Notes on discounting

In general, if a variable can be expressed as a function of its own maximum value, that function may be called a discount function. Delay discounting and probability discounting are commonly studied in psychology, but memory, matching, and economic utility also may be viewed as discounting processes. When they are so viewed, the discount function obtained is hyperbolic in form. In some cases the effective discounting variable is proportional to the physical variable on which it is based. For example, in delay discounting, the physical variable, delay (D), may enter into the hyperbolic equation as kD. In many cases, however, the discounting data are not well described with a single-parameter discount function. A much better fit is obtained when the effective variable is a power function of the physical variable (kDS in the case of delay discounting). This power-function form fits the data of delay, probability, and memory discounting as well as other two-parameter discount functions and is consistent with both the generalized matching law and maximization of a constant-elasticity-of-substitution utility     

Directional uncertainty in visually guided pointing

Studies of the relationship between stimulus-response uncertainty and reaction times indicate three qualitatively different functions: Hick's law, simple-choice step function, or flat curve (no effect at all). The extent of stimulus-response S-R) compatibility appears to interact with the effects of uncertainty on response times. One possible hypothesis regarding these various S-R uncertainty functions is that uncertainty will have an effect whenever the stimuli and their associated responses are not within the same egocentric spatial coordinates. We tested this hypothesis in 5 undergraduate participants (2 men, M age 18.7 yr., range 18-20) by investigating the time-course of pointing to peripherally located visual targets under four different levels of uncertainty (1, 2, 4, or 8 possible locations). Surprisingly, the resulting response function does not match any of those previously reported. Visually guided pointing produced a quadratic reaction time function as S-R uncertainty increases in log2 steps from 1 to 8.     

Conceptions of career choice and attainment: Developmental levels in how children think about careers

Children’s Conceptions of career choice and attainment were evaluated in two studies to test whether reasoning levels varied by grade level (Studies 1 and 2) and perspective-taking complexity (Study 2). Results indicated that younger children (Grade K) were more likely to use reasoning strategies associated with fantasy and magical thinking and older children (Grade 6) were more likely to consider personal interests, abilities, and job requirements. Study 2 replicated these results and also found that children evaluated as able to use more complex perspective-taking reported higher reasoning levels when discussing their Conceptions of career choice and attainment.     

Rate, Probability and Matching: Comments on ��The Identities Hidden in the Matching Laws, and Their Uses�� by David Thorne

David Thorne's (2010) article, “The Identities Hidden In The Matching Laws, And Their Uses” performs a valuable service in pointing out alternative expressions of matching. However, some identities tend to obscure rather than illuminate empirical relationships. Three such problematic instances are discussed: interresponse time as a function of interval and ratio schedule parameters; probability equality as implying rate matching; the apparent simplicity of probabilistic functions, as opposed to response rate functions, of reinforcement rate.     

Rate, probability and matching: comments on "The identities hidden in the matching laws, and their uses" by David Thorne

David Thorne's (2010) article, "The identities hidden in the matching laws, and their uses" performs a valuable service in pointing out alternative expressions of matching. However, some identities tend to obscure rather than illuminate empirical relationships. Three such problematic instances are discussed: interresponse time as a function of interval and ratio schedule parameters; probability equality as implying rate matching; the apparent simplicity of probabilistic functions, as opposed to response rate functions, of reinforcement rate.     

The temporal contiguity effect predicts episodic memory performance

One way to study the associative processes at work during episodic memory is to examine the order of participant responses, which reveal the strong tendency to transition between temporally contiguous or semantically proximal items on the study list. Here, we assessed the correlation between participants’ recall performance and their use of semantic and temporal associations to guide retrieval across nine delayed free recall studies. The size of the participants’ temporal contiguity effects predicted their recall performance. When interpreted in terms of two models of episodic memory, these results suggest that participants who more effectively form and retrieve associations between items that occur nearby in time perform better on episodic recall tasks. Sample code may be downloaded as a supplement for this article from http://mc.psychonomic-journals.org/content/ supplemental.     

Alcohol‐related violence defined by ultimate goals: a qualitative analysis of the features of three different types of violence by intoxicated young male offenders

Based upon a functional approach to understanding aggression, we aimed to identify the occurrence of and to describe the features of three types of alcohol‐related violence defined a priori by ultimate goals: (1) violence in pursuit of nonsocial profit‐based goals, (2) violence in pursuit of social dominance goals, and (3) violence as defence in response to threat. A sample of 149 young men with offences of violence that were alcohol related was interviewed. Cases were classified and detailed information from the first ten cases in each class (N=30) was subjected to thematic analysis. Intoxicated violence in pursuit of nonsocial profit‐based goals was opportunistic and motivated by the desire for more alcohol or drugs. Violence, in these cases, although serious, appeared to be brief. Intoxicated violence in pursuit of social dominance goals was typically precipitated by past or current insult or injury, and was accompanied by strong anger and an adrenaline rush. Attacks were ferocious, and robbing the victim was not uncommon, perhaps to inflict additional humiliation. Feelings of pride and satisfaction were typical and expressions of remorse were uncommon. Regarding intoxicated violence as defence in response to threat, attacks were often expected, and in some cases the respondent made a pre‐emptive strike. Weapon use was common in this group. Fear was experienced, but so too was anger. Feelings of excitement were not reported and remorse was common. Further validation of these types is warranted, and the potential implications of these findings for prevention and treatment are discussed. Aggr. Behav. 36:67–79, 2010. © 2009 Wiley‐Liss, Inc.     

The evolving systems approach to creative work

This study investigated the connection between drawing skill and artistic creativity in relation to age groups and levels of artistic involvement among 223 Chinese primary, secondary, and university students in Hong Kong. Based on the fantasy drawing task, visual-artist judges made expert judgments on students' drawing skill and artistic creativity. There was substantial correlation between drawing skill and artistic creativity among children, adolescents, and young adults, even when artistic involvement was controlled in the partial correlation analyses. The results of correlational and regression analyses suggested that drawing skill contributed most significantly to the prediction of artistic creativity throughout the years at different stages of development, but artistic involvement became more important, especially in young adulthood. Implications of the findings on the skill–creativity relationship for arts education and the directions for future research are discussed.