Constructing a scientific paper: Howell's prothrombin laboratory notebook and paper

Scientists generally record their laboratory activities and experimental results in notebooks, from which they construct scientific papers. The Johns Hopkins physiologist William Henry Howell kept a laboratory notebook from 1913 to 1914, in which he recorded experiments on the blood clotting factor prothrombin. In 1914 he published a paper using this notebook, to justify his theory of prothrombin activation. Howell's paper is reconstructed, in terms of its narrative and argument elements, from the laboratory activities and experimental results recorded in the notebook. This reconstruction reveals an intimate connection between the two texts and the process by which Howell constructed a scientific paper. The generation of scientific knowledge by Howell is then evaluated, especially in terms of theory formation and justification.     

Cognitive sex differences: speed and problem-solving strategies on computerized neuropsychological tasks

Skill, strategy, and laterality measures obtained through computerized neuropsychological tasks, a reaction time (RT) test, and a visuospatial problem-solving test, the Perceptual Maze Test, were analyzed in relation to sex and handedness of 56 high-school students. Boys were significantly faster than girls on most RT subtasks (including a response-inhibition task) and made more two-choice RT response errors for right-sided stimuli, which may be interpreted as resulting from a less cautious strategy. In maze performance, boys were superior to girls. An analysis of separate phases of the maze-solution process suggested that boys preferentially used an impulsive-global strategy. Girls, using a more reflective-sequential task-solving strategy, were significantly slower, without hitting more targets. Compared to all other groups, left-handed girls (strongly left-handed) had lower performance on maze tasks with no target information, particularly in left-sided solution pathways. Results were interpreted as reflecting differences in hemispheric competence and activation patterns between the sexes. Signs of a less differentiated lateralization and slight dysfunction of visuospatial skills in the left-handed girls were discussed.     

Revisiting the metacontrast dissociation: comparing sensitivity across different measures and tasks

In the metacontrast dissociation procedure, presenting a masked shape prime prior to a visible shape target leads to reaction-time effects of the prime in an indirect measure, although participants cannot consciously detect prime shapes in a direct measure (Klotz & Neumann, 1999). This has been taken as evidence for the processing of unconscious input. The results of the present metacontrast dissociation study indicate that although participants are unable to consciously report the shape of the prime, they can consciously perceive motion between masked primes and visible targets in a hybrid direct/indirect measure (Experiments 1 and 3). This indicates that former tests did not provide an exhaustive measure for residual conscious perception of the prime in the metacontrast dissociation procedure. Further tests, however, reveal that residual motion perception cannot account for performance in the indirect measure (Experiments 2 and 3). Although the results thus leave the conception of processing of unconscious input intact, they may prompt a revision of its criteria.     

Test-retest reliability of standard and emotional stroop tasks: an investigation of color-word and picture-word versions

Previous studies have examined the reliability of scores derived from various Stroop tasks. However, few studies have compared reliability of more recently developed Stroop variants such as emotional Stroop tasks to standard versions of the Stroop. The current study developed four different single-stimulus Stroop tasks and compared test-retest reliabilities. The four Stroop tasks included two standard Stroop tasks (color-word and picture-word) as well as two emotional Stroop tasks (color-word and picture-word). The four Stroop tasks were administered on two occasions, separated by 1 week, to 28 undergraduate students. Test-retest reliability coefficients were high for standard and emotional Stroop tasks when reliability was measured using response latencies alone. However, test-retest coefficients were unacceptably low when reliability estimates were calculated using difference scores. The findings have important implications for clinical and experimental use of standard and emotional Stroop tasks.     

Design and organization in a computerized psychology laboratory

This paper presents six; principles of laboratory organization and design. These six principles are an outgrowth of the past 7 years’ experience in the Mathematical Models Laboratory of the Psychology Department at Indiana University. Each of the six principles is formally stated and then followed by explanation and examples.     

