Two Separate Brain Networks for Predicting Trainability and Tracking Training-Related Plasticity in Working Dogs.

Functional brain connectivity based on resting-state functional magnetic resonance imaging (fMRI) has been shown to be correlated with human personality and behavior. In this study, we sought to know whether capabilities and traits in dogs can be predicted from their resting-state connectivity, as in humans. We trained awake dogs to keep their head still inside a 3T MRI scanner while resting-state fMRI data was acquired. Canine behavior was characterized by an integrated behavioral score capturing their hunting, retrieving, and environmental soundness. Functional scans and behavioral measures were acquired at three different time points across detector dog training. The first time point (TP1) was prior to the dogs entering formal working detector dog training. The second time point (TP2) was soon after formal detector dog training. The third time point (TP3) was three months' post detector dog training while the dogs were engaged in a program of maintenance training for detection work. We hypothesized that the correlation between resting-state FC in the dog brain and behavior measures would significantly change during their detection training process (from TP1 to TP2) and would maintain for the subsequent several months of detection work (from TP2 to TP3). To further study the resting-state FC features that can predict the success of training, dogs at TP1 were divided into a successful group and a non-successful group. We observed a core brain network which showed relatively stable (with respect to time) patterns of interaction that were significantly stronger in successful detector dogs compared to failures and whose connectivity strength at the first time point predicted whether a given dog was eventually successful in becoming a detector dog. A second ontologically based flexible peripheral network was observed whose changes in connectivity strength with detection training tracked corresponding changes in behavior over the training program. Comparing dog and human brains, the functional connectivity between the brain stem and the frontal cortex in dogs corresponded to that between the locus coeruleus and left middle frontal gyrus in humans, suggestive of a shared mechanism for learning and retrieval of odors. Overall, the findings point toward the influence of phylogeny and ontogeny in dogs producing two dissociable functional neural networks.

A preliminary analysis of the effect of individual differences on cognitive performance in young companion dogs.

Many factors influence cognitive performance in dogs, including breed, temperament, rearing history, and training. Studies in working dog populations have demonstrated age-related improvements in cognitive task performance across the first years of development. However, the effect of certain factors, such as age, sex, and temperament, on cognitive performance in puppies has yet to be evaluated in a more diverse population of companion dogs. In this study, companion dogs under 12 months of age were tested once on two tasks purported to measure aspects of executive function: the delayed-search task (DST) and the detour reversal task (DRT). Owners also filled out the Canine Behavioral Assessment and Research Questionnaire (C-BARQ) to evaluate how temperament influenced task performance. Contrary to prior research, performance did not improve with age on either task. However, the lack of age effects was likely the result of small sample sizes and individual differences across other factors influencing performance. Specifically, temperament differences as measured by the C-BARQ subscales for nonsocial fear and excitability predicted task performance on the DST, but the effect of temperament on task performance differed between males and females. Excitability also predicted performance on the DRT, but the effect depended on the age of the dog. In addition, no correlations were observed between task measures, indicating a lack of construct validity. Overall, these findings provide a preliminary analysis of factors that appear to influence cognitive task performance in young companion dogs and highlight suggestions for future research evaluating the impact of individual differences on cognitive performance.

Effects of proactive interference on olfactory memory in dogs.

Proactive interference (PI) occurs when memories of past events or stimuli intrude in the present moment, causing working memory (WM) errors. These errors are often measured through WM tests such as matching-to-sample (MTS). When the repetition of individual stimuli increases, there is a greater chance of these intrusions, and thus there can be a decrease in accuracy in such tasks. In two experiments, we explored the nature of PI on dog working memory. First, we manipulated the size of the set of odors (2, 6, trial-unique) used to construct each session to maximize (2-odor set) and minimize (trial-unique) within-session proactive interference during an olfactory MTS task. Matching-to-sample accuracy decreased with greater PI. Second, we adapted procedures originally designed for pigeons and rhesus macaques to determine the locus of PI in dogs. To test for proactive interference, probe trials were inserted into MTS sessions where sample odors from earlier trials reappeared as incorrect comparisons. Incorrect responses on these probe trials indicated proactive interference. These probe tests were conducted with a 0-s or 20-s retention interval in separate sessions. We found that dogs performed worse on the matching task when the source of interference (odor stimulus) was from the immediately preceding trial compared with when they were from trials further back in the session but only for the 0-s retention interval. These results are compared with previous work examining the effects of proactive interference on working memory in other species.

