Interactions between orientation and contrast modulations suggest limited cross-cue linkage

Recent studies of texture segmentation and second-order vision have proposed very similar models for the detection of orientation modulation and contrast modulation (OM and CM). From the similarity of the models it is tempting to assume that the two cues might be processed by a single generalised texture mechanism; however, recent results (Kingdom et al, 2003 Visual Neuroscience 2 65-76) have suggested that these cues are detected independently, or at least in a mechanism that is able to maintain an apparent independence between the cues. We tested new combinations of OM and CM and found that CM at 0.4 cycle deg(-1) facilitates the detection of OM at 0.2 cycle deg(-1) when the peaks of contrast align with the extremes of orientation. There is also some evidence of weak facilitation of CM by OM under the same conditions. Further, this facilitation can be predicted by filter--rectify--filter channels optimised for the detection of each cue, adding weight to the argument that texture cues are processed in a single generalised mechanism that nonetheless achieves cue independence or near-independence in many circumstances. We also found that the amount of suprathreshold masking produced by an orientation cue depends on the overall percept formed by that cue.     

Preferences Regarding Targeted Education and Risk Assessment in People with a Family History of Major Depressive Disorder

Genetic testing for susceptibility to major depressive disorder (MDD) is not available for clinical use at present. Given this, family history remains the best predictor for development of MDD, and family-history-based risk assessment and information about familial aspects of MDD may be useful to clients at increased risk for MDD attending for genetic counseling. This study uses a mixed-methods design to assess the information needs and preferences of people at increased familial risk for MDD. Telephone interviews were conducted with 23 individuals, who had at least one first-degree relative with MDD and were recruited through advertisements placed on depression education websites. The most preferred way to access depression information was via the internet (87 % of participants), although this preference may have been due to the internet-based recruitment method. The second most preferred dissemination strategy (56 %) was face-to-face delivery through a health professional, including genetic counselors. Individuals reported a need for information about etiology and development of MDD, reproductive decision-making, early detection of symptoms and risk-reducing strategies. Nearly all participants expressed an interest in risk assessment. The present study found evidence of a high level of interest for information targeted to people at increased familial risk for MDD. Genetic counselors are likely to be called upon increasingly to provide supportive counseling to assist clients at increased familial risk in interpreting and contextualizing such information once it becomes available.