated an interaction between phonological and semantic relatedness of distractors for auditory presentation, supporting an interactive account of lexical access in speaking. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A prospective evaluation of a diffractive versus a refractive designed multifocal intraocular lens

OBJECTIVE: To evaluate prospectively a diffractive (811E, Pharmacia; power add +4.0 D) versus a refractive (PA154N, Allergan; power add +3.5 D) designed multifocal lens. PARTICIPANTS: Eighty patients planned for cataract surgery without additional ocular pathologies were randomized into the diffractive or refractive group, respectively. INTERVENTION: A standardized no-stitch phacoemulsification with implantation of one of the two multifocal lenses was performed in each patient. MAIN OUTCOME MEASURES: Distance and near-visual acuity, contrast sensitivity, low contrast visual acuity, glare visual acuity, and depth of focus were measured after surgery. RESULTS: All treated patients had best-corrected visual acuities of 20/30 or better. Near-uncorrected vision was significantly better (P < 0.0001) with the diffractive lens (mean, J1) than with the refractive lens (mean, J4). Low contrast visual acuity (61 +/- 12% versus 59 +/- 9%), glare visual acuity (39 +/- 19% versus 38 +/- 14%), and contrast sensitivity (1.48 +/- 0.08 versus 1.50 +/- 0.12) were not significantly different between the groups. CONCLUSIONS: Both lens designs showed satisfactory functional results with advantages for the diffractive lens design.     

The production of specific and generic associates of living and nonliving, high- and low-familiarity stimuli in Alzheimer's disease

The goal of this paper was to address three issues relevant to the semantic-lexical deficit of Alzheimer's disease (AD) patients: (1) the nature of the deficit (contrasting the loss of information with the difficulty of intentional access hypothesis), (2) stimulus familiarity effects, (3) semantic category effects (contrasting living with nonliving categories). Sixteen patients affected by AD and 11 matched control subjects were given a naming task, a word-picture matching task and a generative associative naming task, constructed by using as stimuli the same 40 items. Stimuli were either living or nonliving items of high, medium, and low familiarity. Responses given on the generative associative naming task were classified as generic (poorly informative) or specific (more informative). As expected, AD patients were poorer than controls both in naming and in word-to-picture matching tasks. In the generative associative naming task, AD patients tended to produce fewer specific than generic associations with respect to controls. Category effects had a significant influence on performance only on the naming task, but not on the word-to-picture matching or on the generative associative naming task. Stimulus familiarity, on the other hand, strongly influenced performance both in AD patients and in controls: naming and comprehension were better for high familiarity items with respect to low familiarity items. For generative associative naming, the tendency of AD patients to produce fewer specific than generic associations was mainly significant for low familiarity items.     

The double-deficit hypothesis for the developmental dyslexias.

The authors propose an alternative conceptualization of the developmental dyslexias, the double-deficit hypothesis (i.e., phonological deficits and processes underlying naming-speed deficits represent 2 separable sources of reading dysfunction). Data from cross-sectional, longitudinal, and cross-linguistic studies are reviewed supporting the presence of 2 single-deficit subtypes with more limited reading impairments and 1 double-deficit subtype with more pervasive and severe impairments. Naming-speed and phonological-awareness variables contribute uniquely to different aspects of reading according to this conception, with a model of visual letter naming illustrating both the multicomponential nature of naming speed and why naming speed should not be subsumed under phonological processes. Two hypotheses concerning relationships between naming-speed processes and reading are considered. The implications of processing speed as a second core deficit in dyslexia are described for diagnosis and intervention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Olfactory prodromal symptoms and unilateral olfactory dysfunction are associated in patients with right mesial temporal lobe epilepsy

PURPOSE: We report a patient with mesial temporal lobe epilepsy (MTLE) with olfactory prodromal symptoms manifested as an unpleasant smell of onions, who was found to have an ipsilateral deficit of olfactory naming (olfactory agnosia). METHODS AND RESULTS: Preoperative olfactory testing revealed a selective right-sided olfactory deficit for naming of odors. Olfactory threshold was within the normal range. The patient has been seizure free after selective amygdalohippocampectomy for 4 months. No olfactory prodromal events have occurred since surgery. Olfactory testing 3 months after resection showed that right-sided odor naming was still impaired. CONCLUSIONS: We conclude that olfactory prodromal symptoms may be associated with unilateral olfactory dysfunction, and lateralization of seizure origin may be possible by unilateral olfactory testing.     

Verbal fluency deficits in Parkinson's disease.

Administered verbal (category naming, letter fluency) and nonverbal (category drawing, design fluency) tasks to patients with Parkinson's disease (PD). PD patients were significantly impaired only in their category naming for a semantic target like fruit. The hypothesis that compromised lexical retrieval contributed to PD patients' impaired category naming by examining free recall and recognition on a supraspan learning task was tested. PD patients were significantly impaired in free recall but not recognition. Category naming fluency correlated with free recall but not recognition on the supraspan learning task. It is argued that the verbal fluency deficit in PD is due to a lexical retrieval impairment and that the difference between category naming and letter fluency is due to the nature of the prompts for lexical retrieval that patients can derive from these tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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.     

Age-related deficits in auditory confrontation naming.

