Priming infants to attend to color and pattern information in an individuation task

Wilcox (Cognition 72 (1999) 125) reported that infants are more sensitive to form than surface features when individuating objects in occlusion events: it is not until 7.5 months that infants spontaneously use pattern information, and 11.5 months that they spontaneously use color information, as the basis for object individuation. The present research assessed the extent to which infants' sensitivity to surface features could be increased under more supportive conditions. More specifically, we examined whether younger infants could be primed to draw on color and pattern features in an individuation task if they were first shown the functional value of attending to color and pattern information (i.e. the color or the pattern of an object predicted the function it would engage in). Five experiments were conducted with infants 4.5 to 9.5 months of age. The main findings were that 9.5- and 7.5-month-olds could be primed to use color information, and 5.5- and 4.5-month-olds could be primed to attend to pattern information, after viewing the function events. The results are discussed in terms of the kinds of experiences that can lead to increased sensitivity to surface features and the mechanisms that support feature priming in young infants.     

Developmental differences in shape processing

Considerable evidence indicates that shape similarity plays a major role in object recognition, identification and categorization. However, little is known about shape processing and its development. Across four experiments, we addressed two related questions. First, what makes objects similar in shape? Second, how does the processing of shape similarity develop? We specifically asked whether children and adults determine shape similarity by using categories (e.g., straight vs. curved), as proposed by Biederman (1987), or whether they treat all shape variability uniformly, as proposed by Ullman (1998). Findings from Experiments 1 and 2 suggest that adults and 7-year-olds generally engage in a process in which they impose categories on shape variation and judge objects that fall within those categories as being similar in shape. Four-year-olds are far less likely to engage in such a process. Experiments 3 and 4 address whether 4-year-olds are more likely to treat shape similarity categorically (as older children and adults do) when the objects are given familiar names, functions, and internal properties. Naming did lead to more advanced treatment of shape similarity in some cases. Overall, these findings provide evidence of developmental differences in shape processing and suggest that knowledge of abstract properties of objects may affect the calculation of shape similarity.     

Color-function categories that prime infants to use color information in an object individuation task

There is evidence for developmental hierarchies in the type of information to which infants attend when reasoning about objects. Investigators have questioned the origin of these hierarchies and how infants come to identify new sources of information when reasoning about objects. The goal of the present experiments was to shed light on this debate by identifying conditions under which infants’ sensitivity to color information, which is slow to emerge, could be enhanced in an object individuation task. The outcome of Experiment 1 confirmed and extended previous reports that 9.5-month-olds can be primed, through exposure to events in which the color of an object predicts its function, to attend to color differences in a subsequent individuation task. The outcomes of Experiments 2-4 revealed age-related changes in the nature of the representations that support color priming. This is exemplified by three main findings. First, the representations that are formed during the color-function events are relatively specific. That is, infants are primed to use the color difference seen in the color-function events to individuate objects in the test events, but not other color differences. Second, 9.5-month-olds can be led to form more abstract event representations, and then generalize to other colors in the test events if they are shown multiple pairs of colors in the color-function events. Third, slightly younger 9-month-olds also can be led to form more inclusive categories with multiple color pairs, but only when they are allowed to directly compare the exemplars in each color pair during the present events. These results shed light on the development of categorization abilities, cognitive mechanisms that support color-function priming, and the kinds of experiences that can increase infants’ sensitivity to color information.     

A rose in any other font would not smell as sweet: effects of perceptual fluency on categorization

Fluency--the ease with which people process information--is a central piece of information we take into account when we make judgments about the world. Prior research has shown that fluency affects judgments in a wide variety of domains, including frequency, familiarity, and confidence. In this paper, we present evidence that fluency also plays a role in categorization judgments. In Experiment 1, participants judged a variety of different exemplars to be worse category members if they were less fluent (because they were presented in a smaller typeface). In Experiment 2, we found that fluency also affected judgments of feature typicality. In Experiment 3, we demonstrated that the effects of fluency can be reversed when a salient attribution for reduced fluency is available (i.e., the stimuli are hard to read because they were printed by a printer with low toner). In Experiment 4 we replicated these effects using a within-subject design, which ruled out the possibility that the effects were a statistical artifact caused by aggregation of data. We propose a possible mechanism for these effects: if an exemplar and its category are closely related, activation of one will cause priming of the other, leading to increased fluency. Over time, feelings of fluency come to be used as a valid cue that can become confused with more traditional sources of information about category membership.     

