Noise methods in pattern perception

This experiment investigated 4 methods of inducing visual noise at 7 levels of noise. Fortysix Ss were presented 4800 sets of 3 pattems, with the task of judging which of 2 noisy patterns was more similar to the prototype pattern. The noisy patterns were generated by adding, moving, deleting or both adding and deleting elements of the prototype. All possible comparisons of each noise method were made at each noise level and the results plotted. The results show that the various methods of introducing noise do not produce identical results, and that the similarity assessment is dependent on noise koel. Explanations are offered to account for the results.     

Overt expression of experimenter expectancies,interaction with subject expectancies,and performance on a psychomotor task

Subsequent to success or failure experience, 48 subjects attempted a psychomotor task in order to escape or avoid an aversive stimulus (tone). Their attempts at solving the task over 24 trials were made in the presence of subject-experimenters each of whom had expectancies instilled regarding the solution to the task. The job of the subject-experimenters was to “offer information” on every third trials as the subjects attempted to solve the task. It was hypothesized that the expectancies of the subject-experimenters would be communicated to the subjects via periodic comments, that these expectancies would differentially affect the subjects' performance on the task, and that prior experience on a similar task would differentially affect subjects' performances on the task. The results demonstrated that the expectancies instilled in the subject-experimenters were communicated and influenced the performances of subjects as predicted. It appears that consistency with respect to the expectancies communicated played a major role in producing significant effects. Prior experience failed to produce significant differences on task performance, a finding conflicting with that of D.S. Hiroto (Journal of Experimental Psychology, 1974, 102, 187–193). The results are discussed from the perspective of using the overt, explicit communication of expectancies as a means for exploring the illusive phenomenon of the experimenter expectancy effect.     

Positive and negative generation effects,hypermnesia, and total recall time

Self-generated information is typically remembered better than perceived information (the generation effect). Experimental design produces an important limiting condition for this effect: Generation enhances recall in within-subjects designs, but typically not in between-subjects designs. However, Mulligan (2001) found that the generation effect emerged over repeated recall tests in a between-subjects design, calling into question the generality of this limiting condition. Two experiments further delineated the emergent generation effect Experiment 1 demonstrated that this effect does not require multiple discrete recall tests but may emerge on a single recall test of long duration. Experiment 2 demonstrated that the negative generation effect (a reversal of the typical generation effect produced under certain conditions) is abolished by multiple recall tests. In both experiments, the generate condition produced greater hypemnesia (increased recall over tests) than did the read condition.     

Reducing the drop-out rates of at-risk high school students: the Effective Learning Program (ELP)

The purpose of the present study was to evaluate the effectiveness of the Effective Learning Program (ELP) with students who are at high risk for dropping out of high school. The intervention sought to change external control expectancies to more internal ones, improve students' skills in building relationships with peers and adults, and increase graduation rates. Thirty-eight students considered at risk for dropping out of high school received the intervention. In addition, ELP-eligible students who did not receive the ELP intervention (n = 36) and regular education students (n = 50) from the same high school were compared with the students who received the ELP. A significantly greater percentage of ELP students graduated, became more internally controlled, achieved more as shown by standardized tests, and developed greater social skills and better relationships than their ELP-eligible but nonparticipating peers. The authors suggest that researchers identify which aspects of the ELP are responsible for the improvement in retention, achievement, and personal attributes.     

Connectivity among semantic associates: an fMRI study of semantic priming

Semantic priming refers to a reduction in the reaction time to identify or make a judgment about a stimulus that has been immediately preceded by a semantically related word or picture and is thought to result from a partial overlap in the semantic associates of the two words. A semantic priming lexical decision task using spoken words was presented in event-related fMRI and behavioral paradigms. Word pairs varied in terms of semantic relatedness and the connectivity between associates. Thirteen right-handed subjects underwent fMRI imaging and 10 additional subjects were tested in a behavioral version of the semantic priming task. It was hypothesized priming would be greatest, reaction time fastest, and cortical activation reduced the most for related word pairs of high connectivity, followed by related word pairs of low connectivity, and then by unrelated word pairs. Behavioral and fMRI results confirmed these predictions. fMRI activity located primarily in bilateral posterior superior and middle temporal regions showed modulation by connectivity and relatedness. The results suggest that these regions are involved in semantic processing.     

Remembering all that and then some: Recollection of autobiographical memories after a 1-year delay

We have previously shown that repeated retrievals of remote autobiographical memories over the course of one month led to an overall increase in reported detail (Nadel, Campbell, & Ryan, 2007). The current study examined the retrieval of those same memories 1 year later in order to determine whether the level of detail remained stable or whether the memories returned to their original state. Participants reported even more details than they had recalled at least 1 year earlier, including new details that were reported for the first time. This finding was consistent across both multiple and single retrieval conditions, suggesting that the critical factor leading to the increase in recall was the passage of time. These findings provide evidence for long-term effects of repeated retrieval on memory content.     

Differential Automatic Processing Deficits in Early Stage Alzheimer's Disease

This experiment sought further support for the view that early stage Alzheimer's disease (AD) disrupts cognitive structures that cast experience into a temporal framework. Forty participants, evenly divided between normal elderly (NE) and persons diagnosed with mild AD, viewed 19 lists of 14 pictures each. Following the presentation of each list participants were asked to identify the most recently experienced picture (target) from 3 pictures. A second stimulus was a picture never previously seen; the third picture was a distracting item that had appeared in the list on either one or three occasions. The results show that whereas choice accuracy of the NE group remained largely unimpaired regardless of the delay between the target and the judgment task or the frequency of the distractor, the AD participants exhibited large and profound deficits in temporal judgments, especially when distractor frequency was greater than the more recent event. In effect, the AD group relied on how often an event occurred rather than the time of its occurrence. This finding is consistent with previous research that found AD patients deficient in forming a temporal representation of their experience.     

Parental Strategies for Knowledge of Adolescents’ Friends: Distinct from Monitoring?

Parental monitoring is defined as a set of behaviors used to gain knowledge about an adolescent’s whereabouts, friends and associates, and activities. However, can knowledge of adolescents’ whereabouts/activities, and friends all be attained through the same strategies? Or do they require their own strategies? This study used qualitative interviews with 173 parents of older adolescents from 100 families. Emergent themes described strategies by which parents gain information about their adolescents’ friends and the substance use of those friends. The strategies included direct interaction with the friend, gaining information from the teen, using second-hand sources, and making assumptions. Some of these strategies were consistent with previous research, while others raise new questions and provide interesting new directions to pursue. Primarily, additional consideration needs to be given to assessments of parental monitoring that include strategies for gaining knowledge of adolescents’ friends and their substance use.