Increased responding to female stimuli as a result of sexual experience: Tests of mechanisms of learning

Sexual experience increases the response of males to stimuli provided by female conspecifics in a variety of species. The mechanisms of learning involved in this type of phenomenon were explored in two experiments with Japanese quail. The results indicated that instrumental conditioning with copulatory opportunity is not necessary for the acquisition of responding to female cues, and responding is not facilitated by learning about the location of the female. However, the response of males to female stimuli (as well as to arbitrary stimuli associated with access to a female) was enhanced by the presence of sexually conditioned contextual cues. Substantial levels of responding also occurred to female stimuli in a context where the subjects never encountered a female quail before. This latter outcome is consistent with the possibility that stimuli from a female become directly associated with sexual reinforcement during the course of sexual experience. Similar forms of learning may be involved in the effects of sexual experience on the response of mammalian species to female odours.     

PSYCHOMETRIC CHARACTERISTICS OF THE SOCIAL REACTIONS QUESTIONNAIRE

Negative social reactions are common responses to disclosures of sexual assault. A study was undertaken to evaluate the psychometric characteristics of a new measure of social reactions to sexual assault victims, the Social Reactions Questionnaire (SRQ). Good reliability and validity were demonstrated for the measure in three samples of sexual assault victims: community volunteers, college students, and victims contacting mental health agencies. The SRQ provides a much needed measure of both the positive forms of social support and several negative social reactions received by sexual assault victims disclosing their assaults to a range of informal social network members and formal support providers.     

Curve tracing: A possible basic operation in the perception of spatial relations

The two experiments in this study suggest that fast internal tracing of curves is employed by the visual system in the perception of certain shape properties and spatial relations. The experimental task in the first experiment was to determine, as rapidly as possible, whether two Xs lay on the same curve or on different curves in a visual display. Mean response time for “same” responses increased monotonically with increasing distance along the curve between the Xs. The task in the second experiment was to decide either that a curve joining two Xs was unbroken or that the curve had a gap. Decision times again increased as the length of the curve joining the Xs was increased. The results of both experiments suggest that people can trace curves in a visual display internally at high speed (the average rate of tracing was about 40° of visual angle per second). Curve tracing may be an important visual process used to integrate information from different parts of a visual display.     

Contingencies of Exogenous Reward and Task Performance: On the “Minimax” Strategy in instrumental Behavior1

Subjects performed a task in return for monetary payment. In one experimental condition, the subject's pay was contingent on his working at the task for at least the time specified, in another condition, the pay was contingent on the subject's completion of at least the specified output standard; in a third condition, the amount of pay was contingent on the quantity of output. It was found that subjects in the time-contingent condition adhered most closely to the task's time specification, subjects in the standard-contingent condition adhered most closely to the standard specification, and subjects in the output-contingent condition produced the highest quantities of output. The results are discussed in reference to the idea that extrinsically motivated workers act in accordance with a “minimax” strategy: They attempt to perform the bare minimum of work sufficient for the achievement of maximal rewards.     

Children's lateral preference patterns: Frequency and relationships with achievement and intelligence

The frequencies of consistent, mixed, and inconsistent lateral preference patterns in 648 elementary school age children were examined. Preference was determined by 18 different hand, eye, and foot tasks. Almost 60% of the younger children and 35% of the older children demonstrated either mixed or inconsistent patterns. No differences were found in IQ, reading, arithmetic, or spelling achievement scores among the three groups of children, at any age or for either sex. Both the absence of any differences among the groups and the high frequency of mixed and inconsistent patterns in a normal population call into question the clinical utility of such patterns as either indices or correlates of learning difficulties.     

Visual curve tracing properties

Subjects decided whether 2 dots were on the same curve or 2 different curves, and the curvature of the curves or the proximity of other (distractor) curves to the target curve was varied. Response time increased as the arc length of the curve connecting the 2 dots increased, suggesting that the curve was traced to perform the task. Tracing rate was faster for low- than high-curvature contours and was increasingly slower as distractor contours were increasingly proximal to the traced curve. Proximity results were predicted by a model in which response time depends on the ratio of the distance between the dots and the distance between adjacent lines. Curve tracing operations used to integrate information along contours are sensitive to several properties of the contours. The implications of the sensitivity of tracing operations to these curve properties are discussed.     

Sexual Assault History and Health-Related Outcomes in a National Sample of Women

This study examined correlates of past-year chronic medical conditions and lifetime contact with health care professionals for mental health and substance abuse problems in women with differing histories of sexual victimization  ( N  = 627)  identified from the National Comorbidity Survey (e.g., assault in childhood, adulthood, or both life phases). Posttraumatic stress disorder (PTSD) and stressful life events were associated with greater odds of chronic medical conditions among women sexually assaulted in childhood only. Additional traumatic events were associated with greater odds of chronic medical conditions among victims of adult sexual assault. Older age and being married were associated with greater odds of lifetime health care professional contact for mental health/substance abuse issues among certain victim subgroups. Stressful life events were related to greater help-seeking for child victims, and traumatic events were related to greater help-seeking in adult victims. Alcohol dependence symptoms and PTSD were each associated with greater odds of lifetime health care professional contact among women victimized in both life phases, whereas depression was related to greater odds of help-seeking for women victimized in one life phase only. Psychosocial factors may play unique roles in health outcomes for women with different sexual assault histories.     

Object recognition and segmentation by a fragment-based hierarchy

How do we learn to recognize visual categories, such as dogs and cats? Somehow, the brain uses limited variable examples to extract the essential characteristics of new visual categories. Here, I describe an approach to category learning and recognition that is based on recent computational advances. In this approach, objects are represented by a hierarchy of fragments that are extracted during learning from observed examples. The fragments are class-specific features and are selected to deliver a high amount of information for categorization. The same fragments hierarchy is then used for general categorization, individual object recognition and object-parts identification. Recognition is also combined with object segmentation, using stored fragments, to provide a top-down process that delineates object boundaries in complex cluttered scenes. The approach is computationally effective and provides a possible framework for categorization, recognition and segmentation in human vision.