Absence Of Prior Experience Research Articles

Looming stimuli reliably drive innate defensive responses in male rats, but not learned defensive responses

Survival relies on an organism's intrinsic ability to instinctively react to stimuli such as food, water, and threats, ensuring the fundamental ability to feed, drink, and avoid danger even in the absence of prior experience. These natural, unconditioned stimuli can also facilitate associative learning, where pairing them consistently with neutral cues will elicit responses to these cues. Threat conditioning, a well-explored form of associative learning, commonly employs painful electric shocks, mimicking injury, as unconditioned stimuli. It remains elusive whether actual injury or pain is necessary for effective learning, or whether the threat of harm is sufficient. Approaching predators create looming shadows and sounds, triggering strong innate defensive responses like escape and freezing. This study investigates whether visual looming stimuli can induce learned freezing or learned escape responses to a conditioned stimulus in male rats. Surprisingly, pairing a neutral tone with a looming stimulus only weakly evokes learned defensive responses, in contrast to the strong responses observed when the looming stimulus is replaced by a shock. This dissociation sheds light on the boundaries for learned defensive responses thereby impacting our comprehension of learning processes and defensive strategies.

Testing self-perception theory with agent-based simulation

Conventional wisdom is that a person's attitude towards an issue dictates their behaviour. In contrast, self-perception theory accounts for how a person forms their attitude. In the context of this paper, the theory asserts that a person can, in the absence of prior experience, establish an attitude towards cycling based on observing their own, hopefully, positive experience. The adaptive agent-based model, MATSim, allows one to test the self-perception theory. The case study in Cape Town, South Africa, demonstrates that as much as 7.8% of people introduced to cycling will experience it as positive, opening the door for adoption.

Too Many Cooks: Bayesian Inference for Coordinating Multi-Agent Collaboration.

Collaboration requires agents to coordinate their behavior on the fly, sometimes cooperating to solve a single task together and other times dividing it up into sub-tasks to work on in parallel. Underlying the human ability to collaborate is theory-of-mind (ToM), the ability to infer the hidden mental states that drive others to act. Here, we develop Bayesian Delegation, a decentralized multi-agent learning mechanism with these abilities. Bayesian Delegation enables agents to rapidly infer the hidden intentions of others by inverse planning. We test Bayesian Delegation in a suite of multi-agent Markov decision processes inspired by cooking problems. On these tasks, agents with Bayesian Delegation coordinate both their high-level plans (e.g., what sub-task they should work on) and their low-level actions (e.g., avoiding getting in each other's way). When matched with partners that act using the same algorithm, Bayesian Delegation outperforms alternatives. Bayesian Delegation is also a capable ad hoc collaborator and successfully coordinates with other agent types even in the absence of prior experience. Finally, in a behavioral experiment, we show that Bayesian Delegation makes inferences similar to human observers about the intent of others. Together, these results argue for the centrality of ToM for successful decentralized multi-agent collaboration.

On (Mis)perceptions of testing effectiveness: an empirical study

A recurring problem in software development is incorrect decision making on the techniques, methods and tools to be used. Mostly, these decisions are based on developers’ perceptions about them. A factor influencing people’s perceptions is past experience, but it is not the only one. In this research, we aim to discover how well the perceptions of the defect detection effectiveness of different techniques match their real effectiveness in the absence of prior experience. To do this, we conduct an empirical study plus a replication. During the original study, we conduct a controlled experiment with students applying two testing techniques and a code review technique. At the end of the experiment, they take a survey to find out which technique they perceive to be most effective. The results show that participants’ perceptions are wrong and that this mismatch is costly in terms of quality. In order to gain further insight into the results, we replicate the controlled experiment and extend the survey to include questions about participants’ opinions on the techniques and programs. The results of the replicated study confirm the findings of the original study and suggest that participants’ perceptions might be based not on their opinions about complexity or preferences for techniques but on how well they think that they have applied the techniques.

