Beyond human-likeness: Socialness is more influential when attributing mental states to robots.

We sought to replicate and expand previous work showing that the more human-like a robot appears, the more willing people are to attribute mind-like capabilities and socially engage with it. Forty-two participants played games against a human, a humanoid robot, a mechanoid robot, and a computer algorithm while undergoing functional neuroimaging. We confirmed that the more human-like the agent, the more participants attributed a mind to them. However, exploratory analyses revealed that the perceived socialness of an agent appeared to be as, if not more, important for mind attribution. Our findings suggest top-down knowledge cues may be equally or possibly more influential than bottom-up stimulus cues when exploring mind attribution in non-human agents. While further work is now required to test this hypothesis directly, these preliminary findings hold important implications for robotic design and to understand and test the flexibility of human social cognition when people engage with artificial agents.

Exploring the relationship between anthropomorphism and theory-of-mind in brain and behaviour.

The process of understanding the minds of other people, such as their emotions and intentions, is mimicked when individuals try to understand an artificial mind. The assumption is that anthropomorphism, attributing human-like characteristics to non-human agents and objects, is an analogue to theory-of-mind, the ability to infer mental states of other people. Here, we test to what extent these two constructs formally overlap. Specifically, using a multi-method approach, we test if and how anthropomorphism is related to theory-of-mind using brain (Experiment 1) and behavioural (Experiment 2) measures. In a first exploratory experiment, we examine the relationship between dispositional anthropomorphism and activity within the theory-of-mind brain network (n = 108). Results from a Bayesian regression analysis showed no consistent relationship between dispositional anthropomorphism and activity in regions of the theory-of-mind network. In a follow-up, pre-registered experiment, we explored the relationship between theory-of-mind and situational and dispositional anthropomorphism in more depth. Participants (n = 311) watched a short movie while simultaneously completing situational anthropomorphism and theory-of-mind ratings, as well as measures of dispositional anthropomorphism and general theory-of-mind. Only situational anthropomorphism predicted the ability to understand and predict the behaviour of the film's characters. No relationship between situational or dispositional anthropomorphism and general theory-of-mind was observed. Together, these results suggest that while the constructs of anthropomorphism and theory-of-mind might overlap in certain situations, they remain separate and possibly unrelated at the personality level. These findings point to a possible dissociation between brain and behavioural measures when considering the relationship between theory-of-mind and anthropomorphism.

Brief report: Relationship between performance testing and parent report of attention and executive functioning profiles in children following perinatal arterial ischemic stroke.

Children with perinatal arterial ischemic stroke (PAIS) have increased rates of attention and executive functioning (EF) weaknesses. Research in other pediatric disorders has documented poor consistency between parent report of these skills and performance-based measures. We compared these data sources in children with PAIS. Forty full-term (≥37 weeks) children ages 3-16 (median = 7.2 years; 58% male) with PAIS completed neuropsychological testing and composite scores were created for seven attention and EF domains (Processing Speed; Attention; Working Memory; Verbal Retrieval; Inhibitory Control; Flexibility/Shifting; Planning). Parents completed "real-world" functioning questionnaires (ADHD Rating Scale-IV, BRIEF). Correlational analysis were used to compare parent and performance measures. Correlations between ADHD Rating Scale-IV scores and the performance-based Attention and Inhibition composite scores were nonsignificant. Significant negative correlations were found between the BRIEF GEC and performance-based Verbal Retrieval and Processing Speed composites, but remaining GEC/composite comparisons were nonsignificant. Analyses between parent report BRIEF index scores and the corresponding performance-based domain identified one significant negative correlation between the BRIEF Working Memory Index and the Working Memory composite score. While children with PAIS demonstrate difficulties in attention and EF on both parent report and performance measures, little significance was found in comparisons of these two types of measures. There may be several explanations for this dissociation: measures assessing different aspects of the same underlying construct; performance-based measures lacking ecological validity; and parents underestimating/underreporting their child's deficits. Thus, multiple sources of informant and performance data are necessary to make more accurate conclusions about functioning in these domains.

