A little learning is a dangerous thing: An experimental demonstration of ignorance-driven inference

Studies of ignorance-driven decision making have been employed to analyse when ignorance should prove advantageous on theoretical grounds or else they have been employed to examine whether human behaviour is consistent with an ignorance-driven inference strategy (e.g., the recognition heuristic). In the current study we examine whether—under conditions where such inferences might be expected—the advantages that theoretical analyses predict are evident in human performance data. A single experiment shows that, when asked to make relative wealth judgements, participants reliably use recognition as a basis for their judgements. Their wealth judgements under these conditions are reliably more accurate when some of the target names are unknown than when participants recognize all of the names (a “less-is-more effect”). These results are consistent across a number of variations: the number of options given to participants and the nature of the wealth judgement. A basic model of recognition-based inference predicts these effects.     

Diagnosticity and prototypicality in category learning: a comparison of inference learning and classification learning

Category knowledge allows for both the determination of category membership and an understanding of what the members of a category are like. Diagnostic information is used to determine category membership; prototypical information reflects the most likely features given category membership. Two experiments examined 2 means of category learning, classification and inference learning, in terms of sensitivity to diagnostic and prototypical information. Classification learners were highly sensitive to diagnostic features but not sensitive to nondiagnostic, but prototypical, features. Inference learners were less sensitive to the diagnostic features than were classification learners and were also sensitive to the nondiagnostic, prototypical, features. Discussion focuses on aspects of the 2 learning tasks that might lead to this differential sensitivity and the implications for learning real-world categories.     

A further investigation of category learning by inference

Categories are learned in many ways besides by classification, for example, by making inferences about classified items. One hypothesis is that classifications lead to the learning of features that distinguish categories, whereas inferences promote the learning of the internal structure of categories, such as the typical features. Experiment 1 included single-feature and full-feature classification tests following either classification or inference learning. Consistent with predictions, inference learners did better on the single tests but worse on the full tests. Experiment 2 further showed that inference learners, unlike classification learners, were no better at classifying items that they had seen at study compared with equally typical items they had not seen at study. Experiment 3 showed that features queried about during inference learning were classified better than ones not queried about, although even the latter features showed some learning on single-feature tests. The discussion focuses on how different types of category learning lead to different category representations.     

A demonstration of observational learning in rats using a bidirectional control

Hungry rats observed a conspecific demonstrator pushing a single manipulandum, a joystick, to the right or to the left for food reward and were then allowed access to the joystick from a different orientation. The effects of right-pushing vs left-pushing observation experience on (1) response acquisition, (2) reversal of a left-right discrimination, and (3) responding in extinction, were examined. Rats that had observed left-pushing made more left responses during acquisition than rats that had observed right-pushing, and rats that had observed demonstrators pushing in the direction that had previously been reinforced took longer to reach criterion reversal and made more responses in extinction than rats that had observed demonstrators pushing in the opposite direction to that previously reinforced. These results provide evidence that rats are capable of learning a response, or a response-reinforcer contingency, through conspecific observation.     

A little labeling goes a long way: Semi‐supervised learning in infancy

There is considerable evidence that labeling supports infants' object categorization. Yet in daily life, most of the category exemplars that infants encounter will remain unlabeled. Inspired by recent evidence from machine learning, we propose that infants successfully exploit this sparsely labeled input through “semi‐supervised learning.” Providing only a few labeled exemplars leads infants to initiate the process of categorization, after which they can integrate all subsequent exemplars, labeled or unlabeled, into their evolving category representations. Using a classic novelty preference task, we introduced 2‐year‐old infants (n = 96) to a novel object category, varying whether and when its exemplars were labeled. Infants were equally successful whether all exemplars were labeled (fully supervised condition) or only the first two exemplars were labeled (semi‐supervised condition), but they failed when no exemplars were labeled (unsupervised condition). Furthermore, the timing of the labeling mattered: when the labeled exemplars were provided at the end, rather than the beginning, of familiarization (reversed semi‐supervised condition), infants failed to learn the category. This provides the first evidence of semi‐supervised learning in infancy, revealing that infants excel at learning from exactly the kind of input that they typically receive in acquiring real‐world categories and their names.     

Costs and benefits of autonomy when learning a task: an experimental approach

Previous findings suggested that the positive relationship between autonomy and learning outcomes (such as improved task performance) only holds up until a certain optimum level of autonomy has been reached. This assumption was investigated in an experimental study where 95 participants had to learn a computer task. During the learning phase, we manipulated autonomy, distinguishing among no, moderate, and full autonomy. The results revealed that, when learning a task, having autonomy is preferred to having no autonomy. However, increases in autonomy beyond a certain level (i.e., full versus moderate autonomy) will not yield additional advantages regarding the motivation to learn and learning outcomes, and may have disadvantages in terms of learning efficiency.     

Empathy is a beautiful thing: Empathy predicts imitation only for attractive others

Research shows that we spontaneously imitate people. Moreover, empathy predicts the degree of this non‐conscious imitation. Little is known, however, if or how this expression of empathy is influenced by stable physical characteristics of our interaction‐partners. In two studies, we tested whether attractiveness of others moderated the relation between empathy and imitation. While seeing a woman performing joystick movements, participants either imitated, or non‐imitated these movements. Results showed that the higher participants empathy score, the faster they imitated an attractive person. The level of empathy did not predict the degree of imitation of unattractive targets. The findings demonstrate that the expression of empathy through imitation can be moderated by attractiveness, thereby introducing a new dimension to the conditionality of empathy.     

