Showing papers in "Journal of Experimental Psychology: Learning, Memory and Cognition in 2009"

Conducting the train of thought: working memory capacity, goal neglect, and mind wandering in an executive-control task.

Abstract: On the basis of the executive-attention theory of working memory capacity (WMC; e.g., M. J. Kane, A. R. A. Conway, D. Z. Hambrick, & R. W. Engle, 2007), the authors tested the relations among WMC, mind wandering, and goal neglect in a sustained attention to response task (SART; a go/no-go task). In 3 SART versions, making conceptual versus perceptual processing demands, subjects periodically indicated their thought content when probed following rare no-go targets. SART processing demands did not affect mind-wandering rates, but mind-wandering rates varied with WMC and predicted goal-neglect errors in the task; furthermore, mind-wandering rates partially mediated the WMC–SART relation, indicating that WMC-related differences in goal neglect were due, in part, to variation in the control of conscious thought.

Affective and deliberative processes in risky choice: Age differences in risk taking in the Columbia Card Task.

Abstract: The authors investigated risk taking and underlying information use in 13- to 16- and 17- to 19-year-old adolescents and in adults in 4 experiments, using a novel dynamic risk-taking task, the Columbia Card Task (CCT). The authors investigated risk taking under differential involvement of affective versus deliberative processes with 2 versions of the CCT, constituting the most direct test of a dual-system explanation of adolescent risk taking in the literature so far. The "hot" CCT was designed to trigger more affective decision making, whereas the "cold" CCT was designed to trigger more deliberative decision making. Differential involvement of affective versus deliberative processes in the 2 CCT versions was established by self-reports and assessment of electrodermal activity. Increased adolescent risk taking, coupled with simplified information use, was found in the hot but not the cold condition. Need-for-arousal predicted risk taking only in the hot condition, whereas executive functions predicted information use in the cold condition. Results are consistent with recent dual-system explanations of risk taking as the result of competition between affective processes and deliberative cognitive-control processes, with adolescents' affective system tending to override the deliberative system in states of heightened emotional arousal.

Unsuccessful retrieval attempts enhance subsequent learning.

Abstract: Taking tests enhances learning. But what happens when one cannot answer a test question—does an unsuccessful retrieval attempt impede future learning or enhance it? The authors examined this question using materials that ensured that retrieval attempts would be unsuccessful. In Experiments 1 and 2, participants were asked fictional general-knowledge questions (e.g., “What peace treaty ended the Calumet War?”). In Experiments 3–6, participants were shown a cue word (e.g., whale) and were asked to guess a weak associate (e.g., mammal); the rare trials on which participants guessed the correct response were excluded from the analyses. In the test condition, participants attempted to answer the question before being shown the answer; in the read-only condition, the question and answer were presented together. Unsuccessful retrieval attempts enhanced learning with both types of materials. These results demonstrate that retrieval attempts enhance future learning; they also suggest that taking challenging tests—instead of avoiding errors—may be one key to effective learning.

Cue strength as a moderator of the testing effect: the benefits of elaborative retrieval.

Abstract: The current study explored the elaborative retrieval hypothesis as an explanation for the testing effect: the tendency for a memory test to enhance retention more than restudying. In particular, the retrieval process during testing may activate elaborative information related to the target response, thereby increasing the chances that activation of any of this information will facilitate later retrieval of the target. In a test of this view, participants learned cue-target pairs, which were strongly associated (e.g., Toast: Bread) or weakly associated (e.g., Basket: Bread), through either a cued recall test (Toast: _____) or a restudy opportunity (Toast: Bread). A final test requiring free recall of the targets revealed that tested items were retained better than restudied items, and although strong cues facilitated recall of tested items initially, items recalled from weak cues were retained better over time, such that this advantage was eliminated or reversed at the time of the final test. Restudied items were retained at similar rates on the final test regardless of the strength of the cue-target relationship. These results indicate that the activation of elaborative information-which would occur to a greater extent during testing than restudying--may be one mechanism that underlies the testing effect.

Should I stay or should I switch? A cost-benefit analysis of voluntary language switching in young and aging bilinguals.

