The values you endorse set the body you see: The protective effect of intrinsic life goals on men's body dissatisfaction

The mass media portrayal of a muscular body type ideal has been increasingly tied to men's body image dissatisfaction. We examined the role of self-determination theory's intrinsic life goals within this body image ideal and its potential as a moderator of this dissatisfaction. We first tested the moderating effect of intrinsic life goals on the link between magazine consumption and body image dissatisfaction via an online questionnaire (Study 1; N = 826), then experimentally manipulated these goals and exposure to images of muscular male models (Study 2; N = 150). A robust protective effect of intrinsic goals on body image satisfaction was observed - the relationship between magazine consumption and body image dissatisfaction was only significant among individuals with a lower level of intrinsic life goal orientation. When participants' intrinsic goals were momentarily heightened, they reported significantly less body image dissatisfaction, compared to those not receiving a strengthening of these goals. The results are the first to find a protective effect of intrinsic life goals on men's body image, and have important implications for intervention.

Chinese version of the Schizotypal Personality Questionnaire: Factor structure replication and invariance across sex

INTRODUCTION

The Schizotypal Personality Questionnaire (SPQ) is a self-report measure assessing symptoms of schizotypy. The SPQ has been used in both normative and clinical samples and has much theoretical and empirical support. A three-factor structure of the SPQ, derived on the basis of work in schizophrenia, consisting of Cognitive-Perceptual, Interpersonal, and Disorganized factors, has been well replicated. The present study aimed to (i) validate this three-factor structure in the Chinese version of the SPQ in a sample of individuals of Chinese ethnicity, and (ii) test for invariance across sex.

METHODS

A total of 209 (99 males) undergraduate university students (Mage  = 19.5, SD = 1.6) were administered the SPQ.

RESULTS

Confirmatory factor analysis indicated a better fit between the data and the three-factor model compared with a one-factor model. Multigroup confirmatory factor analysis also found strong measurement invariance across sex.

DISCUSSION

The current results add to a growing body of literature evidencing cross-cultural validity of the SPQ and its invariance across sex. Research and clinical implications of the current results are discussed.

Knowledge, attitudes, and perceptions of autism spectrum disorder in a stratified sampling of preschool teachers in China

BACKGROUND

In China, children with Autism Spectrum Disorder (ASD) can potentially benefit from universal education policies and recent initiatives designed to address the needs of children with developmental disorders. However, adequate schooling is often unavailable for children with ASD, in part because teachers lack the knowledge and skills needed to work with this population. To better understand the current state of knowledge of ASD in China, we surveyed knowledge and attitudes regarding the disorder in preschool teachers.

METHODS

A total of 471 preschool teachers in the cities of Guangzhou and Foshan, China completed questionnaires assessing participant demographics, knowledge of typical child development and knowledge of ASD, attitudes towards ASD, practices and self-perceptions of efficacy in the education of children with ASD, and awareness of organizations and intervention approaches devoted to the care of individuals with ASD. The correlation between individual- and school-level variables with current knowledge of typical child development and ASD was examined using univariate and multivariate analyses.

RESULTS

The majority (84%) of participants answered correctly more than half of the questionnaire items assessing understanding of typical child development. In contrast, 83% provided inaccurate responses to more than half of the questionnaire items assessing knowledge of ASD. Knowledge of typical child development and knowledge of ASD were both associated with geographic region (teachers in Guangzhou had greater knowledge than those in Foshan, p < 0.0001). Knowledge of ASD was also associated with a higher education level (p < 0.05) and school type (p = 0.023). In general, participants believed fairly strongly in the need for greater service provision for children with ASD, and were receptive towards receiving additional specialized training. Most participants were unaware of ASD-specific organizations and empirically validated intervention approaches.

CONCLUSIONS

Knowledge of ASD is lacking in preschool teachers in China, and greater teacher training and instruction is needed. Nonetheless, teachers report a willingness and motivation to gain the skills needed to maximize the educational experiences of children with ASD.

