All is not lost: Post-saccadic contributions to the perceptual omission of intra-saccadic streaks.

Saccades rapidly jerk the eye into new positions, yet we rarely experience the motion streaks imposed on the retinal image. Here we examined spatial and temporal properties of post-saccadic masking-one potential explanation of this perceptual omission. Observers judged the motion direction of a target stimulus, a Gaussian blob, that moved vertically upwards or downwards and then back to its initial position, just as observers made a saccade. We manipulated the onset and offset of the target and of distractors in various spatial relations to the target, and assessed their effect on performance and subjective confidence. Although the presence of the target after the saccade caused the strongest omission, the offset of spatially distant distractor stimuli upon saccade offset also impaired performance. The temporal properties of these two separate effects suggest that, in addition to masking, an independent effect of attentional distraction further accentuates perceptual omission of intra-saccadic motion streaks.

A Bayesian approach to person perception.

Here we propose a Bayesian approach to person perception, outlining the theoretical position and a methodological framework for testing the predictions experimentally. We use the term person perception to refer not only to the perception of others' personal attributes such as age and sex but also to the perception of social signals such as direction of gaze and emotional expression. The Bayesian approach provides a formal description of the way in which our perception combines current sensory evidence with prior expectations about the structure of the environment. Such expectations can lead to unconscious biases in our perception that are particularly evident when sensory evidence is uncertain. We illustrate the ideas with reference to our recent studies on gaze perception which show that people have a bias to perceive the gaze of others as directed towards themselves. We also describe a potential application to the study of the perception of a person's sex, in which a bias towards perceiving males is typically observed.

Eating disorder age of onset in males: distribution and associated characteristics.

The objective of this study was to determine the distribution of age of onset of eating disorders in males as well as the relationship between age of onset and various clinical and demographic characteristics. The medical records of 70 males consecutively admitted to an inpatient eating disorders unit between June of 1992 and June of 2002 were retrospectively reviewed. Age of onset did not significantly differ by admission diagnosis and appeared to have a single peak at about age 14. Inpatients with older ages of onset reported lower percentage of mean matched population weight (r=-0.35, p=0.005) and longer duration of illness (r=0.26, p=0.03) than inpatients with younger ages of onset. This study confirms the findings of previous investigations performed on female samples and also finds some unique aspects of males with eating disorders important to consider in prevention and treatment programs targeting male populations.

A homozygous deletion in the c-erbA beta thyroid hormone receptor gene in a patient with generalized thyroid hormone resistance: isolation and characterization of the mutant receptor.

Different point mutations have been identified in the T3-binding domain of the c-erbA beta thyroid hormone receptor gene that are associated with variant phenotypes of generalized thyroid hormone resistance (GTHR). In most cases of GTHR, heterozygotes are affected; a single mutant allele results in the inhibition of the function of normal thyroid hormone receptors. We report here a novel genetic abnormality, a 3-basepair (bp) deletion in the T3-binding domain of the beta-receptor in a kindred, S, with GTHR. One patient, S1, was the product of a consanguineous union of two heterozygotes and was homozygous for this defect. Heterozygotes from kindred S harbored a CAC deletion at nucleotides 1295-1297, which resulted in the deduced loss of amino acid residue threonine at codon 332, and they displayed elevated free T4 levels and inappropriately normal TSH levels characteristic of other kindreds with GTHR. However, patient S1, who had two mutant alleles, had markedly elevated TSH and free T4 levels and displayed profound abnormalities in brain development and linear growth. A fibroblast c-erbA beta cDNA extending from codon 175 to stop codon 457 was cloned from patient S1, sequenced, and used to create a full-length mutant cDNA. The kindred S mutant receptor was synthesized in vitro and did not bind T3. This mutant receptor did bind with similar avidity as the wild-type human beta-receptor to thyroid hormone response elements of the human TSH beta (-12 to 43 bp) and rat GH (-188 to -160 bp) genes. Kindred S showed the effect in man of heterozygous and homozygous expression of a dominant negative form of c-erbA beta.

