Effects of vision and haptics on categorizing common objects

Most research on object recognition and categorization centers on vision. However, these phenomena are likely influenced by the commonly used modality of touch. The present study tested this notion by having participants explore three-dimensional objects using vision and haptics in naming and sorting tasks. Results showed greater difficulty naming (recognizing) and sorting (categorizing) objects haptically. For both conditions, error increased from the concrete attribute of size to the more abstract quality of predation, providing behavioral evidence for shared object representation in vision and haptics.     

Fechner, information, and shape perception

How do retinal images lead to perceived environmental objects? Vision involves a series of spatial and material transformations—from environmental objects to retinal images, to neurophysiological patterns, and finally to perceptual experience and action. A rationale for understanding functional relations among these physically different systems occurred to Gustav Fechner: Differences in sensation correspond to differences in physical stimulation. The concept of information is similar: Relationships in one system may correspond to, and thus represent, those in another. Criteria for identifying and evaluating information include (a)?resolution, or the precision of correspondence; (b)?uncertainty about which input (output) produced a given output (input); and (c)?invariance, or the preservation of correspondence under transformations of input and output. We apply this framework to psychophysical evidence to identify visual information for perceiving surfaces. The elementary spatial structure shared by objects and images is the second-order differential structure of local surface shape. Experiments have shown that human vision is directly sensitive to this higher-order spatial information from interimage disparities (stereopsis and motion parallax), boundary contours, texture, shading, and combined variables. Psychophysical evidence contradicts other common ideas about retinal information for spatial vision and object perception.     

Age,working memory,and the Tower of London task

The current study explores the role of three components of working memory in age differences in an executive task, the Tower of London (TOL). The TOL task is sensitive to frontal lobe damage, and is widely used to measure planning ability. Dual tasks were used to test the involvement of the phonological loop (articulatory suppression), visuospatial buffer (pattern tapping), and central executive (random generation) in age effects on the TOL. Older adults showed greater reliance than young on domain-specific verbal and spatial memory components in performing the TOL. In terms of executive function, qualitatively different interference patterns were seen in young and old participants. However, the validity of using random generation tasks to assess executive function in older populations can be questioned. For older participants, performing the TOL loads all components of working memory, whereas for the younger participants the TOL more specifically loads executive functioning.     

Telling stories: The structure of adults' narratives

Abstract

Adults' narratives were analysed to study life-span changes in their structure. The narratives were collected from a group of adults in their 60s, 70s, and 80s. Four separate analyses were performed on the narratives' (1) hierarchical structure, (2) syntactic structure, (3) propositional content, and (4) cohesion. Age-group differences were obtained for the measures of hierarchical structure, syntactic structure, and cohesion. Further analyses revealed that the structural complexity of the narratives influenced their syntactic structure and cohesion. Interactions between the effects of age group and structural complexity suggest that elderly adults minimise the syntactic complexity of their narratives, reducing their cohesion, when producing structurally complex narratives. Finally, ratings of the quality of the narratives were strongly correlated with their structural complexity, suggesting that telling a “good” story involves constructing complex plots.     

Job context, selection decision outcome, and the perceived fairness of selection tests: biodata as an illustrative case

S. W. Gilliland (1993) has proposed a model of perceived selection system fairness to help understand applicants' prehire and posthire behavior. The present study aimed to verify and extend his framework by investigating the role of job context in the formation of fairness perceptions of biodata. A sample of 255 students (108 men, 147 women) completed an operational biodata instrument, believing that it would be used to hire persons for either international, local, or unspecified entry-level managerial positions. Participants were then presented with outcome information (selected or rejected for further consideration). Consistent support was found for the research hypotheses derived from the Gilliland model. Participants' perceptions of the fairness and job relatedness of biodata were affected by the selection context and decision outcome. The importance of considering selection context in assessments of perceived test fairness is discussed.     

The use of schematic knowledge about sources in source monitoring

Source monitoring refers to mental processes leading to attributions regarding the origin of information. We tested Johnson, Hashtroudi, and Lindsay's (1993) assumption that prior source-relevant knowledge is used in some source-monitoring tasks. In two experiments using different domains of schematic knowledge, two sources presented information that was expected for one source and somewhat unexpected for the other. In a later source-monitoring test, participants decided whether items had been presented by Source A, by Source B, or were new. The results of both experiments show that source identification is better for expected items than for somewhat unexpected items. Multinomial modeling analyses revealed that when participants do not remember the source of information, they guess that it was presented by the expected source. These results provide evidence for the claim that source monitoring can be based on prior knowledge and support a guessing hypothesis.     

Chronically increased Gsalpha signaling disrupts associative and spatial learning

The cAMP/PKA pathway plays a critical role in learning and memory systems in animals ranging from mice to Drosophila to Aplysia. Studies of olfactory learning in Drosophila suggest that altered expression of either positive or negative regulators of the cAMP/PKA signaling pathway beyond a certain optimum range may be deleterious. Here we provide genetic evidence of the behavioral and physiological effects of increased signaling through the cAMP/PKA pathway in mice. We have generated transgenic mice in which the expression of a constitutively active form of Gsalpha (Gsalpha* Q227L), the G protein that stimulates adenylyl cyclase activity, is driven in neurons within the forebrain by the promoter from the CaMKIIalpha gene. Despite significantly increased adenylyl cyclase activity, Gsalpha* transgenic mice exhibit PKA-dependent decreases in levels of cAMP due to a compensatory up-regulation in phosphodiesterase activity. Interestingly, Gsalpha* transgenic mice also exhibit enhanced basal synaptic transmission. Consistent with a role for the cAMP/PKA pathway in learning and memory, Gsalpha* transgenic mice show impairments in spatial learning in the Morris water maze and in contextual and cued fear conditioning tasks. The learning deficits observed in these transgenic mice suggest that associative and spatial learning requires regulated Gsalpha protein signaling, much as does olfactory learning in Drosophila.     

Effects of counseling Ashkenazi Jewish women about breast cancer risk

The goal of this study was to determine whether genetic counseling or psychosocial group counseling provided to Ashkenazi women can reduce breast cancer worry, cancer risk perception, and interest in having genetic testing. Women (N=211) were randomized to receive individual genetic risk counseling, to receive a group psychosocial group counseling, or to serve as a control group. The authors found that both counseling methods reduced cancer worry, lowered perceptions of breast cancer risk, and decreased interest in having genetic testing. Counseling can help women gain a more accurate perception of their risk, expose them to the benefits and limitations of genetic testing, and reduce their worry about cancer.