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Background:Prior work examining emotional dysregulation observed in posttraumatic stress disorder (PTSD) has primarily been limited to fear-learning processes specific to anticipation, habituation, and extinction of threat. In contrast, the response to threat itself has not been systematically evaluated.Objective:To explore potential disruption in fear conditioning neurocircuitry in service members with PTSD, specifically in response to predictableversusunpredictable threats.Method:In the current study, active-duty U.S. Army soldiers with (PTSD group;n= 38) and without PTSD (deployment-exposed controls; DEC;n= 40), participated in a fear-conditioning study in which threat predictability was manipulated by presenting an aversive unconditioned stimulus (UCS) that was either preceded by a conditioned stimulus (i.e., predictable) or UCS alone (i.e., unpredictable). Threat expectation, skin conductance response (SCR), and functional magnetic resonance imaging (fMRI) signal to predictable and unpredictable threats (i.e., UCS) were assessed.Results:Both groups showed greater threat expectancy and diminished threat-elicited SCRs to predictable compared to unpredictable threat. Significant group differences were observed within the amygdala, hippocampus, insula, and superior and middle temporal gyri. Contrary to our predictions, the PTSD group showed a diminished threat-related response within each of these brain regions during predictable compared to unpredictable threat, whereas the DEC group showed increased activation.Conclusion:Although, the PTSD group showed greater threat-related diminution, hypersensitivity to unpredictable threat cannot be ruled out. Furthermore, pre-trauma, trait-like factors may have contributed to group differences in activation of the neurocircuitry underpinning fear conditioning.

Rhesus monkeys and humans perform more accurately in matching-to-sample tasks when the sample stimulus moves through space (Washburn et al., 1989; Washburn, 1993). This Stimulus Movement Effect (SME) is believed to be due to movement increasing attention toward the sample stimulus, creating an easier discrimination between the sample and choice stimuli. To date, there is no evidence for this phenomenon in a non-mammalian species. In the current study, we investigate the possibility of an SME in an avian species. Across three experiments, pigeons were tested with moving and stationary sample stimuli in a non-matching- to-sample task. The area and velocity by which the sample stimulus traveled was manipulated but no advantage for moving over stationary sample trials was found within or across sessions. Even when a delay condition was implemented, there was no advantage for moving sample trials. Contrary to the results found in humans and monkeys, pigeons performed better when the sample was stationary, a negative SME, and no evidence was found that stimulus movement increases discrimination performance.

relational concepts depend upon relationships between stimuli (e.g., same vs. different) and transcend features of the training stimuli. Recent evidence shows that learning abstract concepts is shared across a variety species including birds. Our recent work with a highly-skilled food-storing bird, Clark's nutcracker, revealed superior same/different abstract-concept learning compared to rhesus monkeys, capuchin monkeys, and pigeons. Here we test a more social, but less reliant on food-storing, corvid species, the Black-billed magpie (Pica hudsonia). We used the same procedures and training exemplars (eight pairs of the same rule, and 56 pairs of the different rule) as were used to test the other species. Magpies (n = 10) showed a level of abstract-concept learning that was equivalent to nutcrackers and greater than the primates and pigeons tested with these same exemplars. These findings suggest that superior initial abstract-concept learning abilities may be shared across corvids generally, rather than confined to those strongly reliant on spatial memory.

Background: There is a significant number of military personnel with a history of mild traumatic brain injury (mTBI) who suffer from comorbid posttraumatic stress symptoms (PTS). Although there is evidence of disruptions of the default mode network (DMN) associated with PTS and mTBI, previous studies have only studied static connectivity while ignoring temporal variability of connectivity. Objective: To assess DMN disrupted or dysregulated neurocircuitry, cognitive functioning, and psychological health of active-duty military with mTBI and PTS. Method: U.S. Army soldiers with PTS (n = 14), mTBI + PTS (n = 25), and healthy controls (n = 21) voluntarily completed a cognitive and symptom battery. In addition, participants had magnetic resonance imaging (MRI) to assess both static functional connectivity (SFC) and variance of dynamic functional connectivity (vDFC) of the DMN. Results: Both the PTS and mTBI + PTS groups had significant symptoms, but only the comorbid group had significant decrements in cognitive functioning. Both groups showed less stable and disrupted neural signatures of the DMN, mainly constituting the cingulate-frontal-temporal-parietal attention network. Specifically, the PTS group showed a combination of both reduced contralateral strength and reduced unilateral variability of frontal- cingulate- temporal connectivities, as well as increased variability of frontal- parietal connectivities. The mTBI + PTS group had fewer abnormal connectives than the PTS group, all of which included reduced strength of frontal- temporal regions and reduced variability frontal- cingulate- temporal regions. Greater SFC and vDFC connectivity of the left dorsolateral prefrontal cortex (dlPFC) ↔ precuneus was associated with higher cognitive scores and lower symptom scores. Conclusions: Findings suggest that individuals with PTS and mTBI + PTS have a propensity for accentuated generation of thoughts, feelings, sensations, and/or images while in a resting state. Compared with controls, only the PTS group was associated with accentuated variability of the frontal- parietal attention network. While there were no significant differences in DMN connectivity strength between the mTBI + PTS and PTS groups, variability of connectivity was able to distinguish them.

