Is 26 + 26 smaller than 24 + 28? Estimating the approximate magnitude of repeated versus different numbers

It has recently been suggested that regardless of the dimension at hand (i.e., numerosity, length, time), similar operational mechanisms are involved in the comparison process based on approximate magnitude representation. One piece of evidence for this hypothesis lies in the presence of similar behavioral effects for any comparison (i.e., the distance effect). In the case of length comparison, the comparison process can be biased by summation toward either an underestimation or an overestimation: The sum of equal-size stimuli is underestimated, whereas the sum of different-size stimuli is overestimated. Relying on the hypothesis that similar operational mechanisms underlie the comparison process of any magnitude, we aim at extending these findings to another magnitude dimension. A number comparison task with digit numbers was used in the two experiments reported presently. The objective was to investigate whether summation also biases magnitude representation of numerical and symbolic information. The results provided evidence that the summation bias can also apply to numerical magnitude comparison, since the sum of repeated numbers (26 + 26) was underestimated whereas the sum of different numbers (24 + 28) was overestimated. We propose that these effects could be accounted for by a heuristic linking cognitive effort and magnitude estimation.     

Atypical EEG power correlates with indiscriminately friendly behavior in internationally adopted children

While effects of institutional care on behavioral development have been studied extensively, effects on neural systems underlying these socioemotional and attention deficits are only beginning to be examined. The current study assessed electroencephalogram (EEG) power in 18-month-old internationally adopted, postinstitutionalized children (n = 37) and comparison groups of nonadopted children (n = 47) and children internationally adopted from foster care (n = 39). For their age, postinstitutionalized children had an atypical EEG power distribution, with relative power concentrated in lower frequency bands compared with nonadopted children. Both internationally adopted groups had lower absolute alpha power than nonadopted children. EEG power was not related to growth at adoption or to global cognitive ability. Atypical EEG power distribution at 18 months predicted indiscriminate friendliness and poorer inhibitory control at 36 months. Both postinstitutionalized and foster care children were more likely than nonadopted children to exhibit indiscriminate friendliness. Results are consistent with a cortical hypoactivation model of the effects of early deprivation on neural development and provide initial evidence associating this atypical EEG pattern with indiscriminate friendliness. Outcomes observed in the foster care children raise questions about the specificity of institutional rearing as a risk factor and emphasize the need for broader consideration of the effects of early deprivation and disruptions in care.     

Efficiency of visual selective attention is related to the type of target

Lavie and Cox (1997, Psychological Science, 8, 395) suggested that stimuli outside the focus of attention can have more distracting effects when the task requires less attention than when it requires more. This idea provides an explanation for the proposed dissociation found between two forms of attentional control (Folk & Remington, 1998, Journal of Experimental Psychology: Human Perception and Performance, 24, 847). This proposal was based on a red (green) distractor that captured attention when a red (green) target was used, but not when a green (red) target was used, and the further result that, if there were no distractor, reaction times were faster than with either type of distractor. We tested whether a target that requires serial search would eliminate the dissociation. With the same targets used by Folk and Remington (ones that can be found with parallel search), we also obtained a dissociation. However, with the serial-search targets, dissociation was not found. Our interpretation is that the dissociation represents two forms of the same attentional process.     

Analog versus discrete shifts of attention across the visual field

Summary Two discrimination experiments were run to investigate analog versus discrete properties of a shift of visual spatial attention. Central cuing was used in Experiment 1, whereas peripheral cuing was used in Experiment 2. Presentation of a probe stimulus between fixation and the target (Distance 1), opposite fixation from the target (Distance 3), or away from an imaginary line running from the target through fixation (Distance 2) permitted a fine-grained analysis of attention at those loci across target-probe delays. D-prime analyses in both experiments suggest that attention is shifted in a discrete manner between locations. Sensitivity to probes was generally greater when the probe was aligned with the target and fixation, with Distance 3 equal to Distance 1, than when it was away (at Distance 2). Analysis of sensitivity to targets across cue-probe delays suggests that attention was directed to the probe upon its appearance.This research was supported by a grant from the National Science Foundation (BNS87-20421).     

The first glimpse determines the perception of an ambiguous figure

The ambiguous rat-man figure was tachistoscopically presented to 36 subjects in successive segments to test the hypothesis that the starting segment would determine the perception of the figure. Starting segments were selected which were expected to produce the perception of a rat, a man, or either a rat or man. The remaining segments came from figures evaluated in a preliminary study. The selected figures differed in drawn bias and tended to be seen as a rat, a man, or either a rat or a man. The three starting segments were combined factorially with the three levels of drawn bias of the remaining segments. The effect of the starting segment was significant; the effect of drawn bias was not. A further experiment showed that presentation of the rat vs. man starting segments by themselves did not produce a reliable difference. The results support a constructive model of form perception in which the stimulus material first presented establishes a hypothesis which is used to interpret the remaining material.     

Differentiating falsely recognized faces from incompletely remembered faces

This study describes an experimental method for determining whether people who recognize a face containing both some target features and some new features are falsely recognizing the face or whether they are incompletely remembering it. Twenty min. after studying a target face either one time or a third time, 136 participants were instructed to examine six test faces similar to the target and to select two test faces sharing only target features and no unstudied features. The likelihood of selecting two test faces sharing four target features and no incorrect features was significantly greater than chance only for the 67 participants who studied the target three times. Because the two faces selected as containing only target features did not share any unstudied features, they were not falsely recognized; instead, they were indicative of correct but incomplete memory for the thrice-studied target.     

Attention effects of moving and stationary single-element and multiple-element precues: Limits of automaticity

A multiple-element precue (MEP), in which one unique element defines the actual precue, results in efficient precuing for identification of a target. The time course for identification in this case is similar to that for a central precue, even though it is presented peripherally (Chastain, 1996; Chastain & Cheal, in press). Five experiments were conducted to gain further information on the function of MEPs and to question what advantage prior knowledge of the precue may give. In Experiments 1 and 2, it was shown that for “pop-out” features, accuracy of identification of a target was higher if the precue type was known in advance. In contrast, as shown in Experiments 3, 4, and 5, when the precue was defined by apparent motion, there was no difference in accuracy due to advanced knowledge of the precue. Further, accuracy was considerably better for motion precues than for stationary precues.     

Does Manning Men's Studies Emasculate Women's Studies?

Defends “The New Men's Studies: From Feminist Theory to Gender Scholarship” (Hypatia 2:1, Winter 1987) against what is argued are Mary Libertin's misreadings. The argument for men's studies is logically independent of though related to the debate about essentialism in women's studies. Men's studies studies men in and as particular groups. Intellectual should not be equated with institutional autonomy. The feminist study of men should be supported by feminist scholars.     

Word-to-letter inhibition: Word-inferiority and other interference effects

Four experiments were run to determine whether the interactive activation model would more accurately reflect the effect of context in letter perception by including word-to-letter inhibition resulting from word-to-word inhibition produced when multiple word units become active. The first three experiments found less accurate target letter discrimination in word than in nonword strings when a string was altered halfway through the exposure through adding or dropping a nontarget letter. The alteration changed a word to a different word or a nonword to a different nonword. Unaltered strings produced the typical word-superiority effect. The last experiment found an inverse relationship between target discrimination performance and the number of word substrings contained in each of a set of word quadrigrams that were individually exposed.