Abductive reasoning in neural-symbolic systems

Abduction is or subsumes a process of inference. It entertains possible hypotheses and it chooses hypotheses for further scrutiny. There is a large literature on various aspects of non-symbolic, subconscious abduction. There is also a very active research community working on the symbolic (logical) characterisation of abduction, which typically treats it as a form of hypothetico-deductive reasoning. In this paper we start to bridge the gap between the symbolic and sub-symbolic approaches to abduction. We are interested in benefiting from developments made by each community. In particular, we are interested in the ability of non-symbolic systems (neural networks) to learn from experience using efficient algorithms and to perform massively parallel computations of alternative abductive explanations. At the same time, we would like to benefit from the rigour and semantic clarity of symbolic logic. We present two approaches to dealing with abduction in neural networks. One of them uses Connectionist Modal Logic and a translation of Horn clauses into modal clauses to come up with a neural network ensemble that computes abductive explanations in a top-down fashion. The other combines neural-symbolic systems and abductive logic programming and proposes a neural architecture which performs a more systematic, bottom-up computation of alternative abductive explanations. Both approaches employ standard neural network architectures which are already known to be highly effective in practical learning applications. Differently from previous work in the area, our aim is to promote the integration of reasoning and learning in a way that the neural network provides the machinery for cognitive computation, inductive learning and hypothetical reasoning, while logic provides the rigour and explanation capability to the systems, facilitating the interaction with the outside world. Although it is left as future work to determine whether the structure of one of the proposed approaches is more amenable to learning than the other, we hope to have contributed to the development of the area by approaching it from the perspective of symbolic and sub-symbolic integration.

Suicidal ideation versus suicidal obsession: a case report

This case report illustrates the relationship between stress and obsessive-compulsive disorder (OCD) by describing an unusual case of OCD sequelae following a suicide attempt. The patient is a 29-year-old married woman who suffered a major depressive episode without OCD and tried to commit suicide by drinking household cleaner. Following the attempt, violent obsessive thoughts of harming herself and others emerged along with avoidance behavior. After exposure therapy, there was a decrease in her obsessive thoughts, less anxiety, and no avoidance behavior. This report highlights not only the existence of "posttraumatic obsession" but also the importance of accurate interpretation of suicidal preoccupation, leading to the diagnosis of OCD rather then suicidal ideation secondary to depression.     

Obsessive-compulsive disorder: boundary issues

The boundaries between obsessive-compulsive disorder (OCD) and other neuropsychiatric disorders remain unresolved and may well differ from one disorder to another. Endophenotypes are heritable, quantitative traits hypothesized to more closely represent genetic risk for complex polygenic mental disorders than overt symptoms and behaviors. They may have a role in identifying how closely these disorders are associated with another and with other mental disorders with which they share major comorbidity. This review maps the nosological relationships of OCD to other neuropsychiatric disorders, using OCD as the prototype disorder and endophenotype markers, such as cognitive, imaging, and molecular data as well as results from demographic, comorbidity, family, and treatment studies. Despite high comorbidity rates, emerging evidence suggests substantial endophenotypic differences between OCD and anxiety disorders, depression, schizophrenia, and addictions, though comparative data is lacking and the picture is far from clear. On the other hand, strong relationships between OCD, Tourette syndrome, body dysmorphic disorder, hypochondriasis, grooming disorders, obsessive-compulsive personality disorder, and pediatric autoimmune neuropsychiatric disorders associated with streptococcus are likely. Studies designed to delineate the cause, consequences, and common factors are a challenging but essential goal for future research in this area.     

The psychometric properties of the Hebrew version of Cloninger's Tridimensional Personality Questionnaire

The Hebrew Tridimensional Personality Questionnaire was administered to over a thousand individuals in the community, 16–78 years of age. Factor analysis was run first on individual items, and then on the 12 sub-scales described by [Cloninger, C.R., Pryzbeck, T.R., & Svrakic, D.M. (1991). The TPQ: US normative data. Psychological Reports, 69, 1047–1051)]. The factor analyses were restricted to four orthogonal factors in order to attempt confirmation of the corrected four-factor solution [Stallings, M.C., Hewitt, J.K., Cloninger, R.C., Heath, A.C., & Eaves, L.J. (1996). Genetic and environmental structure of the TPQ: three or four temperament dimensions? Journal of Personality and Social Psychology, 70 (1), 127–140)]. In the individual item analysis four orthogonal factors recognizable as Novelty Seeking, Reward Dependence, Harm Avoidance and Persistence emerged. However only up to half of the items originally ascribed to each factor loaded sufficiently and exclusively on the appropriate factor. When the 12 sub-scales were entered into factor analysis the four orthogonal factors were produced, and the structure satisfactorily confirmed. A few exceptions to orthogonality were observed. The data were analyzed for sex differences and age effects. Women scored higher than men did on most sub-scales of Harm Avoidance and Reward Dependence. The younger group (up to 21 years of age) scored higher on Novelty Seeking and Reward Dependence and lower on Harm Avoidance than the older group, but no sex by age interaction was detected. Preliminary normative Israeli data are supplied, and implications of the group differences discussed.     

Effects of energy availability on immediate and delayed emotional reactions to work events

This study focuses on daily work events as proximal stimuli for discrete emotional reactions and suggests that availability of energy resources required for coping with goal-disruptive events, or for capitalizing on new opportunities offered by goal-enhancing events, influences intensity of emotional reactions. Using experience-sampling methodology with a sample of hospital residents, it is shown that negative emotion and fatigue following disruptive events are intensified when only limited energy resources are available due to current workload. However, positive emotions, promoted by goal-enhancing events, are mitigated due to inability to capitalize on new opportunities or challenges. Aftereffects of work events reveal that the energizing effect of goal-enhancing events mitigates end-of-day fatigue and negative emotion on high-workload days, although the effect of disruptive events is diminished by the end of such days, apparently because of lesser conspicuity against a background of high workload. Theoretical and practical implications are discussed.     

Optimizing well-being: the empirical encounter of two traditions

Subjective well-being (SWB) is evaluation of life in terms of satisfaction and balance between positive and negative affect; psychological well-being (PWB) entails perception of engagement with existential challenges of life. The authors hypothesized that these research streams are conceptually related but empirically distinct and that combinations of them relate differentially to sociodemographics and personality. Data are from a national sample of 3,032 Americans aged 25-74. Factor analyses confirmed the related-but-distinct status of SWB and PWB. The probability of optimal well-being (high SWB and PWB) increased as age, education, extraversion, and conscientiousness increased and as neuroticism decreased. Compared with adults with higher SWB than PWB. adults with higher PWB than SWB were younger, had more education, and showed more openness to experience.     

As seen by the other...: Perspectives on the self in the memories and emotional perceptions of Easterners and Westerners

The experiment reported investigated the phenomenological consequences of Easterners' and Westerners' perspectives on the self. Two findings are consistent with the notion that Asians are more likely than Westerners to experience the self from the perspective of the generalized other. First, Eastern participants were more likely than Western participants to have third-person (as opposed to first-person) memories when they thought about situations in which they would be at the center of a scene. Second, Easterners and Westerners engaged in different sorts of projections when they read the emotional expressions of other people. Westerners were more biased than Easterners toward egocentric projection of their own emotions onto others, whereas Easterners were more biased than Westerners toward relational projection, in which they projected onto others the emotions that the generalized other would feel in relation to the participant. Implications for how phenomenological experiences could reinforce different Eastern and Western ideologies about the self and the group are discussed.