A Pediatric Cervical Spine Clearance Guideline Leads to Fewer Unnecessary Computed Tomography Scans and Decreased Radiation Exposure.

OBJECTIVES: Physical examination and computed tomography (CT) are useful to rule out cervical spine injury (CSI). Computed tomography scans increase lifetime cancer risk in children from radiation exposure. Most CSI in children occur between the occiput and C4. We developed a cervical spine (C-spine) clearance guideline to reduce unnecessary CTs and radiation exposure in pediatric trauma patients. METHODS: A pediatric C-spine clearance guideline was implemented in September 2018 at our Level 2 Pediatric Trauma Center. Guidance included CT of C1 to C4 to scan only high-yield regions versus the entire C-spine and decrease radiation dose. A retrospective cohort study was conducted comparing preguideline and postguideline of all pediatric trauma patients younger than 8 years screened for CSI from July 2017 to December 2020. Primary endpoints included the following: number of full C-spine and C1 to C4 CT scans and radiation dose. Secondary endpoints were CSI rate and missed CSI. Results were compared using χ 2 and Wilcoxon rank-sum test with P < 0.05 significant. RESULTS: The review identified 726 patients: 273 preguideline and 453 postguideline. A similar rate of total C-spine CTs were done in both groups (23.1% vs 23.4%, P = 0.92). Full C-spine CTs were more common preguideline (22.7% vs 11.9%, P < 0.001), whereas C1 to C4 CT scans were more common post-guideline (11.5% vs 0.4%, P < 0.001). Magnetic resonance imaging utilization and CSIs identified were similar in both groups. The average radiation dose was lower postguideline (114 vs 265 mGy·cm -1 ; P < 0.001). There were no missed CSI. CONCLUSIONS: A pediatric C-spine clearance guideline led to increasing CT of C1 to C4 over full C-spine imaging, reducing the radiation dose in children. LEVEL OF EVIDENCE: Level IV, therapeutic.

BIG Kids: Application of a modified brain injury guideline in a pediatric trauma center.

BACKGROUND: Brain Injury Guidelines (BIG) were developed to stratify traumatic brain injuries (TBIs) by severity to decrease unnecessary CT imaging and neurosurgical consultation in low-risk cases. This study evaluated the potential effect of a modified pediatric BIG (pBIG) algorithm would have on resource utilization. METHODS: Isolated TBIs (<18 years) were queried from our Pediatric Trauma Registry from 2017 to 2020. Injuries were classified as mild (pBIG 1), moderate (pBIG 2), or severe (pBIG 3) based on neurologic status, skull fractures, size, and the number of bleeds. Modifications from the institutional adult algorithm were upgrading <4 mm epidural hematomas to pBIG 2 and eliminating interfacility transfer as a pBIG 2 criteria. The proposed pBIG 1 and 2 care plans do not include routine repeat CTs or neurosurgical consultation. RESULTS: A total of 314 children with a mean age of 4.9 years were included. Skull fractures (213, 68%) and subdural hematomas (162, 52%) were the most common injuries. 89 (28%) children had repeat head CTs (2 (7%) pBIG 1, 26 (25%) pBIG 2, 61 (34%) pBIG 3). Neurosurgical consultation was obtained in 306 (98%), with 50 (16%) requiring intervention (1 (1%) pBIG 2 and 49 (27%) pBIG 3). Following the proposed pBIG would decrease neurosurgical consults to 181 (58%) and repeat CTs to 63 (20%). Following the algorithm, 91 (29%) kids would have been admitted to a higher level of care and 45 (14.3%) to a lower level. CONCLUSIONS: Implementation of our pBIG algorithm would decrease neurosurgery consults (40% reduction) and repeat head CTs (29% reduction).

Reach endpoint errors do not vary with movement path of the proprioceptive target.

