Blind to Object Changes: When Learning the Same Object at Different Levels of Categorization Modifies Its Perception

The perceptual features people extract from objects depend on how they typically categorize them. It is now commonly acknowledged that the human perceiver can interact with the objects of his or her world at different, hierarchically organized levels of categorization. People who have learned to categorize an object as general or specific may therefore perceive different features in this object. We report two experiments that examined the hypothesis that the nature of categorization (general vs. specific) can influence the perceived properties of an identical distal object.     

The Beck Anxiety Inventory: Psychometric Properties with Older Adults

The assessment of anxiety disorders in late life is often hindered by the lack of measures specifically validated with older adults. Because anxiety manifestations may vary across age groups, it is important to design new instruments or validate existing measures with older adults. This study examined the psychometric properties of the Beck Anxiety Inventory (BAI) in a sample of 281 older adults who were community-dwelling (82.6%) or living in residential care facilities (17.4%). The mean total BAI score was 6.5 (SD = 7.2), indicating minimal anxiety symptomatology in this older sample. There was a trend for older subjects to score higher. Females scored higher than males, and subjects living in a residential facility scored higher than did community dwellers. Item-total correlations were in the moderate range and the internal consistency of the BAI was adequate (alpha = 0.89). A factor analysis yielded a six-factor structure accounting for 64.6% of the variance, with a somatic factor accounting for the largest portion of the variance (32.2%). Because somatic symptoms are more prevalent with aging, such symptoms should not be weighed as heavily in the total BAI score as cognitive or behavioral symptoms. The findings indicate that the BAI is a useful self-report scale for assessing anxiety symptomatology among older adults.     

Principal components analysis of sampled functions

This paper describes a technique for principal components analysis of data consisting ofn functions each observed atp argument values. This problem arises particularly in the analysis of longitudinal data in which some behavior of a number of subjects is measured at a number of points in time. In such cases information about the behavior of one or more derivatives of the function being sampled can often be very useful, as for example in the analysis of growth or learning curves. It is shown that the use of derivative information is equivalent to a change of metric for the row space in classical principal components analysis. The reproducing kernel for the Hilbert space of functions plays a central role, and defines the best interpolating functions, which are generalized spline functions. An example is offered of how sensitivity to derivative information can reveal interesting aspects of the data.This research was supported by Grant PA 0320 to the second author by the Natural Sciences and Research Council of Canada. We are grateful to the reviewers of an earlier version and to J. B. Kruskal and S. Winsberg for many helpful comments concerning exposition.     

Modeling,vicarious reinforcement and extraversion on blood donating in adults: Immediate and long-term effects

Studied the immediate and long-term effects of modeling on adult altruism using a quasi field experiment in a naturalistic setting. Forty-three female trainee occupational therapists aged 18-21 observed or did not observe a female model volunteer to donate blood. Modeling significantly increased the number of female observers who (a) also agreed to donate and (b) in turn actually gave their blood. The opportunity to donate blood occurred in a naturalistic situation on average six weeks after the commitment. It was concluded that observing a model could produce generalizable and durable behavior change in adults using an altruistic behavior of some cost to the individual. Personality and vicarious reinforcement effects however were not found.     

Self-dehumanisation in severe alcohol use disorder: Links with self-stigma and environmental satisfaction

Metadehumanisation (i.e., the perception of being considered as less than human by others) is proposed to be widespread in stigmatised populations, such as people with severe alcohol use disorder (SAUD). However, the relations between metadehumanisation, self-dehumanisation (i.e., the self-perception of being less than human), and stigmatisation (i.e., the negative taint applied to some groups) remain unexplored. The aim of this research is thus to investigate the relations between these processes. Metadehumanisation, self-dehumanisation, self-stigma (and its subdimensions) and environmental satisfaction were assessed in 120 inpatients with SAUD and analysed in a mediational model. Stigma awareness was positively associated with metadehumanisation, whereas environmental satisfaction was negatively associated with metadehumanisation. Stigma's application to the self was associated with increased self-dehumanisation. Self-stigma and self-dehumanisation are closely intertwined phenomena. Self-dehumanisation seems to follow a multi-step process suggesting that some steps, such as dehumanisation awareness, are missing from current models of dehumanisation.     

Channel surfing in the visual brain

Vision provides us with an ever-changing neural representation of the world from which we must extract stable object categorizations. We argue that visual analysis involves a fundamental interaction between the observer's top-down categorization goals and the incoming stimulation. Specifically, we discuss the information available for categorization from an analysis of different spatial scales by a bank of flexible, interacting spatial-frequency (SF) channels. We contend that the activity of these channels is not determined simply bottom-up by the stimulus. Instead, we argue that, following perceptual learning a specification of the diagnostic, object-based, SF information dynamically influences the top-down processing of retina-based SF information by these channels. Our analysis of SF processing provides a case study that emphasizes the continuity between higher-level cognition and lower-level perception.