Abstract: Bilinguals spontaneously switch languages in conversation even though laboratory studies reveal robust cued language switching costs. The authors investigated how voluntary-switching costs might differ when switches are voluntary. Younger (Experiments 1-2) and older (Experiment 3) Spanish-English bilinguals named pictures in 3 conditions: (a) dominant-language only, (b) nondominant-language only, and (c) using "whatever language comes to mind" (in Experiment 2, "using each language about half the time"). Most bilinguals, particularly balanced bilinguals, voluntarily mixed languages even though switching was costly. Unlike with cued switching, voluntary switching sometimes facilitated responses, switch costs were not greater for the dominant language, and age effects on language mixing and switching were limited. This suggests that the freedom to mix languages voluntarily allows unbalanced and older bilinguals to function more like balanced and younger bilinguals. Voluntary switch costs reveal an expanded role for inhibitory control in bilingual language production and imply a mandatory separation by language in bilingual lexical selection.

Strategies for revising judgment: How (and how well) people use others’ opinions.

Abstract: A basic issue in social influence is how best to change one's judgment in response to learning the opinions of others. This article examines the strategies that people use to revise their quantitative estimates on the basis of the estimates of another person. The authors note that people tend to use 2 basic strategies when revising estimates: choosing between the 2 estimates and averaging them. The authors developed the probability, accuracy, redundancy (PAR) model to examine the relative effectiveness of these two strategies across judgment environments. A surprising result was that averaging was the more effective strategy across a wide range of commonly encountered environments. The authors observed that despite this finding, people tend to favor the choosing strategy. Most participants in these studies would have achieved greater accuracy had they always averaged. The identification of intuitive strategies, along with a formal analysis of when they are accurate, provides a basis for examining how effectively people use the judgments of others. Although a portfolio of strategies that includes averaging and choosing can be highly effective, the authors argue that people are not generally well adapted to the environment in terms of strategy selection.

Bilingual lexical access in context: evidence from eye movements during reading.

Abstract: Current models of bilingualism (e.g., BIA ) posit that lexical access during reading is not languageselective. However, much of this research is based on the comprehension of words in isolation. Theauthors investigated whether nonselective access occurs for words embedded in biased sentence contexts(e.g., A. I. Schwartz & J. F. Kroll, 2006). Eye movements were recorded as French–English bilingualsread English sentences containing cognates (e.g., piano ), interlingual homographs (e.g., coin, meaningcorner in French), or matched control words. Sentences provided a low or high semantic constraint fortarget-language meanings. Both early-stage comprehension measures (e.g., first fixation duration, gazeduration, and skipping) and late-stage comprehension measures (e.g., go-past time and total reading time)showed significant cognate facilitation and interlingual homograph interference for low-constraintsentences. For high-constraint sentences, however, only early-stage comprehension measures wereconsistent with nonselective access. There was no evidence of cognate facilitation or interlingualhomograph interference for late-stage comprehension measures. Thus, nonselective bilingual lexicalaccess at early stages of comprehension is rapidly resolved in semantically biased contexts at later stagesof comprehension.Keywords: bilingualism, eye tracking, sentence processing, interlingual homographs, cognates

Complex span versus updating tasks of working memory: the gap is not that deep.

Abstract: How to best measure working memory capacity is an issue of ongoing debate. Besides established complex span tasks, which combine short-term memory demands with generally unrelated secondary tasks, there exists a set of paradigms characterized by continuous and simultaneous updating of several items in working memory, such as the n-back, memory updating, or alpha span tasks. With a latent variable analysis (N = 96) based on content-heterogeneous operationalizations of both task families, the authors found a latent correlation between a complex span factor and an updating factor that was not statistically different from unity (r = .96). Moreover, both factors predicted fluid intelligence (reasoning) equally well. The authors conclude that updating tasks measure working memory equally well as complex span tasks. Processes involved in building, maintaining, and updating arbitrary bindings may constitute the common working memory ability underlying performance on reasoning, complex span, and updating tasks.

Separable brain systems supporting cued versus self-initiated realization of delayed intentions.

