Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “OVERLEARNING”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources

The contribution of the insula to motor aspects of speech production: a review and a hypothesis.

Based on clinical and functional imaging data, the left anterior insula has been assumed to support prearticulatory functions of speech motor control such as the "programming" of vocal tract gestures. In order to further elucidate this model, a recent functional magnetic resonance imaging (fMRI) study of our group (Riecker, Ackermann, Wildgruber, Dogil, & Grodd, 200) investigated both overt (aloud) and covert (silent) production of highly overlearned word strings ("automatic speech"), based on the suggestion that "inner speech" might provide a "window" into preparatory motor activities (Jeannerod, 1994). As a control condition, subjects were asked to reproduce a nonlyrical tune. In contrast to hemodynamic responses within motor cortex and cerebellum, activation of the intrasylvian cortex turned out to be bound to overt task performance. Rather than prearticulatory processes, these findings suggest the left insula to contribute to the actual coordination of the up to 100 muscles engaged in articulation and phonation. Conceivably, the association of speech production with intrasylvian cortex might have evolved within the framework of phylogenetically older connections between the insula and limbic structures, on the one hand, and nonspeech functions of the upper midline musculature such as swallowing, on the other. Whereas (overt) speech tasks predominantly elicit activation within left anterior insula, reproduction of a nonlyrical tune yielded an opposite response pattern. Conceivably, the opposite distributional pattern of speaking and singing at the level of intrasylvian cortex reflects operation of the two hemispheres across different time domains ("double filtering by frequency theory": left hemisphere=segmental information, right hemisphere=intonation contours of verbal utterances and musical melodies; ). In line with this suggestion, a further study of our group (Ackermann et al., 2001) provided first evidence that differential hemispheric filtering might be bound to insular cortex.

Brain Mapping↗

The effects of V4 lesions on the visual abilities of macaques: hue discrimination and colour constancy.

Monkeys with lesions of cortical visual area V4 were compared with unoperated monkeys in three experiments. In Expt. 1 they were tested for the reacquisition of a pre-operatively learned hue discrimination task. In Expt. 2, as a test of colour constancy, the monkeys were required to perform previously overlearned colour discrimination tasks when the amounts of red, green and blue light in the illuminant were changed. In Expt. 3 the animals were compared on the post-operative acquisition of hue, greyness and saturation discrimination tasks. The results of Expt. 1 showed that monkeys with V4 lesions can regain their pre-operative levels of performance on hue discrimination tasks. Expt. 2 showed that monkeys with V4 lesions have a colour constancy deficit. Expt. 3 reinforced the finding that the animals with V4 lesions could learn to perform fine hue discriminations but that their final, asymptotic performance was not as reliable as that of normal animals. The wavelength discrimination data are discussed within the context of recent electrophysiological findings that V4 is involved in selective attention to visual stimuli and the constancy data are interpreted as evidence that V4 is important for defining colour constancy thresholds but not for constructing the perceptual categories underlying constant colour perception.

Animals↗

Assessing dressing ability in dementia.

Cognitive impairment can profoundly affect the skills required for activities of daily living (ADL). Most cognitive screening measures assess cognitive status rather than the cognitive functions that underlie ADL tasks. The dressing assessment guide (DAG) assesses the cognitive and functional abilities in dressing of patients with dementia. The DAG evaluates everyday and overlearned tasks and uses cues to provide a context for action. Nurses can easily administer the guide, and the resulting data provide the basis for nursing interventions.

Activities of Daily Living↗

Does the cerebellum contribute to cognitive aspects of speech production? A functional magnetic resonance imaging (fMRI) study in humans.

Several positron emission tomography (PET) studies suggest a contribution of the lateral aspects of the right cerebellar hemisphere to higher-level (cognitive) aspects of speech production such as controlled verbal response selection. As an alternative, however, 'inner speech', giving rise to subliminal activity of orofacial and laryngeal muscles, might account for the observed activation effects. Eighteen subjects underwent functional magnetic resonance imaging (fMRI) during continuous silent recitation of the names of the months of the year ('automatic speech'). The right cerebellar hemisphere showed a significantly increased hemodynamic response concomitant with, among others, an asymmetric activation pattern towards the left side at the level of the motor strip. Since highly overlearned word strings, presumably, pose few demands on controlled response selection and since the projections of the right cerebellar hemisphere to the left precentral gyrus participate in motor control, the observed cerebellar activation, thus, seems to be related to the articulatory level of speech production rather than, as suggested by previous PET studies, to cognitive operations.

