Numerical abstraction by human infants

Across several experiments, 6- to 8-month-old human infants were found to detect numerical correspondences between sets of entities presented in different sensory modalities and bearing no natural relation to one another. At the basis of this ability, we argue, is a sensitivity to numerosity, an abstract property of collections of objects and events. Our findings provide evidence that the emergence of the earliest numerical abilities does not depend upon the development of language or complex actions, or upon cultural experience with number.     

Event representation in Pavlovian conditioning: image and action

In a typical Pavlovian conditioning experiment, a relatively insignificant event, the conditioned stimulus (CS), is paired with a biologically more meaningful event, the unconditioned stimulus (US). As a consequence of those pairings, the CS is thought to acquire response characteristics of the US. In this article I describe experiments with rats that suggest that under some circumstances, the CS acquires control of perceptual processing of the US, in the absence of that US itself. I present three kinds of evidence for this surrogate processing, which I liken to imagery or hallucination: (1) CSs come to control specific, sensory-evaluative responses normally evoked only by the USs; (2) CSs can substitute for USs in the establishment of new learning about those USs themselves; (3) CSs can substitute for USs in the modulation of conditioning to other events, either overshadowing (interfering) or potentiating learning, in the same manner as the USs themselves. Finally, I compare these data with evidence for conditioned sensation and imagery in humans, and suggest that imagery may be a very basic process, evolutionarily derived from perceptual and conditioning processes adapted to deal with remote or absent objects.     

Literalism as a marker of hypnotic "trance": disconfirming evidence

The responses given by highly hypnotizable, hypnotic subjects and those of unhypnotizable subjects who simulated hypnosis to questions of the type, "Do you mind telling me your name?" and "Do you mind standing up?" were contrasted. The purpose was to examine Erickson's (1980) assertion that literalism (answering "yes" or "no" verbally or nonverbally without any cognitive elaboration) is a marker of hypnotic "trance." Simulators exhibited a greater rate of literalism than hypnotic "virtuosos" (i.e., extreme scorers on both group and individual hypnotizability measures). Hypnotized subjects and nonhypnotized subjects approached in the campus library responded comparably. Because less than a third of hypnotic virtuosos responded literally, our results strongly refuted Erickson's assertion that literalism is a cognitive feature of hypnosis.     

Selective processing of threat cues in posttraumatic stress disorder

Vietnam combat veterans with (n = 15) and without (n = 15) posttraumatic stress disorder (PTSD) performed a modified Stroop task in which they named the colors of neutral words (e.g., INPUT), positive words (e.g., LOVE), obsessive-compulsive disorder (OCD) words (e.g., GERMS), and PTSD words (e.g., BODYBAGS). In contrast to normal controls, PTSD patients took significantly longer to color-name PTSD words than to color-name neutral, OCD, and positive words. Because Stroop interference reflects involuntary semantic activation, it may provide a quantitative measure of intrusive cognitive activity--the hallmark symptom of PTSD.     

Reasons for Living Following Success and Failure in Suicidal and Nonsuicidal College Students1

To see if suicide ideators responded differently than nonideators after success or failure experiences, 61 college students who were relatively high or low ideators participated in a computer task on which half got bogus success feedback, the other half got bogus failure feedback. Both groups then completed the Reasons for Living Inventory (RFL). Two (High versus Low Suicide) X 2 (Success or Failure) analyses indicated main effects for suicide on overall RFL and four of the six RFL subscales. Although there were no main effects for success versus failure, an interaction indicated that, in the failure condition, low suicidal subjects were significantly higher than high suicidal subjects in overall reasons for living. Results suggest that suicidal individuals may be vulnerable to failure, and may need interventions to help them avoid potential failure or to bolster their coping mechanisms.     

Children's understanding of private keys in referential communication

A private key is a referential utterance used to inform selectively. The ambiguity of the utterance conceals meaning from nonselected audience members. The purpose of this study was to examine three aspects of children's understanding of the use of private keys. Experiment 1 concerned children's sensitivity to information in the context of utterance (i.e., the common ground). Experiment 2 examined appreciation of audience design and the speaker's intent. Experiments 3, 4, and 5 explored some reasons for children's problems in understanding private keys. The results show that even first graders are sensitive to common ground information and the speaker's intent. However, audience design is troublesome even for second graders in some situations, probably because they fail to assess the knowledge of the audience members. Private keys are important theoretically because they represent an aspect of referential communication involving the uses of ambiguous utterances that have been ignored by developmental researchers.     

When do children overestimate their knowledge of unfamiliar targets?

We report four investigations in which 5 to 7 year olds judged whether or not they knew familiar- and unfamiliar-named targets. Under some conditions judgments were made in relation to performance on a relevant task, e.g., children judged whether they knew the picture they had picked from a set was the target. Under other conditions, children judged their state of knowledge not in relation to performance, e.g., they answered "Do you know who (target) is?" Under both types of condition, children nearly always made correct "know" judgments when targets were familiar. Correct "don't know" judgments about unfamiliar targets were relatively common when judgments were not made in relation to performance on a task (average scores 80-90% correct), but were less frequent when knowledge was judged in relation to performance on a task (average scores 40-70% correct). Knowledge judged in relation to performance was overestimated even when children did not choose the picture they thought might be the target before making their judgment, when the pictures were face-down, and when children predicted performance on a task not yet present. It seems that although children can make relatively accurate judgments of their own knowledge states, they tend to overestimate their competence when assessing their knowledge in relation to performance on a task. We discuss why this might be.     

Marked sex differences on a fine motor skill task disappear when finger size is used as covariate

Purdue Pegboard performance of 16 male and 25 female right-handed college students were compared, and results were replicated with 25 male and 28 female subjects. In agreement with the literature, women performed significantly better than men. When measures of index finger and thumb thickness were used as covariate, all significant sex differences in performance disappeared. Negative correlations between performance and finger size were observed in both sexes. Sex differences in fine manual dexterity tasks may therefore be confounded by sex differences in finger size.     

Assessing individual differences in proneness to shame and guilt: development of the Self-Conscious Affect and Attribution Inventory

Individual differences in proneness to shame and proneness to guilt are thought to play an important role in the development of both adaptive and maladaptive interpersonal and intrapersonal processes. But little empirical research has addressed these issues, largely because no reliable, valid measure has been available to researchers interested in differentiating proneness to shame from proneness to guilt. The Self-Conscious Affect and Attribution Inventory (SCAAI) was developed to assess characteristic affective, cognitive, and behavioral responses associated with shame and guilt among a young adult population. The SCAAI also includes indices of externalization of cause or blame, detachment/unconcern, pride in self, and pride in behavior. Data from 3 independent studies of college students and 1 study of noncollege adults provide support for the reliability of the main SCAAI subscales. Moreover, the pattern of relations among the SCAAI subscales and the relation of SCAAI subscales to 2 extant measures of shame and guilt support the validity of this new measure. The SCAAI appears to provide related but functionally distinct indices of proneness to shame and guilt in a way that these previous measures have not.