Current theories of reading are divided between dual-route accounts, which propose that separable processes subserve word recognition for orthographically regular and irregular strings, and connectionist models, which propose a single mechanism mapping form to meaning. These theories make distinct predictions about the processing of acronyms, which can be orthographically illegal and yet familiar, as compared with the processing of pseudowords, which are regular but unfamiliar. This study examined whether acronyms are processed like pseudowords and words. Event-related potentials (ERPs) were recorded as subjects viewed familiar and unfamiliar acronyms, words, pseudowords, illegal strings, and--as the targets of the substantive behavioral task--proper names. Familiar acronyms elicited repetition effects on the N400 component, a functionally specific index of semantic activation processes; repetition effects for familiar acronyms were similar in magnitude, timing, and scalp distribution to those for words and pseudowords. The similarity of the brain response to familiar--but--illegal and unfamiliar--but--legal classes of stimuli is inconsistent with predictions of dual-route models of reading.
Many studies of simulated eyewitness situations have shown that under certain laboratory conditions, people's confidence about their identifications predicts their accuracy, but that their reported confidence can be affected by telling them that they chose the suspect. In this study, eyewitnesses (n= 134) to real crimes took part in lineups at an identification suite in the United Kingdom and were asked questions about their memory both before and after they were told whether they had identified the suspect or a filler. Before the eyewitnesses were told whether they had identified the suspect or a filler, their responses to several questions reliably differentiated between those who identified the suspect and those who identified a filler. In addition, responses to the memory questions were affected by telling the eyewitnesses whether or not they had identified the suspect. These results show that postidentification feedback affects real eyewitnesses and highlight the importance of recording meta-memory variables before an eyewitness discovers whether he or she has identified the suspect.
The penalty kick generates a variety of strong emotions in soccer (Carroll, Ebrahim, Tilling, Macleod, & Smith, 2002), and places the goalkeeper at such a disadvantage that only approximately 18% of penalty kicks are saved (Kropp & Trapp, 1999). We asked whether a goalkeeper can, by standing marginally left or right of goal center, bias a penalty taker implicitly to kick to the side with greater area, thus allowing the goalkeeper to dive in that direction to make a save. We show that the penalty taker is unlikely to be mindful that the goalkeeper is off center, but nevertheless can identify the side with greater area and will be more likely to direct the penalty kick to that side than to the other side.
Resource limitations are assessed by examining performance on concurrent tasks. Pitfalls in attributing dual-task conflicts to central attention rather than specific processing conflicts (Navon, 1984; Norman & Bobrow, 1975) are often underestimated. In this report, we identify a limitation in the interpretation of existing dual-task studies of working memory and describe a dual-task procedure that may be the first to assess concurrentretention costs fairly. Our results support claims of a central capacity (e.g., Baddeley, 2001; Cowan, 2001) and challenge evidence for certain task-specific limits. In dual-task procedures for studying working memory, two stimulus sets are presented in succession, to be retained concurrently, and memory for one or both sets is tested. Concurrentretention costs are decrements in memory performance on one set caused by the need to retain the other set concurrently. Concurrent-retention costs are larger when the two sets share many features (e.g., two spatial arrays or two verbal lists) than when they share few features (e.g., one spatial array and one verbal list; Baddeley & Hitch, 1974; Cocchini, Logie, Delia Sala, MacPherson, & Baddeley, 2002; Fougnie & Marois, 2006). Does this mean that working memory storage is largely domainspecific? Perhaps not. Although the theoretically relevant demand in dual-task studies of working memory is concurrent retention in two tasks, performance also could suffer from the inevitable overlap between retention in one task and encoding or responding in the other task. Set 2 encoding occurs in the presence of Set 1 retention, and responding to whichever set is tested first suffers from concurrent retention of the other set (which, in turn, suffers from response interference). If encoding or responding depends on the same resource as retention, dual-task conflicts are not solely due to the difficulty of concurrent retention. We sought to isolate effects of dual retention without any possible contribution of conflicts with encoding or responding, and to assess whether the effects of dual-task retention depend on intertask similarity. Because we collected only one response per trial, the overlap between responding and retention was eliminated. A more difficult problem was the overlap between Task 2 encoding and Task 1 retention. Our solution was to present four events on every trial in which two stimulus sets were included: Stimulus Set 1; Stimulus Set 2; a postcue to retain Set 1 only, Set 2 only, or both sets; and a memory test on one retained set. With this procedure, demands during encoding and responding are identical on trials with two stimulus sets when the postcue instruction is to retain a single set and when the postcue instruction is to retain both sets.
Confident witnesses are deemed more credible than unconfident ones, and accurate witnesses are deemed more credible than inaccurate ones. But are those effects independent? Two experiments show that errors in testimony damage the overall credibility of witnesses who were confident about the erroneous testimony more than that of witnesses who were not confident about it. Furthermore, after making an error, less confident witnesses may appear more credible than more confident ones. Our interpretation of these results is that people make inferences about source calibration when evaluating testimony and other social communication.
From the phonograph of the 19th century to the iPod today, music technologies have typically isolated the auditory dimension of music, filtering out nonacoustic information and transmitting what most people assume is the essence of music. Yet many esteemed performers over the past century, such as Judy Garland and B.B. King, are renowned for their dramatic use of facial expressions (Thompson, Graham, & Russo, 2005). Are such expressions merely show business, or are they integral to experiencing music? In the investigation reported here, we considered whether the facial expressions and head movements of singers communicate melodic information that can be ‘‘read’’ by viewers. Three trained vocalists were recorded singing ascending melodic intervals. Subjects saw the visual recordings (without sound) and rated the size of the intervals they imagined the performers were singing.
