Protecting threatened identity: sticking with the group by emphasizing ingroup heterogeneity

In two studies (Ns=163, 164), the authors tested the prediction that perceptions of group variability can steer and guide the way that loyalty is expressed in times of identity threat. In both studies, participants were classified as lower or higher identifiers on the basis of their scores on a group identification measure, and manipulations involved group variability perceptions (homogeneous ingroup vs. heterogeneous ingroup) and threat to the ingroup. Higher identifiers presented with a homogeneous ingroup perceived more ingroup homogeneity under threat than when there was no threat. In contrast, higher identifiers who perceived the ingroup initially as heterogeneous perceived more ingroup heterogeneity under threat than in no threat conditions. Lower identifiers perceived more ingroup heterogeneity under threat (vs. no threat) irrespective of manipulated group variability perceptions. Discussion focuses on different ways that group loyalty can be expressed in times of identity threat.     

Teacher acquisition of functional analysis methodology

The current study examined methods for training teachers to use functional analysis methods. Teachers first received written and verbal instructions detailing attention and demand conditions. They then received training that included modeling, rehearsal, and performance feedback. Finally, probes were taken during ongoing class instruction. Results indicate that teachers acquired the skills and used them in classroom settings.     

The believability of children and their interviewers' hearsay testimony: when less is more

Hearsay testimony from children's interviewers is increasingly common in sexual abuse trials, but little is known about its effects on juries. In 2 studies, the authors examined college students' perceptions of 3 types of hearsay testimony (an actual interview with a child or an adult interviewer providing either the gist of what that child had said or a verbatim account of the interview). Interviewers were rated as more accurate and truthful than the children. The interview was rated as higher quality, and children's statements, including their false statements, were sometimes rated as more believable in the interviewer gist hearsay condition. Mock jurors reacted differently to various types of hearsay testimony, and interviewer gist testimony may favor a child's case.     

Evidence of perspective-taking constraints in children's on-line reference resolution

Young children's communication has often been characterized as egocentric. Some researchers claim that the processing of language involves an initial stage that relies on egocentric heuristics, even in adults. Such an account, combined with general developmental difficulties with late-stage processes, could provide an explanation for much of children's egocentric communication. However, the experimental data reported in this article do not support such an account: In an elicited-production task, 5- to 6-year-old children were found to be sensitive to their partner's perspective. Moreover, in an on-line comprehension task, they showed sensitivity to common-ground information from the initial stages of language processing. We propose that mutual knowledge is not distinct from other knowledge relevant for language processing, and exerts early effects on processing in proportion to its salience and reliability.     

Cross-modality attentional blinks without preparatory task-set switching

When two masked targets (T1 and T2), both requiring attention, are presented within half a second of each other, report of the second target is poor, demonstrating an attentional blink (AB). Potter, Chun, Banks, and Muckenhoupt (1998) argued that all previous demonstrations of an AB occurring when one or more targets were presented outside the visual modality did not represent true AB but were, instead, artifactual, resulting from switching of task set. In the present experiments, T1 and T2 modalities were independent and varied randomly from trial to trial, allowing no useful preparatory task-set switching from T1 to T2. However, reliable ABs were observed when both targets were visual, when both targets were auditory, and cross-modally when T2s were visual. Furthermore, the ABs observed for crossmodality visual T2s showed the characteristic U-shaped pattern often found in AB experiments in which two visual targets are used—a pattern that should not be observed under task-set switching conditions. These results provide evidence that cross-modality AB can be found under conditions that do not allow useful preparatory task-set switching.     

Neuropsychological Sequelae of Subthalamic Nucleus Deep Brain Stimulation in Parkinson's Disease: A Critical Review

Neuropsychologists are increasingly involved in surgical candidacy evaluations and postoperative neurobehavioral assessments of patients with movement disorders, most notably those with disease (PD). We review here the initial studies regarding neuropsychological outcomes of deep brain stimulation (DBS) within the subthalamic nucleus (STN) for treatment of PD. Overall, these initial investigations provide preliminary support for the cognitive and neurobehavioral safety of STN DBS. Improvements in self-reported symptoms of depression and diminished verbal fluency were the most common findings, whereas changes in global cognitive abilities, memory, attention, and frontal/executive functions were inconsistent and most often described as nominal and/or transient. The generalizability of this literature is hindered by several methodological limitations, including small samples and the absence of appropriate control participants. The clinical and theoretical implications of these initial studies are highlighted and recommendations are offered to guide future research.     

