Associative Learning Processes Research Articles

Brain mechanisms supporting violated expectations of pain.

The subjective experience of pain is influenced by interactions between experiences, future predictions, and incoming afferent information. Expectations of high pain can exacerbate pain, whereas expectations of low pain during a consistently noxious stimulus can produce significant reductions in pain. However, the brain mechanisms associated with processing mismatches between expected and experienced pain are poorly understood, but are important for imparting salience to a sensory event to override erroneous top-down expectancy-mediated information. This investigation examined pain-related brain activation when expectations of pain were abruptly violated. After conditioning participants to cues predicting low or high pain, 10 incorrectly cued stimuli were administered across 56 stimulus trials to determine whether expectations would be less influential on pain when there is a high discordance between prestimulus cues and corresponding thermal stimulation. Incorrectly cued stimuli produced pain ratings and pain-related brain activation consistent with placebo analgesia, nocebo hyperalgesia, and violated expectations. Violated expectations of pain were associated with activation in distinct regions of the inferior parietal lobe, including the supramarginal and angular gyrus, and intraparietal sulcus, the superior parietal lobe, cerebellum, and occipital lobe. Thus, violated expectations of pain engage mechanisms supporting salience-driven sensory discrimination, working memory, and associative learning processes. By overriding the influence of expectations on pain, these brain mechanisms are likely engaged in clinical situations in which patients' unrealistic expectations of pain relief diminish the efficacy of pain treatments. Accordingly, these findings underscore the importance of maintaining realistic expectations to augment the effectiveness of pain management.

A kinematic study on (un)intentional imitation in bottlenose dolphins.

The aim of the present study was to investigate the effect of observing other’s movements on subsequent performance in bottlenose dolphins. The imitative ability of non-human animals has intrigued a number of researchers. So far, however, studies in dolphins have been confined to intentional imitation concerned with the explicit request to imitate other agents. In the absence of instruction to imitate, do dolphins (un)intentionally replicate other’s movement features? To test this, dolphins were filmed while reaching and touching a stimulus before and after observing another dolphin (i.e., model) performing the same action. All videos were reviewed and segmented in order to extract the relevant movements. A marker was inserted post hoc via software on the videos upon the anatomical landmark of interest (i.e., rostrum) and was tracked throughout the time course of the movement sequence. The movement was analyzed using an in-house software developed to perform two-dimensional (2D) post hoc kinematic analysis. The results indicate that dolphins’ kinematics is sensitive to other’s movement features. Movements performed for the “visuomotor priming” condition were characterized by a kinematic pattern similar to that performed by the observed dolphin (i.e., model). Addressing the issue of spontaneous imitation in bottlenose dolphins might allow ascertaining whether the potential or impulse to produce an imitative action is generated, not just when they intend to imitate, but whenever they watch another conspecific’s behavior. In closing, this will clarify whether motor representational capacity is a by-product of factors specific to humans or whether more general characteristics such as processes of associative learning prompted by high level of encephalization could help to explain the evolution of this ability.

Questioning short-term memory and its measurement: Why digit span measures long-term associative learning

Traditional accounts of verbal short-term memory explain differences in performance for different types of verbal material by reference to inherent characteristics of the verbal items making up memory sequences. The role of previous experience with sequences of different types is ostensibly controlled for either by deliberate exclusion or by presenting multiple trials constructed from different random permutations. We cast doubt on this general approach in a detailed analysis of the basis for the robust finding that short-term memory for digit sequences is superior to that for other sequences of verbal material. Specifically, we show across four experiments that this advantage is not due to inherent characteristics of digits as verbal items, nor are individual digits within sequences better remembered than other types of individual verbal items. Rather, the advantage for digit sequences stems from the increased frequency, compared to other verbal material, with which digits appear in random sequences in natural language, and furthermore, relatively frequent digit sequences support better short-term serial recall than less frequent ones. We also provide corpus-based computational support for the argument that performance in a short-term memory setting is a function of basic associative learning processes operating on the linguistic experience of the rememberer. The experimental and computational results raise questions not only about the role played by measurement of digit span in cognition generally, but also about the way in which long-term memory processes impact on short-term memory functioning.

