Kristen M. Krysko

The use of aftereffects in the study of relationships among emotion categories.

The perception of visual aftereffects has been long recognized, and these aftereffects reveal a relationship between perceptual categories. Thus, emotional expression aftereffects can be used to map the categorical relationships among emotion percepts. One might expect a symmetric relationship among categories, but an evolutionary, functional perspective predicts an asymmetrical relationship. In a series of 7 experiments, the authors tested these predictions. Participants fixated on a facial expression, then briefly viewed a neutral expression, then reported the apparent facial expression of the 2nd image. Experiment 1 revealed that happy and sad are opposites of one another; each evokes the other as an aftereffect. The 2nd and 3rd experiments reveal that fixating on any negative emotions yields an aftereffect perceived as happy, whereas fixating on a happy face results in the perception of a sad aftereffect. This suggests an asymmetric relationship among categories. Experiments 4-7 explored the mechanism driving this effect. The evolutionary and functional explanations for the category asymmetry are discussed.

A threat-detection advantage in those with autism spectrum disorders

Identifying threatening expressions is a significant social perceptual skill. Individuals with autism spectrum disorders (ASD) are impaired in social interaction, show deficits in face and emotion processing, show amygdala abnormalities and display a disadvantage in the perception of social threat. According to the anger superiority hypothesis, angry faces capture attention faster than happy faces in individuals with a history of typical development [Hansen, C. H., & Hansen, R. D. (1988). Finding the face in the crowd: An anger superiority effect. Journal of Personality and Social Psychology, 54(6), 917-924]. We tested threat detection abilities in ASD using a facial visual search paradigm. Participants were asked to detect an angry or happy face image in an array of distracter faces. A threat-detection advantage was apparent in both groups: participants showed faster and more accurate detection of threatening over friendly faces. Participants with ASD showed similar reaction time, but decreased overall accuracy compared to controls. This provides evidence for less robust, but intact or learned implicit processing of basic emotions in ASD.

Eye Direction, Not Movement Direction, Predicts Attention Shifts in Those with Autism Spectrum Disorders

Experiments suggesting that a change in eye gaze creates a reflexive attention shift tend to confound motion direction and terminal eye direction. However, motion and the onset of motion are known to capture attention. Current thinking about social cognition in autism suggests that there might be a deficit in responding to social (eye gaze) cues but not non-social (motion direction) cues, making the current study theoretically critical. We report an experiment in which motion direction and eye direction are decoupled in order to determine which predicts attention shifts in adults with and without autism. In the Eye Movement condition the eyes moved towards or away from a target. In the Face Movement condition the face image shifted while pupils remained stationary on the screen, resulting in terminal eye gaze and motion being in opposite directions. Reflexive attention shifts in both groups followed terminal eye direction, rather than direction of movement.

The Toronto Observational Study of Natalizumab in Multiple Sclerosis

BACKGROUND Natalizumab is indicated for the treatment of relapsing multiple sclerosis (MS) with insufficient response to first-line disease-modifying therapy (DMT). We studied the efficacy of natalizumab for treatment of MS in a single centre observational design. METHODS A retrospective observational study of 146 patients [66% female; mean age 37.4; 72% relapsing remitting MS (RRMS), 28% secondary progressive MS (SPMS)] referred for natalizumab treatment at St. Michaels Hospital MS Clinic between 2007 and August 2009. Data included demographic, clinical (Expanded Disability Status Scale (EDSS) and annualized relapse rate (ARR)) and patient self-report measures. RESULTS The mean duration of treatment was 20 months in those treated with natalizumab and 97% had received prior DMTs. Eighty-three patients (57%) received at least 12 months of natalizumab treatment. In those who received at least 12 months of treatment, baseline ARR and EDSS were 1.6 and 2.7 in RRMS patients versus 1.0 and 5.4 in SPMS with relapses. The ARR decreased with natalizumab treatment to 0.38 (76% reduction, p<0.001) in RRMS versus 0.32 in SPMS patients (68% reduction, p=0.01). There was a treatment associated 11% reduction in EDSS to 2.4 (p=0.04) in RRMS, but no significant change in SPMS. Eighty-five percent of patients reported improved overall quality of life (QOL) and 62% indicated improved energy. CONCLUSIONS There was a major reduction in relapse rate, stabilization in EDSS and improvement in QOL and energy in some patients on natalizumab, all similar to treatment effects in the pivotal trial.

Identifying individuals with multiple sclerosis in an electronic medical record.

Background: The increasing use of electronic medical records (EMRs) presents an opportunity to efficiently evaluate and improve quality of care for individuals with MS. Objectives: We aimed to establish an algorithm to identify individuals with MS within EMRs. Methods: We used a sample of 73,003 adult patients from 83 primary care physicians in Ontario using the Electronic Medical Record Administrative data Linked Database (EMRALD). A reference standard of 247 individuals with MS was identified through chart abstraction. The accuracy of identifying individuals with MS in an EMR was assessed using information in the cumulative patient profile (CPP), prescriptions and physician billing codes. Results: An algorithm identifying MS in the CPP performed well with 91.5% sensitivity, 100% specificity, 98.7% PPV and 100% NPV. The addition of prescriptions for MS-specific medications and physician billing code 340 used four times within any 12-month timeframe slightly improved the sensitivity to 92.3% with a PPV of 97.9%. Conclusions: Data within an EMR can be used to accurately identify patients with MS. This study has positive implications for clinicians, researchers and policy makers as it provides the potential to identify cohorts of MS patients in the primary care setting to examine quality of care.

