Visual search for singleton feature targets within and across feature dimensions

Three experiments investigated visual search for singleton feature targets. The critical dimension on which the target differed from the nontargets was either known in advance or unknown—that is, the critical difference varied eitherwithin a dimension oracross dimensions. Previous work (Treisman, 1988) had shown that, while the search reaction time (RT) functions were flat in both conditions, there was an intercept cost for the cross-dimension condition. Experiment 1 examined whether this cost would disappear when responses could be based on the detection ofany (target—nontarget) difference in the display (by requiring a “heterogeneity/homogeneity” decision). The cost remained. This argues that pop-out requires (or involves) knowledge of the particular dimension in which an odd-one-out target differs from the nontargets; furthermore, that knowledge is acquired through the elimination of dimensions not containing a target. In Experiment 2, the subjects had to eliminate (or ignore) one potential source of difference in order to give a positive response (displays could contain a “noncritical” difference requiring a negative response). The result was a comparatively large cost in the within-dimension (positive) condition. This can be taken to indicate that popout as such does not make available information as to the particular feature value in which the target differs from the nontargets. Experiment 3 examined whether search priorities can be biased in accordance with advance knowledge of the likely source of difference. The subjects were found to have a high degree of top-down control over what particular dimension to assign priority of checking to. The implication of the results for models of visual search and selection are discussed.     

A measure of relational competence for community-dwelling elderly

A measure of relational competence was developed to assess the skills necessary for peer friendship development among the elderly. Participants were required to respond to a series of social problem vignettes that were constructed to tap empathy, assertion, and role-taking skills. Validation data were collected as part of a larger project designed to establish indigenous, elderly peer-support telephone dyads among low-income, community-dwelling elderly women. Results indicated that the measure of relational competence was related to initial friendship formation, telephone conversational skills, and rated social competence as determined by judges' ratings of 2 telephone conversations between participants and staff members. The research illustrates the usefulness of moving away from trait conceptions of social competence to a more focused consideration of particular task demands and the skills needed to solve age-linked social problems.     

Perspective taking, pictures, and the blind

Congenitally blind, late blind, and blindfolded sighted controls attempted a Piagetian perspective-taking (three-mountain) task. Piaget used the term perspective to mean point of view (Piaget & Inhelder, 1967, p. 210), and the present usage does not imply linear perspective. Subjects used raised-line drawings to depict alternative points of view of an array of three geometric solid forms (cube, cone, and ball). They then identified the point of view of raised-line drawings. The effect of visual status on accuracy was nonsignificant for both response measures. Using alternating vision of the array and drawings, sighted subjects in a control condition performed like the congenitally blind. However, congenitally blind individuals did require more time than the other subjects for the perspective-taking task. In an additional experiment, no difference was found between the three groups in the accuracy or speed of tactile shape matching. The results suggest that visual imagery and visual experience are not necessary for tactile perspective taking.     

Influence of visual guidance on braille recognition: Low lighting also helps touch

This study was an attempt to clarify the mechanisms responsible for the benefits of visual guidance in tactual braille recognition. Subjects touched +90° tilted braille under normal room lighting, or with low lighting, with or without visual guidance. Both visual information about finger angle and spatial reference information were manipulated with stained glass and light-emitting diodes. The provision of visual information about finger angle alone was no help to braille recognition, and performance was low. Adding visual spatial reference information to vision of finger angle raised performance. However, recognition accuracy was also substantially improved by low lighting. The benefits of darkness for haptics did not generalize to the reading of upright, two-letter braille words. It was proposed that extraneous visual information may distract sighted subjects in haptic tasks that require mental rotation of visual images.     

Mechanisms in the haptic horizontal-vertical illusion: Evidence from sighted and blind subjects

The haptic horizontal-vertical illusion was studied in two experiments. In Experiment 1, the illusion was relatively weak in sighted subjects and depended on stimulus size and the nature of the figure, that is, whether the pattern was an inverted-T or L shape. Experiment 2 compared early blind and late blind subjects. The illusion was present for an inverted-T figure but absent for an L figure in late blind subjects. However, the early blind subjects treated both the L and T figures as similar and showed the illusion to both. These results support the idea that visual experience may alter haptic judgments in sighted and late blind subjects.     

Response biases and the relation between negative life events and psychological symptoms

This research was an investigation of whether reporting biases can account for the correlation between negative life events (as measured via life events questionnaires) and subclinical psychological symptoms. Subjects completed two life events scales, a measure of psychological symptoms, a measure of depression, and a measure of social desirability. Friends were asked to report about life events experienced by the subjects. No evidence was found for a subject reporting bias associated with social desirability, depression, or symptoms. In fact, for one of the life events scales, depression was significantly associated with a higher rate of agreement between subjects and friends as to which negative events occurred to subjects. Moreover, there were significant correlations between symptom and depression measures and life events measures that were free of subject-reporting biases (subjects' negative life events reported by both subjects and their significant others, as well as subjects' negative life events as reported by significant others alone). These data suggest that response biases may not be able to account for the relation between negative events and psychological symptoms. Thus the hypothesis that negative life events play a significant role in symptom development remains plausible.     

Grammatical constraints on phonological encoding in speech production

To better understand the influence of grammatical encoding on the retrieval and encoding of phonological word-form information during speech production, we examine how grammatical class constraints influence the activation of phonological neighbors (words phonologically related to the target—e.g., MOON, TWO for target TUNE). Specifically, we compare how neighbors that share a target’s grammatical category (here, nouns) influence its planning and retrieval, assessed by picture naming latencies, and phonetic encoding, assessed by word productions in picture names, when grammatical constraints are strong (in sentence contexts) versus weak (bare naming). Within-category (noun) neighbors influenced planning time and phonetic encoding more strongly in sentence contexts. This suggests that grammatical encoding constrains phonological processing; the influence of phonological neighbors is grammatically dependent. Moreover, effects on planning times could not fully account for phonetic effects, suggesting that phonological interaction affects articulation after speech onset. These results support production theories integrating grammatical, phonological, and phonetic processes.     

Co-occurring anxiety influences patterns of brain activity in depression

Brain activation associated with anhedonic depression and co-occurring anxious arousal and anxious apprehension was measured by fMRI during performance of an emotion word Stroop task. Consistent with EEG findings, depression was associated with rightward frontal lateralization in the dorsolateral prefrontal cortex (DLPFC), but only when anxious arousal was elevated and anxious apprehension was low. Activity in the right inferior frontal gyrus (IFG) was also reduced for depression under the same conditions. In contrast, depression was associated with more activity in the anterior cingulate cortex (dorsal ACC and rostral ACC) and the bilateral amygdala. Results imply that depression, particularly when accompanied by anxious arousal, may result in a failure to implement top-down processing by appropriate brain regions (left DLPFC, right IFG) due to increased activation in regions associated with responding to emotionally salient information (right DLPFC, amygdala).