Previous research has shown that reach endpoints vary with the starting position of the reaching hand and the location of the reach target in space. We examined the effect of movement direction of a proprioceptive target-hand, immediately preceding a reach, on reach endpoints to that target. Participants reached to visual, proprioceptive (left target-hand), or visual-proprioceptive targets (left target-hand illuminated for 1 s prior to reach onset) with their right hand. Six sites served as starting and final target locations (35 target movement directions in total). Reach endpoints do not vary with the movement direction of the proprioceptive target, but instead appear to be anchored to some other reference (e.g., body). We also compared reach endpoints across the single and dual modality conditions. Overall, the pattern of reaches for visual-proprioceptive targets resembled those for proprioceptive targets, while reach precision resembled those for the visual targets. We did not, however, find evidence for integration of vision and proprioception based on a maximum-likelihood estimator in these tasks.

Proprioceptive localization of the left and right hands.

The present study examined the accuracy of proprioceptive localization of the hand using two paradigms. In our proprioceptive estimation paradigm, participants judged the position of a target hand relative to visual references, or their body's midline. Placement of the target hand was active (participants pushed a robot manipulandum along a constrained path) or passive (the robot manipulandum positioned participants' target hand). In our proprioceptive-guided reaching paradigm, participants reached to the unseen location of a hand; both the left and right hands served as the target hand and the reaching hand. In both paradigms, subjects were relatively good at estimating the location of each hand (i.e. relative to a reference marker or using a reach), with directional errors falling within 2 cm of the actual target location, and little variation across the workspace. In our proprioceptive estimation paradigm, biases when the target hand was passively placed were no larger than those made when the target hand was actively placed. Participants perceived their left hand to be more to the left than it actually was, and their right hand to be more rightward than it actually was, but with a similar error magnitude across target hands. In our reaching paradigm, participants' estimates of left hand location were deviated more leftwards than their estimates of right hand location, but showed a small but similar pattern of location-dependent reach errors across the two hands. Precision of estimates did not differ between the two hands or vary with target location for either paradigm.

Acute Sleep Restriction Has Differential Effects on Components of Attention.

Inadequate nightly sleep duration can impair daytime functioning, including interfering with attentional and other cognitive processes. Current models posit that attention is a complex function regulated by several separate, but interacting, neural systems responsible for vigilance, orienting, and executive control. However, it is not clear to what extent each of these underlying component processes is affected by sleep loss. The purpose of this study was to evaluate the effects of acute sleep restriction on these attentional components using the Dalhousie Computerized Attention Battery (DalCAB). DalCAB tasks were administered to healthy women (aged 19-25 years) on two consecutive mornings: once after a night with 9 h time in bed (TIB), and once again after either another night with 9 h TIB (control condition, n = 19) or after a night with 3 h TIB (sleep restriction condition, n = 20). Self-ratings of sleepiness and mood were also obtained following each sleep condition. Participants showed increases in self-reported sleepiness and fatigue after the second night only in the sleep restriction group. Sleep restriction primarily affected processing speed on tasks measuring vigilance; however, performance deficits were also observed on some measures of executive function (e.g., go/no-go task, flanker task, working memory). Tasks assessing orienting of attention were largely unaffected. These results indicate that acute sleep restriction has differential effects on distinct components of attention, which should be considered in modeling the impacts of sleep loss on the underlying attentional networks.

Methods for validating chronometry of computerized tests.

Determining the speed at which a task is performed (i.e., reaction time) can be a valuable tool in both research and clinical assessments. However, standard computer hardware employed for measuring reaction times (e.g., computer monitor, keyboard, or mouse) can add nonrepresentative noise to the data, potentially compromising the accuracy of measurements and the conclusions drawn from the data. Therefore, an assessment of the accuracy and precision of measurement should be included along with the development of computerized tests and assessment batteries that rely on reaction times as the dependent variable. This manuscript outlines three methods for assessing the temporal accuracy of reaction time data (one employing external chronometry). Using example data collected from the Dalhousie Computerized Attention Battery (DalCAB) we discuss the detection, measurement, and correction of nonrepresentative noise in reaction time measurement. The details presented in this manuscript should act as a cautionary tale to any researchers or clinicians gathering reaction time data, but who have not yet considered methods for verifying the internal chronometry of the software and or hardware being used.

