Spatial frequencies in short-term memory for faces: A test of three frequency-dependent hypotheses

Spatial frequency manipulations have been shown to have significant utility in ascertaining the various types of information that might be important in object identification and recognition tasks. This utility suggests that, given some mapping between ranges of spatial frequencies and different types of psychological information, it should be possible to examine the roles of these different types of psychological information by way of spatial frequency manipulations. One potential problem, however, is that there is no well-specified, unambiguous mapping between the distinctions in the frequency domain and the distinctions in the informational domain. Three experiments provide tests of three general hypotheses regarding the ways in which different spatial frequencies might map to different information in facial perception and memory tasks: (1) the low-frequency dominance hypothesis, which proposes that low-frequency information should be superior (to high-frequency information) as a cue to perception and memory; (2) the distinct informational roles hypothesis, which holds that high spatial frequencies should carry featural information while low spatial frequencies should carry information about the configuration of those features; and (3) the task-dependent information hypothesis, which suggests that high-frequency information should be best suited to discrimination tasks while low-frequency information should be best suited for recognition tasks. Results generally contradict the first two of these hypotheses, while providing support for the third. Implications with regard to the various issues related to the mapping between spatial frequencies and the informational content of faces, as well as the need to consider important interactions among perceptual and memory processes, are discussed.     

Centrality of women's multiple roles: beneficial and detrimental consequences for psychological well-being

Theorists have proposed that greater centrality (personal importance) of a social role is associated with better psychological well-being but that role centrality exacerbates the negative effects of stress in that same social role on well-being. The present study found evidence to support both hypotheses in a sample of 296 women who simultaneously occupied the roles of parent care provider, mother, wife, and employee. Greater centrality of all four roles was related to better psychological well-being. As predicted, wife centrality exacerbated the effects of wife stress on life satisfaction, and employee centrality exacerbated the effects of employee stress on depressive symptoms. Contrary to prediction, centrality of the mother role buffered women from the negative effects of mother stress on depressive symptoms. These findings point to an aspect of role identity that can benefit well-being but that has complex effects in the context of role stress.     

An analysis of air-stepping in normal infant vervet monkeys

Limb movements during air-stepping were analyzed in three neonatal vervet monkeys over a three-week period. The movements had similar temporal organization both across animals and across time. For example, the duration of both the hind and the forelimb cycle equaled about 500 ms, with hind limb return strokes lasting much longer than the hind limb power strokes. Furthermore, there were clear indications of both intra- and interlimb coordination. Specifically, all the joints of a limb tended to flex and extend simultaneously, and contralateral and ipsilateral limb pairs had an average phase relationship of approximately 50% of cycle duration. Despite a qualitative similarity between limb movements during air-stepping in the neonates and overground locomotion in older animals, there were notable differences both in temporal relationships and joint displacement patterns. Finally, there appeared to be important similarities between air-stepping in these monkeys and stepping in newborn humans. Most notably, both tended to disappear after a limited period. The implications of these similarities, as well as the overall results, are discussed in relation to the understanding of the development of locomotor behavior in human and nonhuman primates, using approaches based both upon the hard-wired and dynamic models.     

Parallel Processing Response Times and Experimental Determination of the Stopping Rule

It was formerly demonstrated that virtually all reasonable exhaustive serial models, and a more constrained set of exhaustive parallel models, cannot predict critical effects associated with self-terminating models. The present investigation greatly generalizes the parallel class of models covered by similar "impossibility" theorems. Specifically, we prove that if an exhaustive parallel model is not super capacity, and if targets are processed at least as fast as non-targets, then it cannot predict such (self-terminating) effects. Such effects are ubiquitous in the experimental literature, offering strong confirmation for self-terminating processing. Copyright 1997 Academic Press. Copyright 1997 Academic Press     

Serial and within-stage independent parallel model equivalence on the minimum completion time

A set of functional equations is investigated that, when satisfied, yields equivalence on the minimum completion time between serial models and parallel models having the property of within-stage independence. Within these classes of models, it is shown that any parallel model is equivalent to a serial model, but not any serial model is equivalent to a parallel model. The necessary and sufficient conditions for a serial model to have an equivalent parallel counterpart are observed and then two sufficient conditions on the survivor functions that produce this result are exhibited. A number of examples satisfying the various theorems are discussed and a special case leading to an extension of a property of exponential distributions is derived.     

Search reaction time for single targets in multiletter stimuli with brief visual displays

The same set of Ss was run In an LT (single late target letter followed an earher multiletter display) and an ET (single early target preceded a later multiletter display) condition. On one-half the trials, the multiletter set included the target. and on the other half, the target was absent. The task of S was to push the “yes” (“no”) button if the target was present (absent), and reaction times were recorded. The most plausible processing model assumed that LT comparisons took place in a verbal-acoustic store and that ET comparisons took place in a visual store. It further assumed that processing within these stores was self-terminating, with rates that differed on “same” and “different” comparisons and which changed as the multiletter set increased. Classes of serial and parallel models that are falsified or supported by the present and similar data are discussed.     

Children's comprehension of comparative forms

Children aged from 3.5 to 5.5 years were tested on their comprehension of the terms taller, shorter, more, and less in five types of sentences: truncated, explicit standard, expanded explicit standard, two-dimensional second-clause subject noun, and two-dimensional second-clause subject pronoun. Many childen performed poorly on less and shorter in truncated sentences; the presence of explicit comparative cues did not improve these children's performance. Children who performed perfectly on truncated sentences still had difficulty understanding two-dimensional comparisons, especially those with a second-clause subject pronoun. These children interpreted only the first clause of the second-clause subject pronoun sentences. The results suggest that many children are capable of understanding two-dimensional comparisons, but perform poorly on the second-clause subject pronoun sentences because of uncertainty about the referent of the pronoun.     

Further experiments on the olfactory thresholds of pure chemical substances, using the “Sniff-Bottle method”

“Sniff-Bottle” method of determining olfactory thresholds under conditions of adaptation to a second olfactory stimulus, as described by Cheesman and Mayne (1953), has been further developed. Their study was limited to the mutual adaptation effects of three substances. The original matrix of nine quantities, described as degrees of community of odour property, has been revised and extended to include a fourth stimulus-substance. It is suggested that the matrix now obtained shows a definite pattern characteristic of consistent mutual relationships between the substances. A number of shortcomings in the original technique are discussed, and the appropriate emendations described.     

Influence of correlated visual cues on auditory signal detection

Two experiments investigated the effects on auditory signal detection of introducing visual cues that were partially correlated with the signal events. The results were analyzed in terms of a detection model that assumes that such cue-signal correlations will not affect sensitivity, but will instead cause the subject to develop separate response biases for each cue. The model specifies a functional relationship between the asymptotic values of these cuecontingent biases. The overall results of the experiments supported the detection assumptions of the model and the general bias learning assumption, but indicated a more complex learning process than that specified by the model.