Ideals, central tendency, and frequency of instantiation as determinants of graded structure in categories

Three possible determinants of graded structure (typicality) were observed in common taxonomic categories and goal-derived categories: (1) an exemplar's similarity to ideals associated with goals its category serves; (2) an exemplar's similarity to the central tendency of its category (family resemblance); and (3) an exemplar's frequency of instantiation (people's subjective estimates of how often it is encountered as a category member). Experiment 1 found that central tendency did not predict graded structure in goal-derived categories, although it did predict graded structure in common taxonomic categories. Ideals and frequency of instantiation predicted graded structure in both category types to sizeable and equal extents. A fourth possible determinant--familiarity--did not predict typicality in either common taxonomic or goal-derived categories. Experiment 2 demonstrated that both central tendency and ideals causally determine graded structure, and work showing that frequency causally determines graded structure is discussed. Experiment 2 also demonstrated that the determinants of a particular category's graded structure can change with context. Whereas ideals may determine a category's graded structure in one context, central tendency may determine a different graded structure in another. It is proposed that graded structures do not reflect invariant structures associated with categories but instead reflect people's dynamic ability to construct concepts.     

Stimulus generalization, context change, and forgetting

Forgetting is often attributed to retrieval failure caused by background contextual cues changing over time. However, generalization between stimuli may increase over time and make them increasingly interchangeable. If this effect occurs with contextual cues, it might cancel any effect of a changing context. The authors review the evidence and suggest a resolution of this paradox. Although generalization gradients can change over time, the effect is not always strong. Increased responding to nontarget stimuli is not often shown, and few studies have demonstrated such changes with contextual cues in a way that rules out other interpretations. Even this example of forgetting may be caused by retrieval failure. The physical contexts manipulated in learning and memory experiments themselves occur within a superordinate temporal context and can thus be forgotten with no inherent challenge to a context-change account of forgetting.     

Context change and retention interval can have additive, rather than interactive, effects after taste aversion extinction

Spontaneous forgetting is often attributed to retrieval failure caused by natural changes in the background context that occur over time. However, some investigators have argued that the context-change account of forgetting is paradoxical, because context-change effects themselves decrease over time. To resolve the paradox, we have suggested that organisms may merely forget the physical context as the temporal context in which it is embedded changes; this explanation accepts a fundamental similarity between time and physical context. The present experiment tested an implication of this analysis by examining the interaction between retention interval and context change in rats after a taste aversion was conditioned and then extinguished. Importantly, subjects tested at the longer (24-day) retention interval received reminder exposure to the physical contexts before testing. Under these conditions, retention interval and context change both caused relapse of the extinguished aversion (spontaneous recovery and renewal, respectively), and the strongest overall relapse was observed when the two treatments were combined. Such additivity (rather than interactivity) is consistent with a context-change account of forgetting and sets the stage for resolution of the context-forgetting paradox.     

Plato and the Love of Individuals

A perennial problem in the philosophy of love has centred around what it is to love persons qua persons. Plato has usually been interpreted as believing that when we love we are attaching ourselves to qualities that inhere in the objects of our love and that these qualities transcend the objects. Vlastos has argued, along with Nussbaum, Price and many others that such an account tells against a true love of persons as unique and irreplaceable individuals. I argue that Plato's account of love as presented in the Lysis and Symposium is not so easily rejected. My concern is both to show that Plato can meet the objections and that his theory can still offer helpful insights into the understanding of love in our own lives. In particular I will identify two manners of loving persons; one which is context and individual specific, and another which might be termed metaphysical, thereby preserving aspects of the Platonic ascent of love. I will further argue that the two aspects are often non–controversially linked, and that such linking helps explain something of the mysterious nature of love.     

Explaining retrieval-induced forgetting: A change in mental context between the study and restudy practice phases is not sufficient to cause forgetting

Retrieving information can impair the subsequent recall of related information. Such retrieval-induced forgetting is often attributed to inhibitory mechanisms, but Jonker, MacLeod, and Seli (2013) recently proposed an alternative account. In their view, the study and retrieval-practice phases constitute two disparate contexts, and impairment of unpractised members from practised categories is attributable to their being absent from the retrieval-practice context, which is where, according to Jonker et al., participants preferentially search at the time of final test. In evidence of this account, Jonker et al. showed that even restudy practice—which is assumed by the inhibitory account to be insufficient to cause forgetting (i.e., retrieval-specificity)—can cause forgetting when a mental context change is inserted between study and restudy. The present research sought to replicate this finding while also testing the possibility that a far mental context change would cause more forgetting than a near mental context change. In Experiment 1, participants described a vacation inside the United States (near) or outside the United States (far). In Experiments 2 and 3, participants described the layout of their own home (near) or their parents’ home (far). In contrast to the predictions of the context account, however, but consistent with the predictions of the inhibitory account, none of the restudy-plus-context-change conditions resulted in significant forgetting.     