The Adverse Health Outcomes, Economic Burden, and Public Health Implications of Unmanaged Attention Deficit Hyperactivity Disorder (ADHD): A Call to Action Resulting from CHADD Summit, Washington, DC, October 17, 2019.

Recent research has increasingly documented the adverse effects of ADHD on physical health in addition to its well-known effects on emotional health. Responding to this concern, CHADD organized a summit meeting of health care providers, governmental and other health-related organizations, and health care payers. A White Paper generated from the meeting reviewed the adverse health outcomes, economic burden and public health implications of unmanaged ADHD. Here we summarize the resulting Calls to Action to the various stakeholder groups including: increased awareness and education of providers; development of professional guidelines for diagnosis and treatment; insurance coverage of the relevant services; support of research targeting the role of ADHD in the etiology and treatment of physical illness; and public education campaigns.

Controlling for dogs' (Canis familiaris) use of nonmnemonic strategies in a spatial working memory task.

Short assessments of spatial working memory (SWM) in dogs are becoming popular evaluations of canine aging and individual differences. In a typical SWM task, an experimenter hides a reward inside of a bucket at a specific stimulus position while the dog watches. Then, following a varying delay interval, the dog is released to choose a bucket. The longest delay at which the dog can successfully choose the bucket containing the reward is considered to reflect the dog's SWM duration. Although past studies were informative, the tasks often lacked a valid measure of SWM due to dogs' ability to use nonmnemonic strategies, such as body orientation or sustained attention, to successfully solve these tasks without relying on working memory mechanisms. Therefore, we designed the first study to assess the internal validity of these tasks by directly comparing dogs' performance on two experimental conditions. We found that dogs performed worse in a control condition in which nonmnemonic strategies were eliminated compared with a typical SWM task condition. In addition, our results indicate a strong relationship between the percentage of delay time that a dog spends orienting its head or body to the correct bucket and performance in a typical SWM task. These findings were the first to show a difference in SWM performance when dogs' use of nonmnemonic strategies was controlled and stress the importance of considering the internal validity of these tasks if used to examine SWM in future work. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Observational drawing in the brain: A longitudinal exploratory fMRI study.

Observational drawing involves acquiring a number of basic drawing techniques and concepts. There is limited knowledge on how observational drawing skills are represented by brain responses. Here, we investigate the behavioral and functional changes behind students learning to draw in a longitudinal study on 45 participants by testing art students (n = 26) at the beginning and end of a 16-week observational drawing course compared to a matched group of non-art students (n = 19). Four novel tasks were used that involve making decisions about light sources, tonal value, line variation and linear perspective using task-based 7 T-functional Magnetic Resonance Imaging (fMRI). While exploratory in nature, we expected to find improvement on each task over time and functional changes in the prefrontal cortex and cerebellum for the art students. Art students' performance significantly improved on the light sources, line variation, and linear perspective tasks and functional changes were found for the line variation, linear perspective, and tonal value tasks. Using whole brain analyses diffuse functional changes were discovered including prefrontal cortex areas and cerebellum. Brain areas involved in cognitive processing, including attention, decision making, motor control, top-down control, visual information processing, and working memory all functionally changed with experience. These findings demonstrate some of the first functional changes in the brain due to training in the arts and have implications for pedagogy and mental health.

