Chronic ecologically relevant stress effects on reverse-translated touchscreen assays of reward responsivity and attentional processes in male rats: Implications for depression.

Stagnation in the development of novel therapeutic strategies for treatment-resistant depression has encouraged continued interest in improving preclinical methods. One tactic prioritizes the reverse translation of behavioral tasks developed to objectively quantify depressive phenotypes in patient populations for their use in laboratory animals via touchscreen technology. After cross-species concordance in task outcomes under healthy conditions is confirmed, construct validity can be further enhanced by identifying environmental stressors that reliably produce deficits in task performance that resemble those in depressive participants. The present studies characterized in male rats the ability of two chronic ecologically relevant stressors, inescapable ice water or isolated restraint, to produce depressive-like behavioral phenotypes in the Probabilistic Reward Task (PRT) and Psychomotor Vigilance Task (PVT). These tasks previously have been reverse-translated using touchscreen technology for rodents and nonhuman primates to objectively quantify, respectively, reward responsivity (anhedonia) and attentional processes (impaired cognitive function), each of which are core features of major depressive disorder. In the PRT, both inescapable ice water and isolated restraint produced persistent anhedonic phenotypes compared to non-stressed control performance (i.e., significantly blunted response bias for the richly rewarded stimulus). In the PVT, both chronic stressors impaired attentional processing, revealed by increases in titrated reaction times; however, these deficits largely subsided by the end of the chronic condition. Taken together, these findings confirm the ability of reverse-translated touchscreen tasks to effectively generate behavioral phenotypes that exhibit expected deficits in performance outcomes following exposure to chronic ecologically relevant stress. In turn, this approach is well positioned to appraise the ability of candidate therapeutics to attenuate or reverse such behavioral deficits and, thereby, contribute to preclinical medications development for treatment-resistant depression.

Moving toward reality: Electrocortical reactivity to naturalistic multimodal emotional videos.

While previous research has investigated the effects of emotional videos on peripheral physiological measures and conscious experience, this study extends the research to include electrocortical measures, specifically the steady-state visual-evoked potential (ssVEP). A carefully curated set of 45 videos, designed to represent a wide range of emotional and neutral content, were presented with a flickering border. The videos featured a continuous single-shot perspective, natural soundtrack, and excluded elements associated with professional films, to enhance realism. The results demonstrate a consistent reduction in ssVEP amplitude during emotional videos which strongly correlates with the rated emotional intensity of the clips. This suggests that narrative audiovisual stimuli have the potential to track dynamic emotional processing in the cortex, providing new avenues for research in affective neuroscience. The findings highlight the potential of using realistic video stimuli to investigate how the human brain processes emotional events in a paradigm that increases ecological validity. Future studies can further develop this paradigm by expanding the video set, targeting specific cortical networks, and manipulating narrative predictability. Overall, this study establishes a foundation for investigating emotional perception using realistic video stimuli and has the potential to expand our understanding of real-world emotional processing in the human brain.

Six elements test vs D-KEFS: what does "Ecological Validity" tell us?

OBJECTIVE: Extensive research shows that tests of executive functioning (EF) predict instrumental activities of daily living (IADLs) but are nevertheless often criticized for having poor ecological validity. The Modified Six Elements Test (MSET) is a pencil-and-paper test that was developed to mimic the demands of daily life, with the assumption that this would result in a more ecologically valid test. Although the MSET has been extensively validated in its ability to capture cognitive deficits in various populations, support for its ability to predict functioning in daily life is mixed. This study aimed to examine the MSET's ability to predict IADLs assessed via three different modalities relative to traditional EF measures. METHOD: Participants (93 adults aged 60 - 85) completed the MSET, traditional measures of EF (Delis-Kaplan Executive Function System; D-KEFS), and self-reported and performance-based IADLs in the lab. Participants then completed three weeks of IADL tasks at home, using the Daily Assessment of Independent Living and Executive Skills (DAILIES) protocol. RESULTS: The MSET predicted only IADLs completed at home, while the D-KEFS predicted IADLs across all three modalities. Further, the D-KEFS predicted home-based IADLs beyond the MSET when pitted against each other, whereas the MSET did not contribute beyond the D-KEFS. CONCLUSIONS: Traditional EF tests (D-KEFS) appear to be superior to the MSET in predicting IADLs in community-dwelling older adults. The present results argue against replacing traditional measures with the MSET when addressing functional independence of generally high-functioning and cognitive healthy older adult patients.