A new point mutation in the 3,5,3'-triiodothyronine-binding domain of the c-erbA beta thyroid hormone receptor is tightly linked to generalized thyroid hormone resistance.

Two different mutations in the c-erbA beta thyroid hormone receptor have recently been reported as genetic abnormalities responsible for the syndrome of generalized thyroid hormone resistance (GTHR). We have now found in a third kindred, D, in which GTHR is inherited as a dominant disease, a new point mutation in the T3-binding domain of c-erbA beta. A guanine to cytosine base substitution at nucleotide position 1305, which altered codon-335 from glutamine (CAG) to histidine (CAC), was found in one allele of 10 affected members and was not found in 6 unaffected members. This C-1305 sequence was not present in 106 random alleles, indicating that it was a mutation in c-erbA beta, and it was tightly linked to GTHR in kindred D, with a maximum logarithm of the odds score of 4.19 at a recombination fraction of 0. The tight linkage result confirms that GTHR maps to the c-erbA beta locus in multiple kindreds. In view of the tight linkage between the C-1305 mutation and GTHR, and that this mutation is a nonconservative alteration in a crucial region of the T3-binding domain, it is probably the genetic defect in kindred D responsible for GTHR. The kindred D receptor appears to result in a different phenotype of tissue resistance compared to the previously reported kindred. A receptor with a mutation in the carboxy-terminus of c-erbA beta.

Involuntary treatment of eating disorders.

OBJECTIVE: Involuntary treatment of any psychiatric disorder has always been controversial, especially for eating disorders. Patients with an eating disorder of life-threatening severity frequently refuse hospitalization. In this study, the authors compared individual characteristics and treatment outcomes of patients admitted to an inpatient program for voluntary or involuntary treatment of their eating disorder. METHOD: This study examined 397 patients admitted to an inpatient treatment program over 7 years. Demographic measures, length of illness, weight history, and treatment response of patients admitted for voluntary treatment and those legally committed for involuntary treatment were compared. RESULTS: The two groups were similar in age, gender ratio, and marital status, but those legally committed for involuntary treatment had a longer illness duration and significantly more previous hospitalizations. At admission, the patients legally committed for involuntary treatment were lower in weight and required a significantly longer hospitalization to attain a healthy discharge weight. However, there was no statistically significant difference between involuntary and voluntary patients in rate of weight restoration (2.6 versus 2.2 lb/week, respectively). The groups did not differ in history of comorbid substance abuse or clinical depression but did differ significantly on all admission IQ measures. Eating disorder severity, as assessed by the Eating Attitudes Test-26, Eating Disorder Inventory, and MMPI-II, was similar for both patient groups. CONCLUSIONS: This study suggests that a substantial minority of patients with severe eating disorders will not seek treatment unless legally committed to an inpatient program. Despite the involuntary initiation of treatment, the short-term response of the legally committed patients was just as good as the response of the patients admitted for voluntary treatment. Further, the majority of those involuntarily treated later affirmed the necessity of their treatment and showed goodwill toward the treatment process. Only a long-term follow-up study will indicate whether these two populations differ in the enduring nature of their treatment response.

Thinking with your head and your heart: age differences in everyday problem-solving strategy preferences.

Age and gender differences in perceived effectiveness of problem-focused and emotion-regulatory problem-solving strategies were examined. Using the Q-sort methodology, young, middle-aged, and older participants were asked to rank order, on a continuum from least to most effective, a wide range of possible strategies for dealing with 4 hypothetical, interpersonal problem situations. In addition to global problem-focused and emotion-focused strategies, analyses were conducted on an expanded 10-category system, including 3 problem-focused and 7 emotion-focused categories. In general, participants preferred problem-focused over emotion-focused strategies. However, older adults preferred a combination of problem-focused and emotion-focused strategies, whereas middle-aged and younger age groups preferred problem-focused strategies only, as their top choices. Qualitative age and gender differences were also found in the types of strategies endorsed, particularly for the emotion-focused strategies.

The maternity blues: exploration of a psychological hypothesis.