Adoptive cell transfer therapy following non-myeloablative but lymphodepleting chemotherapy for the treatment of patients with refractory metastatic melanoma.

PURPOSE: We investigated the combination of lymphodepleting chemotherapy followed by the adoptive transfer of autologous tumor reactive lymphocytes for the treatment of patients with refractory metastatic melanoma. PATIENTS AND METHODS: Thirty-five patients with metastatic melanoma, all but one with disease refractory to treatment with high-dose interleukin (IL) -2 and many with progressive disease after chemotherapy, underwent lymphodepleting conditioning with two days of cyclophosphamide (60 mg/kg) followed by five days of fludarabine (25 mg/m(2)). On the day following the final dose of fludarabine, all patients received cell infusion with autologous tumor-reactive, rapidly expanded tumor infiltrating lymphocyte cultures and high-dose IL-2 therapy. RESULTS: Eighteen (51%) of 35 treated patients experienced objective clinical responses including three ongoing complete responses and 15 partial responses with a mean duration of 11.5 +/- 2.2 months. Sites of regression included metastases to lung, liver, lymph nodes, brain, and cutaneous and subcutaneous tissues. Toxicities of treatment included the expected hematologic toxicities of chemotherapy including neutropenia, thrombocytopenia, and lymphopenia, the transient toxicities of high-dose IL-2 therapy, two patients who developed Pneumocystis pneumonia and one patient who developed an Epstein-Barr virus-related lymphoproliferation. CONCLUSION: Lymphodepleting chemotherapy followed by the transfer of highly avid antitumor lymphocytes can mediate significant tumor regression in heavily pretreated patients with IL-2 refractory metastatic melanoma.

Measuring the Performance of Attention Networks with the Dalhousie Computerized Attention Battery (DalCAB): Methodology and Reliability in Healthy Adults.

Attention is an important, multifaceted cognitive domain that has been linked to three distinct, yet interacting, networks: alerting, orienting, and executive control. The measurement of attention and deficits of attention within these networks is critical to the assessment of many neurological and psychiatric conditions in both research and clinical settings. The Dalhousie Computerized Attention Battery (DalCAB) was created to assess attentional functions related to the three attention networks using a range of tasks including: simple reaction time, go/no-go, choice reaction time, dual task, flanker, item and location working memory, and visual search. The current study provides preliminary normative data, test-retest reliability (intraclass correlations) and practice effects in DalCAB performance 24-h after baseline for healthy young adults (n = 96, 18-31 years). Performance on the DalCAB tasks demonstrated Good to Very Good test-retest reliability for mean reaction time, while accuracy and difference measures (e.g., switch costs, interference effects, and working memory load effects) were most reliable for tasks that require more extensive cognitive processing (e.g., choice reaction time, flanker, dual task, and conjunction search). Practice effects were common and pronounced at the 24-h interval. In addition, performance related to specific within-task parameters of the DalCAB sub-tests provides preliminary support for future formal assessment of the convergent validity of our interpretation of the DalCAB as a potential clinical and research assessment tool for measuring aspects of attention related to the alerting, orienting, and executive control networks.

Oral fluid human immunodeficiency virus tests: improved access to diagnosis for infants in poorly resourced prevention of mother to child transmission programs.

