Cognitive Neuropsychological Analysis and Neuroanatomic Correlates in a Case of Acute Anomia

Raymer, Anastasia; Foundas, Anne L.; Maher, Lynn M.; Greenwald, Margaret; Morris, Michael; Rothi, Leslie J. Gonzalez; Heilman, Kenneth M.

doi:10.1006/brln.1997.1786

Cited by 112 publications

(68 citation statements)

References 18 publications

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“…Along with the observations that different kinds of anomia are associated with disruption of different brain areas (DeLeon et al, 2007;Hillis et al, 2001;Raymer et al, 1997), we demonstrated that the time course of brain activity during impaired picture naming reflects the disrupted process underlying different anomic behaviors. Divergent electrocortical processing starting after 100 msec appeared in patients having a lexical-semantic impairment, indicating impairment in the processes preceding word form encoding.…”

Section: Discussionsupporting

confidence: 71%

Time Course of Evoked-potential Changes in Different Forms of Anomia in Aphasia

Laganaro

Morand

Schnider

2009

Journal of Cognitive Neuroscience

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Abstract& Impaired word production after brain damage can be due to impairment at lexical-semantic or at lexical-phonological levels of word encoding. These processes are thought to involve different brain regions and to have different time courses. The present study investigated the time course of electrophysiological correlates of anomia in 16 aphasic speakers, divided in two subgroups according to their anomic pattern (8 with lexicalsemantic impairment and 8 with lexical-phonological impairment), in comparison to 16 healthy control subjects performing the same picture naming task. Differences in amplitudes and in topographic maps between groups were differently distributed when the whole heterogeneous group of aphasic patients was compared to the control group and when the two more homogeneous subgroups of anomic patients were analyzed. The entire aphasic group expressed different waveforms and topographic patterns than the control group starting about 100 msec after picture presentation. When two subgroups of aphasic patients are considered according to the underlying cognitive impairment, early event-related potential (ERP) abnormalities (100-250 msec) appeared only in the lexical-semantic subgroup, whereas later ERP abnormalities (300-450 msec) occurred only in the lexical-phonological subgroup. These results indicate that the time windows of ERP abnormalities vary depending on the underlying anomic impairment. Moreover, the findings give support to current hypotheses on the time course of processes involved in word production during picture naming. &

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Section: Discussionsupporting

confidence: 71%

Time Course of Evoked-potential Changes in Different Forms of Anomia in Aphasia

Laganaro

Morand

Schnider

2009

Journal of Cognitive Neuroscience

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“…the stimuli in the present experiment were detailed colored objects and repeated items were presented multiple times before the critical test trial, but participants performed the same orienting task (size judgments) for the objects on each presentation; in contrast, the stimuli in the divided visual field study were black and white line drawings, participants performed a different task during the initial exposure than during the test trial (one of three different orienting tasks vs. confrontation naming on the test trial), and objects at test were presented either to the right or left visual field for only 17 ms each.] naming or tagging stimuli that are recognizable [[6]; also see [45]]. Consistent with this possibility, recent PET evidence [42] indicates that patients with semantic dementia, who show especially pronounced difficulties in naming, demonstrate less activation in this region (coordinates of −54, − 52, −10) than do normal controls during semantic comparison tasks involving both pictures and words.…”

Section: Discussionmentioning

confidence: 85%

“…These studies have shown that the behavioral priming that results from repeated exposure to a stimulus also is associated with indications of enhanced 'neural efficiency': some of the brain regions initially involved in the processing of a stimulus show reduced activity during repeated processing of the stimulus. Reductions in neural activity for repeated compared to novel stimuli have been observed in several regions of left frontal cortex that are believed to be involved in accessing or evaluating semantic or phonological representations (Brodmann areas 47,45,44) [10,16,20,44]. Similar reductions have been observed in several posterior cortical regions involved in perceptual or form recognition, including occipitotemporal and occipital cortices [ [8,9,40,55,58]; for review see [54,70]].…”

Section: Introductionmentioning

confidence: 86%

Perceptual specificity in visual object priming: functional magnetic resonance imaging evidence for a laterality difference in fusiform cortex

et al. 2001

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Seeing an object on one occasion may facilitate or prime processing of the same object if it is later again encountered. Such priming may also be found -but at a reduced level -for different but perceptually similar objects that are alternative exemplars or 'tokens' of the initially presented object. We explored the neural correlates of this perceptual specificity using event-related functional magnetic resonance imaging (fMRI) procedures, contrasting neural activity when participants made object classification decisions (size judgments) regarding previously presented objects (repeated same), alternative exemplars of previously presented objects (repeated different), or entirely new objects (novel). Many frontal regions (including bilateral frontal operculum, bilateral posterior inferior frontal/precentral, left anterior inferior frontal, and superior frontal cortices) and multiple late visual and posterior regions (including middle occipital, fusiform, fusiform-parahippocampal, precuneus, and posterior cingulate, all bilaterally), demonstrated reduced neural activity for repeated compared to novel objects. Greater repetition-induced reductions were observed for same than for different exemplars in several of these regions (bilateral posterior inferior frontal, right precuneus, bilateral middle occipital, bilateral fusiform, bilateral parahippocampal and bilateral superior parietal). Additionally, right fusiform (occipitotemporal) cortex showed significantly less priming for different versus same exemplars than did left fusiform. These findings converge with behavioral evidence from divided visual field studies and with neuropsychological evidence underscoring the key role of right occipitotemporal cortex in processing specific visual form information; possible differences in the representational-functional role of left fusiform are discussed.

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“…A few studies of acute or subacute stroke have indicated that lesions or hypoperfusion of left BA 37 is associated with impaired naming without comprehension deficits (Raymer et al, 1997;Foundas et al, 1998), but these studies have not evaluated the possibility that other regions are also essential for naming. Functional imaging studies often show activation of left BA 37 in modality-independent lexical processing (Price et al, 2003;Tranel et al, 2005), indicating that this area may be recruited in a variety of lexical tasks, including naming.…”

Section: Discussionmentioning

confidence: 99%

Restoring Cerebral Blood Flow Reveals Neural Regions Critical for Naming

et al. 2006

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We identified areas of the brain that are critical for naming pictures of objects, using a new methodology for testing which components of a network of brain regions are essential for that task. We identified areas of hypoperfusion and structural damage with magnetic resonance perfusion-and diffusion-weighted imaging immediately after stroke in 87 individuals with impaired picture naming. These individuals were reimaged after 3-5 d, after a subset of patients underwent intervention to restore normal blood flow, to determine areas of the brain that had reperfused. We identified brain regions in which reperfusion was associated with improvement in picture naming. Restored blood flow to left posterior middle temporal/fusiform gyrus, Broca's area, and/or Wernicke's area accounted for most acute improvement after stroke. Results show that identifying areas of reperfusion that are associated with acute improvement of a function can reveal the brain regions essential for that function.

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Cognitive Neuropsychological Analysis and Neuroanatomic Correlates in a Case of Acute Anomia

Cited by 112 publications

References 18 publications

Time Course of Evoked-potential Changes in Different Forms of Anomia in Aphasia

Time Course of Evoked-potential Changes in Different Forms of Anomia in Aphasia

Perceptual specificity in visual object priming: functional magnetic resonance imaging evidence for a laterality difference in fusiform cortex

Restoring Cerebral Blood Flow Reveals Neural Regions Critical for Naming

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