Recollection can be weak and familiarity can be strong

The remember-know procedure is widely used to investigate recollection and familiarity in recognition memory, but almost all of the results obtained with that procedure can be readily accommodated by a unidimensional model based on signal-detection theory. The unidimensional model holds that remember judgments reflect strong memories (associated with high confidence, high accuracy, and fast reaction times), whereas know judgments reflect weaker memories (associated with lower confidence, lower accuracy, and slower reaction times). Although this is invariably true on average, a new 2-dimensional account (the continuous dual-process model) suggests that remember judgments made with low confidence should be associated with lower old-new accuracy but higher source accuracy than know judgments made with high confidence. We tested this prediction--and found evidence to support it--using a modified remember-know procedure in which participants were first asked to indicate a degree of recollection-based or familiarity-based confidence for each word presented on a recognition test and were then asked to recollect the color (red or blue) and screen location (top or bottom) associated with the word at study. For familiarity-based decisions, old-new accuracy increased with old-new confidence, but source accuracy did not (suggesting that stronger old-new memory was supported by higher degrees of familiarity). For recollection-based decisions, both old-new accuracy and source accuracy increased with old-new confidence (suggesting that stronger old-new memory was supported by higher degrees of recollection). These findings suggest that recollection and familiarity are continuous processes and that participants can indicate which process mainly contributed to their recognition decisions.     

The effect of testing procedure on remember-know judgments

Remember-know (R-K) judgments are commonly used to assess conscious recollection of the study episode during recognition. We varied whether participants judged items as R, K, or new (one-step) or first made an old-new judgment and then made the R-K judgment (two-step). The one-step group had a higher R hit rate and K false alarm rate than did the two-step group. In addition, the K responses of the one-step group did not reliably discriminate between old and new items. When a “guess” response category was available, both groups were able to discriminate old and new items using the K response; however, K responses remained more accurate in the two-step condition. R responses appeared to be relatively immune to the effects of testing procedure when the guess category was provided. This suggests that, under some conditions, the R label can reliably indicate a distinct form of recognition memory, suggesting that allowing participants to use a guess response may help them to confine their R-K judgments to confidently recognized items. When participants are not given the option of making a guess response, they may use the R-K distinction to indicate the trace strength of the memory.     

The effects of temporal delay and orientation on haptic object recognition

We examined the effects of interstimulus interval (ISI) and orientation changes on the haptic recognition of novel objects, using a sequential shape-matching task. The stimuli consisted of 36 wedge-shaped plastic objects that varied along two shape dimensions (hole/bump and dip/ridge). Two objects were presented at either the same orientation or a different orientation, separated by either a short (3-sec) ISI or a long (15-sec) ISI. In separate conditions, ISI was blocked or randomly intermixed. Participants ignored orientation changes and matched on shape alone. Although performance was better in the mixed condition, there were no other differences between conditions. There was no decline in performance at the long ISI. There were similar, marginally significant benefits to same-orientation matching for short and long ISIs. The results suggest that the perceptual object representations activated from haptic inputs are both stable, being maintained for at least 15 sec, and orientation sensitive.     

Sum-difference theory of remembering and knowing: a two-dimensional signal-detection model

In the remember-know paradigm for studying recognition memory, participants distinguish items whose presentations are episodically remembered from those that are merely familiar. A one-dimensional model postulates that remember responses are just high-confidence old judgments, but a meta-analysis of 373 experiments shows that the receiver operating characteristic (ROC) curves predicted by this model have the wrong slope. According to the new sum-difference Theory of remembering and knowing (STREAK), old items differ from new ones in both global and specific memory strength: The old-new judgment is based on a weighted sum of these dimensions, and the remember- know judgment is based on a weighted difference. STREAK accounts for the form of several novel kinds of ROC curves and for existing remember-know and item-recognition data.     

