Realism in confidence judgements of performance based on implicit learning

In two experiments we employed calibration methods to investigate the realism of participants' confidence ratings of their own classification performance based on knowledge acquired after training on an artificial grammar. In Experiment 1 participants showed good realism (but overconfidence) for grammatical strings but very poor realism for non-grammatical strings. Method of training (string repetition in writing or mere exposure) did not affect the realism. Furthermore, the participants underestimated their overall performance. In Experiment 2, using a more complex grammar and controlling for two types of associative chunk-strength, participants showed good realism (but still overconfidence) for both letter and symbol strings, irrespective of grammaticality. Together, these experiments show that implicit learning can give rise to knowledge products that are associated with fairly realistic meta-knowledge. It is argued that both the zero-correlation criterion and the guessing criterion are misplaced when used to define implicit knowledge; two reasons being that confidence judgements may be affected both by implicit knowledge and by inferences.     

The conscious, the unconscious, and familiarity

This article examines the role of subjective familiarity in the implicit and explicit learning of artificial grammars. Experiment 1 found that objective measures of similarity (including fragment frequency and repetition structure) predicted ratings of familiarity, that familiarity ratings predicted grammaticality judgments, and that the extremity of familiarity ratings predicted confidence. Familiarity was further shown to predict judgments in the absence of confidence, hence contributing to above-chance guessing. Experiment 2 found that confidence developed as participants refined their knowledge of the distribution of familiarity and that differences in familiarity could be exploited prior to confidence developing. Experiment 3 found that familiarity was consciously exploited to make grammaticality judgments including those made without confidence and that familiarity could in some instances influence participants' grammaticality judgments apparently without their awareness. All 3 experiments found that knowledge distinct from familiarity was derived only under deliberate learning conditions. The results provide decisive evidence that familiarity is the essential source of knowledge in artificial grammar learning while also supporting a dual-process model of implicit and explicit learning.     

Further investigation on the mnemonic effect of gestures: Their meaning matters

Three experiments are reported that examine the nature of knowledge underlying performance in the invariant learning task. Previous research (Bright & Burton, 1994; McGeorge & Burton, 1990) has supported an account of performance based on the implicit abstraction and application of a rule pertaining to the invariant feature. In contrast, we found effects in both the digit and clock invariant tasks that are difficult to explain solely in terms of subjects acquiring the experimenters' rule. In all three experiments, manipulation of test item properties that are independent of the invariant feature led to a detriment in performance that is not predicted by an account based on the experimenters' rules. Furthermore, the use of an on-line measure of awareness (confidence ratings) provided some evidence that performance is mediated by low confidence explicit knowledge.     

The role of self‐rated ability in the accuracy of confidence judgements in eyewitness memory and general knowledge

It is argued that confidence stems in part from self‐rated ability in a domain of knowledge and that in eyewitness memory such perceptions are erroneous. Two experiments tested these hypotheses. In both experiments participants rated their relative ability in the domains of eyewitness memory and general knowledge and subsequently took tests of each, giving confidence ratings for each item attempted. In both studies, self‐rated ability predicted performance for general knowledge, but not eyewitness memory. Across participants confidence ratings were significant predictors of accuracy for general knowledge, but not for eyewitness memory. In Experiment 1 self‐rated ability was predictive of confidence ratings for both domains, although this effect was weaker in Experiment 2. The argument that the accuracy of confidence judgements in eyewitness memory is undermined by a lack of insight into relative expertise is therefore supported. Copyright © 2004 John Wiley & Sons, Ltd.     

Subjective measures of awareness and implicit cognition

In this article, we examine whether artificial grammar learning is implicit according to a subjective criterion of awareness based on confidence ratings. In four experiments, participants discriminated between grammatical and ungrammatical sequences in both the same (Experiment 1) and a novel (Experiments 2-4) vocabulary and indicated their confidence in each decision. Replicating earlier studies, confidence judgments reported on a continuous scale (50%-100%) were only weakly related to accuracy, suggesting that learning was implicit. In contrast, confidence judgments reported on a binary scale (high vs. low) revealed that confidence was related to accuracy. We show that participants are better able to place their phenomenal states on a binary scale, as compared with a continuous scale.     

