Object manipulation facilitates kind-based object individuation of shape-similar objects

Five experiments investigated the importance of shape and object manipulation when 12-month-olds were given the task of individuating objects representing exemplars of kinds in an event-mapping design. In Experiments 1 and 2, results of the study from Xu, Carey, and Quint (2004, Experiment 4) were partially replicated, showing that infants were able to individuate two natural-looking exemplars from different categories, but not two exemplars from the same category. In Experiment 3, infants failed to individuate two shape-similar exemplars (from Pauen, 2002a) from different categories. However, Experiment 4 revealed that allowing infants to manipulate objects shortly before the individuation task enabled them to individuate shape-similar objects from different categories. In Experiment 5, allowing object manipulation did not induce infants to individuate natural-looking objects from the same category. These findings suggest that object manipulation facilitates kind-based individuation of shape-similar objects by 12-month-olds.     

The role of comparison in preschoolers’ novel object categorization

We examined the role of the comparison process and shared names on preschoolers’ categorization of novel objects. In our studies, 4-year-olds were presented with novel object sets consisting of either one or two standards and two test objects: a shape match and a texture match. When children were presented with one standard, they extended the category based on shape regardless of whether the objects were named. When children were presented with two standards that shared the same texture and the objects were named with the same noun, they extended the category based on texture. The opportunity to compare two standards, in the absence of shared names, led to an attenuation of the effect of shape. These findings demonstrate that comparison plays a critical role in the categorization of novel objects and that shared names enhance this process.     

The differing roles of comparison and contrast in children’s categorization

Comparison of perceptually similar exemplars from an object category encourages children to overlook compelling perceptual similarities and use relational and functional properties more relevant for taxonomic categorization. This article investigates whether showing children a contrasting object that is perceptually similar but out of kind serves the same function as comparison in heightening children’s attention to taxonomically relevant features. In this study, 4-year-olds completed a forced-choice categorization task in which they viewed exemplars from a target category and then selected among (a) a perceptually similar out-of-kind object, (b) a category member that differed perceptually from the exemplars, and (c) a thematically related object. Children were assigned to one of four conditions: No-Compare/No-Contrast, Compare/No-Contrast, No-Compare/Contrast, or Compare/Contrast. As in previous work, comparison increased the frequency of category responses, but there was no effect of contrast on categorization. However, only those in the Compare/Contrast condition displayed consistently taxonomic patterns of responding. Follow-up studies revealed that the effect of comparison plus contrast was evident only when comparison preceded, rather than followed, contrast information and that the value added by providing contrastive information is not attributable to the perceptual similarity between the category exemplars and the contrast object. Comparison and contrast make differing contributions to children’s categorization.     

Matching- and nonmatching-to-sample concept learning in rats using olfactory stimuli

Previous research has shown that rats can learn matching-to-sample relations with olfactory stimuli; however, the specific characteristics of this relational control are unclear. In Experiment 1, 6 rats were trained to either match or nonmatch to sample in a modified operant chamber using common household spices as olfactory stimuli. After matching or nonmatching training with 10 exemplars, the contingencies were reversed with five new stimuli such that subjects trained on matching were shifted to nonmatching and vice versa. Following these reversed contingencies, the effects of the original training persisted for many trials with new exemplars. In Experiment 2, 9 rats were trained with matching procedures in an arena that provided for 18 different spatial locations for comparison stimuli. Five subjects were trained with differential reinforcement outcomes and 4 with only one type of reinforcer. Differential outcomes and multiple exemplars facilitated learning, and there was strong evidence for generalization to new stimuli for most rats that acquired several conditional discriminations. Performances with novel samples were generally above chance, but rarely reached the high levels obtained during baseline with well-trained stimulus relations. However, taken together, the data from the two experiments extend previous work, show that rats can learn both match and nonmatch relations with different experimental protocols, and demonstrate generalization to novel sample stimuli.     

