Jennifer L. Barnes

Self-Referential Cognition and Empathy in Autism

Background Individuals with autism spectrum conditions (ASC) have profound impairments in the interpersonal social domain, but it is unclear if individuals with ASC also have impairments in the intrapersonal self-referential domain. We aimed to evaluate across several well validated measures in both domains, whether both self-referential cognition and empathy are impaired in ASC and whether these two domains are related to each other. Methodology/Principal Findings Thirty adults aged 19-45, with Asperger Syndrome or high-functioning autism and 30 age, sex, and IQ matched controls participated in the self-reference effect (SRE) paradigm. In the SRE paradigm, participants judged adjectives in relation to the self, a similar close other, a dissimilar non-close other, or for linguistic content. Recognition memory was later tested. After the SRE paradigm, several other complimentary self-referential cognitive measures were taken. Alexithymia and private self-consciousness were measured via self-report. Self-focused attention was measured on the Self-Focus Sentence Completion task. Empathy was measured with 3 self-report instruments and 1 performance measure of mentalizing (Eyes test). Self-reported autistic traits were also measured with the Autism Spectrum Quotient (AQ). Although individuals with ASC showed a significant SRE in memory, this bias was decreased compared to controls. Individuals with ASC also showed reduced memory for the self and a similar close other and also had concurrent impairments on measures of alexithymia, self-focused attention, and on all 4 empathy measures. Individual differences in self-referential cognition predicted mentalizing ability and self-reported autistic traits. More alexithymia and less self memory was predictive of larger mentalizing impairments and AQ scores regardless of diagnosis. In ASC, more self-focused attention is associated with better mentalizing ability and lower AQ scores, while in controls, more self-focused attention is associated with decreased mentalizing ability and higher AQ scores. Increasing private self-consciousness also predicted better mentalizing ability, but only for individuals with ASC. Conclusions/Significance We conclude that individuals with ASC have broad impairments in both self-referential cognition and empathy. These two domains are also intrinsically linked and support predictions made by simulation theory. Our results also highlight a specific dysfunction in ASC within cortical midlines structures of the brain such as the medial prefrontal cortex.

Expectations about numerical events in four lemur species (Eulemur fulvus, Eulemur mongoz, Lemur catta and Varecia rubra)

Although much is known about how some primates—in particular, monkeys and apes—represent and enumerate different numbers of objects, very little is known about the numerical abilities of prosimian primates. Here, we explore how four lemur species (Eulemur fulvus, E. mongoz, Lemur catta, and Varecia rubra) represent small numbers of objects. Specifically, we presented lemurs with three expectancy violation looking time experiments aimed at exploring their expectations about a simple 1+1 addition event. In these experiments, we presented subjects with displays in which two lemons were sequentially added behind an occluder and then measured subjects’ duration of looking to expected and unexpected outcomes. In experiment 1, subjects looked reliably longer at an unexpected outcome of only one object than at an expected outcome of two objects. Similarly, subjects in experiment 2 looked reliably longer at an unexpected outcome of three objects than at an expected outcome of two objects. In experiment 3, subjects looked reliably longer at an unexpected outcome of one object twice the size of the original than at an expected outcome of two objects of the original size. These results suggest that some prosimian primates understand the outcome of simple arithmetic operations. These results are discussed in light of similar findings in human infants and other adult primates.

‘Unwilling’ versus ‘unable’: capuchin monkeys’ (Cebus apella) understanding of human intentional action

A sensitivity to the intentions behind human action is a crucial developmental achievement in infants. Is this intention reading ability a unique and relatively recent product of human evolution and culture, or does this capacity instead have roots in our non-human primate ancestors? Recent work by Call and colleagues (2004) lends credence to the latter hypothesis, providing evidence that chimpanzees are also sensitive to human intentions. Specifically, chimpanzees remained in a testing area longer and exhibited fewer frustration behaviors when an experimenter behaved as if he intended to give food but was unable to do so, than when the experimenter behaved as if he had no intention of giving food. The present research builds on and extends this paradigm, providing some of the first evidence of intention reading in a more distant primate relative, the capuchin monkey (Cebus apella). Like chimpanzees, capuchin monkeys distinguish between different goal-directed acts, vacating an enclosure sooner when an experimenter acts unwilling to give food than when she acts unable to give food. Additionally, we found that this pattern is specific to animate action, and does not obtain when the same actions are performed by inanimate rods instead of human hands (for a similar logic, see Woodward, 1998). Taken together with the previous evidence, the present research suggests that our own intention reading is not a wholly unique aspect of the human species, but rather is shared broadly across the primate order.

