The role of phonological and visual working memory in complex arithmetic for Chinese- and Canadian-educated adults

Two experiments were conducted to test cultural differences in the role of phonological and visual working memory in complex arithmetic. Canadian- and Chinese-educated students solved complex subtraction problems (e.g., 85 − 27; Experiment 1) and complex multiplication problems (e.g., 6 − 13; Experiment 2) under phonological and visual working memory loads. Problem complexity (i.e., borrow or carry operations) and presentation format (i.e., horizontal vs. vertical) were also manipulated. The results showed that both Chinese- and Canadian-educated participants relied on both phonological and visual working memory resources when solving complex subtraction and multiplication problems. Selective involvement of phonological and visual working memory as a function of operation (Lee & Kang, 2002) or presentation format (Trbovich & LeFev re, 2003) was found only for Chinese-educated participants and not for Canadian-educated participants, calling into question the generalizability of these findings across arithmetic operations and cultural groups.     

Individual differences in the obligatory activation of addition facts

In two experiments, we found evidence for individual differences in the obligatory activation of addition facts. Subjects were required to verify the presence of a target digit (e. g., 4) in a previously presented pair (e. g., 5 + 4). Subjects rejected targets that formed the sum of the initial pair (e. g., 5+4 and 9) more slowly than they rejected unrelated targets (e. g., 5+4 and 7). This interference of the sum was largest for subjects who were relatively skilled at multidigit arithmetic. Less skilled subjects did not show statistically significant effects of obligatory activation. In comparison with less skilled subjects, skilled subjects showed differential interference on plus-one (e. g., 34 1) and standard (e. g, 2+3) problems when the plus sign was presented, and on ties (e. g., 22) when the plus sign was omitted. These results suggest that network models of arithmetic fact retrieval are appropriate for skilled subjects, but that alternative models need to be considered for less skilled individuals.     

Interpretation of instructions: A source of individual differences in analogical reasoning

Two studies were conducted to identify individual differences in the effect of instruction on strategies used to solve figural/numerical analogies. In Study 1, students aged 9, 11, 13, and 19 years were given incomplete instructions and then were assessed for (a) consistent use of an appropriate rule for solving analogies and (b) the type and number of stimulus attributes that are incorporated in those analogical rules. Use of an analogical rule increased with age and corresponded to higher scores on a psychometric test of reasoning within each age group. In Study 2, analysis of verbal protocols was used to identify the strategies of some 9- and 11-year-olds who showed a peculiar pattern of responding in Study 1. These children attended to relevant attributes but used systematic nonanalogical rules to solve problems. When provided with more specific instructions, most of these children adopted an analogical rule but failed to incorporate relevant attributes. Results indicate that selection or construction of task-relevant solution strategies from incomplete instructions may partially account for differential performance on tests of analogical reasoning.     

More on the relation between division and multiplication in simple arithmetic: Evidence for mediation of division solutions via multiplication

Adults (N = 32) solved simple multiplication (e.g., 8 x 7) and corresponding division problems (e.g., 56/8). Self-reports of solution processes were given by half of the participants. Latency patterns and error rates were closely related across operations and were similar in self-report and no-report conditions. Solution of division problems, however, facilitated solution of multiplication problems more than the reverse. On large division problems, participants reported that they "recast" problems as multiplication (e.g., 56/8 as 8 x = 56). These results support the hypothesis that multiplication and division are stored in separate mental representations but that solution of difficult division problems sometimes involves access to multiplication.     

Automated psychophysiology laboratory

A laboratory has recently been established in University Hospital based on a PDP-11 /40 processor running a real-time Executive (RSX-ll/D) which has storage and data acquisition peripherals to handle on-line processing of psychophysiological data from patients receiving biofeedback. A data acquisition program has been written which permits the sampling of eight simultaneous channels of data coming from a Hewlett-Packard 7700 electrophysiological recorder system. Input from the patient includes switch closures and variable resistors, thermistors, GSR, electrocardiogram, respiration rate, and a variety of others. Feedback to the patient includes a variety of types of lights, a cathode ray tube storage screen, a character-oriented CRT monitor, and a variety of audio signals. Developers are presently involved in writing the biofeedback section of the programs and an on-line decision-making dependent upon patient response. Simultaneously with laboratory operation, a number of other users are served. These include the Admitting Department and Respiratory Function Laboratory. A rat laboratory will be served also by this facility in the near future via a front-end microprocessor.     