Autism spectrum disorder etiology: Lay beliefs and the role of cultural values and social axioms

Recent research examining the explanations given by the public (i.e. lay beliefs) for autism spectrum disorder often reveals a reasonably accurate understanding of the biogenetic basis of the disorder. However, lay beliefs often manifest aspects of culture, and much of this work has been conducted in western cultures. In this study, 215 undergraduate university students in Macau, a Special Administrative Region of China, completed self-report measures assessing two beliefs concerning autism spectrum disorder etiology: (1) a belief in parental factors and (2) a belief in genetic factors. Potential correlates of lay beliefs were sought in culture-specific values, and more universal social axioms. Participants were significantly more likely to endorse parenting, relative to genetic factors, as etiological. A perceived parental etiology was predicted by values of mind-body holism. Beliefs in a parental etiology were not predicted by values assessing collectivism, conformity to norms, a belief in a family's ability to obtain recognition through a child's achievement, or interpersonal harmony, nor by the social axioms measured (e.g. social cynicism, reward for application, social complexity, fate control, and religiosity). Beliefs in a genetic etiology were not predicted by either culture-specific values or social axioms. Implications of the current results are discussed.

Autistic spectrum disorder, epilepsy, and vagus nerve stimulation

PURPOSE

In individuals with a comorbid autistic spectrum disorder and medically refractory epilepsy, vagus nerve stimulation may offer the potential of seizure control and a positive behavioral side effect profile. We aimed to examine the behavioral side effect profile using longitudinal and quantitative data and review the potential mechanisms behind behavioral changes.

METHODS

We present a case report of a 10-year-old boy with autistic spectrum disorder and epilepsy, who underwent vagus nerve stimulation subsequent to unsuccessful treatment with antiepileptic medication.

RESULTS

Following vagus nerve stimulation implantation, initial, if temporary, improvement was observed in seizure control. Modest improvements were also observed in behavior and development, improvements which were observed independent of seizure control.

CONCLUSIONS

Vagus nerve stimulation in autistic spectrum disorder is associated with modest behavioral improvement, with unidentified etiology, although several candidates for this improvement are evident.

Traditional Chinese medicinal herbal tea consumption, self-reported somatization, and alexithymia

INTRODUCTION

Somatic presentations of distress are common cross-culturally, although perhaps more so in Asian cultures. Somatic presentations of distress may be associated with alexithymia, a difficulty in experiencing and expressing emotions. Although the constructs of somatization and alexithymia have been examined in depth both within and across cultures, there is minimal information on culture-specific behaviors utilized to cope with stress in individuals who tend to somaticize distress or are alexithymic. The current report investigates the association between somatization and alexithymia, and a culture-specific behavior of traditional Chinese medicinal herbal tea consumption, in a nonclinical, young adult sample.

METHODS

A sample of 222 undergraduate university students of Chinese ethnicity completed self-report measures of somatization and the related construct of somatosensory amplification, alexithymia, and attitude toward the consumption of herbal tea possessing traditional Chinese medicinal value.

RESULTS

After controlling for gender, alexithymia was significantly correlated with somatization (r[220] = 0.29, P < 0.05) and somatosensory amplification (r[220] = 0.19, P < 0.05). Attitudes toward herbal tea consumption were significantly correlated with somatosensory amplification (r[220] = 0.16, P < 0.05).

DISCUSSION

The connection between alexithymia and somatization was confirmed in the current report in a nonclinical sample. A culture-specific behavior (consumption of traditional Chinese medicinal herbal tea) was significantly associated with somatosensory amplification. Potential etiologies and implications of the current findings are discussed.

