Categorical perception for unfamiliar faces. The effect of covert and overt face learning

Robust findings show that categorical perception (CP) occurs in identification of familiar faces. CP has also been observed for unfamiliar morphed faces after sufficient learning of the original, unmorphed faces has taken place. We previously suggested that CP arises when the activation of inconsistent visual and verbal representations creates a conflict between perceptual and category information. In the present study, we conducted two experiments in which the endpoint faces of an unfamiliar morphed continuum were presented in either a covert training regime (famous vs. nonfamous judgments) or an overt training regime (previously seen vs. unseen judgments). In both experiments, participants' reaction times to repeated targets decreased relative to reaction times to control items during training. After overt training, CP was observed for the previously unfamiliar faces. No CP was observed for covertly trained faces. We conclude that individual faces must be explicitly categorized before CP can be established for the morphed continuum between them.

Color categories are not universal: replications and new evidence from a stone-age culture

The authors sought to replicate and extend the work of E. Rosch Heider (1972) on the Dani with a comparable group from Papua, New Guinea, who speak Berinmo, which has 5 basic color terms. Naming and memory for highly saturated focal, non-focal, and low-saturation stimuli from around the color space were investigated. Recognition of desaturated colors was affected by color vocabulary. When response bias was controlled, there was no recognition advantage for focal stimuli. Paired-associate learning also failed to show an advantage for focal stimuli. Categorical Perception effects for both English and Berinmo were found, but only at the boundaries of existing linguistic categories. It is concluded that possession of linguistic categories facilitates recognition and influences perceptual judgments.

The categorical perception of colors and facial expressions: the effect of verbal interference

A series of five experiments examined the categorical perception previously found for color and facial expressions. Using a two-alternative forced-choice recognition memory paradigm, it was found that verbal interference selectively removed the defining feature of categorical perception. Under verbal interference, there was no longer the greater accuracy normally observed for cross-category judgments relative to within-category judgments. The advantage for cross-category comparisons in memory appeared to derive from verbal coding both at encoding and at storage. It thus appears that while both visual and verbal codes may be employed in the recognition memory for colors and facial expressions, subjects only made use of verbal coding when demonstrating categorical perception.

Color categories are not universal: replications and new evidence from a stone-age culture

The authors sought to replicate and extend the work of E. Rosch Heider (1972) on the Dani with a comparable group from Papua, New Guinea, who speak Berinmo, which has 5 basic color terms. Naming and memory for highly saturated focal, non-focal, and low-saturation stimuli from around the color space were investigated. Recognition of desaturated colors was affected by color vocabulary. When response bias was controlled, there was no recognition advantage for focal stimuli. Paired-associate learning also failed to show an advantage for focal stimuli. Categorical Perception effects for both English and Berinmo were found, but only at the boundaries of existing linguistic categories. It is concluded that possession of linguistic categories facilitates recognition and influences perceptual judgments.

Similarity and categorisation: neuropsychological evidence for a dissociation in explicit categorisation tasks

A series of experiments are reported on a patient (LEW) with difficulties in naming. Initial findings indicated severe impairments in his ability to freesort colours and facial expressions. However, LEW's performance on other tasks revealed that he was able to show implicit understanding of some of the classic hallmarks of categorical perception; for example, in experiments requiring the choice of an odd-one-out, the patient chose alternatives dictated by category rather than by perceptual distance. Thus, underlying categories appeared normal and boundaries appeared intact. Furthermore, in a two-alternative forced-choice recognition memory task, performance was worse for within-category decisions than for cross-category decisions. In a replication of the study of Kay and Kempton [Kay, P., Kempton, W., 1984. What is the Sapir-Whorf hypothesis? American Anthropologist 86, 65-78], LEW showed that his similarity judgements for colours could be based on perceptual or categorical similarity according to task demands. The consequences for issues concerned with perceptual categories and the relationship between perceptual similarity and explicit categorisation are considered; we argue for a dissociation between these kinds of judgements in the freesort tasks. LEW's inability to make explicit use of his intact (implicit) knowledge is seen as related to his language impairment.

Clinical process improvement as a means of facilitating health care system integration

BACKGROUND

In recent years many health care providers, physicians, hospitals, and managed care organizations have undergone significant reorganization in both delivery and financing systems. This has created new organizations called integrated or organized delivery systems. Sentara Health System (Norfolk, Va), one of these new integrated entities, developed a unified strategy for clinical process improvement for the entire organization. This system-wide approach had unanticipated problems and benefits.

METHODS

The Sentara Health System created a team responsible for coordinating clinical process improvement activities across its hospitals and ambulatory physician sites. A steering committee directed this team to improve the organization and delivery of care for specific high-cost, high-volume, or problem-prone disease for physicians to manage. A standardized approach aimed at coordinating care across sites was the cornerstone of these activities.

RESULTS

Significant improvements in patient outcomes and a concomitant decrease in costs of care were accomplished for multiple diseases and procedures. These projects uncovered unanticipated barriers to implementing improvement projects in a complex health care system which make implementing these activities far more difficult than for an individual hospital with its medical staff.

CONCLUSION

Coordinating clinical improvement activities across multiple hospitals and other sites of care in a complex integrated delivery system serves important purposes in addition to improving patient care. These projects were an important cultural change agent to transform the individual components of the system into one that is capable of delivering care continuously across multiple sites. Standardization of care practices, policies, and procedures is considerably enhanced by coordinating these activities across the entire system.