The time course of implicit and explicit concept learning

The present experiment investigated the development of implicit and explicit knowledge during concept learning. According to Cleeremans and Jiménez (2002), the content of a representation can be conscious only when the representation is of a sufficiently good quality; on this theory, increasing explicit and decreasing implicit knowledge might be expected with training. The view that implicit knowledge arises from compilation of explicit knowledge makes the opposite prediction. The present research tested these possibilities using subjective measures based on confidence ratings. One group of participants was presented with blocks of category exemplars that activated prior knowledge, whereas another group was presented with blocks of categories that did not elicit any useful prior knowledge. The results showed that, irrespective of the knowledge group participants were allocated to, explicit knowledge increased over the course of learning, whereas implicit knowledge either stayed the same or decreased, consistent with Cleeremans and Jiménez's prediction.     

Toward an implicit measure of emotions: ratings of abstract images reveal distinct emotional states

Although implicit tests of positive and negative affect exist, implicit measures of distinct emotional states are scarce. Three experiments examined whether a novel implicit emotion-assessment task, the rating of emotion expressed in abstract images, would reveal distinct emotional states. In Experiment 1, participants exposed to a sadness-inducing story inferred more sadness, and less happiness, in abstract images. In Experiment 2, an anger-provoking interaction increased anger ratings. In Experiment 3, compared to neutral images, spider images increased fear ratings in spider-fearful participants but not in controls. In each experiment, the implicit task indicated elevated levels of the target emotion and did not indicate elevated levels of non-target negative emotions; the task thus differentiated among emotional states of the same valence. Correlations also supported the convergent and discriminant validity of the implicit task. Supporting the possibility that heuristic processes underlie the ratings, group differences were stronger among those who responded relatively quickly.     

Prior knowledge is more predictive of error correction than subjective confidence

Previous research has demonstrated that, when given feedback, participants are more likely to correct confidently-held errors, as compared with errors held with lower levels of confidence, a finding termed the hypercorrection effect. Accounts of hypercorrection suggest that confidence modifies attention to feedback; alternatively, hypercorrection may reflect prior domain knowledge, with confidence ratings simply correlated with this prior knowledge. In the present experiments, we attempted to adjudicate among these explanations of the hypercorrection effect. In Experiments 1a and 1b, participants answered general knowledge questions, rated their confidence, and received feedback either immediately after rating their confidence or after a delay of several minutes. Although memory for confidence judgments should have been poorer at a delay, the hypercorrection effect was equivalent for both feedback timings. Experiment 2 showed that hypercorrection remained unchanged even when the delay to feedback was increased. In addition, measures of recall for prior confidence judgments showed that memory for confidence was indeed poorer after a delay. Experiment 3 directly compared estimates of domain knowledge with confidence ratings, showing that such prior knowledge was related to error correction, whereas the unique role of confidence was small. Overall, our results suggest that prior knowledge likely plays a primary role in error correction, while confidence may play a small role or merely serve as a proxy for prior knowledge.     

Effects of divided attention and speeded responding on implicit and explicit retrieval of artificial grammar knowledge

The artificial grammar (AG) learning literature (see, e.g., Mathews et al., 1989; Reber, 1967) has relied heavily on a single measure of implicitly acquired knowledge. Recent work comparing this measure (string classification) with a more indirect measure in which participants make liking ratings of novel stimuli (e.g., Manza & Bornstein, 1995; Newell & Bright, 2001) has shown that string classification (which we argue can be thought of as an explicit, rather than an implicit, measure of memory) gives rise to more explicit knowledge of the grammatical structure in learning strings and is more resilient to changes in surface features and processing between encoding and retrieval. We report data from two experiments that extend these findings. In Experiment 1, we showed that a divided attention manipulation (at retrieval) interfered with explicit retrieval of AG knowledge but did not interfere with implicit retrieval. In Experiment 2, we showed that forcing participants to respond within a very tight deadline resulted in the same asymmetric interference pattern between the tasks. In both experiments, we also showed that the type of information being retrieved influenced whether interference was observed. The results are discussed in terms of the relatively automatic nature of implicit retrieval and also with respect to the differences between analytic and nonanalytic processing (Whittlesea & Price, 2001).     

Incidental Learning of Melodic Structure of North Indian Music

Musical knowledge is largely implicit. It is acquired without awareness of its complex rules, through interaction with a large number of samples during musical enculturation. Whereas several studies explored implicit learning of mostly abstract and less ecologically valid features of Western music, very little work has been done with respect to ecologically valid stimuli as well as non‐Western music. The present study investigated implicit learning of modal melodic features in North Indian classical music in a realistic and ecologically valid way. It employed a cross‐grammar design, using melodic materials from two modes (rāgas) that use the same scale. Findings indicated that Western participants unfamiliar with Indian music incidentally learned to identify distinctive features of each mode. Confidence ratings suggest that participants' performance was consistently correlated with confidence, indicating that they became aware of whether they were right in their responses; that is, they possessed explicit judgment knowledge. Altogether our findings show incidental learning in a realistic ecologically valid context during only a very short exposure, they provide evidence that incidental learning constitutes a powerful mechanism that plays a fundamental role in musical acquisition.     