Determination of Ra leachability from filter materials originating from water treatment plant

NORM (Naturally Occurring Radioactive Material) waste management is a relatively new issue in Estonia. At the present moment, the largest volumes come from water treatment plants, where the Ra isotopes Ra-226 and Ra-228 accumulate in the filter material in the process of water purification. In the absence of prior experience and legislation, the best solution is considered to be the deposition of such material in landfill (Kiisk, 2016). In order to evaluate the possible leaching of Ra into the groundwater, experimental determination of Ra leachability from filter material is conducted within this study. The activity concentrations of the filter materials used in this study ranged from approximately 4700 to 22100 Bq/kg. The study is based on two standard methods, the batch test and percolation test, and has created environments which, in addition to imitation of natural rainwater (0.001M CaCl2), could also describe landfill conditions due to their high leachate concentrations. The results obtained suggest that Ra concentrations remains equally low for all solutions, ranging from 0.2 to 4 Bq/kg. Partition coefficient Kd, the parameter describing leaching, ranges mainly from 10000 to 33000 L/kg in the case of dilute solutions (0.001M CaCl2 solution, TDS of 111 mg/L and dilute artificial leachate with TDS of 809 mg/L) and stays around 3000 L/kg in the case of more concentrated solutions (artificial leachates with TDS of 5467 mg/L and 12160 mg/L).

Consumer engagement: the role of social currency in online reviews

ABSTRACTWe explore the interplay between social currency (SC) and consumer engagement on social networks. We use text analyses based on both human coding and machine learning asisted sentiment analysis on reviews collected from Facebook pages, and we show that SC has a positive effect on ratings and visitor loyalty. First, we find that attractions have varying makeup of SC as represented in the six dimensions of SC. Second, repeat visits increase SC. Third, SC positively impacts revisit intentions even in the absence of prior experience. We also find that prior experience does not appear to yield better ratings, however, it predicts revisit intentions. This study represents the first use of SC in the tourism domain. Theoretical and practical implications alongside limitations and future research are discussed.

Online evaluation of novel choices by simultaneous representation of multiple memories

Prior experience is critical for decision-making. It enables explicit representation of potential outcomes and provides training to valuation mechanisms. However, we can also make choices in the absence of prior experience by merely imagining the consequences of a new experience. Using functional magnetic resonance imaging repetition suppression in humans, we examined how neuronal representations of novel rewards can be constructed and evaluated. A likely novel experience was constructed by invoking multiple independent memories in hippocampus and medial prefrontal cortex. This construction persisted for only a short time period, during which new associations were observed between the memories for component items. Together, these findings suggest that, in the absence of direct experience, coactivation of multiple relevant memories can provide a training signal to the valuation system that allows the consequences of new experiences to be imagined and acted on.

Children’s familiarity with snack foods changes expectations about fullness

Palatability is regarded as a major determinant of children's energy intake. However, few studies have considered nonhedonic beliefs about foods. In adults, there is emerging evidence that expectations about the satiating properties of foods are an important determinant of meal size, and these beliefs are learned. We measured and quantified children's expected satiation across energy-dense snack foods by using a method of adjustment. Participants changed a comparison-food portion (pasta and tomato sauce) to match the satiation that they expected from a snack food. We predicted that children who were especially familiar with snack foods would expect the foods to generate greater satiation and that children who were unfamiliar with snack foods would match expected satiation on the basis of the physical characteristics (perceived volume) of the foods. Seventy 11- to 12-y-old children completed measures of expected satiation, perceived volume, familiarity, and liking across 6 snack foods. As anticipated, familiarity and expected satiation were positively related (r = 0.37, P = 0.002), and this association remained after liking was controlled for. Furthermore, expected-satiation and perceived-volume judgments were more dissimilar as familiarity with the foods increased. Our findings highlight the role of learning in shaping children's beliefs about the postingestive effects of the consumption of foods; children who ate the foods more often expected them to deliver greater satiation. Furthermore, our findings suggest that, in the absence of prior experience, children rely on a food's physical characteristics (a less-complex strategy) when they judge expected satiation. This trial was registered at clinicaltrials.gov as NCT01403753.

Familiarity modulates mirror neuron and mentalizing regions during intention understanding