Background and objectives Emotionally relevant pictorial stimuli utilized in studies to characterize both normal and pathological emotional responses do not include military scenarios. Failures to replicate consistent findings for military populations have led to speculation that these image sets do not capture personally relevant experiences. Methods The Military Affective Picture System (MAPS) was developed consisting of 240 images depicting scenes common among military populations. A Self-Assessment Manikin was administered to a 1) U.S. Army soldiers and a 2) non-military population. Results Findings revealed gender differences in valence and dominance dimensions, but not arousal, for both samples. Valence scores were higher for the military. Arousal ratings decrease as a product of combat exposure. Civilian females demonstrated stronger correlations of valence and arousal when viewing positive or negative images. Limitations Given the limited power achieved in the current studies' gender comparisons; it would be difficult to draw major conclusions regarding the interaction of combat exposure or military status with gender for each of the categories. Without having included the IAPS ratings for comparison it is difficult to conclude whether effects only pertain to viewing MAPS images, or if there was unintentional selection bias. Additional ratings would provide better assessments for these effects in both males and females. Conclusions The MAPS has potential as a screening instrument and clinical evaluation tool for assessing treatment outcomes for individuals with combat-related psychopathology. The MAPS is freely available for research to non-profit groups upon request at http://www.cla.auburn.edu/psychology/military-affective-picture-system/ .

Same/Different abstract-concept learning by Clark's nutcrackers (Nucifraga columbiana) was tested with novel stimuli following learning of training set expansion (8, 16, 32, 64, 128, 256, 512, and 1024 picture items). The resulting set-size function was compared to those from rhesus monkeys (Macaca mulatta), capuchin monkeys (Cebus apella), and pigeons (Columba livia). Nutcrackers showed partial concept learning following initial eight-item set learning, unlike the other species (Magnotti, Katz, Wright, & Kelly, 2015). The mean function for the nutcrackers' novel-stimulus transfer increased linearly as a function of the logarithm of training set size, which intersected its baseline function at the 128-item set size. Thus, nutcrackers on average achieved full concept learning (i.e., transfer statistically equivalent to baseline performance) somewhere between set sizes of 64 to 128 items, similar to full concept learning by monkeys. Pigeons required a somewhat larger training set (256 items) for full concept learning, but results from other experiments (initial training and transfer with 32- and 64-item set sizes) suggested carryover effects with smaller set sizes may have artificially prolonged the pigeon's full concept learning. We find it remarkable that these diverse species with very different neural architectures can fully learn this same/different abstract concept, and (at least under some conditions) do so with roughly similar sets sizes (64-128 items) and numbers of training exemplars, despite initial concept learning advantages (nutcrackers), learning disadvantages (pigeons), or increasing baselines (monkeys).

Much of what we assume about the functional topography of the hippocampus was derived from a single case study over half a century ago. Given advances in the imaging sciences, a new era of discovery is underway, with potential to transform our understanding of healthy processing as well as our ability to treat disorders. We employed coactivation based parcellation, a meta-analytic approach, and ultra-high field, high-resolution functional and structural neuroimaging to characterize the neurofunctional topography of the hippocampus. Data revealed strong support for an evolutionarily preserved topography along the long-axis. Specifically, the left hippocampus was segmented into three distinct clusters: an emotional processing cluster supported by structural and functional connectivity to the amygdala and parahippocampal gyrus, a cognitive operations cluster, with functional connectivity to the anterior cingulate and inferior frontal gyrus, and a posterior perceptual cluster with distinct structural connectivity patterns to the occipital lobe coupled with functional connectivity to the precuneus and angular gyrus. The right hippocampal segmentation was more ambiguous, with plausible 2- and 5-cluster solutions plausible. Segmentations shared connectivity with brain regions known to support the correlated processes. This represents the first neurofunctional topographic model of the hippocampus using a robust, bias-free, multi-modal approach.

Chapter Overview The computational technology known as big data and its subsequent processing, analytics, are driving innovation in electric power system integration of renewable energy, outage prediction, processing of increasing volumes of smart grid data, and velocity of such data. In the age of cybersecurity, the veracity of these data is also a factor. The almost concurrent rise of cognitive computing gives new importance to unstructured data such as images and text, and the intelligent connection of real-time numerical data with written and visual data gives rise to even more innovation. The benefits of high-precision weather modeling on power demand, grid damage, and solar- and wind-based generation are also considered.

Many species have demonstrated the capacity to learn abstract concepts. Recent studies have shown that the quantity of stimuli used during training plays a critical role in how subjects learn abstract concepts. As the number of stimuli available in the training set increases, so too does performance on novel combinations. The role of set size has been explored with learning the concept of matching and same/different but not with learning the concept of difference. In the present study, pigeons were trained in a non-matching-to-sample task with an initial training set of three stimuli followed by transfer tests to novel stimuli. The training set was progressively doubled eight times with learning and transfer following each expansion. Transfer performance increased from chance level (50 %) at the smallest set size to a level equivalent to asymptotic training performance at the two largest training set sizes (384, 768). This progressive novel-stimulus transfer function of a non-matching (difference) rule is discussed in comparison with results from a similar experiment where pigeons were trained on a matching rule.