Somatic presentations of distress in China

OBJECTIVE

Somatic presentations of distress are common cross-culturally and are thought to predominate in Asian cultures such as that of China. From an etic perspective, researchers utilizing empirically validated standardized assessment measures find that somatic symptoms are no more common in individuals of Chinese descent than they are in individuals of European descent. In contrast, patient presentations are heavily influenced by culture and are associated with patterns of illness behavior. The objective of the current review is to determine the culture-specific factors contributing to somatic presentations and descriptions of distress in China.

METHOD

The current review was based on a literature search of PubMed and PsychInfo using the terms 'China,' 'Asia,' 'somatoform,' 'somatization,' and 'psychogenic.'

RESULTS

Factors contributing to somatic presentations of distress in China include stigma and help-seeking behavior, and assessment approaches that ignore culture-specific patterns of symptom reporting, fail to incorporate somatic metaphor and Chinese conceptualizations of distress that emphasize bodily sensation, and ignore the role that culture-specific normative data and culture specific response patterns may produce on assessment results.

CONCLUSIONS

From an emic perspective, there are numerous factors contributing to the appearance of a predominantly somatic presentation of distress in China. Implications for clinical practice are discussed.

Prevalence of autism spectrum disorders and influence of country of measurement and ethnicity

BACKGROUND

The prevalence of autism spectrum disorders (ASD) is generally somewhat lower in countries outside of North America and Europe. While there are culture-specific patterns of social cognitive processing, the influence of such patterns upon ASD prevalence has yet to be fully explored.

METHODS

A comprehensive literature search for original articles reporting ASD prevalence was undertaken. Data across studies were compared with a particular focus on variables of geographic residence and ethnicity.

RESULTS

ASD prevalence varies across countries in a manner that appears to suggest that the greatest influence is due to methodological variables. The nature of a potential influence of culture-specific patterns of cognitive processing upon prevalence remains unknown. The available little data concerning the association between ethnicity and prevalence are limited to studies within the United States (US) showing differences in children of Hispanic descent relative to Whites, a finding for which a definitive explanation is lacking.

CONCLUSIONS

Available evidence suggests that methodological factors are largely responsible for differences in ASD prevalence across studies. The much discussed increase in prevalence in ASD has been observed worldwide, suggesting that the refinement of diagnostic methodology and/or broadening diagnostic concept is not limited to Western countries. Within individual countries, only in the US has the influence of ethnicity upon ASD prevalence been examined in depth. In the US, children of Hispanic descent have the lowest prevalence of ASD, while Whites tend to have the highest prevalence of ASD. Hypothesized etiological factors for such prevalence differences include methodological factors, socioeconomic variables, and bias.

Comparing the convergent validity and clinical utility of the Behavior Assessment System for Children-Parent Rating Scales and Child Behavior Checklist in children with epilepsy

The convergent validity and clinical utility of two parent-report child behavior rating scales, the Behavior Assessment System for Children-Parent Rating Scales (BASC-PRS) and Child Behavior Checklist/Ages 6-18 (CBCL), in children with epilepsy were examined. Analogous broadband and narrowband behavior rating scales were evaluated in 60 subjects aged 6-17 years (mean=11.0, SD=3.4) with Full Scale IQ >70. Correlations for each similarly labeled scale were statistically significant (P<0.002) and greater with broadband (r=0.71-0.79) than with narrowband (r=0.41-0.78) scales. The BASC captured significantly less composite internalizing symptoms (P<0.002), but more unusual thought processes (P<0.0002) and attention problems versus a CBCL DSM-oriented attention-deficit/hyperactivity disorder scale (P<0.002). Variation in the correlations between measures may stem from underlying differences between rationally-and empirically-derived approaches to test construction. Both the CBCL and BASC have diagnostic and clinical utility in assessing behavior problems in pediatric epilepsy.