Ecological validity of cognitive fluctuations in dementia with Lewy bodies.

OBJECTIVES: Cognitive fluctuations are a core clinical feature of dementia with Lewy bodies (DLB), but their contribution to the everyday functioning difficulties evident DLB are not well understood. The current study evaluated whether intraindividual variability across a battery of neurocognitive tests (intraindividual variability-dispersion) and daily cognitive fluctuations as measured by informant report are associated with worse daily functioning in DLB. METHODS: The study sample included 97 participants with consensus-defined DLB from the National Alzheimer's Coordinating Center (NACC). Intraindividual variability-dispersion was measured using the coefficient of variation, which divides the standard deviation of an individual's performance scores across 12 normed neurocognitive indices from the NACC neuropsychological battery by that individual's performance mean. Informants reported on daily cognitive fluctuations using the Mayo Fluctuations Scale (MFS) and on daily functioning using the functional activities questionnaire (FAQ). RESULTS: Logistic regression identified a large univariate association of intraindividual variability-dispersion and presence of daily cognitive fluctuations on the MFS (Odds Ratio = 73.27, 95% Confidence Interval = 1.38, 3,895.05). Multiple linear regression demonstrated that higher intraindividual variability-dispersion and presence of daily cognitive fluctuations as assessed by the MFS were significantly and independently related to worse daily functioning (FAQ scores). CONCLUSIONS: Among those with DLB, informant-rated daily cognitive fluctuations and cognitive fluctuations measured in the clinic (as indexed by intraindividual variability-dispersion across a battery of tests) were independently associated with poorer everyday functioning. These data demonstrate ecological validity in measures of cognitive fluctuations in DLB.

Determinants of Social Cognitive Aging: Predicting Resilience and Risk.

This review focuses on conceptual and empirical research on determinants of social cognitive aging. We present an integrated model [the social cognitive resource (SCoRe) framework] to organize the literature and describe how social cognitive resilience is determined jointly by capacity and motivational resources. We discuss how neurobiological aging, driven by genetic and environmental influences, is associated with broader sensory, neural, and physiological changes that are direct determinants of capacity as well as indirect determinants of motivation via their influence on expectation of loss versus reward and cognitive effort valuation. Research is reviewed that shows how contextual factors, such as relationship status, familiarity, and practice, are fundamental to understanding the availability of both types of resource. We conclude with a discussion of the implications of social cognitive change in late adulthood for everyday social functioning and with recommendations for future research.

Ecological validity of performance-based cognitive screeners in amyotrophic lateral sclerosis: preliminary evidence.

BACKGROUND: This study aimed at preliminarily assessing, in a cohort of non-demented amyotrophic lateral sclerosis (ALS) patients, the ecological validity, and more specifically the veridicality, of the Edinburgh Cognitive and Behavioural ALS Screen (ECAS) and the ALS Cognitive Behavioral Screen (ALS-CBS™), by relating their scores to caregiver-report ratings of cognitive changes. METHODS: N = 147 patient-caregiver dyads were recruited. Patients were administered the ECAS and ALS-CBS™, whilst caregiver the Caregiver Behavioral Questionnaire (CBQ) and Beaumont Behavioural Inventory (BBI). An Ecological Cognitive Functioning Index (ECFI) was derived from those items of the CBQ and BBI that tap on executive and language changes. Ecological validity was assessed via both correlational and predictive analyses net of caregiver-rated behavioural changes (as assessed by the ECAS-Carer Interview). RESULTS: The ECFI was associated with the total scores on both the ECAS (p = .014) and ALS-CBS™ (p = .017). When looking at ECAS and ALS-CBS™ subscales, those assessing verbal fluency were selectively associated with the ECFI. The ECFI was higher in patients performing defectively on the ECAS (p = .004) and on the ALS-CBS™ (p = .027). DISCUSSION: This study suggests that both the ECAS and the ALS-CBS™ represent a valid estimate of non-demented ALS patients' cognitive status in the real world, also highlighting the clinical relevance of cognitive changes reported by caregivers.

Development of a real-world simulated instrument for evaluating visuospatial working memory: a preliminary psychometric study on older adults.