Historically, much of what we know about human memory has been discovered in experiments using visual and verbal stimuli. In two experiments, participants demonstrated reliably high recognition for nonverbal liquids. In Experiment 1, participants showed high accuracy for recognizing tastes (bitter, salty, sour, sweet) over a 30-s delay in a recognition task, even when the probe stimulus was only a different concentration within the same taste. In Experiment 2, participants tasted three liquids and showed both primacy and recency effects in a serial-position recognition task with varying delay lengths (15, 30, 45, 60 s). Recognition for liquids at the end of a list was most evident with shorter delay lengths (i.e., recency). Recognition for liquids at the start of the list was most evident with longer delay lengths (i.e., primacy). These data show that not only is gustatory information stored and maintained in working memory, but that memory for these liquids follow a recency-to-primacy shift in recognition memory. (PsycINFO Database Record

Dogs are increasingly utilized for specialized scent detection tasks. Methods for accurately identifying suitable candidates are lacking, as evidenced by the high rate of dogs failing to be placed in service. Given that behavioral factors have the greatest influence on working dog success, developing better methods for their identification is critical. The aim of this study was to use the ‘Unsolvable Task’ to measure persistence and social behavior in a population of candidate detection dogs (n = 81) to determine ontogenetic effects and potential relationships to detection dog success. Both human- and task-oriented behaviors were assessed in candidates of 3, 6, and 11 months of age. We found that human-directed gazing during the Unsolvable Task was nearly absent in puppies 6 months or younger and increased significantly at 11 months (p

Objectives Military service members risk acquiring posttraumatic stress disorder (PTSD) and mild-traumatic brain injury (mTBI), with high comorbidity. Owing to overlapping symptomatology in chronic mTBI or postconcussion syndrome (PCS) and PTSD, it is difficult to assess the etiology of a patient's condition without objective measures. Using resting-state functional MRI in a novel framework, we tested the hypothesis that their neural signatures are characterized by functionally hyperconnected brain regions which are less variable over time. Additionally, we predicted that such connectivities possessed the highest ability in predicting the diagnostic membership of a novel subject (top-predictors) in addition to being statistically significant. Methods U.S. Army Soldiers (N = 87) with PTSD and comorbid PCS + PTSD were recruited along with combat controls. Static and dynamic functional connectivities were evaluated. Group differences were obtained in accordance with our hypothesis. Machine learning classification (MLC) was employed to determine top predictors. Results From whole-brain connectivity, we identified the hippocampus-striatum connectivity to be significantly altered in accordance with our hypothesis. Diffusion tractography revealed compromised white-matter integrity between aforementioned regions only in the PCS + PTSD group, suggesting a structural etiology for the PCS + PTSD group rather than being an extreme subset of PTSD. Employing MLC, connectivities provided worst-case accuracy of 84% (9% more than psychological measures). Additionally, the hippocampus-striatum connectivities were found to be top predictors and thus a potential biomarker of PTSD/mTBI. Conclusions PTSD/mTBI are associated with hippocampal-striatal hyperconnectivity from which it is difficult to disengage, leading to a habit-like response toward episodic traumatic memories, which fits well with behavioral manifestations of combat-related PTSD/mTBI. Hum Brain Mapp 38:2843-2864, 2017. © 2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Brain connectivity studies report group differences in pairwise connection strengths. While informative, such results are difficult to interpret since our understanding of the brain relies on region‐based properties, rather than on connection information. Given that large disruptions in the brain are often caused by a few pivotal sources, we propose a novel framework to identify the sources of functional disruption from effective connectivity networks. Our approach integrates static and time‐varying effective connectivity modeling in a probabilistic framework, to identify aberrant foci and the corresponding aberrant connectomics network. Using resting‐state fMRI, we illustrate the utility of this novel approach in U.S. Army soldiers (N = 87) with posttraumatic stress disorder (PTSD), mild traumatic brain injury (mTBI) and combat controls. Additionally, we employed machine‐learning classification to identify those significant connectivity features that possessed high predictive ability. We identified three disrupted foci (middle frontal gyrus [MFG], insula, hippocampus), and an aberrant prefrontal‐subcortical‐parietal network of information flow. We found the MFG to be the pivotal focus of network disruption, with aberrant strength and temporal‐variability of effective connectivity to the insula, amygdala and hippocampus. These connectivities also possessed high predictive ability (giving a classification accuracy of 81%); and they exhibited significant associations with symptom severity and neurocognitive functioning. In summary, dysregulation originating in the MFG caused elevated and temporally less‐variable connectivity in subcortical regions, followed by a similar effect on parietal memory‐related regions. This mechanism likely contributes to the reduced control over traumatic memories leading to re‐experiencing, hyperarousal and flashbacks observed in soldiers with PTSD and mTBI. Hum Brain Mapp 39:264–287, 2018. © 2017 Wiley Periodicals, Inc.

Corvids (birds of the family Corvidae) display intelligent behavior previously ascribed only to primates, but such feats are not directly comparable across species. To make direct species comparisons, we used a same/different task in the laboratory to assess abstract-concept learning in black-billed magpies ( Pica hudsonia). Concept learning was tested with novel pictures after training. Concept learning improved with training-set size, and test accuracy eventually matched training accuracy—full concept learning—with a 128-picture set; this magpie performance was equivalent to that of Clark’s nutcrackers (a species of corvid) and monkeys (rhesus, capuchin) and better than that of pigeons. Even with an initial 8-item picture set, both corvid species showed partial concept learning, outperforming both monkeys and pigeons. Similar corvid performance refutes the hypothesis that nutcrackers’ prolific cache-location memory accounts for their superior concept learning, because magpies rely less on caching. That corvids with “primitive” neural architectures evolved to equal primates in full concept learning and even to outperform them on the initial 8-item picture test is a testament to the shared (convergent) survival importance of abstract-concept learning.

Scarcity of an offering biases consumer decision making. Most existing scarcity effect research has relied on self-reports, whereas the scarcity-based urgency often makes it difficult for consumers to explain their own decisions. This study employs a neural experiment to collect brain activity and neural network metrics from functional magnetic resonance imaging (fMRI) scans of 12 consumers' brains at the moment of their purchase decision making upon exposure to 102 promotional stimuli with varying scarcity conditions. Findings reveal that scarcity enhanced activities at self-related brain regions, supporting the role of scarcity in elevating symbolic value information processing. When subjects decided to purchase, brain regions related to emotion (e.g., amygdala) were more active; whereas when they decided not to purchase a scarce product, brain regions involved in controlled processing were more active. This study unraveled the neural underpinnings of the scarcity effect on consumers' cognitive and emotional decision making.