Abstract: In everyday life, one can link anticipated specific cues (e.g. visiting a restaurant) with desired actions (e.g., ordering a healthy meal). Alternatively, intentions such as "I intend to eat more healthily" present the option to act when one encounters the same cue. In the first case, a specific cue triggers a specific action; in the second, one must act in a more self-initiated manner. The authors compared such scenarios using functional magnetic resonance imaging. Participants were either instructed to respond in a particular manner to target events (cued condition) or told that they would score points for such responses, without being told that they were necessary (self-initiated condition). Although conditions differed only in the wording of instructions, the self-initiated condition was associated with poorer performance and greater activity in a predominantly frontoparietal network. Responses to targets in the self-initiated and cued conditions yielded greater activity in lateral and medial Brodmann area 10, respectively. The authors suggest that these results reflect differing demands for self-initiated versus externally cued behavior following different types of instruction, in line with the distinction between goal intentions and implementation intentions proposed by P. M. Gollwitzer and colleagues.

Anticipated reward enhances offline learning during sleep.

Abstract: Sleep is known to promote the consolidation of motor memories. In everyday life, typically more than 1 isolated motor skill is acquired at a time, and this possibly gives rise to interference during consolidation. Here, it is shown that reward expectancy determines the amount of sleep-dependent memory consolidation. Subjects were trained on 2 different sequences of a finger sequence motor task before 12-hr retention intervals of either nocturnal sleep or daytime wakefulness. After training was finished, reward expectancy was varied by announcing a monetary reward for performance improvement at retesting on either the first- or second-trained sequence. Before the retest, however, subjects were informed that reward would depend not on only 1 sequence but on the average performance for both sequences. Posttraining sleep enhanced overall finger sequence performance. The sleep-dependent gain in skill was significantly greater for the sequence that was associated with monetary reward after training, regardless of whether this sequence was the first or second to be trained. After wake retention intervals, no or only minor performance gains were observed. The data show that expectancy for a reward enhances offline learning of a skill during sleep.

In Search of Decay in Verbal Short-Term Memory

Abstract: Is forgetting in the short term due to decay with the mere passage of time, interference from other memoranda, or both? Past research on short-term memory has revealed some evidence for decay and a plethora of evidence showing that short-term memory is worsened by interference. However, none of these studies has directly contrasted decay and interference in short-term memory in a task that rules out the use of rehearsal processes. In this article the authors present a series of studies using a novel paradigm to address this problem directly, by interrogating the operation of decay and interference in short-term memory without rehearsal confounds. The results of these studies indicate that short-term memories are subject to very small decay effects with the mere passage of time but that interference plays a much larger role in their degradation. The authors discuss the implications of these results for existing models of memory decay and interference.

Deficits in cross-race face learning: insights from eye movements and pupillometry.

Abstract: The own-race bias (ORB) is a well-known finding wherein people are better able to recognize and discriminate own-race faces, relative to cross-race faces. In 2 experiments, participants viewed Asian and Caucasian faces, in preparation for recognition memory tests, while their eye movements and pupil diameters were continuously monitored. In Experiment 1 (with Caucasian participants), systematic differences emerged in both measures as a function of depicted race: While encoding cross-race faces, participants made fewer (and longer) fixations, they preferentially attended to different sets of features, and their pupils were more dilated, all relative to own-race faces. Also, in both measures, a pattern emerged wherein some participants reduced their apparent encoding effort to cross-race faces over trials. In Experiment 2 (with Asian participants), the authors observed the same patterns, although the ORB favored the opposite set of faces. Taken together, the results suggest that the ORB appears during initial perceptual encoding. Relative to own-race face encoding, cross-race encoding requires greater effort, which may reduce vigilance in some participants.

Sources of bias in the Goodman-Kruskal gamma coefficient measure of association: implications for studies of metacognitive processes.