Explaining prompts children to privilege inductively rich properties

Four experiments with preschool-aged children test the hypothesis that engaging in explanation promotes inductive reasoning on the basis of shared causal properties as opposed to salient (but superficial) perceptual properties. In Experiments 1a and 1b, 3- to 5-year-old children prompted to explain during a causal learning task were more likely to override a tendency to generalize according to perceptual similarity and instead extend an internal feature to an object that shared a causal property. Experiment 2 replicated this effect of explanation in a case of label extension (i.e., categorization). Experiment 3 demonstrated that explanation improves memory for clusters of causally relevant (non-perceptual) features, but impairs memory for superficial (perceptual) features, providing evidence that effects of explanation are selective in scope and apply to memory as well as inference. In sum, our data support the proposal that engaging in explanation influences children’s reasoning by privileging inductively rich, causal properties.     

Twelve-month-olds privilege words over other linguistic sounds in an associative learning task

We examined whether 12-month-old infants privilege words over other linguistic stimuli in an associative learning task. Sixty-four infants were presented with sets of either word–object, communicative sound–object, or consonantal sound–object pairings until they habituated. They were then tested on a ‘switch’ in the sound to determine whether they were able to associate the word and/or sound with the novel objects. Infants associated words, but not communicative sounds or consonantal sounds, with novel objects. The results demonstrate that infants exhibit a preference for words over other linguistic stimuli in an associative word learning task. This suggests that by 12 months of age, infants have developed knowledge about the nature of an appropriate sound form for an object label and will privilege this form as an object label.     

Association between Hyperemesis Gravidarum in pregnancy on postnatal ability of infants to attend to a play task with their mother

Research indicates a higher prevalence of attention deficits in children exposed to HG in utero compared to controls with some claiming that the deficit is due to prenatal effects of malnutrition in HG mothers and others that it is due to maternal mental health after birth. The current study examines the effect of hyperemesis gravidarum (HG) diagnosis during pregnancy on infant attention controlling for maternal stress, depression anxiety and attachment. Thirty-eight infants mean age 4 months were videotaped with their mothers (19 mothers with a hyperemesis diagnosis and 19 controls) during play with a soft toy and looking at a picture book. Infant attention was operationalized as gaze direction towards the play activity, mother, and ‘distracted’ (indicated by looking away from play or mother). Mothers completed stress, depression, anxiety, and attachment questionnaires. HG exposed infants attended for significantly less time during play with a book or soft toy compared to controls. Maternal stress, depression, anxiety, and attachment did not differ in HG mothers and controls. Infant ability to attend to the toy, book, mother or being distracted did not relate to maternal postnatal attachment, or mental health. These results suggest that the prenatal environment, especially exposure to HG might be associated with reduced infant attention abilities independent of maternal postnatal health.     

Grammatical gender and inferences about biological properties in german-speaking children

In German, nouns are assigned to one of the three gender classes. For most animal names, however, the assignment is independent of the referent's biological sex. We examined whether German-speaking children understand this independence of grammar from semantics or whether they assume that grammatical gender is mapped onto biological sex when drawing inferences about sex-specific biological properties of animals. Two cross-linguistic studies comparing German-speaking and Japanese-speaking preschoolers were conducted. The results suggest that German-speaking children utilize grammatical gender as a cue for inferences about sex-specific properties of animals. Further, we found that Japanese- and German-speaking children recruit different resources when drawing inferences about sex-specific properties: Whereas Japanese children paralleled their pattern of inference about properties common to all animals, German children relied on the grammatical gender class of the animal. Implications of these findings for studying the relation between language and thought are discussed.     

