Vance Zemon

Growth and Development of Premature Infants Fed Predominantly Human Milk, Predominantly Premature Infant Formula, or a Combination of Human Milk and Premature Formula

Background In a recent meta-analysis, human milk feeding of low birth-weight (LBW) infants was associated with a 5.2 point improvement in IQ tests. However, in the studies in this meta-analysis, feeding regimens were used (unfortified human milk, term formula) that no longer represent recommended practice. Objective To compare the growth, in-hospital feeding tolerance, morbidity, and development (cognitive, motor, visual, and language) of LBW infants fed different amounts of human milk until term chronologic age (CA) with those of LBW infants fed nutrient-enriched formulas from first enteral feeding. Methods The data in this study were collected in a previous randomized controlled trial assessing the benefit of supplementing nutrient-enriched formulas for LBW infants with arachidonic acid and docosahexaenoic acid. Infants (n = 463, birth weight, 750–1,800 g) were enrolled from nurseries located in Chile, the United Kingdom, and the United States. If human milk was fed before hospital discharge, it was fortified (3,050–3,300 kJ/L, 22–24 kcal/oz). As infants were weaned from human milk, they were fed nutrient-enriched formula with or without arachidonic and docosahexaenoic acids (3,300 kJ/L before term, 3,050 kJ/L thereafter) until 12 months CA. Formula fed infants were given nutrient-enriched formula with or without added arachidonic and docosahexaenoic acids (3,300 kJ/L to term, 3,050 kJ/L thereafter) until 12 months CA. For the purposes of this evaluation, infants were categorized into four mutually exclusive feeding groups: 1) predominantly human milk fed until term CA (PHM-T, n = 43); 2) ≥ 50% energy from human milk before hospital discharge (≥ 50% HM, n = 98); 3) < 50% of energy from human milk before hospital discharge (< 50% HM, n = 203); or 4) predominantly formula fed until term CA (PFF-T, n = 119). Results PFF-T infants weighed approximately 500 g more at term CA than did PHM-T infants. This absolute difference persisted until 6 months CA. PFF-T infants were also longer (1.0–1.5 cm) and had larger head circumferences (0.3–1.1 cm) than both PHM-T and ≥ 50% HM infants at term CA. There was a positive association between duration of human milk feeding and the Bayley Mental Index at 12 months CA (P = 0.032 full and P = 0.073 reduced, statistical models) after controlling for the confounding variables of home environment and maternal intelligence. Infants with chronic lung disease fed ≥ 50% HM until term CA (n = 22) had a mean Bayley Motor Index about 11 points higher at 12 months CA compared with infants PFF-T (n = 24, P = 0.033 full model). Conclusion Our data suggest that, despite a slower early growth rate, human milk fed LBW infants have development at least comparable to that of infants fed nutrient-enriched formula. Exploratory analysis suggests that some subgroups of human milk fed LBW infants may have enhanced development, although this needs to be confirmed in future studies.

Magnocellular and parvocellular contributions to backward masking dysfunction in schizophrenia

Patients with schizophrenia have repeatedly shown deficits in visual processing. These deficits have been well documented using visual backward masking (VBM). The VBM deficit in schizophrenia is thought to be due to aberrant interactions between magnocellular (M) and parvocellular (P) visual pathways. To date, no study has studied these claims with rigorous stimuli isolating M and P pathway responses. This study examined the function of each pathway and their interactions by creating M- and P-biased targets based on their known physiological properties. The M system responds to very low luminance contrast whereas the P system does not, and the P system responds to color contrast whereas the M system generally does not. Thus, to activate the P system, target letters and masks utilized color contrast, and to activate the M system, target letters and masks utilized very low luminance contrast. Four conditions were presented such that M- and P-biased targets were paired with both M- and P-biased masks. A significant Group x Mask Condition interaction was found when a P target was used in combination with an M or P mask, but not when an M target was used. In particular, schizophrenia patients needed significantly longer interstimulus intervals (ISIs) than controls to escape from masking in the P target/M mask condition, but not in any of the other three conditions. In addition, the critical stimulus durations (CSDs) for unmasked stimuli were significantly increased for both M and P targets in patients relative to controls. These findings demonstrate a significant impairment in M, but not P pathway, function in patients with schizophrenia. Furthermore, deficits of letter identification, including those of P targets, may also reflect impairment of the M pathway given the priming function of the dorsal stream.