Abstract-concept learning in two species of new world corvids, pinyon jays (Gymnorhinus Cyanocephalus) and California scrub jays (Aphelocoma Californica).

concepts require individuals to identify relationships between novel stimuli. Previous studies have reported that the ability to learn abstract concepts is found in a wide range of species. In regard to a same/different concept, Clark's nutcrackers (Nucifraga columbiana) and black-billed magpies (Pica hudsonia), two corvid species, were shown to outperform other avian and primate species (Wright et al., 2017). Two additional corvid species, pinyon jays (Gymnorhinus cyanocephalus) and California scrub jays (Aphelocoma californica) chosen as they belong to a different clade than nutcrackers and magpies, were examined using the same set-size expansion procedure of the same/different task (the task used with nutcrackers and magpies) to evaluate whether this trait is common across the Corvidae lineage. During this task, concept learning is assessed with novel images after training. Results from the current study showed that when presented with novel stimuli after training with an 8-image set, discrimination accuracy did not differ significantly from chance for pinyon jays and California scrub jays, unlike the magpies and nutcrackers from previous studies that showed partial transfer at that stage. However, concept learning improved with each set-size expansion, and the jays reached full concept learning with a 128-image set. This performance is similar to the other corvids and monkeys tested, all of which outperform pigeons. Results from the current study show a qualitative similarity in full abstract-concept learning in all species tested with a quantitative difference in the set-size functions, highlighting the shared survival importance of mechanisms supporting abstract-concept learning for corvids and primates. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Dissociating the effects of delay and interference on dog (Canis familiaris) working memory.

Delayed matching-to-sample (dMTS) is commonly used to study working memory (WM) processes in non-humans. Previous procedures for studying dog WM, including versions of the dMTS, did not separate the impact of delay and interference on memory performance. These studies were also limited to auditory and spatial stimuli, neglecting dogs' dominant sensory modality (i.e., olfaction). Therefore, we designed the first olfactory dMTS in dogs, with systematically varied delays and number of odors in a session, to dissociate the effects of delay and within-session proactive interference on dog WM. Dogs (n = 5) initially trained on matching-to-sample with 48 odors, with a zero-second delay, were tested on four delay lengths (0, 30, 60, and 90 s), counterbalanced across three, trial-unique, sessions. Although there was a slight decrease in accuracy across delays, dogs performed above chance on delays up to 60 s, suggesting a WM duration of at least 60 s. To explore the effect of within-session proactive interference on WM duration, the size of the stimulus set was reduced to six and two odors. There was no effect on the memory function with six odors compared to the trial-unique sessions. However, the interference caused by the two-odor set was enough to decrease accuracy at each delay length. These findings suggest that forgetting in dog working memory for odors can be simultaneously influenced by delay and within-session proactive interference.

Same/different concept learning by primates and birds.

Same/different abstract-concept learning experiments were conducted with two primate species and three avian species by progressively increasing the size of the training stimulus set of distinctly different pictures from eight to 1,024 pictures. These same/different learning experiments were trained with two pictures presented simultaneously. Transfer tests of same and different learning employed interspersed trials of novel pictures to assess the level of correct performance on the very first time of subjects had seen those pictures. All of the species eventually performed these tests with high accuracy, contradicting the long-accepted notion that nonhuman animals are unable to learn the concept of same/different. Capuchin and rhesus monkeys learned the concept more readily than did pigeons. Clark's nutcrackers and black-billed magpies learned as readily as monkeys, and even showed a slight advantage with the smallest training stimulus sets. Those tests of same/different learning were followed by delay procedures, such that a delay was introduced after the subjects responded to the sample picture and before the test picture. In the sequential same/different task, accuracy was shown to diminish when the stimulus on a previous trial matched the test picture previously shown on a different trial. This effect is known as proactive interference. The pigeons' proactive interference was greater at 10-s delays than 1-s delays, revealing time-based interference. By contrast, time delays had little or no effect on rhesus monkeys' proactive interference, suggesting that rhesus monkeys have better explicit memory of where and when they saw the potential interfering picture, revealing better event-based memory.

