Decision making with the "adaptive toolbox": influence of environmental structure,intelligence, and working memory load

In 2 experiments with a total of 220 participants, the tendency to use simple heuristics such as the take the best heuristic in an adaptive manner was investigated. In a simulated stock market paradigm, the payoff structure of environments was varied, favoring either compensatory or noncompensatory decision strategies in terms of expected long-term payoff. In both experiments, the majority of participants were classified as using strategies that were adequate for the environment, supporting the notion of adaptive strategy selection. These strategy shifts were moderated by intelligence, as measured with common tests. Neither an additional learning phase (Experiment 1) nor working memory load or working memory capacity (Experiment 2) had additional effects on strategy selection.     

Midazolam amnesia and retrieval from semantic memory: Developing methods to test theories of implicit memory

Studies of organic anterograde amnesia have been central to the development of theories of implicit memory. Pharmacological amnesia provides an additional method for exploring implicit memory, allowing for the experimental manipulation of amnesia and the testing of more participants. A significant concern with pharmacological amnesia is whether its cognitive effects are specific to explicit memory. The current research examines the effects of the benzodiazepine, midazolam, on retrieval from semantic memory and encoding in explicit memory. We focus on midazolam because it holds significant advantages over other benzodiazepines in inducing pharmacological amnesia and prior research suggests it may be useful for testing theories of implicit memory. Our results demonstrate that midazolam does not impair accuracy of retrieval from semantic categories, even when it produces anterograde amnesia for retrieved category items on a later recall test. These results suggest ways midazolam can be used to help test theories of implicit memory.     

Adaptive flexibility and maladaptive routines in selecting fast and frugal decision strategies

Decision routines unburden the cognitive capacity of the decision maker. In changing environments, however, routines may become maladaptive. In 2 experiments with a hypothetical stock market game (n = 241), the authors tested whether decision routines tend to persist at the level of decision strategies rather than at the level of options in strategy selection. The payoff structure of the task was changed after 80 decision trials, rendering a new strategy optimal with respect to expected payoff. Whereas most participants detected the appropriate strategy at the beginning of the task, they tended to retain it even when it was no longer optimal. A hint about a possible change had only a small influence on this maladaptive routine; a monetary incentive had none. Switching to a similar but not identical task relaxed the routine, but not much.     

Less is more: executive function and symbolic representation in preschool children

Executive function is recognized as a critical component of children's cognitive and social development. In two studies, a measure of executive function that had been used in research with chimpanzees was adapted for preschoolers. On this task, called Less Is More, children must point to a smaller reward (two candies) to receive a larger reward (five candies). In Study 1 (N= 101), performance was significantly related to age (3 vs. 4), verbal ability, and established measures of executive function. In Study 2 (N= 128), symbolic representations substituted for real candies in this task. Three-year-olds' performance improved significantly as a function of symbolic distancing. This research has implications for the role of symbol systems in the development of executive control over thought and action.     

Callous–Unemotional Traits in Predicting the Severity and Stability of Conduct Problems and Delinquency

The current study tests whether the presence of callous–unemotional (CU) traits designates a group of children with conduct problems who show an especially severe and chronic pattern of conduct problems and delinquency. Ninety-eight children who were selected from a large community screening of school children in grades 3, 4, 6 and 7 were followed across four yearly assessments. Children with conduct problems who also showed CU traits exhibited the highest rates of conduct problems, self-reported delinquency, and police contacts across the four years of the study. In fact, this group accounted for at least half of all of the police contacts reported in the sample across the last three waves of data collection. In contrast, children with conduct problems who did not show CU traits continued to show higher rates of conduct problems across the follow-up assessments compared to non-conduct problem children. However, they did not show higher rates of self-reported delinquency than non-conduct problem children. In fact, the second highest rate of self-reported delinquency in the sample was found for the group of children who were high on CU traits but without conduct problems at the start of the study.     

