Canadian journal of psychology最新文献

In immediate ordered recall, recency is the improved recall of the last item of a presentation, and the modality effect is the advantage for an acoustic presentation over a subvocalized visual presentation, primarily occurring at the last serial position. Experiment 1 tested grouped presentations. There was a modality effect for the first item of the last group, even though that item was at the third-to-last or fourth-to-last serial position. In Experiment 2, for vocalized presentations of syllables ending in a, recency was larger for staccato speech than legato speech; for subvocalized presentations, there was a substantial recency for the legato style. In Experiment 3, recency was larger for a set of syllables ending in ATE than for a set of syllables ending in AME. These results suggest that recency cannot be explained by the existence of a fixed-capacity store, auxiliary to the auditory short-term store, that retains only some types of presentations. It is suggested instead that recency might reflect an auxiliary method of using the information in the auditory short-term store.

Fifty-three left-handers with consistent left-hand preferences (CLH), 65 left-handers with inconsistent hand preferences (ILH), and 57 right-handers (RH) were given unimanual and bimanual performance tests involving skill, speed, and strength as well as tests of articulatory speed and verbal fluency. Contrary to claims in the current literature (Ponton, 1987), CLHs and ILHs do not differ in quality and speed of performance, but, in some tests, they do show asymmetries in opposite directions. Thus, when left-handers are treated as a combined group, the faulty impression of a lack of between-hand asymmetries arises. The results suggest that a distinction between CLHs and ILHs yields subgroups with reliably different and distinctive performance patterns which are not trivially attributable to differences in strength of lateralization. CLHs behave much like mirror image RHs, whereas ILHs show a dissociation between strength, fine manual skill, attentional asymmetries.

In contemporary debates about laterality in animals, the parrot (Psittaciformes) is often cited as an exemplar--possibly unique--of laterality in limb function at the population level comparable in kind and strength to handedness in man. This conclusion rests on just two reports (Friedman & Davis, 1938; Rogers, 1980) that most species of parrots are left-footed, that is, that they preferentially perch on the right foot and hold food with the left. In fact, speculation about and scientific study of laterality in parrots go well beyond these two investigations. The question itself dates from at least the 17th century, after which, beginning in the 1860s, it became the subject of broad interest and debate. In our own time, it also has continued to occupy the attention of at least a small number of ornithologists and field biologists whose work, like that of their predecessors, is not cited in the current neuropsychological literature on this topic. To fill out the historical as well as contemporary record for consideration by neuropsychologists today, these other observations and theoretical analyses are reviewed, and new questions about laterality in parrots raised by this work are presented.

We presented 7- to 9-month-old infants with repetitions of three- or four-tone sequences characterized by a particular rhythmic structure. We then evaluated their detection of changes in rhythmic structure in the context of randomly presented variations in tempo (rate) and frequency. Infants successfully differentiated between three-tones sequences with 1, 2 (X XX) and 2, 1 (XX X) structure as well as four-tone sequences with 2, 2 (XX XX) and 3, 1 (XXX X) structure. In other tasks, they indicated their ability to discriminate between contrasting tempos in the context of frequency variations. We conclude, then, that infants can categorize auditory sequences on the basis of rhythm and also on the basis of tempo.

The nature of the evidence on the role played by early stimulation history in perceptual development related to an appreciation of intermodal attributes involving space and time is reviewed. In conjunction with this analysis, an examination was undertaken of the effect of early visual deprivation on the ability of dark- (DR) and light-reared (LR) rats to learn discriminations involving location of sounds or lights and to abstract the intersensory correspondence involved from the initial modality-specific training. Visually inexperienced DR rats were somewhat slower to acquire a discrimination involving the location of visual events under some stimulus/response arrangements. More importantly, such animals were not as effective as their visually experienced LR counterparts in demonstrating cross-modal transfer (CMT) to signals in a new modality. The present study also revealed that CMT involving location of signals was less salient than CMT of duration information in rats regardless of their rearing condition. Finally, findings are discussed more generally, providing contextual information that bears on issues related to parallel cognitive functions in rats and human neonates and on the role of early visual experience in the ontogeny of intersensory perceptual competence in mammals.

Visual acuity, the most basic measure of developing pattern vision in human infants, has been used extensively for detecting anomalies of vision and oculomotor coordination. In the past 10 years much has been learned about the development of two hyperacuities, namely, vernier acuity and stereoacuity. These two acuities become superior to grating acuity after the third month and remain so throughout life. Compared to females, males show slower development of stereopsis and vernier acuity, but not grating acuity, during the third through sixth months. We have suggested that this may result from the neurotrophic effects of the early pulse of testosterone found in males. Measures of vernier acuity have proven effective in detecting meridional amblyopia in older children who had significant astigmatism in the first year and subsequently lost it. The susceptible period for acquiring meridional amblyopia extends from the second half of the first year to at least the end of the second year. Deviations from the typical oblique effect (equal acuity for vertical and horizontal edges; equal, but lower, acuity for left oblique and right oblique) may result from uncorrected astigmatism early in life.

For many years the mechanisms that underlie normal and abnormal development of visual perception in human infants have been explored in anatomical and physiological studies on two species of frontal-eyed mammals, namely, cats and, to a lesser extent, monkeys. The unstated assumption underlying the investigations on cats is that despite substantial differences in the organization of the visual pathways of cats and humans, as well as quantitative differences in their perceptual abilities, principles of development established in the former also apply to humans. This review examines the extent to which this assumption may be valid. Following a review of certain anatomical peculiarities of the cat visual system, several of the differences as well as the parallels between the perceptual abilities of cats and humans are summarized. The latter similarities, as well as the larger number of parallels between the two species that can be drawn during development, attest to the validity of the choice of the cat for study of the mechanisms that underlie human visual development.

The purpose of this paper is to discuss the relationship between the haptic and visual systems during infant's bimodal interaction with objects. Four general topics are discussed: the role of exploratory activity in perception, the specific ways in which the two systems are related during exploration, developments over age in the relationship between the systems, and the impact of the organism/environment relationship on these developments.