Some grips on the handle of a tool can be planned based on information directly available in the scene. Other grips, however, must be planned based on the final position of the hand. “End-state comfort” grips require an awkward or uncomfortable initial grip so as to later implement the action comfortably and efficiently. From a cognitive perspective, planning for end-state comfort requires a consistent representation of the entire action sequence, including the latter part, which is not based on information directly available in the scene. Many investigators have found that young children fail to demonstrate planning for end-state comfort and that adult-like performance does not appear until about 12 years of age. In two experiments, we used a hammering task that engaged children in a goal-directed action with multiple steps. We assessed end-state-comfort planning in novel ways by measuring children’s hand choice, grip choice, and tool implementation over multiple trials. The hammering task also uniquely allowed us to assess the efficiency of implementation. We replicated the previous developmental trend in 4-, 8-, and 12-year-old children with our novel task. Most important, our data revealed that 4-year-olds are in a transitional stage with several competing strategies exhibited during a single session. Preschoolers changed their grip within trials and across trials, indicating awareness of errors and a willingness to sacrifice speed for more efficient implementation. The end-state-comfort grip initially competes as one grip type among many, but gradually displaces all others. Children’s sensitivity to and drive for efficiency may motivate this change.

Purpose The aims of this retrospective study were to compare the results of recommended screening tests for hydroychloroquine related retinal toxicity and analyze disparities between the structural and functional findings. Methods Thirty four patients (31 women, 3 men) were included in the study. All were evaluated with standard automated perimetry using the 10-2 and/or 24-2 visual field program (Zeiss, Meditec), multifocal electroretinography (mfERG), spectral domain optical coherence tomography (SD-OCT), and short wavelength fundus autofluorescent imaging (SW-FAF). The results for the right eye from each patient were analyzed. Visual fields were classified as normal or abnormal based on pattern deviation plots, and mfERGs based on a comparison of R5 ring ratios to values from 20 controls. The SW-FAF images were examined for areas/rings of abnormal hypo- and/or hyperautofluorescence, and the SD-OCT line scans were classified as abnormal based on visual inspection and thickness measurements of the outer segment plus retinal pigment epithelial layer and total receptor layers compared to mean thicknesses from 35 controls. Results Fifteen patients had abnormal results on at least 1 test, however only 2 patients had abnormal results on all 4 tests. Excluding SW-FAF, 7 of the 15 had abnormal visual fields, mfERG ring ratios and SD-OCTs. The remaining 8 had either abnormal mfERGs and/or visual fields and normal SD-OCTs. We found no evidence of abnormal SD-OCTs in the presence of normal mfERG and visual field results. Conclusions The findings suggest that functional deficits precede structural changes seen on SD-OCT in these patients.

This work is licensed under Creative Commons Attribution 4.0 License AJBSR.MS.ID.000827 Short Communication