Assessment of combat-related stress and physical symptoms of Gulf War veterans: criterion validity of selected hand test variables

We examined the utility of selected Hand Test (Wagner, 1983) variables in relation to posttraumatic stress and physical symptoms in Gulf War (GW) veterans. In this study, we sought to replicate and expand on prior empirical findings that have demonstrated efficacy of the Hand Test in the assessment of posttraumatic stress disorder (PTSD; Walter, Hilsenroth, Arsenault, Sloan, & Harvill, 1998). Based on this previous research, Hand Test variables were selected a priori and examined across three groups of veterans: (a) a control group of participants who were in a reserve unit not deployed to the GW theater of operations, (b) a subclinical group of deployed GW veterans who reported 1 to 5 Diagnostic and Statistical Manual of Mental Disorders (4th ed. [DSM-IV]; American Psychiatric Association, 1994) criteria for PTSD, and (c) a group of deployed GW veterans who met DSM-IV criteria for PTSD. Analyses demonstrated significant differences across the three groups and significant relationships among selected Hand Test variables with the number of DSM-IV symptoms of PTSD reported in the interviews as well as with the number of physical problems reported by these veterans. We discuss these findings in relation to the assessment and treatment of posttraumatic stress symptomatology.     

Perceiving illumination inconsistencies in scenes

The human visual system is adept at detecting and encoding statistical regularities in its spatiotemporal environment. Here, we report an unexpected failure of this ability in the context of perceiving inconsistencies in illumination distributions across a scene. Prior work with arrays of objects all having uniform reflectance has shown that one inconsistently illuminated target can 'pop out' among a field of consistently illuminated objects (eg Enns and Rensink, 1990 Science 247 721 723; Sun and Perona, 1997 Perception 26 519-529). In these studies, the luminance pattern of the odd target could be interpreted as arising from either an inconsistent illumination or inconsistent pigmentation of the target. Either cue might explain the rapid detection. In contrast, we find that once the geometrical regularity of the previous displays is removed, the visual system is remarkably insensitive to illumination inconsistencies, both in experimental stimuli and in altered images of real scenes. Whether the target is interpreted as oddly illuminated or oddly pigmented, it is very difficult to find if the only cue is deviation from the regularity of illumination or reflectance. Our results allow us to draw inferences about how the visual system encodes illumination distributions across scenes. Specifically, they suggest that the visual system does not verify the global consistency of locally derived estimates of illumination direction.     

Self-determination and conflict in romantic relationships

Four studies examined associations between E. L. Deci and R. M. Ryan's (1985, 2000) construct of autonomy, responses to relationship disagreements, and dissatisfaction after conflict. In Study 1, diary data showed that trait autonomy predicted relationship autonomy, which in turn predicted relative satisfaction after disagreements. In Study 2, trait autonomy predicted relationship autonomy, which was associated with less defensive and more understanding responses to conflict. Studies 3 and 4 examined whether one's partner's relationship autonomy uniquely predicted reported and observed behavior during conflict. Autonomous reasons for being in the relationship (of both self and partner) predicted both reported and observed responses to conflict and feelings of satisfaction.     

The role of local and global properties in comparison of analogical visual scenes

Love, Rouder, and Wisniewski (1999) obtained interesting results showing that, in a same/different task on abstract visual scenes, subjects were able to process global properties quickly, even before local properties were identified. Our aim in this work is to explore more fully the complex relationships that exist between local processing and global processing. In our first experiment, we tested the robustness and generality of these global and local effects by using another, very different kind of local element. We showed that the global effects remain strong even when the local elements are neither conventional nor easily discriminable. In the second experiment, we showed that there exists an intermediate level of similarity between purely local and purely global similarity. Furthermore, we found that even when a stronger form of local dissimilarity is manipulated (through the introduction of different local elements), global effects were still observed. We conclude with a discussion of the respective roles of global and local properties in light of our findings.     