Matching-to-sample abstract-concept learning by dogs (Canis familiaris).

The abstract concept of sameness forms the basis of higher-order cognitive operations, including mathematics and language. Historically believed to be unique to humans, evidence of abstract-concept learning in recent decades has been demonstrated in a range of phylogenetically diverse species, indicating that the ability to judge sameness relations is a general process resulting from convergent evolution. However, to date, no research has demonstrated evidence of such learning in any canid species. We trained domestic dogs (n = 6) on a two-choice olfactory matching-to-sample task using a training set of 48 odors in trial-unique sessions. Upon meeting an acquisition criterion (two consecutive sessions ≥ 83% correct), we assessed abstract-concept learning by testing for transfer to novel odors. Dogs matched novel odors with above-chance accuracy and exceeded baseline levels, satisfying previously proposed criteria for full abstract-concept learning. Our findings provide the first evidence of MTS concept learning in dogs, illustrating qualitative similarities with other species. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Dog-human social relationship: representation of human face familiarity and emotions in the dog brain.

This study investigated the behavioral and neural indices of detecting facial familiarity and facial emotions in human faces by dogs. Awake canine fMRI was used to evaluate dogs' neural response to pictures and videos of familiar and unfamiliar human faces, which contained positive, neutral, and negative emotional expressions. The dog-human relationship was behaviorally characterized out-of-scanner using an unsolvable task. The caudate, hippocampus, and amygdala, mainly implicated in reward, familiarity and emotion processing, respectively, were activated in dogs when viewing familiar and emotionally salient human faces. Further, the magnitude of activation in these regions correlated with the duration for which dogs showed human-oriented behavior towards a familiar (as opposed to unfamiliar) person in the unsolvable task. These findings provide a bio-behavioral basis for the underlying markers and functions of human-dog interaction as they relate to familiarity and emotion in human faces.

Dogs demonstrate memory of incidentally encoded information.

Fugazza, Pongrácz, Pogány, Lenkei, and Miklósi (Scientific Reports, 10(1), 1-8, 2020) recently showed that dogs can repeat incidentally encoded behaviors using unexpected tests. These results suggest that dogs may possess episodic-like memories for their own actions.

Human-dog relationships as a working framework for exploring human-robot attachment: a multidisciplinary review.

Robotic agents will be life-long companions of humans in the foreseeable future. To achieve such successful relationships, people will likely attribute emotions and personality, assign social competencies, and develop a long-lasting attachment to robots. However, without a clear theoretical framework-building on biological, psychological, and technological knowledge-current societal demands for establishing successful human-robot attachment (HRA) as a new form of inter-species interactions might fail. The study of evolutionarily adaptive animal behavior (i.e., ethology) suggests that human-animal behaviors can be considered as a plausible solution in designing and building models of ethorobots-including modeling the inter-species bond between domesticated animals and humans. Evidence shows that people assign emotional feelings and personality characteristics to animal species leading to cooperation and communication-crucial for designing social robots such as companion robots. Because dogs have excellent social skills with humans, current research applies human-dog relationships as a template to understand HRA. Our goal of this article is twofold. First, we overview the research on how human-dog interactions are implemented as prototypes of non-human social companions in HRA. Second, we review research about attitudes that humans have for interacting with robotic dogs based on their appearance and behavior, the implications for forming attachments, and human-animal interactions in the rising sphere of robot-assisted therapy. The rationale for this review is to provide a new perspective to facilitate future research among biologists, psychologists, and engineers-contributing to the creation of innovative research practices for studying social behaviors and its implications for society addressing HRA.

Comparing pet and detection dogs (Canis familiaris) on two aspects of social cognition.

