Extraversion and Arousal Procrastination: Waiting for the Kicks

Procrastination is a prevalent and complex psychological phenomenon that has been defined as the purposive delay in beginning or completing a task. Given the potential implications for a broad range of situations, including both academic performance and safety sensitive occupations, it seems reasonable and judicious to systematically examine this phenomenon. While there is growing interest in procrastination, our understanding of underlying explanatory factors remains quite limited. Eysenck’s (1967) theory of personality, and in particular his biologically-based theory of extraversion, could shed light on this phenomenon. The purpose of this paper was to examine the relationship between extraversion and arousal procrastination. In accordance with Eysenck’s theory that extraverts tend to seek external sources of arousal, it was hypothesized that they would be more likely than introverts to engage in arousal procrastination. Participants completed a series of counterbalanced questionnaires measuring extraversion and procrastination. Results indicated that extraversion significantly predicted the engagement in this type of procrastination. Limitations, implications, and future research are discussed.     

Implicit causality bias in English: a corpus of 300 verbs

This study provides implicit verb causality norms for a corpus of 305 English verbs. A web-based sentence completion study was conducted, with 96 respondents completing fragments such as “John liked Mary because...” The resulting bias scores are provided as supplementary material in the Psychonomic Society Archive, where we also present lexical and semantic verb features, such as the frequency, semantic class and emotional valence. Our results replicate those of previous studies with much smaller numbers of verbs and respondents. Novel effects of gender and its interaction with verb valence illustrate the type of issues that can be investigated using stable norms for a large number of verbs. The corpus will facilitate future studies in a range of areas, including psycholinguistics and social psychology.     

Purkinje cell loss by OX7-saporin impairs acquisition and extinction of eyeblink conditioning

The current study examined the effects of globally depleting Purkinje cells in the cerebellar cortex with the immunotoxin OX7-saporin on acquisition and extinction of delay eyeblink conditioning in rats. Rats were given OX7-saporin or saline 2 wk before the start of eyeblink conditioning. The rats that reached a performance criterion of two consecutive days with 80% or greater conditioned responses were given 5 d of extinction training followed by 2 d of reacquisition training. Rats that received infusions of OX7-saporin had 77.2%-97.9% Purkinje cell loss and exhibited impaired acquisition and extinction. The amount of Purkinje cell loss was correlated with the magnitude of the acquisition and extinction impairments. The highest correlations between Purkinje cell number and the rate of acquisition were in lobule HVI and the anterior lobe. The highest negative correlation between Purkinje cell number and the percentage of conditioned responses during extinction was in the anterior lobe. The results indicate that cerebellar Purkinje cells, particularly in the anterior lobe and lobule HVI, play significant roles in acquisition and extinction of eyeblink conditioning.     

Children's strategies in producing three-dimensional relationships on a two-dimensional surface

It is a common task to give children a picture containing implicit depth cues and to require them to extract depth information from it. The cues are always selected from the adult repertoire; little is known about children's production of their own cues. In this experiment, 5- to 10-year-old children were required to draw one object behind another in a situation in which adults invariably produce the further object partially occluded by the nearer. The results were an age-related decline in the tendency to segregate the objects and an increase in the tendency to group the objects using partial occlusion, with a cross-over at 8 years. At all ages some children drew one object inside the boundary of the other. It is argued that the results are composed of two tendencies, a gradual mastery of discrete scaling phenomena (e.g., “up” on the page means “further”) within a given style, and a set of decisions to be made between incompatible styles.     

Selective phonemic and semantic coding in short-term recall

Probed recall of targets from six-word sequences containing either phonemically similar, semantically similar, or control (i.e., unrelated phonemically and semantically) stimuli was compared under two conditions of encoding. For the semantic encoding condition, in which all cues provided category information about targets to be recalled, semantic similarity interference effects and phonemic similarity facilitation effects were demonstrated. In the phonemic encoding condition, in which all targets were cued by words which rhymed with them, only phonemic similarity interference effects were found. These results were taken to provide further evidence contradictory to the coding-based dichotomization of primary and secondary memory, and to reflect the importance of selective coding strategies induced by task requirements as determinants of interference effects in short-term recall.     

Effects of causal belief for prior success or failure on preferences to delay gratification in task contingent versus task noncontingent conditions1

This study investigated how causal belief for prior success or failure affected preferences to delay gratifications in task contingent versus task noncontingent conditions. Success or failure on the Treatment Task and belief about the outcome were experimentally induced to lead fourth-and fifth-grade pupils to perceive task performance as resulting from one of four factors (Ability, Task Difficulty, Effort, or Luck). Thereafter, each subject chose between smaller, noncontingent rewards and delayed, larger rewards that were contingent on waiting only or on successful performance on tasks which varied in similarity to the initial task. As predicted, preferences to delay were not differentially affected by success or failure when subjects believed unstable factors of effort or luck caused the outcome. However, delay was affected by prior success or failure when the belief was that the outcome resulted from stable factors of ability or task difficulty, with subjects delaying more after success than following failure. Furthermore, the outcome predicted delay on tasks identical or similar to the Treatment Task whereas belief about causality predicted delay on the Different Task. Delay was greater by subjects with ability or effort inductions than by subjects with a luck induction.     

Extraretinal and retinal amplitude and phase errors during Filehne illusion and path perception

Pursuit eye movements give rise to retinal motion. To judge stimulus motion relative to the head, the visual system must correct for the eye movement by using an extraretinal, eye-velocity signal. Such correction is important in a variety of motion estimation tasks including judgments of object motion relative to the head and judgments of self-motion direction from optic flow. The Filehne illusion (where a stationary object appears to move opposite to the pursuit) results from a mismatch between retinal and extraretinal speed estimates. A mismatch in timing could also exist. Speed and timing errors were investigated using sinusoidal pursuit eye movements. We describe a new illusion--the slalom illusion--in which the perceived direction of self-motion oscillates left and right when the eyes move sinusoidally. A linear model is presented that determines the gain ratio and phase difference of extraretinal and retinal signals accompanying the Filehne and slalom illusions. The speed mismatch and timing differences were measured in the Filehne and self-motion situations using a motion-nulling procedure. Timing errors were very small for the Filehne and slalom illusions. However, the ratios of extraretinal to retinal gain were consistently less than 1, so both illusions are the consequence of a mismatch between estimates of retinal and extraretinal speed. The relevance of the results for recovering the direction of self-motion during pursuit eye movements is discussed.