Latent mnemonic strengths are latent: A comment on Mickes, Wixted, and Wais (2007)

Mickes, Wixted, and Wais (2007) proposed a simple test of latent strength variability in recognition memory. They asked participants to rate their confidence using either a 20-point or a 99-point strength scale and plotted distributions of the resulting ratings. They found 25% more variability in ratings for studied than for new items, which they interpreted as providing evidence that latent mnemonic strength distributions are 25% more variable for studied than for new items. We show here that this conclusion is critically dependent on assumptions—so much so that these assumptions determine the conclusions. In fact, opposite conclusions, such that study does not affect the variability of latent strength, may be reached by making different but equally plausible assumptions. Because all measurements of mnemonic strength variability are critically dependent on untestable assumptions, all are arbitrary. Hence, there is no principled method for assessing the relative variability of latent mnemonic strength distributions.     

Learning-forgetting independence, unidimensional memory models, and feature models: comment on Bogartz (1990)

In his recent articles, Bogartz offered a definition of what it means for forgetting rate to be independent of degree of original learning. He showed that, given this definition, independence is confirmed by extant data. Bogartz also criticized Loftus's (1985b) proposed method for testing independence. In this commentary, we counter Bogartz's criticisms and then offer two observations. First, we show that Loftus's horizontal-parallelism test distinguishes between two interesting class of memory models: unidimensional models wherein the memory system's state can be specified by a single number and multidimensional models wherein at least two numbers are required to specify the memory system's state. Independence by Loftus's definition is implied by a unidimensional model. Bogartz's definition, in contrast, is consistent with either model. Second, to better understand the constraints on memory mechanisms dictated by the mathematics of the models under consideration, we develop a simple but general feature model of learning and forgetting. We demonstrate what constraints must be placed on this model to make learning and forgetting rate independent by Loftus's and by Bogartz's definitions.     

Conundrums in a theory of disturbed dreaming: comment on Levin and Nielsen (2007)

Levin and Nielsen (2007) presented a review of research emphasizing dreams whose content is distressing. With some broad conclusions about factors important in the understanding of distressing dreams as a springboard, the authors offered potential explanatory mechanisms for distressing dreams that range from brain structures to personality variables, drawing heavily on findings about posttraumatic stress disorder. Though a reasonable case is made for elements of the argument, implications from one perspective are not always considered in making the argument for others, issues that follow logically from certain assertions are not discussed, and certain assumptions appear unjustified. Definitional or phenomenological presentations are not always consistent, making it difficult to determine the real nature of the variables being offered and to get a clear sense of the boundaries of the model.     

Questioning the goal-switching account of the AB: comment on Ferlazzo et al. (2007)

Identification of the second of two targets (T2) is impaired when presented less than about 500?ms after the first (T1; Attentional Blink: AB). Although the AB is known to be remarkably robust across many manipulations, [Ferlazzo, F., Lucido, S., Di Nocera, F., Fagioli, S., &; Sdoia, S. (2007). Switching between goals mediates the attentional blink effect. Experimental Psychology, 54, 89–98; Ferlazzo, F., Faglioli, S., Sdoia, S., &; Di Nocera, F. (2008). Goal-completion processes affect the attentional blink. European Journal of Cognitive Psychology, 20, 697–710] found it to be substantially attenuated when the observers were set to accomplish a single goal (e.g. reporting the sum of the T1 and T2 digits) instead of a dual goal (reporting T1 and T2 separately). The larger AB obtained with the dual-goal set was ascribed to the attentional switch necessitated by the goal-switch between T1 and T2. This conclusion is questionable on three grounds: non-equivalent scoring procedures across conditions, range of inter-target lags, and unreliability of the baseline level. These issues were addressed in the present study. Contrary to Ferlazzo et al.’s conclusions, we found no AB attenuation in the single-goal, relative to the dual-goal condition.     

Issues with the SIMPLE model: comment on Brown, Neath, and Chater (2007)

SIMPLE (G. D. A. Brown, I. Neath, & N. Chater, 2007) attempts to explain data from serial recall and free recall in the same theoretical framework. While it can fit the free-recall serial-position curves that are the cornerstone of the 2-store buffer model, it does not address 2 classic issues in short-term memory research: similarity effects and presentation-rate effects. Similarity effects in free recall led to important work on organization in free recall, whereas similarity effects in serial recall led to the phonological basis of short-term memory. Presentation-rate effects operate quite differently in free and serial recall. The model also does not consider recall order effects or interresponse times in free recall, which may be problematic.     

Poisson signal-detection theory: Link between threshold models and the Gaussian assumption

The Gaussian model of signal detection cannot fit asymmetric data as long as the variances of the distributions are kept equal. It is therefore common practice to assume unequal variances in order to fit these data. But this assumption leads to the well-known crossover problem. The present paper provides new arguments for the abandonment of the Gaussian model with unequal variances. In its stead, this paper reevaluates multiple-parallel-threshold models. In particular, the Poisson model turns out to be very useful: it can handle data with any degree of asymmetry, giving a reasonable interpretation of the two parameters of the receiver-operating characteristic. The three-state-threshold model (Krantz, 1969) is given a new interpretation in light of the Poisson model. The slope of Poisson double-probability plots turns out to be much closer to unity than is predicted by the Gaussian approximation.     