Pigeons (Columba livia) plan future moves on computerized maze tasks

Planning, the internal process of formulating an organized method about one's future behavior, should be advantageous for non-human animals as well as for humans. However, little is known about this process in avian species. We examined planning processes in pigeons (Columba livia) using a computerized maze task. In Experiment 1, we found that the pigeons plan their next one step, and in some cases even correctly adjust their actions after change of goal locations, while performing on a plus-shaped maze. We also showed that the pigeons might even plan two steps on familiar, well-practiced mazes. In Experiment 2, we discovered that the subjects plan the direction they would go first before starting to solve a four-arm shuriken (a Japanese traditional throwing knife)-shaped maze. The birds also corrected their previously planned actions after change of goal locations. Our results from these experiments suggest that planning ahead is within the cognitive capacity of a "bird brain", and that it may be more widespread in the animal kingdom than has been presumed.     

Expansions on a computerized operant laboratory: Considerations for combining teaching and research

The present laboratory configuration addresses concerns beyond the functional workings of a computerized research system to include human factors. The logistical aspects of error-free multi-operator operations are discussed along with the economics of developing, assembling, and maintaining the stations. The actual configurations (hardware and software) of the present laboratory are explained and discussed, as are the philosophies and experiences that led to a highly successful combined research and teaching operant laboratory.     

A retrospective analysis of alcohol consumption on laboratory tasks as related to therapeutic outcome

The relationship between drinking on laboratory-analogue measures at the onset of inpatient alcoholism treatment and abstinence subsequent to treatment was examined. Twenty therapeutically successful and 20 unsuccessful chronic alcoholics were selected and did not differ on age, education, length of problem drinking, and length of follow-up. Retrospective analysis of responding on an operant drinking task and a ‘taste test’ assessment technique revealed significant differences between the groups, with successful patients drinking less than the unsuccessful ones. Implications for screening candidates for alcoholism treatment programs are discussed.     

PET activation studies comparing two speech tasks widely used in surgical mapping

"Automatic" speech, especially counting, is frequently preserved in aphasia, even when word production is severely impaired. Although brain sites and processes for automatic speech are not well understood, counting is frequently used to elicit fluent speech during preoperative and intraoperative cortical mapping for language. Obtaining both behavioral and functional brain imaging measures, this study compared counting with a word production task (generation of animal names), including non-verbal vocalizations and quiet rest as control states, in normal and aphasic subjects. Behavioral data indicated that normal and aphasic groups did not differ in counting or non-verbal vocalizations, but did differ significantly in word production ("naming" animals). Functional brain imaging results on normal subjects using partial least squares analysis of PET rCBF images revealed three significant latent variables (LVs): one for naming and vocalizing, identifying bilateral anterior areas, with left predominating over right; a second LV for naming, identifying left and right frontal and temporal areas. For the third, only marginally significant LV, which was associated with automatic speech alone (counting), right and subcortical sites predominated. For patients, two LVs emerged, identified with naming and vocalization, and corresponding to a variety of cerebral sites; the analysis failed to find a specific latent variable for counting. A comparison between group data for normal subjects and patients suggested that the naming, counting, and vocalization tasks were performed differently by the two groups. These results suggest that word generation as a verbal task is more likely to elicit activity in classical language areas than counting. Further studies are suggested to better understand differences between neurological substrates for non-propositional and automatic speech.     

Immediate and delayed memory tasks: A computerized behavioral measure of memory, attention, and impulsivity

The Immediate and Delayed Memory Task (IMT/DMT), a variant of the Continuous Performance Test (CPT), is a new software package designed to be a flexible research tool for the study of attention, memory, and impulsivity. This package allows researchers to determine the design to be used during a testing session and to manipulate many of the parameters. It features two components: the IMT and the DMT, both of which present sequential 2- to 7-digit stimuli with variable presentation rates and intertrial intervals. Subjects respond to identically matched stimuli presented consecutively, spanning a brief period of time (IMT), or to stimuli spanning a greater period of time (during which intervening stimuli to be ignored appear; DMT). Task complexity can be adjusted to suit applications for both children and adults. Preliminary studies have demonstrated that these laboratory tasks are sensitive to group differences, produce stable baselines of performance, and are sensitive to drug-induced performance decrements.     