Memory awareness disruptions in amnestic mild cognitive impairment: comparison of multiple awareness types for verbal and visuospatial material

Successful memory is normally accompanied by explicit awareness of retrieval and confidence in the accuracy of the retrieval product. Prior findings suggest that these features of metamemory can be dissociated from retrieval accuracy in Amnestic Mild Cognitive Impairment (aMCI). However, the literature on this question contains variable and conflicting results, likely because of differences in experimental conditions. We sought to systematically evaluate memory awareness disruptions in aMCI using multiple measures and stimulus formats within the same individuals. Memory awareness was tested with global predictions and postdictions, judgments of learning, confidence level ratings, and modified feeling-of-knowing ratings in tasks of visuospatial and verbal memory. These tests were administered to 14 individuals with aMCI and 15 healthy, age-matched controls. Memory awareness accuracy was calculated as the correspondence between subjective judgments and memory performance.Individuals with aMCI demonstrated impaired global and trial-level retrospective task awareness for visuospatial and verbal stimuli. Additionally, modified feeling-of-knowing awareness was impaired selectively for verbal stimuli. Statistical effect sizes for global awareness impairments were comparable to impairments in several objective neuropsychological memory assessments.Memory awareness (metamemory) disruptions in aMCI were most evident for a subset of subjective judgment types and task input modalities. These findings advance understanding of the nature of memory impairments in aMCI and support the utility of incorporating memory awareness testing to better characterize memory integrity in older adults.     

False recognition occurs more frequently during source identification than during old-new recognition

A number of recent reports have investigated false memories using variants of the Deese-Roediger-McDermott (DRM) paradigm. Because these false memories have been difficult to eliminate, this study investigated whether false recognition could be reduced by incorporating source-monitoring criteria into decision processes. Making claims about the manner in which items were learned should require more careful scrutiny of memories, and therefore false recognition should be minimized with source instructions as compared with old-new recognition instructions. In 3 experiments that varied the combination of sources, false recognition was increased rather than reduced by applying source-monitoring processes. The theoretical implications of these counterintuitive results are discussed in terms of the old-new detection component of source judgments.     

The detection model of recognition using know and remember judgments

The signal detection model forknow andremember recognition judgments was tested in two experiments. In Experiment 1, two predictions of the model were tested: (1) that measures of memory sensitivity,A′, are equivalent in value when based on either the recognition (know or remember) criterion or on the remember criterion; and (2) that there is a positive correlation between recognition bias and the proportion of know judgments that are hits, but no correlation between recognition bias and proportion of remember hits (Donaldson, 1996). Both predictions were supported by the data. In Experiment 2, the context of test items was manipulated to make it more or less similar to learning context. The detection model requires that memory sensitivity be the same for both recognition and remember judgments, regardless of test context. Alternatively, if remember judgments reflect only the retrieval of episodic information from memory, the two measures of memory sensitivity should become more disparate in value as learning and test context are made more similar. Memory sensitivity was generally the same in value for recognition and remember criteria but different across context conditions, thus supporting the detection model. The nature of the memory continuum used in detection theory is also discussed.     

Measuring unconscious knowledge: distinguishing structural knowledge and judgment knowledge

This paper investigates the dissociation between conscious and unconscious knowledge in an implicit learning paradigm. Two experiments employing the artificial grammar learning task explored the acquisition of unconscious and conscious knowledge of structure (structural knowledge). Structural knowledge was contrasted to knowledge of whether an item has that structure (judgment knowledge). For both structural and judgment knowledge, conscious awareness was assessed using subjective measures. It was found that unconscious structural knowledge could lead to both conscious and unconscious judgment knowledge. When structural knowledge was unconscious, there was no tendency for judgment knowledge to become more conscious over time. Furthermore, conscious rather than unconscious structural knowledge produced more consistent errors in judgments, was facilitated by instructions to search for rules, and after such instructions was harmed by a secondary task. The dissociations validate the use of these subjective measures of conscious awareness.     

“Remembering” emotional words is based on response bias,not recollection

Recent studies have demonstrated that emotional stimuli result in a higher proportion of recognized items that are “remembered” (e.g., Kensinger & Corkin, 2003; Ochsner, 2000), leading to greater estimates of recollection by the dual-process model (Yonelinas, 1994). This result suggests that recognition judgments to emotional stimuli depend on a recollection process. We challenge this conclusion with receiver operating characteristic (ROC) curve data from two experiments. In both experiments, subjects studied neutral and emotional words. During the recognition test, subjects made old-new confidence ratings as well as remember-know judgments. Four models of remember-know judgments were fit to individual subjects’ data: two versions of a one-dimensional signaldetection-based model (Donaldson, 1996; Wixted & Stretch, 2004), the dual-process model (Yonelinas, 1994), and the two-dimensional signal-detection-based model known as STREAK (Rotello, Macmillan, & Reeder, 2004). Consistent with the literature, we found that emotion increases subjective reports of “remembering.” However, our ROC analyses and modeling work reveal that the effect is due to response bias differences rather than sensitivity change or use of a high-threshold recollection process.     

