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.     

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.     

Monkeys show an oblique effect.

Monkeys aligned a cursor bar with high-contrast square-wave gratings presented in a variety of orientations. Alignment time increased with increasing spatial frequency from 6 to 24 cycles deg-1 regardless of the orientation of the grating. At higher spatial frequencies, alignment tasks took longer for obliquely oriented gratings than for horizontal and vertical ones. Reducing grating contrast by blurring the image of the 24 cycle deg-1 grating also produced longer alignment times for the obliques. These data indicate that monkeys have an oblique effect similar to that found in humans, implying that the monkey is a useful animal model for investigating the development of meridional anisotropies.     

Low-cost equipment for schedule generation III: Variable ratio and ancillary equipment

Circuits are described that extend earlier designs for schedule-generating equipment using complementary metal oxide semiconductor (CMOS) logic. Specifically, the circuits consist of a variable-ratio generator and a series of circuits providing ancillary equipment, including a simple elapsed-timer meter, a logic probe, a variety of logic functions, a pulse generator, and circuits for interfacing. All circuits are compatible with those previously described.     

Childhood Attention-Deficit/Hyperactivity Disorder Predicts Intimate Partner Victimization in Young Women

Attention-deficit/hyperactivity disorder (ADHD) is associated with interpersonal dysfunction during childhood and adolescence, yet little is known about the romantic relationships of young women with childhood ADHD. In the present study, we draw from a longitudinal sample of girls followed prospectively into young adulthood, comparing those with (n?=?114) and without (n?=?79; comparisons) childhood ADHD in terms of their risk for physical victimization by an intimate partner (physical IPV; e.g., slapping, punching) by 17–24 years of age. We examined ADHD both diagnostically and dimensionally, at the same time establishing reliable indicators of young adult physical IPV. Externalizing and internalizing problems, and academic achievement during adolescence, were tested as potential mediators. Overall, participants with a childhood diagnosis of ADHD experienced more physical IPV than did comparisons (30.7 % vs. 6.3 %). In parallel, IPV was associated with higher levels of childhood ADHD symptomatology (d?=?0.73). Young women with persistent ADHD stood the highest risk of experiencing IPV (37.3 %), followed by those with transient ADHD (19.0 %) and those never-diagnosed (5.9 %). Academic achievement measured during adolescence was a significant partial mediator of the childhood ADHD symptomatology-young adult IPV relationship, even with control of sociodemographic, psychiatric, and cognitive factors, including childhood reading and math disorders. Findings indicate that in young women, childhood ADHD is a specific and important predictor of physically violent victimization in their intimate relationships. This vulnerable population requires IPV prevention and intervention, with academic empowerment as a key target.