Neuropsychologic performance of children with epilepsy on the NEPSY

Neuropsychologic test scores from a group of children with epilepsy were compared to the standardization sample of the NEPSY: A Developmental Neuropsychological Assessment, a relatively new neuropsychologic testing instrument. Nineteen children with a confirmed diagnosis of epilepsy (11 boys, 8 girls), aged 3-12 years, participated. Attention/executive function, language, sensorimotor, visuospatial, and learning/memory domain scores were examined, as well as individual subtest scores. The mean scores on the attention/executive function, language, and sensorimotor domains were >1.5 standard deviations below the normative mean, and significantly lower than the mean visuospatial domain score (P < 0.05). The mean language domain score was also significantly lower than the learning/memory score (P < 0.05). Mean subdomain scores varied, with impairment on two tasks measuring rapid automatic processing and graphomotor precision, respectively. On the majority of subtests, 15% or more of the sample scored in the impaired range. Associations between patient age, seizure onset age, seizure frequency, and antiepileptic medication status were not associated with outcome, perhaps due in part to the small sample size. The strengths and weaknesses of the NEPSY as a measure of neuropsychologic functioning in children with epilepsy, and its utility in highlighting risks to academic achievement are discussed.

Surgical Outcome in Tuberous Sclerosis Complex: A Multicenter Survey

Multicenter, retrospective analysis of 70 subjects with TSC following surgery for relief of epilepsy revealed significant associations between younger age at seizure onset, present/prior history of infantile spasms, interictal focality (bilateral versus unilateral), and absence of residual postoperative predominant tuber, and poorer postoperative outcome (p < 0.01). Ictal multifocality, mental retardation, and discordant EEG and MRI data showed a negative trend toward outcome, but were not significant.

Pediatric Language Mapping: Sensitivity of Neurostimulation and Wada Testing in Epilepsy Surgery

PURPOSE

Functional mapping of eloquent cortex with electrical neurostimulation is used both intra- and extraoperatively to tailor resections. In pediatric patients, however, functional mapping studies frequently fail to localize language. Wada testing has also been reported to be less sensitive in children.

METHODS

Thirty children (4.7 - 14.9 years) and 18 adult controls (18-59 years) who underwent extraoperative language mapping via implanted subdural electrodes at the NYU Comprehensive Epilepsy Center were included in the study. Ten children and 14 adults underwent preoperative Wada testing. Success of the procedures was defined as the identification of at least one language site by neurostimulation mapping and determination of hemispheric language dominance on the Wada test.

RESULTS

In children younger than 10.2 years, cortical stimulation identified language cortex at a lower rate than was seen in children older than 10.2 years and in adults (p<0.05). This threshold, demonstrated by survival and chi2 analysis, was sharply defined in our data set. Additionally, Wada testing was more likely to be successful than was extraoperative mapping in this younger age group (p<0.05).

CONCLUSIONS

Analysis of our series demonstrates that language cortex is less likely to be identified in children younger than 10 years, suggesting that alternatives to the current methods of cortical electrical stimulation, particularly the use of preoperative language lateralization, may be required in this age group.

The Factor Structure of the CVLT-C in Pediatric Epilepsy

The current study used archival data to evaluate the fit of six latent variable models, originally generated by Donders (1999), for the California Verbal Learning Test-Children's Version (CVLT-C; Delis, Kramer, Kaplan, & Ober, 1994) in a large (N = 289) sample of pediatric epilepsy cases presenting at three tertiary treatment centers. Using confirmatory factor analysis, we found that a model including factors of Attention Span, Learning Efficiency, Free Delayed Recall, Cued Delayed Recall, and Inaccurate Recall demonstrated the best relative fit for our data. These findings are consistent with those reported by Donders (1999) in his reanalysis of the CVLT-C standardization sample data, supporting the validity of this factorial model in pediatric epilepsy populations.

