False feedback increases detection of low-prevalence targets in visual search

Many critical search tasks, such as airport and medical screening, involve searching for targets that are rarely present. These low-prevalence targets are associated with extremely high miss rates Wolfe, Horowitz, & Kenner (Nature, 435, 439?C440, 2005). The inflated miss rates are caused by a criterion shift, likely due to observers attempting to equate the numbers of misses and false alarms. This equalizing strategy results in a neutral criterion at 50?% target prevalence, but leads to a higher proportion of misses for low-prevalence targets. In the present study, we manipulated participants?? perceived number of misses through explicit false feedback. As predicted, the participants in the false-feedback condition committed a higher number of false alarms due to a shifted criterion. Importantly, the participants in this condition were also more successful in detecting targets. These results highlight the importance of perceived prevalence in target search tasks.     

Civilian Immunity,Supreme Emergency,and Moral Disaster

Any plausible position in the ethics of war and political violence in general will include the requirement of protection of civilians (non-combatants, common citizens) against lethal violence. This requirement is particularly prominent, and particularly strong, in just war theory. Some adherents of the theory see civilian immunity as absolute, not to be overridden in any circumstances whatsoever. Others allow that it may be overridden, but only in extremis. The latter position has been advanced by Michael Walzer under the heading of “supreme emergency.” In this paper, I look into some of the issues of interpretation and application of Walzer’s “supreme emergency” view and some of the criticisms that have been levelled against it. I argue that Walzer’s view is vague and unacceptable as it stands, but that the alternatives proposed by critics such as Brian Orend, C.A.J. Coady, and Stephen Nathanson are also unattractive. I go on to construct a position that is structurally similar to Walzer’s, but more specific and much less permissive, which I term the “moral disaster” view. According to this view, deliberate killing of civilians is almost absolutely wrong.     

A depictive neural model for the representation of motion verbs

In this paper, we present a depictive neural model for the representation of motion verb semantics in neural models of visual awareness. The problem of modelling motion verb representation is shown to be one of function application, mapping a set of given input variables defining the moving object and the path of motion to a defined output outcome in the motion recognition context. The particular function-applicative implementation and consequent recognition model design presented are seen as arising from a noun-adjective recognition model enabling the recognition of colour adjectives as applied to a set of shapes representing objects to be recognised. The presence of such a function application scheme and a separately implemented position identification and path labelling scheme are accordingly shown to be the primitives required to enable the design and construction of a composite depictive motion verb recognition scheme. Extensions to the presented design to enable the representation of transitive verbs are also discussed.     

Integration of the pleasant events and activity restriction models: development and validation of a "PEAR" model of negative outcomes in Alzheimer's caregivers

This study examined an activity restriction/pleasurable activities mismatch model for psychosocial and health-related outcomes. A total of 108 spousal caregivers of patients with Alzheimer's Disease (AD) were assessed for their experience of social and recreational activities over the past month as well as their perception of how restricted they were for engaging in social and recreational activities. Participants were divided into three groups based on their reported activities and activity restriction: HPLR = High Pleasant Events + Low Activity Restriction (i.e., reference group; N = 28); HPHR/LPLR = Either High Pleasant Events + High Activity Restriction or Low Pleasant Events + Low Activity Restriction (N = 43); LPHR = Low Pleasant Events + High Activity Restriction (N = 37). We hypothesized that participants reporting low pleasant events combined with high activity restriction (LPHR) would demonstrate greater disturbance relative to other two groups in multiple outcome domains, including: (a) greater mood disturbance, (b) greater use of negative coping factors, (c) reduced use of positive coping strategies, (d) reduced report of psychological resource factors (e.g., personal mastery, self-efficacy), and (e) increased report of subjective health difficulties (e.g., sleep disturbance). Results generally supported our hypotheses, suggesting that assessment of both constructs is important for best predicting quality of well-being in AD caregivers, and potentially for establishing maximal effect in behavior therapy for caregivers.     

Kaufmann on the Probabilities of Conditionals

Kaufmann has recently argued that the thesis according to which the probability of an indicative conditional equals the conditional probability of the consequent given the antecedent under certain specifiable circumstances deviates from intuition. He presents a method for calculating the probability of a conditional that does seem to give the intuitively correct result under those circumstances. However, the present paper shows that Kaufmann’s method is inconsistent in that it may lead one to assign different probabilities to a single conditional at the same time.     

Parallel averaging of size is possible but range-limited: A reply to Marchant,Simons, and De Fockert

In their recent paper, Marchant, Simons, and De Fockert (2013) claimed that the ability to average between multiple items of different sizes is limited by small samples of arbitrarily attended members of a set. This claim is based on a finding that observers are good at representing the average when an ensemble includes only two sizes distributed among all items (regular sets), but their performance gets worse when the number of sizes increases with the number of items (irregular sets). We argue that an important factor not considered by Marchant et al. (2013) is the range of size variation that was much bigger in their irregular sets. We manipulated this factor across our experiments and found almost the same efficiency of averaging for both regular and irregular sets when the range was stabilized. Moreover, highly regular sets consisting only of small and large items (two-peaks distributions) were averaged with greater error than sets with small, large, and intermediate items, suggesting a segmentation threshold determining whether all variable items are perceived as a single ensemble or distinct subsets. Our results demonstrate that averaging can actually be parallel but the visual system has some difficulties with it when some items differ too much from others.     

Long-term memory for traumatic events: experiences and emotional reactions during the 2000 flood in Italy

The authors investigated how people remember real-life traumatic events. Adult residents (N = 145) of an Italian community that was flooded in fall of 2000 completed a questionnaire 3 years after the flood. Respondents briefly recounted their personal experiences with the flood and answered questions about emotional reactions to the flood, appraisal processes, and disaster exposure. Results showed that participants tended to recall experiences that occurred during the most critical phases of the disaster. The emotions most strongly experienced by respondents-sadness, fear, and surprise-were associated with specific appraisals. Content and amount of memories about flood experiences did not significantly vary as a function of flood exposure. Moreover, there was no significant relationship between memory quantity and emotional intensity. The authors discuss findings in the context of literature on traumatic memory and emotion.     

Specificity of cognitive and behavioral variables to Positive and Negative Affect

The Tripartite Model proposes that a combination of greater Negative Affect (NA) and reduced Positive Affect (PA) contributes to depressive symptoms. The purpose of this study was to test a model of affective experience in which cognitive variables (i.e., negative cognitions and appraisals) are uniquely related to NA but not PA, and in which behavioral variables (i.e., activity participation) are uniquely associated with PA but not NA. Participants included 88 spousal Alzheimer caregivers (mean age = 74 years). Multiple regression models, in which negative cognitions (i.e., helplessness, blames self, and negative appraisals) and activity participation (i.e., frequency of engaging in social and recreational activities) were used to predict depressive symptoms, PA and NA. Results indicated that while helplessness, blaming oneself, negative appraisals, and activity participation all significantly predicted depressive symptoms, only negative cognitive variables significantly predicted NA, and only activity participation significantly predicted PA. These data confirm that depressive experience consists of two relatively independent components - increased Negative Affect and reduced Positive Affect - which have unique correlates in negative cognitions and activity participation. If confirmed, the findings suggest the utility of focusing interventions on each of these components in the management of depressive symptoms.