Location coding by the human visual system: multiple topological adaptations in a case of strabismic amblyopia

Amblyopia, a major cause of vision loss, is a developmental disorder of visual perception commonly associated with strabismus (squint). Although defined by a reduction in visual acuity, severe distortions of perceived visual location are common in strabismic amblyopia. These distortions can help us understand the cortical coding of visual location and its development in normal vision, as well as in amblyopia. The history of retinotopic mapping in the visual cortex highlights the potential impact of amblyopia. Theories of amblyopia include topological disarray of receptors in primary visual cortex, undersampling from the amblyopic eye compared with normal eyes, and the presence of anomalous retinal correspondence or multiple cortical representations of the strabismic fovea. We examined the distortions in a strabismic amblyope, using a pop-out localization task, in which normal observers made errors dependent on the visual context of the stimulus. The localization errors of the strabismic amblyope were abnormal. We found that none of the available theories could fully explain this one patient's localization performance. Instead, the observed behavior suggests that multiple adaptations of the underlying cortical topology are possible simultaneously in different parts of the visual field.     

Implicit learning of predictive relationships in three-element visual sequences by young and old adults

Knowledge of sequential relationships enables future events to be anticipated and processed efficiently. Research with the serial reaction time task (SRTT) has shown that sequence learning often occurs implicitly without effort or awareness. Here, the authors report 4 experiments that use a triplet-learning task (TLT) to investigate sequence learning in young and older adults. In the TLT, people respond only to the last target event in a series of discrete, 3-event sequences or triplets. Target predictability is manipulated by varying the triplet frequency (joint probability) and/or the statistical relationships (conditional probabilities) among events within the triplets. Results reveal that both groups learned, though older adults showed less learning of both joint and conditional probabilities. Young people used the statistical information in both cues, but older adults relied primarily on information in the 2nd cue alone. The authors conclude that the TLT complements and extends the SRTT and other tasks by offering flexibility in the kinds of sequential statistical regularities that may be studied as well as by controlling event timing and eliminating motor response sequencing.     

Interdisciplinary agreement in the diagnosis of headache types

The degree of agreement in independent diagnosis of headache by a neurologist and a clinical psychologist was determined to be 86.4% in a series of 66 consecutive patients. Fifty-five percent of the disagreements were due to the patients' giving different information to the two assessors. This source of disagreement was associated with the patients' having had previous psychiatric treatment.This research was supported in part by Grant NS-15235 from the National Institute of Neurological and Communicative Disorders and Stroke.     

Intrahemispheric differentiation of vowels: Principal component analysis of auditory evoked responses to computer-synthesized vowel sounds

Auditory evoked brain responses (AER) were recorded in response to a series of synthesized vowel sounds which varied in formant bandwidth. Multivariate analyses indicated that changes in AER component structure recorded from different scalp regions over both hemispheres varied as a function of different vowel sounds and formant bandwidth. No interhemispheric differences in scalp AER distributions were noted.     

Emotional well-being of college students in health courses with and without an exercise component

This study was designed to examine the effects of exercise on indices of emotional well-being of 584 college students enrolled in either a lecture-only health course or one of six health-fitness courses, each using a different mode of exercise including cross-training, aerobics, yoga, circuit weight training, swimming, and walk/jog. Each participant completed the Self-perception Profile for College Students developed by Neeman and Harter. Analysis yielded significant differences on five indices of emotional well-being (Global Self-worth, Appearance, Romantic Relationships, Social Acceptance, and Athletic Competence) between pre- and posttest scores of participants enrolled in the health-fitness courses, while no differences were found between pre-and posttest scores of participants enrolled in the lecture-only health course. Of the seven subscales examined, a significant interaction effect was found between sex/time and Romantic Relationships/Athletic Competence, with women reporting greater gains than men.     

Bound context features are integrated at encoding

In the present research, we tested the predictions of different accounts of context binding in "remember" judgements. Context binding, defined as the stochastically dependent retrieval of two different context features, has previously been suggested to be due to mechanisms operating at retrieval either by cueing among context features (Meiser & Br?der, 2002) or by cueing between item and context features (Starns & Hicks, 2008). These accounts, however, do not make specific assumptions regarding the underlying memory representation supporting context binding. By contrast, here we propose that a binding process at encoding integrates item and context information into a coherent memory representation. Varying the presentation of the context features during encoding either with both context features presented simultaneously or with features spread over two encoding episodes, data from two experiments corroborate the notion that binding is produced at encoding. This result suggests that a binding process integrating the context features at encoding is necessary for stochastically dependent retrieval of context features.     

An assessment of body appreciation and its relationship to sexual function in women

Objectification theory posits internalization of an observer's gaze may negatively impact women's feelings about their bodies, which may subsequently affect their sexual function. Subjective body image and body size (i.e., body mass index [BMI]) have mixed relationships to women's sexuality, but assessment of positive body image as a sign of resistance to objectification has not been researched. This study explored relations between body appreciation and sexual function in women and assessed whether body size impacted this relationship. Cross-sectional data were collected online from 247 women, ages 18 to 58. Body appreciation scores were modestly negatively correlated with BMI, while BMI was not related to sexual function scores. After controlling for sexual orientation, partner status, and age, body appreciation predicted the arousal, orgasm, and satisfaction aspects of sexual function. Practitioners’ encouragement of body appreciation may improve sexual function in a way that encouraging a reduction in body size may not.     

The Beliefs About Medication Scale: Development, Reliability, and Validity

The purpose of the study was to develop and evaluate a psychometrically sound health belief measure, the Beliefs About Medication Scale (BAMS) that can be used with adolescent chronic illness populations whose prescribed treatment includes oral medication. One hundred and thirty-three adolescents (age 11–18 years) with asthma (n = 60), HIV (n = 31), or inflammatory bowel disease (n = 42) completed the BAMS and, along with their parent, a self-report medication interview. A confirmatory factor analysis supported the hypothesized subscales of Perceived Threat, Positive Outcome Expectancy, Negative Outcome Expectancy, and Intent to Adhere to treatment. The subscales evidenced good internal consistency and 3-week test-retest reliability. Univariate and multivariate analyses demonstrated that the health belief constructs accounted for 22% of the variance in medication adherence beyond demographic and illness characteristics. The study provides preliminary evidence of the reliability and validity of a theoretically based measure of health beliefs for adolescents. The BAMS may be a useful tool to evaluate the psychological barriers to adherence that place teenagers at risk for nonadherence.     

Speeded detection of vowels: A cross-linguistic study

In four experiments, listeners’ response times to detect vowel targets in spoken input were measured. The first three experiments were conducted in English. In two, one using real words and the other, nonwords, detection accuracy was low, targets in initial syllables were detected more slowly than targets in final syllables, and both response time and missed-response rate were inversely correlated with vowel duration. In a third experiment, the speech context for some subjects included all English vowels, while for others, only five relatively distinct vowels occurred. This manipulation had essentially no effect, and the same response pattern was again observed. A fourth experiment, conducted in Spanish, replicated the results in the first three experiments, except that miss rate was here unrelated to vowel duration. We propose that listeners’ responses to vowel targets in naturally spoken input are effectively cautious, reflecting realistic appreciation of vowel variability in natural context.