Errorless learning is superior to trial and error when learning a practical skill in rehabilitation: a randomized controlled trial.

OBJECTIVE: Errorless learning is an effective strategy for the cognitive rehabilitation of memory impairment, but there is little evidence to support its use for skill learning. This preliminary study investigates whether errorless learning is superior to treatment as usual (trial and error), when teaching people with amputations and comorbid risk of vascular cognitive impairment to fit a prosthetic limb. DESIGN: A randomized control design. SETTING: A regional limb-fitting clinic at the West of Scotland Mobility and Rehabilitation Centre in Glasgow. PARTICIPANTS: Thirty adults with transtibial amputations, recruited from a regional limb-fitting clinic. Of these 42% were cognitively impaired. INTERVENTION: Random assignment to an errorless learning intervention (n = 15) or a treatment as usual control (n = 15). There were five training trials within a single session. Participants were then asked to fit their limb without assistance. MAIN MEASURES: Performance was scored from videotape recording of the first occasion when the participant attempted to fit their limb without assistance. Addenbrookes Cognitive Examination-Revised (ACE-R) was used to assess general cognitive functioning. RESULTS: The errorless learning group remembered more correct steps (mean 90.9, SD 12.1) than the control group (77.9; 8.4; P<0.001) and made fewer errors (mean 0.93, SD 1.3) than controls (2.1; 0.95); P =0.002). CONCLUSIONS: Errorless learning can benefit people with amputations in learning the practical skill of fitting a prosthetic limb. Further study that includes follow-up is warranted.

Dual task performance in early Alzheimer's disease, amnestic mild cognitive impairment and depression.

BACKGROUND: The dual task paradigm (Baddeley et al. 1986; Della Sala et al. 1995) has been proposed as a sensitive measure of Alzheimer's dementia, early in the disease process. METHOD: We investigated this claim by administering the modified dual task paradigm (utilising a pencil-and-paper version of a tracking task) to 33 patients with amnestic mild cognitive impairment (aMCI) and 10 with very early Alzheimer's disease, as well as 21 healthy elderly subjects and 17 controls with depressive symptoms. All groups were closely matched for age and pre-morbid intellectual ability. RESULTS: There were no group differences in dual task performance, despite poor performance in episodic memory tests of the aMCI and early Alzheimer's disease groups. In contrast, the Alzheimer patients were specifically impaired in the trail-making test B, another commonly used test of divided attention. CONCLUSIONS: The dual task paradigm lacks sensitivity for use in the early differential diagnosis of Alzheimer's disease.

Simulation of cell proliferation in mouse oral epithelium, and the action of epidermal growth factor: evidence for a high degree of synchronization of the stem cells.

Computer simulation has been carried out to help to determine the cell-proliferative mechanisms underlying data gathered from a double-labelling experiment on the dorsal tongue of the mouse. Good fits to the data have been obtained by assuming that there is a high degree of synchrony in the stem cells, which have a 24-h cell cycle time, and that daughters of these cells undergo two further divisions, with mean cell cycle times of 48 h, before differentiating. This results in one-seventh of proliferative cells being stem cells, which ties in well with the concept of epidermal proliferative units. There is no need to assume that S-phase duration changes diurnally. The administration of epidermal growth factor seems to increase the degree of synchrony. In such systems, the influx to S-phase and the efflux from it have very sudden short peaks, which it is impossible to observe unless observations are taken very frequently. There are therefore implications for the designs of experiments that attempt to study diurnal rhythms or the effect of factors that disturb the normal proliferative pattern of cells.

A new method for estimating population doubling time of vertebrate cells.

Based upon the fact that the amount of DNA doubles after each cycle, a technique was developed in which the population doubling time for cell cultures was determined from the ratio of its DNA content to [3H]thymidine incorporation under conditions in which cell numbers cannot be readily determined. This technique may be useful in determining what proportion the sample is of the total cell population.

CELLSIM and CELLGROW: tools for cell kinetic modeling.

Cell kinetics relates to the movement and proliferation of cells through their generative cycle and to how this cycle is affected by drugs, radiation, and other types of treatment. Two stochastic simulation systems have been developed to model this behavior.

Design history of a cell kinetics simulation language.

The field of cell kinetics relates to the movement and proliferation of cells through their generative cycle and to how this cycle is affected by chemotherapy treatment. CELLSIM is a discrete, digital simulation language for modeling this process. The language is interpretive, with the interpreter written in FORTRAN. It has been implemented on a wide variety of computer systems. The language features dynamic memory allocation, arithmetic string manipulation, and the capability of generating random variates from a number of probability distributions. The language has continued to evolve as the needs and desires of cancer researchers have been discovered. Its early use was only in experimental environments, but it is now being used to prescribe actual chemotherapy treatments.