No abstract

Little attention is paid to the issue of errors in nursing practice. Staff are reluctant to discuss or publicize them. However, as clinical audit and quality management become more important and established in the health service, there is now a greater need to investigate and monitor the incidence of errors. The purpose of this study was to examine the causes and consequences of errors as well as the potential for errors to initiate changes in practice. One hundred and twenty-nine nurses answered a 22-item questionnaire relating to an error they had made. Nurses reported that the most common causes of errors were lack of knowledge or information, work overload, stressful atmosphere and lack of support from senior staff. Nurses were found to have recourse to a number of coping strategies in the aftermath of the error. Accepting responsibility and planful problem-solving were found to lead to positive changes in practice, whereas distancing and self-controlling strategies were associated with defensive changes, particularly with a tendency not to divulge the error. The findings also showed that errors had the potential to effect learning. The study suggests the need for staff to be encouraged to accept responsibility for their error within the framework of support. Strategies should be developed so that errors can be managed in a more constructive manner.

No abstract

A plaid pattern is formed when two sinusoidal gratings of different orientations are added together. Previous work has shown that V1 neurons selectively encode the direction and orientation of the component gratings in a moving plaid but not the direction of the plaid itself (Movshon et al. 1985). We recorded the responses of 49 direction-selective neurons to moving gratings and plaid patterns in area V1 of the anesthetized marmoset monkey (Callithrix jacchus). The responses of V1 neurons to rectangular patches of varying lengths and widths containing gratings of optimal spatial frequency were used to measure size and aspect ratio of the receptive-field subunits. We measured responses to plaid patterns moving in different directions and graded the magnitude of the response to the direction of motion of the plaid and the response to the direction of motion of the component gratings. We found significant correlations between receptive-field structure and the type and strength of its response to moving plaid patterns. The strength of pattern and component responses was significantly correlated with the interrelated properties of direction tuning width (Spearman's r = 0.82, P < 0.001), and receptive-field subunit aspect ratio (Spearman's r = -0.79, P < 0.001). Neurons with broad direction tuning and short, wide receptive-field subunits gave their greatest response when the plaid moved in their preferred direction. Conversely, neurons with narrow direction tuning and long, narrow receptive-field subunits gave their greatest responses when the plaid moved in a direction such that one of its components moved in the preferred direction.