[Formula: see text]Attention and executive functioning profiles in children following perinatal arterial ischemic stroke.

Perinatal arterial ischemic stroke (PAIS) is a form of childhood stroke; the majority of those affected experience neurologic sequelae, including motor, language and neurocognitive impairments. This study examines the attention and executive functioning (EF) profiles of children following PAIS, as well as the impact of age and sex. In this single-center cross-sectional study, 40 children aged 3 to 16 years (median age 7.2 years; 58% male) who have suffered a PAIS underwent a comprehensive neuropsychological battery to assess attention and EF. Parents completed behavioral questionnaires regarding real-world functioning. Composite scores were calculated for seven attention and EF domains (Attention, Working Memory, Verbal Retrieval, Inhibitory Control, Flexibility/Shifting, Planning/Organization, and Processing Speed). The results for all measured domains of attention and EF are significantly lower in the participants compared to the normative samples (p < .001), with the exception of Working Memory. However, increasing difficulty with Working Memory is associated with developing age. Older age at time of testing is also associated with a higher incidence of clinically-elevated attention deficit hyperactivity disorder (ADHD) symptoms. Sex is not associated with performance measures or parental report of functioning. The participants demonstrate mild-to-moderate attention and EF impairment compared to the normative population. Clinicians, families, and educators should be informed about the neurocognitive sequelae of PAIS and the need for close developmental surveillance in this population to identify vulnerable children and initiate appropriate therapeutic interventions in a timely fashion.

Triglycerides are negatively correlated with cognitive function in nondemented aging adults.

OBJECTIVE: Vascular risk factors like hyperlipidemia may adversely affect brain function. We hypothesized that increased serum triglycerides are associated with decreased executive function and memory in nondemented elderly subjects. We also researched possible vascular mediators and white matter microstructure as assessed with diffusion tensor imaging (DTI). DESIGN/METHOD: Participants were 251 nondemented elderly adults (54% male) with a mean age of 78 (SD = 6.4; range: 62-94) years and a mean education of 15.6 (SD = 2.9; range: 8-23) years. Fasting blood samples were used to detect serum triglyceride and low-density lipoprotein (LDL) levels along with ApoE4 status. DTI was used to determine whole brain fractional anisotropy (FA). Composite executive and memory scores were derived from item response theory. Clinical Dementia Rating (CDR) scores provided informant-based measures of daily functioning. RESULTS: Triglyceride levels were inversely correlated with executive function, but there was no relationship with memory. Controlling for age, gender, and education did not affect this correlation. This relationship persisted after controlling for vascular risk factors like LDL, total cholesterol, CDR and ApoE4 status. Lastly, adding whole-brain FA to the model did not affect the correlation between triglycerides and executive function. CONCLUSION: Triglyceride levels are inversely correlated with executive function in nondemented elderly adults after controlling for age, education, gender, total cholesterol, LDL, ApoE4 status, CDR, and white-matter microstructure. The fact that the effect of triglycerides on cognition was not clearly mediated by vascular risks or cerebrovascular injury raises questions about widely held assumptions of how triglycerides might impact cognition function. (PsycINFO Database Record

Clinical Predictors of Attention and Executive Functioning Outcomes in Children After Perinatal Arterial Ischemic Stroke.