Adult↗

Word learning deficit among Chinese dyslexic children.

The present study examined word learning difficulties in Chinese dyslexic children, readers of a nonalphabetic script. A total of 105 Hong Kong Chinese children were recruited and divided into three groups: Dyslexic (mean age 8;8), CA control (mean age 8;9), and RL control (mean age 6; 11). They were given a word learning task and a familiar word writing task. It was found that the Dyslexic group performed less well than the RL group in learning irregular words over trials but not the regular ones. Error analyses showed that the Dyslexic group made more orthographic and word association errors but less intra-wordlist interference errors than the RL control group. The Dyslexic group also performed significantly less well than both control groups in writing familiar words (e.g. their own name). These findings suggest that Chinese dyslexic children have difficulty learning new words, especially irregular ones, and retaining overlearned words in long-term memory. We conclude that Chinese dyslexic children have a specific impairment in word learning like their alphabetic counterparts.

Case-Control Studies↗

Choking under pressure: self-consciousness and paradoxical effects of incentives on skillful performance.

Choking under pressure is defined as performance decrements under circumstances that increase the importance of good or improved performance. A model for choking on coordination and skill tasks is proposed, holding that the pressure increases the conscious attention to the performer's own process of performance and that this increased conscious attention disrupts the automatic or overlearned nature of the execution. Six experiments provided data consistent with this model. Three studies showed that increased attention to one's own process of performance resulted in performance decrements. Three other studies showed similar decrements produced by situational manipulations of pressure (i.e., implicit competition, a cash incentive, and audience-induced pressure). Individuals low in dispositional self-consciousness were shown to be more susceptible to choking under pressure than those high in it.

Achievement↗

Processing determinants of reading speed.

Two groups of university undergraduates differing in reading ability were tested on a number of reaction-time tasks designed to determine the speed of encoding visual information at several different levels. In addition, the subjects were given tests of sensory functions, verbal and quantitative reasoning ability, short-term auditory memory span, and ability to comprehend spoken text. The groups did not differ on the sensory tests. However, the faster reader group had faster reaction times on all of the reaction-time tasks, and the size of the fast-reader advantage increased with the mean reaction time. Faster readers also performed more accurately in verbal and quantitative reasoning, short-term auditory memory, and speech comprehension. Regression analyses suggested that the ability to comprehend spoken material and speed of accessing overlearned memory codes for visually presented letters represented two important independent correlates of reading ability in our sample of subjects. Two variables reflecting these abilities--the percentage of correct answers to a listening comprehension test and the reaction time for correct responses in a letter-matching task--accounted for nearly all of the variance in reading ability tapped by both of our reading tests. In a second experiment, no reaction-time difference was found between fast and average readers in a matching task requiring no long-term memory code access but considerable visual information processing as indexed by overall mean reaction time. The results supported the conclusion that one skill allowing fast readers to capture more information from each reading fixation is faster access to letter codes from print.

Concept Formation↗

Do different metamemory judgments tap the same underlying aspects of memory?

We compared the predictions from several kinds of metamemory judgments (on the same set of items), both in terms of their predictive accuracy and in terms of the commonality of predictions. Undergraduates made judgments about the ease with which they could learn each item in a list (ease-of-learning judgments); then they learned every item, either to a minimal criterion of learning or with overlearning, and made judgments about how well they knew each item (judgments of knowing); finally, they returned 4 weeks later for a retention session and made feeling-of-knowing judgments on every time they could not recall, after which a recognition test assessed predictive accuracy. Ease-of-learning judgments had the least predictive accuracy. Surprisingly, however, the recognition of nonrecalled items was predicted equally well by judgments of knowing (made 4 weeks earlier) as by feeling-of-knowing judgments (made immediately prior to recognition). Moreover, those two kinds of judgments were only weakly correlated with each other, which implies that they do not tap memory in the same way.