We examined the role of the hippocampus in list-memory processing. Three rhesus monkeys that had extensive experience in this task and had demonstrated full abstract-concept learning and excellent list memory performance (Katz et al., 2002; Wright et al., 2003) received bilateral neurotoxic hippocampal lesions and were re-tested in the serial list memory task. Effects of delays on memory performance were measured in all monkeys, whereas the effects of proactive interference were assessed in only one. Despite a slight change in performance of one of the three animals during re-learning of the same/different task, selective hippocampal damage had little or no effects on list memory accuracy. In addition, the hippocampal damage did not impact serial list position functions (SPFs) but slightly altered the dynamic of the SPF curves. Finally, even more remarkable was that accurate memory performance of one animal remained intact despite the use of small set size of 8 items that created high proactive interference across lists thereby eliminating any use of familiarity judgments to support performance. Together the findings indicate that, with short list items and extensive training in the task (i.e., reference memory), monkeys with selective hippocampal lesions may be able to use alternative memory processes (i.e., working memory) that are mediated by structures other than the hippocampus.

Diffusion tensor imaging (DTI) provides us an insight into the micro-architecture of white-matter tracts in the brain. This method has proved promising in understanding and investigating the neuronal tracts and structural connectivity between the brain regions in primates as well as rodents. The close evolutionary relationship between canines and humans may have spawned a unique bond in regard to social cognition rendering them useful as an animal model in translational research. In this study, we acquired diffusion data from anaesthetized dogs and created a DTI-based atlas for a canine model which could be used to investigate various white matter diseases. We illustrate the application of this atlas by calculating DTI tractography based structural connectivity between the anterior cingulate cortex (ACC) and posterior cingulate cortex (PCC) regions of the default mode network (DMN) in dogs. White matter connectivity was investigated to provide structural basis for the functional dissociation observed between the anterior and posterior parts of DMN. A comparison of the integrity of long range structural connections (such as in the DMN) between dogs and humans is likely to provide us with new perspectives on the neural basis of the evolution of cognitive functions.

Scarcity accelerates decision makers' perceived perishability of an offer, limiting their freedom to delay the purchase decision and creating a sense of urgency for an immediate action. Despite the ubiquity of scarcity tactics in marketing, empirical explanations of the integrative psychological mechanism underlying the scarcity effect have been scant. This study examines consumers' affective, cognitive, and conative responses to scarce offerings. Through an online experiment with 203 college consumers, this study revealed that the scarcity effects on consumers' affective response (arousal) and conative response (buying intent) were relatively robust across multiple products, suggesting the strong role of scarcity in leading to consumers' emotional decision making. However, scarcity effects on consumers' cognitive responses regarding the product benefit dimensions differed across products. Further research is needed to delve into the personal or situational factors that lead to differential scarcity effects on consumers' cognitive information processing of product benefits.

Previous work in discrimination learning has shown that nonmatching (oddity) tasks are learned faster and more accurately than comparable matching tasks. This learning advantage has been coined the oddity preference effect (Wright & Delius in Journal of Experimental Psychology: Animal Behavior Processes, 31, 425-432. doi: 10.1037/0097-7403.31.4.425 , 2005). Pigeons trained in a nonmatching task, following training in a same/different (S/D) task, learned the abstract concept of difference (Daniel et al., in Animal Cognition, 18(4), 831-837, 2015), but they did not show the expected faster acquisition or high levels of transfer from the oddity preference effect. In the present study, experimentally naive pigeons were trained in an identical nonmatching task to examine whether they would show the oddity preference effect on abstract-concept learning. These experimentally naive pigeons did show an oddity preference effect; their transfer to novel configurations was above chance with the initial (smallest) set size (3-item set) and was substantially more accurate than novel transfer in similar match-to-sample (MTS) or S/D tasks (Bodily et al., in Journal of Experimental Psychology: Animal Behavior Processes, 34, 178-184. doi: 10.1037/0097-7403.34.1.178 , 2008; Katz & Wright in Journal of Experimental Psychology: Animal Behavior Processes, 32, 80-86. doi: 10.1037/0097-7403.32.1.80 , 2006). As the number exemplars in the training set increased, transfer to novel configurations increased and reached equivalence to trained-stimulus performance with a 24-item set. Despite this transfer being equal to baseline performance with a 24-item set, subsequent transfers following training with larger set sizes declined before eventually rising again to baseline performance. This unusual set-size function (with inflection points at the 24- and 96-set sizes) suggests that these pigeons may have combined item-specific and relational learning strategies with differing emphasis as they acquired the abstract concept.

Bray et al. (2017, Proceedings of the National Academy of Sciences, 113(32), 9128–9133) recently showed that maternal interactions between service dog mothers and their puppies were predictive of puppies’ future success as a candidate service dog. These findings prompt questions into the role of genetics and early experiences and may provide useful selection tools for working dog breeding programs.

Processes of proactive interference were explored using the pigeon as a model system of memory. This study shows that proactive interference extends back in time at least 16 trials (and as many minutes), revealing a continuum of interference and providing a framework for studying memory. Pigeons were tested in a delayed same/different task containing trial-unique pictures. On interference trials, sample pictures from previous trials reappeared as test pictures on different trials. Proactive-interference functions showed greatest interference from the most recent trial and with the longer of two delays (10 s vs. 1 s). These interference functions are accounted for by a time-estimation model based on signal detection theory. The model predicts that accuracy at test is determined solely by the ratio of the elapsed time since the offset of the current-trial sample to the elapsed time since the offset of the interfering sample. Implications for comparing memory of different species and different types of memory (e.g., familiarity vs. recollection) are discussed.