Interspecific communication between dogs and humans enables dogs to occupy significant roles in human society, both in companion and working roles. Dogs excel at using human communicative signals in problem-solving tasks, and solicit human contact when unable to solve a problem. Dogs' sociocognitive behavior likely results from a selection for attention to humans during domestication, but is highly susceptible to environmental factors. Training for particular tasks appears to enhance dog-human communication, but effects may depend on the nature of the relationship determined by their role. Our aim was to examine two types of social cognition (responsiveness to human gestures, and human-directed communicative behavior in an unsolvable task) in pet dogs (n = 29) and detection dogs (n = 35). The groups did not differ in their ability to follow human signals, but pets were less responsive to signals given by a stranger than by their owner. Pets also exhibited more human-directed gazing in the unsolvable task, showing a bias for gazing at their owner compared with the stranger, whereas detection dogs showed greater persistence in attempting to solve the task compared with pets. Thus, different aspects of dogs' sociocognitive behavior may differentially vary as a function of selection or training for particular roles.

Structural Connectome Disruptions in Military Personnel with Mild Traumatic Brain Injury and Post-Traumatic Stress Disorder.

Mild traumatic brain injury (mTBI) and post-traumatic stress disorder (PTSD) are common in military populations and share numerous symptoms. Functional graph theory studies demonstrate altered small-world brain networks in mTBI and PTSD, but little is known about structural covariance networks or the potentially distinct topology of mTBI-PTSD comorbidity. The purpose of this study was to compare brain structural covariance networks in healthy active duty military service members (CON) to those with PTSD, mTBI, and mTBI-PTSD. Seventy-six service members (31 CON, 14 PTSD, 12 mTBI, 19 mTBI-PTSD) completed clinical questionnaires and structural magnetic resonance imaging scans. Cortical thickness-derived adjacency matrices were used to determine structural covariance network topologies. Pairwise comparisons for characteristic path length, clustering coefficient, modularity (global), closeness centrality (nodal), and local efficiency were made across a range of network densities (5-35%) using non-parametric permutation tests. All clinical groups showed greater levels of arousal, stress, anxiety, and depression compared with CON. Global network analysis revealed greater clustering and local efficiency in PTSD compared with CON, whereas nodal analysis indicated altered path lengths and closeness centrality in fronto-limbic areas with mTBI-PTSD. Global and nodal graph outcomes suggest distinct pathophysiological manifestations of mTBI, PTSD, and mTBI-PTSD in structural brain networks. Greater network segregation and nodal differences in fronto-limbic areas may be tied to emotional fluctuations.

The development of problem-solving abilities in a population of candidate detection dogs (Canis familiaris).

Both ontogenetic and phylogenetic factors have shaped dogs' cognitive capabilities, resulting in a heightened social sensitivity at the apparent cost of non-social problem-solving abilities. Research has suggested that training history and life experience can influence problem-solving abilities in dogs. However, the ontogenetic development of problem-solving abilities in dogs has been less explored. We tested a population of candidate detection dogs of various ages across the first year of development on four well-established problem-solving tasks targeting different cognitive domains (i.e., cylinder, A-not-B barrier, delayed search, and spatial transposition tasks). We examined developmental effects by comparing cognitive task performance across three age groups. Age-related improvements for all four cognitive measures indicate developmental increases in processes related to inhibitory control, attention, and spatial cognition between 3 and 12 months of age. Additionally, we found some relationships between cognitive measures and detection dog performance measures, though effects were not as robust. We discuss the results in the context of canine cognitive development and corresponding effects of phylogeny and ontogeny, as well as potential applications to working dog training and selection.

MALINI (Machine Learning in NeuroImaging): A MATLAB toolbox for aiding clinical diagnostics using resting-state fMRI data.