The role of reversal frequency in learning noisy second order conditional sequences

The hallmark of implicit learning is that complex knowledge can be acquired unconsciously. The second order conditionals (SOCs) of Reed and Johnson (1994) were developed to be complex, and they are popular materials for implicit learning research. Recently, it was demonstrated that in a sequence made noisy (by combining two SOCs), shared features of the SOCs may be learned explicitly (Fu, Fu, & Dienes, 2008). What are these shared features? We hypothesized that low reversal frequency may play a significant role. We have varied reversal frequency, and discovered that reversal frequency affected response times, inclusion exclusion behavior, and recognition ratings. Not only does it appear to be important to distinguish implicit and explicit knowledge, but also to distinguish what the knowledge is of.     

Considering the Knowledge You Have: Effects on Realism in Confidence Judgements

In three experiments, the hypothesis was tested that the realism of subjects' item-specific confidence judgements of their own answers to general knowledge questions would be improved by making the subjects heed content which might be expected to lower their confidence ratings. In each experiment, all subjects answered knowledge questions and then rated their confidence in their chosen answer. Before each question, the subjects in the experimental condition assessed the extent of their knowledge in a knowledge-area encompassing the knowledge question. Experiments 1 and 2 differed only in the design of the knowledge-area assessment scale. In Experiment 3, when making knowledge-area assessments, the subjects were asked to find examples of knowledge they lacked in the knowledge-area. Both Experiments 2 and 3 showed significantly improved realism in the subjects' confidence judgements. An aggregate assessment of the total number of questions believed to be answered correctly, given by the subjects at the end of Experiments 2 and 3, showed underconfidence in the experimental condition, particularly in Experiment 3. The results support the idea that the content active in subjects' memory at the time when confidence judgements are made affects their realism. Furthermore, our results show that the realism of subjects' item-specific confidence judgements can be improved without giving feedback.     

Effects of timbre and tempo change on memory for music

We investigated the effects of different encoding tasks and of manipulations of two supposedly surface parameters of music on implicit and explicit memory for tunes. In two experiments, participants were first asked to either categorize instrument or judge familiarity of 40 unfamiliar short tunes. Subsequently, participants were asked to give explicit and implicit memory ratings for a list of 80 tunes, which included 40 previously heard. Half of the 40 previously heard tunes differed in timbre (Experiment 1) or tempo (Experiment 2) in comparison with the first exposure. A third experiment compared similarity ratings of the tunes that varied in timbre or tempo. Analysis of variance (ANOVA) results suggest first that the encoding task made no difference for either memory mode. Secondly, timbre and tempo change both impaired explicit memory, whereas tempo change additionally made implicit tune recognition worse. Results are discussed in the context of implicit memory for nonsemantic materials and the possible differences in timbre and tempo in musical representations.     

Self-Ratings of Personality: A Naturalistic Comparison of Normative, Ipsative, and Idiothetic Standards

ABSTRACT The purpose of this research is to examine some of the implicit standards that individuals may use when they rate themselves on personality dimensions Specifically, we compared ratings based on instructions that specified normative, ipsative, or idiothetic creteria with ratings obtained when subjects used their own (implicit) standards In a series of three studies, we found that each of the explicit ratings was highly similar to the implicit-standard ratings and that there were substantial individual differences in the relative similarity of each of the explicit ratings to the implicit ratings However, because the normative instructions elicited less extreme responses than any of the other instructions, there was a small but consistent tendency for them to be less similar to the ratings based on implicit standards than the ipsative or idiothetic ratings The implications of this research for personality assessment and self-evaluation are discussed     

Memory for things forgotten.

As previous research has shown, items not recalled on an initial memory task are not simply forgotten. Often, some can be recalled on a later, second task. Further, subjects can generally predict, in terms of feeling-of-knowing (FOK) ratings, which items will be subsequently recalled. Two experiments were carried out to assess both second-task performance and FOK accuracy for unrecalled items as a function of two factors, encoding manipulations (levels of processing in Experiment 1, study time in Experiment 2) and the nature of the second task (explicit or implicit cued stem completion). Results indicate that although levels of processing affected explicit second-task performance more than implicit second-task performance, it increased FOK accuracy in both types of tasks. Study time, however, affected FOK accuracy only in the explicit second task. Apparently, only when subjects were able to do some elaborative processing on the items did their FOK ratings reflect information relating to factors that drive performance on implicit tasks.     