Pigeons were trained in a new procedure to test for visual binding errors between the dimensions of color and shape. In Experiment 1, pigeons learned to discriminate a target compound from 15 non-target compounds (constructed from four colors and shapes) by choosing one of two hoppers in a two-hopper choice task. The similarity of the target to non-target stimuli influenced choice responding. In Experiment 2, pigeons learned to detect a target compound when presented with a non-target compound within the same trial under conditions of simultaneity and sequentiality. Non-target trials were arranged to allow for the testing of binding errors (i.e., false identifications of the target on certain non-target trials). Transient evidence for binding errors in two of the birds occurred at the start of two-item training, but decreased with training. The experiments represent an important step toward developing a framework for the evaluation of visual feature binding in nonhumans.

Six pigeons were trained in a change detection task with four colors. They were shown two colored circles on a sample array, followed by a test array with the color of one circle changed. The pigeons learned to choose the changed color and transferred their performance to four unfamiliar colors, suggesting that they had learned a generalized concept of color change. They also transferred performance to test delays several times their 50-msec training delay without prior delay training. The accurate delay performance of several seconds suggests that their change detection was memory based, as opposed to a perceptual attentional capture process. These experiments are the first to show that an animal species (pigeons, in this case) can learn a change detection task identical to ones used to test human memory, thereby providing the possibility of directly comparing short-term memory processing across species.

The domain for relational learning was manipulated by varying the training set size for pigeons that had learned the same/different (S/D) concept. Six pigeons that had learned a S/D task with pairs of pictures with a set size of 1024 picture items had their training set size reduced to 8 items. Training on the reduced 8-item set was followed by transfer testing that was repeated four times. Transfer performance following reduction of the training set to 8 items was 9.2% less than it had been when the pigeons were trained with the 1024-item set, but 25.8% above chance. This partial abstract-concept learning remained constant over the four tests with novel stimuli. The results show that a broad domain established by a large expanding training set can once again become restricted by further training with a small training set.

Monkeys and pigeons learned a same/different task with pairs that were selected from a training set of eight picture stimuli. They showed no novel-stimulus transfer and hence no abstract-concept learning. They were also tested with novel pairs of the eight training pictures (i.e., combinations that had not been used in training) and with inverted pictures of the training pairs. If the subjects had learned the task item-specifically (e.g., if-then or configural learning), they should have failed these tests, but they performed well with novel combinations of training pictures and inverted pictures, suggesting that they learned the task relationally (i.e., on the basis of the relationship between the two pictures that were presented in each trial). This somewhat paradoxical conclusion of relational learning in the absence of abstract-concept learning is contrary to most theories of abstract-concept learning. The implications of this conclusion are discussed in the context of restricted-domain relational learning.

Three pigeons were trained in a three-item simultaneous same/different task. Three of six stimulus combinations were not trained (untrained set) and were tested later. Following acquisition, the subjects were tested with novel stimuli, the untrained set, training-stimulus inversions, and object shape and color manipulations. There was no novel-stimulus transfer--that is, no abstract-concept learning. Two pigeons showed partial transfer to untrained pairs and good transfer to stimulus inversions, suggesting that they had learned the relationship between the stimuli. Lack of transfer by the third pigeon suggests item-specific learning. The somewhat surprising finding of relational learning by 2 pigeons with only six training pairs suggests restricted-domain relational learning that was controlled more by color than by shape features. Individual differences of item-specific learning by 1 pigeon and relational learning by 2 others demonstrate that this task can be learned in different ways and that relational learning can occur in the absence of novel-stimulus transfer.

An interactive 3D desktop virtual environment task was created to investigate learning mechanisms in human problem solving. Participants were assessed for previous video game experience, divided into two groups (Training and Control), and matched for gender and experience. The Training group learned specific skills within the virtual environment before being presented a problem. The Control group was presented the problem only. Completion time was faster for the Training group and was affected by level of previous video game experience. Results indicated problem solving was a function of specific and general experience and demonstrated a method for dissociating these two facets of experience.

In an open-field search task, pigeons (Columba livia) were trained to search for a goal located at the midpoint of the hypothetical line connecting two discrete visual landmarks positioned 60 cm apart. In Experiment 1, global orienting cues were absent. After reaching training criteria, pigeons were tested with novel interlandmark distances. Search location and error on test trials suggested pigeons learned relative distance. In Experiment 2, a global orienting cue was present. After reaching training criteria, pigeons were again tested with novel interlandmark distances. Results suggested pigeons learned relative and absolute distances. In Experiment 3, pigeons searched at the midpoint of rotated arrays in both the presence and absence of an orienting cue indicating learning of relative direction. In Experiment 4, pigeons searched in the appropriate goal direction when presented with a single landmark in the presence of the orienting cue but not in its absence indicating learning of absolute direction. Results implicate a stable frame of reference as critical to spatial coding strategies and suggest pigeons are able to code location based on absolute and relative distance and direction from discrete visual landmarks.

