Grey Parrot (Psittacus erithacus) numerical abilities: addition and further experiments on a zero-like concept

A Grey parrot (Psittacus erithacus), able to quantify 6 or fewer item sets (including heterogeneous subsets) by using English labels (I. M. Pepperberg, 1994), was tested on addition of quantities involving 0-6. He was, without explicit training, asked, "How many total X?" for 2 sequentially presented collections (e.g., of variously sized jelly beans or nuts) and required to answer with a vocal English number label. His accuracy suggested (a) that his addition abilities are comparable to those of nonhuman primates and young children, (b) some limits as to his correlation of "none" and the concept of zero, and (c) a possible counting-like strategy for the quantity 5.     

So many options,so little control: Abstract representations can reduce selection demands to increase children’s self-directed flexibility

Children often struggle to behave flexibly when they must use self-directed goals (e.g., doing homework without prompting) rather than externally driven goals (e.g., cleaning up when told). Such struggles may reflect the demands of selecting among many potential options, as required for self-directed control. The current study tested whether (a) 6-year-old children show difficulty in selecting among competing semantic representations, (b) providing category labels designed to reduce selection demands improves performance, and (c) such benefits transfer to self-directed flexibility. Selection was measured using the blocked cyclic naming task for the first time with children. Pictures were named repeatedly in either homogeneous blocks from the same category (e.g., all animals), which create high selection demands due to spreading semantic activation and engage effortful cognitive control, or mixed blocks with each picture from a different category. Children showed robust difficulty in selecting among options, as indexed by response time (RT) differences between homogeneous and mixed blocks. Providing subcategory labels designed to reduce selection demands by distinguishing among same-category items (e.g., “A cow is a farm animal. A cat is a pet.”) improved selection. Providing superordinate categories (e.g., “A cow is an animal. A cat is an animal.”) also improved selection, but these benefits were less robust, and subcategory labels led to greater benefits than superordinate category labels on a subsequent verbal fluency task. These results support a role for subcategory representations in reducing selection demands to aid self-directed flexibility while suggesting that some children may use superordinate category labels to activate subcategory representations on their own.     

An auditory analog of the picture superiority effect

Previous research has found that pictures (e.g., a picture of an elephant) are remembered better than words (e.g., the word "elephant"), an empirical finding called the picture superiority effect (Paivio & Csapo. Cognitive Psychology 5(2):176-206, 1973). However, very little research has investigated such memory differences for other types of sensory stimuli (e.g. sounds or odors) and their verbal labels. Four experiments compared recall of environmental sounds (e.g., ringing) and spoken verbal labels of those sounds (e.g., "ringing"). In contrast to earlier studies that have shown no difference in recall of sounds and spoken verbal labels (Philipchalk & Rowe. Journal of Experimental Psychology 91(2):341-343, 1971; Paivio, Philipchalk, & Rowe. Memory & Cognition 3(6):586-590, 1975), the experiments reported here yielded clear evidence for an auditory analog of the picture superiority effect. Experiments 1 and 2 showed that sounds were recalled better than the verbal labels of those sounds. Experiment 2 also showed that verbal labels are recalled as well as sounds when participants imagine the sound that the word labels. Experiments 3 and 4 extended these findings to incidental-processing task paradigms and showed that the advantage of sounds over words is enhanced when participants are induced to label the sounds.     

Semantic similarity of labels and inductive generalization: Taking a second look

Prior research suggests that preschoolers can generalize object properties based on category information conveyed by semantically-similar labels. However, previous research did not control for co-occurrence probability of labels in natural speech. The current studies re-assessed children’s generalization with semantically-similar labels. Experiment 1 indicated that adults made category-based inferences regardless of co-occurrence probability; however, 4-year-olds generalized with semantically-similar labels that co-occurred in child-directed speech (e.g., bunny–rabbit) but not with non-co-occurring labels (e.g., crocodile–alligator). Experiment 2 indicated that generalization with semantically-similar labels increased gradually between 4- and 6-years of age. These results are discussed in relation to theories of early learning.     

Mechanisms for accessing lexical representations for output: evidence from a category-specific semantic deficit

We report the performance of a neurologically impaired patient, JJ, whose oral reading of words exceeded his naming and comprehension performance for the same words--a pattern of performance that has been previously presented as evidence for "direct, nonsemantic, lexical" routes to output in reading. However, detailed analyses of JJ's reading and comprehension revealed two results that do not follow directly from the "direct route" hypothesis: (1) He accurately read aloud all orthophonologically regular words and just those irregular words for which he demonstrated some comprehension (as indicated by correct responses or within-category semantic errors in naming and comprehension tasks); and (2) his reading errors on words that were not comprehended at all (but were recognized as words) were phonologically plausible (e.g., soot read as "suit"). We account for these results by proposing that preserved sublexical mechanisms for converting print to sound, together with partially preserved semantic information, serve to mediate the activation of representations in the phonological output lexicon in the task of reading aloud. We present similar arguments for postulating an interaction between sublexical mechanisms and lexical output components of the spelling process.     

