Using logistic regression to estimate delay-discounting functions

The monetary choice questionnaire (MCQ) and similar computer tasks ask preference questions in order to ascertain indifference, the perceived equivalence of immediate versus larger delayed rewards. Indifference data are then fitted with a hyperbolic function, summarizing the decline in perceived value with delay time. We present a fitting method that estimates the hyperbolic parameterk directly from survey responses. Binary preferences are modeled as a function of time (X₂) and a transformed reward ratio (X ₁), yielding logistic regression coefficients β₂ and β₁. The hyperbolic parameter emerges ask = β₂/β₁, where the logistic predictedp = .5 (the definition of indifference). The MCQ was administered to 1,073 adolescents and was scored using both standard and logistic methods. The means for ln(k) were similar (standard, −4.53; logistic, −4.51), and the results were highly correlated (ρ = .973). Simulated MCQ data showed thatk was unbiased, except where β₁ ≥ −1, indicating a vague survey response. Jackknife standard errors provided excellent coverage.     

Differential effects of age on prospective and retrospective memory tasks in young, young-old, and old-old adults

Remembering to do something in the future (termed prospective memory) is distinguished from remembering information from the past (retrospective memory). Because prospective memory requires strong self-initiation, Craik (1986) predicted that age decrements should be larger in prospective than retrospective memory tasks. The aim of the present study was to assess Craik's prediction by examining the onset of age decline in two retrospective and three prospective memory tasks in the samples of young (18-30 years), young-old (61-70 years), and old-old (71-80 years) participants recruited from the local community. Results showed that although the magnitude of age effects varied across the laboratory prospective memory tasks, they were smaller than age effects in a simple three-item free recall task. Moreover, while reliable age decrements in both retrospective memory tasks of recognition and free recall were already present in the young-old group, in laboratory tasks of prospective memory they were mostly present in the old-old group only. In addition, older participants were more likely to report a retrospective than prospective memory failure as their most recent memory lapse, while the opposite pattern was present in young participants. Taken together, these findings highlight the theoretical importance of distinguishing effects of ageing on prospective and retrospective memory, and support and extend the results of a recent meta-analysis by Henry, MacLeod, Phillips, and Crawford (2004).     

Predictors to Happiness in Primary Students: Positive Relationships or Academic Achievement

This study aimed to examine the role of positive relationships and academic achievement in predicting student well-being, i.e. subjective happiness. This study employed a longitudinal design with two waves of data collection on a sample of 786 primary school students in Hong Kong. Students completed questionnaires on parent-child relationship, teacher-student relationship, peer relationship, academic achievement, and happiness at the beginning and end of the school year. Path analysis was used for data analysis. The results indicated that Time 1 parent-child relationship and peer relationship were associated with Time 2 academic achievement, after controlling for Time 1 academic achievement. However, only Time 1 parent-child relationship was predictive of Time 2 happiness. Time 2 academic achievement was a mediator between Time 1 parent-child relationship and peer relationship and Time 2 happiness. Furthermore, girls reported higher levels of academic achievement when they perceived better peer relationship than did boys, and girls were happier when they had higher levels of academic achievement than were boys. The results suggested the need to put in place strategies to enhance parent-child relationship, peer relationship, and a harmonious classroom.

     

Presentation modality,rehearsal-prevention conditions,and auditory confusions in tests of short-term memory

Ss were presented four-letter sequences either auditorily or visually and asked for ordered recall after 0, 2.1, 4.2, 8.4, or 12.6 sec of digit categorization. Three different rehearsal-prevention conditions were required during presentation of the memory set: categorizing, suppressing (saying "dah"), or pronouncing each letter. Recall was worst after categorizing, best after pronouncing. Auditory presentation led to better recall after no delay but more rapid forgetting than visual presentation, regardless of the rehearsal-prevention condition. These results, and analyses of auditory confusions, are inconsistent with a view of memory which asserts that sensory information is encoded auditorily regardless of presentation modality or vocalization behavior during presentation.     

