Displacement Task Research Articles

Object concept and mental representation inCebus apella andMacaca fascicularis

The achievement of Stage 6 object concept as an index of the representational capacity, was studied both in juveniles and adults of two nonhuman primate species,Cebus apella andMacaca fascicularis. The general goal of the present investigation was to evaluate the real nature of the strategy adopted by subjects searching an object in the invisible displacement task. To this purpose, the original Piagetian version of the invisible displacement task was used modifying some parameters and employing additional tasks and analyses in order to differentiate representational solutions from the nonrepresentational ones. With this method it was found that an adult cebus, but not macaques, solved the invisible displacement task with the use of the mental representation.

The 1984 Natl. Petroleum Council Estimate of Potential EOR for Miscible Processes

Summary In March 1982, the Secretary of Energy requested the Natl. Petroleum Council (NPC) to evaluate the EOR potential of the U.S. The NPC Committee on EOR was formed to fulflll this request. Under this committee, a coordinating subcommittee and four working task groups were selected to perform the study. This paper describes the work of the Miscible Displacement Task Group and reports their findings and conclusions on the potential for EOR by miscible processes in known U.S. reservoirs. In conjunction with the coordinating subcommittee and the other task groups, the Miscible Displacement Task Group helped upgrade the DOE reservoir data base into the most comprehensive data base available to date on U.S. reservoirs. A miscible process and economic screening model prepared under contract for the DOE was analyzed, modified, and calibrated by the Miscible Displacement Task Group for this study. With physical screening parameters, the Miscible Displacement Task Group selected reservoirs susceptible to miscible processes from the data base, and then processed them with the NPC model to estimate tertiary oil recovery. Sensitivity to oil prices and rate of return (ROR) were investigated, and the results were combined with the results from the other process task groups (thermal and chemical) to reach an overall assessment of the EOR potential in the U.S. The potential EOR for miscible flooding is estimated to vary between 2.0×109 and 8.5×109 bbl [0.32×109 and 1.4×109 m3] over the range of prices and technologies considered. Peak rate varies from 200×103 to 980×103 B/D [32×103 to 156×103 m3/d] for the cases investigated. Introduction Field tests and full-scale operations of EOR have increased in recent years. Research in the basic fluid behavior and specific reactions of reservoir fluids to heat, chemicals, and miscible fluids have increased industry knowledge of EOR processes. These activities and the growing importance of increasing potential oil recovery in the U.S. prompted the Secretary of Energy to request the NPC to evaluate the EOR potential from known reservoirs. This paper reports on the methodology used and results developed by the Miscible Displacement Task Group. Miscible floods to date have used CO2, N2, and hydrocarbons as miscible solvents. Commercial hydrocarbon miscible floods have been operated since the 1950's. CO2 miscible flooding on a large scale is relatively recent, and CO2 is expected to be the significant solvent used in the future. There were at least 11 commercial, large-scale CO2 projects under way in Dec. Several additional commercial projects have been started in west Texas. Since then, development of natural sources of CO2 in Colorado, New Mexico, and Mississippi are in progress. All these activities indicate that CO2 miscible flooding will be a significant EOR process. In this study, two levels of technology, designated as implemented and advanced, were considered. The implemented-technology case is based on current project design used in recent field projects. A CO2 slug size equivalent to 40% of the HCPV was assumed, along with a water-alternating-gas (WAG) ratio of 1.5:1. The advanced-technology case assumed that certain improvements in technology would be developed and available for full-scale operations in 1995. For reservoirs with moderate heterogeneity, those with good waterflood sweep efficiency, the volume of CO2 injected was increased. For more highly stratified, heterogeneous reservoirs, it was assumed that "foam" chemicals would be developed to control the flow of CO2 and to improve the sweep efficiency. The estimated potential for miscible EOR from known reservoirs varies between 2.0×109 and 8.5×109 bbl [0.32×109 and 1.4×109 m3] over the range of oil prices considered. The peak rate of EOR production from miscible flooding varies between 200×103 and 980×103 B/D [32×103 and 156×103 m3/d] for the same cases. These ranges cover both the implemented- and advanced-technology cases. Related papers: SPE 13239, SPE 13240, SPE 13241 Related discussions and replies:SPE 18397, SPE 20007, SPE 20009

Fast hybrid 3D imaging by small tip angle excitation

We presented two tasks, spatial interval discrimination and displacement detection, simultaneously in the same location at various eccentricities. The subject was to solve (i) only the spatial interval task; (ii) only the displacement task; or (iii) both tasks simultaneously. With 500 msec stimulus duration, and using the method of spatial scaling, the E2 value (the eccentricity at which stimulus size has to be doubled to maintain performance level) was found to be 0.17–0.39 deg for spatial interval discrimination and 1.0–1.2 deg for displacement detection. These values remained unaffected whether the subject solved one task or two tasks simultaneously. This finding was confirmed using a shorter, 50 msec stimulus duration. As there is no interference between tasks, the mechanisms solving the tasks appear to be functionally independent i.e., operating in parallel at all eccentricities.

Semantic and cognitive development in 15- to 21-month-old children.

ABSTRACTRecent studies suggest a specific relationship between the acquisition of the word ‘gone’ and the development of the object concept. A longitudinal study investigated whether there is a similar relationship between the acquisition of words that encode success and failure, such as no, uh-oh and there, and the development of means–ends skills. A cross-sectional study investigated both these relationships. The results suggest that children acquire the word gone after they solve simple invisible displacement tasks but before they solve serial invisible displacement tasks. They also show that children acquire success/failure words after they use insight to solve the problem of the string but before they use insight to solve more difficult means–ends problems. These sequences cannot be explained in terms of age, general cognitive development or general linguistic development. It is argued that gone encodes a concept related to the concepts that underlie success on invisible displacement tasks, and that success/failure words encode concepts related to the concepts that underlie the development of insight. Children seem to acquire words that encode concepts they have just developed or are in the process of developing. These results suggest that there are strong and specific links between the acquisition of particular types of meanings and particular cognitive achievements. Several alternative explanations for these early links between semantic and conceptual development are proposed.

