Inferences from memory: strategy- and exemplar-based judgment models compared

What are the cognitive processes underlying people's inferences from memory? To provide an answer, the exemplar-based approach to predicting people's inferences is tested against the strategy-based approach. Exemplar models assume that people make inferences about objects by retrieving similar objects from memory. In contrast, the strategy-based approach assumes that people select cognitive strategies that make inferences based on abstracted knowledge and information the inference situation provides. In Experiment 1, in which dichotomous feedback on the level of pair-comparisons was provided, almost all participants were classified as using a simple lexicographic strategy. In Experiment 2, in which continuous feedback for single objects was provided, most participants were classified as using a compensatory strategy. Both experiments suggest that the strategy-based approach is more suitable for predicting people's inferences from memory than the exemplar-based approach. The strategy-based approach shows how people adapt to inference situations by selecting different cognitive strategies.     

Emotionally controlled decision-making and a gene variant related to serotonin synthesis in women with borderline personality disorder

The Iowa Gambling Task (IGT) was used to examine (i) social decision-making in women with borderline personality disorder (BPD), and (ii) the relationship between impaired decision-making and the tryptophan hydroxylase-1 (TPH-1) gene, involved in serotonin synthesis. Forty-two women with BPD and a history of suicide attempts were genotyped, and the frequency of a TPH-1 haplotype previously uniquely associated with BPD was calculated. The BPD group scored significantly lower than a control group in the IGT. Furthermore, the TPH-1 haplotype displayed a significantly higher frequency in BPD participants with impaired decision making, compared to BPD participants with normal scores. These findings suggest that impaired decision-making as determined by the IGT is a feature of BPD and may be (i) associated with serotonin dysfunction, and (ii) possibly relevant for suicidal behavior.     

Brain dynamics of word familiarization in 20-month-olds: effects of productive vocabulary size

The present study investigated the brain mechanisms involved during young children's receptive familiarization with new words, and whether the dynamics of these mechanisms are related to the child's productive vocabulary size. To this end, we recorded event-related potentials (ERPs) from 20-month-old children in a pseudoword repetition task. Results revealed distinct patterns of repetition effects for children with large and small productive vocabularies. High producers showed evidence of recognizing the novel words already after three presentations, while the low producers needed five presentations to display a recognition effect. The familiarization process was manifested in the modulations of two components, the N200-400 and a later fronto-central component, which appeared to increase in amplitude until a certain level of encoding was reached and then decrease with further repetition. These findings suggest a relation between the onset of the productive vocabulary spurt and the rate of receptive word familiarization.     

Separating ability from need: clarifying the dimensional structure of the Need for Closure Scale

The validity of the Need for Closure Scale (NFCS) has recently been debated in the research literature. In the present study, it is argued that the traditional Decisiveness scale primarily taps ability content instead of the hypothesized motivational need; therefore, new items that explicitly probe the need for quick and unambiguous answers were developed. It was shown that these need items form a reliable scale (Study 1); were predictive of the seizing process over and beyond ability, whereas the old Decisiveness scale was not (Study 2); and were sensitive to experimentally manipulated levels of task motivation (Study 3). Finally, a reassembled NFCS with the new items replacing the traditional Decisiveness items showed superior fit as a unidimensional model. In the Discussion, it is argued that the specific position of Decisiveness is due to its particular operationalization, not to its theoretical status.     

Formal Schooling Influences Two- but Not Three-Dimensional Naming Skills

The modulatory influence of literacy on the cognitive system of the human brain has been indicated in behavioral, neuroanatomic, and functional neuroimaging studies. In this study we explored the functional consequences of formal education and the acquisition of an alphabetic written language on two- and three-dimensional visual naming. The results show that illiterate subjects perform significantly worse on immediate naming of two-dimensional representations of common everyday objects compared to literate subjects, both in terms of accuracy and reaction times. In contrast, there was no significant difference when the subjects named the corresponding real objects. The results suggest that formal education and learning to read and to write modulate the cognitive process involved in processing two- but not three-dimensional representations of common everyday objects. Both the results of the reaction time and the error pattern analyses can be interpreted as indicating that the major influence of literacy affects the visual system or the interaction between the visual and the language systems. We suggest that the visual system in a wide sense and/or the interface between the visual and the language system are differently formatted in literate and illiterate subjects. In other words, we hypothesize that the pattern of interactions in the functional-anatomical networks subserving visual naming, that is, the interactions within and between the visual and language processing networks, differ in literate and illiterate subjects.     

