Age-related differences in saccadic indices of top-down guidance via short-term memory during visual search

Aging has  been  associated  with significant  declines  in  the  speed  and  accuracy  of visual search. These effects have been attributed partly to low-level (bottom-up) factors including  reductions  in  sensory  acuity  and  general  processing  speed.  Aging  is  also associated  with  changes  in  top-down  attentional  control,  but  the  impact  of  these  on search is less well understood. The current study investigated age-related differences in top-down attentional control by comparing the speed and accuracy of saccadic sampling in  the  presence  and  absence  of  top-down  information  about  target  color  in  young  (YA) and older (OA) observers. Displays contained an equal number of red and blue Landholt stimuli.   Targets   were   distinguished   from  distractors   by   a   unique   orientation   and observers reported the direction of the target’s gap on each trial. Single-target  cues signaled the color of the target with 100% validity. Dual-target cues indicated the target could   be   present   in   either   colored  subgroup.   The   results   revealed   reliable   group differences in the benefits associated with top-down information on single-compared to dual-target cues. On single-target searches, OA made significantly more saccades than YA to  stimuli  in  the  uncued  color  subset.  Single-target  cues  also  produced  a  smaller advantage  in  the  time  taken  to  fixate  the  target  in  OA  compared  to  YA.  These  results support  an  age-related decline in observers’ use of top-down  information  to  restrict sequences of saccades to a task-relevant subset of objects during visual search.</p

sj-docx-1-cqx-10.1177_19389655231214744 – Supplemental material for Disability Employment in the Hospitality Industry: A Systematic Literature Review

Supplemental material, sj-docx-1-cqx-10.1177_19389655231214744 for Disability Employment in the Hospitality Industry: A Systematic Literature Review by Ashokkumar Manoharan, Claire Hutchinson, Gerrit J. M. Treuren and Juan M. Madera in Cornell Hospitality Quarterly</p

Comparison of Logarithmic Reading Charts for Visual Assessment in Normally Sighted Participants

SIGNIFICANCE  Logarithmic reading charts provide standardized measures of reading performance. Here we show that existing charts provide equivalent assessments of visual aspects of reading that are in good agreement with traditional measures of visual acuity and seem uninfluenced by cognitive (linguistic) factors. PURPOSE  The aims of this study were to (1) determine the equivalence of logarithmic charts of sentence and word reading, (2) evaluate the relationship between reading chart performance and more traditional measures of visual assessment, and (3) establish the influence of linguistic factors on reading chart performance. METHODS  In a sample of 82 normally sighted participants, we determined performance on the reading measures (e.g., reading acuity, reading speed, critical print size) of the following logarithmic charts of sentence and word reading: The Colenbrander English Continuous Text Near Vision Card, Radner Reading Chart, Minnesota Reading Acuity Chart, and Smith-Kettlewell Reading Chart. In doing so, we compared performance on reading measures between charts and with performance on more traditional measures of visual assessment (uncrowded and crowded letter acuity, stereoacuity, accommodation) and cognitive measures of word knowledge and ability (Wechsler Adult Intelligence Scale Vocabulary Subtest, National Adult Reading Test). RESULTS  Factor analysis confirmed that performance on the reading measures (reading acuity, reading speed, critical print size) was equivalent across charts. Reading test performance was also related to more traditional measures of vision, the most consistent of which were significant associations between reading acuity and acuity for single-letter optotypes. There were no significant associations between reading chart performance and cognitive measures of word knowledge and ability. CONCLUSIONS  The findings presented here suggest that logarithmic charts composed of sentences and words represent an alternative to traditional letter acuity testing. This is particularly the case for measures of reading acuity.</p

Retinal layer abnormalities as biomarkers of schizophrenia

Objective Schizophrenia is associated with several brain deficits, as well as visual processing deficits, but clinically-useful biomarkers are elusive. We hypothesised that retinal layer changes, non-invasively visualized using spectral-domain optical coherence tomography (SD-OCT), may represent a possible “window” to these abnormalities. Methods A Leica EnvisuTM SD-OCT device was used to obtain high-resolution central foveal B-scans in both eyes of 35 patients with schizophrenia and 50 demographically-matched controls. Manual retinal layer segmentation was performed to acquire individual and combined layer thickness measurements in three macular regions. Contrast sensitivity was measured at three spatial frequencies in a sub-group of each cohort. Differences were compared using adjusted linear models and significantly different layer measures in patients underwent Spearman Rank correlations with contrast sensitivity, quantified symptoms severity, disease duration and antipsychotic medication dose. Results Total retinal and photoreceptor complex thickness was reduced in all regions in patients (P<0.0001). Segmentation revealed consistent thinning of the outer nuclear layer (P<0.001) and inner segment layer (P<0.05), as well as a pattern of parafoveal ganglion cell changes. Low spatial frequency contrast sensitivity was reduced in patients (P=0.002) and correlated with temporal parafoveal ganglion cell complex thinning (R=0.48, P=0.01). Negative symptom severity was inversely correlated with foveal photoreceptor complex thickness (R=-0.54, P=0.001) and outer nuclear layer thickness (R=-0.47, P=0.005). Samani et al. 4 Conclusions Our novel findings demonstrate considerable retinal layer abnormalities in schizophrenia that are related to clinical features and visual function. With time, SD-OCT could provide easily-measurable biomarkers to facilitate clinical assessment and further our understanding of the disease