Further evidence for addition and numerical competence by a Grey parrot (Psittacus erithacus)

A Grey parrot (Psittacus erithacus), able to quantify sets of eight or fewer items (including heterogeneous subsets), to sum two sequentially presented sets of 0–6 items (up to 6), and to identify and serially order Arabic numerals (1–8), all by using English labels (Pepperberg in J Comp Psychol 108:36–44, 1994; J Comp Psychol 120:1–11, 2006a; J Comp Psychol 120:205–216, 2006b; Pepperberg and Carey submitted), was tested on addition of two Arabic numerals or three sequentially presented collections (e.g., of variously sized jelly beans or nuts). He was, without explicit training and in the absence of the previously viewed addends, asked, “How many total?” and required to answer with a vocal English number label. In a few trials on the Arabic numeral addition, he was also shown variously colored Arabic numerals while the addends were hidden and asked “What color number (is the) total?” Although his death precluded testing on all possible arrays, his accuracy was statistically significant and suggested addition abilities comparable with those of nonhuman primates.     

Naming practices,typicality, and underextension in child language

Preschool children (3 to 5 years of age) in an initial study underextended superordinate labels. The labels (e.g., food) were not applied to category instances that were rated as atypical by adults (e.g., ketchup). In a second experiment, mothers seldom used a superordinate term in referring to pairs of the same atypical instances, but they did label pairs of typical instances with a superordinate. A third experiment demonstrated the effects of several word-referent modeling conditions on young children's comprehension of a superordinate term. The results were viewed as suggesting that the child undergeneralizes superordinate labels because adult naming practices are such that category instances having certain functional or perceptual attributes may be labeled with a superordinate, while other, dissimilar instances are almost always labeled with subordinate names instead of a superordinate.     

Classes and collections: Conceptual organization and numerical abilities

Collections (e.g., forest, army) and classes (e.g., trees, soldiers) are natural concepts that differ in their organizational principles. Collections are organized into part-whole relations (e.g., trees are parts of a forest). Classes are organized according to class inclusion relations (e.g., oaks are kinds of trees). Because of their part-whole organization, collections are assumed to have greater psychological coherence than classes and therefore an advantage on tasks that require thinking about an aggregate as well as the individuals in it. Number requires aggregate analysis since it is a characteristic of sets, not of individuals. Four studies tested the hypothesized collection advantage in numerical reasoning tasks. In each, children viewed identical displays that were labeled with either class or collection terms. With perceptual input constant, the collection labels in contrast to the class labels promoted children's insight into certain numerical principles and facilitated the use of these principles in a variety of numerical tasks. Collection labels appear to induce a cognitive reorganization of importance to the child: the shift from inclusion to part-whole relations.     

Verbal response-effect compatibility

Ideomotor theory states that motor responses are activated by an anticipation of their sensory effects. We assumed that anticipated effects would produce response-effect (R-E) compatibility when there is dimensional overlap of effects and responses. In a four-choice task, visual digit stimuli called for verbal responses (color names). Each response produced a written response-effect on the screen. In different groups, the response-effect was a colored color word (e.g., blue in blue), a white color word, or a colored nonword (Xs in blue). In different blocks, the predictable effects were either incompatible (e.g., response "blue" --> effect: green) or compatible with the response. We found faster responses with compatible than with incompatible R-E mappings. The compatibility effect was strongest with colored words, intermediate with white words, and smallest with colored nonwords. We conclude that effect anticipation influences response selection on both a perceptual level (related to the word's color) and a conceptual level (related to the word's meaning).     

Authorial intentions and metaphor comprehension

Three experiments investigated the role of authorial intentions in metaphor comprehension. In these studies, subjects read metaphoric (e.g., A family album is like a museum), literal (e.g., An art gallery is like a museum), and anomalous (e.g., A tortoise shell is like an art gallery) comparisons and rated their degreeof meaningfulness (Experiment 1), made speeded decisions as to whether each phrase was meaningful or not (Experiment 2), or wrote out interpretations of each comparison statement (Experiment 3). The subjects were tolt that the comparisons were written either by famous 20th century poets or by a computer program that randomly generated the statements from a list of words. Our general hypothesis was that knowing that intentional agents (the poets) authored the different comparisons should facilitate subjects' comprehension of the metaphors. Experiment 1 showed that subjects rated both metaphoric and literal comparisons as being more meaningful in the poet condition than when these statements were supposedly written by computer. Experiment 2 demonstrated that subjects were faster in making their meaningfulness judgments for metaphors in the poet condition than in the computer context, but that subjects were also slower in rejecting anomalous comparisons when these were supposedly written by the poets. Experiment 3 indicated that subjects produced more meanings or interpretations for comparisons presumably written by poets than by computer. These results highlight the improtance of implied, authorial intentions in understanding metaphorical statements. We discuss the implications of this work for psycholinguistic theories of figurative language comprehension, as well as for theories of literary interpretation.     

