Representational momentum and the flash‐lag effect

Representational momentum (RM) is a distortion where the final orientation of a moving object is misremembered as further along its trajectory. Experiments reported here examine RM when an additional object was flashed just as the moving object disappeared. When the task was to judge the flashed object, participants reported that the flash appeared to lag behind (flash‐lag effect; FLE). When the task was to judge the moving object, larger forward distortions for the moving object were found when the flash was present, despite previous evidence that the FLE depends on the moving object's continued presence. The results suggest that some part of the FLE depends upon what precedes the flash. In addition, equivalent RM was observed for implied and smoothly animated events, a possible limit to the velocity effect for RM was found, and larger positive distortions were found for downward rotations.     

Response to commentary on the multimodal treatment study of ADHD (MTA): mining the meaning of the MTA

In the December 2000 issue of the Journal of Abnormal Child Psychology, we published a set of papers presenting secondary analyses of the Multimodal Treatment Study of ADHD (MTA), and R. A. Barkley (2000) provided a commentary. A critique of the design of the study (MTA Cooperative Group, 1999) was presented based on a theoretical perspective of a behavioral inhibition deficit that has been hypothesized as the core deficit of ADHD (R. A. Barkley, 1997). The commentary questioned the design and analysis of the MTA in terms of (1) the empirical criteria for selection of components of behavioral (Beh) intervention, (2) the effectiveness of the Beh intervention, (3) the methods for analyses at the group and individual level, (4) implications of the MTA findings for clinical practice, (5) the role of genetics in response to treatment, and (6) the lack of a nontreatment control group. In this response, we relate the content of the papers to the commentary, (1) by reviewing the selection criteria for the Beh treatment, as outlined by K. C. Wells, W. E. Pelham, et al. (2000), (2) by addressing the myth that the MTA Beh treatment was ineffective (Pelham, 1999), (3) by describing the use of analyses at the level of the individual participant, as presented by J. S. March et al. (2000) and W. E. Pelham et al. (2000) as well as elsewhere by J. M. Swanson et al. (2001) and C. K. Conners et al. (2001), (4) by relating some of the suggestions from the secondary analyses about clinically relevant factors such as comorbidity (as presented by J. S. March et al., 2000) and family and parental characteristics (as presented by B. Hoza et al., 2000, S. P. Hinshaw et al., 2000, and K. C. Wells, J. N. Epstein, et al., 2000), (5) by discussing the statistical concept of heritability and the lack of a significant difference in the presence of ADHD symptoms in parents of the MTA families compared to parents in the classmate-control families (as presented by J. N. Epstein, et al., 2000), and (6) by acknowledging that an ethically necessary weakness of the MTA design is that it did not include a no-treatment control group. We discuss the use of secondary analyses to suggest how, when, and for what subgroups effectiveness of the Beh treatment may have been manifested. Finally, we invite others to use the large and rich data set that will soon be available in the public domain, to perform secondary analyses to mine the meaning of the MTA and to evaluate theories of ADHD and response to treatments.     

A Longitudinal Study of Interparental Conflict, Emotional and Behavioral Reactivity, and Preschoolers' Adjustment Problems among Low-Income Families

Researchers have begun to develop models that explain the processes by which interparental conflict impacts children's adjustment. The present study tested a model based on emotional security theory. The longitudinal relations among interparental conflict, boys' reactions to conflict, and internalizing and externalizing problems were examined in a sample of 129 mother–son dyads from low-income, 2-parent families from the time sons were age 2 to 5. Results indicated that children exposed to interparental conflict were more likely to have concurrent and later behavior problems and that patterns of interparental conflict across time made unique contributions in predicting later problems. Children's emotional reactivity in response to conflict had no direct relation to interparental conflict and only modest relations to behavior problems. However, interparental conflict and reactivity factors interacted to predict behavior problems at ages 3 1/2 and 5. Thus, some support was demonstrated for emotional reactivity as a moderator in the development of young children's behavior problems.     