BACKGROUND: Perinatal exposure of infants in low resource settings generates the bulk of pediatric human immunodeficiency virus (HIV) disease globally. The HIV status of these infants is established by testing serum for anti-HIV antibodies at 12 months of age in Prevention of Mother to Child Transmission (PMTCT) programs because polymerase chain reaction testing is unavailable. The diagnostic accuracy of 2 oral fluid (OF) HIV tests has not been previously evaluated in children. METHODS: A serum and 2 OF HIV tests were performed at 12 months of age in a cohort of 321 vertically exposed children in a prospective, longitudinal study at a secondary level hospital in Johannesburg, South Africa during a 14-month period preceding October 2003. The 3 HIV tests were performed independently of each other by personnel blinded to the child's true HIV infection status, the reference standard used for comparison. RESULTS: HIV testing was performed at a median age of 12.1 months. The true HIV infection status of 310 of 321 (97%) children was determined. In comparison with serum testing results, OF HIV tests reduced the percentage of children requiring repeat HIV tests from 45% to 8-12%. The abilities of OF and serum to predict an HIV-uninfected status were comparable with negative predictive values >99%. Interpretation of HIV tests in conjunction with simple clinical assessment further improved the predictive value of the test. CONCLUSIONS: OF HIV tests perform well in children and have the potential to increase accessibility and acceptability of HIV diagnosis for infants in the context of PMTCT programs in low resource settings.

Polymerase chain reaction for diagnosis of human immunodeficiency virus infection in infancy in low resource settings.

BACKGROUND: Diagnosis of human immunodeficiency virus (HIV) is essential for accessing treatment. Current HIV diagnostic protocols for infants require adaptation and validation before they can be implemented in the developing world. The timing and type of HIV assays will be dictated by country-specific circumstances and experience from similar settings. The performance of an HIV-1 DNA polymerase chain reaction (PCR) test, and in particular a single test at 6 weeks of age, in diagnosing HIV subtype C infection acquired in utero or peripartum was assessed. METHODS: A retrospective review of 1825 Amplicor HIV-1 DNA PCR version 1.5 tests performed between 2000 and 2004 in 2 laboratories in Johannesburg, South Africa on 769 effectively non-breast-fed infants from 3 clinically well characterized cohorts was undertaken. The HIV status of each infant was used as the standard against which the HIV PCR results were compared. RESULTS: The overall sensitivity and specificity of the HIV PCR test were 99.3 and 99.5% respectively. A single test was 98.8% sensitive and 99.4% specific in the 627 infants tested at 6 weeks of age (58 HIV-infected and 569 HIV-uninfected). Repeat testing of all positive HIV PCR tests minimized false positive results. CONCLUSIONS: In resource-poor settings where HIV PCR testing in an environment of good laboratory practice is feasible, a single 6-week HIV DNA PCR test can increase identification of HIV-infected children substantially from current levels. Further operational research on how best to implement and monitor such a diagnostic protocol in specific local settings, especially in breast-fed infants, is necessary.

Proprioceptive precision is impaired in Ehlers-Danlos syndrome.

It has been suggested that people with Ehlers-Danlos syndrome (EDS), or other similar connective tissue disorders, may have proprioceptive impairments, the reason for which is still unknown. We recently found that EDS patients were less precise than healthy controls when estimating their felt hand's position relative to visible peripheral reference locations, and that this deficit was positively correlated with the severity of joint hypermobility. We further explore proprioceptive abilities in EDS by having patients localize their non-dominant left hand at a greater number of workspace locations than in our previous study. Additionally, we explore the relationship between chronic pain and proprioceptive sensitivity. We found that, although patients were just as accurate as controls, they were not as precise. Patients showed twice as much scatter than controls at all locations, but the degree of scatter did not positively correlate with chronic pain scores. This further supports the idea that a proprioceptive impairment pertaining to precision is present in EDS, but may not relate to the magnitude of chronic pain.

Lessons learnt from enrolment and follow up of pregnant women and their infants in clinical trials in South Africa, a low-middle income country.