Resting-state functional Magnetic Resonance Imaging (rs-fMRI) has been extensively used for diagnostic classification because it does not require task compliance and is easier to pool data from multiple imaging sites, thereby increasing the sample size. A MATLAB-based toolbox called Machine Learning in NeuroImaging (MALINI) for feature extraction and disease classification is presented. The MALINI toolbox extracts functional and effective connectivity features from preprocessed rs-fMRI data and performs classification between healthy and disease groups using any of 18 popular and widely used machine learning algorithms that are based on diverse principles. A consensus classifier combining the power of multiple classifiers is also presented. The utility of the toolbox is illustrated by accompanying data consisting of resting-state functional connectivity features from healthy controls and subjects with various brain-based disorders: autism spectrum disorder from autism brain imaging data exchange (ABIDE), Alzheimer's disease and mild cognitive impairment from Alzheimer's disease neuroimaging initiative (ADNI), attention deficit hyperactivity disorder from ADHD-200, and post-traumatic stress disorder and post-concussion syndrome acquired in-house. Results of classification performed on the above datasets can be obtained from the main article titled "Supervised machine learning for diagnostic classification from large-scale neuroimaging datasets" [1]. The data was divided into homogeneous and heterogeneous splits, such that 80% could be used for training, model building and cross-validation, while the remaining 20% of the data could be used as a hold-out independent test data for replication of the classification performance, to ensure the robustness of the classifiers to population variance in image acquisition site and age of the sample.

Odor span task in dogs (Canis familiaris).

Working memory is essential for organisms to solve problems related to their survival and to adapt to changes in their environment. Researchers sought to create a non-human model of working memory that could be used to better understand its predictive value and underlying brain function. Several of these studies were conducted using the odor span task (OST) with rodents, and here, we present the first OST with domestic dogs (n = 6). The OST is an incrementing non-match-to-sample task in which dogs were presented with both a session novel (S +) and a previously encountered (S -) odor on each trial. A response to the session novel odor was always reinforced. Upon meeting training criterion on sessions with 24 trials or odors to remember, the dogs were tested on the OST with up to 72 odors to remember in the session. All dogs learned the OST and displayed accurate performance (≥ 79%) for the largest set size of 72 odors. In an analysis focused on the effect of intervening odors (i.e., the number of trials since the S - was last encountered), dogs demonstrated above-chance performance for up to eight intervening odors. The implications of these findings are discussed in the context of dog working memory for odors.

DisConICA: a Software Package for Assessing Reproducibility of Brain Networks and their Discriminability across Disorders.

There is a lack of objective biomarkers to accurately identify the underlying etiology and related pathophysiology of disparate brain-based disorders that are less distinguishable clinically. Brain networks derived from resting-state functional magnetic resonance imaging (rs-fMRI) has been a popular tool for discovering candidate biomarkers. Specifically, independent component analysis (ICA) of rs-fMRI data is a powerful multivariate technique for investigating brain networks. However, ICA-derived brain networks that are not highly reproducible within heterogeneous clinical populations may exhibit mean statistical separation between groups, yet not be sufficiently discriminative at the individual-subject level. We hypothesize that functional brain networks that are most reproducible in subjects within clinical and control groups separately, but not when the two groups are merged, may possess the ability to discriminate effectively between the groups even at the individual-subject level. In this study, we present DisConICA or "Discover Confirm Independent Component Analysis", a software package that implements the methodology in support of our hypothesis. It relies on a "discover-confirm" approach based upon the assessment of reproducibility of independent components (representing brain networks) obtained from rs-fMRI (discover phase) using the gRAICAR (generalized Ranking and Averaging Independent Component Analysis by Reproducibility) algorithm, followed by unsupervised clustering analysis of these components to evaluate their ability to discriminate between groups (confirm phase). The unique feature of our software package is its ability to seamlessly interface with other software packages such as SPM and FSL, so that all related analyses utilizing features of other software can be performed within our package, thus providing a one-stop software solution starting with raw DICOM images to the final results. We showcase our software using rs-fMRI data acquired from US Army soldiers returning from the wars in Iraq and Afghanistan who were clinically grouped into the following groups: PTSD (posttraumatic stress disorder), comorbid PCS (post-concussion syndrome) + PTSD, and matched healthy combat controls. This software package along with test data sets is available for download at https://bitbucket.org/masauburn/disconica.