Mental retardation and relation to seizure and tuber burden in tuberous sclerosis complex

In patients with tuberous sclerosis complex (TSC), the high rates of mental retardation are associated with cortical tubers, seizure activity, and genetic factors. The goal of the study was to investigate the relationship between bilateral cortical tubers and seizure variables and mental retardation in individuals with TSC. The records of 27 patients with TSC (age 6 months to 33 years) undergoing neuropsychological assessment and the following clinical variables were examined: bilateral versus non-bilateral cortical tubers, the age of seizure onset, and presence of infantile spasms. Results were statistically analyzed. Bilateral cortical tubers (p=0.02) and early age of seizure onset (p=0.04) were significantly related to impaired cognitive functioning. Only one of the seven patients with normal cognitive functioning had bilateral tubers, whereas 13/21 patients with intellectual impairment had bilateral tubers. Patients with normal cognitive functioning experienced a mean age of seizure onset after 6 years. A trend was observed between infantile spasms and cognitive functioning (p=0.06); the lack of statistical significance likely reflects the small sample size. Neither age nor gender was related to cognitive status. Further investigation incorporating additional neuroimaging factors, antiepileptic treatment effects, and genetic variables, is needed.

Epilepsy surgery in young children with tuberous sclerosis: results of a novel approach

OBJECTIVE

Tuberous sclerosis complex (TSC) is associated with medically refractory epilepsy and developmental delay in children and usually results from cortical tubers. Seizures that begin in young patients are often refractory and may contribute to development delay. Functional outcome is improved when seizures are controlled at an early age. Previous reports have shown modest benefit from surgical resection of single tubers/seizure foci in older children; however, many children with TSC develop uncontrolled seizures before age 1. To identify patients who might benefit from surgery and to maximize outcome, we used a novel surgical approach in young children that consists of invasive intracranial monitoring, which is typically 3-staged and often bilateral.

METHODS

Of 110 consecutive children who underwent epilepsy surgery by a single surgeon in the past 6 years, 25 patients (9 boys and 16 girls) had TSC. At the time of their first surgery at our institution, they were a median age of 4.0 years. A total of 31 separate admissions for epilepsy surgery in these 25 patients were identified. Bilateral electrode placement was performed in 13 children whose seizures could not be lateralized definitively preoperatively, and 22 patients underwent 3-stage surgeries.

RESULTS

At 6 months or longer after the initial resection, 21 (84%) children were class I, 2 (8%) children were class II, and 2 (8%) children were class IV. At a mean follow-up of 28 months, 17 (68%) children were class I, 6 (24%) were class II, and 2 (8%) were class III. Four of the 5 children who initially were rejected as surgical candidates because of multifocality and who required initial bilateral electrode study are now seizure-free.

CONCLUSIONS

This approach can help to identify both primary and secondary epileptogenic zones in young TSC patients with multiple tubers. Multiple or bilateral seizure foci are not necessarily a contraindication to surgery. Long-term follow-up will determine whether this approach has durable effects.

Developmental outcome of epilepsy surgery in tuberous sclerosis complex

In Tuberous sclerosis complex (TSC), neurological dysfunction, usually in association with epilepsy, is responsible for the greatest degree of disease-related disability. Epilepsy surgery is increasingly recognized as a therapeutic option given the often medication-resistant nature of the disease. Seven subjects with medically refractory epilepsy associated with TSC, who underwent surgery at a tertiary care epilepsy center and in whom both preoperative and postoperative neuropsychological data were available, were examined. The Vineland Adaptive Behavior Scales, and in one case, the WISC-III were utilized. Postoperatively, the composite standard scores declined in six of the seven subjects, although for the most part this decline was quite modest (8 points or less in 5/6 subjects). The mean overall developmental/intellectual quotients were comparable across assessments (preoperative M = 55, SD = 20.3; postoperative M = 49 SD = 16.6). Good outcomes appeared to be related to seizure relief. Age estimates of developmental level indicated developmental progress in the majority of subjects in the current sample, and may yield greater clinical information for individuals with developmental delay than do standard scores.