What’s in the name? Or how rocks and stones are different from bunnies and rabbits

Labels have been shown to play an important role in inductive generalization; however, the mechanism by which labels contribute to generalization early in development remains unclear. We investigated two factors that may influence the inductive potential of labels: semantic similarity and co-occurrence probability. Results suggested that adults and 6-year-olds rely on semantic similarity of labels and that their generalizations are not affected by co-occurrence probability. Specifically, generalization patterns were qualitatively similar for co-occurring semantically similar labels (e.g., bunny-rabbit) and non-co-occurring semantically similar labels (e.g., rock-stone) in 6-year-olds and adults. Unlike 6-year-olds and adults, 4-year-olds were likely to generalize co-occurring labels but not non-co-occurring labels. Possible mechanisms by which co-occurrence probability may influence label generalization in young children are discussed.     

Children's interpretation of generic noun phrases

Generic utterances (e.g., "Cows say 'moo'") have 2 distinctive semantic properties: (a) Generics are generally true, unlike indefinites (e.g., "Bears live in caves" is generic; "I saw some bears in the cave" is indefinite), and (b) generics need not be true of all category members, unlike universal quantifiers (e.g., all, every, each). This article examined whether preschool children and adults appreciate both these features, using a comprehension task (Study 1) and an elicited production task (Study 2). In both tasks, 4-year-old children--like adults--treated generics as distinct from both indefinites ("some") and universal quantifiers ("all"). In contrast, 3-year-olds did not differentiate among generics, "all," and "some." By 4 years of age, generics emerge as a distinct semantic device.     

What very small numbers mean

This article presents a theoretical and experimental framework for assessing the biases associated with the interpretation of numbers. This framework consists of having participants convert between different representations of quantities. These representations should include both variations in numerical labels that symbolize quantities and variations in displays in which quantity is inherent. Five experiments assessed how people convert between relative frequencies, decimals, and displays of dots that denote very low proportions (i.e., proportions below 1%). The participants demonstrated perceptual, response, and numerical transformation biases. Furthermore, the data suggest that relative frequencies and decimals are associated with different abstract representations of amount.     

Young children's use of syntactic cues to learn proper names and count nouns

In 6 experiments, 144 toddlers were tested in groups ranging in mean age from 20 to 37 months. In all experiments, children learned a novel label for a doll or a stuffed animal. The label was modeled syntactically as either a count noun (e.g., "This is a ZAV") or a proper name (e.g., "This is ZAV"). The object was then moved to a new location in front of the child, and a second identical-looking object was placed nearby. The children's task was to choose 1 of the 2 objects as a referent for the novel word. By 24 months, both girls (Experiment 2) and boys (Experiment 5) were significantly more likely to select the labeled object if they heard a proper name than if they heard a count noun. At 20 months, neither girls (Experiments 1 and 6) nor boys (Experiment 1) demonstrated this effect. By their 2nd birthdays, children can use syntactic information to distinguish appropriately between labels for individual objects and those for object categories.     

相似和相同语言标签对幼儿归纳推理的影响

为进一步检验相似语言标签的效应,采用经典的三角属性归纳范式,通过两个实验研究了"相似/相同"的真实语言标签对4岁幼儿归纳推理的影响.在实验一中,三角范式中的三个刺激物属于同一类别,在实验二中,三个刺激物属于两种不同的类别.每个实验均有三种条件:在控制条件中,实验者用"这个"指代每个客体;在相似语言标签条件中,靶刺激与知觉不相似的比较刺激具有相同的、且暗示了类别成员关系的词素(例如,翠鸟—飞机—鸵鸟);在相同语言标签条件中,靶刺激和知觉不相似的比较刺激共享相同的语言标签(例如,鸟—飞机—鸟).结果一致显示,与控制条件相比,幼儿在相似语言标签条件下表现出了更多的基于概念的归纳,表明在真实语言标签条件下也存在相似语言标签效应.同时,研究结果也显示,幼儿在相似和相同语言标签条件下的归纳没有显著差异,说明语言标签在幼儿归纳中更可能传递了概念信息,从而挑战了Sloutsky等的理论.     