Among long-standing issues in animal cognition is which (nonhuman) animal species have the cognitive ability to learn abstract concepts (e.g., Premack, 1978). The hallmark of abstract concepts is that they transcend specific features of the training stimuli because they are based upon relationships (i.e., relational learning). In a seminal paper that was instrumental in the modern resurgence of animal cognition, David Premack said “…unlike the primate, the behavior of the pigeon is predominantly controlled by absolute rather than relational factors…” (1978, p. 432). Premack’s claim that item-specific learning (i.e., absolute factors) by pigeons has been the accepted explanation for why pigeons, at that time, had failed to learn abstract concepts (e.g., Cumming, Berryman, & Cohen, 1965; Farthing & Opuda, 1974; Santi 1978). Nevertheless, evidence began to emerge that if a large number of training stimuli (e.g., 152 color cartoons) were used, pigeons actually could learn a matching-to-sample (MTS) abstract concept (Wright, Cook, Rivera, Sands, & Delius, 1988). A somewhat more advantageous procedure than MTS for testing abstract-concept learning is the same/different procedure because the matching and non-matching stimuli are presented on separate trials. Details of currently used S/D procedures used to test pigeon abstract-concept learning vary widely including the numbers of stimuli used in training and testing (e.g., Blaisdell & Cook, 2005; Cook, Kelly, & Katz, 2003; Santiago & Wright, 1984; Wasserman, Hugart, & Kirkpatrick-Steger, 1995; Young & Wasserman, 1997). In consideration of the evidence that some species only accurately transfer their performance to novel stimuli following training with a substantial number of training stimuli, we have regularly made the number of training stimuli a parameter in our experiments. In a series of experiments with rhesus monkeys, capuchin monkeys, and pigeons, we began training with a small set of 8 stimuli and then progressively expanded (doubled) the training set followed by transfer tests with novel stimuli (Katz & Wright, 2006; Katz, Wright, & Bachevalier, 2002; Wright, Rivera, Katz, & Bachevalier, 2003). This regime allowed us to assess whether or not the degree of concept learning would depend on the number of training exemplars and whether or not transfer would eventually reach the level of baseline performance with the training stimuli. We anticipated that large numbers of training stimuli might be necessary to achieve a level of transfer equivalent to baseline performance, and therefore used picture stimuli. We selected pictures so that the training and testing pictures would be distinctive from one another and the transfer stimuli were only tested once, by definition of their being novel. In these experiments when the training set was expanded sufficiently (256 items for pigeons, 128 for monkeys), transfer became equivalent to baseline performance which remained above 80% correct. We termed this full abstract-concept learning because the baseline performance sets an upper limit. This result was the first time that pigeons had shown full concept learning in an S/D task, but pigeons required more training exemplars (i.e., stimulus pairs of same or different) than rhesus or capuchin monkeys. We characterized this species difference as a quantitative difference in contrast to the ability to fully learn the S/D abstract concept which we characterized as a qualitative similarity. The purpose of the experiments of this article was to explore whether or not training pigeons with somewhat larger initial sets of stimuli might produce better transfer than those trained initially with an 8-item set in the prior study. Training with the smaller 8-item set might produce carryover effects that would interfere with generalized relational learning which would in turn be necessary for good performance with the large training sets. To this end, we trained different groups of pigeons with larger initial training sets and compared their transfer to groups trained initially with smaller training sets. Such comparisons, of course, would depend upon pigeons being able to learn the S/D task with large training sets. With these considerations, the first group of pigeons was trained on an intermediate set size of 32 pictures.

Visual change detection mirrors conscious attention. In the flicker task, pairs of scenes are presented rapidly; the second scene differs from the first, and the participant identifies the change. Change occurs in either a central-interest region or marginal-interest region of the scene. Detecting change in a marginal-interest region requires that attention be disengaged from the central-interest region. In two flicker experiments the dependent variable was the number of scene-pair repetitions before the change was identified. The independent variables were snake-fearful versus snake-tolerant participants, presence versus absence of a snake in the scene, and a change within a central-interest versus marginal-interest region. Snake-fearful participants took longer than snake-tolerant participants to identify changes in scenes without a snake. The explanation is offered that snake-fearful participants took longer than snake-tolerant participants to disengage attention from scenes in which a snake was present; delayed disengagement from scenes that included a snake impeded the detection of change in scenes that did not.

Pigeons learned a matching-to-sample task with a split training-set design in which half of the stimulus displays were untrained and tested following acquisition. Transfer to the untrained displays along with no novel-stimulus transfer indicated that these pigeons learned the task (partially) via if-then rules. Comparisons to other performance measures indicated that they also partially learned the task via configural learning (learning the gestalt of the whole stimulus display). Differences in the FR-sample requirement (1 vs. 20) had no systematic effect on the type of learning or level of learning obtained. Differences from a previous study [Wright, A.A., 1997. Concept learning and learning strategies. Psychol. Sci. 8, 119-123] are discussed, including the effect of displaying the stimuli vertically (traditional display orientation) or horizontally from the floor.

concepts--rules that transcend training stimuli--have been argued to be unique to some species. Pigeons, a focus of much concept-learning research, were tested for learning a matching-to-sample abstract concept. Five pigeons were trained with three cartoon stimuli. Pigeons pecked a sample 10 times and then chose which of two simultaneously presented comparison stimuli matched the sample. After acquisition, abstract-concept learning was tested by presenting novel cartoons on 12 out of 96 trials for 4 consecutive sessions. A cycle of doubling the training set followed by retraining and novel-testing was repeated eight times, increasing the set size from 3 to 768 items. Transfer performance improved from chance (i.e., no abstract-concept learning) to a level equivalent to baseline performance (>80%) and was similar to an equivalent function for same/different abstract-concept learning. Analyses assessed the possibility that item-specific choice strategies accounted for acquisition and transfer performance. These analyses converged to rule out item-specific strategies at all but the smallest set-sizes (3-24 items). Ruling out these possibilities adds to the evidence that pigeons learned the relational abstract concept of matching-to-sample.

