Spontaneous non‐verbal counting in toddlers

A wealth of studies have investigated numerical abilities in infants and in children aged 3 or above, but research on pre‐counting toddlers is sparse. Here we devised a novel version of an imitation task that was previously used to assess spontaneous focusing on numerosity (i.e. the predisposition to grasp numerical properties of the environment) to assess whether pre‐counters would spontaneously deploy sequential (item‐by‐item) enumeration and whether this ability would rely on the object tracking system (OTS) or on the approximate number system (ANS). Two‐and‐a‐half‐year‐olds watched the experimenter performing one‐by‐one insertion of ‘food tokens’ into an opaque animal puppet and then were asked to imitate the puppet‐feeding behavior. The number of tokens varied between 1 and 6 and each numerosity was presented many times to obtain a distribution of responses during imitation. Many children demonstrated attention to the numerosity of the food tokens despite the lack of any explicit cueing to the number dimension. Most notably, the response distributions centered on the target numerosities and showed the classic variability signature that is attributed to the ANS. These results are consistent with previous studies on sequential enumeration in non‐human primates and suggest that pre‐counting children are capable of sequentially updating the numerosity of non‐visible sets through additive operations and hold it in memory for reproducing the observed behavior.     

Human nonverbal counting estimated by response production and verbal report

In three experiments, people were shown sequential displays and were prevented from verbal counting by being required to perform other cognitive tasks. In Experiment 1, the subjects were shown three 1.target (target5 = 8, 16, or 32) sequences of colored geometric shapes. On occasional question trials, the subjects were asked to estimate the target number after the final item in the sequence. On other test trials, items continued to appear beyond the target, and the subjects estimated the target manually by tapping a space bar. In Experiments 2 and 3, a matching-to-sample procedure required the subjects to estimate the same sequence of items (target = 8, 11, 14, 17, or 20) both verbally and manually. The results indicated that (1) manual and verbal estimates closely approximated target size in Experiments 1 and 2, (2) coefficients of variation were constant across target size, and (3) correlations between manual and verbal estimates were positive in Experiments 2 and 3. Requiring the subjects to perform a counting task during presentation of items led to underestimation of number in Experiment 3. nt]mis|This research was funded by a research grant from the Natural Sciences and Engineering Research Council of Canada to W.A.R. and by the Ontario Graduate Scholarship in Science and Technology and the Ontario Graduate Scholarship to M.J.B.     

Variability signatures distinguish verbal from nonverbal counting for both large and small numbers

Humans appear to share with animals a nonverbal counting process. In a nonverbal counting condition, subjects pressed a key a numeral-specified number of times, while saying “the” at every press. The mean number of presses increased as a power function of the target number, with a constant coefficient of variation (c.v.), both within and beyond the proposed subitizing range (1–4 or 5), suggesting small numbers are represented on the same continuum as larger numbers and subject to the same noise process (scalar variability). By contrast, when subjects counted their presses out loud as fast as they could, the c.v. decreased as the inverse square root of the target value (binomial variability instead of scalar variability). The unexpected power-law relation between target value and mean number of presses in nonverbal counting suggests a new hypothesis about the development of the function relating number symbols to mental magnitudes.     

A Preverbal Perspective on Conversion Disorder

ABSTRACT

In contrast to the vast majority of writings on hysteria that place its genesis within the Oedipal period, this article conceptualizes a preverbal, pre-Oedipal origin for the primary manifestation of hysteria—conversion disorder. Findings from infant observation research are used to support a conceptualization that includes connections to temperament, attachment strategies, Wilma Bucci’s multiple code theory, and Leslie Farber’s perspectives on will and willfulness. This article suggests an etiology that is dependent on a complexity of factors operating interactively and within the context of a relational process.     

Preverbal error-monitoring in stutterers and fluent speakers

This study was designed to characterize the brain system that monitors speech in people who stutter and matched controls. We measured two electrophysiological peaks associated with action-monitoring: the error-related negativity (ERN) and the error positivity (Pe). Both the ERN and Pe were reliably observed after errors in a rhyming task and a nonverbal flanker task, replicating previous reports of a language-monitoring ERN and demonstrating that the Pe can also be elicited by phonological errors. In the rhyming task, stutterers showed a heightened ERN peak regardless of whether they actually committed an error. Similar results, though only marginally significant, were obtained from the flanker task. These results support the vicious cycle hypothesis, which posits that stuttering results from over-monitoring the speech plan. The elevation of the ERN in stutterers and the similarity of the results between the flanker and rhyming tasks implies that speech-monitoring may rely on the same neural substrate as action-monitoring.     

