Exploring the robustness of cross-situational learning under Zipfian distributions

Cross-situational learning has recently gained attention as a plausible candidate for the mechanism that underlies the learning of word-meaning mappings. In a recent study, Blythe and colleagues have studied how many trials are theoretically required to learn a human-sized lexicon using cross-situational learning. They show that the level of referential uncertainty exposed to learners could be relatively large. However, one of the assumptions they made in designing their mathematical model is questionable. Although they rightfully assumed that words are distributed according to Zipf's law, they applied a uniform distribution of meanings. In this article, Zipf's law is also applied to the distribution of meanings, and it is shown that under this condition, cross-situational learning can only be plausible when referential uncertainty is sufficiently small. It is concluded that cross-situational learning is a plausible learning mechanism but needs to be guided by heuristics that aid word learners with reducing referential uncertainty.     

The role of scheduling in learning through observation

In the 2 experiments reported in the present article, participants (N = 40, Experiment 1; N = 60, Experiment 2) learned to solve complex puzzles under different schedules of physical practice, observation, or a combination of the two. The results of both studies indicated that observation, in the absence of any physical practice, allows the development of an accurate but relatively nonfunctional cognitive representation. The data suggest that, even when the motor demands are minimal, the functional significance of the cognitive representation is not maximally realized until physical interaction with the task is possible. Thus, providing the participant with an interspersed practice schedule during acquisition enables that interaction to occur, thereby allowing the absolute number of physical practice trials to be reduced and replaced by observation trials, but leading to equivalent learning.     

The staying power of intercultural learning through reflective inquiry

This paper focuses on the staying power of intercultural knowledge, skills and attitudes for adult students who were engaged in reflective inquiry during a travel course. It addresses a need to assess whether new learning gained from reflection on experience persists over time and what factors may influence staying power. The main finding of the study is that intercultural competence developed through reflective inquiry is maintained and often deepened over time. This builds upon previous findings that skills and characteristics of effective intercultural interaction are advanced through using reflective inquiry to analyze observations and resolve puzzling problems triggered by uncertainty. The context for this qualitative inquiry is with undergraduate adult students participating in a travel course designed to develop intercultural competence. They responded to reflective prompts throughout the course and 18 months after completion. Cases are presented that analyze course and post-course responses. I conclude that the intersection of reflective inquiry and intercultural competence frameworks can influence the ongoing persistence of learning over time.     

The effects of overhearing peers discuss an authority's fairness reputation on reactions to subsequent treatment

Fairness heuristic theory was used to examine how information from one's peers affects an individual's interpretation of, and reactions to, an authority's subsequent behavior. Participants (N=105) overheard their peers discuss an experimenter's reputation (fair, unfair, or absent) before interacting with the experimenter who behaved more versus less fairly. Results showed that the social cues biased participants' subsequent information processing: controlling for the experimenter's behavior, interactional justice mediated the effect of social cues on retaliation. Social cues and the authority's behavior also interacted to predict retaliation. Participants who were treated less fairly retaliated more after being led to expect fair treatment than did participants who heard no prior information about the experimenter.     

The acquisition of morphological knowledge investigated through artificial language learning

Affix knowledge plays an important role in visual word recognition, but little is known about how it is acquired. The authors present a new method of investigating the acquisition of affixes in which participants are trained on novel affixes presented in novel word contexts (e.g., sleepnept). Experiment 1 investigated the role of semantic information on affix acquisition by comparing a form-learning condition with a condition in which participants also received definitions for each novel word. Experiment 2 investigated the role of long-term consolidation on affix acquisition by comparing knowledge of learned affixes two days and nearly two months after training. Results demonstrated that episodic knowledge of affixes can be acquired shortly after a single training session using either form or semantic learning, but suggested that the development of lexicalized representations of affixes requires the provision of semantic information during learning as well as a substantial period of offline consolidation.     

The acquisition of morphological knowledge investigated through artificial language learning

Affix knowledge plays an important role in visual word recognition, but little is known about how it is acquired. The authors present a new method of investigating the acquisition of affixes in which participants are trained on novel affixes presented in novel word contexts (e.g., sleepnept). Experiment 1 investigated the role of semantic information on affix acquisition by comparing a form-learning condition with a condition in which participants also received definitions for each novel word. Experiment 2 investigated the role of long-term consolidation on affix acquisition by comparing knowledge of learned affixes two days and nearly two months after training. Results demonstrated that episodic knowledge of affixes can be acquired shortly after a single training session using either form or semantic learning, but suggested that the development of lexicalized representations of affixes requires the provision of semantic information during learning as well as a substantial period of offline consolidation.     

The role of knowledge of results frequency in learning through observation

The authors examined whether reduced knowledge of results (KR) frequency during observation of a model's performance enhances learning. As they viewed a timing task, observers (n = 54) received KR about the model's performance on each trial (100% KR) or on 1 out of 3 trials (33% KR). Controls (n = 18) received only physical practice; they did not take part in the observation session. The authors also wanted to dissociate the guidance effect of KR during physical practice from the guidance role played by the representation acquired during observation. Therefore, following the observation phase, participants physically performed the task with either the same or a different KR frequency than that experienced during observation. The effects of observation and physical practice on learning were assessed in delayed retention tests. The beneficial effect of reduced KR frequency during observation continued for the following physical practice phases. Possible explanations as to why KR influences observational learning are discussed.     

