The Effect of Looking Behavior on Perceptions of a Communicator's Credibility1

A courtroom simulation technique was employed to examine the effects of a communicator's looking behavior on observers' perceptions of his credibility. Half of the subjects heard testimony presented on behalf of a defendent by a witness (one of three confederates) who was visually presented as either looking directly toward the target of his communication (gaze maintenance) or slightly downward (gaze aversion) while testifying. The other half of the subjects merely heard the audio portion of the testimony. The results indicated that witnesses who averted their gaze were perceived to be less credible and, ultimately, the defendant for whom they testified was judged as more likely to be guilty. These results are discussed in terms of their implications for research concerned with the communicative effects of visual behavior.     

Attention demands of visual search

The relation between attention demand and the number of items in the array (array size) was investigated by engaging subjects in a primary search task and measuring spare capacity at different points in time, with a secondary tone task that occurred randomly on half of the trials. The major variables in both tasks were array size 14, 8, or 12 letters and stimulus onset asynchrony (SOA: ?400, ?200, 0, 200, 400, and 600 msec. Subjects were able to perform the tasks quite independently, and me, st of the interference that resulted from nonindependence appeared in tone-task performance. Theamount of interference (i.e., maximum tone reaction time) was independent of array size, but theduration of interference (li.e., the number of SOAs at which tone reaction time was elevated) increased with array size. The findings were interpreted as supporting unlimited-capacity models of visual search performance.     

The role of muscle tension in “repression”

Using an active partial avoidance conditioning paradigm, muscle tension was conditioned to a verbal conditional stimulus (CS), and recall of words semantically unrelated and related to the CS was tested under conditions of three levels of induced muscle tension with 20 subjects (Ss). Results showed the expected decrease in latency of response with moderate tension for all stimuli during the pretreatment period and for the unrelated words during the posttreatment period and a significant increase in latency of response for the related words during the posttreatment period. It is suggested that if the level of muscle tension associated with the conditional response (CR) is induced in Ss, then recall of CS-related material will be inhibited or “repressed.”     

Ultrastable stimulus-response latencies: Acquisition and stimulus control

Modifications were made to Kristofferson’s (1976) response-stimulus synchronization procedure which resulted in a further reduction in the estimate of minimum S-R latency variance. Minimum variances near 50 msec² were obtained whether mean latency was 310 or 550 msec. Within this range, latency distributions were the same, symmetrical and sharp-peaked, and unlike typical RT. All responses fell within a 50-msec time window. This independence of mean latency and latency variance was present throughout acquisition. A special technique allowed isolation of the controlling stimulus for synchronization timing, and showed that subjects were able to transfer control to another modality with no loss of performance. Results are discussed in terms of support for the notion of nonvariable, internally timed delays which can be inserted in the S-R chain. These delays are easily adjustable, but, once set, are deterministic. The role of feedback in acquisition and maintenance of synchronization performance is also examined.     

Visual perseveration in normal and mentally retarded children

Visual perseveration was investigated within mentally retarded and second, fifth, and eighth grade normal children (Ns = 12 each group). Subjects matched an auditorially presented click to the onset and offset of visually presented stimuli. Time differences between visual stimulus offset and the point at which subjects reported simultaneity of the click and visual stimulus offset was assumed to reflect visual perseveration. Results showed: (a) no differences between the normal children as a function of age; (b) no difference between groups for stimuli of 100 msec. or longer duration; and (c) retarded subjects judged stimuli of 20 and 50 msec. to be of shorter duration than did normal subjects. This highly specific distinction between retarded and normal subjects suggests a difference in an early stage of perceptual processing.     

Infants' discrimination of faces by using biological motion cues

We report two experiments in which we used animated averaged faces to examine infants' ability to perceive and discriminate facial motion. The faces were generated by using the motion recorded from the faces of volunteers while they spoke. We tested infants aged 4-8 months to assess their ability to discriminate facial motion sequences (condition 1) and discriminate the faces of individuals (condition 2). Infants were habituated to one sequence with the motion of one actor speaking one phrase. Following habituation, infants were presented with the same sequence together with motion from a different actor (condition 1), or a new sequence from the same actor coupled with a new sequence from a new actor (condition 2). Infants demonstrated a significant preference for the novel actor in both experiments. These findings suggest that infants can not only discriminate complex and subtle biological motion cues but also detect invariants in such displays.     