Calculation,culture, and the repeated operand effect

A basic phenomenon of cognitive arithmetic is that problems composed of a repeated operand, so-called "ties" (e.g. 6+6, 7 x 7), typically are solved more quickly and accurately than comparable non-tie problems (e.g. 6+5, 7 x 8). In Experiment 1, we present evidence that the tie effect is due to more efficient memory for ties than for non-ties, which participants reported solving more often using calculation strategies. The memory/strategy hypothesis accounts for differences in the tie effect as a function of culture (Asian Chinese vs. non-Asian Canadian university students), operation (addition, multiplication, subtraction, and division), and problem size (numerically small vs. large problems). Nonetheless, Blankenberger (Cognition 82 (2001) B15) eliminated the tie response time (RT) advantage by presenting problems in mixed formats (e.g. 4 x four), which suggests that the tie effect with homogenous formats (4 x 4 or four x four) is due to encoding. In Experiment 2, using simple multiplication problems, we replicated elimination of the tie effect with mixed formats, but also demonstrated an interference effect for mixed-format ties that slowed RTs and increased errors relative to non-tie problems. Additionally, practicing non-tie problems in both orders (e.g. 3 x 4 and 4 x 3) each time ties were tested once (cf. Cognition 82 (2001) B15) reduced the tie effect. The format-mismatch effect on ties, combined with a reduced tie advantage because of extra practice of non-ties, eliminated the tie effect. Rather than an encoding advantage, the results indicate that memory access for ties was better than for non-ties.     

A two-stage model for visual-auditory interaction in saccadic latencies

In two experiments, saccadic response time (SRT) for eye movements toward visual target stimuli at different horizontal positions was measured under simultaneous or near-simultaneous presentation of an auditory nontarget (distractor). The horizontal position of the auditory signal was varied, using a virtual auditory environment setup. Mean SRT to a visual target increased with distance to the auditory nontarget and with delay of the onset of the auditory signal relative to the onset of the visual stimulus. A stochastic model is presented that distinguishes a peripheral processing stage with separate parallel activation by visual and auditory information from a central processing stage at which intersensory integration takes place. Two model versions differing with respect to the role of the auditory distractors are tested against the SRT data.     

Effortful Control in “Hot” and “Cool” Tasks Differentially Predicts Children’s Behavior Problems and Academic Performance

Effortful control (EC), the capacity to deliberately suppress a dominant response and perform a subdominant response, rapidly developing in toddler and preschool age, has been shown to be a robust predictor of children’s adjustment. Not settled, however, is whether a view of EC as a heterogeneous rather than unidimensional construct may offer advantages in the context of predicting diverse developmental outcomes. This study focused on the potential distinction between “hot” EC function (delay-of-gratification tasks that called for suppressing an emotionally charged response) and more abstract “cool” EC functions (motor inhibition tasks, suppressing-initiating response or Go-No Go tasks, and effortful attention or Stroop-like tasks). Children (N?=?100) were observed performing EC tasks at 38 and 52 months. Mothers, fathers, and teachers rated children’s behavior problems and academic performance at 67, 80, and 100 months, and children participated in a clinical interview at 100 months. Structural Equation Modeling (SEM) analyses with latent variables produced consistent findings across all informants: Children’s scores in “hot” EC tasks, presumably engaging emotion regulation skills, predicted behavior problems but not academic performance, whereas their scores in “cool” EC tasks, specifically those engaging effortful attention, predicted academic performance but not behavior problems. The models of EC as a heterogeneous construct offered some advantages over the unidimensional models. Methodological and clinical implications of the findings are discussed.     

Personality traits in people with synaesthesia: Do synaesthetes have an atypical personality profile?

People with synaesthesia not only have – by definition – unusual experiences (e.g., numbers triggering colour), they also have a different cognitive profile (e.g., in terms of their memory and perceptual abilities) and a bias towards certain interests and activities (e.g., towards the arts). However, virtually nothing is known about whether synaesthetes have an atypical personality profile. In this study, a standard measure of personality was administered (Big Five Inventory) along with two questionnaire measures of empathy. Synaesthetes, relative to demographically matched controls, reported higher levels of ‘Openness to Experience’ which is known to be related to imagination and artistic tendencies. They also reported higher levels of ‘Fantasizing’ on one of the empathy measures, which is conceptually related to Openness, although their self-reported empathy did not differ in other respects. In addition, synaesthetes reported lower levels of Agreeableness which we did not predict in advance.     

Parent–child interaction,task-oriented regulation,and cognitive development in toddlers facing developmental risks

The importance of supportive parent–child interactions and the development of regulatory abilities with regard to growth in children's cognitive abilities has been established. This study investigated the longitudinal relations among parental supportiveness, child task-oriented regulation, and cognitive development for low-income children facing developmental risks. Interlocking growth models were fit to these variables based on measurements made when the children were 14, 24, and 36 months of age. Results showed that growth rates of child cognition were related to baseline (14 months) parental supportiveness and changes in child task-oriented regulation. We additionally found that baseline levels of cognition were related to the baseline levels of child task-oriented regulation. This study suggests that both parental supportiveness during infancy and the concurrent development of child task-oriented regulation are related to cognitive development among children facing developmental risks.