Sex differences in cerebellar mechanisms involved in pain-related safety learning

Recent studies have suggested that the cerebellum contributes to the central processing of pain, including pain-related learning and memory processes. As a complex experience with multiple emotional and cognitive facets, the response to pain and its underlying neural correlates differ between men and women. However, it remains poorly understood whether and to what extent sex differences exist in the cerebellar contribution to pain-related associative learning processes. In the present conditioning study with experimental abdominal pain as unconditioned stimuli (US), we assessed sex-dependent differences in behavioral and neural responses to conditioned warning and safety cues in healthy volunteers. The results revealed that in response to visual stimuli signaling safety from abdominal pain (CS−), women showed enhanced cerebellar activation in lobules I–IV, V, VI, VIIIa, IX and X as well as Crus II and the dentate nucleus, which are mostly representative of somatomotor networks. On the other hand, men showed enhanced neural activation in lobules I–IV, VI, VIIb, VIIIb, IX as well as Crus I and II in response to CS−, which are representative of frontoparietal and ventral attention networks. No sex differences were observed in response to pain-predictive warning signals (CS+). Similarly, men and women did not differ in behavioral measures of conditioning, including conditioned changes in CS valence and contingency awareness. Together, we could demonstrate that the cerebellum is involved in associative learning processes of conditioned anticipatory safety from pain and mediates sex differences in the underlying neural processes. Given the high prevalence of chronic pain conditions in women, these results may contribute to improve our understanding of the acquisition and manifestation of chronic abdominal pain syndromes.

Cortical Synaptic Inhibition Declines during Auditory Learning.

Auditory learning is associated with an enhanced representation of acoustic cues in primary auditory cortex, and modulation of inhibitory strength is causally involved in learning. If this inhibitory plasticity is associated with task learning and improvement, its expression should emerge and persist until task proficiency is achieved. We tested this idea by measuring changes to cortical inhibitory synaptic transmission as adult gerbils progressed through the process of associative learning and perceptual improvement. Using either of two procedures, aversive or appetitive conditioning, animals were trained to detect amplitude-modulated noise and then tested daily. Following each training session, a thalamocortical brain slice was generated, and inhibitory synaptic properties were recorded from layer 2/3 pyramidal neurons. Initial associative learning was accompanied by a profound reduction in the amplitude of spontaneous IPSCs (sIPSCs). However, sIPSC amplitude returned to control levels when animals reached asymptotic behavioral performance. In contrast, paired-pulse ratios decreased in trained animals as well as in control animals that experienced unpaired conditioned and unconditioned stimuli. This latter observation suggests that inhibitory release properties are modified during behavioral conditioning, even when an association between the sound and reinforcement cannot occur. These results suggest that associative learning is accompanied by a reduction of postsynaptic inhibitory strength that persists for several days during learning and perceptual improvement.

Evolved computers with culture. Commentary: From computers to cultivation: reconceptualizing evolutionary psychology

Evolved computers with culture. Commentary: From computers to cultivation: reconceptualizing evolutionary psychology

Victimization experiences and the stabilization of victim sensitivity.

People reliably differ in the extent to which they are sensitive to being victimized by others. Importantly, “victim sensitivity” predicts how people behave in social dilemma situations: Victim-sensitive individuals are less likely to trust others and more likely to behave uncooperatively—especially in socially uncertain situations. This pattern can be explained with the sensitivity to mean intentions (SeMI) model, according to which victim sensitivity entails a specific and asymmetric sensitivity to contextual cues that are associated with untrustworthiness. Recent research is largely in line with the model’s prediction, but some issues have remained conceptually unresolved so far. For instance, it is unclear why and how victim sensitivity becomes a stable trait and which developmental and cognitive processes are involved in such stabilization. In the present article, we will discuss the psychological processes that contribute to a stabilization of victim sensitivity within persons, both across the life span (“ontogenetic stabilization”) and across social situations (“actual-genetic stabilization”). Our theoretical framework starts from the assumption that experiences of being exploited threaten a basic need, the need to trust. This need is so fundamental that experiences that threaten it receive a considerable amount of attention and trigger strong affective reactions. Associative learning processes can then explain (a) how certain contextual cues (e.g., facial expressions) become conditioned stimuli that elicit equally strong responses, (b) why these contextual untrustworthiness cues receive much more attention than, for instance, trustworthiness cues, and (c) how these cues shape spontaneous social expectations (regarding other people’s intentions). Finally, avoidance learning can explain why these cognitive processes gradually stabilize and become a trait: the trait which is referred to as victim sensitivity.