We investigated whether statistical practices in psychology have been changing since 1998.Early in this period, the American Psychological Association (APA) Task Force on Statistical Inference (TFSI; Wilkinson & TFSI, 1999) advocated improved statistical practices, including reporting effect sizes and confidence intervals (CIs).The APA (2001) Publication Manual included expanded advice on effect sizes and stated that CIs are ''in general, the best reporting strategy' ' (p.22).Any changes since 1998 may, of course, have had many causes other than those two sources of advice. STATISTICAL PRACTICES IN LEADING JOURNALSWe examined 10 leading international psychology journals that publish mainly empirical research; Figure 1 shows the journals.For each journal, we coded 40 empirical articles published in each of three periods: the first 40 published in 1998, the most recent 40 available for 2003-2004 when we coded in mid-2004, and the most recent 40 available for 2005-2006 around April 2006.We focused on three statistical practices central to the statistical-reform debate that we could code reliably: We noted any use of null-hypothesis significance testing (NHST), CIs, and figures with error bars.In addition, we searched for any discussion of CIs or error bars, or use of these to support interpretation.(Finch et al., 2004, found that even when CIs are reported, they are rarely interpreted.)We did not code effect sizes, but have elsewhere documented increases in some effect size reporting, for example, in the Journal of Consulting and Clinical Psychology (JCCP;Fidler et al., 2005).NHSTwas used in almost all articles (97.8, 97.7, and 96.9% in the three time periods, respectively).There was a substantial increase in figures with error bars (11.0, 24.7, and 37.8%; see Fig. 1, left panel; note that the CI around each mean difference does not include the mean of the previous time period, which indicates a statistically significant change from the previous time period, p < .05,two-tailed; or p rep > .92).The error bars were sometimes CIs (12.7, 9.5, and 13.8% of articles with figures with error bars), but more often represented standard errors (58.7, 43.1, and 46.7%) or were not labeled (33.0, 28.8, and 33.8%)-a serious omission (Cumming & Finch, 2005).The Journal of Experimental Psychology: General (JEPG; 12.5, 62.5, and 75%) showed the largest increase in figures with error bars, and every journal except Child Development, the Journal of Abnormal Psychology, and JCCP showed an increase from 1998 to 2005-2006 that was larger than the lower arm of the CI around the difference between those two times (examples for some journals are shown by the light error bars in Fig. 1, left panel).CIs were rarely reported, but their use increased somewhat (3.7, 9.2, and 10.6%; Fig. 1, right panel).The mean increase from 1998 to [2003][2004] was larger than the lower arm of the CI around the difference.The Journal of Abnormal Psychology, JCCP, and JEPG showed the largest increases, and they and Child Development and the Journal of Abnormal Child Psychology showed increases larger than the lower arm of the CI around the difference between 1998 and 2005-2006.Most CIs were reported in the text or a table (78.7, 64.2, and 71.5%), rather than as error bars in figures.Only 24.1% of articles with CIs had any interpretation of a CI, and such interpretation was often in terms of NHST, rather than width or precision (Cumming & Finch, 2005).Only 3 of the 168 articles with standard error bars in a figure included any interpretation of error bars.We examined editorials, Web sites, and instructions to authors for the 10 journals.Most offered little statistical advice, and there was little change since 1997.Exceptions were the Web site for JEPG, which since June 2004 has provided extensive statistical advice (http://web.uvic.ca/jepgen/tips.htm);editorials in
Failing to find a tumor in an x-ray scan or a gun in an airport baggage screening can have dire consequences, making it fundamentally important to elucidate the mechanisms that hinder performance in such visual searches. Recent laboratory work has indicated that low target prevalence can lead to disturbingly high miss rates in visual search. Here, however, we demonstrate that misses in low-prevalence searches can be readily abated. When targets are rarely present, observers adapt by responding more quickly, and miss rates are high. Critically, though, these misses are often due to response-execution errors, not perceptual or identification errors: Observers know a target was present, but just respond too quickly. When provided an opportunity to correct their last response, observers can catch their mistakes. Thus, low target prevalence may not be a generalizable cause of high miss rates in visual search.
To test whether distinct patterns of electrophysiological activity prior to a response can distinguish true from false memories, we analyzed intracranial electroencephalographic recordings while 52 patients undergoing treatment for epilepsy performed a verbal free-recall task. These analyses revealed that the same pattern of gamma-band (28-100 Hz) oscillatory activity that predicts successful memory formation at item encoding--increased gamma power in the hippocampus, prefrontal cortex, and left temporal lobe--reemerges at retrieval to distinguish correct from incorrect responses. The timing of these oscillatory effects suggests that self-cued memory retrieval begins in the hippocampus and then spreads to the cortex. Thus, retrieval of true, as compared with false, memories induces a distinct pattern of gamma oscillations, possibly reflecting recollection of contextual information associated with past experience.
Perceptual load has been found to be a powerful determinant of distractibility in laboratory tasks. The present study assessed how the effects of perceptual load on distractibility in the laboratory relate to individual differences in the likelihood of distractibility in daily life. Sixty-one subjects performed a response-competition task in which perceptual load was varied. As expected, individuals reporting high levels of distractibility (on the Cognitive Failures Questionnaire, an established measure of distractibility in daily life) experienced greater distractor interference than did individuals reporting low levels. The critical finding, however, was that this relationship was confined to task conditions of low perceptual load: High perceptual load reduced distractor interference for all subjects, eliminating any individual differences. These findings suggest that the level of perceptual load in a task can predict whether individual differences in distractibility will be found and that high-load modifications of daily tasks may prove useful in preventing unwanted consequences of high distractibility.