Preverbal children with autism understand the intentions of others

There is a ‘theory of mind’ theory of autism. Meltzoff has recently developed a procedure that gives a nonverbal assessment of ‘theory of mind’. A group of children with autism and a matched control group of normally developing infants were given three of Meltzoff’s tasks and three conventional, gestural imitation tasks. The children with autism showed the expected deficits on gestural imitation, but were significantly better than the normally developing infants on the Meltzoff tasks. The implications of these results for a number of theoretical issues are discussed.     

The relationship between non‐verbal systems of number and counting development: a neural signatures approach

Two non‐verbal cognitive systems, an approximate number system (ANS) for extracting the numerosity of a set and a parallel individuation (PI) system for distinguishing between individual items, are hypothesized to be foundational to symbolic number and mathematics abilities. However, the exact role of each remains unclear and highly debated. Here we used an individual differences approach to test for a relationship between the spontaneously evoked brain signatures (using event‐related potentials) of PI and the ANS and initial development of symbolic number concepts in preschool children as displayed by counting. We observed that individual differences in the neural signatures of the PI system, but not the ANS, explained a unique portion of variance in counting proficiency after extensively controlling for general cognitive factors. These results suggest that differences in early attentional processing of objects between children are related to higher‐level symbolic number concept development.     

Conditional Discriminations by Preverbal Children in an Identity Matching-to-Sample Task

This study sought to develop methodology for assessing whether children aged 16-21 months could learn to match stimuli on the basis of physical identity in conditional discrimination procedures of the type routinely used in stimulus equivalence research with older participants. The study was conducted in a private room at a daycare center for children and toddlers. The child and the research sat together on the floor facing an apparatus with two windows. Stimuli to be discriminated were toys especially designed to attract the child's attention and maintain continued interest. On simple discrimination and discrimination reversal trials that were programmed in initial training, S+ and S- toys were displayed within the two windows. When the child touched the window containing the toy defined as S+ on a given trial, s/he was allowed to manipulate/play with that toy. Selections of the S- toy ended the trial without a play opportunity. On subsequent identity matching-to-sample trials, the child was first allowed to manipulate a sample toy. Then, S+ (matching) and S- (nonmatching) comparison toys were displayed within the windows, and the selection consequences were the same as on simple discrimination trials. The study provides evidence that preverbal children can master simple and conditional discrimination performances via such procedures, perhaps setting the stage for subsequent studies aimed at establishing procedural control of the discrimination baselines needed to assess the stimulus equivalence potential of children in this age range.     

Right-hemispheric damage and verbal problem solving behavior.

Patients with right-hemisphere damage, who ostensibly have no linguistic impairment, are relatively incapable of solving two-term series problems in which comparative adjectives in the premise and question are antonymic. This finding suggests that such verbal reasoning depends, in part, upon nonlinguistic imaginal processes subserved by the right hemisphere. In this manner, the right hemisphere is often required for the full elaboration of linguistic input.     

Aging and interference in verbal working memory.

According to inhibitory views of working memory, old adults should have particular problems deleting irrelevant information from working memory, leading to greater interference effects compared with young adults. The authors investigated this hypothesis by using variations of an A-B, C-D retroactive interference paradigm in working memory with young and old adults. They used a recognition measure of memory, assessing both accuracy and reaction time. The primary finding was that senior adults consistently exhibited proportionally greater retroactive interference effects compared with young adults when interfering word pairs that had been read aloud had to be rejected. Patterns of recognition and reaction time data suggested that old adults' activation of target material is similar to young adults, but they experience sustained activation of irrelevant material that has entered working memory. Theoretical implications of these findings for inhibitory deficit (R. T. Zacks & L. Hasher, 1998) and source memory deficit accounts of cognitive aging are discussed.     

Extraversion and reinforcement in verbal operant conditioning.

The present investigation was designed to study the relationship between extraversion and modes of reinforcement in verbal operant conditioning. A 4 X 3 randomized block design was replicated ten times. Eighty graduate and post-graduate male students were individually subjected to the standard Taffel conditioning procedure. When the numbers of conditioned responses produced by introverts and extraverts were compared, it was found that: (1) under negative reinforcement ('bad' and electric shock), with both the female and male experimenters, and under positive reinforcement ('good') with the male experimenter, the introverts' score was the higher of the two; (2) under positive reinforcement ('good') with the female experimenter, the extraverts' score was higher than that of the introverts.     