Recent research suggests that the inference of others' intentions from their observed actions is supported by two neural systems that perform complementary roles. The human putative mirror neuron system (pMNS) is thought to support automatic motor simulations of observed actions, with increased activity for previously experienced actions, whereas the mentalizing system provides reflective, non-intuitive reasoning of others' perspectives, particularly in the absence of prior experience. In the current fMRI study, we show how motor familiarity with an action and perceptual familiarity with the race of an actor uniquely modulate these two systems. Chinese participants were asked to infer the intentions of actors performing symbolic gestures, an important form of non-verbal communication that has been shown to activate both mentalizing and mirror neuron regions. Stimuli were manipulated along two dimensions: (1) actor's race (Caucasian vs. Chinese actors) and (2) participants' level of experience with the gestures (familiar or unfamiliar). We found that observing all gestures compared to observing still images was associated with increased activity in key regions of both the pMNS and mentalizing systems. In addition, observations of one's same race generated greater activity in the posterior pMNS-related regions and the insula than observations of a different race. Surprisingly, however, familiar gestures more strongly activated regions associated with mentalizing, while unfamiliar gestures more strongly activated the posterior region of the pMNS, a finding that is contrary to prior literature and demonstrates the powerful modulatory effects of both motor and perceptual familiarity on pMNS and mentalizing regions when asked to infer the intentions of intransitive gestures.

Innate aversion to ants (Hymenoptera: Formicidae) and ant mimics: experimental findings from mantises (Mantodea)

Field data suggest that ants may be important predators of mantises which, in turn, may be important predators of jumping spiders (Salticidae). Using a tropical fauna from the Philippines as a case study, the reactions of mantises to ants, myrmecomorphic salticids (i.e. jumping spiders that resemble ants) and ordinary salticids (i.e. jumping spiders that do not resemble ants) were investigated in the laboratory. Three mantis species (Loxomantis sp., Orthodera sp., and Statilia sp.) were tested with ten ant species, five species of Myrmarachne (i.e. myrmecomorphic salticids), and 23 ordinary salticid species. Two categories of the myrmecomorphic salticids were recognized: (1) ‘typical Myrmarachne’ (four species with a strong resemblance to ants) and (2) Myrmarachne bakeri (a species with less strong resemblance to ants). Ants readily killed mantises in the laboratory, confirming that, for the mantises studied, ants are dangerous. In alternate-day testing, the mantises routinely preyed on the ordinary salticids, but avoided ants. The mantises reacted to myrmecomorphic salticids similarly to how they reacted to ants (i.e. myrmecomorphic salticids appear to be, for mantises, Batesian mimics of ants). Although myrmecomorphic salticids were rarely eaten, M. bakeri was eaten more often than typical Myrmarachne. Because the mantises had no prior experience with ants, ant mimics or ordinary salticids, our findings suggest that mantises have an innate aversion to attacking ants and that this aversion is generalized to myrmecomorphic salticids even in the absence of prior experience with ants. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 88, 23–32.

Motivational control of goal-directed action

The control of goal-directed, instrumental actions by primary motivational states, such as hunger and thirst, is mediated by two processes. The first is engaged by the Pavlovian association between contextual or discriminative stimuli and the outcome or reinforcer presented during instrumental training. Such stimuli exert a motivational influence on instrumental performance that depends upon the relevance of the associated outcome to the current motivational state of the agent. Moreover, the motivational effects of these stimuli operate in the absence of prior experience with the outcome under the relevant motivational state. The second, instrumental, process is mediated by knowledge of the contingency between the action and its outcome and controls the value assigned to this outcome. In contrast to the Pavlovian process, motivational states do not influence the instrumental process directly; rather, the agent has to learn about the value of an outcome in a given motivational state by exposure to it while in that state. This incentive learning is similar in certain respects to the acquisition of “cathexes” envisaged by Tolman (1949a, 1949b).

Illusions of familiarity.

Feelings of familiarity are not direct products of memory. Although prior experience of a stimulus can produce a feeling of familiarity, that feeling can also be aroused in the absence of prior experience if perceptual processing of the stimulus is fluent (e.g., Whittlesea, Jacoby, & Girard, 1990). This suggests that feelings of familiarity arise through an unconscious inference about the source of processing fluency. The present experiments extend that conclusion. First, they show that a wide variety of feelings about the past are controlled by a fluency heuristic, including feelings about the meaning, pleasantness, duration, and recency of past events. Second, they demonstrate that the attribution process does not rely only on perceptual fluency, but can be influenced even more by the fluency of conceptual processing. Third, they show that although the fluency heuristic itself is simple, people's use of it is highly sophisticated and makes them robustly sensitive to the actual historical status of current events

Craniorachischisis in a Partially Trisomic 11 Fetus in a family with Reproductive Failure and a Reciprocal Translocation, t(6p+;11q−)

A familial reciprocal translocation t(6p+;11q−) is presented, unbalanced (6p+) in the craniorachischisic propositus and balanced in his phenotypically normal father, associated with relative infertility, multiple spontaneous abortions, and failure to...