Positive and negative remember judgments and ROCs in the plurals paradigm: Evidence for alternative decision strategies

Using old-new ratings and remember-know judgments we explored the plurals paradigm, in which studied words must be distinguished from plurality-changed lures. The paradigm allowed us to investigate negative remembering—that is, the remembering of a plural-altered study item; capacity for this judgment was found to be poorer than or equivalent to the conventional positive remembering. A response-bias manipulation affected positive but not negative remembering. The ratings were used to construct ROC curves and test the prediction of the most common dual-process theory of recognition memory (Yonelinas, 2001) that the amount of recollection can be independently estimated from ROC curves and from remember judgments. By fitting the individual data with pure signal detection theory (SDT) models and dual-process models that combined SDT and high-threshold components (HTSDT), we identified two types of subjects. For those who were better described by HTSDT, the predicted convergence of remember-know and ROC measures was observed. For those who were better described by SDT, the ROC intercept could not predict the remember rate. The data are consistent with the idea that all subjects rely on the same representation but base their decisions on different partitions of a decision space.     

Duration judgment and the segmentation of experience

Two experiments tested an interval segmentation explanation of duration judgment. In Experiment 1, a 170-sec time interval was filled with 27 unrelated words and three high-priority events (HPEs). These HPEs were clustered at the beginning of the interval (unsegmented condition) or distributed throughout the interval (segmented condition). Both recognition and recall of list information were measured, in addition to duration estimates. While no differences in memory performance were found, duration estimates were greater in the the segmented condition. Experiment 2 also tested the effects of interval segmentation but used 36 words and eight HPEs, a longer clock duration, and also measured the remembered number of events (RNE) in the interval. As in Experiment 1, the segmented condition produced longer duration estimates in the absence of memory performance and RNE differences. A segmentation hypothesis seems a better explanation of these results than previously proposed storage size or amount-of-processing models of duration judgment.     

Context effects in recognition memory: The frequency attribute

The first experiment determined whether frequency context would affect recognition memory decisions and frequency judgments. In the high-frequency context condition, 5 words were presented at study six times each prior to the section of the list containing the target items. In the low- frequency context condition, 30 words were presented at study one time each prior to the targets. The items tested were the same in the two conditions and were presented one, two, or three times each. Recognition performance and the judged frequency of target items presented once at study was higher in the high-frequency context condition than in the low-frequency context condition, but the opposite was true for items presented three times at study. The results of three subsequent recognition memory experiments suggested that encoding processes were critically involved.     

ROC curves and confidence judgements in recognition memory

Most models of recognition memory rely on a strength/familiarity-based signal detection account that assumes that the processes giving rise to a confidence judgment are the same as those giving rise to an old-new decision. Confidence is assumed to be scaled directly from the perceived familiarity of a probe. This assumption was tested in 2 experiments that examine the shape of confidence-based z receiver operating characteristic (zROC) curves under different levels of response bias induced by changing stimulus probabilities (Experiment 1) and payoffs (Experiment 2). Changes in the shape of the zROC curves with bias indicate that confidence is not scaled directly from perceived familiarity or likelihood. A model of information accumulation in recognition memory is proposed that can account for the observed effects.     

Test-induced priming of false memories

Of interest was whether prior testing of related words primes false memories in the Deese/Roediger-McDermott (DRM) paradigm. After studying lists of related words, subjects made old-new judgments about zero, three, or six related items before being tested on critical nonpresented lures. When the recognition test was self-paced, prior testing of list items led to faster false recognition judgments, but did not increase the rate of false alarms to lures from studied lists. Critically, this pattern changed when decision making at test was speeded. When forced to respond quickly—presumably precluding the use of monitoring processes—clear test-induced priming effects were observed in the rate of false memories. The results are consistent with an activation-monitoring explanation of false memories and support that retrieving veridical memories can be a source of memory error.     

