One,two, or three memories? A problem-solving approach to memory for performed acts

To test three theories of memory for performed acts, four sets of experiments were conducted. Two of the theories, the rehearsal obstruction theory and the multi-code representation theory, posit separate laws for recall of performed acts. The third, a problem-solving theory, attempts to explain act memory as well as memory for visually and verbally presented information within a unified conceptual framework. One set of experiments failed to demonstrate level-of-processing effects with free recall of performed tasks, thus providing evidence in support of the theories assuming distinct laws. The three other sets of experiments, which examined serial recall of performed acts, the effect of specified encoding instructions, and the role of contextual frames in free recall of acts, all gave results in support of the monistic problem-solving interpretation.     

“Make things as simple as possible, but no simpler.” A rejoinder to Scruggs and Mastropieri

Scruggs and Mastropieri (Behaviour Research and Therapy, 32, 879–883, 1994) take issue with criticisms of their PND (Percent of Nonoverlapping Data) statistic that we offered in our recent article (Allison & German, Behaviour Research and Therapy, 31, 621–631, 1993), which advocated a regressionbased method for obtaining effect sizes in single-subject studies. They contend that their PND approach has several advantages over our approach because: (1) they believe that, unlike ours, it can take advantage of the small number of observations that are typically available in single-case studies; (2) it is simple to compute; (3) it frees researchers from traditional regression assumptions of normality, homogeneity of variance, and independence of observations and residuals; and (4) it correlates with visual judgements made by experts. As we shall argue, these claims are built upon very questionable assumptions and they are very difficult to substantiate. In addition, we show that the expected value of the PND is so strongly related to sample size as to be rendered meaningless.     

The role of hyperventilation in panic disorder: a response to Ley (1991)

Ley (Behaviour Research and Therapy, 29, 301–304, 1991) provided a reinterpretation of experimental findings on the efficacy of breathing retraining plus cognitive restructuring in reducing the symptomatology of patients with panic disorder with agoraphobia which were presented in a 1989 article in this journal. On the basis of his reinterpretation, they concluded that our findings supported the central role of hyperventilation in panic attacks. Ley's arguments are discussed and we conclude that his reinterpretation provides new arguments against a hyperventilation theory of panic. Furthermore, recent evidence from empirical studies does not support a central role for hyperventilation in panic attacks.     

A preliminary study of distinctive features in problem solving

The abstract logical structure of family relationship problems, such as, “What relationship to a man is his mother's father?” was described in terms of a “distinctive-feature-transition count (dft)”, where the answer to the problem was characterized in terms of the distinctive features of descendancy, co-linearity, and sex. On average, it proved possible to predict the difficulty of such problems from such a count; thus tending to support the idea of a relational rather than an associative memory structure.     

Contextual assimilation and its effect on the division of attention between nonverbal signals

Subjects performed a recognition task in which a low or a high frequency signal was presented simultaneously with a dim or a bright intensity one. The independent variable was the degree of association between the signals on the two dimensions. Unknown to the subjects four levels were tested in separate conditions, 1.0, 0.8, 0.5 and 0.2. Increasing the positive association improved overall sensitivity as measured by d' on both dimensions, but left contingent sensitivity unchanged. Changing the association did not affect overall bias, as measured by Beta. However, holding context constant by analysis produced significant differences between individual measures of contingent bias in the direction of assimilation, for example “low” responses tended to accompany dim signals and “dim” responses. The differences were unaffected by the changes in association. The results are interpreted as favouring models of contextual assimilation which assume that biasing at some level of processing depends upon the mutually contingent interaction of discrete events rather than on memory and expectation of the relative frequency of conjoint events. Further support for this conclusion comes from previous studies which indicate that assimilation occurs with separate responses but not with unitary ones. The implications of the findings for research on the division of attention are discussed, particularly the need to control variability in measured bias to establish a true change in the allocation of attention. Two generalized models of contextual assimilation are proposed, one based on “object” and the other on “lexical” assimilation. The possible application of these models to synaesthesia is considered.     