Bootstrap methods for comparing independent regression slopes

In this study, we explore the effects of non-normality and heteroscedasticity when testing the hypothesis that the regression lines associated with multiple independent groups have the same slopes. The conventional approach involving the F-test and the t-test (F/t approach) is examined. In addition, we introduce two robust methods which allow simultaneous testing of regression slopes. Our results suggest that the F/t approach is extremely sensitive to violations of assumptions and tends to yield misleading conclusions. The new robust alternatives are recommended for general use.     

Selective effects of motor expertise in mental body rotation tasks: comparing object-based and perspective transformations

Brain imaging studies provide strong evidence for the involvement of the human mirror system during the observation of complex movements, depending on the individual's motor expertise. Here, we ask the question whether motor expertise not only affects perception while observing movements, but also benefits perception while solving mental rotation tasks. Specifically, motor expertise should only influence the performance in mental body rotation tasks (MBRT) with left-right judgment, evoking a perspective transformation, whereas motor expertise should not affect the MBRT with same-different judgment, evoking an object-related transformation. Participants with and without motor expertise for rotational movements were tested in these two conditions in the MBRT. Results showed that motor experience selectively affected performance in the MBRT with the left-right judgment, but not with same-different judgment. More precisely, motor expertise only benefited performance when human figures were presented in (for non-experts) unfamiliar, upside-down body orientations.     

Timed performance weaknesses on computerized tasks in pediatric brain tumor survivors: A comparison with sibling controls

With more children surviving a brain tumor, insight into the late effects of the disease and treatment is of high importance. This study focused on profiling the neurocognitive functions that might be affected after treatment for a pediatric brain tumor, using a broad battery of computerized tests. Predictors that may influence neurocognitive functioning were also investigated. A total of 82 pediatric brain tumor survivors (PBTSs) aged 8–18 years (M = 13.85, SD = 3.15, 49% males) with parent-reported neurocognitive complaints were compared to a control group of 43 siblings (age M = 14.27, SD = 2.44, 40% males) using linear mixed models. Neurocognitive performance was assessed using measures of attention, processing speed, memory, executive functioning, visuomotor integration (VMI), and intelligence. Tumor type, treatment, tumor location, hydrocephalus, gender, age at diagnosis, and time since diagnosis were entered into regression analyzes as predictors for neurocognitive functioning. The PBTSs showed slower processing speeds and lower intelligence (range effect sizes .71–.82, p < .001), as well as deficits in executive attention, short-term memory, executive functioning, and VMI (range effect sizes .40–.57, p < .05). Older age at assessment was associated with better neurocognitive functioning (B = .450, p < .001) and younger age at diagnosis was associated with lower intelligence (B = .328, p < .05). Medical risk factors, e.g., hydrocephalus, did not show an association with neurocognitive functioning. Late effects in PBTSs include a broad range of neurocognitive deficits. The results suggest that even PBTSs that were traditionally viewed as low risk for neurocognitive problems (e.g., surgery only, no hydrocephalus) may suffer from decreased neurocognitive functioning.     

Effects of teaching an introductory psychology laboratory using a computerized research tool

In the introductory psychology laboratory at Drexel University, we employ courseware modules that transform the computer into various pieces of psychological research equipment. Students enrolled in this course use the courseware modules in a series of experiments that investigate motor learning, perception, memory, and other psychological phenomena. In choosing this form of computerization, we have encountered challenges to our methods of instruction, both in the laboratory and in the lecture hall. Opportunities, in the form of financial and programming assistance, have also resulted from our computerization efforts.     