Attention↗

Effect of pairing red nucleus and motor thalamic lesions on reaching toward moving targets in cats.

The small effects of bilateral lesions of motor thalamus on motor control and the transient deficits induced by bilateral kainic red nucleus (RN) lesions have been explained by a parallel competitive role of the cortico- and rubro-spinal pathways. Either pathway can take over motor control if the other is damaged. In this study the effect of bilateral and simultaneous lesions of both RN and motor thalamus was analyzed on cats overtrained to reach toward a moving target. After lesion, accuracy was impaired, movement onset was delayed, and movement execution was perturbed. However, postoperative retraining led to full recovery of the preoperative accuracy level although movement latency remained higher. The relative mildness of the long-lasting deficit after lesioning 2 main motor brain structures underlines the robustness of overlearned movements and widens the idea of parallelism in the motor system to other (subcortical?) pathways.

Animals↗

Sudden onset of stuttering: a case report.

This report describes a 28-year-old male who suddenly began to stutter after an attempted suicide. The patient had a history of one prior stuttering episode lasting approximately one week, also following a suicide attempt. The speech evaluation documented that the patient stuttered on automatic overlearned social responses, during choral reading, during singing, while under the influence of white noise, and during an initial trial of delayed auditory feedback (DAF). In addition, the patient produced stuttering-like repetitions while merely miming speech. He did not demonstrate secondary stuttering symptoms and his nonfluencies were almost exclusively repetitions of initial or stressed syllables. An intervention program using DAF was initiated and in approximately one month the frequency of stuttering had markedly decreased. The behaviors exhibited by this patient are considered to characterize stuttering of sudden onset in adults due to significant psychological distress.

Adult↗

Syntactic preservation in Alzheimer's disease.

Language ability of 20 patients with probable Alzheimer's disease (AD) was evaluated. Analysis of spontaneous speech revealed a normal range and frequency of syntactic constructions but poor lexical use. A writing task showed a similar divergence, with the ability to use syntactic cues significantly more intact than the ability to use semantic cues. The results are taken to indicate that syntactic ability is selectively preserved in AD. These findings are consistent with a modular theory of grammar and of mental functions more generally. A tentative explanation of these phenomena is proposed in which the overlearned and automatic nature of syntactic ability helps account for its resilience to cognitive dissolution and cortical degeneration.

Aged↗

Life-span development of odor identification, learning, and olfactory sensitivity.

In the first of three studies, children (aged 8 to 14 years) were found to perform worse than young and middle-aged adults in unprompted identification of doors, with average performance much like that of elderly adults. Comparisons on other tasks, specifically odor threshold, prompted odor identification, and object naming (Boston Naming Test), across the life span (five groups) revealed that children have the same excellent olfactory sensitivity as young adults and merely lack odor-specific knowledge that accumulates slowly through life. Such knowledge apparently accumulates so slowly that age-associated discriminative losses, measurable by early middle age, begin to wear away gains obtained through experience before odors can become overlearned. In the second study, a novel adaptive psychophysical method, the step procedure, confirmed the equivalent sensitivity of children and young adults. In the third study, a paired-associate task illustrated the sluggish course of odor learning. Young adults outperformed children, though the youngest group, first graders, made up ground relatively fast. For children and adults, common odors facilitated performance relative to novel odors. The outcome highlighted the relevance of semantic factors in odor learning irrespective of age.

Adolescent↗

Null effect of mood as a semantic prime.

Semantic tasks, such as lexical decision making and word recognition, have not produced a mood priming effect. Earlier studies have been criticized because they included (a) mood induction techniques that required instruction to feel the mood, and (b) the use of overlearned tasks that did not require controlled processing. In this pair of experiments, the authors attempted to address these criticisms. However, the results of this study did not demonstrate a mood priming effect for happy and sad subjects who appraised sentence content as being happy or sad. The results of this study supported the dissociation of semantic and episodic memory.

Adult↗

Developing positive intimacy cognitions in males with a history of nonintimate sexual experiences.