INTRODUCTION: Infectious causes are a significant contributor to morbidity and mortality in neonates and young infants. Immunization of pregnant women to protect the mother and/or her infant is gaining momentum due to the benefits of this strategy demonstrated in numerous implemented strategies (Maternal and Neonatal Tetanus Elimination Initiative) and clinical trials. Reluctance by regulators, participants and healthcare providers to include pregnant women in clinical trials is considerable, but reducing. Infectious disease burden, and therefore need for interventions to reduce morbidity and mortality in mothers and infants, is highest in low-middle income countries (LMIC), however, reliable background data on adverse pregnancy outcomes and lack of experience in clinical trials and community opinions on immunization during pregnancy are not well documented. METHODS: We used our experiences in conducting two clinical studies in pregnant women in South Africa to illustrate the challenges experienced and lessons learnt which may benefit others working in the maternal immunization field. RESULTS: Accurate gestational age assessment, which is essential for clinical trials, is challenging in LMIC due to limited access to early ultrasound examinations, and unreliable assessment by history (last menstrual period date) and physical examination (symphyseal-fundal height). Concomitant administration of recommended vaccines has previously been avoided in clinical trials; however, this limitation could impact the potentially beneficial interventions that participants can access during antenatal care. Women in LMIC have a higher burden of concomitant illnesses (e.g. HIV infection, malaria and anaemia) and adverse pregnancy outcomes (e.g. stillbirth) than pregnant women in higher income countries. Availability of local data is essential for safety monitoring committees to identify vaccine-related adverse event triggers. CONCLUSION: Immunization of pregnant women to reduce disease burden in them and their infants is promising, and women in high-risk settings should be included in trials (Clinical trial registry number: 'Study A': NCT01193920, 'Study B': NCT01888471).

Measuring the components of attention using the Dalhousie Computerized Attention Battery (DalCAB).

Using experimentally validated tests to measure the vigilance/alerting, orienting and executive control attention networks, we have developed a novel, theoretically driven battery for measuring attentional abilities, called the Dalhousie Computerized Attention Battery (DalCAB). The current study sought to examine the factor structure of the DalCAB as preliminary evidence for its validation as an assessment tool for the above-named attention networks. One hundred young, healthy adult participants (18 to 31 years) completed the DalCAB (simple reaction time, choice reaction time, dual task, go/no-go, visual search, vertical flanker, and item memory tasks). Exploratory factor analysis of task performance with promax rotation highlighted a 9-factor model, accounting for 54.66% of the shared variance. Factors 1, 2, and 5 are associated with measures reflecting the vigilance/alerting network (response speed, maintenance/preparation and consistency, respectively), Factor 3 is associated with the orienting network (searching measures). Factors 4, 6, 7, and 8 are associated with different aspects of the executive control network including: inhibition, working memory, filtering, and switching. The final factor is associated with vigilance/alerting (fatigue) and executive control (proactive interference). Our model provides preliminary evidence for the validation of our interpretation of the DalCAB as a measure of vigilance/alerting, orienting, and executive control attentional abilities, and contributes to the previously reported evidence for the validation of these tasks for measuring different aspects of attention. We also demonstrate the importance of each of the specific measures derived from the DalCAB tasks, and our results provide further behavioral evidence of the existence of multiple attention-related networks.

Acquisition of Streptococcus pneumoniae in South African children vaccinated with 7-valent pneumococcal conjugate vaccine at 6, 14 and 40 weeks of age.

BACKGROUND: Seven-valent pneumococcal conjugate vaccine (PCV7) was introduced into the South African immunization program using 6, 14 and 40 weeks dosing schedule (2+1), with no catch-up in older children since April 2009. We investigated pneumococcal colonization acquisition in children who received this schedule and also compared it to historical cohorts of PCV-naïve children (n=123 in 2007) and children who received a 3+1 PCV7 schedule (n=124 in 2005/06). METHODS: Two hundred and fifty children aged 6-12 weeks were enrolled from December 2009 to April 2010. Participants had nasopharyngeal swabs collected on eight occasions between enrolment and 2-years of age. Standard methods were undertaken for bacterial culture and Streptococcus pneumoniae were serotyped using the Quellung method. Pneumococcal and Staphylococcus aureus colonization in the present study was compared to colonization in two historical longitudinal cohorts. RESULTS: S. pneumoniae was identified in 1081 (61.4%) of 1761 swabs collected in the current cohort. Pneumococcal colonization peaked at 41-weeks of age (76.8%) and decreased to 62.8% by 2-years of age (p=0.002); PCV7-serotype colonization decreased during the same period from 28.6% to 15.6% (p=0.001). Children from the current cohort compared to PCV-naïve children were less likely to be colonized by PCV7-serotypes from 40-weeks to 2-years of age and acquired PCV7-serotypes less frequently. No differences in overall pneumococcal, PCV7-serotype and non-PCV7-serotype colonization or new serotype acquisitions were detected comparing the current cohort to the historical cohort who received the 3+1 PCV7 schedule. Staphylococcus aureus colonization was similar in all three cohorts. CONCLUSION: A 2+1 PCV7 schedule implemented in South Africa was temporally associated with reduced risk of vaccine-serotype colonization compared to historically unvaccinated children. Also, vaccine-serotype acquisition rate using the 2+1 schedule was similar to that in the 3+1 dosing cohort, suggesting that similar indirect protection against pneumococcal disease could be derived from either schedule in South Africa.