Abstract: In many cognitive, metacognitive, and perceptual tasks, measurement of performance or prediction accuracy may be influenced by response bias. Signal detection theory provides a means of assessing discrimination accuracy independent of such bias, but its application crucially depends on distributional assumptions. The Goodman-Kruskal gamma coefficient, G, has been proposed as an alternative means of measuring accuracy that is free of distributional assumptions. This measure is widely used with tasks that assess metamemory or metacognition performance. The authors demonstrate that the empirically determined value of G systematically deviates from its actual value under realistic conditions. A distribution-specific variant of G, called G-sub(c), is introduced to show why this bias arises. The findings imply that caution is needed when using G as a measure of accuracy, and alternative measures are recommended.

Recognition ROCs are curvilinear-or are they? On premature arguments against the two-high-threshold model of recognition.

Abstract: Recent reviews of recognition receiver operating characteristics (ROCs) claim that their curvilinear shape rules out threshold models of recognition. However, the shape of ROCs based on confidence ratings is not diagnostic to refute threshold models, whereas ROCs based on experimental bias manipulations are. Also, fitting predicted frequencies to actual data is a more sensitive method for model comparisons than ROC regressions. In a reanalysis of 59 published data sets, the 2-high-threshold model (2HTM) fit the data better than an unequal variance signal detection model in about half of the cases. Three recognition experiments with experimental bias manipulation were conducted that yielded linear ROCs and a better fit of the 2HTM in all cases. On the basis of actual data and a simulation, the authors argue that both models are at least equally valid as measurement tools and can perhaps be integrated theoretically.

Extremely selective attention: eye-tracking studies of the dynamic allocation of attention to stimulus features in categorization.

Abstract: Humans have an extremely flexible ability to categorize regularities in their environment, in part because of attentional systems that allow them to focus on important perceptual information. In formal theories of categorization, attention is typically modeled with weights that selectively bias the processing of stimulus features. These theories make differing predictions about the degree of flexibility with which attention can be deployed in response to stimulus properties. Results from 2 eye-tracking studies show that humans can rapidly learn to differently allocate attention to members of different categories. These results provide the first unequivocal demonstration of stimulus-responsive attention in a categorization task. Furthermore, the authors found clear temporal patterns in the shifting of attention within trials that follow from the informativeness of particular stimulus features. These data provide new insights into the attention processes involved in categorization.

Inhibition in language switching: what is inhibited when switching between languages in naming tasks?

Abstract: When people switch between languages, inhibition of currently irrelevant languages is assumed to occur. The authors examined inhibition of irrelevant languages with a cued language-switching paradigm. A cue indicated in which of 3 languages (German, English, or French) a visual stimulus was to be named. In 2 experiments, the authors found that naming latencies were increased in n-2 language repetitions (e.g., German/English/German) compared with in n-2 language nonrepetitions (e.g., French/English/German). This difference (n-2 repetition costs) indicates persisting inhibition of abandoned languages. It is important to note that n-2 language-repetition costs also occurred in conditions in which the language but not the cue (Experiment 1) or the stimulus/response set (Experiment 2) repeated from trial n-2 to trial n. These data demonstrate that inhibition is not restricted to a specific cue or stimulus/response set. Rather, the data suggest more global inhibitory processes that affect the mental representation of competing languages.

Lexical competition during second-language listening: sentence context, but not proficiency, constrains interference from the native lexicon.

Abstract: A spoken language eye-tracking methodology was used to evaluate the effects of sentence context and proficiency on parallel language activation during spoken language comprehension. Nonnative speakers with varying proficiency levels viewed visual displays while listening to French sentences (e.g., Marie va decrire la poule [Marie will describe the chicken]). Displays depicted several objects including the final noun target (chicken) and an interlingual near-homophone (e.g., pool) whose name in English is phonologically similar to the French target (poule). Listeners' eye movements reflected temporary consideration of the interlingual competitor when hearing the target noun, demonstrating cross-language lexical competition. However, competitor fixations were dramatically reduced when prior sentence information was incompatible with the competitor (e.g., Marie va nourrir... [Marie will feed...]). In contrast, interlingual competition from English did not vary according to participants' rated proficiency in French, even though proficiency reliably predicted other aspects of processing behavior, suggesting higher proficiency in the active language does not provide a significant independent source of control over interlingual competition. The results provide new insights into the nature of parallel language activation in naturalistic sentential contexts.