The face in the crowd effect: Threat-detection advantage with perceptually intermediate distractors

The ability to quickly perceive threatening facial expressions allows one to detect emotional states and respond appropriately. The anger superiority hypothesis predicts that angry faces capture attention faster than happy faces. Previous studies have used photographic (Hansen & Hansen, 1988) and schematic face images (e.g., Eastwood, Smilek, & Merikle, 2001; Ohman, Lunqvist, & Esteves, 2001) in studying the anger superiority effect, but specific confounds due to the construction of stimuli have led to conflicting findings. In the current study, participants performed a visual search for either angry or happy target faces among crowds of novel, perceptually intermediate morph distractors. A threat-detection advantage was evident where participants showed faster reaction times and greater accuracy in detecting angry over happy faces. Search slopes, however, did not significantly differ. Results suggest a threat-detection advantage mediated by serial rather than preattentive processing.

Quality of Life, Cognition and Mood in Adults with Pediatric Multiple Sclerosis.

BACKGROUND Pediatric onset multiple sclerosis (MS) negatively affects cognitive function, mood and health related quality of life (HRQOL). We aimed to explore the cognitive, psychological and HRQOL impacts of pediatric MS on young adults and to explore the relationships between disability, disease duration, cognition, mood and HRQOL in this hypotheses generating study. METHODS Thirty-four young adults with pediatric onset MS at St. Michaels Hospital in Toronto were included in this cross-sectional study (mean age 21.3 years, 56% female). Participants completed assessments of physical disability (Expanded Disability Status Scale (EDSS)), cognitive function (Symbol Digit Modalities Test (SDMT)), mood (Beck Depression Inventory II (BDI-II)), and HRQOL (Short Form Health Survey (SF-36v2)). Findings were compared to age- and gender- matched normative data. RESULTS Individuals with pediatric MS performed worse on the SDMT compared to normative data, with 53% demonstrating cognitive impairment. There was no difference in BDI-II scores from normative data, but 21% showed at least mild depression. There was a non-significant impairment in physical HRQOL compared to normative data. Decreased physical HRQOL was related to disability (EDSS), while mental HRQOL was related to depression (BDI-II). CONCLUSIONS Young adults with pediatric MS have reduced cognitive function. Non-significant reductions in HRQOL may be partly attributed to physical disability and depression. These factors should be addressed in the care of adults with pediatric MS. Further studies including control groups and longitudinal design are needed to confirm these findings.

Temporal trends in multiple sclerosis prevalence and incidence in a large population

Objective We sought to better understand the reasons for increasing prevalence of multiple sclerosis (MS) by studying prevalence in relation to incidence, mortality rates, sex ratio, and geographic distribution of cases. Methods We identified MS cases from 1996 to 2013 in Ontario, Canada, by applying a validated algorithm to health administrative data. We calculated age- and sex-standardized prevalence and incidence rates for the province and by census division. Incidence and prevalence sex ratios for women to men were computed. Results The prevalence of MS increased by 69% from 1.57 (95% confidence interval [CI]: 1.54–1.59) per 1,000 in 1996 (n = 12,155) to 2.65 (95% CI: 2.62–2.68) in 2013 (n = 28,192). Incidence remained relatively stable except for a spike in 2010, followed by a subsequent decline in 2011–2013, particularly among young people and men. Mortality decreased by 33% from 26.7 (95% CI: 23.5–30.3) per 1,000 to 18.0 (95% CI: 16.4–19.8) per 1,000. The incidence sex ratio was stable from 1996 to 2009, then declined in 2010, with partial rebound by 2013. MS prevalence and incidence showed no consistent association with latitude. Conclusion In this large, population-based MS cohort, we found stable incidence and increasing prevalence of MS; the latter largely reflected declining mortality. A spike in incidence in 2010 among younger patients and men at a time of widespread media coverage of MS suggests that these groups may be vulnerable to delayed diagnosis. We did not find a latitudinal gradient; however, most Ontarians live between the 42nd and 46th parallels, reducing our ability to detect an effect of latitude.

Recurrent Alternate-Sided Homonymous Hemianopia Due to Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke-Like Episodes (MELAS): A Case Report

ABSTRACT Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) can rarely cause alternate-sided homonymous hemianopia due to stroke-like episodes involving the occipital lobes, as reported in three previously published cases. The authors report an interesting case of a 16-year-old presenting with myoclonic epilepsy due to MELAS with the rare ND3 mitochondrial mutation T10191C, with recurrent alternate-sided homonymous hemianopia. Visual field and corresponding magnetic resonance imaging (MRI) findings are presented. To the authors’ knowledge, this is the first report of recurrent alternate-sided homonymous hemianopia in MELAS with documented visual field and MRI findings with resolution between each episode.

Measuring Disability Progression with the Multiple Sclerosis Functional Composite

The multiple sclerosis functional composite (MSFC) is a three-part quantitative objective measure of neurologic function, measuring leg (timed 25-foot walk [25FTW]), arm (nine-hole peg test [9HPT]), and cognitive (three-second paced auditory serial addition test [PASAT3]) function. The MSFC was developed to be a more sensitive measure of disability than the expanded disability status scale (EDSS) and has excellent reliability. Validity is supported by moderately strong correlations with EDSS, brain atrophy, and quality of life. Advantages of the MSFC include its continuous scale and inclusion of several disease dimensions. Limitations include practice effects, the lack of a visual function component, variations in reference populations, and limited understanding of clinically relevant MSFC z-score changes. MSFC z-score change has been used as a secondary end-point in MS trials, but EDSS progression remains the primary disability outcome. A new approach to MSFC data involves defining MSFC progression as worsening in an MSFC component by 15–20% over three months. With further study, this could be used as a primary disability outcome in future clinical trials.