Directional interactions between current and prior saccades.

One way to explore how prior sensory and motor events impact eye movements is to ask someone to look to targets located about a central point, returning gaze to the central point after each eye movement. Concerned about the contribution of this return to center movement, Anderson et al. (2008) used a sequential saccade paradigm in which participants made a continuous series of saccades to peripheral targets that appeared to the left or right of the currently fixated location in a random sequence (the next eye movement began from the last target location). Examining the effects of previous saccades (n-x) on current saccade latency (n), they found that saccadic reaction times (RT) were reduced when the direction of the current saccade matched that of a preceding saccade (e.g., two left saccades), even when the two saccades in question were separated by multiple saccades in any direction. We examined if this pattern extends to conditions in which targets appear inside continuously marked locations that provide stable visual features (i.e., target "placeholders") and when saccades are prompted by central arrows. Participants completed 3 conditions: peripheral targets (PT; continuous, sequential saccades to peripherally presented targets) without placeholders; PT with placeholders; and centrally presented arrows (CA; left or right pointing arrows at the currently fixated location instructing participants to saccade to the left or right). We found reduced saccadic RT when the immediately preceding saccade (n-1) was in the same (vs. opposite) direction in the PT without placeholders and CA conditions. This effect varied when considering the effect of the previous 2-5 (n-x) saccades on current saccade latency (n). The effects of previous eye movements on current saccade latency may be determined by multiple, time-varying mechanisms related to sensory (i.e., retinotopic location), motor (i.e., saccade direction), and environmental (i.e., persistent visual objects) factors.

Changes in trunk orientation do not induce asymmetries in covert orienting.

We explored the effect of trunk orientation on responses to visual targets in five experiments, following work suggesting a disengage deficit in covert orienting related to changes in the trunk orientation of healthy participants. In two experiments, participants responded to the color of a target appearing in the left or right visual field following a peripheral visual cue that was informative about target location. In three additional experiments, participants responded to the location (left/right) of a target using a spatially compatible motor response. In none of the experiments did trunk orientation interact with spatial-cuing effects, suggesting that orienting behavior is not affected by the rotation of the body relative to the head. Theoretical implications are discussed.

Immunogenicity of seven-valent pneumococcal conjugate vaccine administered at 6, 14 and 40 weeks of age in South African infants.

