Metacognition in monkeys during an oculomotor task

This study investigated whether rhesus monkeys show evidence of metacognition in a reduced, visual oculomotor task that is particularly suitable for use in fMRI and electrophysiology. The 2-stage task involved punctate visual stimulation and saccadic eye movement responses. In each trial, monkeys made a decision and then made a bet. To earn maximum reward, they had to monitor their decision and use that information to bet advantageously. Two monkeys learned to base their bets on their decisions within a few weeks. We implemented an operational definition of metacognitive behavior that relied on trial-by-trial analyses and signal detection theory. Both monkeys exhibited metacognition according to these quantitative criteria. Neither external visual cues nor potential reaction time cues explained the betting behavior; the animals seemed to rely exclusively on internal traces of their decisions. We documented the learning process of one monkey. During a 10-session transition phase, betting switched from random to a decision-based strategy. The results reinforce previous findings of metacognitive ability in monkeys and may facilitate the neurophysiological investigation of metacognitive functions.     

Small samples do not cause greater accuracy--but clear data may cause small samples: comment on Fiedler and Kareev (2006)

Fiedler and Kareev (2006) have claimed that taking a small sample of information (as opposed to a large one) can, in certain specific situations, lead to greater accuracy--beyond that gained by avoiding fatigue or overload. Specifically, they have argued that the propensity of small samples to provide more extreme evidence is sufficient to create an accuracy advantage in situations of high caution and uncertainty. However, a close examination of Fiedler and Kareev's experimental results does not reveal any strong reason to conclude that small samples can cause greater accuracy. We argue that the negative correlation between sample size and accuracy that they reported (found only for the second half of Experiment 1) is also consistent with mental fatigue and that their data in general are consistent with the causal structure opposite to the one they suggest: Rather than small samples causing clear data, early clear data may cause participants to stop sampling. More importantly, Experiment 2 provides unequivocal evidence that large samples result in greater accuracy; Fiedler and Kareev only found a small sample advantage here when they artificially reduced the data set. Finally, we examine the model that Fiedler and Kareev used; they surmised that decision makers operate with a fixed threshold independent of sample size. We discuss evidence for an alternative (better performing) model that incorporates a dynamic threshold that lowers with sample size. We conclude that there is no evidence currently to suggest that humans benefit from taking a small sample, other than as a tactic for avoiding fatigue, overload, and/or opportunity cost-that is, there is no accuracy advantage inherent to small samples.     

Behavioral responses to light by headless anesthetized Drosophila melanogaster

The bodies of decapitated fruit flies are known to retain a variety of functional sensory inputs, processing, and behavioral responses. Here I report a previously undescribed phenomenon: headless bodies can respond to a light presentation with movement, walking, and flight. Headless anesthetized flies also respond to a light presentation with behavior, albeit to a lesser degree. The mechanism underlying the behavioral response of headless flies to light might include extracephalic photoreceptors or thermoreceptors.     

Structural priming as structure-mapping: children use analogies from previous utterances to guide sentence production

What mechanisms underlie children’s language production? Structural priming—the repetition of sentence structure across utterances—is an important measure of the developing production system. We propose its mechanism in children is the same as may underlie analogical reasoning: structure‐mapping. Under this view, structural priming is the result of making an analogy between utterances, such that children map semantic and syntactic structure from previous to future utterances. Because the ability to map relationally complex structures develops with age, younger children are less successful than older children at mapping both semantic and syntactic relations. Consistent with this account, 4‐year‐old children showed priming only of semantic relations when surface similarity across utterances was limited, whereas 5‐year‐olds showed priming of both semantic and syntactic structure regardless of shared surface similarity. The priming of semantic structure without syntactic structure is uniquely predicted by the structure‐mapping account because others have interpreted structural priming as a reflection of developing syntactic knowledge.     

Stability of language in childhood: a multiage, multidomain, multimeasure, and multisource study

The stability of language across childhood is traditionally assessed by exploring longitudinal relations between individual language measures. However, language encompasses many domains and varies with different sources (child speech, parental report, experimenter assessment). This study evaluated individual variation in multiple age-appropriate measures of child language derived from multiple sources and stability between their latent variables in 192 young children across more than 2 years. Structural equation modeling demonstrated the loading of multiple measures of child language from different sources on single latent variables of language at ages 20 months and 48 months. A large stability coefficient (r = .84) obtained between the 2 language latent variables. This stability obtained even when accounting for family socioeconomic status, maternal verbal intelligence, education, speech, tendency to respond in a socially desirable fashion, and child social competence. Stability was also equivalent for children in diverse childcare situations and for girls and boys. Across age, from the beginning of language acquisition to just before school entry, aggregating multiple age-appropriate methods and measures at each age and multiple reporters, children show a strong stability of individual differences in general language development.     