Previous studies of the maternity blues have failed to identify a consistent factor discriminating between the group of women who experienced the phenomenon and those who did not. The present study hypothesized that the maternity blues are a hormonally-assisted grief reaction which will occur predominantly in women whose antenatal expectation of baby or delivery fails to be fulfilled by the reality events. The hypothesis was tested in a prospective study of 89 women. The phenomenology of the blues was not found to be associated with the hypothesized sense of disappointment or anti-climax despite many womens' experiences falling short of expectation. Rather, the most powerful predictor of the blues was a sense of "pessimism" in late pregnancy which was actually fulfilled by postpartum reality. In addition, the triad comprising of severity of pre-menstrual tension, unplanned pregnancy and consideration given to elective termination in early pregnancy was associated with increased incidence of the blues.

A critical examination of the amenorrhea and weight criteria for diagnosing anorexia nervosa.

BACKGROUND: Amenorrhea and weight loss to below 15% of 'healthy' weight are current diagnostic criteria for anorexia nervosa (AN). This study compares females who meet current International Statistical Classification of Diseases and Related Health Problems, tenth revision (ICD-10) and Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) criteria for AN with females who meet the essential psychopathology and significant self-starvation, but lack either amenorrhea or weight loss below 85%. METHOD: This study retrospectively examined the medical charts of 588 consecutive admissions to an in-patient treatment program. All diagnoses conformed to ICD-10 and DSM-IV. RESULTS: Of 588 admissions, 297 females had some form of AN with 77.4% (230 of 297) meeting current criteria, while 22.6% (67 of 297) with core psychopathology and self-starvation were classified as eating disorders not otherwise specified or 'atypical' because of some menstrual function or final weight above 85%. The groups showed few statistically significant differences on demographics, illness history, and treatment response, psychopathology, or bone density. CONCLUSION: Amenorrhea may not be a useful diagnostic criterion. Also, requiring below 85% of healthy weight may need generalization.

Thyroid hormone and DNA binding properties of a mutant c-erbA beta receptor associated with generalized thyroid hormone resistance.

We have previously reported a family, Kindred A, with autosomal dominant generalized thyroid hormone resistance in which affected members were found to have a mutation in the carboxy-terminal domain of the c-erbA beta thyroid hormone receptor. In the current study, the thyroid hormone and DNA-binding properties of this mutant receptor were determined using c-erbA beta protein synthesized in vitro. Both the wild-type human placental c-erbA beta and Kindred A receptors bound [125I]-triiodothyronine, although the Kindred A receptor had decreased affinity for the hormone. The affinity for triiodothyronine was 4.5 x 10(9) M-1 and 2.3 x 10(10) M-1 for the mutant and wild-type receptors, respectively. No abnormality of DNA-binding was detected with the Kindred A receptor using a sensitive avidin-biotin DNA-binding assay with DNA fragments containing thyroid hormone response elements. The Kindred A mutant receptor which displays abnormal triiodothyronine-binding but normal DNA-binding activities in vitro acts as a dominant negative inhibitor of thyroid hormone action in man.

Production and detection of cold antihydrogen atoms.

A theoretical underpinning of the standard model of fundamental particles and interactions is CPT invariance, which requires that the laws of physics be invariant under the combined discrete operations of charge conjugation, parity and time reversal. Antimatter, the existence of which was predicted by Dirac, can be used to test the CPT theorem-experimental investigations involving comparisons of particles with antiparticles are numerous. Cold atoms and anti-atoms, such as hydrogen and antihydrogen, could form the basis of a new precise test, as CPT invariance implies that they must have the same spectrum. Observations of antihydrogen in small quantities and at high energies have been reported at the European Organization for Nuclear Research (CERN) and at Fermilab, but these experiments were not suited to precision comparison measurements. Here we demonstrate the production of antihydrogen atoms at very low energy by mixing trapped antiprotons and positrons in a cryogenic environment. The neutral anti-atoms have been detected directly when they escape the trap and annihilate, producing a characteristic signature in an imaging particle detector.