BACKGROUND: A prevalent challenge in neuropsychological assessment, particularly when utilizing instruments designed for controlled laboratory environments, is that the outcomes may not correspond to an individual's real-life status. Accordingly, assessments of visuospatial working memory (VSWM) conducted in such settings might fail to capture certain facets of this function, as it operates in real life. On the other hand, entirely ecological assessments may risk compromising internal validity. This study aimed to develop an intermediate mode of assessment that measures VSWM in older adults by employing a setting, a task, and a response format that aligns closely with both laboratory and ecological assessments. Furthermore, a preliminary investigation was carried out to study the variations in spatial cognition among different demographic groups. METHODS: In a two-session study, 77 healthy older adults, eight patients with mild cognitive impairment (MCI), and seven patients with Alzheimer's disease (AD) were recruited to complete the wayfinding questionnaire (WQ), the Corsi block-tapping task (CBTT), and the Spatial Memory Table (SMT). The SMT is a novel instrument developed specifically for this study, aiming to provide a more accurate measure of VSWM performance in older adults' everyday life. Test-retest and split-half reliabilities, as well as the face, content, concurrent, convergent, and known-groups validities, were analyzed to investigate the psychometric properties of the SMT. RESULTS: The analyses were mainly centered on studying the psychometric properties of the SMT. Test-retest reliability (r = .753, p < .001) and split-half reliability (ρSC = 0.747) were found to be acceptable. Concurrent validity using CBTT (r = .264, p = .021), convergent validity using WQ subscales (navigation and orientation: r = .282, p = .014; distance estimation: r = .261, p = .024), and known-groups validity using the SMT scores among people with MCI and AD (χ2 = 35.194, df = 2, p < .001) were also indicative of the instrument's good validity. Data analysis also revealed acceptable levels of face validity (U = 4.50; p = .095) and content validity (CVR ≥ 0.60). As a result of comparing VSWM and wayfinding variables across genders and education levels, a significant difference was observed for navigation and orientation and spatial anxiety between women and men (p < .05). None of the variables were different among education levels. CONCLUSION: The SMT was found to be a reliable and valid tool for measuring VSWM performance in older adults. Given these findings, the SMT can be regarded as a measure that sufficiently approximates both laboratory and real-life demands for VSWM. Additionally, the instrument demonstrated a preliminary acceptable capacity to differentiate between healthy individuals and those with MCI and AD.

Development and content validity of the cognition in daily life scale (CDL).

Cognitive impairment can negatively influence daily functioning. Current cognitive measures are essential for diagnosing cognitive impairment, but findings on these tests do not always represent the level of cognitive functioning in daily life. Therefore, this study aimed to design a structured measurement instrument to observe and rate the impact of cognitive impairment in daily life, named the cognition in daily life scale for persons with cognitive problems (CDL). In this paper we describe the development, expected usability, and psychometric properties (content and face validity) of the instrument. The CDL was established through three consecutive development phases: (1) item selection, (2) item categorization and comparison, and (3) item revision and manual construction. Subsequently, a panel of eleven international experts rated the relevance of the selected items and provided comments on the expected usability and face validity. Content validity was estimated with the content validity index, based on which four items were removed. The experts' comments led to minor adjustments of the manual, domains, and formulation of the maintained items. The final instrument consists of 65 items describing behaviour that relies on cognitive functions within six domains. Future research should focus on evaluating the construct validity and reliability of the CDL.

Synchronization of Neurophysiological and Biomechanical Data in a Real-Time Virtual Gait Analysis System (GRAIL): A Proof-of-Principle Study.

The investigation of gait and its neuronal correlates under more ecologically valid conditions as well as real-time feedback visualization is becoming increasingly important in neuro-motor rehabilitation research. The Gait Real-time Analysis Interactive Lab (GRAIL) offers advanced opportunities for gait and gait-related research by creating more naturalistic yet controlled environments through immersive virtual reality. Investigating the neuronal aspects of gait requires parallel recording of brain activity, such as through mobile electroencephalography (EEG) and/or mobile functional near-infrared spectroscopy (fNIRS), which must be synchronized with the kinetic and /or kinematic data recorded while walking. This proof-of-concept study outlines the required setup by use of the lab streaming layer (LSL) ecosystem for real-time, simultaneous data collection of two independently operating multi-channel EEG and fNIRS measurement devices and gait kinetics. In this context, a customized approach using a photodiode to synchronize the systems is described. This study demonstrates the achievable temporal accuracy of synchronous data acquisition of neurophysiological and kinematic and kinetic data collection in the GRAIL. By using event-related cerebral hemodynamic activity and visually evoked potentials during a start-to-go task and a checkerboard test, we were able to confirm that our measurement system can replicate known physiological phenomena with latencies in the millisecond range and relate neurophysiological and kinetic data to each other with sufficient accuracy.