Word-to-word variation in ERP component latencies: spoken words

Data were collected shedding light on the brain electrical activity underlying word recognition. Subjects listened to a list of 48 spoken words in six random orders under two instructional sets: first to "think about the meanings of the words," and second, to learn the list. The scalp EEG associated with hearing and identifying the words was recorded at F3, F4, Cz, P3, P4, Pz, and Oz. Standard within-subjects time-locked averaging across words showed a late negative-positive complex with N2-P3 topography, the negative component peaking around 480 msec, the positive component peaking around 830 msec. Averaging within words across subjects uncovered considerable latency variability in both components. Within-word N2 and P3 component latencies covaried with word durations and with the "recognition points" predicted for the words by the "cohort theory" of word recognition. N2 latencies corresponded closely to the "N400" effect elicited with semantically incongruous sentence-final spoken words. Implications for ERP investigations of language processing are discussed.     

Low-cost equipment for schedule generation: II. Time-dependent schedules

Complementary metal oxide semiconductor (CMOS) logic provides an efficient and convenient technology for the generation of schedules of reinforcement. A single circuit provides a module capable of use as either a fixed-interval timer or one generating a differential reinforcement of low-rate schedule. A second circuit provides for a programmable variable-interval generator with 16 independent intervals. Both modules are fully compatible with previously described circuits for ratio schedules.     

Autoshaped responding: A baseline for studying stimulus preference

In an autoshaping procedure with pigeons, trials consisted of the illumination of two keys, each with a different color, and then a response-independent feeder operation. Over successive conditions, all key-color pairs were arranged from the set of amber, red, green, and blue lamps. During sessions with a given pair, the left-right configuration of the colors varied irregularly, and the two colors alternated in illuminating the feeder. With one red and one green key, for example, red appeared sometimes on the left and sometimes on the right, and the feeder was alternately lit red or green on successive trials. Both total pecks and proportion of trials with at least one peck on a key of a given color were generally greater for red and amber than for green and blue, and relations among preferences were generally transitive across different color pairs. Repeating the procedure with decreased red and amber intensities and increased green and blue intensities reduced red and amber pecking relative to green and blue pecking, implying that differences in responding were determined more strongly by intensive than by chromatic properties of the stimuli.     

The temporal course of the relationship between retinal disparity and the equidistance tendency in the determination of perceived depth

Changes in perceived depth as a function of exposure duration were compared for two stimulus conditions. In one. a depth interval between two points of light was produced by the retinal disparity cue, and in the other condition, otherwise identical to the first, the light points were connected by a thin luminous line. The principle finding was that the perceived depth interval between the light points increased as a function of exposure durations greater than 1 sec, while no change in the perceived depth interval between the end points of the line occurred. The results were interpreted in terms of a greater equidistance tendency (ET) operating for the line than for the point condition. It was concluded that both the ET and the retinal disparity cue increase in strength as a function of exposure duration.     

The Development of Early Externalizing Problems Among Children from Low-Income Families: A Transformational Perspective

The present study examined pathways leading to early externalizing problems from age 1 to 31/2 in a design that took advantage of our knowledge of normative progression and normative socialization as well as findings from research on risk. A sample of 130 low-income participants was followed longitudinally from 12 to 42 months using observational measures of developmentally salient parenting and child disruptive behavior to predict early externalizing problems. Results are best accommodated by concepts such as transformation and transaction from developmental psychology. For boys, both child and parent variables predicted later externalizing. For girls and boys, the interaction between child noncompliance and maternal rejection was significant.     

Relations between infant irritability and maternal responsiveness in low-income families

Relations between infant irritability and maternal responsiveness at 12 and18 months were investigated in low-income mother-infant dyads. Emphasis was placed on whether results varied according to measurement strategies, infant gender, or level of maternal social support and satisfaction with that support. Irritability was measured separately through observation and maternal report, responsiveness was measured observationally, and maternal social support and satisfaction were self-reported via questionnaire. Concurrent relations between irritability and responsiveness were, in general, negative and were larger when irritability was measured observationally rather than by maternal report. Correlations were similar across gender. No longitudinal relations were found between irritability and responsiveness. Amount of maternal social support was weakly related to responsiveness and to responses to infant irritability, and the nature of these relations was unexpected. Irritability-responsiveness relations varied as a function of measurement strategies, which may in part explain mixed findings in the empirical literature.