Information relevance, working memory, and the consideration of alternatives

People routinely focus on one hypothesis and avoid consideration of alternative hypotheses on problems requiring decisions between possible states of the world--for example, on the “pseudodiagnosticity” task (Doherty, Mynatt, Tweney, & Schiavo, 1979). In order to account for behaviour on such “inference” problems, it is proposed that people can hold in working memory, and operate upon, but one alternative at a time, and that they have a bias to test the hypothesis they think true. In addition to being an ex post facto explanation of data selection in inference tasks, this conceptualization predicts that there are situations in which people will consider alternatives. These are:

1. “action” problems, where the alternatives are possible courses of action;

2. “inference” problems, in which evidence favours an alternative hypothesis.

Experiment 1 tested the first prediction. Subjects were given action or inference problems, each with two alternatives and two items of data relevant to each alternative. They received probabilistic information about the relation between one datum and one alternative and picked one value from among the other three possible pairs of such relations. Two findings emerged; (1) a strong tendency to select information about only one alternative with inferences; and (2) a strong tendency, compared to inferences, to select information about both alternatives with actions.

Experiment 2 tested the second prediction. It was predicted that data suggesting that one alternative was incorrect would lead many subjects to consider, and select information about, the other alternative. For actions, it was predicted that this manipulation would have no effect. Again the data were as predicted.     

In defence of iconic memory

According to a model of visual information-processing which originated with Sperling (1960), and which currently enjoys wide acceptance, the contents of brief alphanumeric displays are initially held in a high-capacity fast-decay visual-information store (“iconic memory”). Some of these items are subsequently transferred to a more durable form of storage; the remaining non-transferred items are lost. Observers can select which items are to be transferred on the basis of physical characteristics of the items (such as colour, location, size, shape or brightness).

This model has recently been attacked by Holding (1970, 1971, 1972, 1973), sometimes by claiming that iconic memory does not exist, and at other times by claiming that transfer from iconic memory cannot be selectively controlled by the observer. We argue in this paper that Holding's criticisms are incorrect, and that, even if they were correct, the experiment we report would not be open to objections he has raised concerning previous studies of iconic memory. Despite this, evidence fully supporting the orthodox model was obtained, and we therefore conclude that this model remains tenable.     

Discontinuity in the enumeration of sequentially presented auditory and visual stimuli

The seeking of discontinuity in enumeration was recently renewed because Cowan [Cowan, N. (2001). The magical number 4 in short-term memory: A reconsideration of mental storage capacity. Behavioral and Brain Sciences, 24, 87–185; Cowan, N. (2005). Working memory capacity. Hove: Psychology Press] suggested that it allows evaluating the limit of the focus of attention, currently estimated at four items. A strong argument in favour of a general constraint of the cognitive system is that similar discontinuities should be observed in modalities different from the classic simultaneous presentation of visual objects. Recently, data were provided on tactile stimuli, but the authors diverged in their conclusion about the existence of such discontinuity [Gallace, A., Tan, H. Z., & Spence, C. (2006). Numerosity judgments for tactile stimuli distributed over the body surface. Perception, 35(2), 247–266; Riggs, K. J., Ferrand, L., Lancelin, D., Fryziel, L., Dumur, G., & Simpson, A. (2006). Subitizing in tactile perception. Psychological Science, 17(4), 271–272]. Following a similar rationale, our study aimed at evaluating discontinuity in the enumeration of auditory and visual stimuli presented sequentially. The clear and similar discontinuity observed in error rates, response times and given responses for both modalities favours the general capacity limit view, but also questions the size of this capacity, because the discontinuity occurred here at size 2. However, the masking of stimuli in sensory memory could not be entirely discarded.     

Simultaneous vs. sequential requests in resource dilemmas with incomplete information

We consider a class of resource dilemmas of the following form: members of groups of size n are asked to share a common resource pool whose exact size, x, is not known. Rather, x is sampled randomly from a probability distribution which is common knowledge. Each group member j (j = 1,…,n) requests r_j from the resource pool. Requests are made either simultaneously or sequentially. If (r₁+r₂+…+r_n) x all members are granted their requests; otherwise, group members get nothing.