Poisson signal-detection theory: link between threshold models and the Gaussian assumption.

The Gaussian model of signal detection cannot fit asymmetric data as long as the variances of the distributions are kept equal. It is therefore common practice to assume unequal variances in order to fit these data. But this assumption leads to the well-known crossover problem. The present paper provides new arguments for the abandonment of the Gaussian model with unequal variances. In its stead, this paper reevaluates multiple-parallel-threshold models. In particular, the Poisson model turns out to be very useful: it can handle data with any degree of asymmetry, giving a reasonable interpretation of the two parameters of the receiver-operating characteristic. The three-state-threshold model (Krantz, 1969) is given a new interpretation in light of the Poisson model. The slope of Poisson double-probability plots turns out to be much closer to unity than is predicted by the Gaussian approximation.     

CARIN theory reanalysis reanalyzed: a comment on Maguire, Devereux, Costello, and Cater (2007)

P. Maguire, B. Devereux, F. Costello, and A. Cater discussed the Gagné and Shoben (1997) CARIN theory of conceptual combination and, after presenting a sample drawn from the British National Corpus and comparing the two corpora, concluded that the Gagné and Shoben corpus is too small and unrepresentative. They then discussed the mathematical model presented by Gagné and Shoben and claimed that the model does not incorporate relational competition. In this article, the authors present critical aspects of the mathematical model not considered by Maguire et al. and show that the mathematical instantiation of CARIN presented by Gagn and Shoben is, in fact, very sensitive to the number of strong competing relations. The authors then present some new comparisons between the corpora, showing that they correspond surprisingly well.     

Decision-making models of remember-know judgments: comment on Rotello, Macmillan, and Reeder (2004)

The sum-difference theory of remembering and knowing (STREAK) provides a sophisticated account of many interactions in the remember-know (R-K) area (C. M. Rotello, N. A. Macmillan, & J. A. Reeder, 2004). It assumes 2 orthogonal strength dimensions and oblique criterion planes. Another dual-process model (J. T. Wixted & V. Stretch, 2004) with one decision axis has also been applied to R-K judgments with considerable success and provides new insights into the processes involved. An analysis of the 4 major R-K interactions can also be explained by a simpler one-dimensional signal detection theory (J. C. Dunn, 2004a). However these models do not make contact with standard work on recognition memory, so their scope is limited. To bridge this gap, a global-matching model (a theory of distributed associative memory [TODAM]) for R-K judgments is proposed. This model can produce good fits to the data, and there are established experimental manipulations with which to test it. It provides further support for the idea that R judgments are based on associative information, whereas K judgments are based on item information.     

Distinguishing among models and goals in personality science: comment on Ashton and Lee (2005)

This comment notes a misrepresentation of work by Caprara and Cervone (2000) contained in a recent contribution to this journal (Ashton & Lee, 2005 ). This occurrence is taken as an opportunity to highlight a positive development in personality science: investigators' increasing awareness of distinctions among alternative conceptual models that address qualitatively distinct scientific goals that each fall within the confines of the professional field. Copyright © 2005 John Wiley & Sons, Ltd.     

Differential susceptibility experiments: going beyond correlational evidence: comment on beyond mental health, differential susceptibility articles

Reviewing the studies on differential susceptibility presented in this section, we argue that the time is ripe to go beyond correlational designs to differential susceptibility experiments. In such experiments, randomization prevents hidden moderator effects on the environment and guarantees the independence of moderator and outcome, while the environment is manipulated and assessed in standard ways. Correlational studies generate a priori expectations about crucial moderators (e.g., temperament, biological sensitivity, and genetics). We discuss the differential susceptibility experiments available up until now and conclude that these experiments are feasible and contribute in unique ways to our conceptions of differential susceptibility.     

Filling-in models of completion: rejoinder to Kellman, Garrigan, Shipley, and Keane (2007) and Albert (2007)

There has been a growing interest in understanding the computations involved in the processes underlying visual segmentation and interpolation in conditions of occlusion. P. J. Kellman, P. Garrigan, T. F. Shipley, and B. P. Keane and M. K. Albert defended the view that identical contour interpolation mechanisms underlie modal and amodal completion. In the current rejoinder, the author provides further psychophysical evidence against this view and argues that no physiological data support the claim that modal and amodal contours are represented identically at any stage of processing. The author also shows that the illusory glass surfaces that Kellman et al. and Albert upheld as evidence against his arguments about luminance constraints in completion are explained by theoretical principles that he has previously articulated, and variants of these illusions receive no explanation within either of the models Kellman et al. and Albert propose. The author shows that the principles needed to explain these percepts embody fundamental asymmetries in the way that relative depth shapes segmentation and interpolation processes and that models of completion that lack these constraints--such as P. J. Kellman, P. Garrigan, and T. F. Shipley's and M. K. Albert's --cannot account for a host of documented completion phenomena.     

