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At least 1,333 records · Page 74Linked to original sources
PubMed1979

Effects of left-right orientation and position reversals on spatial perspective taking in young children.

50 boys and 50 girls, from Grades K through 4, were presented with 180 degrees perspective-taking tasks that varied arrays in terms of the number of front-back and left-right orientation reversals and left-right position reversals. Results confirmed existing evidence that left-right orientation reversals are more difficult than front-back orientation reversals in arrays of one object. However, with arrays of two objects, left-right orientation reversals appear easier than front-back orientation reversals, apparently because of the relationship between the objects.

Child↗
PubMed1994

Visual evoked potentials of adaptation to left-right reversed vision.

During the course of the adaptation to left-right reversed vision, visually, evoked potentials (VEPs) were measured for a light flash presented on either side of a fixation. The VEP amplitudes and latencies changed drastically as the adaptation progressed. The time course of the change was quite different between occipital scalp loci. These results indicate that the adaptation to the optical distortion takes place even in the relatively early stage of the visual information processing.

Adult↗
PubMed1995

Stimulus-response compatibility and videogame performance.

We investigated the role of stimulus-response compatibility in influencing manual reactions to a moving visual target in a videogame (pong). 40 right-handed university men were assigned randomly to one of two experimental conditions, the normal game condition or a reverse control condition in which the response device on the right controls the left game paddle and the device on the left controls the right paddle. Subjects in the normal condition performed marginally better playing pong when seated on the right when seated on the left, consistent with earlier findings. However, subjects in the reverse control condition showed the reverse effect, a left-side advantage. These findings suggest that compatibility between location of the moving target (the ball) and either handedness or hand used to respond may have been responsible for the right-side advantage observed in the normal-game condition.

Adult↗
PubMed1996

Auditory and visual recall of forward and backward digit spans.

Increasingly, clinicians obtain data from tests across modalities. Little actual information, however, exists as to normal patterns. An example is auditory and visual recall of digit span. The effects of modality on recall of digit span, sequence, and order were examined with 80 subjects (M age 24.3 yr.). Subjects were given the Wechsler Adult Intelligence Scale-Revised, and a research version of MicroCog: Assessment of Cognitive Functioning. Both contain forward and backward digit spans. Recall for visual presentation was significantly stronger than for auditory presentation of backward digit span. Recall for visual backward digit span was also superior to auditory backward digit span when the sequence of presentation was controlled. The mean number of digits recalled was higher when visual digit span was preceded by auditory digit span.

Adult↗
PubMed1999

Relearning movements: modification of an incorrectly timed reversal movement.

The main purpose of this study was to examine if an inaccurately acquired motor response can be relearned through the provision of a limited number of correct KR trials. 26 subjects were assigned to one of three experimental groups: a no-KR group, an erroneous KR group, and a relearning group who were given correct KR after 125 trials of erroneous KR. Analysis showed a significant temporal correction of the reversal movement when the erroneous KR was replaced by valid verbal information during acquisition. This adaptation, however, was attenuated during retention, indicating that the limited number of correct KR trials did not wash out the effect of the invalid information provided during the first phase of acquisition.

Adolescent↗
PubMed2001

Spatial property of motion visual evoked potentials.

The cortical evoked response to drifting patterns (motion visual evoked potentials) was investigated. When the direction of motion of the stimulus pattern was reversed upward or downward at intervals, the cortical evoked response was triggered at the moment when the pattern changed direction. The polarity reversal of the main negative component occurred between upper and lower visual field stimulations as seen in pattern reversal visual evoked potentials. Our study indicates these potentials have a compound property reflecting the visual field.

Adult↗
PubMed2006

Simultaneous specification of amplitudes and directions of bimanual reversal movements.

Intermanual interactions are modulated by task requirements in the course of motor preparation. In particular, amplitude coupling is strong when identical amplitudes are specified concurrently for the 2 hands but relaxed when different amplitudes are specified. Similarly, directional coupling is symmetric when symmetric directions are specified concurrently but turns to parallel when parallel directions are specified. Here, the author investigated whether the modulations of amplitude coupling and directional coupling in the course of motor preparation are independent or interact. Application of the timed-response procedure, which enables one to manipulate the time available for motor preparation, in 9 participants revealed a weakly interactive pattern. Directional coupling tended to be reduced when different rather than same amplitudes were specified concurrently, and amplitude coupling tended to be reduced when parallel rather than symmetric directions were specified concurrently. In general, interactive effects were also apparent in the rates at which directions and amplitudes were specified. Those observations are consistent with the notion that intermanual amplitude and direction interference are mediated by different but partially overlapping neural structures.

