Speed has an effect on multiple-object tracking independently of the number of close encounters between targets and distractors

Multiple-object tracking (MOT) studies have shown that tracking ability declines as object speed increases. However, this might be attributed solely to the increased number of times that target and distractor objects usually pass close to each other (“close encounters”) when speed is increased, resulting in more target–distractor confusions. The present study investigates whether speed itself affects MOT ability by using displays in which the number of close encounters is held constant across speeds. Observers viewed several pairs of disks, and each pair rotated about the pair’s midpoint and, also, about the center of the display at varying speeds. Results showed that even with the number of close encounters held constant across speeds, increased speed impairs tracking performance, and the effect of speed is greater when the number of targets to be tracked is large. Moreover, neither the effect of number of distractors nor the effect of target–distractor distance was dependent on speed, when speed was isolated from the typical concomitant increase in close encounters. These results imply that increased speed does not impair tracking solely by increasing close encounters. Rather, they support the view that speed affects MOT capacity by requiring more attentional resources to track at higher speeds

Effectiveness of wheat soya blend supplementation during pregnancy and lactation on pregnancy outcomes and nutritional status of their infants at 6 months of age in Thatta and Sujawal districts of Sindh, Pakistan: A cluster randomized-controlled trial

Purpose: We aimed to assess the effectiveness of wheat soya blend plus (WSBP) provided during pregnancy and lactation on weight gain during pregnancy, reduction of low birthweight (LBW), and improvement in nutritional status in infants at 6 months of age in Thatta and Sujawal districts of Sindh, Pakistan.Methods: A cluster randomized-controlled trial was conducted in Thatta and Sujawal districts in Pakistan from August 2014 to December 2016. A total of 2030 pregnant women were enrolled in the study. These women and their infants were followed during pregnancy and first 6 months of life. Pregnant women received a monthly ration of 5 kg (i.e., 165 g/day) of WSB + during pregnancy and the first 6 months of their lactation period.Results: There was no difference in weight gain during pregnancy between the intervention and control groups (n = 496, 326.7 g/week 95% CI 315.2-338.1 vs. (n = 507, 306.9 g/week, 95% CI 279.9-333.9 P = 0.192), after adjustment with different factors. The reduction in the prevalence of LBW was not different between intervention and control groups (n = 325, 34.0%, 95% CI 31.7-36.4, vs. (n = 127, 34.3%, 95% CI 27.2-41.5, P = 0.932). Significant reductions in risk of stunting (n = 1319 RR 0.85, 95% CI 0.73-0.99, P = 0.041), wasting (n = 1330 RR 0.77, 95% CI 0.65-0.91, P = 0.003), and underweight (n = 1295 RR 0.77, 95% CI 0.69-0.87, P \u3c 0.001) were observed in infants at 6 months of age in the intervention as compared to the control group. However, no difference was noted on reduction in the risk of stunting among infants at 6 months of age in the intervention and control group (n = 1318 RR 0.91, 95% CI 0.78-1.07, P = 0.253) after adjustment. A significant reduction in anemia was noted (n = 1328 RR 0.94, 95% CI 0.91-0.98, P = 0.002) in infants at 6 months of age in the intervention as compared to the control group in adjusted analysis.Conclusions: Provision of WSB + during pregnancy and the first 6 months of lactation is effective in reducing the risk of under nutrition and anemia in infants at 6 months of age. This study can potentially guide the government and donor agencies in investing in nutritional programmes, especially for pregnant and lactating women living in vulnerable settings

Protecting visual short-term memory during maintenance: Attentional modulation of target and distractor representations

In the presence of distraction, attentional filtering is a key predictor of efficient information storage in visual short-term memory (VSTM). Yet, the role of attention in distractor filtering, and the extent to which attentional filtering continues to protect information during post-perceptual stages of VSTM, remains largely unknown. In the current study, we investigated the role of spatial attention in distractor filtering during VSTM encoding and maintenance. Participants performed a change detection task with varying distractor load. Attentional deployment to target and distractor locations was tracked continuously by means of Steady-State Visual Evoked Potentials (SSVEPs). Analyses revealed that attention strongly modulated the amplitude of the second harmonic SSVEP response, with larger amplitudes at target compared to distractor locations. These attentional modulations commenced during encoding, and remained present during maintenance. Furthermore, the amount of attention paid to distractor locations was directly related to behavioral distractor costs: Individuals who paid more attention to target compared to distractor locations during VSTM maintenance generally suffered less from the presence of distractors. Together, these findings support an important role of spatial attention in distractor filtering at multiple stages of VSTM, and highlight the usefulness of SSVEPs in continuously tracking attention to multiple locations during VSTM