A method for calibrating the spatial coordinates of a visual display to high accuracy

High-resolution CRT displays are subject togeometric distortion: lines that are straight in the internal coordinates of the graphics software and hardware are curved when projected onto a plane in the observer’s line of sight. As the available resolution of CRT screens increases, it becomes more difficult to measure and correct for this distortion. We present a simple, highly accurate method for determining the mapping between internal coordinates and the viewing plane. It requires that an observer, using a calibration program, adjust triples of displayed points until they are collinear. A metal straightedge placed between the observer and the screen aids in this judgment. We describe the calibration of an IBM Enhanced Graphics Display in high-resolution mode (350 × 640 pixels), and illustrate how to use the estimated mapping to choose internal coordinates to draw undistorted figures that are accurate to within 0.5 pixel. The method can be used to assess or to correct the accuracy of visual displays. The method is relevant to experiments in spatial vision, spatial perception, perception of dot patterns, and any application in which geometrically accurate stimuli are required.     

Rationality ideals and mentality

Mackenzie, this journal, this issue, convincingly shows that in certain dialogue games (commitment games) there are procedural restrictions similar to those that I impose on rationality idealizations. But, whereas my rationality analysis is set in the context of belief games, commitment games do not postulate beliefs. Is this significant? I suggest that mackenzie thinks that it is. There follow discussions of Psychologism and Behaviourism.     

Long latency auditory evoked potentials

Experiment 1 elicited the P1, N1, P2, and N2 components of the long latency auditory evoked potential (AEP) using a 1000 Hz tone presented at 30, 50, or 70 dB SPL and 1-, 3-, or 5- second inter-stimulus intervals to assess the relative effects of the combination of these variables on component amplitude and latency. Four blocks of 16 tone presentations each were recorded from each subject to determine if changes in the AEP would occur because of short-term habituation. Both stimulus factors interacted significantly in a systematic fashion for the amplitude measures, with increases in latency also associated with increases in intensity and inter-stimulus interval. Only minor changes across the four trial blocks for either the amplitude or latency measures were observed over the various stimulus presentation conditions. Experiment 2 employed the same tone stimulus presented at 50 dB SPL and a 3-second inter-stimulus interval. Eight blocks of 64 trials were recorded from each subject on each day for four days to investigate long-term habituation effects. No substantial changes in any of the component amplitudes or latencies were obtained across the 32 trial blocks. It was concluded that intensity and inter-stimulus interval interact to determine AEP amplitude as well as latency values and that the constituent components do not change appreciably with repeated stimulus presentations, even after several days.     

Maternal handling and motor development: an intracultural study

Citing a distinction between informal and formal routines used by mothers in handling their infants, we examined formal handling routines, in which the caregiver acts in a pedagogical manner; these routines are widespread in many non-Western countries. We hypothesised that formal handling serves to facilitate gross motor development during early infancy. To examine this hypothesis, the effects of a Jamaican formal handling routine on a broad range of developmental outcomes was examined. Results showed that the effects were specific to early gross motor development and in particular to postural control along the vertical axis of the body. Information is also provided on other aspects of Jamaican child care. It seems that the handling routine forms part of a folk (developmental) medicine system and may serve not only to promote child health but also as a sort of developmental neurological examination.     

Neutrality, interpretation, and therapeutic intent.

Neutrality is a central concept within the theory of psychoanalytic technique. We spell out the major controversies in which the concept has become embroiled, and provide a definition that we believe coincides with actual psychoanalytic practice. We discuss its merits and weaknesses, noting also the negative consequences of relying on older definitions. We relate neutrality to the interpretive process, indicating ways interpretation protects neutrality and is made more effective by it. We discuss the complex and controversial relation between neutrality and the analyst's therapeutic intent.     

Malevolent object representations in borderline personality disorder and major depression.

To study malevolent representations, earliest memories were reliably coded on scales of affect tone. Ss were diagnosed with borderline personality disorder: 31 without and 30 with concurrent major depression. Nonborderline comparison subjects had either major depressive disorder (n = 26) or no psychiatric diagnosis (n = 30). Borderline subjects were discriminated from comparison subjects by their more malevolent representations; they more frequently produced memories involving deliberate injury; and they portrayed potential helpers as less helpful. Results suggest the diagnostic significance of malevolent representations, which need to be explained by any theory of borderline personality disorder.     

When depression breeds contempt: reassurance seeking, self-esteem, and rejection of depressed college students by their roommates.

To test Coyne's (1976b) theory of depression, students' levels of depressive symptoms, reassurance seeking, and self-esteem were assessed at Time 1, and their same-gender roommates' appraisals of them were assessed 5 weeks later. Mildly depressed students engaged in the type of reassurance seeking described by Coyne. Among men, but not women, mildly depressed students were rejected if they strongly sought reassurance and had low self-esteem but not if they did not seek reassurance or had high self-esteem. Although induction of depressed symptoms in roommates did occur, this contagion effect did not account for the depression-rejection relationship. The prediction that unsupportive, intolerant, or unempathic others would be particularly likely to respond with rejection to reassurance-seeking depressed students with low self-esteem received partial support. Implications for future work on the interpersonal aspects of depression are discussed.     

Forms of memory failure in schizophrenia.

Effortful and automatic memory task performances were examined in 36 schizophrenic patients and 18 normal control Ss. Tasks included free recall, recognition, and frequency estimation. Patients demonstrated impairment in recall, in recognition, in semantic encoding, and in frequency estimation. Deficits were observed across tasks despite differences in attentional demands. The results suggest a basic compromise of memory function, which is consistent with recent neuroimaging evidence of structural or physiological abnormalities in frontal and temporal lobe structures in schizophrenia.     

Interpersonal underpinnings of request strategies: general principles and differences due to culture and gender.

Several hypotheses derived from P. Brown and Levinson's (1987) politeness theory were tested with Ss from the United States and Korea. Ss imagined themselves in situations in which they were to make a request. They then indicated exactly what they would say in each situation and what their perceptions of the request size, the hearer's power, and the closeness of their relationship with the hearer were. Consistent with P. Brown and Levinson's theory, power, distance, and size contributed significantly to politeness. Significant predictor variable interactions suggested that an additive model is not appropriate. Finally, there was evidence of cultural and gender differences in the weighting of these predictor variables. These differences can partially account for cultural and gender differences in language use.