Speed isn't everything: complex processing speed measures mask individual differences and developmental changes in executive control

The rate at which people process information appears to influence many aspects of cognition across the lifespan. However, many commonly accepted measures of ‘processing speed’ may require goal maintenance, manipulation of information in working memory, and decision‐making, blurring the distinction between processing speed and executive control and resulting in overestimation of processing speed contributions to cognition. This concern may apply particularly to studies of developmental change, as even seemingly simple processing speed measures may require executive processes to keep children and older adults on task. We report two new studies and a re‐analysis of a published study, testing predictions about how different processing speed measures influence conclusions about executive control across the lifespan. We find that the choice of processing speed measure affects the relationship observed between processing speed and executive control, in a manner that changes with age, and that choice of processing speed measure affects conclusions about development and the relationship among executive control measures. Implications for understanding processing speed, executive control, and their development are discussed.     

Confusable gratings selectively elicit orientation-contingent colour aftereffects

Induction of orientation-selective colour aftereffects (the McCollough effect) was studied with groups of young children who differed in their ability to discriminate an oblique grating from its mirror-image under recognition conditions. If the McCollough effect is generated through associative learning, children who failed to learn simple identifying responses to oblique lines as a function of the direction in which the lines point should also fail to associate colour lablels selectively to these same stimuli. Instead, the ease with which the McCollough effect was induced by alternate exposure to left-oblique lines in green light and right-oblique lines in red light was independent of the ability of the young child to discriminate direction of line under recognition conditions.     

Finding needles in haystacks: identity mismatch frequency and facial identity verification

Accurate person identification is central to all security, police, and judicial systems. A commonplace method to achieve this is to compare a photo-ID and the face of its purported owner. The critical aspect of this task is to spot cases in which these two instances of a face do not match. Studies of person identification show that these instances often go undetected when mismatches occur regularly in an experiment, but this differs from everyday operations in which identity mismatches are rare. The current study therefore examined whether infrequent identity mismatches are more likely to go undetected by observers. In Experiments 1 and 2, identity mismatches were detected equally under low (2%) and high (50%) mismatch prevalence. This pattern persisted when viewing conditions were optimized for person identification in Experiment 3, by using a card-sorting task in which all face identities could be viewed repeatedly, and also under increased task difficulty, by constraining viewing conditions temporally in Experiment 4. These results imply that the infrequent occurrence of identity mismatches in security settings such as passport control does not impair an observer's ability to detect these important events.     

A tool for tracking visual attention: The Restricted Focus Viewer

Eye-tracking equipment has proven useful in examining the cognitive processes people use when understanding and reasoning with visual stimuli. However, eye-tracking has several drawbacks: accurate eye-tracking equipment is expensive, it is often awkward for participants, it requires frequent recalibration, and the data can be difficult to interpret. We introduce an alternative tool: theRestricted Focus Viewer (RFV). This is a computer program that takes an image, blurs it, and displays it on a computer monitor, allowing the participant to see only a small region of the image in focus at any time. The region in focus can be moved using the computer mouse. The RFV records what the participant is focusing on at any point in time. It is cheap, nonintrusive, does not require calibration, and provides accurate data about which region is being focused on. We describe this tool and also provide experimental comparisons with eye-tracking. The RFV (Version 2.1) is freely available at http://www.csse.monash.edu. au/projects/RFV/.     

Perception of circular heading from optical flow

Observers viewed random-dot optical flow displays that simulated self-motion on a circular path and judged whether they would pass to the right or left of a target at 16 m. Two dots in two frames are theoretically sufficient to specify circular heading if the orientation of the rotation axis is known. Heading accuracies were better than 1.5 degrees with a ground surface, wall surface, and 3D cloud of dots, and were constant over densities down to 2 dots, consistent with the theory. However, there was an inverse relation between the radius of the observer's path and constant heading error, such that at small radii observers reported heading 3 degrees to the outside of the actual path with the ground and to the inside with the wall and cloud. This may be an artifact of a small display screen.     

A Brief,Hospital-Initiated Motivational Interviewing and Acceptance and Commitment Therapy Intervention to Link Postpartum Mothers Who Use Illicit Drugs With Treatment and Reproductive Care: A Case Report

Maternal substance use during the prenatal period often results in infants with compromised health outcomes. The American College of Obstetrics and Gynecology recommends screening, brief motivational interviewing, and referral to existing treatment for women who use illicit substances prenatally. However, many of these women do not present for prenatal care and are not identified as using substances until delivery of their infants, many of whom are admitted to the neonatal intensive care unit (ICU). We describe a case from a novel, hospital-initiated intervention study, Moms in ACTion (MIACT) that combines motivational interviewing (MI) and acceptance and commitment therapy (ACT) to target new mothers with an infant in the neonatal ICU who screen positive for illicit substance use prenatally or at delivery. The MIACT program consists of an adaptive intervention that includes up to three sessions. Initiation of substance use treatment and reproductive care via a gynecological visit are the primary targets of the intervention. Urine samples were collected at 2- and 6-month follow-up visits. The participant successfully completed the program, achieved both treatment outcomes, and had negative urine drug screens at follow-up visits. Improvements in readiness to change and psychological flexibility were also observed. The present case report of a new mother who used substances demonstrated feasibility for combining MI and ACT treatments and the potential for MIACT to increase treatment and contraception initiation, ultimately preventing future substance-exposed pregnancies.     

Information‐Theoretic Measures Predict the Human Judgment of Rhythm Complexity

To formalize the human judgment of rhythm complexity, we used five measures from information theory and algorithmic complexity to measure the complexity of 48 artificially generated rhythmic sequences. We compared these measurements to human prediction accuracy and easiness judgments obtained from a listening experiment, in which 32 participants guessed the last beat of each sequence. We also investigated the modulating effects of musical expertise and general pattern identification ability. Entropy rate and Kolmogorov complexity were correlated with prediction accuracy, and highly correlated with easiness judgments. A logistic regression showed main effects of musical training, entropy rate, and Kolmogorov complexity, and an interaction between musical training and both entropy rate and Kolmogorov complexity. These results indicate that information‐theoretic concepts capture some salient features of the human judgment of rhythm complexity, and they confirm the influence of musical expertise on complexity judgments.