Preventing the Development of Observationally Learnt Fears in Children by Devaluing the Model’s Negative Response

Vicarious learning has become an established indirect pathway to fear acquisition. It is generally accepted that associative learning processes underlie vicarious learning; however, whether this association is a form of conditioned stimulus-unconditioned stimulus (CS-US) learning or stimulus–response (CS-CR) learning remains unclear. Traditionally, these types of learning can be dissociated in a US revaluation procedure. The current study explored the effects of post-vicarious learning US revaluation on acquired fear responses. Ninety-four children (46 males and 48 females) aged 6 to 10 years first viewed either a fear vicarious learning video or a neutral vicarious learning video followed by random allocation to one of three US revaluation conditions: inflation; deflation; or control. Inflation group children were presented with still images of the adults in the video and told that the accompanying sound and image of a very fast heart rate monitor belonged to the adult. The deflation group were shown the same images but with the sound and image of a normal heart rate. The control group received no US revaluation. Results indicated that inflating how scared the models appeared to be did not result in significant increases in children’s fear beliefs, avoidance preferences, avoidance behavior or heart rate for animals above increases caused by vicarious learning. In contrast, US devaluation resulted in significant decreases in fear beliefs and avoidance preferences. Thus, the findings provide evidence that CS-US associations underpin vicarious learning and suggest that US devaluation may be a successful method for preventing children from developing fear beliefs following a traumatic vicarious learning episode with a stimulus.

Infection Control in a Far Far Away Galaxy: New and Alternative Learning Tool from Popular Culture to Improve the Antimicrobial Stewardship.

Dear Editor, Infection control still represents one of the most important issue in clinical practice, particularly in critically-ill patients. Indeed, it has to be considered as a mandatory approach in clinical practice for all healthcare workers, nonetheless it is one of the most difficult to learn and to apply. A good and significant methodology to acquire a state of mind focused on infection control during clinical practice should start early during the training of healthcare workers and should be carefully managed, likely using all possible and available learning tools. It should also involve patients and their relatives, aiming to minimize possible infection spread. Previously case studies from popular culture have been proposed as teaching tool for medical student, but possibly also for all those individuals having relation with healthcare facilities. More recently Star Wars series has been used as learning tool to focus on pathophysiology of the lung according to one of the most important character of Star Wars series, Darth Vader. Indeed Star Wars and related imaginary world holds some other important learning suggestions to emphasize another important feature of the tragic story of this popular character, or else the infection control after severe skin burn in one of its most popular character.[1] Infection still remains a leading cause of morbidity and mortality following burns,[2] being related to poor wound healing and increased risk of scarring which may have a negative prognosis and functional impact on the patient.[2] Survival following burn improves with an early wound debridement surgery and skin replacement aiming to remove the source of wound infection and restore skin integrity with particular attention to aseptic condition.[3] Critical factors previously being correlated to increased risk of developing burn wound infection (BWI) include age, percentage of total body surface area (TBSA), presence of full-thickness burns, and presence of an inhalation injury that may contribute to tissue hypoxia reducing wound strength after healing and increasing the risk of infection.[4] Among these comorbidities, fungal infection may have an important role on prognosis if not treated with an accurate clinical approach.[5] In the specific case related to Star Wars series, Anakin Skywalker (the real name of Darth Vader before its evil change) during Star Wars Episode III, after a saber duel with his Jedi Master Obi-Wan Kenobi suffers traumatic amputations of both lower limbs and his left upper limb with burns, several wounds on the head and on the face with volcanic gas inhalation. All these events, according to reported literature data could clearly predispose to infections, with related increase in mortality.[4,6] Nevertheless, in the above mentioned episode, in a relatively few time, the protagonist is assisted with a medical capsule and shortly after the rescue, he is taken in a surgical operative room. In this aseptic environment a quickly wound debridement surgery and skin replacement is performed by medical robots and finally a whole-body suit is dressed, with possibly some healing property for the skin and lung injury from volcanic gas, with a final surgical and clinical success.[1] In the Episode IV of the movie series, 22 years later,we find Darth Vader (Anakin Skywalker) still dressing whole-body suit and most importantly still alive even if affected by chronic pulmonary disease. From a medical point of view, our villain not only may be considered an example of learning tool to underline some important aspect of acute and chronic respiratory failure,[6] but also an important model of the efficacy of anearly wound debridement surgery and skin replacement to minimize infection morbidities,with a long survival. Mainly, we think that there are two key factors in this “medical history”: The use of asterile medical capsule on the site ofthe traumatic event that could be considered as a correct aseptic approach (hand hygiene, appropriated devices use) to critically-ill patients after a traumatic event, Early surgical approach in aseptic and possibly hyperbaric chamber, to be considered as accurate and specific methodology to remove source of infection in aseptic conditions. Both these two elements strongly suggest that standard hygiene precautions and a rigorous specialist approaches are fundamental methodologies to minimize risk of the infection and to ensure good prognosis of the patients in a far far away galaxy as on the Earth. Despite it would seem controversial, the use of a such kind of approach to infection control training, may help healthcare workers to target both automatic associative learning processes and conscious decision making, in addition to ensuring good knowledge of all possible measure to prevent infections, as recently suggested.[6] In conclusion, Star Wars, as any other subjects from popular culture should be considered as a really valuable approach and an alternative as well as entertaining platform for a plenary discussion with medical students on one of the most important topic in current medical practice: Infection control.