Basic-level category discriminations by 7- and 9-month-olds in an object examination task

This study examines 7- and 9-month-olds' ability to categorize cats as separate from dogs, and dogs as separate from cats in an object examination task. In Experiment 1, 7- and 9-month-olds (N = 30) familiarized with toy cat replicas were found to form a category of cat that included novel cats but excluded a dog and an eagle. In Experiment 2, 7- and 9-month-olds (N = 30) familiarized with toy dog replicas were found to form a category of dog that included a novel dogs and a novel cat but excluded an eagle. These results mirror those of 3- to 4-month-olds tested with visual preference methods and stand in contrast to previously reported object examination results. Analyses of the distribution of features in the exemplars used to familiarize infants suggest that, like the 3- to 4-month-olds, the 7- and 9-month-olds in these studies form categories within the task, and on the basis of feature distributions.     

Detection of change in shape: an advantage for concavities

Shape representation was studied using a change detection task. Observers viewed two individual shapes in succession, either identical or one a slightly altered version of the other, and reported whether they detected a change. We found a dramatic advantage for concave compared to convex changes of equal magnitude. Observers were more accurate when a concavity along the contour was introduced, or removed, compared to a convexity. This result sheds light on the underlying representation of visual shape, and in particular the central role played by part-boundaries. Moreover, this finding shows how change detection methodology can serve as a useful tool in studying the specific form of visual representations.     

Learning to Manipulate and Categorize in Human and Artificial Agents

This study investigates the acquisition of integrated object manipulation and categorization abilities through a series of experiments in which human adults and artificial agents were asked to learn to manipulate two‐dimensional objects that varied in shape, color, weight, and color intensity. The analysis of the obtained results and the comparison of the behavior displayed by human and artificial agents allowed us to identify the key role played by features affecting the agent/environment interaction, the relation between category and action development, and the role of cognitive biases originating from previous knowledge.     

Statistical inference and sensitivity to sampling in 11-month-old infants

Research on initial conceptual knowledge and research on early statistical learning mechanisms have been, for the most part, two separate enterprises. We report a study with 11-month-old infants investigating whether they are sensitive to sampling conditions and whether they can integrate intentional information in a statistical inference task. Previous studies found that infants were able to make inferences from samples to populations, and vice versa [Xu, F., & Garcia, V. (2008). Intuitive statistics by 8-month-old infants. Proceedings of the National Academy of Sciences of the United States of America, 105, 5012-5015]. We found that when employing this statistical inference mechanism, infants are sensitive to whether a sample was randomly drawn from a population or not, and they take into account intentional information (e.g., explicitly expressed preference, visual access) when computing the relationship between samples and populations. Our results suggest that domain-specific knowledge is integrated with statistical inference mechanisms early in development.     

Effects of signal to noise variability over repeated sessions in an auditory vigilance task

Subjects listened to a sequence of Gaussian noise pulses of 0.5-sec duration, occurring at 2.5-sec intervals. Performance was compared under two conditions: One group detected the occurrence of a 1.8-dB increment in noise pulses; a second group detected the occurrence of increments of 1.3, 1.8, or 2.3 dB. All Ss performed for three 90-min sessions on different days The usual trends were noted for hits and false alarms. TSD indices, d’ and β were also derived. For both groups, it was found that d′ increased slightly over sessions and decreased almost negligibly during sessions, and criterion indices, β generally increased slightly both within and over sessions. Performance was generally comparable under the fixed- and mixed-signal conditions.     