You were always on my mind: The importance of “significant others” in the attenuation of retrieval‐induced forgetting in Japan

Research on memory has demonstrated that remembering material can cause forgetting of related information, which is known as retrieval‐induced forgetting (RIF). Macrae and Roseveare identified “self” as one of the boundary conditions of this effect in the Western cultural context, showing that RIF was eliminated when material was encoded to be related to the self (known as self‐referential effect), but not to significant others. In this study, we predicted and found that significant others could be another boundary condition in Japanese cultural contexts in which self and agency are more interdependent or conjoint; RIF was observed neither under best‐friend‐related encoding nor under family‐related encoding in Japan. The effect of significant others is found uniquely in Japanese cultural contexts, suggesting that the cultural model of self has significant power in the spontaneous system of memory.     

Direct remembering,mediated remembering,and atypical forgetting functions

Atypical forgetting functions have been demonstrated in several recent studies of delayed matching to sample, in which experimental conditions are altered partway through the retention interval. The forgetting functions are atypical in that accuracy or discriminability is not always a negatively accelerated monotonic function of increasing retention interval duration, but may increase at later times in the retention interval. Atypical forgetting functions reflect changes in levels of discrimination. A switch from a lower level to a higher level of discrimination, or vice versa, can occur at any time in the retention interval. The behavioral theories of remembering proposed by Nevin, Davison, Odum, and Shahan (2007), and White and Brown (2014), offer quantitative predictions of forgetting functions that differ in intercept or slope. Both theories are able to account for atypical forgetting functions, by assuming time‐independent changes in the mediating effect of attending to sample and comparison stimuli (in Nevin et al.'s model) or in the direct effect of the context of reinforcement of the conditional discrimination (in White & Brown's model). Despite differences in their main assumptions, the theories have an edge over any theory that assumes that forgetting is time‐dependent.     

Forgetting curves: implications for connectionist models

Forgetting in long-term memory, as measured in a recall or a recognition test, is faster for items encoded more recently than for items encoded earlier. Data on forgetting curves fit a power function well. In contrast, many connectionist models predict either exponential decay or completely flat forgetting curves. This paper suggests a connectionist model to account for power-function forgetting curves by using bounded weights and by generating the learning rates from a monotonically decreasing function. The bounded weights introduce exponential forgetting in each weight and a power-function forgetting results when weights with different learning rates are averaged. It is argued that these assumptions are biologically reasonable. Therefore power-function forgetting curves are a property that may be expected from biological networks. The model has an analytic solution, which is a good approximation of a power function displaced one lag in time. This function fits better than any of the 105 suggested two-parameter forgetting-curve functions when tested on the most precise recognition memory data set collected by. Unlike the power-function normally used, the suggested function is defined at lag zero. Several functions for generating learning rates with a finite integral yield power-function forgetting curves; however, the type of function influences the rate of forgetting. It is shown that power-function forgetting curves cannot be accounted for by variability in performance between subjects because it requires a distribution of performance that is not found in empirical data. An extension of the model accounts for intersecting forgetting curves found in massed and spaced repetitions. The model can also be extended to account for a faster forgetting rate in item recognition (IR) compared to associative recognition in short but not long retention intervals.     

The costs and benefits of testing text materials

Tests have been shown to improve the later recall of tested information, a result known as the testing effect. Tests, however, can also impair the later recall of related information, an effect known as retrieval-induced forgetting. Although retrieval-induced forgetting has been demonstrated using a wide variety of materials, recent work suggests that learning information in the context of a coherent text passage may afford protection from retrieval-induced forgetting. In four experiments we explored the conditions under which retrieval-induced forgetting does and does not occur with such materials. We found that two factors-the coherence of the to-be-learned material and the competitiveness of retrieval practice-are important in determining whether retrieval-induced forgetting does or does not occur. Furthermore, even if retrieval-induced forgetting does occur, having the opportunity to restudy the forgotten information can prevent that forgetting from persisting. Taken together, these findings provide greater understanding of the costs and benefits of testing text materials, with possible implications for the optimisation of testing as a tool for learning in educational contexts.     