BACKGROUND: Children with perinatal arterial ischemic stroke (PAIS) are at risk for later neurocognitive and behavioral deficits, yet the clinical predictors of these outcomes are understudied. We examined the influence of clinical and infarct characteristics on attention and executive functioning in children following PAIS. METHODS: Forty children born at term (≥37 weeks' gestation) with PAIS (28 with neonatal arterial ischemic stroke and 12 with presumed PAIS) underwent a comprehensive neuropsychological battery at age three to 16 years (median age 7.2 years; 58% male) to assess attention and executive functioning. Parents also completed questionnaires regarding real-world functioning. Clinical variables including perinatal stroke subtype, infarct characteristics (location, laterality, and volume), and the presence of comorbid epilepsy were ascertained from the medical record. RESULTS: Presumed PAIS, larger infarct volume, and comorbid epilepsy negatively influenced the performance on attention and executive functioning measures. These clinical variables were also associated with greater functional problems on parent reports, including a higher frequency of attention-deficit/hyperactivity disorder symptoms and greater difficulties in some subdomains of executive functioning. Infarct location and laterality were not associated with performance measures or parental report of functioning. CONCLUSION: Although all children with PAIS are at risk for later deficits in attention and executive functioning, those with presumed PAIS, larger infarct size, and comorbid epilepsy appear to be the most vulnerable. As they approach and reach school age, these children should undergo neuropsychological assessment to ensure timely implementation of therapeutic interventions and behavioral strategies.

Pediatric cerebral sinovenous thrombosis following cranial surgery.

PURPOSE: Pediatric cerebral sinovenous thrombosis (CSVT) is an important, though less common subtype of pediatric stroke. It has been linked to several risk factors, including cranial procedures, with few studies highlighting this relationship. The aim of this study was to characterize the diagnosis and treatment of CSVT after cranial surgery. METHODS: An institutional pediatric stroke research database was used to identify all CSVT cases diagnosed within 30 days of cranial surgery from November 2004 to December 2014. Thirteen subjects were retrospectively analyzed for clinical presentation, surgical details, radiographic characteristics, laboratory study results, treatment, and outcome. Diagnostic testing and treatment adhered to a consensus-based institutional stroke protocol. RESULTS: Cranial vault reconstruction, subdural empyema evacuation, and tumor resection were each observed in three subjects. Eleven (85%) subjects had sinus exposure during surgery, and eight (73%) developed thrombus in a sinus within or adjacent to the operative field. Two (15%) had documented iatrogenic sinus injury. On post-operative testing, ten (77%) subjects had prothrombotic abnormalities. Seven (54%) were treated with anti-coagulation therapy (ACT) starting on a median of post-operative day (POD) 3 (IQR 1-3) for a median of 2.9 months (IQR 2.4-5.4). Median time to imaging evidence of partial or complete recanalization was 2.4 months (IQR 0.7-5.1). No symptomatic hemorrhagic complications were encountered. CONCLUSIONS: Pediatric CSVT may be encountered after cranial surgery, and decisions related to anti-coagulation are challenging. The risk of CSVT should be considered in pre-surgical planning and post-operative evaluation of cases with known risk factors. In our study, judicious use of ACT was safe in the post-operative period.

Incidence and predictors of epilepsy after pediatric arterial ischemic stroke.

OBJECTIVE: To determine the cumulative incidence and clinical predictors of remote symptomatic seizures and epilepsy after pediatric arterial ischemic stroke (AIS). METHODS: We performed a retrospective analysis of 218 participants with neonatal AIS (NAIS), presumed perinatal AIS (PPAIS), and childhood AIS (CAIS) from a single-center prospective consecutive cohort enrolled from 2006 to 2014. Medical records were reviewed for timing, semiology, and treatment of acute symptomatic seizures, remote symptomatic seizures (RSS), and epilepsy. Cumulative incidence of RSS and epilepsy were assessed using survival analysis. RESULTS: Acute symptomatic seizures occurred in 94% of NAIS (n = 70/74) and 17% of CAIS (n = 18/105). Younger children were more likely to present with seizures at stroke ictus, and acute symptomatic seizures were predictive of later RSS and epilepsy in CAIS. Median follow-up for the entire cohort was 34 months, interquartile range 44.9 months (16.3-61.2). Estimated cumulative incidence of RSS at 2 years was 19% in NAIS, 24% in PPAIS, and 7% in CAIS. Estimated cumulative incidence of epilepsy at 2 years was 11% in NAIS, 19% in PPAIS, and 7% in CAIS. The median time to these outcomes was <2 years in all stroke subtypes. Among participants developing epilepsy (n = 34), seizures were often well-controlled at last follow-up with median Engel class of ≤2 (<1 seizure/month). CONCLUSIONS: RSS and epilepsy are important neurologic sequelae of pediatric AIS. Children with perinatal stroke and CAIS with acute symptomatic seizures are at increased risk of these outcomes. These cohorts need further study to identify biomarkers and potential therapeutic targets for epileptogenesis.