Reliability of Xsens IMU-Based Lower Extremity Joint Angles during In-Field Running.

The Xsens Link motion capture suit has become a popular tool in investigating 3D running kinematics based on wearable inertial measurement units outside of the laboratory. In this study, we investigated the reliability of Xsens-based lower extremity joint angles during unconstrained running on stable (asphalt) and unstable (woodchip) surfaces within and between five different testing days in a group of 17 recreational runners (8 female, 9 male). Specifically, we determined the within-day and between-day intraclass correlation coefficients (ICCs) and minimal detectable changes (MDCs) with respect to discrete ankle, knee, and hip joint angles. When comparing runs within the same day, the investigated Xsens-based joint angles generally showed good to excellent reliability (median ICCs > 0.9). Between-day reliability was generally lower than the within-day estimates: Initial hip, knee, and ankle angles in the sagittal plane showed good reliability (median ICCs > 0.88), while ankle and hip angles in the frontal plane showed only poor to moderate reliability (median ICCs 0.38-0.83). The results were largely unaffected by the surface. In conclusion, within-day adaptations in lower-extremity running kinematics can be captured with the Xsens Link system. Our data on between-day reliability suggest caution when trying to capture longitudinal adaptations, specifically for ankle and hip joint angles in the frontal plane.

Test conditions impact measures of visual, perceptual, and cognitive performance.

Traditionally, visual, perceptual, and cognitive (VPC) testing is performed in well-lit, silent rooms, whilst seated, and with little incentive. Whilst this is a well-controlled setting, it may lack key features of ecological validity and therefore generalisations to real-world environments and tasks may be erroneous. In the present study, 60 participants completed tests of processing speed, divided attention, and selective attention under varying conditions of light, auditory demands, movement demands, and incentive. The results found that processing speed was significantly better in the incentive condition compared to the non-incentive condition; and in the seated and standing conditions compared to the stepping condition. Divided attention and selective attention were significantly worse in the silent condition compared to the music conditions. No significant differences were found between light and dark conditions. These findings demonstrate that performance on the VPC tests is affected by auditory conditions, movement conditions, and incentives, but not light conditions.

It is important that test conditions reflect the real-world environment of interest (e.g. driving or sports), yet often this is not the case. This study demonstrated that the visual, perceptual, and cognitive test scores of individuals vary dependent on the auditory, movement, and incentive conditions of the environment.

Clinical practices in Swedish speech-language pathology for children with (developmental) language disorder.

In Sweden, treatment for children with (developmental) language disorder ((D)LD) is traditionally carried out at a speech-language pathology (SLP) clinic, and based on formal language tests, which may not entirely represent the child's everyday language and communication skills. SLP services that include video recordings have shown positive outcomes in terms of providing information about children's linguistic and communicative abilities in everyday life, but little is known about the use of video in clinical practice. The aim of this study is therefore to investigate how Swedish SLPs link their clinical practices (assessment, treatment, and evaluation of treatment outcome) to the everyday language and communication abilities of children with (D)LD. A further aim is to explore SLPs' utilisation of video recordings as a part of their clinical practices with the target group. A web-based questionnaire was distributed to SLPs in Sweden, who work with children with (D)LD. Results demonstrate that Swedish SLPs perceive that their intervention is in alignment with children's everyday language and communication needs to a fairly high degree. However, an exception is assessment, which is considered to have a weaker alignment with children's everyday communication abilities. The use of video recordings for clinical purposes is very limited. It is suggested here that incorporating video recordings from children's everyday life would be an easy and time-efficient way to strengthen the ecological validity of SLP practices for children with (D)LD.

Do infants understand educational television content based on scientific findings?

Although attempts to create evidence-based television content for infants from birth to 2 years of age are notable, it has not been empirically verified to what extent infants understand such content. Our study evaluated whether Japanese 11- to 20-month-olds (N = 97; 52 boys and 45 girls) understand evidence-based television content using a looking-time method. When presented with content based on number themes, infants demonstrated an understanding of addition. When presented with content related to moral cognition, infants preferentially looked at a helper more than at a non-helper. Results reveal that infants understand educational television content based on scientific findings, demonstrating robustness and ecological validity. We discuss the possibility that broadcasting such content promotes infants' sensitivity to numbers and morals and provides learning opportunities through television.