What evolves in the evolution of social learning?

AbstractSocial learning is fundamental to social life across the animal kingdom, but we still know little about how natural selection has shaped social learning abilities on a proximate level. Sometimes, complex social learning phenomena can be entirely explained by Pavlovian processes that have little to do with the evolution of sociality. This implies that the ability to learn socially could be an exaptation, not an adaptation, to social life but not that social learning abilities have been left untouched by natural selection. I discuss new empirical evidence for associative learning in social information use, explain how natural selection might facilitate the associative learning process and discuss why such studies are changing the way that we think about social learning.

Can Experimentally Induced Positive Affect Attenuate Generalization of Fear of Movement-Related Pain?

Recent experimental data show that associative learning processes are involved not only in the acquisition but also in the spreading of pain-related fear. Clinical studies suggest involvement of positive affect in resilience against chronic pain. Surprisingly, the role of positive affect in associative learning in general, and in fear generalization in particular, has received scant attention. In a voluntary movement paradigm, in which one arm movement (reinforced conditioned stimulus [CS+]) was followed by a painful stimulus and another was not (unreinforced conditioned stimulus [CS–]), we tested generalization of fear inhibition in response to 5 novel but related generalization movements (GSs; within-subjects) after either a positive affect induction or a control exercise (Group = between-subjects) in healthy participants (N = 50). The GSs' similarity with the original CS+ movement and CS– movement varied. Fear learning was assessed via verbal ratings. Results indicated that there was an interaction between the increase in positive affect and the linear generalization gradient. Stronger increases in positive affect were associated with steeper generalization curves because of relatively lower pain–unconditioned stimulus expectancy and less fear of stimuli more similar to the CS–. There was no Group by Stimulus interaction. Results thus suggest that positive affect may enhance safety learning through promoting generalization from known safe movements to novel yet related movements. Improved safety learning may be a central mechanism underlying the association between positive affect and increased resilience against chronic pain. PerspectiveWe investigated the extent to which positive affect influences the generalization (ie, spreading) of pain-related fear inhibition in response to situations similar to the original, pain-eliciting situation. Results suggest that increasing positive affect in the acute pain stage may limit the spreading of pain-related fear, thereby potentially inhibiting transition to chronic pain conditions.

Homeostatic reinforcement learning for integrating reward collection and physiological stability.