Behavioural reactions to an emotion evoking task in infants at increased likelihood for autism spectrum disorder

Infants at increased likelihood for autism spectrum disorder (ASD) exhibit more negative affect and avoidance behaviour than typically developing infants, and children with ASD express fear differently than typically developing peers. We examined behavioural reactions to emotion-evoking stimuli in infants at increased familial likelihood for ASD. Participants included 55 increased likelihood (IL) infants (i.e., siblings of children diagnosed with ASD) and 27 typical likelihood (TL) infants (i.e., no family history of ASD). At 18 months, we showed infants two masks that commonly elicit fearful responses in older children and examined potential behavioural differences in approach, avoidance, ‘freezing’, crying, gaze aversion, and smiling. At 24 months, infants were assessed with the Toddler Module of the Autism Diagnostic Observation Schedule, 2nd edition (ADOS-2). Results of video-based coding showed that (1) IL infants exhibited more intense avoidance behaviour than TL infants in response to masks, and (2) intensity of avoidance and duration of freezing were positively correlated with ADOS-2 symptom severity scores. Findings suggest that differences in response to emotion-eliciting stimuli may predict later ASD symptoms. Such behavioural differences may inform early detection and intervention in ASD.     

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.     

Categorization and individuation in the cross-race recognition deficit: Toward a solution to an insidious problem

Recent theory and evidence suggest that the Cross-Race Effect (better recognition for same-race (SR) faces than for cross-race (CR) faces) is due to social-cognitive processes of categorization of out-group members, causing perceivers to attend to category-specifying information of CR faces at the expense of individuating information. Three experiments seek to extend this social-cognitive explanation of the CRE by investigating the extent to which the Cross-Race Effect can be reduced by inducing perceivers to individuate rather than categorize CR faces. In all three experiments, participants who received warning of the Cross-Race Effect prior to encoding, and instructions to individuate out-group members, showed no CRE. Experiment 2 suggests that this elimination of the CRE was not due merely to increased motivation to process all stimuli. This is one of few empirical displays of an elimination of the CRE outside of visual training. Moreover, these results are congenial with Levin’s (2000) feature-selection model, which suggests that the CRE is due to differential social cognitions about in-group and out-group members, rather than to differences in perceptual expertise. By eliciting individuation of out-group members at encoding, the CRE can be eliminated.     

Sensitivity to lateral information on a perceptual word identification task in French third and fifth graders

This study aimed at examining sensitivity to lateral linguistic and nonlinguistic information in third and fifth grade readers. A word identification task with a threshold was used, and targets were displayed foveally with or without distractors. Sensitivity to lateral information was inferred from the deterioration of the rate of correct word identification when displayed with distractors. Results show that the two reader groups were sensitive to both right and left lateral information. The area of sensitivity to this information was more extended for the identification of easy words than difficult words. Examination of the detrimental effect of distractors suggests that in both third and fifth graders, the impact of lateral information on foveal processing is the result of a general distraction effect, but also of linguistic processing whose nature remains to be clarified.     

An application of Carnapian inductive logic to an argument in the philosophy of statistics

I claim that an argument from the philosophy of statistics can be improved by using Carnapian inductive logic. Gelman and Shalizi [9] criticise a philosophical account of how statisticians ought to choose statistical models which they call ‘the received view of Bayesian inference’ and propose a different account inspired by falsificationist philosophy of science. I introduce another philosophical account inspired by Carnapian inductive logic and argue that it is even better than Gelman and Shalizi's falsificationist account.     

Sense of agency over thought: external misattribution of thought in a memory task and proneness to auditory hallucination

Previous studies have suggested that auditory hallucination is closely related to thought insertion. In this study, we investigated the relationship between the external misattribution of thought and auditory hallucination-like experiences. We used the AHES-17, which measures auditory hallucination-like experiences in normal, healthy people, and the Deese–Roediger–McDermott paradigm, in which false alarms of critical lure are regarded as spontaneous external misattribution of thought. We found that critical lures elicited increased the number of false alarms as AHES-17 scores increased and that scores of AHES-17 predicted the rate of false memory of critical lures. Furthermore, we revealed that the relationship between AHES-17 scores and the rates of false alarms to critical lures was strictly linear. Therefore, it might be said that individual differences in auditory hallucination-like experiences are highly related to the external misattribution of thought. We discussed these results from the perspective of the sense of agency over thought.