Prospective memories in the wild: Predicting memory for intentions in natural environments.

Prospective memory, the ability to remember an intention at the appropriate future moment, is often investigated in the laboratory to maximize experimental control. However, demands of laboratory prospective memory tasks only partly map onto everyday demands. Therefore, it is an open question whether factors which predict prospective memory in the laboratory also predict prospective memory in the real world. We combined diary and ecological momentary assessment methods to investigate which factors, that have been repeatedly shown to predict prospective memory performance in laboratory tasks, are related to the fulfillment of everyday intentions. Results showed that substantial portions of variance in real-world prospective memory performance could be explained with the factors found to be significant in laboratory. The most powerful predictors were perceived intention importance, the use of external memory aids, delay interval, and conscientiousness. However, some meaningful laboratory predictors (e.g., working memory) played only a minor role in natural environments and a large portion of the variance in everyday intention fulfillment remained unexplained. The results substantially extend the understanding of conditions and personality variables most conducive to remembering intentions, but they also suggest that additional factors influencing real-world prospective memory remain to be discovered.

Fall history in older adults impacts acceleration profiles after a near collision with a moving pedestrian hazard.

BACKGROUND: Environmental hazards (e.g., pedestrian traffic) cause falls and testing environment impacts gait in older adults. However, most fall risk evaluations do not assess real-world moving hazard avoidance. AIMS: This study examined the effect of fall history in older adults on acceleration profiles before, during, and after a near collision with a moving hazard, in laboratory and real-world settings. METHODS: Older adults with (n = 14) and without a fall history (n = 15) performed a collision avoidance walking task with a sudden moving hazard in real-world and laboratory settings. Gait acceleration and video data of participants' first-person views were recorded. Four mixed effects multilevel models analyzed the magnitude and variability of mean and peak anteroposterior and mediolateral acceleration while walking before, during, and after the moving hazard in both environments. RESULTS: In the real-world environment, older adults without a fall history increased their mean anteroposterior acceleration after the moving hazard (p = 0.046), but those with a fall history did not (p > 0.05). Older adults without a fall history exhibited more intersubject variability than those with a fall history in mean (p < 0.001) and peak anteroposterior (p = 0.015) acceleration across environments and epochs. Older adults without a fall history exhibited a slower peak mediolateral reaction during the moving hazard (p = 0.014) than those with a fall history. CONCLUSIONS: These results suggest that compared to older adults with a fall history, older adults without a fall history are more adaptable and able to respond last-minute to unexpected hazards. Older adults with a fall history exhibited more homogenous responses.

An ecologically valid examination of event-based and time-based prospective memory using immersive virtual reality: The influence of attention, memory, and executive function processes on real-world prospective memory.

Studies on prospective memory (PM) predominantly assess either event- or time-based PM by implementing non-ecological laboratory-based tasks. The results deriving from these paradigms have provided findings that are discrepant with ecologically valid research paradigms that converge on the complexity and cognitive demands of everyday tasks. The Virtual Reality Everyday Assessment Lab (VR-EAL), an immersive virtual reality (VR) neuropsychological battery with enhanced ecological validity, was implemented to assess everyday event- and time-based PM, as well as the influence of other cognitive functions on everyday PM functioning. The results demonstrated the role of delayed recognition, planning, and visuospatial attention on everyday PM. Delayed recognition and planning ability were found to be central in event- and time-based PM respectively. In order of importance, delayed recognition, visuospatial attention speed, and planning ability were found to be involved in event-based PM functioning. Comparably, planning, visuospatial attention accuracy, delayed recognition, and multitasking/task-shifting ability were found to be involved in time-based PM functioning. These findings further suggest the importance of ecological validity in the study of PM, which may be achieved using immersive VR paradigms.

Validity of the Behavioural Assessment of the Dysexecutive Syndrome for Children (BADS-C) in children and adolescents with pediatric acquired brain injury.