编码意识对注意促进效应的影响——基于R/K范式的研究

注意促进效应指学习阶段采用目标探测性质的二级任务,不仅不会降低同时呈现的背景信息的编码加工,反而会促进其记忆。为进一步探究对背景信息的编码意识是否会影响该效应,本研究设置了有意与无意两种编码条件,并引入“记得/知道”判断进一步将再认区分为回想和熟悉性。结果表明,无意编码下也会产生ABE,但不同的编码条件下,目标探测所促进的背景信息的编码加工存在差异。有意编码条件下,目标探测促进的更多是对背景信息的精细加工,而无意编码条件下,目标探测促进的更多是对背景信息的知觉加工。     

Social desirability response bias as one source of the discrepancy between subjective weights and regression weights

This study of the judgment process investigated whether social desirability response bias is more closely associated with directly weighted subjective weights than less directly assessed regression weights. Graduating college students indicated their preferences for 11 job characteristics in four different tasks: (a) a statistical weighting task completed honestly, (b) a statistical weighting task completed to “look good” to a recruiter, (c) a subjective weighting task completed honestly, and (d) a subjective weighting task completed to “look good” to a recruiter. Predicted judgments were calculated from the weights obtained in each condition. Pearson correlation coefficients using these predicted judgments were computed between conditions; the relationship between the honest and positive impression predicted judgments derived from subjective weights was significantly greater than the relationship between honest and positive impression predicted judgments derived from regression weights for 19 of 23 participants. It was concluded that social desirability response bias was more closely related to subjective weights than to regression Weights.     

Visual awareness judgments are sensitive to accuracy feedback in stimulus discrimination tasks

In this study we tested the hypothesis that perceptual awareness judgments are sensitive to accuracy feedback about the previous action. We used a perceptual discrimination task in which participants reported their stimulus awareness. We created two conditions: No-feedback and Feedback (discrimination accuracy feedback was provided at the end of each trial). The results showed that visual awareness judgments are related to the accuracy of current and previous responses. Participants reported lower stimulus awareness for incorrectly versus correctly discriminated stimuli in both conditions; they also reported lower stimulus awareness in trials preceded by incorrect discrimination responses, compared to trials preceded by correct discrimination responses. This difference was significantly stronger in the Feedback condition, in which we also observed post-error slowing for PAS ratings. We discuss the relation between visual awareness and the effects of performance monitoring and interpret the results in the context of current theories of consciousness.     

The role of control processes and structural constraints in models of memory and social judgment

Six experiments examining a recent model of memory and social judgment are reported. In particular, the theoretical concept of a Work Space is examined in terms of both its structural properties and a variety of control processes that govern its operation. In Experiment 1, subjects were given information about a stimulus person and told that they would later be asked to recall it as well as possible. The length of the actual delay before recall and the length of the anticipated delay were factorially varied. Under short delay conditions, subjects anticipating a short delay recalled more of the information than those anticipating a long delay. The reverse was true under actual long delay conditions. Other results suggest that the anticipated length of the delay has an effect on processes related to both encoding and storage/retrieval. Experiments 2 and 3 demonstrate that, relative to no delay conditions, a long actual delay or a long anticipated delay produces polarization in social judgments. Both of these results are predicted by the model. Experiments 4–6 examine the effect of interpolated cognitive activity on memory and social judgment. As predicted by the model, relatively complicated cognitive activity leads to lower levels of recall and a greater polarization of judgments than less complicated intervening cognitive activity. It is argued that all of these results can be accounted for by the concept of a Work Space as a temporary repository devoted to the current information processing activities of the subject. It is thought that such a concept must be kept theoretically distinct from long-term memory. Implications of the results for models of memory and social judgment are discussed.     

Multiple fixed-interval schedules: transient contrast and temporal inhibition

Pigeons were exposed to four cycles per session of a multiple schedule in which each cycle involved twelve 60-sec fixed intervals followed by four 180-sec intervals [(12 FI 60-sec)(4 FI 180-sec) schedule]. Post-reinforcement pauses were shorter during the first few short intervals of each cycle than during later short intervals, and increased over the four long intervals of each cycle (positive and negative transient contrast). A (12 FI 15-sec)(4 FI 45-sec) schedule showed similar results. These two schedules differed in some other respects indicating effects of absolute FI duration on stimulus control. Differences in contrast properties between both these procedures and multiple variable-interval schedules were related to the pause-producing property of reinforcement on FI (temporal inhibition). Behavior under two other multiple fixed-interval schedules—(2 FI 360-sec)(1 FI 720-sec) and (3 FI 360-sec)(1 FI 720-sec)—differed in certain respects from both the (12 FI x-sec)(4 FI 3x-sec) schedules. These differences may be related to differences in the number of successive fixed intervals within a component (run length).