Support for an explanation of the guidance effect in motor skill learning

The authors investigated whether the knowledge of results (KR) schedule influences the extent to which intrinsic feedback is noticed and used. Fifty-six participants received KR that was either delayed over 2 trials (Delay-2) or provided directly after each trial (Delay-0) during 160 trials of an unfamiliar aiming task. No-KR retention tests were given after 80 trials and 1 min and 24 hr after the end of acquisition. After retention, all participants were questioned about their use of intrinsic feedback during practice and whether those sources changed as a function of practice. The Delay-2 group performed significantly less accurately on the 1st and last blocks of acquisition trials but showed a significantly smaller performance decline from acquisition to retention. Moreover, the Delay-2 group noticed and used a greater variety of intrinsic feedback sources and its members were more likely to report that their usage changed with practice.     

Labor supply and consumption of food in a closed economy under a range of fixed- and random-ratio schedules: tests of unit price

The behavioral economic concept of unit price predicts that consumption and response output (labor supply) are determined by the unit price at which a good is available regardless of the value of the cost and benefit components of the unit price ratio. Experiment 1 assessed 4 pigeons' consumption and response output at a range of unit prices. In one condition, food was available according to a range of fixed-ratio schedules, whereas in the other condition, food was available according to a range of random-ratio schedules. Consistent with unit price predictions, consumption and response output were approximately equivalent across schedule types within the lower range of unit prices. However, at Unit Prices 64 (ratio value = 192) and greater, considerably more consumption and response output were observed in the random-ratio condition. Experiment 2 replicated these findings with 4 pigeons using the rapid demand curve assay procedure that is commonly used in the behavioral economics literature. Findings are integrated with two mathematical models of behavior under variable reinforcer delays.     

Distractor familiarity leads to more efficient visual search for complex stimuli

Previous reports suggest that distractor familiarity plays an important role in determining visual search efficiency. However, the specific tasks used in those studies limit the extension of their findings to real-world situations and everyday images. In the present study, subjects engaged in a prolonged period of search experience as a control of their level of familiarity with a large set of target and distractor images. Reaction times and search slopes decreased dramatically over this period, especially for trials with a large target eccentricity and many distractors. Following extended practice, search among familiar distractors was more efficient than search among unfamiliar distractors. Furthermore, we found that familiar targets were located more efficiently than unfamiliar targets and that subjects were faster at locating targets that they had experienced in the majority of the search trials. These results show that prolonged visual experience facilitates processing of both target and distractor items during search.     

Psychology of learning: a new approach to study behavior of Rhodnius prolixus stal under laboratory conditions

Conditioning methodologies associated with the psychology of learning are suggested as a new strategy to investigate behavior of the assassin bug Rhodnius prolixus, which is the main vector of Chagas disease in Venezuela. Chagas disease is the fourth leading cause of death in Latin America, as it causes severe chronic illness and approximately 43,000 deaths per year. To illustrate this strategy, two preliminary experiments are reported. In the first, Pavlovian conditioning was examined by pairing an olfactory conditioned stimulus with a temperature unconditioned stimulus. A temperature of 42 degrees C elicits a complex behavioral sequence in R. prolixus consisting of proboscis extension and crawling. Over the course of 12 training trials, this behavioral sequence was not elicited by an olfactory conditioned stimulus. In the second experiment, a latent inhibition paradigm was used to pre-expose R. prolixus to an olfactory conditioned stimulus before pairing the odor with temperature. Over the course of training, an effect of pre-exposure was found. Suggestions for research are discussed and potential conditioned and unconditioned stimuli identified.     

Demographic variables and microCog performance: relationships for VA patients under treatment for substance abuse

The associations of demographic variables with cognitive performance, as measured by the MicroCog ability domain scores, were assessed with 222 substance abusers who were patients in a VA medical center. Analysis indicated that age was negatively related to all five outcomes scores, and education was positively related to measures assessing Attention/Mental Control and Reasoning/Calculation. These findings are consistent with past theoretical and applied research. The demographic variables, as a group, accounted for a total of 17% to 37% of the variance in the five domain scores.     

Narrative representations of caregivers and emotion dysregulation as predictors of maltreated children's rejection by peers

This study examined whether maltreated children were more likely than nonmaltreated children to develop poor-quality representations of caregivers and whether these representations predicted children's rejection by peers. A narrative task assessing representations of mothers and fathers was administered to 76 maltreated and 45 nonmaltreated boys and girls (8-12 years old). Maltreated children's representations were more negative/constricted and less positive/coherent than those of nonmaltreated children. Maladaptive representations were associated with emotion dysregulation, aggression, and peer rejection, whereas positive/coherent representations were related to prosocial behavior and peer preference. Representations mediated maltreatment's effects on peer rejection in part by undermining emotion regulation. Findings suggest that representations of caregivers serve an important regulatory function in the peer relationships of at-risk children.     

Electronic monitoring and counseling to improve medication adherence

Electronic caps, pill caps that record the date and time of pill bottle opening provide an objective measure of adherence to prescribed medication. A promising intervention to improve adherence, cue-dose training, involves reviewing patients' pill cap-generated reports concerning their medication-taking and offering individualized recommendations for remembering to take medications at specific times of day. In this preliminary study, 79 patients prescribed the antihyperglycemic medication metformin had adherence assessed during a 4-week baseline period. Adherence, defined as proportion of prescribed doses taken within a predetermined 4-h window, was measured using electronic MEMS caps. Those who had less than 80% baseline adherence (n = 33) were randomly assigned to either receive 4 months of cue-dose training (n = 16) or to a control group (n = 17). Cue-dose training was associated with significantly better adherence to metformin (mean improvement of 15%). The effects of cue-dose training on adherence to other antihyperglycemic medication did not reach statistical significance. Glycosylated hemoglobin (a measure of blood sugar control) did not differ between groups. Data from nine patients who reviewed pill cap-generated data with their primary care providers suggested that both patients and providers found the discussion moderately helpful and not at all uncomfortable.     

Status,testosterone, and human intellectual performance: stereotype threat as status concern

Results from two experiments suggest that stereotype-threat effects are special cases of a more general process involving the need to maintain or enhance status. We hypothesized thatsituations capable of confirming a performance stereotype might representeither a threat to status or an opportunity for enhancement of status,depending on the nature of the stereotype. The positive relationship betweenbaseline testosterone and status sensitivity led us to hypothesize that hightestosterone levels in males and females would amplify existing performanceexpectations when gender-based math-performance stereotypes were activated.In Study 1, high-testosterone females performed poorly on a math test when anegative performance stereotype was primed. In Study 2, high-testosteronemales excelled on a math test when a positive performance stereotype wasprimed. The moderating effect of testosterone on performance suggests that astereotype-relevant situation is capable of conferring either a loss or again of status on targets of the stereotype.