Adult↗
PubMed2005

Pauses and durations exhibit a serial position effect.

This article reports evidence of two kinds of serial position effects in immediate serial recall: One involves interresponse pauses, and the other response durations. In forward and backward recall, responding was faster at initial and final positions than at center positions, exhibitinga bow-shaped function relative to serial position. These data were obtained in a spoken recall study in which ungrouped lists of four to six words and postcuing of recall direction were used. The pause pattern is consistent with several models of serial memory, including a distinctiveness model (Brown, Neath, & Chater, 2002) and a version of the ACT-R model augmented with a spontaneous grouping strategy (Maybery, Parmentier, & Jones, 2002). The duration pattern suggests that response articulation depends on the processing context, rather than being modular.

Attention↗
PubMed2003

Comparison between the lambda response of eye-fixation-related potentials and the P100 component of pattern-reversal visual evoked potentials.

The purpose of this study was to compare the lambda response of eye-fixation-related potentials (EFRPs) with the P100 component of pattern-reversal visual-evoked potentials. EFRPs were obtained by averaging EEGs time-locked to the offset of the saccade. The dipole of the lambda response and that of the P100 component were estimated by the dipole-tracing method (Musha & Homma, 1990). The locations of their dipoles at the occipital sites were very close to each other when the difference waveform, which was calculated by subtracting the EFRP to the patternless stimulus from the EFRP to the patterned stimulus, was used for the lambda response. This finding implies that the lambda response and P100 have a common neural generator in the visual cortex. However, the peak latency of the lambda response was shorter than that of P100. The saccades in the EFRP trial were considered to be the cause of the difference.

Adult↗
PubMed2000

[Parametric coupling in sequences of bimanual reversal movements with identical and different amplitudes].

In sequences of bimanual movements, the voluntary modulation of the amplitude of the one hand (inducing hand) induces an involuntary modulation of the amplitude of the other hand (dependent hand), the strength of which increases with increasing tempo. By means of a task in which subjects perform sequences of two short and two long reversal movements in alternation with the inducing hand, but constant short or long reversal movements with the dependent hand, we addressed two questions. The first question was concerned with differences in the effects of tempo on the involuntary amplitude modulation of short and long movements; the second question was whether the involuntary amplitude change fades away or is propagated when bimanual movements with certain target amplitudes are repeated. At low tempo the contralateral effect of voluntary amplitude changes on short-amplitude movements was stronger than the effect on long-amplitude movements, but at high tempo this difference was reversed. This result is not consistent with the assumption that contralateral amplitude modulation results from an overflow of efferent commands, which increases with the force of the movement; however, it is consistent with other findings on a transient coupling during amplitude specification (parametric coupling). The involuntary amplitude change was essentially propagated to the next movement in the sequence and did not fade away. This finding suggests that the assimilation of amplitudes that can be observed in bimanual sequences of movements with different, but for each hand constant, amplitudes could result from an effect of transient parametric coupling during the initial specification of amplitudes and need not necessarily be attributed to cross-talk at the level of motor commands or efferent innervation.

Adult↗
PubMedDate not supplied

Neonatal low-level lead exposure in monkeys (Macaca fascicularis): effect on two-choice non-spatial form discrimination.

Monkeys were dosed orally with 500 microgram/kg/day of lead as lead acetate from day 1 of life. No overt signs of lead toxicity were observed. At 2--3 years of age they were tested on a two-choice non-spatial form discrimination using a WGTA apparatus. Treated monkeys showed deficits compared to controls on a series of 20 discrimination reversals; there was no difference between the groups in the effect of a series of "overtraining" trials introduced between reversals.

Animals↗
PubMed1996

Alpha-phenyl-tert-butyl-nitrone (PBN) reverses age-related maze learning performance and motor activity deficits in C57 BL/6 mice.