Helping behaviour and regard for others in capuchin monkeys (Cebus apella)

Altruism is an evolutionary puzzle. To date, much debate has focused on whether helping others without regard to oneself is a uniquely human behaviour, with a variety of empirical studies demonstrating a lack of altruistic behaviour in chimpanzees even when the demands of behaving altruistically seem minimal. By contrast, a recent experiment has demonstrated that chimpanzees will help a human experimenter to obtain an out-of-reach object, irrespective of whether or not they are offered a reward for doing so, suggesting that the cognitions underlying altruistic behaviour may be highly sensitive to situational demands. Here, we examine the cognitive demands of other-regarding behaviour by testing the conditions under which primates more distantly related to humans—capuchin monkeys—help an experimenter to obtain an out-of-reach object. Like chimpanzees, capuchin monkeys helped human experimenters even in the absence of a reward, but capuchins systematically failed to take into account the perspective of others when they stood to obtain food for themselves. These results suggest an important role for perspective taking and inhibition in altruistic behaviour and seem to reflect a significant evolutionary development in the roots of altruism, and specifically in other-regarding behaviour, between the divergence of New World monkeys and apes.

The Big Picture: Storytelling Ability in Adults with Autism Spectrum Conditions

Previous work on story-telling ability in autism spectrum conditions (ASC) has found a pattern of relatively intact use of story grammar in ASC narratives; however, prior analysis has concentrated primarily on whether specific story components are included, rather than how they are included. The present study analyzes an existing narrative dataset, concentrating on the kind of information that individuals with and without high functioning autism or Asperger syndrome include about story elements such as setting, character, conflict, and resolution. This analysis showed that individuals with ASC are biased toward providing local over global details about each element, regardless of whether the element involved mental content. These results are discussed in terms of the Weak Central Coherence and Hyper-Systemizing theories.

Intestinal Adaptation Is Stimulated by Partial Enteral Nutrition Supplemented With the Prebiotic Short-Chain Fructooligosaccharide in a Neonatal Intestinal Failure Piglet Model

BACKGROUND Butyrate has been shown to stimulate intestinal adaptation when added to parenteral nutrition (PN) following small bowel resection but is not available in current PN formulations. The authors hypothesized that pre- and probiotic administration may be a clinically feasible method to administer butyrate and stimulate intestinal adaptation. METHODS AND MATERIALS Neonatal piglets (48 hours old, n = 87) underwent placement of a jugular catheter and an 80% jejunoileal resection and were randomized to one of the following treatment groups: control (20% standard enteral nutrition/80% standard PN), control plus prebiotic (10 g/L short-chain fructooligosaccharides [scFOS]), control plus probiotic (1 × 10(9) CFU Lactobacillus rhamnosus GG [LGG]), or control plus synbiotic (scFOS + LGG). Animals received infusions for 24 hours, 3 days, or 7 days, and markers of intestinal adaptation were assessed. RESULTS Prebiotic treatment increased ileal mucosa weight compared with all other treatments (P = .017) and ileal protein compared with control (P = .049), regardless of day. Ileal villus length increased in the prebiotic and synbiotic group (P = .011), regardless of day, specifically due to an increase in epithelial proliferation (P = .003). In the 7-day prebiotic group, peptide transport was upregulated in the jejunum (P = .026), whereas glutamine transport was increased in both the jejunum and colon (P = .001 and .003, respectively). CONCLUSIONS Prebiotic and/or synbiotic supplementation resulted in enhanced structure and function throughout the residual intestine. Identification of a synergistic prebiotic and probiotic combination may enhance the promising results obtained with prebiotic treatment alone.

CSF from Parkinson disease patients differentially affects cultured microglia and astrocytes.