For each protocol of play we present two alternative models - a game theoretical equilibrium solution and a psychological model incorporating the notion of focal points. We then report the results of two experiments designed to compare the two models under the two protocols of play.     

A Dynamical Systems Approach to Skill Acquisition

This paper argues that the answer to the question, what has to be learned, needs to be established before the question, how is it learned, can be meaningfully addressed. Based on this conviction, some of the limitations of current and past research on skill acquisition are discussed. Motivated by the dynamical systems approach, the question of “what has to be learned” was tackled by setting up a non-linear mathematical model of the task (i.e. learning to make sideways movements on a ski apparatus). On the basis of this model, the phase lag between movements of the platform of the apparatus and the actions of the subject was isolated as an ensemble variable reflecting the timing of the subject in relation to the dynamics of the apparatus. This variable was subsequently used to study “how” the task was learned in a discovery learning experiment, in which predictions stemming from the model were tested and confirmed. Overall, these findings provided support for the hypothesis, formulated by Bernstein (1967), that one of the important effects of practice is learning to make use of reactive forces, thereby reducing the need for active muscular forces.

In addition, the data from a previous learning experiment on the ski apparatus—the results of which had been equivocal—were reconsidered. The use of phase lag as a dependent variable provided a resolution of those findings.

On the basis of the confirmatory testing of predictions stemming from the model and the clarification of findings from a previous experiment, it is argued that the dynamical systems approach put forward here provides a powerful method for pursuing issues in skill acquisition. Suggestions are made as to how this approach can be used to systematically pursue the questions that arise as a natural outcome of the experimental evidence presented here.     

Putting color back where it belongs

I disagree with Ross about the location of colors: They are in the brain, not in the external world. It is difficult to deny that there are colors in our conscious visual experience, and if we take the causal theory of perception seriously, we cannot identify these colors with the beginning of the causal chain in perception (external objects in the distal stimulus field), but we must search for them at the end of the causal chain (in the brain). Several lines of compelling evidence from cognitive neuroscience (e.g., synesthesia, dreaming, and achromatopsia) demonstrate unambiguously that color is in the brain. Furthermore, it seems that Ross has failed to consider one substantial version of subjectivism in his article. This monistic approach to color and consciousness appears to be the least implausible alternative when we try to understand what colors are and where they reside.     

The effects of self-focused rumination on global negative self-judgements in depression

Previous research in dysphoric participants has found that compared with distraction, rumination inductions are associated with increased levels of cognitive distortions and overgeneral autobiographical memories. Watkins and Teasdale ((2001) Journal of Abnormal Psychology, 110, 353–357) investigated which component of rumination was responsible for this effect in overgeneral memory, and found two distinct modes of ruminative self-focus, with analytical, evaluative self-focus maintaining overgeneral memory, whereas self-focus low in analytical thinking reduced overgeneral memory. The present study compared the effects of these two distinct forms of self-focused rumination with another measure of overgeneral thinking—global negative self-judgements. Thirty depressed participants and thirty never-depressed participants were randomly allocated to ‘analytic’ (high analysis) or ‘experiential’ (low analysis) self-focused manipulations. As predicted, in depressed participants, the analytical self-focus condition increased ratings of the self as worthless and incompetent pre- to post-manipulation, whereas the experiential self-focus condition resulted in no significant change in such judgements. The results are consistent with the hypothesis that an analytical mode of self-focused rumination may be particularly maladaptive in depression.     

How does acoustic similarity influence short-term memory?