Neurocutaneous syndromes: behavioral features

Neurocutaneous syndromes are disorders characterized by a neurological abnormality and cutaneous manifestations. Three of the more common neurocutaneous syndromes are Sturge-Weber syndrome, tuberous sclerosis, and neurofibromatosis. This review focuses on the cognitive and behavioral features of these syndromes.

Late-onset Tay-Sachs disease: phenotypic characterization and genotypic correlations in 21 affected patients

PURPOSE

The purpose of this study was to describe the phenotype (and corresponding genotype) of adult patients with late-onset Tay-Sachs disease, a clinical variant of the GM2-gangliosidoses.

METHODS

A comprehensive physical examination, including neurological assessments, was performed to establish the current disease pattern and severity. In addition, the patients' past medical histories were reviewed. The patients' alpha-subunit mutations (beta-Hexosaminidase A genotype) were determined and correlated with their corresponding clinical findings and disease course.

RESULTS

Twenty-one patients (current mean age: 27.0 years; range: 14-47 years) were identified. The pedigree revealed a relative with the "classic" infantile or late-onset form of Tay-Sachs disease in four (out of 18) unrelated families. The patients were predominantly male (15/21 individuals) and of Ashkenazi Jewish ancestry (15/18 families). Mean age at onset was 18.1 years; balance problems and difficulty climbing stairs were the most frequent presenting complaints. In several cases, the diagnosis was delayed (mean age at diagnosis: 27.0 years). Analysis of the beta-hex A gene revealed the G269S mutation as the most common disease allele; found in homozygosity (N = 1) or heterozygosity (N = 18; including 2 sib pairs). Disease onset (age 36 years) was delayed and progression relatively slower in the homozygous G269S patient. Two siblings (ages 28 and 31 years), of non-Jewish ancestry, were compound heterozygotes (TATC1278/W474C); their clinical course is dominated by psychiatric problems. Brain imaging studies revealed marked cerebellar atrophy in all patients (N = 18) tested, regardless of disease stage.

CONCLUSIONS

Late-onset Tay-Sachs disease is an infrequent disorder and the diagnosis is often missed or delayed (by approximately 8 years). Early on, the majority of patients develop signs of either cerebellar or anterior motor neuron involvement. Affected individuals may also develop psychotic episodes. In most cases, the later-onset of expression results from the presence of at least one allele (usually the G269S mutation), associated with residual enzyme (beta-hexosaminidase A) activity. A positive family history is a valuable clue, enabling early diagnosis. Nonspecific cerebellar atrophy on brain imaging is another important finding. This entity should be considered among patients presenting with speech, gait, and balance problems, and those with psychiatric disorders even when focal neurologic deficits may be initially absent. Accurate diagnosis will permit appropriate genetic counseling regarding disease prognosis and reproductive risks.

Neuropsychological assessment of patients with late onset GM2 gangliosidosis

OBJECTIVE

To characterize cognitive status in a sample of individuals with late-onset GM2 gangliosidosis (commonly referred to as late-onset Tay-Sachs disease).

METHODS

Seventeen subjects (13 men, 4 women) diagnosed with GM2 gangliosidosis were evaluated. Subjects ranged in age from 18 to 56 years and were in various stages of disease progression. Subjects underwent comprehensive neuropsychological assessment. Impairment was defined as performance more than 1.6 SD below the normative mean.

RESULTS

Group mean performance was within the denoted normal range on all measures except on a task assessing visual sequencing and set shifting. Approximately one-half of the sample scored in the impaired range on measures of processing speed, visual sequencing, and set shifting. One-third of the sample also scored in the impaired range on measures of delayed verbal recall. Impairment tended to be restricted to a subset of the sample, as 5 of the 14 subjects able to undergo formal testing accounted for 70% of the total number of impaired scores. If the three subjects unable to participate in formal testing are also considered impaired, 47% of the current sample exhibited significant cognitive impairment in at least one cognitive domain.

CONCLUSION

In late-onset GM2 gangliosidosis, there is a risk of impairment in executive functioning and memory as well as cerebellar dysfunction. Dementia was not present in any subjects in the current sample.