BackgroundExcessive and abnormal accumulation of alpha-synuclein (α-synuclein) is a factor contributing to pathogenic cell death in Parkinsons disease. The purpose of this study, based on earlier observations of Parkinsons disease cerebrospinal fluid (PD-CSF) initiated cell death, was to determine the effects of CSF from PD patients on the functionally different microglia and astrocyte glial cell lines. Microglia cells from human glioblastoma and astrocytes from fetal brain tissue were cultured, grown to confluence, treated with fixed concentrations of PD-CSF, non-PD disease control CSF, or control no-CSF medium, then photographed and fluorescently probed for α-synuclein content by deconvolution fluorescence microscopy. Outcome measures included manually counted cell growth patterns from day 1-8; α-synuclein density and distribution by antibody tagged 3D model stacked deconvoluted fluorescent imaging.ResultsAfter PD-CSF treatment, microglia growth was reduced extensively, and a non-confluent pattern with morphological changes developed, that was not evident in disease control CSF and no-CSF treated cultures. Astrocyte growth rates were similarly reduced by exposure to PD-CSF, but morphological changes were not consistently noted. PD-CSF treated microglia showed a significant increase in α-synuclein content by day 4 compared to other treatments (p ≤ 0.02). In microglia only, α-synuclein aggregated and redistributed to peri-nuclear locations.ConclusionsCultured microglia and astrocytes are differentially affected by PD-CSF exposure compared to non-PD-CSF controls. PD-CSF dramatically impacts microglia cell growth, morphology, and α-synuclein deposition compared to astrocytes, supporting the hypothesis of cell specific susceptibility to PD-CSF toxicity.

Consideration of nutrient levels in studies of cognitive decline

Epidemiological studies suggest that certain micronutrients may improve or maintain cognitive function. Consistent demonstration of benefits in intervention trials has been elusive, possibly because most intervention trials do not select subjects on the basis of nutrient status and/or intake. The objective of this review was to identify levels of intake or markers of nutrient insufficiency that define at-risk older adult populations to determine whether these populations will benefit from nutritional intervention. This review examines evidence from interventional and prospective observational studies that evaluated the effects of folate, vitamin B12 , and vitamin E on cognitive decline in older populations. The studies suggest that supplementation may protect against cognitive decline when serum folate is <12 nmol/L or vitamin E intake is <6.1 mg/day. The literature is inadequate to define a level for vitamin B12 . Epidemiological studies investigating the relations of nutrients to cognitive decline should consider nutrient status in the reporting and interpretation of results. Randomized trials should design inclusion and exclusion criteria to select individuals with low intake and to disallow multivitamin intake. These recommendations may be useful for the design of valid trials and to advance the current understanding of nutrition and neurological diseases.

Modified Nutritional Recommendations to Improve Dietary Patterns and Outcomes in Hemodialysis Patients

The renal diet has traditionally been regarded as one of the most complex medical nutrition therapies to teach, understand, and implement. Specifically, patients are instructed to limit fruits, vegetables, nuts, legumes, dairy, and whole grains because of both phosphorus and potassium concerns. Furthermore, hemodialysis patients are often encouraged to decrease fluid intake to control interdialytic weight gain. These restrictions can result in frustration, lack of autonomy, and the perception that there is nothing left to eat. It is possible that the traditional renal diet may be liberalized, with a focus on whole foods low in sodium and phosphorus additives, to afford patients greater choices and ultimately improved outcomes. Therefore, the objective of this review is to concisely assess the evidence in support of a renal diet focused primarily on reducing the intake of sodium and inorganic phosphorus. Finally, the limited evidence for restrictions on dietary potassium intake is summarized.

Transcranial magnetic stimulation for treatment-resistant depression: Naturalistic treatment outcomes for younger versus older patients.

BACKGROUND Repetitive transcranial magnetic stimulation (TMS) has been shown to be safe and effective for treatment-resistant depression (TRD) in the general adult population. Efficacy among older (≥60 years) patients, who have a greater burden of cognitive, physical, and functional impairment compared to their younger counterparts, remains unclear. The current study aimed to characterize antidepressant response to an acute course of TMS therapy among patients aged ≥60 years compared to those <60 years in naturalistic clinical practice settings. METHODS Data were retrospectively collected and pooled for adults with TRD (N =231; n =75 aged ≥60 years and n = 156 <60 years) who underwent an acute course of outpatient TMS therapy at two outpatient clinics. Self-report depression scales were administered at baseline and end of acute treatment. Change on continuous measures and categorical outcomes were compared across older vs. younger patients. RESULTS Both age groups showed significant improvements in depression symptoms. Response and remission rates did not differ between groups. Age group was not a significant predictor of change in depression severity, nor of clinical response or remission, in a model controlling for other predictors (all p>.05). LIMITATIONS Limitations include reliance on self-report clinical measures and variability in comorbidity and concurrent pharmacotherapy due to the naturalistic nature of the study. CONCLUSIONS Results suggest that effectiveness of TMS for TRD is not differentially modified by age. Based on these naturalistic data, age alone should not be considered a contraindication or poor prognostic indicator of the antidepressant efficacy of TMS.