Infants Detect Patterns of Choices Despite Counter Evidence,but Timing of Inconsistency Matters

Understanding others’ preference for a relational category of objects (e.g., prefer darker colored shirts) can be challenging for young children, as it involves comparison of choice options within and across exemplars. Adding to the challenge is occasional inconsistency in choices made by others. Here the authors examined whether 14-month-olds could detect an experimenter’s preference for taller objects when they observed choices that were somewhat inconsistent. Infants watched four familiarization events involving different object pairs: The experimenter chose the taller of two objects thrice and the shorter object once—the inconsistent choice was presented at different time points of familiarization. The infants detected the experimenter’s preference for taller objects only when they had observed three consistent choices consecutively from the beginning. This finding is in line with relational learning, specifically the significant role of initial data in the extraction of relational commonality. It also connects to the hierarchical Bayesian models of rational learning: Inconsistency can be discounted when the initial data allow learners to distinguish a highly probable hypothesis.     

That's More Like It: Multiple Exemplars Facilitate Word Learning

Previous research indicates learning words facilitates categorisation. The current study explores how categorisation affects word learning. In the current study, we investigated whether learning about a category facilitates retention of newly learned words by presenting 2‐year‐old children with multiple referent selection trials to the same object category. In Experiment 1, children either encountered the same exemplar repeatedly or encountered multiple exemplars across trials. All children did very well on the initial task; however, only children who encountered multiple exemplars retained these mappings after a short delay. Experiment 2 replicated and extended this finding by exploring the effect of within‐category variability on children's word retention. Children encountered either narrow or broad exemplars across trials. Again, all children did very well on the initial task; however, only children who encountered narrow exemplars retained mappings after a short delay. Overall, these data offer strong evidence that providing children with the opportunity to compare across exemplars during fast mapping facilitates retention. Copyright © 2013 John Wiley & Sons, Ltd.     

The Influence of Task Dynamics on Inductive Generalizations: How Sequential and Simultaneous Presentation of Evidence Impacts the Strength and Scope of Property Projections

Young children are remarkably flexible reasoners insofar as they modify their inferences to accommodate the conceptual information or perceptual relations represented in an inductive problem. Children’s inductive reasoning is highly sensitive to what evidence is presented to them. Four experiments with 115 preschoolers (M_age = 4;8) and 119 adults (M_age = 21;9) examined whether induction is influenced by how evidence is presented. Specifically, these studies explored the extent to which presenting evidence exemplars at the same time (i.e., simultaneous presentation) or one by one (i.e., sequential presentation) would influence property projections to a range of targets. Experiment 1 revealed that simultaneous presentation yielded a higher rate and a broader scope of projections than did sequential presentation. Experiment 2 confirmed that these effects were not due to how items were labeled. Experiments 3 and 4 explored the interplay between evidence presentation and specific task features that impact how participants compare evidence and target exemplars. In Experiment 3, there were no differences between the 2 presentation formats when evidence exemplars were removed prior to the projection phase, thereby eliminating the opportunity to compare evidence exemplars and targets. Finally, Experiment 4 showed that sequential presentation yielded a high rate of projections when participants were not afforded the opportunity to compare exemplars within the evidence sample. These results have implications for understanding the mechanisms that guide children’s inductive decisions.     

Connecting instances to promote children's relational reasoning

The practice of learning from multiple instances seems to allow children to learn about relational structure. The experiments reported here focused on two issues regarding relational learning from multiple instances: (a) what kind of perceptual situations foster such learning and (b) how particular object properties, such as complexity and similarity, interact with relational learning. Two kinds of perceptual situations were of interest here: simultaneous view, where instances are viewed at once, and sequential view, where instances are viewed one at a time (one right after the other). We examined the influence of particular perceptual situations and object properties using two tests of relational reasoning: a common match-to-sample task, where new instances are compared with a common sample, and a variable match-to-sample task, where new instances are compared with a sample that varies on each trial. Experiments 1 and 2 indicate that simultaneous presentation of even highly dissimilar instances, one simple and one complex, effectively connects them together and improves relational generalization in both match-to-sample tasks. Experiment 3 shows that simple samples are more effective than complex ones in the common match-to-sample task. However, when one instance is not used a common sample and various pairs of instances are simply compared, as in Experiment 4, simple and rich instances are equally effective at promoting relational learning. These results bear on our understanding of how children connect instances and how those initial connections affect learning and generalization.     