BACKGROUND: The high cost of pneumococcal conjugate vaccine (PCV) and local epidemiological factors contributed to evaluating different PCV dosing-schedules. This study evaluated the immunogenicity of seven-valent PCV (PCV7) administered at 6-weeks; 14-weeks and 9-months of age. METHODS: 250 healthy, HIV-unexposed infants were immunized with PCV7 concurrently with other childhood vaccines. Serotype-specific anti-capsular IgG concentrations were measured one-month following the 1(st) and 2(nd) PCV-doses, prior to and two-weeks following the 3(rd) dose. Opsonophagocytic killing assay (OPA) was measured for three serotypes following the 2(nd) and 3(rd) PCV7-doses. Immunogenicity of the current schedule was compared to a historical cohort of infants who received PCV7 at 6, 10 and 14 weeks of age. RESULTS: The proportion of infants with serotype-specific antibody ≥ 0.35 µg/ml following the 2(nd) PCV7-dose ranged from 84% for 6B to ≥ 89% for other serotypes. Robust antibody responses were observed following the 3(rd) dose. The proportion of children with OPA ≥ 8 for serotypes 9V, 19F and 23F increased significantly following the 3(rd) PCV7-dose to 93.6%; 86.0% and 89.7% respectively. The quantitative antibody concentrations following the 2(nd) PCV7-dose were comparable to that after the 3(rd) -dose in the 6-10-14 week schedule. Geometric mean concentrations (GMCs) following the 3(rd) PCV7-dose were higher for all serotypes in this study compared to the historical cohort. CONCLUSIONS: The studied PCV7 dosing schedule induced good immune responses, including higher GMCs following the 3(rd-)dose at 9-months compared to when given at 14-weeks of age. This may confer longer persistence of antibodies and duration of protection against pneumococcal disease.

A task-dependent effect of memory and hand-target on proprioceptive localization.

We examine whether the task goal affects the accuracy and precision with which participants can localize an unseen hand. Proprioceptive localization was measured using three different tasks: two goal-directed movement tasks (reaching to and reproducing final hand-target location) and a perceptual estimation task in which participants judged the location of the hand-target relative to visual references. We also assessed whether proprioceptive localization in these different tasks is affected by localization from memory, the hand-target being localized (left or right) or the movement path of the proprioceptive target (9 paths, derived from combinations of starting and final hand-target positions). We found that participants were less precise when reaching from memory, but not when reproducing or estimating remembered final hand-target location. Participants also misperceived the felt location of their hands, judging their left hand to be more leftward and their right hand to be more rightward when reaching to and when estimating final hand-target location, but not when reproducing hand-target location. The movement path of the proprioceptive target did not affect localization, regardless of the task goal. Overall, localization seems poorer when proprioception is used to guide a reach with the opposite hand, particularly from memory, and best when merely reproducing the proprioceptive target site. This may have an important application in neuro-rehabilitation, whereby one task may better establish or re-establish important or failing sensory connections.

Memory for proprioceptive and multisensory targets is partially coded relative to gaze.

We examined the effect of gaze direction relative to target location on reach endpoint errors made to proprioceptive and multisensory targets. We also explored if and how visual and proprioceptive information about target location are integrated to guide reaches. Participants reached to their unseen left hand in one of three target locations (left of body midline, body midline, or right or body midline), while it remained at a target site (online), or after it was removed from this location (remembered), and also after the target hand had been briefly lit before reaching (multisensory target). The target hand was guided to a target location using a robot-generated path. Reaches were made with the right hand in complete darkness, while gaze was varied in one of four eccentric directions. Horizontal reach errors systematically varied relative to gaze for all target modalities; not only for visually remembered and online proprioceptive targets as has been found in previous studies, but for the first time, also for remembered proprioceptive targets and proprioceptive targets that were briefly visible. These results suggest that the brain represents the locations of online and remembered proprioceptive reach targets, as well as visual-proprioceptive reach targets relative to gaze, along with other motor-related representations. Our results, however, do not suggest that visual and proprioceptive information are optimally integrated when coding the location of multisensory reach targets in this paradigm.

The horizon line, linear perspective, interposition, and background brightness as determinants of the magnitude of the pictorial moon illusion.

A total of 110 undergraduate students participated in a series of three experiments that explored the magnitude of the moon illusion in pictures. Experiment 1 examined the role of the number and salience of depth cues and background brightness. Experiment 2 examined the role of the horizon line, linear perspective, interposition, and background brightness. In Experiment 3, comparative distance judgments of the moon as a function of linear perspective, interposition, and the size of the standard moon were obtained. The magnitude of the moon illusion increased as a function of the number and salience of depth cues and changes in background brightness. Experiment 2 failed to support the role of the horizon line in affecting the illusion. Experiment 3 provided additional support for the illusory distance component of the moon illusion.