The costs and benefits of testing text materials

Tests have been shown to improve the later recall of tested information, a result known as the testing effect. Tests, however, can also impair the later recall of related information, an effect known as retrieval-induced forgetting. Although retrieval-induced forgetting has been demonstrated using a wide variety of materials, recent work suggests that learning information in the context of a coherent text passage may afford protection from retrieval-induced forgetting. In four experiments we explored the conditions under which retrieval-induced forgetting does and does not occur with such materials. We found that two factors—the coherence of the to-be-learned material and the competitiveness of retrieval practice—are important in determining whether retrieval-induced forgetting does or does not occur. Furthermore, even if retrieval-induced forgetting does occur, having the opportunity to restudy the forgotten information can prevent that forgetting from persisting. Taken together, these findings provide greater understanding of the costs and benefits of testing text materials, with possible implications for the optimisation of testing as a tool for learning in educational contexts.     

Are we aware of our ability to forget? Metacognitive predictions of directed forgetting

It is often important to accurately predict not only what information we will later remember, but also what information we are likely to forget. The present research examined these abilities in the context of item-method directed forgetting, to determine whether people are aware of their strategic control of remembering and forgetting, as well as what cues are used when making metacognitive judgments. Participants studied words, each of which was followed by a cue to remember (R) or forget (F) the word for an upcoming test, and also made predictions of how likely they would be to later recall each word. When asked to recall all of the words, regardless of cue, both recall and predicted recall were fairly sensitive to the R or F instructions, despite some overconfidence. A similar and stronger pattern was found when words were assigned positive or negative point values as cues to remember or forget. These findings suggest that item-based cues to remember or forget information can be successfully utilized when making metacognitive judgments, and that people are fairly aware of the control they have over both remembering and forgetting information.     

The effect of different distractions on remembering delayed intentions

In safety-critical domains, frequently intentions need to be delayed until an ongoing task is completed. Research using the delay-execute paradigm showed that interruptions during the delay cause forgetting. However, staff members often handle an initial distraction not by interrupting the ongoing task but by acknowledging the distraction or multitasking. In Experiments 1a and 1b, we observed that, compared to a no distraction condition, multitasking significantly decreased remembering of intentions and interrupting decreased remembering even further. In Experiment 2, interruptions with context change reduced remembering of intentions compared to uninterrupted delays, and at the same time, interruptions without context change improved memory performance compared to uninterrupted delays. However, improved memory performance resulted in decreased interrupting task performance. Theoretically, the results support the contextual cueing mechanism of delay-execute tasks. Considering safety-critical domains, multitasking, interruptions and context changes can contribute to forgetting of tasks.     

The unconscious transference effect: Are innocent bystanders ever misidentified?

Unconscious transference refers to an eyewitness's misidentification of an innocent bystander for a criminal perpetrator because of the witness's exposure to the bystander in another context. In a series of five field studies involving 330 retail store clerks and 340 students, five retention intervals from 2 hours to 2 weeks, seven bystander-perpetrator intervals from 2 minutes to 2 weeks, three line-up types, two levels of line-up similarity, four different bystanders and four different targets, with one exception no evidence was obtained that could be interpreted to demonstrate the phenomenon of unconscious transference. That is, the resultsr repeatedly failed to reveal more misidentifications of an innocent bystander by witnesses who had been previously exposed to the bystander than by control evewitnesses who had not. To the contrary, the prior observation of the bystander often served to reduce the frequency of misidentification. In the final experiment the kind of misidentification error referred to as unconscious transference did occur, but only within a particular combination of bystander-perpetrator similarity and line-up construction: a combination that, in conjunction with the kind of event used, seems unlikely in real-world settings. Nevertheless, the inclusion of a familiar face in the line-ups often altered witnesses' choices in such a way that choosing someone was more likely when the lineup included a familiar face than when it did not. Finally, in contrast to the current explanations of unconscious transference, it is argued that it may not be a sense of familiarity with the bystander that is the basis of misidentifications; rather, it may also include incorrect inferences about the likelihood that the bystander might be the perpetrator.     

Filled pauses and gestures: It's not coincidence

Though filled pauses and gestures frequently accompany speech, their function is not well understood. We suggest that it may be helpful in furthering our knowledge of these phenomena to examine their relationship to each other. To this end, we carried out two studies examining whether they tend to occur together, or to occur at separate times. Both faculty colloquium speakers and undergraduate subjects used filled pauses less frequently when they were gesturing than when they were not gesturing. This effect held for 30 out of 31 subjects. We suggest that detailed theories may be premature, but speculate that gestures may be an indication that the speech production apparatus has completed its search for the next word, phrase or idea and is ready to continue.     

