Hyperactivity and Learning Deficits in Transgenic Mice Bearing a Human Mutant Thyroid Hormone β1 Receptor Gene

Resistance to thyroid hormone (RTH) is a human syndrome mapped to the thyroid receptor β (TRβ) gene on chromosome 3, representing a mutation of the ligandbinding domain of the TRβ gene. The syndrome is characterized by reduced tissue responsiveness to thyroid hormone and elevated serum levels of thyroid hormones. A common behavioral phenotype associated with RTH is attention deficit hyperactivity disorder (ADHD). To test the hypothesis that RTH produces attention deficits and/or hyperactivity, transgenic mice expressing a mutant TRβ gene were generated. The present experiment tested RTH transgenic mice from the PV kindred on behavioral tasks relevant to the primary features of ADHD: hyperactivity, sustained attention (vigilance), learning, and impulsivity. Male transgenic mice showed elevated locomotor activity in an open field compared to male wild-type littermate controls. Both male and female transgenic mice exhibited impaired learning of an autoshaping task, compared to wild-type controls. On a vigilance task in an operant chamber, there were no differences between transgenics and controls on the proportion of hits, response latency, or duration of stimulus tolerated. On an operant go/no-go task measuring sustained attention and impulsivity, there were no differences between controls and transgenics. These results indicate that transgenic mice bearing a mutant human TRβ gene demonstrate several behavioral characteristics of ADHD and may serve a valuable heuristic role in elucidating possible candidate genes in converging pathways for other causes of ADHD.     

GENERALITY AND SIDE EFFECTS OF OVERCORRECTION1

The effects and side effects of overcorrection for self-stimulatory behaviors of two children in a specialized day-care program were evaluated. For one child, a “hand” overcorrection procedure involving arm and hand exercises was introduced contingent upon inappropriate hand movements and later contingent upon inappropriate foot movements. After “hand” overcorrection was withdrawn for inappropriate foot movements, a “foot” overcorrection procedure involving foot and leg exercises was introduced contingent upon inappropriate foot movements. For a second child, the “hand” overcorrection procedure was introduced contingent upon inappropriate hand movements during a free-play period, and later contingent upon inappropriate vocalizations at naptime. “Hand” overcorrection was withdrawn and then re-introduced sequentially for both behaviors. Several concurrent behaviors were measured to assess multiple effects of treatment. Results for both children indicated the “hand” overcorrection procedure suppressed inappropriate hand movements and inappropriate behaviors that were topographically dissimilar. In addition, inverse relationships were observed between the second child's inappropriate hand movements and appropriate toy usage during free play and between his inappropriate vocalizations and inappropriate foot movements during naptime. Results suggest that overcorrection procedures that are effective for one behavior can be used to reduce the frequency of topographically different behaviors. This finding is discussed in terms of its practical implications for therapists.     

Thalamic modulation of aggression

Integrative Psychological and Behavioral Science - This experiment extends Pavlov’s method of contrasts for 8 components of aggression were quantitatively evaluated in 11 freely moving adult...     

Baby X

The present study investigated adult behavior while interacting with a three-month-old infant under conditions in which the child was introduced as a boy, as a girl, or with no gender information given. Gender labels did not elicit simple effects, but rather interacted significantly with the sex of the subject on both toy usage and physical contact measures. There was a stronger tendency for both male and female adults to utilize sex-stereotyped toys when the child was introduced as a girl. Most of the findings, however, reflected a differential response of men and women to the absence of gender information. In this condition, male subjects employed a neutral toy most frequently and handled the child least; in contrast, females used more stereotyped toys and handled the child more. All subjects attempted to guess the gender of the child (with “boy” guesses more frequent, although the child was actually female) and all justified their guess on the basis of stereotyped behavioral or physical cues like strength or softness.     

Post-retinal storage? Some further observations on Parks’ camel as seen through the eye of a needle

Parks recently reported observations with an apparatus in which successive slices of a stimulus figure could be entered on the same retinal locus. He reported that when this was done, a visual percept of the figure appeared, but one that appeared condensed in length. From this he argued that the slices, differing only in time of arrival, must be stored post-retinally and then reconstructed spatially to form the coherent figure again. In attempting to replicate this important conclusion, we found, contrary to Parks, that the appearance of the percept occurred only when the slices were spread out over the retina, and not when they were entered on the same spot. Thus, the percept is probably due to much more understandable poor temporal resolution, rather than spatial integration. Shape distortions were found corresponding to Parks’ reports, but only in the absence of any visual percepts. In spite of the failure to support all of Parks’ conclusions, the effects are seen as very intriguing ones, and may have critical theoretical ramifications.     

Effective list length and part-whole transfer in first-graders' multitrial free recall

First-gradens' multitrial free recall shows an effective list-length (ELL) effect: an initial recall gain followed by a constant output level that fluctuates in item content. The part-whole transfer paradigm was used to investigate ELL. The ELL effect occurred in whole-list learning regardless of whether the prior task consisted of relevant practice, irrelevant practice, or an unrelated task. Relevant part-list learning resulted in positive transfer which declined from a high to a marginal level over the course of whole-list learning. Other analyses indicated a general deficit in the use of strategies. A response-strength model was used to explain the ELL effect and the transfer results.     

Correction for Range Restriction in Meta‐Analysis Revisited: Improvements and Implications for Organizational Research

In this study, we present a more accurate method for correcting for range restriction (Case V) that expands upon Bryant and Gokhale's (1972) method. We further present detailed steps to incorporate the Case V method into Schmidt and Hunter's (2015) psychometric meta‐analysis methods (both individual correction and artifact distribution approaches). We then evaluate the accuracy of the Case V method vis‐à‐vis existing methods. Monte‐Carlo simulation results indicate that the Case V method provides very accurate estimates for the mean true score correlation and reasonably accurate estimates for the true standard deviation. More important, Case V almost always provides more accurate results than alternative methods (particularly, Case IV). To illustrate how the Case V method works with real data, we conduct a reanalysis of Judge, Heller, and Mount's (2002) meta‐analysis examining the relationships between the Big 5 personality traits and job satisfaction. Results indicate that the true score correlations between the Big 5 traits and job satisfaction have been underestimated, whereas their true standard deviations have been overestimated. Implications for range restriction corrections in organizational research are discussed.