Some verbal behavior about verbal behavior

Beginning with behavior analysts' tendency to characterize verbal behavior as "mere" verbal behavior, the author reviews his own attempt to employ it to influence both his staff and policies of our government. He then describes its role in psychopathology, its effect on speakers in healing themselves and on engendering creativity. The paper ends by calling to our attention the role of verbal behavior in the construction of behavior analysis.     

Identifying emergent leaders from verbal and nonverbal communications.

Subject/observers were accurate in identifying emergent leadership hierarchies on four leadership dimensions when provided records of target groups' meetings containing only verbal communications, only nonverbal communications, or both types of behavior. With knowledge of participation rates controlled by covariance, the subject/observers' accuracy scores retained significance in three of the information conditions demonstrating the presence of verbal and nonverbal leadership cues independent of participation rates. The value of verbal and nonverbal communications to identifying leaders varied with the type of leadership hierarchy being identified. The findings are presumed to hold for leader selection as well. The author proposes that the question of why a group member has emerged to fulfill a leadership role in a group be studied from the point of view of group members' selecting leaders or permitting emergence rather than leaders emitting behaviors.     

Attention-switching and grouping in counting interaurally presented clicks.

The present study tests the hypothesis that attention-switching is time-consuming and performance-limiting. Analysis of previous research on counting interaurally presented clicks shows that estimates of ‘switch-times’ can be made, based on the data of Guzy and Axelrod (1972). In the earlier click-counting studies, however, the number of clicks to be counted and the number of physical switches between the ears were confouned. Hence the number of clicks, number of physical switches and interval between clicks were independently varied. The results showed that (a) counting performance did not decrease monotonically with increasing number of switches in the click sequence; (b) no difference in counting performance could be found between the monaural and completely alternating interaural presentation; (c) when the number of switches in the sequence was small and equal groups of clicks alternated between ears, performance dramatically improved. With these kinds of sequences, subjects presumably do not count the clicks one at a time, but subitize a group of clicks.     

Dot counting by brain damaged subjects.

In this study, we examine how brain damaged adults (aphasics, right-brain lesioned subjects (RBD), and demented subjects) perform a basic education skill: determining the cardinality of different sets of objects (dots). The RBD subjects encountered more difficulty with the spatial correspondence components of the task (correct pointing to the dots), while the aphasics experienced more difficulty with the verbal components (the production of the correct number-word sequence). The deficit evidenced by the demented patients was less systematic. However, qualitative analyses of patients' behavior suggested an organization that tended to minimize the impact of their cognitive deficits on the object-counting task, and an analysis of their counting indicates that the basic counting principles proposed by Gelman (1982) and Fuson (1988) may be preserved.     

Effects of verbal imitation and comprehension training on verbal production

This study sought to determine whether some combination of imitation training and comprehension training was necessary to achieve verbal production or whether comprehension training alone was sufficient to result in verbal production. Fifty-one first- and second-grade subjects were trained to imitate eight words (Spanish nouns) for which there were no referents. An additional set of eight words was trained in a comprehension task where overt verbal rehearsal was prohibited. Once criterion of two successive sessions of 100% performance was reached in training for both imitation and comprehension, training modes were reversed so that items initially trained in imitation were then trained in comprehension andvice versa. Results showed that initial comprehension training did result in some verbal production, whereas initial imitation training, as expected, did not. A marked improvement in verbal production performance was observed when initial comprehension training was followed by imitation training. When initial imitation training was followed by comprehension training, verbal production also resulted but not to the degree or with the consistency of performance which marked the comprehension-then-imitation sequence. Furthermore, comprehension training required more trials to reach a similar level of proficiency when it followed imitation training than when it preceded imitation. These data indicate that initial imitation training interferes with acquisition of subsequent comprehension and production responses and that the preferred training sequence is one which initially focuses on comprehension and follows this with verbal imitation.This study was supported by Grant HD 00870 from the National Institute of Child Health and Human Development and Grant NS 10468 from the National Institute of Neurological Diseases and Stroke awarded to the Bureau of Child Research, University of Kansas, Lawrence, Kansas.