Comparing measures of attachment: "To whom one turns in times of stress", parental warmth, and partner satisfaction

The Attachment and Clinical Issues Questionnaire (ACIQ; M. A. Lindberg & S. W. Thomas, 2011), was developed over an 18-year period containing 29 scales. The purpose of the present study was to test (a) the validity of the attachment scales in terms of how they predict to whom one turns in times of stress and for affective sharing, and (b) how the attachment scales compared with the Experiences in Close Relationship Questionnaire (ECR) in terms of concurrent, convergent, and discriminant evidence. The relevant secure scales of the ACIQ predicted to whom one turned in study 1, and study 2 demonstrated good convergent evidence with the ECR, but superior concurrent evidence in predicting partner satisfaction, and superior discriminant evidence in differentially correlating with mother and father warmth. Thus, the ACIQ passed essential validity and psychometric tests and was a more robust measure than the ECR with these defining characteristics of attachment.     

The effect of sonority on word segmentation: evidence for the use of a phonological universal

It has been well documented how language-specific cues may be used for word segmentation. Here, we investigate what role a language-independent phonological universal, the sonority sequencing principle (SSP), may also play. Participants were presented with an unsegmented speech stream with non-English word onsets that juxtaposed adherence to the SSP with transitional probabilities. Participants favored using the SSP in assessing word-hood, suggesting that the SSP represents a potentially powerful cue for word segmentation. To ensure the SSP influenced the segmentation process (i.e., during learning), we presented two additional groups of participants with either (a) no exposure to the stimuli prior to testing or (b) the same stimuli with pauses marking word breaks. The SSP did not influence test performance in either case, suggesting that the SSP is important for word segmentation during the learning process itself. Moreover, the fact that SSP-independent segmentation of the stimulus occurred (in the latter control condition) suggests that universals are best understood as biases rather than immutable constraints on learning.     

Recollection training and transfer effects in Alzheimer's disease: effectiveness of the repetition-lag procedure

Objective

This study was designed to extend the use of a memory training technique, known as the repetition-lag procedure, to Alzheimer patients. The specificity of this procedure is to target the process of recollection for improvement.

Method

A group of 12 patients were trained individually for 6 h. The training procedure consisted of a series of yes/no recognition tasks in which some words were repeated throughout the test list across gradually increasing delays. Their performance was evaluated on pre-and-post tests and compared with a recognition practice group and a no contact control group.

Results

Initially, recollection training patients only performed accurately when the delay between repetitions consisted of one intervening word, but by the end of training their performance increased up to four-word intervals. Interestingly, these benefits generalized to other measures of memory, such as working memory, visual memory and source recognition.

Conclusions

Effectiveness of the repetition-lag procedure in Alzheimer’s disease is discussed.     

Attentional factors in conceptual congruency

Conceptual congruency effects are biases induced by an irrelevant conceptual dimension of a task (e.g., location in vertical space) on the processing of another, relevant dimension (e.g., judging words' emotional evaluation). Such effects are a central empirical pillar for recent views about how the mind/brain represents concepts. In the present paper, we show how attentional cueing (both exogenous and endogenous) to each conceptual dimension succeeds in modifying both the manifestation and the symmetry of the effect. The theoretical implications of this finding are discussed.     

Family members' unique perspectives of the family: examining their scope, size, and relations to individual adjustment

Using the McMaster Family Assessment Device (Epstein, Baldwin, & Bishop, 1983) and incorporating the perspectives of adolescent, mother, and father, this study examined each family member's "unique perspective" or nonshared, idiosyncratic view of the family. We used a modified multitrait-multimethod confirmatory factor analysis that (a) isolated for each family member's 6 reports of family dysfunction the nonshared variance (a combination of variance idiosyncratic to the individual and measurement error) from variance shared by 1 or more family members and (b) extracted common variance across each family member's set of nonshared variances. The sample included 128 families from a U.S. East Coast metropolitan area. Each family member's unique perspective generalized across his or her different reports of family dysfunction and accounted for a sizable proportion of his or her own variance in reports of family dysfunction. In addition, after holding level of dysfunction constant across families and controlling for a family's shared variance (agreement regarding family dysfunction), each family member's unique perspective was associated with his or her own adjustment. Future applications and competing alternatives for what these "unique perspectives" reflect about the family are discussed.