Large sex difference in adolescents on a timed line judgment task: attentional contributors and task relationship to mathematics

Visuospatial performance, assessed with the new, group-administered Judgment of Line Angle and Position test (JLAP-13), varied with sex and mathematical competence in a group of adolescents. The JLAP-13, a low-level perceptual task, was modeled after a neuropsychological task dependent upon functioning of the posterior region of the right hemisphere [Benton et al, 1994 Contributions to Neuropsychological Assessment: A Clinical Manual (New York: Oxford University Press)]. High-school boys (N = 52) performed better than girls (N = 62), with a large effect for sex (d = 1.11). Performance increased with mathematical competence, but the sex difference did not vary significantly across different levels of mathematics coursework. On the basis of earlier work, it was predicted that male, but not female, performance in line judgment would decline with disruptions to task geometry (page frame), and that the sex difference would disappear with disruptions to geometry. These predictions were supported by a number of univariate and sex-specific analyses, although an omnibus repeated-measures analysis did not detect the predicted interaction, most likely owing to limitations in power. Thus, there is partial support for the notion that attentional predispositions or strategies may contribute to visuospatial sex differences, with males more likely than females to attend to, and rely upon, internal or external representations of task geometry. Additional support for this hypothesis may require development of new measures or experimental manipulations with more powerful geometrical disruptions.     

Symptoms versus impairment: the case for respecting DSM-IV's Criterion D

Diagnosing ADHD based primarily on symptom reports assumes that the number/frequency of symptoms is tied closely to the impairment imposed on an individual's functioning. That presumed linkage encourages diagnosis more by Diagnostic and Statistical Manual of Mental Disorders (4th ed.) style symptom lists than well-defined, psychometrically sound assessments of impairment. The current study correlated measures reflecting each construct in four separate, large-scale ADHD research samples. Average correlation between symptoms and impairment accounted for less than 10% of variance. Symptoms never predicted more than 25% of the variance in impairment. When an ADHD group was formed according to a measure of current symptoms, the sample size shrunk by 77% when a criterion-based measure of impairment was added. The partial unlinking of symptoms and impairment has implications for decisions about the diagnostic process, research criteria for participant inclusion, prevalence estimates, gender ratios, evaluation of treatment effects, service delivery, and many other issues.     

Selective attention during scene perception: Evidence from negative priming

In two experiments, we examined the role of semantic scene content in guiding attention during scene viewing. In each experiment, performance on a lexical decision task was measured following the brief presentation of a scene. The lexical decision stimulus named an object that was either present or not present in the scene. The results of Experiment 1 revealed no priming from inconsistent objects (whose identities conflicted with the scene in which they appeared), but negative priming from consistent objects. The results of Experiment 2 indicated that negative priming from consistent objects occurs only when inconsistent objects are present in the scenes. Together, the results suggest that observers are likely to attend to inconsistent objects, and that representations of consistent objects are suppressed in the presence of an inconsistent object. Furthermore, the data suggest that inconsistent objects draw attention because they are relatively difficult to identify in an inappropriate context.     

Linking Substance Use and Problem Behavior Across Three Generations

This study examined patterns of between-generation continuity in substance use from generation 1 (G1) parents to generation 2 (G2) adolescents and from G2 adult substance use and G1 substance use to generation 3 (G3) problem behavior in childhood. Structural equation modeling of prospective, longitudinal data from 808 participants, their parents, and their children showed low levels of G1 to G2 cross-generational continuity in the general tendency to use drugs. This effect was fully mediated by G2 early adolescent behavior problems. Drug-specific residual effects were observed across generations for cigarette smoking. Once established in adolescence, substance use in G2 showed stability over time. G2 substance use at age 27 significantly predicted G3 problem behavior. G1 substance use also was related to G3 problem behavior indirectly. These findings highlight the importance of interrupting intergenerational cycles of substance use and problem behavior.