The time course of visual afterimages: data and theory

Sequential viewing of two orthogonally related patterns produces an afterimage of the first pattern (Vidyasagar et al, 1999 Nature 399 422-423; Francis and Rothmayer, 2003 Perception and Psychophysics 65 508-522). We investigated how the timing between the first stimulus (a vertical bar grating) and the second stimulus (a horizontal bar grating) affected the visibility of the afterimage (a perceived vertical grating). As the duration from offset of the first stimulus increased, reports of afterimages decreased. Holding fixed the total time from offset of the first stimulus and increasing the duration from offset of the second stimulus while decreasing the time between the first and second stimuli, caused a decrease in afterimage reports. We interpret this finding in terms of Grossberg's BCS - FCS (boundary contour system--feature contour system) theory. In this theory, the afterimage percept is the result of color complement after-responses in the FCS system interacting with orientation after-responses in the BCS system. The two types of after-responses interact at a stage of neural filling-in to produce the afterimage percept. As the duration between the stimuli increases, the color after-responses weaken so that visible filling-in is less likely to occur. A similar effect occurs for the orientation after-responses but at a faster time scale. Simulations of the model match the experimental data.     

A covariance structure analysis of employees' response to performance feedback

This longitudinal study used D. R. Ilgen, C. D. Fisher, and M. S. Taylor's (1979) feedback process model as a theoretical framework to determine whether a sequential chain of cognitive variables mediates an individual's response to performance feedback. One hundred two employees were surveyed 2 weeks after their performance appraisal, and performance was assessed 11 months later at the end of the review cycle. Covariance structure analysis supported the convergent and discriminant validity of the constructs underlying the model and the constellation of structural relationships. A set of cognitive variables was found to completely mediate the relationship between an individual's receipt and response to feedback. Implications for the feedback process and future research are discussed.     

Specific-token effects in screening tasks: possible implications for aviation security

Screeners at airport security checkpoints perform an important categorization task in which they search for threat items in complex x-ray images. But little is known about how the processes of categorization stand up to visual complexity. The authors filled this research gap with screening tasks in which participants searched for members of target categories in visual displays. The authors found that when targets were sampled with replacement and repetition, participant screeners relied on recognizing familiar targets and had great difficulty using category-general knowledge. The authors observed a "heartbeat" in detection performance--it improved while test images repeated but dropped sharply when unfamiliar targets from the same categories appeared. This reliance on familiarity illuminates the processes of categorization under conditions of visual complexity and suggests limits on those processes. This reliance also has implications for the training and evaluation of screeners in the field.     

A comparison of the validity of the five-factor model (FFM) personality disorder prototypes. Using FFM self-report and interview measures

Recent studies have demonstrated that personality disorders (PDs) can be assessed via a prototype-matching technique, which enables researchers and clinicians to match an individual's five-factor model (FFM) personality profile to an expert-generated prototype. The current study examined the relations between these prototype scores, using interview and self-report data, and PD symptoms in an outpatient sample (N = 115). Both sets of PD prototype scores demonstrated significant convergent validity with PD symptom counts, suggesting that the FFM PD prototype scores are appropriate for use with both sources of data.     

Manipulations that disrupt generative processes decrease conformity to examples: evidence from two paradigms

Participants in six experiments viewed experimenter-provided examples of space creatures (Experiments 1-3) or nonwords (Experiments 4-5b) and then created their own novel space creatures or nonwords. Consistent with previous research, people borrowed many of the features found in the examples despite instructions to avoid using any aspects of the experimenter's examples. However, requiring people to include a designated shape in their space creatures or a designated letter in their nonwords attenuated this effect. Additionally, the type of shape or letter (conventional versus unconventional) also affected conformity. These results suggest that the strategies that people use to create novel products can affect the level of conformity and also highlight the importance of adopting unconventional, or at the very least, new strategies when creating new products.     

Five-factor model prototypes for personality disorders: the utility of self-reports and observer ratings

The current study examined the prototype-matching technique for using the five-factor model (FFM) of personality to assess personality disorders (PDs) and their correlates. The sample was composed of 69 psychiatric patients, most of whom suffered from affective or anxiety disorders. The participants were predominantly outpatients (78%), Caucasian (94%), and women (58%). NEO Personality Inventory (NEO-PI) data from these patients and informants were available for deriving PD prototype scores. The results supported four conclusions. First, the FFM prototype-matching method is useful for clinical samples. Second, agreement between self-reports and information from significant others (SOs) using this method is good compared to previous results. Third, this agreement varies systematically with the observability of the PD criteria. Fourth, the value of self- and other-reported personality information depends on the rating source of the outcome variables. Other-reported information provides incremental utility in predicting impairment and interpersonal distress rated by clinicians and significant others.