Double standards: Memory loading in temporal reference memory

Three experiments compared human performance on temporal generalization tasks with either one or two different, and distinct, standard durations encoded. In the first two experiments participants received presentations of two different standards at the beginning of each trial block and were instructed to encode either one or both of them. When instructed to encode one standard they then had to judge whether each of a number of comparison stimuli was or was not that standard. When instructed to encode both they were then tested using just one of the standards but the participants were unaware, at the time of encoding, which standard would later be used as a reference. No marked effect of the number of temporal standards encoded was found. In Experiment 3 participants received either one or two temporal standards and had to use both when two were presented. This manipulation produced flatter generalization gradients when two standards were encoded than when just one was, and modelling attributed this difference mainly to an increase in reference memory variability in the double-standard case. This suggests that the variability of representation of durations in temporal reference memory can be systematically increased by increasing temporal reference memory load.     

Development of size constancy in children: a test of the proximal mode sensitivity hypothesis

In two experiments, we attempted to replicate Shallo and Rock's (1988) finding that 5- and 6-year-old children exhibit size constancy for a distant object when tested with comparison objects that are matched for visual angle. Experiment 1 (N = 80) included four age groups: 5-, 6-, and 9-year-olds and adults. Participants viewed one standard object from 61 m and indicated which of nine nearby comparison objects matched the standard object in size. The comparison objects subtended equal visual angles in one condition and different visual angles in another. In both conditions, the 5- and 6-year-old children underestimated the size of the standard object, whereas the 9-year-old children and adults made nearly accurate size estimates. In Experiment 2 (N = 32), we replicated the finding that 6-year-old children underestimate size when tested with comparison objects that subtend equal visual angles. Our results conflict with those of Shallo and Rock and support earlier findings that young children do not exhibit size constancy for distant objects.     

See what I mean? An ERP study of the effect of background knowledge on novel object processing

Two event-related potential (ERP) experiments were used to examine the representation of object feature information and background knowledge in semantic memory. Participants were trained on novel object categories with three features and were tested with new exemplars that were complete or were missing one to two features that were essential or nonessential to object function. In both a category membership judgment task (Experiment 1) and a parts detection task (Experiment 2), the N400, a functionally specific measure of semantic access, was graded with feature number but was insensitive to knowledge-based feature importance. A separable ERP effect related to knowledge was seen in Experiment 1 as an enhanced frontocentral negativity (beginning ∼300 msec) to exemplars missing a nonessential versus an essential feature, but this effect did not manifest when background knowledge was less task relevant (Experiment 2). Thus, similarity- and knowledge-based effects are separable, and the locus of knowledge effects varies with task demands but does not seem to arise from facilitated semantic access.     

Repetition, not number of sources, increases both susceptibility to misinformation and confidence in the accuracy of eyewitnesses

Are claims more credible when made by multiple sources, or is it the repetition of claims that matters? Some research suggests that claims have more credibility when independent sources make them. Yet, other research suggests that simply repeating information makes it more accessible and encourages reliance on automatic processes—factors known to change people's judgments. In Experiment 1, people took part in a “misinformation” study: people first watched a video of a crime and later read eyewitness reports attributed to one or three different eyewitnesses who made misleading claims in either one report or repeated the same misleading claims across all three reports. In Experiment 2, people who had not seen any videos read those same reports and indicated how confident they were that each claim happened in the original event. People were more misled by—and more confident about—claims that were repeated, regardless of how many eyewitnesses made them. We hypothesize that people interpreted the familiarity of repeated claims as markers of accuracy. These findings fit with research showing that repeating information makes it seem more true, and highlight the power of a single repeated voice.     