Representation and constraints: the inverse problem and the structure of visual space

Visual space can be distinguished from physical space. The first is found in visual experience, while the second is defined independently of perception. Theorists have wondered about the relation between the two. Some investigators have concluded that visual space is non-Euclidean, and that it does not have a single metric structure. Here it is argued (1) that visual space exhibits contraction in all three dimensions with increasing distance from the observer, (2) that experienced features of this contraction (including the apparent convergence of lines in visual experience that are produced from physically parallel stimuli in ordinary viewing conditions) are not the same as would be the experience of a perspective projection onto a frontoparallel plane, and (3) that such contraction is consistent with size constancy. These properties of visual space are different from those that would be predicted if spatial perception resulted from the successful solution of the inverse problem. They are consistent with the notion that optical constraints have been internalized. More generally, they are also consistent with the notion that visual spatial structures bear a resemblance relation to physical spatial structures. This notion supports a type of representational relation that is distinct from mere causal correspondence. The reticence of some philosophers and psychologists to discuss the structure of phenomenal space is diagnosed in terms of the simple materialism and the functionalism of the 1970s and 1980s.     

Accuracy and precision of binocular 3-D motion perception

In principle, information for 3-D motion perception is provided by the differences in position and motion between left- and right-eye images of the world. It is known that observers can precisely judge between different 3-D motion trajectories, but the accuracy of binocular 3-D motion perception has not been studied. The authors measured the accuracy of 3-D motion perception. In 4 different tasks, observers were inaccurate, overestimating trajectory angle, despite consistently choosing similar angles (high precision). Errors did not vary consistently with target distance, as would be expected had inaccuracy been due to misestimates of viewing distance. Observers appeared to rely strongly on the lateral position of the target, almost to the exclusion of the use of depth information. For the present tasks, these data suggest that neither an accurate estimate of 3-D motion direction nor one of passing distance can be obtained using only binocular cues to motion in depth. ((c) 2003 APA, all rights reserved)     

Opposed left and right brain hemisphere contributions to sexual drive: a multiple lesion case analysis

Brain topographical studies of normal men have have shown that sexual excitation is asymmetric in the brain hemispheres. Group studies of patients with unilateral epileptic foci and other studies of patients with unilateral brain lesions have come to the same conclusion. The present study reviewed previously published single case reports of patients with frank hypo or hypersexuality subsequent to a unilateral brain lesion. Hyposexual patients tended to have left hemisphere lesions (primarily of the temporal lobe), and hypersexual patients tended to have right hemisphere lesions (primarily of the temporal lobe) (p < 0.05). We interpret this double dissociation as part of a more general phenomenon of psychic tone similarly dissociated with regard to hemispheric control, including mood, psychomotor baseline, speech rate, and even immunity. The behavioral significance of this psychic tone is to modulate approach versus avoidance behavior.     

Bouts of responding from variable-interval reinforcement of lever pressing by rats

Four rats obtained food pellets by lever pressing. A variable-interval reinforcement schedule assigned reinforcers on average every 2 min during one block of 20 sessions and on average every 8 min during another block. Also, at each variable-interval duration, a block of sessions was conducted with a schedule that imposed a variable-ratio 4 response requirement after each variable interval (i.e., a tandem variable-time variable-ratio 4 schedule). The total rate of lever pressing increased as a function of the rate of reinforcement and as a result of imposing the variable-ratio requirement. Analysis of log survivor plots of interresponse times indicated that lever pressing occurred in bouts that were separated by pauses. Increasing the rate of reinforcement increased total response rate by increasing the rate of initiating bouts and, less reliably, by lengthening bouts. Imposing the variable-ratio component increased response rate mainly by lengthening bouts. This pattern of results is similar to that reported previously with key poking as the response. Also, response rates within bouts were relatively insensitive to either variable.