Recruitment of anterior and posterior structures in lexical-semantic processing: an fMRI study comparing implicit and explicit tasks

Previous studies examining explicit semantic processing have consistently shown activation of the left inferior frontal gyrus (IFG). In contrast, implicit semantic processing tasks have shown activation in posterior areas including the superior temporal gyrus (STG) and the middle temporal gyrus (MTG) with less consistent activation in the IFG. These results raise the question whether the functional role of the IFG is related to those processes needed to make a semantic decision or to processes involved in the extraction and analysis of meaning. This study examined neural activation patterns during a semantic judgment task requiring overt semantic analysis, and then compared these activation patterns to previously obtained results using the same semantically related and unrelated word pairs in a lexical decision task which required only implicit semantic processing (Rissman, J., Eliassen, J. C., & Blumstein, S. E. (2003). An event-related fMRI investigation of implicit semantic priming. Journal of Cognitive Neuroscience, 15, 1160-1175). The behavioral results demonstrated that the tasks were equivalent in difficulty. fMRI results indicated that the IFG and STG bilaterally showed greater activation for semantically unrelated than related word pairs across the two tasks. Comparison of the two task types across conditions revealed greater activation for the semantic judgment task only in the STG bilaterally and not in the IFG. These results suggest that the pre-frontal cortex is recruited similarly in the service of both the lexical decision and semantic judgment tasks. The increased activation in the STG in the semantic judgment task reflects the greater depth of semantic processing required in this task and indicates that the STG is not simply a passive store of lexical-semantic information but is involved in the active retrieval of this information.     

ADHD outside the laboratory: boys' executive function performance on tasks in videogame play and on a visit to the zoo

One current theory of attention-deficit/hyperactivity disorder (ADHD) proposes that a primary deficit in behavioral inhibition gives rise to secondary deficits in 4 executive functions and motor control. To date, empirical support for this model is based primarily on laboratory-based cognitive methods. This study assessed behavioral inhibition and executive functioning in children with ADHD in 2 real-life contexts: videogames (motor-skill target game, cognitively demanding adventure game) and an outing at the zoo (route tasks). Participants were a community sample of 57 boys diagnosed with ADHD (20 inattentive, 37 combined type) and 57 normally developing control boys, matched individually for age and nonverbal IQ. Operationally defined measures of behavioral inhibition and specific executive functions were derived from these activities and assessed under contrasting conditions of low or high working memory and distractor loads. There were no group differences in basic motor skills on the target game, nor in terms of the ability to inhibit a prepotent or ongoing response in the adventure videogame. However, boys with ADHD exhibited more self-talk, more effortful response preparation, and completed fewer challenges in the latter videogame. Also, they manifested inhibition deficits in terms of interference control during the route task at the zoo and took longer to complete the tasks. Typically, these differences were greatest under conditions of high working memory and distractor loads. Findings from this study suggest that cognitive difficulties in ADHD may be context dependent and that ADHD is associated with deficits in some but not all aspects of behavioral inhibition.     

Developing new online calibration methods for multidimensional computerized adaptive testing

Multidimensional computerized adaptive testing (MCAT) has received increasing attention over the past few years in educational measurement. Like all other formats of CAT, item replenishment is an essential part of MCAT for its item bank maintenance and management, which governs retiring overexposed or obsolete items over time and replacing them with new ones. Moreover, calibration precision of the new items will directly affect the estimation accuracy of examinees’ ability vectors. In unidimensional CAT (UCAT) and cognitive diagnostic CAT, online calibration techniques have been developed to effectively calibrate new items. However, there has been very little discussion of online calibration in MCAT in the literature. Thus, this paper proposes new online calibration methods for MCAT based upon some popular methods used in UCAT. Three representative methods, Method A, the ‘one EM cycle’ method and the ‘multiple EM cycles’ method, are generalized to MCAT. Three simulation studies were conducted to compare the three new methods by manipulating three factors (test length, item bank design, and level of correlation between coordinate dimensions). The results showed that all the new methods were able to recover the item parameters accurately, and the adaptive online calibration designs showed some improvements compared to the random design under most conditions.