Context-dependent impairment of recollection in list-method directed forgetting

In list-method directed forgetting, people's ability to forget one of the sets of learned material is examined. Research shows that memory for to-be-forgotten items is impaired when assessed by a recall test and by recognition tests reliant on recollective processes. Retrieval inhibition and context-change mechanisms have been proposed to account for the directed forgetting effects and both of them account for the results obtained with recognition tests. However, the context change account makes a specific prediction that recollection is impaired by directed forgetting only if it makes use of contextual associations. In the present study, directed forgetting was examined with two types of recollection-based tasks making use of different types of associations, namely a list discrimination task utilising contextual associations and an associative recognition task utilising interitem associations. Consistent with the context change account, the costs of directed forgetting were observed in a list discrimination task and were not observed in an associative recognition task. The results indicate that impairment in recollection due to directed forgetting is not general and provide converging evidence to support the context-change account.     

How to be an Anti-Skeptic and a NonContextualist

Contextualists often argue from examples where it seems true to say in one context that a person knows something but not true to say that in another context where skeptical hypotheses have been introduced. The skeptical hypotheses can be moderate, simply mentioning what might be the case or raising questions about what a person is certain of, or radical, where scenarios about demon worlds, brains in vats, The Matrix, etc., are introduced. I argue that the introduction of these skeptical hypotheses leads people to fallaciously infer that it is no longer true to say that the relevant person knows. I believe that that is a better explanation of the so-called intuition that the person does not know than the contextualists who claim that raising these skeptical hypotheses changes the standards that determine when it is true to say S knows that P. At the end I raise the possibility that contextualists might defend their view on pragmatic rather than skeptical grounds by arguing that the standards of evidence rise when more is at stake in a practical sense.     

Metacognition influences item-method directed forgetting

In 4 experiments, we examined whether metacognitive beliefs about item memorability influence item-method directed forgetting. In Experiment 1, participants studied loud and quiet items, which were subsequently cued as to-be-remembered (TBR) or to-be-forgotten (TBF). Typically, the volume of stimuli does not influence recall, although loud items are judged as more memorable than quiet items (Rhodes & Castel, 2009). In contrast, we found a recall advantage for loud items in directed forgetting, although this was observed for TBR items but not TBF items. The loud item advantage disappeared in Experiment 2, when we eliminated all TBF trials and instead inserted additional trials during which participants could engage in extra rehearsal of earlier presented items. In Experiments 3 and 4, a recall advantage for loud items was observed again when items were assigned a mixture of positive and negative values, but it did not emerge when items were assigned graded positive values. Overall, the results showed that the recall advantage for loud items emerges only in response to the need to forget some items. We propose 2 mechanisms to account for these results-either participants select to rehearse loud items as a controlled strategy that allows them to forget some items, or they have an unconscious preference for loud items that emerges only in response to the need to forget. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Grounding and Necessity

Abstract

The elucidations and regimentations of grounding offered in the literature standardly take it to be a necessary connection. In particular, authors often assert, or at least assume, that if some facts ground another fact, then the obtaining of the former necessitates the latter; and moreover, that grounding is an internal relation, in the sense of being necessitated by the existence of the relata. In this article, I challenge the necessitarian orthodoxy about grounding by offering two prima facie counterexamples. First, some physical facts may ground a certain phenomenal fact without necessitating it; and they may co-exist with the latter without grounding it. Second, some instantiations of categorical properties may ground the instantiation of a dispositional one without necessitating it; and they may co-exist without grounding it. After arguing that these may be genuine counterexamples, I ask whether there are modal constraints on grounding that are not threatened by them. I propose two: that grounding supervenes on what facts there are, and that every grounded fact supervenes on what grounds there are. Finally, I attempt to provide a rigorous formulation of the latter supervenience claim and discuss some technical questions that arise if we allow descending grounding chains of transfinite length.     

Wiping out memories: New support for a mental context change account of directed forgetting

Costs and benefits of directed forgetting are observed when a between-list instruction to forget List 1 impairs List 1 recall while enhancing List 2 recall. These effects are often ascribed to intentional inhibition of List 1. Contrary to this inhibition account, we found that a forget instruction did not produce costs unless an explicit instruction to concentrate on List 2 was used (Experiment 1). Alternatively, costs may be ascribed to a shift in mental context between encoding and retrieval. Consistent with this mental context-change account, an unexpected task (wiping the computer screen and one's hands) produced costs comparable to a forget instruction, as did as a brief chat between lists (Experiment 2). A number-search task between lists produced neither costs nor benefits (Experiment 3), suggesting that mere distraction is insufficient for inducing mental context change. Our findings support the claim that mental context change underlies both intentional and unintentional forgetting.