Perception Measurement in Clinical Trials of Schizophrenia: Promising Paradigms From CNTRICS

The third meeting of the Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS) focused on selecting promising measures for each of the cognitive constructs selected in the first CNTRICS meeting. In the domain of perception, the 2 constructs of interest were gain control and visual integration. CNTRICS received 5 task nominations for gain control and three task nominations for visual integration. The breakout group for perception evaluated the degree to which each of these tasks met prespecified criteria. For gain control, the breakout group for perception believed that 2 of the tasks (prepulse inhibition of startle and mismatch negativity) were already mature and in the process of being incorporated into multisite clinical trials. However, the breakout group recommended that steady-state visual-evoked potentials be combined with contrast sensitivity to magnocellular vs parvocellular biased stimuli and that this combined task and the contrast-contrast effect task be recommended for translation for use in clinical trial contexts in schizophrenia research. For visual integration, the breakout group recommended the Contour Integration and Coherent Motion tasks for translation for use in clinical trials. This manuscript describes the ways in which each of these tasks met the criteria used by the breakout group to evaluate and recommend tasks for further development.

Sensory Contributions to Impaired Emotion Processing in Schizophrenia

Both emotion and visual processing deficits are documented in schizophrenia, and preferential magnocellular visual pathway dysfunction has been reported in several studies. This study examined the contribution to emotion-processing deficits of magnocellular and parvocellular visual pathway function, based on stimulus properties and shape of contrast response functions. Experiment 1 examined the relationship between contrast sensitivity to magnocellular- and parvocellular-biased stimuli and emotion recognition using the Penn Emotion Recognition (ER-40) and Emotion Differentiation (EMODIFF) tests. Experiment 2 altered the contrast levels of the faces themselves to determine whether emotion detection curves would show a pattern characteristic of magnocellular neurons and whether patients would show a deficit in performance related to early sensory processing stages. Results for experiment 1 showed that patients had impaired emotion processing and a preferential magnocellular deficit on the contrast sensitivity task. Greater deficits in ER-40 and EMODIFF performance correlated with impaired contrast sensitivity to the magnocellular-biased condition, which remained significant for the EMODIFF task even when nonspecific correlations due to group were considered in a step-wise regression. Experiment 2 showed contrast response functions indicative of magnocellular processing for both groups, with patients showing impaired performance. Impaired emotion identification on this task was also correlated with magnocellular-biased visual sensory processing dysfunction. These results provide evidence for a contribution of impaired early-stage visual processing in emotion recognition deficits in schizophrenia and suggest that a bottom-up approach to remediation may be effective.

Rehabilitation of intimacy and sexual dysfunction in couples with multiple sclerosis

Sexual dysfunction is a highly prevalent symptom of multiple sclerosis (MS), with little published research on effective treatments. This pilot study tested the efficacy of a counseling intervention in nine couples utilizing a quasi-experimental research design. The intervention consisted of 12 counseling sessions, communication with the MS medical treatment team, education, and tailoring symptomatic treatments so they interfere less with sexual function. Repeated measures analysis of variance indicated significant improvements in affective and problem-solving communication, marital satisfaction, and sexual satisfaction during the treatment vs. the waiting list phase of the study (F=1.7, P5.001). MS patients and their spouses reported similar levels of improvement.

Dysfunction of early-stage visual processing in schizophrenia: harmonic analysis

Schizophrenia is associated with severe neurocognitive deficits that constitute a core feature of the disorder. Deficits have been most extensively studied in relationship to higher-order processes. This study evaluated the integrity of early visual processing in order to evaluate the overall pattern of visual dysfunction in schizophrenia. Steady-state visual-evoked potentials (ssVEPs) were recorded over the occipital cortex (Oz) in patients with schizophrenia and schizoaffective disorder (N=26) and in age-matched comparison volunteers (N=22). Two stimuli were used: windmill-dartboard and partial-windmill, which are contrast-reversing ( approximately 4 Hz), radial patterns with dominant low spatial-frequency content. Each stimulus was presented for 1 min. Fourier analysis was performed on the ssVEP data to extract the relevant temporal frequency (i.e., harmonic) components. Magnitude-squared coherence (MSC) was computed to estimate the relative signal level for each frequency component. The patients showed reduced amplitude and coherence of second harmonic responses in both conditions, but intact first harmonic responses in the windmill-dartboard condition. This finding of a differential deficit may indicate a significant loss in the magnocellular pathway, which contributes to the generation of the second harmonic component under these conditions. Early sensory deficits may lead to impairments in subsequent stages of processing.