Efficient regulation of internal homeostasis and defending it against perturbations requires adaptive behavioral strategies. However, the computational principles mediating the interaction between homeostatic and associative learning processes remain undefined. Here we use a definition of primary rewards, as outcomes fulfilling physiological needs, to build a normative theory showing how learning motivated behaviors may be modulated by internal states. Within this framework, we mathematically prove that seeking rewards is equivalent to the fundamental objective of physiological stability, defining the notion of physiological rationality of behavior. We further suggest a formal basis for temporal discounting of rewards by showing that discounting motivates animals to follow the shortest path in the space of physiological variables toward the desired setpoint. We also explain how animals learn to act predictively to preclude prospective homeostatic challenges, and several other behavioral patterns. Finally, we suggest a computational role for interaction between hypothalamus and the brain reward system.

Fear-potentiated startle during extinction is associated with white matter microstructure and functional connectivity

BackgroundExtinction of conditioned fear is an associative learning process that involves communication among the hippocampus, medial prefrontal cortex, and amygdala. Strength of connectivity between the hippocampus and the anterior cingulate cortex (ACC), and between the amygdala and ventromedial prefrontal cortex (vmPFC), may influence fear-potentiated startle (FPS) responses during extinction. Specific white matter tracts, the cingulum and uncinate fasciculus (UF), serve as primary routes of communication for these areas. Our objective was to investigate associations between FPS during extinction and cingulum and UF connectivity. MethodDiffusion tensor imaging (DTI) and probabilistic tractography analyses were used to examine cingulum and UF structural connectivity in 40 female African-Americans with psychological trauma exposure. FPS responses during fear conditioning and extinction were assessed via electromyography (EMG) of the right orbicularis oculi muscle. Secondarily, functional connectivity analyses were performed with the seed regions of interest (ROIs) used for tractography. ResultsA significant negative association between cingulum microstructure and FPS during early extinction (r = −.42, p = .01) and late extinction (r = −.36, p = .03) was observed after accounting for the effects of age, trauma exposure, and psychopathology (post-traumatic stress disorder symptoms); this pattern was similar for early extinction and functional connectivity between these regions (p < .05corrected). No significant correlations were observed between FPS and UF microstructure. ConclusionsThese data indicate that structural integrity of the cingulum is directly associated with extinction learning and appears to influence functional connectivity between these regions. Decrements in cingulum microstructure may interfere with extinction learning, thereby increasing risk for the development of pathological anxiety.

Neonatal sensitization to ethanol-induced breathing disruptions as a function of late prenatal exposure to the drug in the rat: Modulatory effects of ethanol's chemosensory cues

Preclinical and clinical studies have systematically demonstrated abrupt changes in fetal respiratory patterns when the unborn organism is exposed to the effects of maternal ethanol intoxication. In subprimates, chronic exposure to this drug during gestation and infancy results in marked alterations of the plasticity of the respiratory network. These alterations are manifested in terms of an early incapability to overcome deleterious effects of hypoxic events as well as in terms of sensitization to ethanol's depressant effects upon breathing patterns. It has also been demonstrated that near term rat fetuses process ethanol's chemosensory cues when the drug contaminates the amniotic fluid and that associative learning processes occur due to the temporal contiguity existing between these cues and different ethanol-related physiological effects. In the present study during the course of late gestation (gestational days 17–20), pregnant rats were intragastrically administered with either 0.0 or 2.0g/kg ethanol. Seven-day-old pups derived of these dams were evaluated in terms of respiration rates (breaths/min) and apneas when subjected to different experimental conditions. These conditions were defined by postnatal exposure to the drug (intragastric administrations of either 0.0, 0.5, 1.0 or 2.0g/kg ethanol), postadministration time of evaluation (5–10 or 30–35min) and olfactory context at test (no explicit ambient odor or ethanol ambient odor). The results, obtained via whole body plethysmography, indicated that brief prenatal experience with the drug sensitized the organisms to ethanol's depressant effects particularly when employing the higher ethanol doses. In turn, presence of ethanol odor at test potentiated the above mentioned respiratory alterations. Prenatal treatment with ethanol was not found to alter pharmacokinetic profiles resulting from postnatal exposure to the drug or to affect different morphometric parameters related with lung development. These results indicate that even brief exposure to the drug during late gestation is sufficient to sensitize the organism to later disruptive effects of the drug upon breathing responsiveness. These deficits are potentiated through the re-exposure to the olfactory context perceived in utero which is known to be associated with ethanol's unconditioned effects. As a function of these observations it is possible to suggest a critical role of fetal sensory and learning capabilities in terms of modulating later ethanol-related breathing disruptions.