The Effects of Differential Criteria on the Assessment of Cognitive-Linguistic Relationships

SMOLAK, LINDA, and LEVINE, MICHAEL P. The Effects of Differential Criteria on the Assessment of Cognitive-Linguistic Relationships. CHILD DEVELOPMENT, 1984, 55, 973-980. Many investigations of Piaget's model of cognitive-linguistic relationships have used methods that are inconsistent with Piagetian theory. This study examined 3 common methodological problems: (1) the definition and scoring of stage 6 object permanence, (2) the definitions of representational language and symbolic play, and (3) the use of correlations for data analysis. 40 children, 1-3 years old, were tested on 5 invisible displacement tasks, symbolic play level, and representational language. When Piaget's operational definitions of nonlinguistic and linguistic representation were used, presentation of the data in contingency tables supported his contention that nonlinguistic representation precedes linguistic representation. This relationship was unaffected by liberal versus conservative scoring of object-permanence task. When operational definitions developed by other researchers were used, the relationships were underestimated. Collectively, the results suggest that use of Piaget's operational definitions and restricted use of correlational techniques are essential for a meaningful evaluation of his theory. This study provides some guidelines for defining and analysing linguistic and nonlinguistic representation in future investigations of Piaget's model.

The acquisition of gone and the development of the object concept.

ABSTRACTThe relationship between the acquisition of gone and the development of the object concept is investigated. Children acquire gone at the same time that they solve serial invisible displacement tasks, in a transitional period in the development of the object concept. According to a ‘neo-piagetian’ account of the object concept, children move from using specific rules to predict the reappearance of objects, to using a general theory of object movements during this period. The children's uses of gone suggest that gone encodes the fact that the child does not perceive an existing object. This concept is an essential component of the new theory of objects developed in this period. Children seem to acquire gone when they are in the midst of developing the concept that gone encodes, which may explain why they acquire the word in this period. In this case, conceptual development does not precede semantic development; rather, conceptual and semantic development appear to proceed simultaneously.

Perceptual Trace Development during Motor Skill Acquisition in Stroke Patients

The hypothesis that stroke patients could learn a perceptual motor skill by developing a strong perceptual trace with practice was tested. Ten spastic stroke patients and sixteen normal subjects were observed while they learned a novel self-paced linear displacement task. The criterion movement was the displacement of an object with the affected leg (in the case of stroke patients) and left leg (in normal subjects), to a designated target. Visual, auditory, kinesthetic as well as knowledge of result information was available to the subjects. The results showed that stroke patients were able to reduce their movement errors as a function of practice by developing and strengthening their perceptual trace. This technique may be adapated for the modification of the motor behaviour of stroke patients.

Search Behavior on Multi-Choice Hiding Tasks: Evidence for an Objective Conception of Space in Infancy

Nineto 10-month old infants were presented with a series of visible displacement hiding trials at a first location (A), and, subsequently, at a second location (B). Infants had to choose among 3, 5, or 6 salient alternative search locations on each trial. Infants seldom searched perseveratively during B-hiding trials, regardless of the number of alternative search locations presented. Instead, infant search attempts tended to cluster around the currently correct location during Aand B-hiding trials on all apparatuses. These findings suggest that infants do not err on visible displacement tasks because they (a) link objects with previous action-locations, (b) rely upon egocentric spatial reference systems, or (c) confuse different hiding locations as a result of a specific form of retrieval competition from the previous hiding location. The results are discussed as evidence for a memory explanation of infant search behavior which contends that infants comprehend the objective nature of spatial relationships, but are less effective information processors than older individuals.

Motor impairment following blockade of the infraorbital nerve: implications for the use of anesthetization techniques in speech research.

Infraorbital nerve blocks were performed bilaterally in three subjects as a partial test of the hypothesis that some portion of the motor innervation to the facial muscles is provided in the trigeminal nerve. To ascertain the influence of this anesthetic procedure, the magnitude and rate of upper lip displacement (for speech and nonspeech tasks), the magnitude and rate of upper lip depression force, and diadochokinetic rate were transduced and recorded, both pre- and postanesthesia. All measures, along with bilateral muscle action potentials from orbicularis oris superior obtained for all force and displacement tasks, were reduced in magnitude as a function of the anesthetic condition. These findings, along with results from previous speech anesthetic studies, were interpreted to suggest that anesthesia of the infraorbital nerve produces measurable, if not substantial motor weakness in the supraoral musculature. The implications for previous studies, where anesthesia techniques have been employed, are discussed.

Higher Processes in Motor Learning

A linear displacement task was used to study the effects of post-KR verbal activity and the time of its introduction in the learning process on the acquisition of a simple discrete motor task. The temporal occurrence of the interpolated act was systematically varied (3 and 10 sec. immediately following KR). Reading polysyllables during the post-KR delay interval interfered with the learning process. Interference occurred whether the post-KR delay interval lasted 3 or 10 sec.

Feedback and Practice as Variables in Error Detection and Correction

Adams' (1971) closed-loop theory has response-produced feedback and practice as determinants of the internal reference that is the learned basis of error detection and correction. Two experiments were conducted on error detection and correction in test of this assumption, using a linear displacement task. Amounts of feedback and practice were variables, and both were found to be effective in error detection and correction. The discussion was mainly in terms of the informativeness of feedback channels and what it means for motor behavior.