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We studied the effects of both unilateral and bilateral lesions of the central nucleus of the anterior archistriatum (AAc) on the production of contact calls and warble song in adult male and female budgerigars. Birds were sorted into three experimental groups based on the percentage of AAc destroyed and whether lesions were unilateral or bilateral. The experimental groups were Unilateral Lesion (N = 8), Partial Bilateral Lesion (N = 5), and Bilateral Lesion birds (N = 12). Each group contained both sexes. Unilateral lesions had no demonstrable effects on contact call or warble song production. Bilateral lesions resulted in immediate and permanent disruption of all learned temporal and spectral characteristics of contact calls, although call initiation was not dependent on the AAc. Partial bilateral lesion effects varied with lesion size and location. At least 20-30% sparing of the AAc, including sparing portions of both the dorsal (AAcd) and ventral (AAcv) subdivisions on the same side of the brain, is necessary for production of prelesion contact call patterns. Warble song was absent in birds with complete bilateral destruction. Two birds with large yet incomplete lesions of the AAc sang after surgery, although the warble song of these birds was extremely impoverished and contained only a few of the typical warble song elements. Lesion results indicate that the AAc mediates the production of learned vocal features in male and female budgerigars, with each hemisphere capable of supporting a normal vocal repertoire. 相似文献
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Neurological and behavioral findings indicate that atypical auditory processing characterizes autism. The present study tested the hypothesis that auditory processing is less domain-specific in autism than in typical development. Participants with autism and controls completed a pitch sequence discrimination task in which same/different judgments of music and/or speech stimulus pairs were made. A signal detection analysis showed no difference in pitch sensitivity across conditions in the autism group, while controls exhibited significantly poorer performance in conditions incorporating speech. The results are largely consistent with perceptual theories of autism, which propose that a processing bias towards featural/low-level information characterizes the disorder, as well as supporting the notion that such individuals exhibit selective attention to a limited number of simultaneously presented cues. 相似文献
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Resource-limited regions of the world represent the areas most affected by the global HIV epidemic. Currently, there are insufficient
data on the neurocognitive effects of HIV in these areas and neuropsychological studies that have been carried out thus far
are marked by inconsistent methods, test batteries, and rating systems for levels of cognitive impairment. These differences
in methods, along with genetic variability of both virus and host, differences in co-infections and other co-morbidities,
differences in language and culture, and infrastructural deficiencies in many international settings create challenges to
the assessment of neurocognitive functioning and interpretation of neuropsychological data. Identifying neurocognitive impairment
directly attributable to HIV, exploring relationships between HIV-associated neurocognitive impairment, disease variables,
and everyday functioning, evaluating differences in HIV-1 subtype associated neuropathology, and determining implications
for treatment remain complicated and challenging goals. Endeavors to establish a more standardized approach to neurocognitive
assessments across international studies in addition to accumulating appropriate normative data that will allow more accurate
rating of neuropsychological test performance will be crucial to future efforts attempting to achieve these goals. 相似文献
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Application of a neuropsychological perspective to the study of schizophrenia has established a number of important facts
about this disorder. Some of the key findings from the existing literature are that, while neurocognitive impairment is present
in most, if not all, persons with schizophrenia, there is both substantial interpatient heterogeneity and remarkable within-patient
stability of cognitive function over the long-term course of the illness. Such findings have contributed to the firm establishment
of neurobiologic models of schizophrenia, and thereby help to reduce the social stigma that was sometimes associated with
purely psychogenic models popular during parts of the 20th century. Neuropsychological studies in recent decades have established
the primacy of cognitive functions over psychopathologic symptoms as determinants of functional capacity and independence
in everyday functioning. Although the cognitive benefits of both conventional and even second generation antipsychotic medications
appear marginal at best, recognition of the primacy of cognitive deficits as determinants of functional disability in schizophrenia
has catalyzed recent efforts to develop targeted treatments for the cognitive deficits of this disorder. Despite these accomplishments,
however, some issues remain to be resolved. Efforts to firmly establish the specific neurocognitive/neuropathologic systems
responsible for schizophrenia remain elusive, as do efforts to definitively demonstrate the specific cognitive deficits underlying
specific forms of functional impairment. Further progress may be fostered by recent initiatives to integrate neuropsychological
studies with experimental neuroscience, perhaps leading to measures of deficits in cognitive processes more clearly associated
with specific, identifiable brain systems. 相似文献
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S C Heaton S K Reader A S Preston E B Fennell O E Puyana N Gill J H Johnson 《Child neuropsychology》2001,7(4):251-264
The present study explores the utility of the Test of Everyday Attention for Children (TEA-Ch) as a measure of the attentional impairments displayed by children with Attention Deficit Hyperactivity Disorder (ADHD). Sixty-three children with ADHD and 23 non-ADHD Clinical Control children were compared on subtests of the TEA-Ch reflecting three attentional domains: sustained, selective, and attentional control. Results show that children with ADHD performed significantly worse than clinical controls on subtests of sustained attention and attentional control. The groups did not differ, however, on subtests of selective attention. These findings suggest that the TEA-Ch is sensitive to attentional deficits unique to ADHD and holds promise as a useful tool in the assessment of ADHD. Performance patterns and future directions are discussed. 相似文献
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J T Heaton S E Brauth 《Journal of comparative psychology (Washington, D.C. : 1983)》1999,113(3):314-320
The effects of complete and partial cochlear extirpation at ages 9-11 days posthatch were assessed in 5 nestling budgerigars (Melopsittacus undulatus) to determine if auditory feedback is necessary for the production of nestling vocalizations. Although early deafening had no effect on the production of food-begging calls produced during the first 2 weeks posthatch, deafening did disrupt the expected transition from these early calls to the longer and more complex frequency-modulated, patterned food-begging calls normally appearing 3-4 weeks posthatch. All birds sustaining either complete or partial cochlear extirpation failed to develop stereotyped contact calls around the time of fledging at 5 weeks. These results are consistent with previous research showing that deafened nestlings do not develop normal contact calls (R. J. Dooling, B. F. Gephart, P. H. Price, C. McHale, & S. E. Brauth, 1987) and also indicate that a form of sensorimotor learning is involved in the production of mature, patterned food-begging calls in budgerigars. 相似文献
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Scott JC Woods SP Matt GE Meyer RA Heaton RK Atkinson JH Grant I 《Neuropsychology review》2007,17(3):275-297
This review provides a critical analysis of the central nervous system effects of acute and chronic methamphetamine (MA) use,
which is linked to numerous adverse psychosocial, neuropsychiatric, and medical problems. A meta-analysis of the neuropsychological
effects of MA abuse/dependence revealed broadly medium effect sizes, showing deficits in episodic memory, executive functions,
information processing speed, motor skills, language, and visuoconstructional abilities. The neuropsychological deficits associated
with MA abuse/dependence are interpreted with regard to their possible neural mechanisms, most notably MA-associated frontostriatal
neurotoxicity. In addition, potential explanatory factors are considered, including demographics (e.g., gender), MA use characteristics
(e.g., duration of abstinence), and the influence of common psychiatric (e.g., other substance-related disorders) and neuromedical
(e.g., HIV infection) comorbidities. Finally, these findings are discussed with respect to their potential contribution to
the clinical management of persons with MA abuse/dependence. 相似文献
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