Bindings between stimuli and multiple response codes dominate long-lag repetition priming in speeded classification tasks.

Abstract: Repetition priming is often thought to reflect the facilitation of 1 or more processes engaged during initial and subsequent presentations of a stimulus. Priming can also reflect the formation of direct, stimulus– response (S-R) bindings, retrieval of which bypasses many of the processes engaged during the initial presentation. Using long-lag repetition priming of semantic classification of visual stimuli, the authors used task switches between study and test phases to reveal several signatures of S-R learning in Experiments 1 through 5. Indeed, the authors found surprisingly little, if any, evidence of priming that could not be attributed to S-R learning, once they considered the possibility that stimuli are simultaneously bound to multiple, different response codes. Experiments 6 and 7 provided more direct evidence for independent contributions from at least 3 levels of response representation: the action (e.g., specific finger used), the decision (e.g., yes–no), and the task-specific classification (e.g., bigger–smaller). Although S-R learning has been discussed previously in many contexts, the present results go beyond existing theories of S-R learning. Moreover, its dominant role brings into question many interpretations of priming during speeded classification tasks in terms of perceptual– conceptual processing.

Visual and Spatial Working Memory Are Not That Dissociated After All: A Time-Based Resource-Sharing Account

Abstract: Examinations of interference between visual and spatial materials in working memory have suggested domain- and process-based fractionations of visuo-spatial working memory. The present study examined the role of central time-based resource sharing in visuo-spatial working memory and assessed its role in obtained interference patterns. Visual and spatial storage were combined with both visual and spatial on-line processing components in computer-paced working memory span tasks (Experiment 1) and in a selective interference paradigm (Experiment 2). The cognitive load of the processing components was manipulated to investigate its impact on concurrent maintenance for both within-domain and betweendomain combinations of processing and storage components. In contrast to both domain- and processbased fractionations of visuo-spatial working memory, the results revealed that recall performance was determined by the cognitive load induced by the processing of items, rather than by the domain to which those items pertained. These findings are interpreted as evidence for a time-based resource-sharing mechanism in visuo-spatial working memory.

Motormouth: mere exposure depends on stimulus-specific motor simulations.

Abstract: The authors apply an embodied account to mere exposure, arguing that through the repeated exposure of a particular stimulus, motor responses specifically associated to that stimulus are repeatedly simulated, thus trained, and become increasingly fluent. This increased fluency drives preferences for repeated stimuli. This hypothesis was tested by blocking stimulus-specific motor simulations during repeated exposure. In Experiment 1, chewing gum while evaluating stimuli destroyed mere exposure effects (MEEs) for words but not for visual characters. However, concurrently kneading a ball left both MEEs unaffected. In Experiment 2, concurrently whispering an unrelated word destroyed MEEs for words but not for characters, even when implemented either exclusively during the initial presentation or during the test phase and when the first presentation involved an evaluation or a mere study of the stimuli. In Experiment 3, a double dissociation between 2 classes of stimuli was demonstrated, namely, words (oral) and tunes (vocal). A concurrent oral task (tongue movements) destroyed MEEs for words but not for tone sequences. A concurrent vocal task (humming "mm-hm") destroyed MEEs for tone sequences but not for words.

How task representations guide attention: Further evidence for the shielding function of task sets

Abstract: To pursue goal directed behavior, the cognitive system must be shielded against interference from irrelevant information. Aside from the online adjustment of cognitive control widely discussed in the literature, an additional mechanism of preventive goal shielding is suggested that circumvents irrelevant information from being processed in the first place. Participants had to react to 8 different words depicting clothing items that were presented in front of line drawings that could be either semantically related (clothes) or unrelated (animals with spatial orientation) to the target words. Participants either learned the stimulus–response (S–R) mappings by heart or used 1 task set (TS). In the S–R group, semantically related and unrelated distractors interfered with performance, whereas in the TS group, only semantically related distractors interfered, and unrelated distractors had no effect. It follows that task representations based on a general TS help to focus attention on relevant information, thereby preventing the processing of irrelevant information.

Bilingualism reduces native-language interference during novel-word learning.