Background One of the barriers to studying the behavioral and emotional effects of pain using functional Magnetic Resonance Imaging (fMRI) is the absence of a commercially available, MRI-compatible, pressure-based algometer to elicit pain. The present study sought to address this barrier through creation and validation of a novel MRI-safe apparatus capable of delivering incremental, measurable amounts of pressure inside a scanning bore. New method We introduced an MR-safe device used to administer pressure-based pain. To test against a commercially available, MRI-incompatible algometer (AlgoMed), 199 participants reported their pain tolerance for both devices. A second experiment tested the validity of pressure-based pain in an MRI environment by comparing brain activation with established neural networks for pain. 10 participants performed an identical procedure to test for pain tolerance while being scanned in a 7T MRI scanner. Results Results support the validity and reliability of our novel device. In Study 1, pain tolerance with this device was strongly correlated with pain tolerance as measured by a commercially available algometer (r = 0.78). In Study 2, this device yielded BOLD activation within the insula (BA 13) and anterior cingulate gyrus (BA 24); as pressure increased, activation in these areas parametrically increased. Comparison with existing method These findings correspond to other studies using thermal, electrical, or mechanical pain applications. Behavioral and functional data demonstrate that this new device is a valid method of administering pressure-related pain in MRI environments. Conclusions Our novel MRI-safe device is a valid instrument to measure and administer pressure-based pain.

The generalization hypothesis of abstract-concept learning was tested with a meta-analysis of rhesus monkeys (Macaca mulatta), capuchin monkeys (Cebus apella), and pigeons (Columba livia) learning a same/different (S/D) task with expanding training sets. The generalization hypothesis states that as the number of training items increases, generalization from the training pairs will increase and could explain the subjects' accurate novel-stimulus transfer. By contrast, concept learning is learning the relationship between each pair of items; with more training items subjects learn more exemplars of the rule and transfer better. Having to learn the stimulus pairs (the generalization hypothesis) would require more training as the set size increases, whereas learning the concept might require less training because subjects would be learning an abstract rule. The results strongly support concept or rule learning despite severely relaxing the generalization-hypothesis parameters. Thus, generalization was not a factor in the transfer from these experiments, adding to the evidence that these subjects were learning the S/D abstract concept.

Same/Different abstract-concept learning by Clark's nutcrackers (Nucifraga columbiana) was tested with novel stimuli following learning of training set expansion (8, 16, 32, 64, 128, 256, 512, and 1024 picture items). The resulting set-size function was compared to those from rhesus monkeys (Macaca mulatta), capuchin monkeys (Cebus apella), and pigeons (Columba livia). Nutcrackers showed partial concept learning following initial eight-item set learning, unlike the other species (Magnotti, Katz, Wright,Kelly, 2015). The mean function for the nutcrackers' novel-stimulus transfer increased linearly as a function of the logarithm of training set size, which intersected its baseline function at the 128-item set size. Thus, nutcrackers on average achieved full concept learning (i.e., transfer statistically equivalent to baseline performance) somewhere between set sizes of 64 to 128 items, similar to full concept learning by monkeys. Pigeons required a somewhat larger training set (256 items) for full concept learning, but results from other experiments (initial training and transfer with 32- and 64-item set sizes) suggested carryover effects with smaller set sizes may have artificially prolonged the pigeon's full concept learning. We find it remarkable that these diverse species with very different neural architectures can fully learn this same/different abstract concept, and (at least under some conditions) do so with roughly similar sets sizes (64-128 items) and numbers of training exemplars, despite initial concept learning advantages (nutcrackers), learning disadvantages (pigeons), or increasing baselines (monkeys).

The current study examined whether pigeons could learn to use abstract concepts as the basis for conditionally switching behavior as a function of time. Using a mid-session reversal task, experienced pigeons were trained to switch from matching-to-sample (MTS) to non-matching-to-sample (NMTS) conditional discriminations within a session. One group had prior training with MTS, while the other had prior training with NMTS. Over training, stimulus set size was progressively doubled from 3 to 6 to 12 stimuli to promote abstract concept development. Prior experience had an effect on the initial learning at each of the set sizes but by the end of training there were no group differences, as both groups showed similar within-session linear matching functions. After acquiring the 12-item set, abstract-concept learning was tested by placing novel stimuli at the beginning and end of a test session. Prior matching and non-matching experience affected transfer behavior. The matching experienced group transferred to novel stimuli in both the matching and non-matching portion of the sessions using a matching rule. The non-matching experienced group transferred to novel stimuli in both portions of the session using a non-matching rule. The representations used as the basis for mid-session reversal of the conditional discrimination behaviors and subsequent transfer behavior appears to have different temporal sources. The implications for the flexibility and organization of complex behaviors are considered.

Working memory (WM), or the ability to temporarily store and manipulate information, is one of the most widely studied constructs in cognitive psychology. Since its inception, it has become one of the leading explanations for how humans are able to operate on a cognitive level. The current study probed the neural networks underlying one of the most commonly used tasks, delayed match-to-sample (DMTS), to study WM. An activation likelihood estimation (ALE) analysis of 42 functional neuroimaging studies (626 participants) was conducted to demonstrate neural network engagement during DMTS. Results demonstrated strong convergence in brain regions commonly associated with the working memory construct (i.e., dorsolateral prefrontal cortex, fusiform gyrus, and posterior parietal cortex). However, neural activation in two regions frequently attributed to WM were absent from this meta-analysis: the anterior cingulate and the rostral prefrontal cortex, suggesting that these regions may be more sensitive to task or stimuli characteristics. In a post-hoc analysis, we deconstructed the DMTS meta-analysis to examine nonverbal versus verbal stimuli, and found notable neurofunctional differences such that DMTS using nonverbal stimuli consistently engaged the right middle frontal gyrus (BA 6/46) and precuneus (BA 7) more so than verbal stimuli based DMTS. These results provide a foundation for future models of functional connectivity that may elucidate subtle differences in working memory attributable to pathological processes.