The Multiple Sclerosis Intimacy and Sexuality Questionnaire-19 (MSISQ-19)

The purpose of the present study was to develop a reliable and valid self-report questionnaire to assess the perceived influence of Multiple Sclerosis (MS) symptoms on sexual activity and satisfaction and the perceived influence of MS symptoms on the overall quality of intimate relationships. This instrument was called the Multiple Sclerosis Intimacy and Sexuality Questionnaire (MSISQ). The initial item pool consisted of 72 items reflecting primary, secondary, and tertiary sexual dysfunction. The MSISQ was revised by eliminating items assessing the impact of MS symptoms on the overall quality of intimate relationships because they were redundant with items assessing the impact of MS symptoms on sexual activity and satisfaction. Factor analysis, reliability analysis, and item analysis demonstrated that the MSISQ could be further shortened without diminishing the statistical integrity of the instrument. Hence, it was shortened to a 19-item questionnaire (MSISQ-19), with primary, secondary, and tertiary sexual dysfunction subscales. Reliability analyses provided evidence for high internal consistency for the total MSISQ-19 (α = .91) and for the primary(α = .82), secondary (α = .85) and tertiary (α = .87) subscales. The MSISQ-19 demonstrated concurrent validity with measures of: (1) marital satisfaction, specifically satisfaction with affective communication, problem solving communication, and sexual dissatisfaction, (2) neurological impairment and level of disability in MS, (3) psychological distress and well-being, and (4) global sexual dysfunction in MS. In addition, a comparison of the distribution of scores of the MSISQ-19 and the Sexual Function Scale (SFS) of the Minimal Record of Disability (MRD) in MS demonstrated that the MSISQ-19 was more sensitive to moderate and high levels of sexual difficulty. Study limitations, theoretical, clinical, and research implications, and directions for further research are discussed.

The relationship between religion and cardiovascular outcomes and all-cause mortality in the women's health initiative observational study

Some studies suggest that religiosity may be related to health outcomes. The current investigation, involving 92,395 Womens Health Initiative Observational Study participants, examined the prospective association of religious affiliation, religious service attendance, and strength and comfort from religion with subsequent cardiovascular outcomes and death. Baseline characteristics and responses to religiosity questions were collected at enrollment. Women were followed for an average of 7.7 years and outcomes were judged by physician adjudicators. Cox proportional regression models were run to obtain hazard ratios (HR) of religiosity variables and coronary heart disease (CHD) and death. After controlling for demographic, socioeconomic, and prior health variables, self-report of religious affiliation, frequent religious service attendance, and religious strength and comfort were associated with reduced risk of all-cause mortality [HR for religious affiliation = 0.84; 95% confidence interval (CI): 0.75–0.93] [HR for service attendance = 0.80; CI: 0.73–0.87] [HR for strength and comfort = 0.89; CI: 0.82–0.98]. However, these religion-related variables were not associated with reduced risk of CHD morbidity and mortality. In fact, self-report of religiosity was associated with increased risk of this outcome in some models. In conclusion, although self-report measures of religiosity were not associated with reduced risk of CHD morbidity and mortality, these measures were associated with reduced risk of all-cause mortality.

Luminance-contrast mechanisms in humans : Visual evoked potentials and a nonlinear model

Isolated-checks were luminance-modulated temporally to elicit VEPs. Bright or dark checks were used to drive ON or OFF pathways, and low or high-contrast conditions were used to emphasize activity from magnocellular or parvocellular pathways. Manipulation of stimulus parameters and frequency analysis of the VEP were performed to obtain spatial and contrast-response functions. A biophysical explanation is offered for why the opposite polarity stimuli drive selectively ON and OFF pathways in primary visual cortex, and a lumped biophysical model is proposed to quantify the data and characterize changes in the dynamics of the system with contrast given a limited number of parameters. Response functions were found to match the characteristics of the targeted pathways.

Posttraumatic growth, social support, and social constraint in hematopoietic stem cell transplant survivors

The relation between posttraumatic growth (PTG) and aspects of the social context, such as social support and social constraint, continues to be unclear in cancer survivors. Social cognitive processing theory is a useful framework for examining the effect of the social context on PTG. In theory, support interactions may either facilitate or hinder cognitive processing and thus lead to different PTG outcomes. The current study tested the hypothesis that emotional support and instrumental support would each explain a unique amount of the variance in PTG in distressed hematopoietic stem cell transplant (HSCT) survivors. Additionally, it was predicted that social constraint on cancer‐related disclosure would be negatively associated with PTG.