Decomposing coronary-prone behavior: Dimensions of type a behavior in the Videotaped Structured Interview

This study examined the factorial structure of data generated in the Videotaped Structured Interview for assessment of Type A behavior. Based on the literature, it was argued that there are at least three distinct concepts of Type A behavior, focused on competitiveness and pressured drive, speech characteristics, and hostility, respectively. These three concepts were clearly represented among the factors from factor analyses based on data from 282 subjects. Three factors represented speech and psychomotor characteristics, where the first reflected interactions between subject and interviewer (e.g., response latency, interruptions), the second tempo of speech (accelerating, dysrhythmic and rapid speech), and the third oral gestures (e.g., expiratory sighs). Hostility was reflected in two factors, one defined by emotional intensity (e.g., anger when recalling paat event) and the other hostility expressed towards the interviewer. Pressured drive dominated a content factor reflecting self-awareness of Type A behavior. Finally, there was one factor related to psychomotor tension. Through further factor and item analyses, it was possible to combine these factors into three homogeneous and moderately intercorrelated subscales of Type A behavior reflecting Hostility, Speech Characteristics, and Self-Awareness of Type A behavior. These scales showed good interrater agreement and stability over two years. The Self-Awareness Scale was highly correlated with self-report measures of Type A behavior. The Hostility Scale, on the other hand, was moderately related to measures of Type A behavior, anger and hostility, but was unrelated to anxiety. The Speech Characteristic Scale, finally, was virtually unrelated to psychometric measures.     

Childhood amnesia and distinctions between forms of memory: A comment on Wood, Brown, and Felton

Recently, Wood and his colleagues (1989) presented a case of childhood amnesia as evidence against the distinction between declarative and procedural memory that has sometimes been applied to human amnesia. Their argument was based on the observation that their patient showed some progress in school over the years, i.e., acquired some declarative knowledge, despite severely impaired day-to-day memory ability. We briefly review their case, together with a carefully studied second case of childhood amnesia not mentioned by Wood et al. Their argument is wrong in several ways. First, the utility of the declarative/procedural distinction for amnesia, or the utility of any other distinction between memory systems, depends on whether or not one kind of memory is impaired selectively, not on the severity of the impairment. In particular there is no requirement that one kind of memory be totally absent. Second, they have not provided the data necessary to support their argument; namely, data showing that the amount of declarative knowledge accumulated during years in school was better than would have been expected given the capacity for moment-to-moment or day-to-day memory. Indeed, the patient's moment-to-moment memory ability is better than represented, and the patient's progress in school was abnormally slow. Third, it is not clear that academic achievement scores provide a direct measure of declarative memory abilities (skill learning and recovery of function may also have contributed). We conclude that the evidence from childhood amnesia is fully consistent with the proposal that amnesia reflects a selective impairment in the formation of long-term declarative memory.     

Matrix differential calculus with applications to simple,hadamard, and kronecker products

Several definitions are in use for the derivative of an m × p matrix function F(X) with respect to its n × q matrix argument X. We argue that only one of these definitions is a viable one, and that to study smooth maps from the space of n × q matrices to the space of m × p matrices it is often more convenient to study the map from nq-space to mp-space. Also, several procedures exist for a calculus of functions of matrices. It is argued that the procedure based on differentials is superior to other methods of differentiation, and leads inter alia to a satisfactory chain rule for matrix functions.