Language Helps Children Succeed on a Classic Analogy Task

Adult humans show exceptional relational ability relative to other species. In this research, we trace the development of this ability in young children. We used a task widely used in comparative research—the relational match‐to‐sample task, which requires participants to notice and match the identity relation: for example, AA should match BB instead of CD. Despite the simplicity of this relation, children under 4 years of age failed to pass this test (Experiment 1), and their performance did not improve even with initial feedback (Experiment 2). In Experiments 3 and 4, we found that two kinds of symbolic‐linguistic experience can facilitate relational reasoning in young children. Our findings suggest that children learn to become adept analogical thinkers, and that language fosters this learning in at least two distinct ways.     

The role of graded category structure in imaginative thought

Participants generated lists of exemplars from the categories of animals, tools, and fruit, and their lists were used to determine the relative accessibility of individual exemplars. Measures of accessibility included output dominance (the number of participants who listed an exemplar), rank (how early instances were listed), and two scores that reflect their combination-output precedence and dominance/rank. Other participants drew and described novel exemplars of those categories that might exist on an imaginary planet and reported on the factors that influenced their creations. References to Earth animals, tools, or fruit were used to determine imagination frequency (the number of participants who mentioned relying on particular Earth exemplars). Items high in accessibility were also high in imagination frequency, implying that those items that come to mind most readily are the ones most likely to serve as starting points for the development of novel ideas. This result held even when task constraints weighed against the use of such items (Experiment 2) and when participants were encouraged to be as creative as possible (Experiment 4), suggesting that it is difficult to avoid the influence of highly accessible category exemplars. Other measures of category structure, including the rated typicality, familiarity, and frequency of exemplars, did not predict imagination frequency as well. The results are discussed in terms of expanding concept boundaries and the inadvertent application of knowledge that is readily accessible.     

Retrieval and comparison processes in part--whole decisions

Undergraduate students were presented with word pairs (e.g., egg-yolk) and were timed as they decided whether one word named part of the thing named by the other word. In Experiment 1, "no" responses to nonpart pairs (e.g., fish-flaps) were slowed by the similarity of the stimulus part (flaps) to a part that the stimulus object did possess (fins). This suggested that decisions were made by retrieving parts of the stimulus object from memory and comparing them to the stimulus part. Whereas the parts used as stimuli in Experiment 1 were nonspecific, belonging to several different types of object (e.g., wheel), those selected for Experiment 2 were specific to a single type of object (e.g., thumb). In Experiment 2, "no" responses to nonpart pairs (e.g., foot-thumb) were slowed by similarity of the stimulus object (foot) to an object that the stimulus part (thumb) belonged to (hand). This suggested that decisions were made by retrieving the object to which the stimulus part belonged and comparing it to the stimulus object. The results support a hybrid model of part-whole decisions that includes directed retrieval of relational knowledge from memory and a comparison process.     

Children's and Adults' Acquisition of Spatial Information: Actual and Simulated Environmental Experience

Undergraduate students were presented with word pairs (e.g., egg-yolk) and were timed as they decided whether one word named part of the thing named by the other word. In Experiment 1, “no” responses to nonpart pairs (e.g., fish-flaps) were slowed by the similarity of the stimulus part (flaps) to a part that the stimulus object did possess (fins). This suggested that decisions were made by retrieving parts of the stimulus object from memory and comparing them to the stimulus part. Whereas the parts used as stimuli in Experiment 1 were nonspecific, belonging to several different types of object (e.g., wheel), those selected for Experiment 2 were specific to a single type of object (e.g., thumb). In Experiment 2, “no” responses to nonpart pairs (e.g., foot-thumb) were slowed by similarity of the stimulus object (foot) to an object that the stimulus part (thumb) belonged to (hand). This suggested that decisions were made by retrieving the object to which the stimulus part belonged and comparing it to the stimulus object. The results support a hybrid model of part-whole decisions that includes directed retrieval of relational knowledge from memory and a comparison process.     