MCP-1 and eotaxin-1 selectively and negatively associate with memory in MCI and Alzheimer's disease dementia phenotypes.

INTRODUCTION: MCP-1 and eotaxin-1 are encoded on chromosome 17 and have been shown to reduce hippocampal neurogenesis in mice. We investigated whether these chemokines selectively associate with memory in individuals with mild cognitive impairment (MCI) and Alzheimer's disease (AD) dementia. METHODS: MCP-1 and eotaxin-1 were assayed in controls, MCI, and AD dementia patients with varying phenotypes (n = 171). A subset of 55 individuals had magnetic resonance imaging (MRI) scans available. Composite scores for cognitive variables were created, and medial temporal lobe volumes were obtained. RESULTS: An interaction was noted between MCP-1 and eotaxin-1, such that deleterious associations with memory were seen when both chemokines were elevated. These associations remained significant after adding APOE genotype and comparison (non-chromosome 17) chemokines into the model. These chemokines predicted left medial temporal lobe volume and were not related to other cognitive domains. DISCUSSION: These results suggest a potentially selective role for MCP-1 and eotaxin-1 in memory dysfunction in the context of varied MCI and AD dementia phenotypes.

Nonlinear Effects of Noxious Thermal Stimulation and Working Memory Demands on Subjective Pain Perception.

OBJECTIVE: A bidirectional relationship between working memory (WM) and acute pain has long been assumed, but equivocal evidence exists regarding this relationship. This study characterized the relationship between WM and acute pain processing in healthy individuals using an adapted Sternberg WM task. DESIGN: Participants completed a Sternberg task while receiving noxious thermal stimulation. Participants received a pseudorandom presentation of four different temperatures (baseline temperatures and individually determined low-, medium-, and high-temperature stimuli) and four levels of Sternberg task difficulty (0-, 3-, 6-, and 9-letter strings). SUBJECTS: Twenty-eight healthy participants were recruited from Stanford University and the surrounding community to complete this study. RESULTS: A nonlinear interaction between intensity of thermal stimulation and difficulty of the Sternberg task was noted. Increased cognitive load from the Sternberg task resulted in increased perception of pain in low-intensity thermal stimulation but suppressed pain perception in high-intensity thermal stimulation. Thermal stimulation had no significant effect on participants' response time or accuracy on the Sternberg task regardless of intensity level. CONCLUSIONS: Pain perception appears to decrease as a function of WM load only for sufficiently noxious stimuli. However, increasing noxious stimuli did not affect cognitive performance. These complex relationships may reflect a shared cognitive space that can become "overloaded" with input of multiple stimuli of sufficient intensity.

Memory profiles in pathology or biomarker confirmed Alzheimer disease and frontotemporal dementia.

OBJECTIVE: We examined verbal list memory in participants with pathology-confirmed or biomarker-supported diagnoses to clarify inconsistencies in comparative memory performance. We hypothesized that Alzheimer disease (AD) participants would show more rapid forgetting, whereas behavioral-variant frontotemporal dementia (bvFTD) participants would show a more dysexecutive pattern. We also explored differences in medial temporal volumes, and relative frontal and medial temporal area contributions to memory consolidation. PARTICIPANTS AND METHODS: Participants had clinical diagnoses of AD and bvFTD who were pathologically confirmed at autopsy or supported with Pittsburgh compound B amyloid imaging. We used cognitive and imaging data collected at baseline visits for a sample of 26 participants with AD (mean age=63.7, education=16.2, Clinical Dementia Rating=0.8), 25 participants with bvFTD (mean age=60.7; education=15.7; CRD=1.1), and 25 healthy controls (mean age=65.6; education=17.5; Clinical Dementia Rating=0.2). RESULTS AND CONCLUSIONS: AD participants showed more rapid forgetting than bvFTD, and both groups showed more rapid forgetting than controls. In contrast, bvFTD did not conform to a more dysexecutive pattern of performance as patient groups committed similar number of intrusion errors and showed comparably low rates of improvement on cued recall and recognition trials. For patients with neuroimaging, there were no group differences in medial temporal volumes, which was the only significant predictor of consolidation for both dementia groups.