Abstract: The goal of the present work was to examine the effects of bilingualism on adults' ability to resolve cross-linguistic inconsistencies in orthography-to-phonology mappings during novel-word learning. English monolinguals and English-Spanish bilinguals learned artificially constructed novel words that overlapped with English orthographically but diverged from English phonologically. Native-language orthographic information presented during learning interfered with encoding of novel words in mono- linguals but not in bilinguals. In general, bilinguals outperformed monolinguals on the word-learning task. These findings indicate that knowledge of 2 languages facilitates word learning and shields English-Spanish bilinguals from interference associated with cross-linguistic inconsistencies in letter- to-phoneme mappings.

Women match men when learning a spatial skill.

Abstract: Meta-analytic studies have concluded that although training improves spatial cognition in both sexes, the male advantage generally persists. However, because some studies run counter to this pattern, a closer examination of the anomaly is warranted. The authors investigated the acquisition of a basic skill (spatial selective attention) using a matched-pair two-wave longitudinal design. Participants were screened with the use of an attentional visual field task, with the objective of selecting and matching 10 male-female pairs, over a wide range (30% to 57% correct). Subsequently, 20 participants 17-23 years of age (selected from 43 screened) were trained for 10 hr (distributed over several sessions) by playing a first-person shooter video game. This genre is known to be highly effective in enhancing spatial skills. All 20 participants improved, with matched members of the male-female pairs achieving very similar gains, independent of starting level. This is consistent with the hypothesis that the learning trajectory of women is not inferior to that of men when acquiring a basic spatial skill. Training methods that develop basic spatial skills may be essential to achieve gender parity in both basic and complex spatial tasks.

Congruity effects between materials and processing tasks in the survival processing paradigm.

Abstract: Nairne, Thompson, and Pandeirada (2007) reported a series of experiments in which processing unrelated words in terms of their relevance to a grasslands survival scenario led to better retention relative to other semantic processing tasks. The impetus for their study was the premise that human memory systems evolved under the selection pressures of our ancestral past. In 3 experiments, we extended this functional approach to investigate the congruity effect-the common finding that people remember items better if those items are congruent with the way in which they are processed. Experiment 1 was a replication of Nairne et al.'s (2007) experiment and showed congruity effects in the survival processing paradigm. To avoid potential item-selection artifacts from randomly selected words, we manipulated congruence between words and processing condition in Experiments 2 and 3. As expected, final recall was highest when the type of processing and the materials were congruent, indicating that people remember stimuli better if the stimuli are congruent with the goals associated with their processing. However, contrary to our predictions, no survival processing advantage emerged between the 2 congruent conditions or for a list of irrelevant words. When congruity was controlled in a mixed list design, the survival processing advantage disappeared.

The link between form and meaning in American Sign Language: lexical processing effects.

Abstract: Signed languages exploit iconicity (the transparent relationship between meaning and form) to a greater extent than spoken languages. where it is largely limited to onomatopoeia. In a picture-sign matching experiment measuring reaction times, the authors examined the potential advantage of iconicity both for 1st- and 2nd-language learners of American Sign Language (ASL). The results show that native ASL signers are faster to respond when a specific property iconically represented in a sign is made salient in the corresponding picture, thus providing evidence that a closer mapping between meaning and form can aid in lexical retrieval. While late 2nd-language learners appear to use iconicity as an aid to learning sign (R. Campbell, P. Martin, & T. White, 1992), they did not show the same facilitation effect as native ASL signers, suggesting that the task tapped into more automatic language processes. Overall, the findings suggest that completely arbitrary mappings between meaning and form may not be more advantageous in language and that, rather, arbitrariness may simply be an accident of modality.

Playing chess unconsciously.

