Illusory conjunctions and the cerebral hemispheres

Two visual half-field experiments tested Moscovitch’s (1979) proposition that cerebral asymmetry does not concern the earliest perceptual stages but only later processing. Subjects were briefly shown displays that included one (Experiment 1) or two (Experiment 2) types of forms differing in size and which, according to previous evidence, might lead to opposite laterality effects. Laterality effects were assessed for correct detections and for illusory conjunctions, both in terms of raw detection scores and in terms of perceptual discriminability (dr scores). In Experiment 1, displays included either rectangles or triangles. In the first case, the target was a cross; in the second case, it was a Star of David. A hemifield x size interaction was observed both on correct detections and on associated discriminability. Yet, no such interaction was obtained for illusory conjunctions or for associated d’ scores. In Experiment 2, the two types of forms were presented simultaneously, with the small ones either inside or outside the large ones. No laterality effects were observed. Some implications of these data for both hemispheric asymmetry and feature integration issues are discussed. The results suggest that early preattentive processes of feature extraction are not lateralized, whereas some integrative mechanisms, such as Treisman’s (1988) focal attention, may operate differently in the two hemispheres.     

Distractor clustering enhances detection speed and accuracy during selective listening

The effects of distractor clustering on target detection were examined in two experiments in which subjects attended to binaural tone bursts of one frequency while ignoring distracting tones of two competing frequencies. The subjects pressed a button in response to occasional target tones of longer duration (Experiment 1) or increased loudness (Experiment 2). In evenly spaced conditions, attended and distractor frequencies differed by 6 and 12 semitones, respectively (e.g., 2096-Hz targets vs. 1482- and 1048-Hz distractors). In clustered conditions, distractor frequencies were grouped; attended tones differed from the distractors by 6 and 7 semitones, respectively (e.g., 2096-Hz targets vs. 1482- and 1400-Hz distractors). The tones were presented in randomized sequences at fixed or random stimulus onset asynchronies (SOAs). In both experiments, clustering of the unattended frequencies improved the detectability of targets and speeded target reaction times, Similar effects were found at fixed and variable SO As. Results from the analysis of stimulus sequence suggest that clustering improved performance primarily by reducing the interference caused by distractors that immediately preceded the target.     

Linguistic Phenomena and Language Selection in the REM Dreams of German-English Bilinguals

Sixteen German-English bilinguals were studied in a sleep laboratory for four nonconsecutive nights each. Half were native English speakers living in Zürich, and half native German speakers living in Atlanta. Presleep thought samples were solicited each evening and REM dream reports each night; subjects judged the waking appropriateness of their imagined speech and language phenomena, and also identified waking sources of their dream imagery, the following mornings. Incidences of dreaming and of speech therein generally were similar to those of monolinguals. Whether sessions were conducted in German (two nights) or English (two nights) did directly influence language selection in subjects' dreams. Judged appropriateness of language selection to imagined events was very high for thought samples, and high for REM dreams. Sources for thought samples were generally consonant with the language dominant at study site; for REM dreams this relationship was considerably weaker. Judged waking appropriateness to imagined situations was more strongly related to language selection than was the language reference of the supposed sources of those situations.     

A Coming-of-Age for Research on Interpersonal Perception

ABSTRACT Research on accuracy and consensus in interpersonal perception has become a major topic in the social sciences. Key methodological issues in this research are research design, statistical measures of agreement, unit of analysis, and data aggregation. I discuss the twelve articles devoted to these topics in this special issue in terms of moderators of agreement, the weighted average model of consensus and accuracy (Kenny, 1991), and methodological innovations.     

The Influence of Goal Orientation on Task Performance: A Substantively Meaningful Suppressor Variable1

The present study investigated the relationship between performance goal orientation and performance on a complex task. It was hypothesized that cognitive interference would mediate this relationship. In addition, it was hypothesized that cognitive ability would moderate the relationship between cognitive interference and task performance. A three-variable suppressor relationship indicated that, although the direct effect of performance goal orientation on performance was one that produced better performance, the indirect effect of performance goal orientation indicated that performance orientations were associated with increases in cognitive interference, and these increases in cognitive interference were associated with poorer performance. Thus, the beneficial aspect of performance goal orientation (i. e., the direct effect) was counterbalanced by the dysfunctional aspects of performance goal orientation (i. e., the associated increase in cognitive interference). Support was also found for the proposed moderation of ability on the cognitive interference-task performance relationship for final, but not initial performance. The results are interpreted in light of recent discussions regarding the influence of goal orientation on task performance and cognitive interference.     

The effect of maternal depression on maternal ratings of child behavior

There have been continuing concerns about the extent to which maternal depression may influence maternal reports of child behavior. To examine this issue, a series of structural equation models of the relationships between maternal depression and errors in maternal reports of child behavior was proposed and tested. These models assumed that (a) maternal depression was unrelated to maternal reporting behavior; (b) maternal depression causally influenced maternal reporting accuracy; (c) maternal depression was correlated with reporting accuracy. These models were fitted to data on maternal depression and multipleinformant (mother, teacher, child) reports of conduct disorder and attention deficit behaviors for a birth cohort of 12 and 13yearold New Zealand children. The results of model fitting suggested the presence of small to moderate correlations (@#@ r=+.13 to+.40) between maternal depression and maternal reporting errors, indicating the presence of a tendency for increasing maternal depression to be associated with a tendency for mothers to overreport child behavior problems. However, independently of any effects of maternal depression on maternal reporting errors there was evidence of small but significant associations (r=.10 to .17; p<.05)between maternal depression and child conduct disorder and attention deficit behaviors.This research was funded by grants from the Health Research Council of New Zealand.     

Spatial and Selective Attention in the Cerebral Hemispheres in Depression, Mania, and Schizophrenia

Two tachistoscopic tests examining distinct aspects of attention were administered to normal subjects and patients with depression, mania, and schizophrenia. The first examined spatial attentional bias using happy-sad chimeric faces, known to elicit a perceptual bias to the left side of space in normal right-handers provided the right cerebral hemisphere is intact. The second used a lateralized version of the Stroop task, a traditional test of selective attention. Normals showed the expected leftward perceptual bias but showed equivalent susceptibility to the Stroop effect in both visual fields. As previously demonstrated with chimeric faces viewed in free vision, depression and mania were associated with weak and strong biases respectively with schizophrenics showing no bias to either side of space. The relationship between perceptual bias, as assessed by reaction time and absolute performance and the Stroop effect, showed differences according to diagnosis. This may be interpreted as evidence for the dissociability of attentional processes as well as lateralized differences in the pattern of cerebral activation in affective disorders and schizophrenia. The independence of performance variables on these tests in the schizophrenic group points to severe neuropsychological dysfunction.     

Gender differences in self-evaluations of information about current affairs

This study examines how gender is related to self-evaluations of information to discuss current social and political issues. The sample is one of predominantly white (96%) college graduates. Using alumni samples, we look at how members of four classes that span 20 years evaluate their knowledge to hold conversations on a variety of public affairs issues ranging from the Strategic Defense Initiative to government funding of abortion. We find gender differences, with men perceiving themselves more knowledgeable in conversations and women less so. We raise the possibility that they are “doing gender.” The implications of these findings are explored.