Impulsivity in adults: motor inhibition and time-interval estimation

There is a need for the development of behavioral measures of impusivity in order to elucidate the specific qualities of impulsive persons. The relationships between two behavioral measures of impulsivity and several personality inventories frequently used to assess inpulsivity were examined using 40 male Ss. The behavioral measures involved a motor-inhibition (MI) task and time-interval (TI) estimation. The personality measures included the Extraversion (E), Psychoticism (P) and Neuroticism (N) scales of the Eysenck Personality Questionnaire (EPQ), Barrat's Impulsivity Scale (BIS) and Gough's Socialization Scale (So). Significant relationships between MI scores and E, BIS and a proposed dimension of impulsivity obtained by the formation of E-P quadrants were found. In addition, performance on this task was related to So, P and E-N quadrants in the predicted directions. The consistency of these results supports the use of this task as a behavioral measure of impusivity in adults. Although personality inventory scores were not related to estimations, significant (negative) correlations were obtained between TI estimations and MI scores. The results indicate that TI estimation by itself is not an adequate measure of impulsivity, but does have implications for understanding impulsive behavior.     

News Coverage of Intimate Partner Violence: Impact on Prosocial Responses

Intimate partner violence (IPV) is a pervasive and widespread problem in the United States, yet the issue is not well understood among the general public. Media portrayals of IPV have a significant influence on public perceptions, including public support for IPV victims and willingness to engage in helping behaviors. In the current study, we tested a path model examining the influence of contextual information about the victim and perpetrator described in a news article on feelings of sympathy for the victim of the described IPV incident, affective perspective taking, and prosocial responses that include: (a) support for public health initiatives to help victims of IPV, (b) preferences for prosocial information seeking, and (c) behavioral intentions toward engaging in protective actions to help victims of IPV. The model demonstrated acceptable fit and provided support for all 6 hypotheses. Results showed that sympathy does not have a direct impact on individuals' prosocial responses to help victims of IPV, but instead has an indirect effect through affective perspective taking. Implications for framing IPV in ways that promote a prosocial, public health–oriented response are discussed.     

The Relationship Between Balance Confidence and Cognitive Motor Interference in Individuals With Multiple Sclerosis

The authors examined and compared the development of oral and manual force control in preschool-aged children. In all, 50 typically developing children (aged 3-5 years) performed maximal strength tasks and submaximal visually guided tasks using tongue elevation, power, and precision grips. Dependent measures included strength, rate of force rise, initial force overshoot, force variability, and rate of force release. The authors performed age- and performance-related analyses. Results revealed similar changes for tongue, fingers, and hands across age- and performance-related measures for strength, initial force overshoot, and rate of force release. There were no significant changes in rate of force rise with increasing age. Force variability measures showed effector-specific changes with decreases across age- and performance-related measures for the hands and fingers but not for the tongue. Changes common across effector systems likely reflect biological development coupled with cognitive-strategic development. Effector-specific changes in force variability likely reflect experience gained through functional tasks influencing biological and cognitive-strategic development. Lack of change in force variability of the tongue suggests that fine control of the tongue is activity specific; thus, nonfunctional tasks are not likely to be sensitive to experience-related biological development.     

Knowledge of counting principles: How relevant is order irrelevance?

Most children who are older than 6 years of age apply essential counting principles when they enumerate a set of objects. Essential principles include (a) one-to-one correspondence between items and count words, (b) stable order of the count words, and (c) cardinality—that the last number refers to numerosity. We found that the acquisition of a fourth principle, that the order in which items are counted is irrelevant, follows a different trajectory. The majority of 5- to 11-year-olds indicated that the order in which objects were counted was relevant, favoring a left-to-right, top-to-bottom order of counting. Only some 10- and 11-year-olds applied the principle of order irrelevance, and this knowledge was unrelated to their numeration skill. We conclude that the order irrelevance principle might not play an important role in the development of children’s conceptual knowledge of counting.