Multisensory perception as an associative learning process.

Suppose that you are at a live jazz show. The drummer begins a solo. You see the cymbal jolt and you hear the clang. But in addition seeing the cymbal jolt and hearing the clang, you are also aware that the jolt and the clang are part of the same event. Casey O’Callaghan (forthcoming) calls this awareness “intermodal feature binding awareness.” Psychologists have long assumed that multimodal perceptions such as this one are the result of a automatic feature binding mechanism (see Pourtois et al., 2000; Vatakis and Spence, 2007; Navarra et al., 2012). I present new evidence against this. I argue that there is no automatic feature binding mechanism that couples features like the jolt and the clang together. Instead, when you experience the jolt and the clang as part of the same event, this is the result of an associative learning process. The cymbal’s jolt and the clang are best understood as a single learned perceptual unit, rather than as automatically bound. I outline the specific learning process in perception called “unitization,” whereby we come to “chunk” the world into multimodal units. Unitization has never before been applied to multimodal cases. Yet I argue that this learning process can do the same work that intermodal binding would do, and that this issue has important philosophical implications. Specifically, whether we take multimodal cases to involve a binding mechanism or an associative process will have impact on philosophical issues from Molyneux’s question to the question of how active or passive we consider perception to be.

Learning pain-related fear: Neural mechanisms mediating rapid differential conditioning, extinction and reinstatement processes in human visceral pain

Background and aimsThere exists converging evidence to support a role of pain-related fear in the pathophysiology and treatment of chronic pain conditions. Pain-related fear is shaped by associative learning and memory processes, which remain poorly characterized especially in the context of abdominal pain such as in irritable bowel syndrome (IBS). Therefore, using event-related functional magnetic resonance imaging (fMRI), we assessed the neural mechanisms mediating the formation, extinction and reinstatement of abdominal pain-related fear in healthy humans. Employing painful rectal distensions as clinically-relevant unconditioned stimuli (US), in this fear conditioning study we tested if differential excitatory and inhibitory learning is evocable after very few CS–US learning trials (“rapid conditioning”), and explored the underlying neural substrates of these learning and memory processes. MethodsIn N=24 healthy men and women, “rapid” fear acquisition was accomplished by pairing visual conditioned stimuli (CS+) with painful rectal distensions as unconditioned stimuli (US), while different visual stimuli (CS−) were presented without US (differential delay conditioning with five CS+ and five CS− presentations and a 80% reinforcement ratio). During extinction, all CS were presented without US. Subsequently, a reinstatement procedure was implemented, defined as the retrieval of an extinguished memory after unexpected and unpaired exposure to the US, followed by CS presentations. For each phase, changes in perceived CS–US contingency and CS unpleasantness were assessed with visual analogue scales and compared with analyses of variance. fMRI data were analyzed using whole-brain analyses (at p<.001 uncorrected) and in regions-of-interest analyses with familywise error correction of alpha (pFWE<.05). Differential neural activation in response to the CS during each experimental phase (i.e., CS+>CS−; CS+<CS−) was analyzed without and subsequently also with a linear parametric modulation including trial number as a regressor. ResultsA significant valence change (i.e. increased CS+ unpleasantness) was observed following acquisition, indicating successful differential aversive learning. On the other hand, CS–US contingency awareness was not fully established. These behavioral results were paralleled by differential activation of the putamen (pFWE<.05), insula (pFWE<.05) and secondary somatosensory cortex (S2, p<.001 uncorrected) in response to the CS+ during acquisition. The same analysis with a linear parametric modulation confirmed but also strengthened the resulting activations, which were all highly significant in ROI analyses at pFWE<.05. Extinction and reinstatement involved differential activation in response to the CS−, involving the cingulate cortex and primary motor cortex (M1) during extinction and the posterior cingulate cortex (PCC) during reinstatement (all p<.001 uncorrected), without obvious effects upon linear parametric modulation analysis. ConclusionsAbdominal pain stimuli are effective US that elicit conditioned pain-related fear even after very few learning experiences without full contingency awareness. These findings extend similar evidence of “rapid learning” in response to interoceptive US (e.g., conditioned taste aversion, conditioned nausea), and have implications for the pathophysiology and treatment of chronic abdominal pain such as in IBS.