Contribution of visual and semantic proximity to identification performance in a viral encephalitis patient

Identification deficits were investigated in F.S., a patient with herpes simplex viral encephalitis. F.S.'s confrontation naming abilities were assessed for multiple repetitions of 12 line drawings of artifacts. Six of the line drawings consisted of psychologically "close" objects (i.e., objects that share many visual and semantic features with other objects) and 6 were psychologically "disparate" objects (i.e., objects that share few, if any, visual and semantic features with other objects). F.S. correctly named all of the objects from the "disparate" category but only 47% of the objects from the "close" category. We also tested F.S. using novel, computer-generated shapes that were paired with artifact labels. We paired semantically close or disparate labels to shapes and F.S. attempted to learn these pairings. Overall, F.S.'s shape-label confusions were most detrimentally affected when we used labels that referred to objects that were visually close and semantically distinct. Results indicate that, at least for our patient, visual similarity contributed the most to his identification errors.     

Talking about proportion: Fraction labels impact numerical interference in non‐symbolic proportional reasoning

Across two experiments, we investigated how verbal labels impact the way young children attend to proportional information, well before the introduction of formal fraction education. Five‐ to seven‐year‐old children were introduced to equivalent non‐symbolic proportions labeled in one of three ways: (a) a single, categorical label for multiple fractions (both 3/4 and 6/8 referred to as “blick”), (b) labels that focused on the numerator [e.g., 3/4 labeled as “three blicks” (Experiment 1) or “three‐fourths” (Experiment 2)], or (c) labels that had a complete part‐whole structure (“three‐out‐of‐four”). Children then completed measures of non‐symbolic proportional reasoning that pitted whole‐number information against proportional information for novel proportions. Across both experiments, children who heard the categorical labels were more likely to match non‐symbolic displays based on proportion than children in any of the other conditions, who demonstrated higher levels of numerical interference. These findings suggest that fraction labels have the potential to shape children's attention to proportional information even in the context of non‐symbolic part‐whole displays and for children who are not familiar with formal fraction symbols. We discuss these findings in terms of children's developing understanding of proportional reasoning and its implications for fraction education.     

This cat has nine lives? Children's memory for genericity in language

Generic noun phrases ("Birds lay eggs") are important for expressing knowledge about abstract kinds. The authors hypothesized that genericity would be part of gist memory, such that young children would appropriately recall whether sentences were presented as generic or specific. In 4 experiments, preschoolers and college students (N = 280) heard a series of sentences in either generic form (e.g., "Bears climb trees") or specific form (e.g., "This bear climbs trees") and were asked to recall the sentences following a 4-min distractor task. Participants in all age groups correctly distinguished between generic and specific noun phrases (NPs) in their recall, even when forgetting the details of the NP form. Memory for predicate content (e.g., "climb trees") was largely unaffected by genericity, although memory for category labels (e.g., "bear") was at times better for those who heard sentences with generic wording. Overall, these results suggest that generic form is maintained in long-term memory even for young children and thus may serve as the foundation for constructing knowledge about kinds.     

Quantity discrimination in fish species: fish use non-numerical continuous quantity traits to select shoals

Fish typically prefer to live in big shoals due to the associated ecological benefits. Shoaling is a behavior that depends on the ability to quantitatively discriminate. The fundamental mechanism involved in quantity discrimination determines whether fish can discriminate a shoal using numerical discrete cues (e.g., number of shoal members), non-numerical continuous traits (e.g., total body surface area) or both; however, the mechanism is currently a controversial topic. In the present study, we used a spontaneous choice experiment to test whether guppy (Poecilia reticulata), zebrafish (Danio rerio), Chinese crucian carp (Carassius auratus) and qingbo (Spinibarbus sinensis) rely on continuous (i.e., body surface area) or discrete (i.e., number of shoal members) information for shoal selection by altering the body surface area (cumulative body surface area ratio of 3:2 or 1:1) between two stimulus shoals with a different number of members (2 individuals vs 3 individuals). All four fish species preferred to shoal with the stimulus shoal with the larger cumulative surface area even if the shoal had fewer members; however, fish showed no shoal preference when the cumulative surface body areas of both stimulus shoals were equal. Furthermore, qingbo did not numerically discriminate between a shoal with 1 individual and a shoal with 3 individuals when the cumulative surface areas of both stimulus shoals were equal; however, qingbo showed a preference for the shoal with the larger cumulative surface area when the two stimulus shoals each had 3 individuals. In conclusion, the present study demonstrated that all four fish species relied only on non-numerical continuous quantity information for shoal selection, at least under a difficult task (i.e., 2 vs 3).