The naming of manipulable objects in older and younger adults was evaluated across auditory, visual, and multisensory conditions. Older adults were less accurate and slower in naming across conditions, and all subjects were more impaired and slower to name action sounds than pictures or audiovisual combinations. Moreover, there was a sensory by age group interaction, revealing lower accuracy and increased latencies in auditory naming for older adults unrelated to hearing insensitivity but modest improvement to multisensory cues. These findings support age-related deficits in object action naming and suggest that auditory confrontation naming may be more sensitive than visual naming. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociable mechanisms of subitizing and counting: Neuropsychological evidence from simultanagnosic patients.

Do people have to count to determine visual numerosity, or is there a fast "subitizing" procedure dedicated to small sets of 1 to 3 items? Numerosity naming time and errors were measured in 5 simultanagnosic patients who suffered from severe difficulties in serial counting. Although these patients made close to 100% errors in quantifying sets comprising more than 3 items, they were excellent at quantifying sets of 1, 2, and sometimes 3 items. Their performances in visual search tasks suggested that they suffered from a deficit of serial visual exploration, due to a fundamental inability to use spatial tags to keep track of previously explored locations. The present data suggest that the patients' preserved subitizing abilities were based not on serial processing but rather on a parallel algorithm dedicated to small numerosities. Several ways in which this parallel subitizing algorithm might function are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive neuropsychological analysis and neuroanatomic correlates in a case of acute anomia

We describe an analysis of lexical processing performed in a patient with the acute onset of an isolated anomia. Based on a model of lexical processing, we evaluated hypotheses as to the source of the naming deficit. We observed impairments in oral and written picture naming and oral naming to definition with relatively intact semantic processing across input modalities, suggesting that output from the semantic system was impaired. In contrast to previous reports, we propose that this pattern represents an impairment that arises late in semantic processing prior to accessing mode-specific verbal and graphemic output lexicons. These deficits were associated with a lesion in the posterior portion of the middle temporal gyrus or area 37, an area of supramodal association cortex that is uniquely suited as a substrate for the multimodal deficit in naming.     

Word naming and memory load: Still searching for an individual differences explanation.

S. E. Bernstein and T. H. Carr (1996) and P. M. Pexman and S. J. Lupker (1995) suggested that classifiable individual differences in word-naming performance can account for the varied findings on the naming and memory load task (NMLT; K. R. Paap and R. W. Noel, 1991). Bernstein and Carr's technique of testing their explanation by using performance on part of the NMLT to classify participants is problematic, however. To remedy this, in the present study participants were classified on the basis of performance on a priori tasks: Participants completed a naming task, a naming task with low memory load, and the NMLT. Performance on the NMLT was not predicted by performance on either a priori task, thus providing no support for either Bernstein and Carr's or Pexman and Lupker's individual differences accounts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Divergent trajectories in the aging mind: Changes in working memory for affective versus visual information with age.

Working memory mediates the short-term maintenance of information. Virtually all empirical research on working memory involves investigations of working memory for verbal and visual information. Whereas aging is typically associated with a deficit in working memory for these types of information, recent findings suggestive of relatively well-preserved long-term memory for emotional information in older adults raise questions about working memory for emotional material. This study examined age differences in working memory for emotional versus visual information. Findings demonstrate that, despite an age-related deficit for the latter, working memory for emotion was unimpaired. Further, older adults exhibited superior performance on positive relative to negative emotion trials, whereas their younger counterparts exhibited the opposite pattern. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The more you know the less you can tell: inhibitory effects of visuo-semantic activation on modality specific visual misnaming

WH, a 77-years old right-handed psychoanalyst, displayed modality specific visual misnaming as a sequel of an embolic stroke in the left posterior cerebral artery. WH's errors in visual object naming consisted mainly of semantic paraphasias and perseverations. His verbalizations during testing sometimes manifested a conflict between correct responses and perseverations. Analysis of the stream of information from visual perception via semantics to phonology suggested incomplete access from vision to semantics as the source of errors. The disconnection did not affect verbo-visual matching, though he was unable to reject names that did not correspond to visual stimuli. Action naming was relatively spared, but naming of pictures of actions with objects was worse than naming of pictures of intransitive actions. Tactile naming worsened with simultaneous vision of objects. In visual object naming the error rate increased with increasing familiarity of objects. We propose that an interaction of excitation and inhibition within a single semantic system can explain the clinical phenomena of modality specific visual misnaming.     

Recognition by action: dissociating visual and semantic routes to action in normal observers

In this article the operation of a direct visual route to action in response to objects, in addition to a semantically mediated route, is demonstrated. Four experiments were conducted in which participants made gesturing or naming responses to pictures under deadline conditions. There was a cross-over interaction in the number of visual errors relative to the number of semantic plus semantic-visual errors in the two tasks: In gesturing, compared with naming, participants made higher proportions of visual errors and lower proportions of semantic plus semantic-visual errors (Experiments 1, 3, and 4). These results suggest that naming and gesturing are dependent on separate information-processing routes from stimulus to response, with gesturing dependent on a visual route in addition to a semantic route. Partial activation of competing responses from the visual information present in objects (mediated by the visual route to action) leads to high proportions of visual errors under deadline conditions. Also, visual errors do not occur when gestures are made in response to words under a deadline (Experiment 2), which indicates that the visual route is specific to seen objects.     

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)