Testing mixture models of transitive preference: comment on Regenwetter, Dana, and Davis-Stober (2011)

This article contrasts 2 approaches to analyzing transitivity of preference and other behavioral properties in choice data. The approach of Regenwetter, Dana, and Davis-Stober (see record 2011-00732-003) assumes that on each choice, a decision maker samples randomly from a mixture of preference orders to determine whether A is preferred to B. In contrast, Birnbaum and Gutierrez (2007) assumed that within each block of trials, the decision maker has a true set of preferences and that random errors generate variability of response. In this latter approach, preferences are allowed to differ between people; within-person, they might differ between repetition blocks. Both approaches allow mixtures of preferences, both assume a type of independence, and both yield statistical tests. They differ with respect to the locus of independence in the data. The approaches also differ in the criterion for assessing the success of the models. Regenwetter et al. fitted only marginal choice proportions and assumed that choices are independent, which means that a mixture cannot be identified from the data. Birnbaum and Gutierrez fitted choice combinations with replications; their approach allows estimation of the probabilities in the mixture. It is suggested that researchers should separate tests of the stochastic model from the test of transitivity. Evidence testing independence and stationarity assumptions is presented. Available data appear to fit the assumption that errors are independent better than they fit the assumption that choices are independent.     

The diagnosticity of individual data for model selection: Comparing signal-detection models of recognition memory

We tested whether the unequal-variance signal-detection (UVSD) and dual-process signal-detection (DPSD) models of recognition memory mimic the behavior of each other when applied to individual data. Replicating previous results, there was no mimicry for an analysis that fit each individual, summed the goodness-of-fit values over individuals, and compared the two sums (i.e., a single model selection). However, when the models were compared separately for each individual (i.e., multiple model selections), mimicry was substantial. To quantify the diagnosticity of the individual data, we used mimicry to calculate the probability of making a model selection error for each individual. For nondiagnostic data (high model selection error), the results were compatible with equal-variance signal-detection theory. Although neither model was justified in this situation, a forced-choice between the UVSD and DPSD models favored the DPSD model for being less flexible. For diagnostic data (low model selection error), the UVSD model was selected more often.     

Source ROCs are (typically) curvilinear: comment on Yonelinas (1999)

On the basis of his assumption that recollection is a threshold process, A. P. Yonelinas (1999) predicted linear source-identification receiver operating characteristics (ROCs) and recently reported data that were consistent with this prediction. In this article, the authors present data showing curvilinear source-identification ROCs across various encoding and test conditions. On the basis of the source-monitoring framework (e.g., M. K. Johnson, S. Hashtroudi, & D. S. Lindsay, 1993), the authors argue that curvilinearity of source-identification ROCs is a result of differences in the qualitative characteristics of memories rather than simply the influence of undifferentiated familiarity as the dual-process model might suggest.     

Visual perception of force: comment on White (2012)

White (2012) proposed that kinematic features in a visual percept are matched to stored representations containing information regarding forces (based on prior haptic experience) and that information in the matched, stored representations regarding forces is then incorporated into visual perception. Although some elements of White's (2012) account appear consistent with previous findings and theories, other elements do not appear consistent with previous findings and theories or are in need of clarification. Some of the latter elements include the (a) differences between perception and impression (representation of force; relationship of force and resistance; role and necessity of stored representations and of concurrent simulation; roles of rules, cues, and heuristics), (b) characteristics of object motion and human movement (whether motion is internally generated or externally generated and whether motion is biological or nonbiological; generalization of human action and the extent to which perceived force depends upon similarity of object movement to human patterns of movement), (c) related perceptual and cognitive phenomena (representational momentum, imagery, psychophysics of force perception, perception of causality), and (d) scope and limitations of White's account (attributions of intentionality, falsifiability).     

Confusion in philosophy: A comment on Williams (1992)

Patricia Williams made a number of claims concerning the methods and practise of cladistic analysis and classification. Her argument rests upon the distinction of two kinds of hierarchy: a divisional hierarchy depicting evolutionary descent and the Linnean hierarchy describing taxonomic groups in a classification. Williams goes on to outline five problems with cladistics that lead her to the conclusion that systematists should eliminate cladism as a school of biological taxonomy and to replace it either with something that is philosophically coherent or to replace it with pure methodology, untainted by theory (Williams 1992, 151). Williams makes a number of points which she feels collectively add up to insurmountable problems for cladistics. We examine Williams' views concerning the two hierarchies and consider what cladists currently understand about the status of ancestors. We will demonstrate that Williams has seriously misunderstood many modern commentators on this subject and all of her five persistent problems are derivable from this misunderstanding.

Nelson (1989, 67).