Traditional male sexual socialization is based on assumptions and cognitions which are antithetical to adult intimate relationships. The double standard scenario, initial sexual experiences, the way of talking about sex with peers, cognitions around automatic and autonomous functioning, the criterion of perfect performance, orgasm-orientation, and emotional separateness from females are strongly overlearned and reinforced in the young male subculture. A cognitive-behavioral strategy is used to increase intimacy among couples as well as males without partners. The focus is on increasing comfort, self-disclosure, and increasing the range of emotional and sexual expression.

Cognition↗

Changes in cerebral functioning associated with normal aging.

It has been suggested that the normal aging process is characterized by a pattern of neuropsychological performance decline that implies relatively greater vulnerability of right-hemisphere functions. This hypothesis was tested in a sample of 68 volunteers aged 20-75 who were free of systemic and neurologic illness. Neuropsychologic measures of lateralized and focal function were specifically selected to eliminate systematic procedural differences among tests (e.g., timed vs. untimed, overlearned vs. unfamiliar). Inferences about the localizing significance of each measure were based on previously demonstrated double dissociation of function in lesion studies. Results suggested that declines in cerebral efficiency are not differentially lateralized. Age correlated performance changes implied bilateral reduction that was significantly more pronounced on operations associated with frontal-lobe function. Anatomic and theoretical explanations for this pattern were discussed.

Adult↗

Influence of a stressing constraint on stiffness and damping functions of a ski simulator's platform motion.

The aim of this study was to assess the effect of stress on a previously acquired motor coordination. Following a longitudinal learning experiment, four participants performed oscillations on a ski simulator, either in normal or stressful conditions. The results showed that the amplitude of the oscillations decreased under stress, but no significant effect was seen regarding coordination, suggesting the strong resistance to stress of overlearned behaviour. Nevertheless, for one participant, a transient regression towards a former stage of learning was observed. This result was consistent with the regression hypothesis formulated by Fuchs (1962).

Adult↗

Evidence for disproportionate dual-task costs in older adults for episodic but not semantic memory.

Previous research demonstrates that older adults are poor at dual tasking, but there is less agreement on whether their decrement is worse than that predicted from single-task performance. This study investigated whether task domain moderates dual-task costs in old age. In two experiments, young and older adults retrieved either previously learned associates (episodic retrieval) or overlearned category members (semantic retrieval) under single or working-memory load conditions, using cued recall (Experiment 1) and recognition (Experiment 2) procedures. In both experiments the proportional costs of dual tasking were age invariant for semantic retrieval but were particularly marked for episodic retrieval, although the size of the age effect was reduced in recognition compared to cued recall. The data suggest that age effects in dual tasking may be domain specific.

Adult↗

Verbal fluency patterns in two subgroups of patients with Alzheimer's disease.

Previous research has identified two subgroups of patients with Alzheimer's disease (AD) based on performance discrepancies on semantic and visual-constructional measures: Left AD (LAD) and Right AD (RAD). In this study, verbal fluency performances (Animal Fluency [AF] and Letter Fluency [FAS]) of these two subgroups were examined. It was hypothesized that LAD patients would perform worse on AF compared to FAS, due to an underlying breakdown of left-hemisphere semantic networks. On the other hand, the RAD group, which theoretically has a relatively preserved semantic system, yet difficulties retrieving overlearned information, was not expected to differ on the two fluency tasks. These predictions were based on the notion that the AF task requires intact retrieval and semantic processes, whereas the FAS task is reliant on retrieval processes alone. Patients were classified into subgroups on the basis of performance discrepancies on the Boston Naming Test (BNT) and Copy tasks: LAD (BNT < Copy); RAD (BNT > Copy). A split-plot ANOVA using demographically corrected standard T-scores revealed a significant main effect for fluency task, and a significant subgroup x fluency task interaction. LAD patients performed poorer on AF compared to FAS; there was no fluency task difference for the RAD group. Analysis of within-subcategory response clustering on AF revealed more instances of serial subclass exemplar responses by RAD members. These results support the loss theory in explaining the semantic deficit of LAD, and suggest that retrieval difficulties underlie the fluency problems of RAD.

Aged↗