Analogical inference: the role of awareness in abstract learning

The acquisition and flexible expression of complex relations is often attributed to declarative memory processes. The extent to which such tasks may be done implicitly has not been sufficiently explored. We report that analogical or transfer processes may be accomplished implicitly. Our analogy task requires acquisition of a transverse patterning set, and then tests for transfer on an unrelated set. Participants learn the relations A>B (given a choice between A and B choose A) and B>C and the unrelated set X>Y and Y>Z. Only the experimental group was trained on the transverse pair C>A. At test all trials are unreinforced: A?B, B?C, A?C, X?Y, Y?Z, X?Z. Analogy was observed when the experimental group chose Z>X at greater frequency than controls who uniformly chose X>Z. Analogy occurred with or without awareness of the transfer. The capacity to transfer relations to an analogous set demonstrates a level of flexibility and abstraction not generally thought to be possible for implicit processes.     

Analogical inference: The role of awareness in abstract learning

The acquisition and flexible expression of complex relations is often attributed to declarative memory processes. The extent to which such tasks may be done implicitly has not been sufficiently explored. We report that analogical or transfer processes may be accomplished implicitly. Our analogy task requires acquisition of a transverse patterning set, and then tests for transfer on an unrelated set. Participants learn the relations A>B (given a choice between A and B choose A) and B>C and the unrelated set X>Y and Y>Z. Only the experimental group was trained on the transverse pair C>A. At test all trials are unreinforced: A?B, B?C, A?C, X?Y, Y?Z, X?Z. Analogy was observed when the experimental group chose Z>X at greater frequency than controls who uniformly chose X>Z. Analogy occurred with or without awareness of the transfer. The capacity to transfer relations to an analogous set demonstrates a level of flexibility and abstraction not generally thought to be possible for implicit processes.     

Autonomy in children's learning: an experimental and individual difference investigation

Ninety-one fifth-grade children participated in a study that assessed the effects of motivationally relevant conditions and individual differences on emotional experience and performance on a learning task. Two directed-learning conditions, one controlling and one noncontrolling, were contrasted with each other and with a third nondirected, spontaneous-learning context. Both directed sets resulted in greater rote learning compared with the nondirected-learning condition. However, both the nondirected and the noncontrolling directed-learning sets resulted in greater interest and conceptual learning compared with the controlling set, presumably because they were more conducive to autonomy or an internal perceived locus of causality. Furthermore, children in the controlling condition experienced more pressure and evidenced a greater deterioration in rote learning over an 8-(+/- 1) day follow-up. Individual differences in children's autonomy for school-related activities as measured by the Self-Regulation Questionnaire (Connell & Ryan, 1985) also related to outcomes, with more self-determined styles predicting greater conceptual learning. Results are discussed in terms of the role of autonomy in learning and development and the issue of directed versus nondirected learning.     

壶中别有日月天--内丹隐语"壶"之源流

壶 ,古器名 ,深腹 ,敛口 ,用以盛酒浆或粮食。《诗·豳风·七月》:“八月断壶” ,指的是壶卢 ,现在写作葫芦。俗话说的“不知葫芦里卖的什么药”就与它的用途有关。道教的“八仙”之一铁拐李 ,就常背一个药葫芦 ,周游江湖 ,治病救人。神话小说《西游记》第五回中说 :“大圣直至丹房里面 ,寻访 (老君 )不遇 ,但见丹灶之旁 ,炉中有火。炉左右安放着五个葫芦 ,葫芦里都是炼就的金丹……他就把那葫芦都倾出来 ,就都吃了 ,如吃炒豆相似。”本文要谈的就是道家、道教中的壶。因为古代的游医习惯用葫芦装药 ,所以“悬壶”就成了行医的代名词 ,这个…     

Confirmation bias in a simulated research environment: An experimental study of scientific inference

Numerous authors (e.g., Popper, 1959) argue that scientists should try to falsify rather than confirm theories. However, recent empirical work (Wason and Johnson-Laird, 1972) suggests the existence of a confirmation bias, at least on abstract problems. Using a more realistic, computer controlled environment modeled after a real research setting, subjects in this study first formulated hypotheses about the laws governing events occurring in the environment. They then chose between pairs of environments in which they could: (I) make observations which would probably confirm these hypotheses, or (2) test alternative hypotheses. Strong evidence for a confirmation bias involving failure to choose environments allowing tests of alternative hypotheses was found. However, when subjects did obtain explicit falsifying information, they used this information to reject incorrect hypotheses.     

Refutation of Poffenberger's inference: an existence proof and a countermodel

Interhemispheric relay time (IHRT) is inferred from simple (visual) reaction time (SRT) by subtracting SRTs in ipsilateral hand-field conditions from SRTs in contralateral hand-field conditions. This index, the "crossed-uncrossed differential" (CUD) is a synonym of IHRT in the current literature. The CUD has been shown to be significantly moderated by experimental variables, including attentional. One reason the CUD = IHRT hypostasy persists today is that no experimental manipulation has yet been able to generate a significantly negative CUD in a subject manifesting a significant positive CUD in classical conditions. We implemented an experimental manipulation, in SRT, consisting of increasing complexity of the response after the initial key press required at detection. In a very large scale single-case experiment, we found that the CUD thus went from significantly positive in classical SRT to significantly negative in the increased response load condition.