The ability to learn abstract relational concepts is fundamental to higher level cognition. In contrast to item-specific concepts (e.g. pictures containing trees versus pictures containing cars), abstract relational concepts are not bound to particular stimulus features, but instead involve the relationship between stimuli and therefore may be extrapolated to novel stimuli. Previous research investigating the same/different abstract concept has suggested that primates might be specially adapted to extract relations among items and would require fewer exemplars of a rule to learn an abstract concept than non-primate species. We assessed abstract-concept learning in an avian species, Clark's nutcracker ( Nucifraga columbiana ), using a small number of exemplars (eight pairs of the same rule, and 56 pairs of the different rule) identical to that previously used to compare rhesus monkeys, capuchin monkeys and pigeons. Nutcrackers as a group ( N = 9) showed more novel stimulus transfer than any previous species tested with this small number of exemplars. Two nutcrackers showed full concept learning and four more showed transfer considerably above chance performance, indicating partial concept learning. These results show that the Clark's nutcracker, a corvid species well known for its amazing feats of spatial memory, learns the same/different abstract concept better than any non-human species (including non-human primates) yet tested on this same task.

Mechanisms of same/different concept learning by rhesus monkeys, capuchin monkeys, and pigeons were studied in terms of how these species learned the task (e.g., item-specific learning versus relational learning) and how rapidly they learned the abstract concept, as the training set size was doubled. They had similar displays, training stimuli, test stimuli, and contingencies. The monkey species learned the abstract concept at similar rates and more rapidly than pigeons, thus showing a quantitative difference across species. All species eventually showed full concept learning (novel-stimulus transfer equivalent to baseline: 128-item set size for monkeys; 256-item set for pigeons), thus showing a qualitative similarity across species. Issues of stimulus regularity/symmetry, generalization from item pairs, and familiarity processing were not considered to be major factors in the final performances, converging on the conclusion that these species were increasingly controlled by the sample-test relationship (i.e., relational processing) leading to full abstract-concept learning.

A dynamic 3-D virtual environment was constructed for humans as an open-field analogue of Blaisdell and Cook's (2005) pigeon foraging task to determine if humans, like pigeons, were capable of integrating separate spatial maps. Participants used keyboard keys and a mouse to search for a hidden goal in a 4x4 grid of raised cups. During Phase 1 training, a goal was consistently located between two landmarks (Map 1: blue T and red L). During Phase 2 training, a goal was consistently located down and left of a single landmark (Map 2: blue T). Transfer trials were then conducted in which participants were required to make choices in the presence of the red L alone. Cup choices during transfer assessed participants' strategies: association (from Map 1), generalization (from Map 2), or integration (combining Map 1 and 2). During transfer, cup choices increased to a location which suggested an integration strategy and was consistent with results obtained with pigeons. However, additional analyses of the human data suggested participants initially used a generalization strategy followed by a progressive shift in search behavior away from the red L. This shift in search behavior during transfer was responsible for the changes in cup choices across transfer trials and was confirmed by a control condition. These new analyses offer an alternative explanation to the spatial integration account proposed for pigeons.

Background: We investigated the hypothesis that manipulation of cardiac output (CO) with esmolol (Es) or ephedrine (E) affects the onset time of rocuronium. Methods: Following anesthesia induction, 33 patients received E (70 µg kg−1), Es (500 µg kg−1) or placebo (P) 30 s before rocuronium (0.6 mg kg−1) administration. Cardiac output was measured non-invasively after intubation every 3 min. The interval from the end of rocuronium administration to the disappearance of all twitches was considered to be the onset time. Results: Onset time was shorter after E (52.2 ± 16.5 s) and longer after Es (114.3 ± 11.1 s) compared with P (87.4 ± 7.3 s) (P

Recognition of words and kaleidoscope pictures showed a double dissociation of left and right hippocampal activity using magnetic source imaging (MSI). MSI has advantages over alternative imaging techniques that measure hemodynamic changes for identifying regional changes in brain activity in real time and on an individual subject basis without the need for image subtraction. In this study, lists of words or kaleidoscope pictures were presented for memorization followed by tests of list items and foils during which brain activity was recorded. There was greater activation in the left than the right hippocampus with abstract nouns (e.g., relief) and greater activation in the right than the left hippocampus with kaleidoscope pictures. This dissociation was evident on a case by case basis. This study demonstrates the specialization of the two medial temporal lobe (MTL) regions, including the hippocampi, for mnemonic processing of verbal and pictorial items that are difficult to encode verbally.

Experiments with 9 rhesus monkeys (Macaca mulatta) showed, for the first time, that abstract-concept learning varied with the training stimulus set size. In a same/different task, monkeys required to touch a top picture before choosing a bottom picture (same) or white rectangle (different) learned rapidly. Monkeys not required to touch the top picture or presented with the top picture for a fixed time learned slowly or not at all. No abstract-concept learning occurred after 8-item training but progressively improved with larger set sizes and was complete following 128-item training. A control monkey with a constant 8-item set ruled out repeated training and testing. Contrary to the unique-species account, it is argued that different species have quantitative, not qualitative, differences in abstract-concept learning.