Strategy selection in cue-based decision making.

People can make use of a range of heuristic and rational, compensatory strategies to perform a multiple-cue judgment task. It has been proposed that people are sensitive to the amount of cognitive effort required to employ decision strategies. Experiment 1 employed a dual-task methodology to investigate whether participants' preference for heuristic versus compensatory decision strategies can be altered by increasing the cognitive demands of the task. As indicated by participants' decision times, a secondary task interfered more with the performance of a heuristic than compensatory decision strategy but did not affect the proportions of participants using either type of strategy. A stimulus set effect suggested that the conjunction of cue salience and cue validity might play a determining role in strategy selection. The results of Experiment 2 indicated that when a perceptually salient cue was also the most valid, the majority of participants preferred a single-cue heuristic strategy. Overall, the results contradict the view that heuristics are more likely to be adopted when a task is made more cognitively demanding. It is argued that people employ 2 learning processes during training, one an associative learning process in which cue-outcome associations are developed by sampling multiple cues, and another that involves the sequential examination of single cues to serve as a basis for a single-cue heuristic.

Innovative problem solving in birds: a key role of motor diversity

Foraging innovations are increasingly viewed as a key source of phenotypic plasticity and evolutionary change. Often thought to be associated with increased cognitive abilities, innovative foraging behaviour could potentially emerge as a simple consequence of being able to use a greater variety of motor actions in the foraging context. Here, we explored the role of motor diversity in the innovative problem-solving abilities of a highly successful ecological invader, the Indian myna, Sturnus tristis, using an extractive foraging task with multiple compartments. Consistent with findings from several other species, persistence predicted the latency to solve the first compartment. However, motor diversity was the strongest predictor of both solving latency of all further compartments and number of compartments solved. We suggest that motor diversity may facilitate innovation by increasing the ways in which objects can be handled, which in turn would allow for associative learning processes to enhance the expression of successful foraging behaviours.

A Much-needed Boost to EFL Learners’ Vocabulary; The Role of Associative Learning

Nobody can deny the crucial role of vocabulary in learning a language. It is through words that all four language learning skills can be presented. But if vocabulary is so important, how can it be learned? Which techniques can be employed to enlarge vocabulary? Are all of them advantageous to EFL classes? Different experts as well as textbook designers have suggested different techniques. One of them is the associative learning process. The present study is an attempt to discover the relationship between this kind of learning and enlarging Iranian EFL learners’ vocabulary. This study was conducted on both female and male fourth-graders at high schools in Mahmoud-abad, Mazandaran. The cluster sampling was applied to select the subjects and 100 students were chosen based on the average grade from the Diploma Final English Examination in Khordad 1389 (June-July 2010). They took part in a general English placement test and 60 students were chosen according to their performance. All the students in the experimental and control groups participated in a vocabulary pre-test as well. Both the subjects in the EG and CG received 12 sessions of vocabulary learning, while the experimental group went through associative learning with an emphasis on contiguity, similarity and contrast. Both groups took part in the post-test of the study. Then, the difference between the obtained means of the experimental and control groups was calculated through a t-test. Data analyses showed that the significant difference between the performances of the two groups was related to the impact of associative learning.

Associative learning alone is insufficient for the evolution and maintenance of the human mirror neuron system.

Cook et al. argue that mirror neurons originate from associative learning processes, without evolutionary influence from social-cognitive mechanisms. We disagree with this claim and present arguments based upon cross-species comparisons, EEG findings, and developmental neuroscience that the evolution of mirror neurons is most likely driven simultaneously and interactively by evolutionarily adaptive psychological mechanisms and lower-level biological mechanisms that support them.