Cognitive and behavioral correlates of tuberous sclerosis complex

Tuberous sclerosis complex is a multisystem disorder in which neurologic problems cause the greatest disability. High rates of mental retardation and autism spectrum disorders are associated with the diagnosis. Early-onset seizures and increased tuber burden are risk factors for cognitive impairment. Early-onset seizures, particularly infantile spasms, are risk factors for autism. Tubers within the temporal lobe and cerebellum are often mentioned as risk factors for autism, although the findings are inconsistent. Seizure control is important for developmental outcome and quality of life. Early behavioral assessment and therapeutic intervention, as well as seizure control, are the most effective means of promoting neurodevelopmental outcome.

Group psychoeducation as treatment for psychological nonepileptic seizures

There is no consensus for the type(s) of treatment(s) that may be effective or ineffective for psychological nonepileptic seizures (PNES). We provided an open-ended group psychotherapy program to 10 patients with PNES, including a disorder-specific psychoeducation treatment component in the first 10 weeks. Seizure frequency and questionnaire responses were examined pre- and posttreatment in all 7 of 10 individuals who completed the majority of the psychoeducational sessions. Four individuals experienced no change in seizure frequency; in three of these this was due to a cessation of events at treatment initiation. Two individuals experienced a decline; and one, an increase, in seizure frequency. Significant decreases were reported in posttraumatic (P=0.003) and dissociative (P=0.04) symptoms and emotionally based coping mechanisms (P=0.03). There was also a trend toward improved quality of life (P=0.07). Experience/expression of anger remained stable. Psychoeducation may be an effective method of treating PNES and may improve coping strategies and reduce PNES-associated psychopathology in some patients. Additional controlled studies on larger samples are needed.

Variation in stereoacuity: normative description, fixation disparity, and the roles of aging and gender

PURPOSE

Variation in stereoacuity was examined in a large group of observers with Snellen acuity of 20/30 or less.

METHODS

Threshold retinal disparity for 2.78 degrees x 2.28 degrees rectangular test stimuli was determined as a function of the retinal disparity (varied from 55 arcmin uncrossed to 55 arcmin crossed) of a 5.57 degrees x 4.8 degrees rectangular pedestal stimulus in 160 observers 15 to 79 years of age. In most cases, data were collected during viewing of random dot stereograms (RDSs) presented for 100-ms, which prevents involvement of vergence or monocular depth cues.

RESULTS

When plotted logarithmically, 100-ms thresholds in 106 observers less than 60 years of age approximated a normal distribution (mean, 1.57 +/- 0.227 [SD] log arcsec [37 linear arcsec]). Among these, one observer was supernormal, 88% were within the normal range (+/-2 SD of the log mean), 2% had elevated thresholds, and 8% failed testing with 100-ms stimuli but had residual binocular depth discrimination; 1 observer was stereoblind. In contrast, only 37% of the observers aged 60 to 69 and 25% of the observers aged 70 to 79 had stereoacuity within the normal range. Moreover, the extent of the stereo deficiencies became more pronounced with age. Fixation disparity was operationally defined as optimal stereoscopic threshold with a nonzero retinal disparity pedestal. Of the 151 normal observers tested, 89% were maximally sensitive to disparities within 11 arcmin of fixation: all males were maximally sensitive to pedestals within 22 arcmin of fixation, whereas 8% of females had fixation disparities of more than 22 arcmin. Males were more likely to be sensitive with uncrossed-disparity pedestals, whereas females were more likely to be sensitive with crossed disparity.

CONCLUSIONS

Age-related deterioration in stereoacuity is reflected not only by a linear correlation between age and threshold but also by a catastrophic factor that produces more marked deterioration after age 60. Both factors are probably cerebral and not specifically related to stereopsis. The prevalence of fixation disparity in the normal population is probably more common than previously reported.