Management of hypoplastic aortic arch associated with neonatal coarctation

Controversy still exists as to whether hypoplastic aortic arch frequently associated with neonatal coarctation, should be enlarged at the time of coarctation repair. To determine the indications for and the outcome of repair of hypoplastic aortic arch, pre- and postoperative angiograms/echocardigraphy of 77 cases with isolated (n = 25, Group 1) or complex (n = 52, Group 2) neonatal coarctation operated upon between 1/80 and 12/89 were reviewed. Age was 5-14 days (mean 8 +/- 1.6). Aortic arch/ascending aorta diameter ratio (AR/AA) as a measure of the degree of aortic arch hypoplasia was 0.39-0.64 (0.52 +/- 0.04) in isolated and 0.15-0.47 (0.34 +/- 0.06) in complex coarctation (p < 0.05). Left subclavian flap aortoplasty was used in 72 patients; alone in 25, in combination with pulmonary artery banding in 43 patients, and simultaneously with intracardiac repair in 4 patients. Extensive reconstruction of aortic arch and coarctation with synthetic patch was performed in the remaining 5 patients (AR/AO = 0.16 +/- 0.03) using cardiopulmonary by-pass at the time of intracardiac repair. Operative mortality was 2/76 (2.5%). Follow-up is 6.6 +/- 1.4 years. Recoarctation occurred in 3 patients (4%). AR/AA increased to 0.86 +/- 0.1 in isolated (p < 0.05 vs preoperative) and to 0.7 +/- 0.1 in complex coarctation (p < 0.05 vs preoperative). In the majority of cases, hypoplastic aortic arch associated with coarctation grows satisfactorily following simple repair of coarctation with no significant residual narrowing.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of hypoalbuminemia and parenteral nutrition on free water excretion and electrolyte-free water resorption

OBJECTIVE

To measure the effect of human albumin supplementation during parenteral nutrition on serum albumin concentrations, colloid oncotic pressure, free water clearance, electrolyte-free water resorption, and sodium excretion.

DESIGN

Prospective, randomized, controlled trial.

SETTING

Tertiary care center.

PATIENTS

Thirty adult, hypoalbuminemic patients who required parenteral nutrition.

INTERVENTIONS

Parenteral nutrition (control) or parenteral nutrition plus human albumin 25 g/L as a continuous infusion (treatment) for a 5-day study period.

MEASUREMENTS

On days 1 and 5, serum albumin concentration, colloid oncotic pressure, free water clearance, electrolyte-free water resorption, and sodium excretion were measured.

RESULTS

Serum albumin concentrations increased significantly from day 1 to day 5 in both groups (control: 2.0 +/- 0.1 [mean +/- SEM] vs. 2.3 +/- 0.1 g/dL [20 +/- 1 vs. 23 +/- 1 g/L], p = .02; treatment: 2.2 +/- 0.1 vs. 3.5 +/- 0.2 g/dL [22 +/- 1 vs. 35 +/- 2 g/L], p = .0001). Day 5 serum albumin concentrations were significantly higher in the treatment group compared with control (p = .0001). Colloid oncotic pressure increased significantly from day 1 to day 5 in the treatment group (17.8 +/- 0.8 vs. 25.1 +/- 1.0 mm Hg, p = .0001), and was significantly higher than control at day 5 (p = .0001). No significant differences were found for free water clearance, electrolyte-free water resorption, or sodium excretion within or between groups.

CONCLUSIONS

In hypoalbuminemic patients, human albumin supplementation during parenteral nutrition results in significant increases in serum albumin concentrations and colloid oncotic pressure, but has no apparent effect on free water clearance, electrolyte-free water resorption, or sodium excretion.

Randomized comparative study of cefixime versus cephalexin in acute bacterial exacerbations of chronic bronchitis

Patients with purulent exacerbation of chronic bronchitis were randomized to receive either a single 400-mg daily dose of cefixime or 250 mg of cephalexin, orally, four times a day. Patients were males with a mean age of 63 years. Of the 86 patients, 71 (82%) had bronchitis caused by a single organism (29 by Haemophilus influenzae, 27 by Branhamella catarrhalis, 9 by gram-negative enteric organisms, 6 by Streptococcus pneumoniae), while more than one pathogen was implicated in 15 patients (18%). A total of 70.8% of the cefixime group and 50% of the cephalexin group were clinically cured (chi 2 = 3.89, P less than 0.05); however, when the categories of cured and improved were combined, no significant difference was noted between treatment groups (chi 2 = 3.39, P = 0.06). Analysis of side effects included all 130 evaluable and nonevaluable patients: diarrhea was noted in six patients in the cefixime group and none of the patients in the cephalexin group (P = 0.013 by the Fisher exact test). The diarrhea was mild and self-limited in all cases. B. catarrhalis has emerged as a major cause of exacerbation of bronchitis in our experience; there is an increased need to emphasize the examination of sputum samples by Gram staining if cost-effective antibiotic choices are to be made; any empirically chosen antibiotic should have activity against beta-lactamase-producing strains of B. catarrhalis as well as S. pneumoniae and H. influenzae.

MR imaging of double outlet right ventricle

Five patients with angiographically proven diagnosis of double outlet right ventricle (DORV) were studied with magnetic resonance (MR) imaging. Magnetic resonance was compared with angiography and echocardiography. Contiguous electrocardiographic-gated spin-echo images were acquired on a 0.35 T imager. Magnetic resonance was equivalent to echocardiography in demonstrating relative relationships of the great arteries with respect to each other, the relative positions of the great arteries with respect to the ventricular septal defect (VSD), and the caliber of the great vessels. It was comparable in visualization of the size and position of the VSD and position of the atrioventricular valves. Due to limited spatial resolution, MR failed to identify chordal straddle of a tricuspid valve and incorrectly interpreted pulmonary stenosis as pulmonary atresia. A small patch leak of an internal baffle was only visualized on angiography. We conclude that MR is superior to echocardiography in the noninvasive assessment of the spatial arrangement and caliber of the great vessels. As such, it is a useful adjunct to echocardiography in the noninvasive assessment of DORV.