Psycholinguistic norms for action photographs in French and their relationships with spoken and written latencies

A set of 142 photographs of actions (taken from Fiez & Tranel, 1997) was standardized in French on name agreement, image agreement, conceptual familiarity, visual complexity, imageability, age of acquisition, and duration of the depicted actions. Objective word frequency measures were provided for the infinitive modal forms of the verbs and for the cumulative frequency of the verbal forms associated with the photographs. Statistics on the variables collected for action items were provided and compared with the statistics on the same variables collected for object items. The relationships between these variables were analyzed, and certain comparisons between the current database and other similar published databases of pictures of actions are reported. Spoken and written naming latencies were also collected for the photographs of actions, and multiple regression analyses revealed that name agreement, image agreement, and age of acquisition are the major determinants of action naming speed. Finally, certain analyses were performed to compare object and action naming times. The norms and the spoken and written naming latencies corresponding to the pictures are available on the Internet (http://www.psy.univ-bpclermont.fr/~pbonin/pbonin-eng.html) and should be of great use to researchers interested in the processing of actions.     

Facilitated processing of visual stimuli associated with the body

Recent work on tactile perception has revealed enhanced tactile acuity and speeded spatial-choice reaction times (RTs) when viewing the stimulated body site as opposed to viewing a neutral object. Here we examine whether this body-view enhancement effect extends to visual targets. Participants performed a speeded spatial discrimination between two lights attached either to their own left index finger or to a wooden finger-shaped object, making a simple distal--proximal decision. We filmed either the finger-mounted or the object-mounted lights in separate experimental blocks and the live scene was projected onto a screen in front of the participants. Thus, participants responded to identical visual targets varying only in their context: on the body or not. Results revealed a large performance advantage for the finger-mounted stimuli: reaction times were substantially reduced, while discrimination accuracy was unaffected. With this finding we address concerns associated with previous work on the processing of stimuli attributed to the self and extend the finding of a performance advantage for such stimuli to vision.     

Testing main effects and interactions in latent curve analysis

A key strength of latent curve analysis (LCA) is the ability to model individual variability in rates of change as a function of 1 or more explanatory variables. The measurement of time plays a critical role because the explanatory variables multiplicatively interact with time in the prediction of the repeated measures. However, this interaction is not typically capitalized on in LCA because the measure of time is rather subtly incorporated via the factor loading matrix. The authors' goal is to demonstrate both analytically and empirically that classic techniques for probing interactions in multiple regression can be generalized to LCA. A worked example is presented, and the use of these techniques is recommended whenever estimating conditional LCAs in practice.     

Neuroepileptic correlates of autistic symptomatology in tuberous sclerosis

Tuberous sclerosis is a genetic condition that is strongly associated with the development of an autism spectrum disorder. However, there is marked variability in expression, and only a subset of children with tuberous sclerosis develop autism spectrum disorder. Clarification of the mechanisms that underlie the association and variability in expression will potentially throw light on the biological processes involved in the etiology of idiopathic forms of autism spectrum disorder. Current evidence indicates that the likelihood of a child with tuberous sclerosis developing an autism spectrum disorder is greater if the child has a mutation in the TSC2 gene, although autism can and does develop in children with TSC1 mutations. The likelihood is also greater if the child has early-onset infantile spasms that are difficult to control, especially if there is an epileptiform focus in the temporal lobes. The emerging evidence is consistent with the notion that early onset electrophysiological disturbances within the temporal lobes (and perhaps other locations) has a deleterious effect on the development and establishment of key social cognitive representations concerned with processing social information, perhaps especially from faces. However, alternative mechanisms to account for the findings cannot yet be ruled out. Future research will have to employ prospective longitudinal designs and treatment trials to clarify the processes involved.     

Psychometric properties of the life events checklist

The Life Events Checklist (LEC), a measure of exposure to potentially traumatic events, was developed at the National Center for Posttraumatic Stress Disorder (PTSD) concurrently with the Clinician Administered PTSD Scale (CAPS) to facilitate the diagnosis of PTSD. Although the CAPS is recognized as the gold standard in PTSD symptom assessment, the psychometric soundness of the LEC has never been formally evaluated. The studies reported here describe the performance of the LEC in two samples: college undergraduates and combat veterans. The LEC exhibited adequate temporal stability, good convergence with an established measure of trauma history -- the Traumatic Life Events Questionnaire (TLEQ) -- and was comparable to the TLEQ in associations with variables known to be correlated with traumatic exposure in a sample of undergraduates. In a clinical sample of combat veterans, the LEC was significantly correlated, in the predicted directions, with measures of psychological distress and was strongly associated with PTSD symptoms.