DataSheet2_A genome-wide association study of plasma concentrations of warfarin enantiomers and metabolites in sub-Saharan black-African patients.XLSX

Diversity in pharmacogenomic studies is poor, especially in relation to the inclusion of black African patients. Lack of funding and difficulties in recruitment, together with the requirement for large sample sizes because of the extensive genetic diversity in Africa, are amongst the factors which have hampered pharmacogenomic studies in Africa. Warfarin is widely used in sub-Saharan Africa, but as in other populations, dosing is highly variable due to genetic and non-genetic factors. In order to identify genetic factors determining warfarin response variability, we have conducted a genome-wide association study (GWAS) of plasma concentrations of warfarin enantiomers/metabolites in sub-Saharan black-Africans. This overcomes the issue of non-adherence and may have greater sensitivity at genome-wide level, to identify pharmacokinetic gene variants than focusing on mean weekly dose, the usual end-point used in previous studies. Participants recruited at 12 outpatient sites in Uganda and South Africa on stable warfarin dose were genotyped using the Illumina Infinium H3Africa Consortium Array v2. Imputation was conducted using the 1,000 Genomes Project phase III reference panel. Warfarin/metabolite plasma concentrations were determined by high-performance liquid chromatography with tandem mass spectrometry. Multivariable linear regression was undertaken, with adjustment made for five non-genetic covariates and ten principal components of genetic ancestry. After quality control procedures, 548 participants and 17,268,054 SNPs were retained. CYP2C9*8, CYP2C9*9, CYP2C9*11, and the CYP2C cluster SNP rs12777823 passed the Bonferroni-adjusted replication significance threshold (p 2 > 0.8) with CYP2C9*8 (n = 216) and rs12777823 (n = 8). Using a pharmacokinetic approach, we have shown that variants other than CYP2C9*2 and CYP2C9*3 are more important in sub-Saharan black-Africans, mainly due to the allele frequencies. In exploratory work, we conducted the first warfarin pharmacokinetics-related GWAS in sub-Saharan Africans and identified novel SNPs that will require external replication and functional characterization before they can be considered for inclusion in warfarin dosing algorithms.</p

DataSheet1_A genome-wide association study of plasma concentrations of warfarin enantiomers and metabolites in sub-Saharan black-African patients.zip

Diversity in pharmacogenomic studies is poor, especially in relation to the inclusion of black African patients. Lack of funding and difficulties in recruitment, together with the requirement for large sample sizes because of the extensive genetic diversity in Africa, are amongst the factors which have hampered pharmacogenomic studies in Africa. Warfarin is widely used in sub-Saharan Africa, but as in other populations, dosing is highly variable due to genetic and non-genetic factors. In order to identify genetic factors determining warfarin response variability, we have conducted a genome-wide association study (GWAS) of plasma concentrations of warfarin enantiomers/metabolites in sub-Saharan black-Africans. This overcomes the issue of non-adherence and may have greater sensitivity at genome-wide level, to identify pharmacokinetic gene variants than focusing on mean weekly dose, the usual end-point used in previous studies. Participants recruited at 12 outpatient sites in Uganda and South Africa on stable warfarin dose were genotyped using the Illumina Infinium H3Africa Consortium Array v2. Imputation was conducted using the 1,000 Genomes Project phase III reference panel. Warfarin/metabolite plasma concentrations were determined by high-performance liquid chromatography with tandem mass spectrometry. Multivariable linear regression was undertaken, with adjustment made for five non-genetic covariates and ten principal components of genetic ancestry. After quality control procedures, 548 participants and 17,268,054 SNPs were retained. CYP2C9*8, CYP2C9*9, CYP2C9*11, and the CYP2C cluster SNP rs12777823 passed the Bonferroni-adjusted replication significance threshold (p 2 > 0.8) with CYP2C9*8 (n = 216) and rs12777823 (n = 8). Using a pharmacokinetic approach, we have shown that variants other than CYP2C9*2 and CYP2C9*3 are more important in sub-Saharan black-Africans, mainly due to the allele frequencies. In exploratory work, we conducted the first warfarin pharmacokinetics-related GWAS in sub-Saharan Africans and identified novel SNPs that will require external replication and functional characterization before they can be considered for inclusion in warfarin dosing algorithms.</p