Thought-shape fusion in anorexia nervosa: an experimental investigation

Cognitive biases and cognitive distortions have been implicated as important factors in the development and maintenance of many disorders. The concept of thought-shape fusion (TSF) in eating disorders was developed by Shafran, Teachman, Kerry, and Rachman (British Journal of Clinical Psychology 38 (1999) 167) as a variant of thought-action fusion, described by Shafran, Thordarson and Rachman (Journal of Anxiety Disorders 10 (1996) 379). TSF occurs when thinking about eating certain types of food increases a person's estimate of their shape and/or weight, elicits a perception of moral wrongdoing, and/or makes the person feel fat. Shafran et al. (1999) examined both the psychometric and experimental properties of TSF in an undergraduate sample. This paper reports an extension of this work to a clinical group (N=20) of patients with anorexia nervosa. After completing a set of relevant questionnaires, participants were asked to think about a food which they considered extremely fattening. They were then asked to write out the sentence, "I am eating--.", inserting the name of the fattening food in the blank. After being asked to rate their anxiety, guilt, feelings about their weight, morality, etc., participants were given the opportunity to neutralize their statement in any way they chose. The majority of the participants neutralized in ways consistent with the findings of Shafran et al. (1999). The results are discussed in terms of cognitive-behavioural formulations of eating disorders, and of the influence of cognitive biases and cognitive distortions on the processing of information relevant to food, weight and shape in anorexia nervosa.     

The accessibility of characters in single sentences: proper names,common nouns,and first mention

Accessibility of characters in two-character sentences (e.g., The butler helped Calvin at the wedding reception) was investigated with a probe recognition task. Probes were either the first character (e.g., butler) or the second character (e.g., Calvin) in a sentence and were designated by proper names or common nouns crossed with name or noun nonprobes. Results show that (1) probes in first position are more accessible than those in second position, but not when noun probes are paired with name nonprobes, (2) characters designated by names are generally more accessible than those designated by nouns, and (3) the first name in a sentence is more available than other characters, regardless of position. Thus, accessibility of characters in a sentence seems dependent on discourse function, with named characters seen as main characters, rather than on nondiscourse-related factors, such as temporal distinctiveness.     

Do Positive Self-Perceptions Have a “Dark Side”? Examination of the Link between Perceptual Bias and Aggression

The hypothesis that positive self-perceptions may have a dark side was investigated in the present study by examining the relationship between positively biased self-perceptions and aggression. Ratings of actual and perceived social acceptance of third-grade (n = 278), fourth-grade (n = 260), and fifth-grade (n = 321) students were compared to form a measure of perceptual bias. Peers provided nominations for overt and relational aggression. Gender differences were found for aggression (males were more overtly and relationally aggressive than females) but not perceptual bias. African-American children held more positive perceptions of their social acceptance and were perceived by peers as more aggressive than Caucasian children. Even after controlling for the effects of gender and ethnicity, more positively biased perceptions were associated with more peer nominations for overt and relational aggression. Contrary to an optimal range of bias hypothesis, even moderately positive self-perceptions were associated with elevated levels of aggression.     

Word Frequency Effects on the Processing of Subject–Verb Number Agreement

This paper examines the role of word frequency in the computation of subject–verb number agreement. Previous research in both production and comprehension has demonstrated that processing difficulties can arise in sentence structures containing a singular subject noun followed by a plural distractor noun, as in The key to the cabinets.¨ A whole sentence reading task was employed to determine whether the relative frequency with which the distractor noun appears in its singular or plural form would affect the degree of processing difficulty experienced by readers. Results suggest that the agreement process is, indeed, sensitive to this factor and this finding is compatible with activation-based accounts of the implementation of number agreement.     

Attributional Style, Self-Esteem, and Human Immunodeficiency Virus: A Test of the Hopelessness and Self-Esteem Theories of Depression

Research on the hopelessness and self-esteem theories of depression (Abramson, Metalsky, & Alloy, 1989; Metalsky, Joiner, Hardin, & Abramson, 1993) suggests that HIV-infected persons with depressotypic attributional style (AS) and low self-esteem (SE) may be at risk for onset of a syndrome referred to as hopelessness depression (HD). In a prospective study conducted to test these theories, measures of anxiety and depression, AS, and SE were administered to 85 HIV+ and 43 HIV– men; symptoms were reassessed 6 months later. Results indicated that: (1) The interaction of AS, SE, and HIV status predicted change in HD symptoms, but not overall depression or anxiety symptoms; (2) HIV+ men with depressotypic AS and high SE had increased HD symptom levels while other men with high SE had decreased HD symptom levels; (3) HD symptoms remained stable over the 6-month interval among men with low SE; and (4) High SE predicted decreases in anxiety symptoms among HIV– men, but not among HIV+ men. Contrary to the study hypothesis, these findings suggest that among individuals with life-threatening illnesses such as HIV infection, those with depressotypic AS and high SE may be at highest risk for onset of HD.