Intention in motor learning through observation

The purpose of this experiment was to assess whether learning an action through observation is enhanced by the intention to reproduce the observed behaviour. Two groups of participants observed a model practise a timing task and performed a 24-hour delayed retention test. Participants in the first group of observers were explicitly instructed that they would be required to execute the timing task that they had observed as accurately as possible during the delayed retention test. Observers in the second group were instructed that they would be required to describe as accurately as possible the behaviour that they had observed. A control group of participants, who did not observe the model, was also administered the delayed retention test. The results of the retention test indicated that absolute timing (parameterization) was learned by the observers to the same extent with or without intention to reproduce the task. Indeed, on the retention test absolute timing for the two groups of observers was as effective as that for the models. However, observing with an intention to reproduce the task was beneficial for learning the movement's relative timing structure. Results are discussed with respect to a potential mechanism by which intention enhances observation.     

Intention in motor learning through observation

The purpose of this experiment was to assess whether learning an action through observation is enhanced by the intention to reproduce the observed behaviour. Two groups of participants observed a model practise a timing task and performed a 24-hour delayed retention test. Participants in the first group of observers were explicitly instructed that they would be required to execute the timing task that they had observed as accurately as possible during the delayed retention test. Observers in the second group were instructed that they would be required to describe as accurately as possible the behaviour that they had observed. A control group of participants, who did not observe the model, was also administered the delayed retention test. The results of the retention test indicated that absolute timing (parameterization) was learned by the observers to the same extent with or without intention to reproduce the task. Indeed, on the retention test absolute timing for the two groups of observers was as effective as that for the models. However, observing with an intention to reproduce the task was beneficial for learning the movement's relative timing structure. Results are discussed with respect to a potential mechanism by which intention enhances observation.     

The robustness of false memory for emotional pictures

Emotional material is commonly reported to be more accurately recognised; however, there is substantial evidence of increased false alarm rates (FAR) for emotional material and several reports of stronger influences on response bias than accuracy. This pattern is more frequently reported for words than pictures. Research on the mechanisms underlying bias differences has mostly focused on word lists under short retention intervals. This article presents four series of experiments examining recognition memory for emotional pictures while varying arousal and the control over the content of the pictures at two retention intervals, and one study measuring the relatedness of the series picture sets. Under the shorter retention interval, emotion increased false alarms and reduced accuracy. Under the longer retention interval emotion increased hit rates and FAR, resulting in reduced accuracy and/or bias. At both retention intervals, the pattern of valence effects differed based on the arousal associated with the picture sets. Emotional pictures were found to be more related than neutral pictures in each set; however, the influence of relatedness alone does not provide an adequate explanation for all emotional differences. The results demonstrate substantial emotional differences in picture recognition that vary based on valence, arousal and retention interval.     

Young children are more likely to cheat after overhearing that a classmate is smart

Research on moral socialization has largely focused on the role of direct communication and has almost completely ignored a potentially rich source of social influence: evaluative comments that children overhear. We examined for the first time whether overheard comments can shape children's moral behavior. Three‐ and 5‐year‐old children (N = 200) participated in a guessing game in which they were instructed not to cheat by peeking. We randomly assigned children to a condition in which they overheard an experimenter tell another adult that a classmate who was no longer present is smart, or to a control condition in which the overheard conversation consisted of non‐social information. We found that 5‐year‐olds, but not 3‐year‐olds, cheated significantly more often if they overheard the classmate praised for being smart. These findings show that the effects of ability praise can spread far beyond the intended recipient to influence the behavior of children who are mere observers, and they suggest that overheard evaluative comments can be an important force in shaping moral development.     

Regulating recognition decisions through incremental reinforcement learning

Does incremental reinforcement learning influence recognition memory judgments? We examined this question by subtly altering the relative validity or availability of feedback in order to differentially reinforce old or new recognition judgments. Experiment 1 probabilistically and incorrectly indicated that either misses or false alarms were correct in the context of feedback that was otherwise accurate. Experiment 2 selectively withheld feedback for either misses or false alarms in the context of feedback that was otherwise present. Both manipulations caused prominent shifts of recognition memory decision criteria that remained for considerable periods even after feedback had been altogether removed. Overall, these data demonstrate that incremental reinforcement-learning mechanisms influence the degree of caution subjects exercise when evaluating explicit memories.     

Observational learning of tool use in children: Investigating cultural spread through diffusion chains and learning mechanisms through ghost displays

In the first of two experiments, we demonstrate the spread of a novel form of tool use across 20 “cultural generations” of child-to-child transmission. An experimentally seeded technique spread with 100% fidelity along twice as many “generations” as has been investigated in recent exploratory “diffusion” experiments of this type. This contrasted with only a single child discovering the technique spontaneously in a comparable group tested individually without any model. This study accordingly documents children’s social learning of tool use on a new, population-level scale that characterizes real-world cultural phenomena. In a second experiment, underlying social learning processes were investigated with a focus on the contrast between imitation (defined as copying actions) and emulation (defined as learning from the results of actions only). In two different “ghost” conditions, children were presented with the task used in the first experiment but now operated without sight of an agent performing the task, thereby presenting only the information used in emulation. Children in ghost conditions were less successful than those who had watched a model in action and showed variable matching to what they had seen. These findings suggest the importance of observational learning of complex tool use through imitation rather than only through emulation. Results of the two experiments are compared with those of similar experiments conducted previously with chimpanzees and are discussed in relation to the wider perspective of human culture and the influence of task complexity on social learning.