Postdictive confidence (but not predictive confidence) predicts eyewitness memory accuracy.

If testing conditions are uncontaminated, confidence at test reliably predicts eyewitness memory accuracy. Unfortunately, information about eyewitness postdictive confidence (at the time of the identification test) is frequently unavailable or not well documented. In cases where postdictive confidence is unavailable, a useful indicator of eyewitness accuracy might be an eyewitness's predictive confidence made shortly after the event. How do the accuracy of predictive and postdictive confidence judgments compare; and do variables reported to affect memory (e.g. exposure duration, face race) affect the reliability of the confidence-accuracy relationship for predictive and postdictive judgments? In two experiments, we tested the accuracy of memory predictions (immediate and delayed judgments of learning [JOLs]) and postdictions (confidence) for same- and cross-race faces. Although delayed high JOLs were indicative of higher recognition memory accuracy than delayed low JOLs for both same- and cross-race faces, the accuracy of even high predictive JOLs was objectively low. Postdictive confidence was a far stronger indicator of memory accuracy than predictive JOLs; high postdictive confidence was indicative of high accuracy; and this was true for both same- and cross-race recognition memory.

Evidence for a confidence-accuracy relationship in memory for same- and cross-race faces.

Discrimination accuracy is usually higher for same- than for cross-race faces, a phenomenon known as the cross-race effect (CRE). According to prior research, the CRE occurs because memories for same- and cross-race faces rely on qualitatively different processes. However, according to a continuous dual-process model of recognition memory, memories that rely on qualitatively different processes do not differ in recognition accuracy when confidence is equated. Thus, although there are differences in overall same- and cross-race discrimination accuracy, confidence-specific accuracy (i.e., recognition accuracy at a particular level of confidence) may not differ. We analysed datasets from four recognition memory studies on same- and cross-race faces to test this hypothesis. Confidence ratings reliably predicted recognition accuracy when performance was above chance levels (Experiments 1, 2, and 3) but not when performance was at chance levels (Experiment 4). Furthermore, at each level of confidence, confidence-specific accuracy for same- and cross-race faces did not significantly differ when overall performance was above chance levels (Experiments 1, 2, and 3) but significantly differed when overall performance was at chance levels (Experiment 4). Thus, under certain conditions, high-confidence same-race and cross-race identifications may be equally reliable.

Targeted exome sequencing for mitochondrial disorders reveals high genetic heterogeneity.

BACKGROUND: Mitochondrial disorders are difficult to diagnose due to extreme genetic and phenotypic heterogeneities. METHODS: We explored the utility of targeted next-generation sequencing for the diagnosis of mitochondrial disorders in 148 patients submitted for clinical testing. A panel of 447 nuclear genes encoding mitochondrial respiratory chain complexes, and other genes inducing secondary mitochondrial dysfunction or that cause diseases which mimic mitochondrial disorders were tested. RESULTS: We identified variants considered to be possibly disease-causing based on family segregation data and/or variants already known to cause disease in twelve genes in thirteen patients. Rare or novel variants of unknown significance were identified in 45 additional genes for various metabolic, genetic or neurogenetic disorders. CONCLUSIONS: Primary mitochondrial defects were confirmed only in four patients indicating that majority of patients with suspected mitochondrial disorders are presumably not the result of direct impairment of energy production. Our results support that clinical and routine laboratory ascertainment for mitochondrial disorders are challenging due to significant overlapping non-specific clinical symptoms and lack of specific biomarkers. While next-generation sequencing shows promise for diagnosing suspected mitochondrial disorders, the challenges remain as the underlying genetic heterogeneity may be greater than suspected and it is further confounded by the similarity of symptoms with other conditions as we report here.

Preliminary investigation of the use of newborn dried blood spots for screening pyridoxine-dependent epilepsy by LC-MS/MS.

α-AASA and P6C were measured retrospectively in original newborn DBS of five patients with PDE using a LC-MS/MS method we developed previously. Both α-AASA and P6C were elevated markedly in the three newborn DBS stored at -20°C. At room temperature, α-AASA and P6C in DBS appeared stable for 3 days and then decreased by up to 70% after 14 days but remained much higher than control, indicating newborn screening for PDE is feasible.

Top hat wound configuration for penetrating keratoplasty using the femtosecond laser: a laboratory model.

PURPOSE: To evaluate the mechanical stability and induced astigmatism of a modified multiplanar "top hat" wound configuration for full-thickness penetrating keratoplasty (PK) using the femtosecond laser as compared with PK in a laboratory model. METHODS: Eight human corneoscleral rims were mounted on an artificial anterior chamber. Four samples were assigned to the traditional PK group. Four samples underwent full-thickness keratoplasty with the femtosecond laser: a 9.0-mm cylindrical cut was made from the anterior chamber into the stroma, followed by a ring-shaped (outer diameter 9.0 mm, inner diameter 7.0 mm) horizontal lamellar resection at two-thirds corneal depth and a 7.0-mm cylindrical cut from the lamellae to the corneal surface. Mechanical stability was evaluated after placement of the cardinal sutures and the running sutures. RESULTS: In the "top hat" PK group, wound leakage occurred at 19 +/- 3.36 mm Hg after placement of the cardinal sutures and at 86.25 +/- 9.74 mm Hg after placement of the running sutures. In the traditional PK group, leakage occurred at 0 +/- 0 mm Hg and 76.25 +/- 20.98 mm Hg after placement of the cardinal sutures and running sutures, respectively. Both techniques induced steepening of the corneal curvature postop. The modified wound group showed a mean change in average K of 3.43 +/- 3.62 D, whereas the traditional PK group showed a mean change in average K of 3.21 +/- 6.67 D. CONCLUSION: The femtosecond laser-produced "top hat" wound configuration for PK was found to be more mechanically stable than that produced by the traditional method.

Femtosecond laser posterior lamellar keratoplasty: a laboratory model.

PURPOSE: To evaluate feasibility of femtosecond laser application in posterior lamellar keratoplasty. METHODS: To evaluate the laser's effectiveness through opaque corneas, anterior corneal caps were resected from opaque corneas induced with 80% acetone solution. To evaluate the femtosecond laser posterior lamellar keratoplasty surgical procedure, human corneoscleral rims were mounted on an artificial anterior chamber. After corneal pachymetry, the femtosecond laser was used to create a 6-mm-diameter, 200-microm-thick endostromal lenticule. Access to the lenticule was provided by a small perilimbal surface opening, also created by the laser. The lenticule was removed using a pair of corneal forceps. A donor lenticule of similar dimensions was created, its endothelial surface coated with viscoelastic, inserted, and positioned on the recipient bed. Two sutures were placed to seal the small surface opening. RESULTS: The femtosecond laser produced an effective and smooth dissection through opaque corneas even at deeper settings. Graft transplantation was fairly simple and effective. CONCLUSION: Femtosecond laser posterior lamellar keratoplasty is a procedure that may provide an alternative to penetrating keratoplasty or the technically challenging manual posterior lamellar keratoplasty.