Production Task (production + task)

Distribution by Scientific Domains

Selected Abstracts

Lack of prefrontal repetitive transcranial magnetic stimulation effects in time production processing

A. Gironell
The aim of the present study was to determine the effects of high frequency repetitive transcranial magnetic stimulation (rTMS) over different neuroanatomical areas [left and right doroslateral prefrontal cortex (DLPFC) and right cerebellar hemisphere] on time production task. The study was performed in 16 healthy right-handed men with a cross-over, within subject repeated measures design. There were four rTMS conditions: baseline without stimulation, high frequency rTMS over right, left DLPFC and over right cerebellum. The volunteers were asked to produce a 3-min interval by internal counting. The rTMS was applied during the task. No significantly differences were observed in absolute error scores in time estimation task with any rTMS condition. This preliminary study does not support the role of the prefrontal lobe in time production processes. [source]

Means-End Behavior in Young Infants: The Interplay of Action Perception and Action Production

INFANCY, Issue 6 2009
Moritz M. Daum
In 2 experiments, the interplay of action perception and action production was investigated in 6-month-old infants. In Experiment 1, infants received 2 versions of a means-end task in counterbalanced order. In the action perception version, a preferential looking paradigm in which infants were shown an actor performing means-end behavior with an expected and an unexpected outcome was used. In the action production version, infants had to pull a cloth to receive a toy. In Experiment 2, infants' ability to perform the action production task with a cloth was compared to their ability to perform the action production task with a less flexible board. Finally, Experiment 3 was designed to control for alternative low-level explanations of the differences in the looking times toward the final states presented in Experiment 1 by only presenting the final states of the action perception task without showing the initial action sequence. Results obtained in Experiment 1 showed that in the action perception task, infants discriminated between the expected and the unexpected outcome. This perceptual ability was independent of their actual competence in executing means- end behavior in the action production task. Experiment 2 showed no difference in 6-month-olds' performance in the action production task depending on the properties of the support under the toy. Similarly, in Experiment 3, no differences in looking times between the 2 final states were found. The findings are discussed in light of theories on the development of action perception and action production. [source]

Action monitoring in motor control: ERPs following selection and execution errors in a force production task

Ellen R. A. De Bruijn
Abstract Action monitoring has been studied in many tasks by means of measuring the error-related negativity (Ne/ERN), but never in a motor control task requiring precise force production. Errors in discrete choice reaction tasks are the result of incorrect selections, but errors in force production can also arise from incorrect executions. ERPs were obtained while participants produced low or high isometric forces with their left or right hand. As expected, incorrect choices of hand elicited an Ne/ERN. Interestingly, Ne/ERNs were also present in the less discrete selection error of an incorrect choice of force, but only when erroneously a low instead of a high force was chosen. In both force ranges, no Ne/ERNs were found after errors in execution. These errors showed a large positivity in feedback ERPs and, similar to correct responses, a prolonged negativity in response ERPs. We propose that, compared to selection errors, the time uncertainty aspects of execution errors and the resulting changing response representations prohibit error detection by the internal monitoring system responsible for generating the Ne/ERN. [source]

Overtensing and the effect of regularity

Joseph Paul Stemberger
Abstract Regularly inflected forms often behave differently in language production than irregular forms. These differences are often used to argue that irregular forms are listed in the lexicon but regular forms are produced by rule. Using an experimental speech production task with adults, it is shown that overtensing errors, where a tensed verb is used in place of an infinitive, predominantly involve irregular forms, but that the differences may be due to phonological confounds, not to regularity per se. Errors involve vowel-changing irregular forms more than suffixing inflected forms, with at best a small difference between regular -ed and irregular -en. Frequency effects on overtensing errors require a model in which the past-tense and base forms of the verb are in competition and in which activation functions are nonlinear, and rule out models with specialized subnetworks for past-tense forms. Implications for theories of language production are discussed. [source]


Ragnar Tveteras
ABSTRACT Agglomeration externalities can have positive effects on both the production possibility frontier and technical inefficiency of firms. Increased levels of localized knowledge spillovers and substitution of internal inputs with external inputs may lead to fewer errors in decision-making and execution of production tasks, thus causing firms to become technically more efficient relative to the production frontier. When we estimate a stochastic frontier production model on a large panel of salmon aquaculture farms, we find econometric support for positive agglomeration externalities on both the production frontier and technical inefficiency. [source]

Emergence of Graphic Symbol Functioning and the Question of Domain Specificity: A Longitudinal Training Study

Tara C. Callaghan
The impact of social scaffolding on the emergence of graphic symbol functioning was explored in a longitudinal training study. Links among graphic, language, and play domains in symbolic development were also investigated. The symbolic functioning of 16 children, who were 28 months at the outset of the study, was assessed in comprehension and production tasks across the three domains at monthly intervals from 28 to 36 months, and again at 42 months. Training was delivered in between monthly assessments during weekly visits. Half of the children received training, which consisted of the experimenter drawing common objects and highlighting the relation between pictures and their referents, for 16 consecutive weeks early in the study (early training, ET). The remaining half received a placebo version of training for these 16 weeks, followed by actual training for 4 weeks in the fifth month (late training, LT). After the first 4 months of training the ET group was found to have accelerated comprehension and production of graphic symbols relative to the LT group. After the fifth month, the LT group reached the same level of graphic symbol performance as the ET group. There were strong positive correlations found among graphic symbol functioning and language and play, and between play and language. These findings support the view that graphic symbolic development can be influenced by cultural scaffolding, that more extensive training is needed early rather than later in development, and that interrelationships exist among symbolic domains. [source]