Response selection strategies and realism of confidence judgments

Two studies were conducted to examine how response selection strategy is related to confidence ratings and to performance on general knowledge questions. In both studies subjects were asked to answer 80 general knowledge questions and to rate their confidence in the correctness of the answer selected. A pilot study, in which subjects thought aloud while answering general knowledge questions, was carried out to identify different response selection strategies. In the first study, 40 subjects were asked to indicate which of four strategies (immediate recognition, inference, intuition, or guessing) they used for selecting an answer. In Study 2, think aloud reports from 20 subjects were coded into the same four strategies. The distribution of strategies differed between the studies, but there were very similar relations among strategy, confidence, and correctness of answer in the two studies. Response selection strategy was related to correctness of answer when confidence was partialed out. More specifically, immediate recognition was associated with higher proportion correct than with the other strategies. It was also found that ratings of how difficult the knowledge questions were to fellow students of the subjects were on a much more realistic level than the confidence ratings were. It is concluded that people could improve their confidence judgments by taking into account (a) how difficult a question is to other people, and (b) the response selection strategy used for answering the question.     

RATS,We Should Have Used Clinton: Subliminal Priming in Political Campaigns

Political strategists decide daily how to market their candidates. Growing recognition of the importance of implicit processes (processes occurring outside of awareness) suggests limitations to focus groups and polling, which rely on conscious self‐report. Two experiments, inspired by national political campaigns, employed Internet‐presented subliminal primes to study evaluations of politicians. In Experiment 1, the subliminal word “RATS” increased negative ratings of an unknown politician. In Experiment 2, conducted during former California Governor Gray Davis's recall referendum, a subliminal photo of Clinton affected ratings of Davis, primarily among Independents. Results showed that subliminal stimuli can affect ratings of well‐known as well as unknown politicians. Further, subliminal studies can be conducted in a mass media outlet (the Internet) in real time and supplement voter self‐report, supporting the potential utility of implicit measures for campaign decision making.     

Implicit and explicit tests of odor memory reveal different outcomes following interference

Experiencing two odors as a mixture can later increase their perceived similarity when presented separately. Such an increase in similarity can be used as an implicit measure of how well participants remember the mixture. Three experiments tested the resistance to interference of this effect by first giving participants exposure to two 2-odor mixtures and then presenting each odor from one mixture (interfered pair) separately many times. After the latter interference phase, participants rated the similarity of the two odors in each pair. The experiments varied in terms of the number of initial exposures to the mixtures, the number of odor presentations in the interference phase, and the control conditions employed. No difference in similarity ratings for the interfered and non-interfered pair was found in any experiment. In contrast to the lack of interference with this implicit measure, an explicit measure of memory based on participants’ ratings of odor frequency revealed that they could recall to some degree that the interfered odors had been presented alone in the second phase. These results suggest that implicit memory for odor mixtures is highly resistant to interference and is consistent with a configural encoding account of this effect.     

Decomposing intuitive components in a conceptual problem solving task

Research into intuitive problem solving has shown that objective closeness of participants' hypotheses were closer to the accurate solution than their subjective ratings of closeness. After separating conceptually intuitive problem solving from the solutions of rational incremental tasks and of sudden insight tasks, we replicated this finding by using more precise measures in a conceptual problem-solving task. In a second study, we distinguished performance level, processing style, implicit knowledge and subjective feeling of closeness to the solution within the problem-solving task and examined the relationships of these different components with measures of intelligence and personality. Verbal intelligence correlated with performance level in problem solving, but not with processing style and implicit knowledge. Faith in intuition, openness to experience, and conscientiousness correlated with processing style, but not with implicit knowledge. These findings suggest that one needs to decompose processing style and intuitive components in problem solving to make predictions on effects of intelligence and personality measures.     

Meet The Simpsons: top-down effects in face learning

We examined whether prior knowledge of a person affects the visual processes involved in learning a face. In two experiments, subjects were taught to associate human faces with characters they knew (from the TV show The Simpsons) or characters they did not (novel names). In each experiment, knowledge of the character predicted performance in a recognition memory test, relying only on old/new confidence ratings. In experiment 1, we established the technique and showed that there is a face-learning advantage for known people, even when face items are counterbalanced for familiarity across the experiment. In experiment 2 we replicated the effect in a setting which discouraged subjects from attending more to known than unknown people, and eliminated any visual association between face stimuli and a character from The Simpsons. We conclude that prior knowledge about a person can enhance learning of a new face.