The Behavioural Assessment of the Dysexecutive Syndrome for Children (BADS-C) was developed to address the need for a standardized ecologically valid test of executive function (EF) in the pediatric population. Our study aimed to investigate the discriminant, concurrent, and ecological validity of BADS-C in a sample with pediatric acquired brain injury (pABI). Seventy-four participants with pABI aged 10-17 years were included to a pre-registered randomized controlled trial, and baseline assessment was used for the current study. Controls consisted of 60 participants aged 10-17 years. Participants with pABI were assessed with neuropsychological tests and questionnaires of EF, and measurements of general intellectual ability (IQ). Results showed that all BADS-C subtests discriminated between participants with pABI and controls, except for the Playing Cards Test. Concurrent and ecological validity was demonstrated through associations between BADS-C total score, Key Search Test, and Zoo Map Test 1, and neuropsychological tests and teacher questionnaire ratings of EF. Key Search Test and Zoo Map Test 1 predicted teacher ratings of EF, beyond IQ and other neuropsychological test of EF. These findings provide support for BADS-C as a valid clinical assessment tool that can detect everyday executive dysfunction in the pABI population, and guide rehabilitation and treatment decisions.

Validation of a Persian version of an English language ecologically-valid assessment of executive functions through childhood and adolescence.

Childhood and adolescence are pivotal periods for cognitive development. Executive functions are crucial for efficient cognitive functioning, so accurate assessment is important. One ecologically-valid virtual reality test is the Jansari assessment of Executive Functions for Children (JEF-C©). In a cross-sectional study, we aimed at translating, adapting and validating JEF-C into Persian, and at investigating whether this Persian version (JEF-C (P)) can identify stages of development of executive functions in children aged from 8 to 16. Children and adolescents (N = 146) falling into three age groups participated: 8-10, 11-13 and 14-16 years old. They completed JEF-C (P) and the Wisconsin Card Sorting Test (WCST). There were acceptable Cronbach's alpha coefficients for JEF-C(P) total score (α = .72) and all constructs, except action-based prospective memory, had a positive impact on total internal consistency. There was an effect of age group on overall JEF-C (P) performance and of age on four constructs. There was also a correlation between the number of categories on WCST and the prioritization construct of JEF-C (P). It seems that JEF-C (P) is an ecologically valid executive function assessment sensitive to age and could be useful for both researchers and clinicians working with children.

It is not real until it feels real: Testing a new method for simulation of eyewitness experience with virtual reality technology and equipment.

Laboratory research in the psychology of witness testimony is often criticized for its lack of ecological validity, including the use of unrealistic artificial stimuli to test memory performance. The purpose of our study is to present a method that can provide an intermediary between laboratory research and field studies or naturalistic experiments that are difficult to control and administer. It uses Video-360° technology and virtual reality (VR) equipment, which cuts subjects off from external stimuli and gives them control over the visual field. This can potentially increase the realism of the eyewitness's experience. To test the method, we conducted an experiment comparing the immersion effect, emotional response, and memory performance between subjects who watched a video presenting a mock crime on a head-mounted display (VR goggles; n = 57) and a screen (n = 50). The results suggest that, compared to those who watched the video on a screen, the VR group had a deeper sense of immersion, that is, of being part of the scene presented. At the same time, they were not distracted or cognitively overloaded by the more complex virtual environment, and remembered just as much detail about the crime as those viewing it on the screen. Additionally, we noted significant differences between subjects in ratings of emotions felt during the video. This may suggest that the two formats evoke different types of discrete emotions. Overall, the results confirm the usefulness of the proposed method in witness research.

Learning about threat from friends and strangers is equally effective: An fMRI study on observational fear conditioning.

Humans often benefit from social cues when learning about the world. For instance, learning about threats from others can save the individual from dangerous first-hand experiences. Familiarity is believed to increase the effectiveness of social learning, but it is not clear whether it plays a role in learning about threats. Using functional magnetic resonance imaging, we undertook a naturalistic approach and investigated whether there was a difference between observational fear learning from friends and strangers. Participants (observers) witnessed either their friends or strangers (demonstrators) receiving aversive (shock) stimuli paired with colored squares (observational learning stage). Subsequently, participants watched the same squares, but without receiving any shocks (direct-expression stage). We observed a similar pattern of brain activity in both groups of observers. Regions related to threat responses (amygdala, anterior insula, anterior cingulate cortex) and social perception (fusiform gyrus, posterior superior temporal sulcus) were activated during the observational phase, possibly reflecting the emotional contagion process. The anterior insula and anterior cingulate cortex were also activated during the subsequent stage, indicating the expression of learned threat. Because there were no differences between participants observing friends and strangers, we argue that social threat learning is independent of the level of familiarity with the demonstrator.