Two experiments were performed to study the effects of age and repeated administration of alpha-phenyl-tert-butyl-nitrone (PBN), the free radical spin-trapping agent, upon spontaneous motor activity levels and radial arm maze performance in normal young (3 month old) and normal aged (15 month old) C57 BI/6 mice. In Experiment 1, the aged mice were found to show reduced locomotor and rearing behaviour in comparison with the young mice. In the radial eight-arm maze learning task, the aged mice performed at a comparable level to the young mice during the first learning trial (Day 1) but made significantly more errors and showed longer total latencies during the second trial presented 24h later. In Experiment 2, the aged and young mice were subchronically administered either PBN at a dose of 50mg/kg, s.c. over 12 days, or saline. Spontaneous motor activity was tested 72h after the last injection. 36h later the first test trial in the radial arm maze was presented; this was followed after a further 24h by the second test trial. Subchronic treatment with PBN increased locomotion counts in the aged (15 month old) mice during the 60min test period, but decreased rearing during the first 30min of the test period. In the radial arm maze, the performance deficit shown during the second test trial by the aged mice was abolished by repeated PBN administration; both the number of errors and the latencies to all eight pellets were significantly reduced in the aged mice that received PBN. PBN did not exert any effects upon the performance of the young mice. These results, considered in conjunction with other studies using gerbils or rats, implicate the involvement of free radical species in the deterioration of function in the aged C57 BI/6 mouse.

Journal Article↗
PubMed1979

[Age dependence of the P2 amplitudes of visually evoked cortical responses to checkerboard pattern reversal (author's transl)].

The age dependence of the P2 amplitudes of visually evoked cortical responses to checkerboard pattern reversal was examined in 72 healthy individuals of between 10 and 69 years of age. Separate examination of the right and left eye yielded no statistically significant differences in P2 amplitudes. An age dependence of the P2 amplitudes was discovered inasmuch as healthy individuals under 25 years and over 55 are--with high statistical significance--apt to show higher P2 amplitudes than healthy individuals in the remaining life span.

Adolescent↗
PubMed2005

Off-ramps and on-ramps: keeping talented women on the road to success.

Most professional women step off the career fast track at some point. With children to raise, elderly parents to care for, and other pulls on their time, these women are confronted with one off-ramp after another. When they feel pushed at the same time by long hours and unsatisfying work, the decision to leave becomes even easier. But woe to the woman who intends for that exit to be temporary. The on-ramps for professional women to get back on track are few and far between, the authors confirm. Their new survey research reveals for the first time the extent of the problem--what percentage of highly qualified women leave work and for how long, what obstacles they face coming back, and what price they pay for their time-outs. And what are the implications for corporate America? One thing at least seems clear: As market and economic factors align in ways guaranteed to make talent constraints and skill shortages huge issues again, employers must learn to reverse this brain drain. Like it or not, large numbers of highly qualified, committed women need to take time out of the workplace. The trick is to help them maintain connections that will allow them to reenter the workforce without being marginalized for the rest of their lives. Strategies for building such connections include creating reduced-hour jobs, providing flexibility in the workday and in the arc of a career, removing the stigma of taking time off, refusing to burn bridges, offering outlets for altruism, and nurturing women's ambition.

Career Mobility↗
PubMed1979

Influences of an analog of the neuropeptide ACTH 4--9 on mentally retarded adults.

In a double-blind procedure, 24 mentally retarded adults received 0 mg, 5mg, or 20 mg of an analog of the neuropeptide ACTH 4--9. Following treatment with peptide, the subjects were given the Trails B Test (from the Halstead-Reitan Neuropsychological Battery), the Peabody Picture Vocabulary test, the Benton Visual Retention Test, a concept-formation task, and a standard orienting sequence. The results of the behavioral tests suggested that attentional processes were enhanced in subjects treated with the peptide. The present study, in conjunction with another investigation using the neuropeptide ACTH/MSH 4--10 (Sandman, George, Walker, Nolan & Kastin, 1976), indicates that attentional deficits in mentally retarded adults, traditionally assumed to be irreversible, may be influenced by treatment with fragments of the neuropeptides ACTH and MSH.

Adrenocorticotropic Hormone↗
PubMed1990

Dietary acetyl-L-carnitine improves spatial behaviour of old rats.

Acetyl-L-carnitine was given to aging rats to determine the extent to which it changed age-related impairments in several different behaviours. One group of rats was given acetyl-L-carnitine, 80 mg/day, beginning at 16 months of age. A second group of rats was housed and treated identically, except that no drug was administered. At 22 months of age, both groups of rats began a series of behavioural tests, along with a group of young rats, four months of age. The tests included: place learning on a circular platform, probe reversal of place learning on a circular platform, two choice simultaneous spatial discrimination in the stem of a T-maze spatial alternation in the arms of a T-maze, and sensory-motor behaviour (initiation of walking, turning in an alley, walking on a square, round, and rectangular bridge, turning on an inclined grid, holding on to a wire, light-dark preference). The tasks varied in their sensitivity to age-related impairments. These data indicate that long-term therapy with acetyl-L-carnitine attenuates certain age-related cognitive deficits and may have a beneficial effect on longevity.

Acetylcarnitine↗