Effects of the contingency for homework submission on homework submission and quiz performance in a college course

Effects of the contingency for submission of homework assignments on the probability of assignment submission and on quiz grades were assessed in an undergraduate psychology course. Under an alternating treatments design, each student was assigned to a points condition for 5 of 10 quiz-related homework assignments corresponding to textbook chapters. Points were available for homework submission under this condition; points were not available under the no-points condition. The group-mean percentage of homework assignments submitted and quiz grades were higher for all chapters under the points condition than in the no-points condition. These findings, which were replicated in Experiment 2, demonstrate that homework submission was not maintained when the only consequences were instructor-provided feedback and expectation of improved quiz performance.     

Support for an explanation of the guidance effect in motor skill learning

The authors investigated whether the knowledge of results (KR) schedule influences the extent to which intrinsic feedback is noticed and used. Fifty-six participants received KR that was either delayed over 2 trials (Delay-2) or provided directly after each trial (Delay-0) during 160 trials of an unfamiliar aiming task. No-KR retention tests were given after 80 trials and 1 min and 24 hr after the end of acquisition. After retention, all participants were questioned about their use of intrinsic feedback during practice and whether those sources changed as a function of practice. The Delay-2 group performed significantly less accurately on the 1st and last blocks of acquisition trials but showed a significantly smaller performance decline from acquisition to retention. Moreover, the Delay-2 group noticed and used a greater variety of intrinsic feedback sources and its members were more likely to report that their usage changed with practice.     

Labor supply and consumption of food in a closed economy under a range of fixed- and random-ratio schedules: tests of unit price

The behavioral economic concept of unit price predicts that consumption and response output (labor supply) are determined by the unit price at which a good is available regardless of the value of the cost and benefit components of the unit price ratio. Experiment 1 assessed 4 pigeons' consumption and response output at a range of unit prices. In one condition, food was available according to a range of fixed-ratio schedules, whereas in the other condition, food was available according to a range of random-ratio schedules. Consistent with unit price predictions, consumption and response output were approximately equivalent across schedule types within the lower range of unit prices. However, at Unit Prices 64 (ratio value = 192) and greater, considerably more consumption and response output were observed in the random-ratio condition. Experiment 2 replicated these findings with 4 pigeons using the rapid demand curve assay procedure that is commonly used in the behavioral economics literature. Findings are integrated with two mathematical models of behavior under variable reinforcer delays.     

Distractor familiarity leads to more efficient visual search for complex stimuli

Previous reports suggest that distractor familiarity plays an important role in determining visual search efficiency. However, the specific tasks used in those studies limit the extension of their findings to real-world situations and everyday images. In the present study, subjects engaged in a prolonged period of search experience as a control of their level of familiarity with a large set of target and distractor images. Reaction times and search slopes decreased dramatically over this period, especially for trials with a large target eccentricity and many distractors. Following extended practice, search among familiar distractors was more efficient than search among unfamiliar distractors. Furthermore, we found that familiar targets were located more efficiently than unfamiliar targets and that subjects were faster at locating targets that they had experienced in the majority of the search trials. These results show that prolonged visual experience facilitates processing of both target and distractor items during search.     

An Analysis of Pride Systems and the Dynamics of Faith

Pride, in Western Christianity, has long been recognized as a vice and deadly sin. In this article, individual and communal pride is understood as emerging from, and supported by, a system of hierarchical valuations, which provides a subjective and intersubjective sense of self-worth along with a sense of power and privilege. A pride system is linked to, and supported by, stories and rituals that omnipotently confirm individual and communal status and power. This complex system is accompanied by a particular faith dynamic that benefits its members, yet alienates those deemed to be of lesser value. While positive valuations support a persons (and communitys) sense of self-esteem and are, more often than not, important for a sense of trust, group loyalty, and community, they are also accompanied by negative appraisals that are projected onto an other. This other is alienated from the privileges and power of those who identify with, and own, the positive valuations. Pride systems, then, are good to the extent that they shore up a sense of self and community and bad, or inherently deadly, to the extent that goodness depends on the subtle or overt alienation of a person or group.     

Psychology of learning: a new approach to study behavior of Rhodnius prolixus stal under laboratory conditions

Conditioning methodologies associated with the psychology of learning are suggested as a new strategy to investigate behavior of the assassin bug Rhodnius prolixus, which is the main vector of Chagas disease in Venezuela. Chagas disease is the fourth leading cause of death in Latin America, as it causes severe chronic illness and approximately 43,000 deaths per year. To illustrate this strategy, two preliminary experiments are reported. In the first, Pavlovian conditioning was examined by pairing an olfactory conditioned stimulus with a temperature unconditioned stimulus. A temperature of 42 degrees C elicits a complex behavioral sequence in R. prolixus consisting of proboscis extension and crawling. Over the course of 12 training trials, this behavioral sequence was not elicited by an olfactory conditioned stimulus. In the second experiment, a latent inhibition paradigm was used to pre-expose R. prolixus to an olfactory conditioned stimulus before pairing the odor with temperature. Over the course of training, an effect of pre-exposure was found. Suggestions for research are discussed and potential conditioned and unconditioned stimuli identified.     

Revisiting within-modality and cross-modality attentional blinks: effects of target-distractor similarity

When two masked targets (T1 and T2) require attention and are presented within half a second of each other, the report accuracy for T2 is reduced, relative to when the two targets are presented farther apart in time. This effect is known as the attentional blink (AB). Potter, Chun, Banks, and Muckenhoupt (1998) argued that all AB-like effects observed when at least one of the targets was presented outside of the visual modality did not represent true instances of the AB, but instead were artifacts of task-set switching. However, in the Potter et al. experiments the presence or absence of task-set switching opportunities was confounded with the T2 task, as well as the alphanumeric class of T2 with respect to the distractors. In the present experiment, we examine the influence of T1 alphanumeric class, T2 alphanumeric class, and switching operations in a fully crossed design that unconfounds these factors. In contrast to the conclusions of Potter et al., the present results suggest that the T2 alphanumeric class can account for the pattern of ABs observed across conditions, without necessarily implicating a separate switch cost. The implications for theoretical models of the AB and the debate over the validity of cross-modal ABs are discussed.     

Avoiding death or engaging life as accounts of meaning and culture: comment on Pyszczynski et al. (2004)

Terror management theory emphasizes that self-esteem consists of a sense of meaning and significance, which serves mainly to defend against death awareness. The current authors counter that people's search for meaning and significance cannot be wholly reduced to defensive processes because it also reflects intrinsic developmental processes. Sociometer theory similarly offers a mainly defensive account of self-esteem, and its exclusive focus on belongingness versus exclusion ill equips it to deal with the multiple needs underlying self-esteem. The current authors suggest that self-esteem resulting from defenses against anxiety (whether about death or exclusion) is akin to contingent self-esteem, whereas true self-esteem is based in ongoing satisfaction of needs for competence, autonomy, and relatedness.