The role of carotid intima-media thickness in predicting longitudinal cognitive function in an older adult cohort.

BACKGROUND AND PURPOSE: Carotid atherosclerosis is a risk factor for cerebrovascular disease in older adults. Although age-related cognitive decline has been associated with cerebrovascular disease, not much is known about the consequences of carotid atherosclerosis on longitudinal cognitive function. This study examines the longitudinal relationship between atherosclerosis and cognition in a sample of non-demented older subjects using baseline measurements of carotid intima media thickness (CIMT) and annual cognitive measures of executive function (EXEC) and verbal memory (MEM). METHODS: Baseline measurements included CIMT derived from B-mode carotid artery ultrasound, structural T1-weighted images of white matter hypointensities (WMH), white matter lesions (WML), and cerebral infarct. Hypertension, low-density lipoprotein (LDL), diabetes, and waist to hip ratios (WHR) were included as covariates in our models to control for cerebrovascular risks and central adiposity. Annual composite scores of EXEC and MEM functions were derived from item response theory. Linear mixed models were used to model longitudinal cognitive change. RESULTS: A significant inverse relationship was found between baseline CIMT and annual EXEC score, but not annual MEM score. Subjects included in the highest 4th quartile of CIMT showed a rate of annual decline in EXEC score that was significant relative to subjects in lower quartile groups (p<0.01). The relationship between the 4th quartile of CIMT and annual EXEC score remained significant after independently adjusting for imaging measures of white matter injury and cerebral infarct. CONCLUSIONS: Older adult subjects with the highest index of CIMT showed an annual decline in EXEC scores that was significant relative to subjects with lower quartile measurements of CIMT, independent of our measures of white matter injury and cerebral infarct. Our findings suggest that elevated measures of CIMT may mark an atherosclerotic state, resulting in a decline in executive function and not memory in non-demented older adults.

Prescription opioid analgesics rapidly change the human brain.

Chronic opioid exposure is known to produce neuroplastic changes in animals; however, it is not known if opioids used over short periods of time and at analgesic dosages can similarly change brain structure in humans. In this longitudinal, magnetic resonance imaging study, 10 individuals with chronic low back pain were administered oral morphine daily for 1 month. High-resolution anatomical images of the brain were acquired immediately before and after the morphine administration period. Regional changes in gray matter volume were assessed on the whole brain using tensor-based morphometry, and those significant regional changes were then independently tested for correlation with morphine dosage. Thirteen regions evidenced significant volumetric change, and degree of change in several of the regions was correlated with morphine dosage. Dosage-correlated volumetric decrease was observed primarily in the right amygdala. Dosage-correlated volumetric increase was seen in the right hypothalamus, left inferior frontal gyrus, right ventral posterior cingulate, and right caudal pons. Follow-up scans that were conducted an average of 4.7 months after cessation of opioids demonstrated many of the morphine-induced changes to be persistent. In a separate study, 9 individuals consuming blinded placebo capsules for 6 weeks evidenced no significant morphologic changes over time. The results add to a growing body of literature showing that opioid exposure causes structural and functional changes in reward- and affect-processing circuitry. Morphologic changes occur rapidly in humans during new exposure to prescription opioid analgesics. Further research is needed to determine the clinical impact of those opioid-induced gray matter changes.