Labelling patterns and object naming

We examined the effects of different labelling patterns on the generalization of object names. Two‐year‐olds, three‐year‐olds and adults were shown two ‘standard’ objects, which were named with the same label, or with two different labels, or with no label at all. Participants were then asked whether objects morphed to be intermediate to the standards belonged to one of the labelled categories or, in the No Label condition, were ‘like’ one of the standards. The Same Label condition showed generalization to all intermediates, whereas the Different Label and No Label conditions showed division of the intermediates into two separate categories, with somewhat sharper division under Different Label. These results suggest two possible mechanisms of lexical learning: ‘boosting’ the equivalence of different exemplars through label identity, and ‘differentiating’ the exemplars through differences in labelling. The studies provided strong evidence for boosting. Learners are sensitive to the distribution of labels across exemplars, and they hold powerful assumptions about the relationship between these distributions and the underlying naming space. These findings have implications for the early emergence of cross‐linguistic differences in lexical learning.     

Establishing arbitrary comparative relations and referential transformations of stimulus function in individuals with autism

Relational Frame Theory posits that complex language develops through arbitrarily applicable relational networks, with potential implications for individuals with autism. Responding relationally based on comparison occurs when participants respond to any number of comparative properties, such as “bigger” or “faster.” Experiment 1 established two 3-member comparative networks, in which a stimulus A was conditioned as “bigger” or “faster” than a stimulus B, and the stimulus B was conditioned as “bigger” or “faster” than a stimulus C in 2 children with autism. Both participants met the mastery criterion for the trained relations and demonstrated the emergence of the untrained combinatorially entailed A–C and C–A relations. The participants could also match the arbitrary A stimuli with larger or faster objects and the C stimuli with smaller or slower objects. The results were replicated in Experiment 2 with the same participants, where a 5-member relational network was established for the bigger/smaller relation.     

Priming infants to use pattern information in an object individuation task: the role of comparison

There is evidence that 4.5-month-olds do not always use surface pattern to individuate objects but that they can be primed to attend to pattern differences through select experiences. For example, if infants are first shown events in which the pattern of an object predicts its function (dotted containers pound and striped containers pour), they will attend to pattern differences in a subsequent individuation task. However, 4.5-month-olds must see multiple exemplars of the pound and pour events and view the dotted and striped containers together during the events. These results suggest that it is the formation of event categories, in which pattern is linked to object function, that supports pattern priming and that direct comparison of the exemplars facilitates the extraction of event categories. The present research investigated conditions that support the comparison process in 4.5-month-olds. The results revealed that the comparison process was initiated only when the dotted and striped containers were seen directly adjacent to each other; if the containers sat far apart, so that infants had to shift their gaze to compare them, event categories were not extracted. In addition, it was comparison of the two patterned containers, and not comparison of the two function events, that was critical to the formation of event categories. These results join a growing body of research indicating the importance of comparison to category formation in infants and reveal the impact of categorization and comparison processes on object individuation in infancy.     

Conditional discrimination in young children: the roles of associative and relational processing

Two experiments examined conditional discrimination in 4- to 6-year-olds. Children learned to choose one of two objects (e.g., circle) when the background was, say, red and to choose the other object (e.g., triangle) when the background was, say, blue. Awareness was assessed and interpreted as a marker of relational processing. In Experiment 1, most 4- and 5-year-olds did not reach the learning criterion. Children in Experiment 2 solved simpler reversal learning problems before the conditional discrimination problems. Most 4- to 6-year-olds reached criterion, but they did not necessarily demonstrate awareness, suggesting that reversal learning and conditional discrimination can be acquired through associative or relational processing. Relational processing increased with age and was used more on simpler problems. Fluid intelligence predicted Problem 2 performance in children who used relational (not associative) processing on Problem 1. Prior experience with simpler problems and awareness of relational structure are influential in children's conditional discrimination.