Interocular suppression differentially affects achromatic and chromatic mechanisms

Results from a series of psychophysical experiments show that interocular suppression produced by continuous flash suppression (CFS) differentially affects visual features of a target viewed by the other eye. When CFS stimuli are defined by luminance contrast, target color can be reliably identified but percent-correct discrimination of target orientation is near chance. When the colored target is moving, color identification deteriorates with motion speed but direction of motion discrimination improves with target speed. Color’s immunity to suppression is also weakened when interocular suppression is induced by equiluminant CFS stimuli that presumably stimulate the chromatic pathway. These results are discussed in terms of functional segregation of achromatic and chromatic processing in the visual system.     

The embodied nature of spatial perspective taking: Embodied transformation versus sensorimotor interference

Humans are able to mentally adopt the spatial perspective of others and understand the world from their point of view. We propose that spatial perspective taking (SPT) could have developed from the physical alignment of perspectives. This would support the notion that others have put forward claiming that SPT is an embodied cognitive process. We investigated this issue by contrasting several accounts in terms of the assumed processes and the nature of the embodiment. In a series of four experiments we found substantial evidence that the transformations during SPT comprise large parts of the body schema, which we did not observe for object rotation. We further conclude that the embodiment of SPT is best conceptualised as the self-initiated emulation of a body movement, supporting the notion of endogenous motoric embodiment. Overall our results are much more in agreement with an ‘embodied’ transformation account than with the notion of sensorimotor interference. Finally we discuss our findings in terms of SPT as a possible evolutionary stepping stone towards more complex alignments of socio-cognitive perspectives.     

Methodological considerations in developing measures of HIV risk-relevant behaviors and attitudes: An empirical illustration

Abstract

This paper describes the pilot testing of a survey designed to assess the prevalence of HIV exposure risk-relevant behaviors and associated attitudes, beliefs and knowledge in a heterogeneous, ethnically diverse, sexually active population (the US Army). The specific objectives for the pilot test were to: (1) define optimal survey question formats for behavioral and attitude items; (2) identify questions that were poorly worded or that would not contribute to the overall objectives of the survey; (3) assess the extent to which respondents could accurately follow instructions; (4) identify appropriate and culturally relevant terminology for sensitive items; (5) determine the appropriate timeframe for recall of simple and complex sexual behaviors; (6) assess the degree of respondent honesty and belief in the anonymity of the survey results.     

Developments in child psychotherapy in Australia: an introduction

This article describes a type of intervention with parents that attempts to stimulate and encourage empathic imagination in relation to their child's difficult behaviour. Some barriers to this process are explored in the context of wider cultural influences, particularly as they pertain to the USA. Basic cultural assumptions about children, their emotional life and development, are contrasted to basic assumptions in British Object Relations Theory. Examples of parent consultations are offered and theoretical reference points are suggested.     

Families created through surrogacy: mother-child relationships and children's psychological adjustment at age 7

Each year, an increasing number of children are born through surrogacy and thus lack a genetic and/or gestational link with their mother. This study examined the impact of surrogacy on mother-child relationships and children's psychological adjustment. Assessments of maternal positivity, maternal negativity, mother-child interaction, and child adjustment were administered to 32 surrogacy, 32 egg donation, and 54 natural conception families with a 7-year-old child. No differences were found for maternal negativity, maternal positivity, or child adjustment, although the surrogacy and egg donation families showed less positive mother-child interaction than the natural conception families. The findings suggest that both surrogacy and egg donation families function well in the early school years.     

Socialization Tactics and Newcomer Information Acquisition

Research on organizational socialization has usually focused on what organizations do to socialize newcomers or on what newcomers do to socialize themselves. The purpose of this study was to integrate these two perspectives of socialization by investigating the relationships between socialization tactics, newcomers' information acquisition (i.e. feedback and observation) and socialization outcomes. Consistent with previous research, socialization tactics and information acquisition were related to socialization outcomes. Furthermore, institutionalized socialization was positively related to the frequency of newcomers' feedback and observation and the frequency of newcomers' feedback and observation was found to mediate several of the relationships between socialization tactics and outcomes. These results suggest that what newcomers can do to socialize themselves (e.g. acquire information through feedback and observation) is partly a function of what organizations do to socialize newcomers (e.g. the use of specific socialization tactics). The implications of these findings are discussed for the development of a more complete and integrated theory of organizational socialization.     

An intrahemispheric integration deficit in dyslexia

In order to investigate the hypothesis that dyslexia may result from a failure of intrahemispheric integration between auditory-verbal and visual-verbal processing, a dichotic listening task and a parallel divided visual field task were administered to a group of dyslexic boys between the ages of 8 and 11 years, and a group of normal control subjects individually matched for age and WISC intelligence. The dyslexics were on average over two years retarded in reading and spelling. Dyslexics exhibited a normal right ear advantage on dichotic listening for digits although lesser right ear advantage was related to reading retardation. In the divided visual field task, the normal controls showed a left visual field advantage for digits which it is argued resulted from a failure in fixation linked to reading habits. Within the dyslexic group greater reading deficiency was associated with relative bilateralization for visual verbal processing. The results therefore support the hypothesis.     

Perception of two-component electrocutaneous stimuli

Electrocutaneous stimuli varying in strength (6, 8, 10 V) and frequency (9, 27, 81 Hzj were presented in pairs. Subjects were asked to give a numerical score to represent their perception of overall difference in a pair. To assess their ability to use numbers and their performance on unfamiliar stimuli, no guidance on the nature of the stimuli or the range or scale of the scores was given. Dimensional analysis indicated that perception of differences in one component was influenced by the absolute level of the other component, if this was constant in the pair, or by the difference. Considerable variation among subjects in the nature and extent of this interference effect was observed. Individual differences scaling (INDSCAL) enabled a satisfactory consensus model to be obtained. An empirical relationship expressing the observed twocomponent difference scores in terms of one-component scores was derived. Increasing voltage level diminished perception of frequency difference. Higher frequency levels augmented perception of voltage difference. This relationship is a modification of the combinatorial model proposed by Krantz and Tversky (1975). Individual differences in the combinatorial process are allowed for by application of the subject weightings from the INDSCAL solution.     

Illusory colors promote interocular grouping during binocular rivalry

When dissimilar monocular images are presented separately to each of a person’s eyes, these images compete for visual dominance, with dominance of one image or the other alternating over time. While this phenomenon, called binocular rivalry, transpires, local image features distributed over space and between the eyes can become visually dominant at the same time; the resulting global figure implicates interocular grouping. Previous studies have suggested that color tends to influence the incidence of global dominance; in this study, we assess whether illusory color can also influence interocular grouping. To test this, we exploited the McCollough effect, an orientation-contingent color aftereffect induced by prolonged adaptation to different colors paired with different orientations. Results show that during binocular rivalry, illusory colors induced by the McCollough adaptation enhance strong interocular grouping relative to preadaptation testing, to an extent comparable in strength with the enhancement induced by real colors. Thus, illusory colors that are present only in an observer’s mind are sufficiently potent to influence low-level visual processes such as binocular rivalry.