Abstract: Expertise in a certain stimulus domain enhances perceptual capabilities. In the present article, the authors investigate whether expertise improves perceptual processing to an extent that allows complex visual stimuli to bias behavior unconsciously. Expert chess players judged whether a target chess configuration entailed a checking configuration. These displays were preceded by masked prime configurations that either represented a checking or a nonchecking configuration. Chess experts, but not novice chess players, revealed a subliminal response priming effect, that is, faster responding when prime and target displays were congruent (both checking or both nonchecking) rather than incongruent. Priming generalized to displays that were not used as targets, ruling out simple repetition priming effects. Thus, chess experts were able to judge unconsciously presented chess configurations as checking or nonchecking. A 2nd experiment demonstrated that experts' priming does not occur for simpler but uncommon chess configurations. The authors conclude that long-term practice prompts the acquisition of visual memories of chess configurations with integrated form-location conjunctions. These perceptual chunks enable complex visual processing outside of conscious awareness.

Transposed-letter priming of prelexical orthographic representations.

Abstract: A prime generated by transposing two internal letters (e.g., jugde) produces strong priming of the original word (judge). In lexical decision, this transposed-letter (TL) priming effect is generally weak or absent for nonword targets; thus, it is unclear whether the origin of this effect is lexical or prelexical. The authors describe the Bayesian Reader theory of masked priming (D. Norris & S. Kinoshita, 2008), which explains why nonwords do not show priming in lexical decision but why they do in the cross-case same-different task. This analysis is followed by 3 experiments that show that priming in this task is not based on low-level perceptual similarity between the prime and target, or on phonology, to make the case that priming is based on prelexical orthographic representation. The authors then use this task to demonstrate equivalent TL priming effects for nonwords and words. The results are interpreted as the first reliable evidence based on the masked priming procedure that letter position is not coded absolutely within the prelexical, orthographic representation. The implications of the results for current letter position coding schemes are discussed.

Causal learning with local computations.

Abstract: The authors proposed and tested a psychological theory of causal structure learning based on local computations. Local computations simplify complex learning problems via cues available on individual trials to update a single causal structure hypothesis. Structural inferences from local computations make minimal demands on memory, require relatively small amounts of data, and need not respect normative prescriptions as inferences that are principled locally may violate those principles when combined. Over a series of 3 experiments, the authors found (a) systematic inferences from small amounts of data; (b) systematic inference of extraneous causal links; (c) influence of data presentation order on inferences; and (d) error reduction through pretraining. Without pretraining, a model based on local computations fitted data better than a Bayesian structural inference model. The data suggest that local computations serve as a heuristic for learning causal structure.

Exaggerated risk: Prospect theory and probability weighting in risky choice

Abstract: In 5 experiments, we studied precautionary decisions in which participants decided whether or not to buy insurance with specified cost against an undesirable event with specified probability and cost. We compared the risks taken for precautionary decisions with those taken for equivalent monetary gambles. Fitting these data to Tversky and Kahneman's (1992) prospect theory, we found that the weighting function required to model precautionary decisions differed from that required for monetary gambles. This result indicates a failure of the descriptive invariance axiom of expected utility theory. For precautionary decisions, people overweighted small, medium-sized, and moderately large probabilities-they exaggerated risks. This effect is not anticipated by prospect theory or experience-based decision research (Hertwig, Barron, Weber, & Erev, 2004). We found evidence that exaggerated risk is caused by the accessibility of events in memory: The weighting function varies as a function of the accessibility of events. This suggests that people's experiences of events leak into decisions even when risk information is explicitly provided. Our findings highlight a need to investigate how variation in decision content produces variation in preferences for risk.

Automaticity of cognitive control: goal priming in response-inhibition paradigms.

Abstract: Response inhibition is a hallmark of cognitive control. An executive system inhibits responses by activating a stop goal when a stop signal is presented. The authors asked whether the stop goal could be primed by task-irrelevant information in stop-signal and go/no-go paradigms. In Experiment 1, the task-irrelevant primes GO, ###, or STOP were presented in the go stimulus. Go performance was slower for STOP than for ### or GO. This suggests that the stop goal was primed by task-irrelevant information. In Experiment 2, STOP primed the stop goal only in conditions in which the goal was relevant to the task context. In Experiment 3, GO, ###, or STOP were presented as stop signals. Stop performance was slower for GO than for ### or STOP. These findings suggest that task goals can be primed and that response inhibition and executive control can be influenced by automatic processing.