This study attempts to discover why items which are similar in sound are hard to recall in a short-term memory situation. The input, storage, and retrieval stages of the memory system are examined separately. Experiments I, II and III use a modification of the Peterson and Peterson technique to plot short-term forgetting curves for sequences of acoustically similar and control words. If acoustically similar sequences are stored less efficiently, they should be forgotten more rapidly. All three experiments show a parallel rate of forgetting for acoustically similar and control sequences, suggesting that the acoustic similarity effect does not occur during storage. Two input hypotheses are then examined, one involving a simple sensory trace, the other an overloading of a system which must both discriminate and memorize at the same time. Both predict that short-term memory for spoken word sequences should deteriorate when the level of background noise is increased. Subjects performed both a listening test and a memory test in which they attempted to recall sequences of five words. Noise impaired performance on the listening test but had no significant effect on retention, thus supporting neither of the input hypotheses. The final experiments studied two retrieval hypotheses. The first of these, Wickelgren's phonemic-associative hypotheses attributes the acoustic similarity effect to inter-item associations. It predicts that, when sequences comprising a mixture of similar and dissimilar items are recalled, errors should follow acoustically similar items. The second hypothesis attributes the effect to the overloading of retrieval cues which consequently do not discriminate adequately among available responses. It predicts maximum error rate on, not following, similar items. Two experiments were performed, one involving recall of visually presented letter sequences, the other of auditorily presented word sequences. Both showed a marked tendency for errors to coincide with acoustically similar items, as the second hypothesis would predict. It is suggested that the acoustic similarity effect occurs at retrieval and is due to the overloading of retrieval cues.     

Acoustic similarity and interference in short-term recognition memory: Some results of a decision-theory analysis

The following three studies of single-probe recognition memory set out to show the effect on the signal-detectability measures of d' and β (Tanner and Swets, 1954) of variations in the acoustic similarity of interfering material, which may either precede or follow the item to be remembered (proactive or retroactive interference --PI or RI). The first experiment studies a situation employed by Wickelgren (1966a), who reported that acoustically similar RI substantially reduced d'. It is shown that this effect could have been due to biases in Wickelgren's original designs, and that when a bias-free design is used, the fall in d' is only of borderline significance.

To investigate this problem further, a design was evolved in which two items were presented for memorizing, which varied in acoustic similarity to each other, and (after a distracting task) a probe was presented with one of three questions: Was this the first item of the pair? Was it the second? or, Did it occur in either position? In the first case, recognition-memory with RI of varying acoustic similarity was being studied, and as in the first experiment, it was found that similarity slightly reduced d'. With the second question, PI effects were being studied, and here negligible differences were found. With the third type of question, a “location-free” test, no effects of similarity were found. The last result rules out Posner's (1967) “acid-bath” explanation of similarity effects in interference: an explanation in terms of “differentiation” (or “filtering”) was also invalidated by the results of a third experiment, in which the same effects were found even though similarity varied only between stimulus items and interference, and not between these and the probe. Wickelgren's (1966b) associative model appears to have least difficulty in accommodating these results, though even this needs certain ad hoc assumptions to be able to do so.     

Impairments in inhibition or cognitive control in psychological disorders

Contributions to this special issue of Applied & Preventive Psychology richly elucidate connections between a variety of psychological disorders and performance in a number of tasks that are used to reason about inhibitory deficits. This commentary calls attention to the different uses of the concept of inhibition – vernacular, neural, operational, and theoretical – and suggests that the term cognitive control avoids claims about dampened memory representations that are difficult to support. Central findings from the reviews are summarized; evidence concerning suppression-induced forgetting is featured and directions to foster application are discussed.     

Implementation of a computer-based regression discrepancy model: A survey of Montana school psychologists

In 1986 Montana adopted a computer-based regression discrepancy model as a best practice for learning disability identification. State school psychologists were surveyed to investigate the model's implementation and differences between routine users and nonusers of the model. Of the respondents (N = 83), 89% reported use of the model, and 62% used the model on a regular basis. Compared with regular use, nonuse of the model was related to less agreement with regression model assumptions (p < .001), lower perception of the model's value (p < .001), greater difficulty in locating input data (p < .001), reading less documentation (p < .01), less improvement in identification skills (p < .01), and working within a larger school district (p < .01). Survey implications for acceptance of best practice procedures and computer-based regression models are discussed.     

Annotations of research and clinical perspectives on cluttering since 1964

In 1964, Deso Weiss published his landmark text Cluttering, after much persuasion by Charles Van Riper to put his thoughts in writing regarding this enigmatic speech and language disorder (Van Riper, personal communication, 1992). To our knowledge, Weiss's book was the only book in English devoted entirely to cluttering. Nearly 30 years later, a second text entitled Cluttering: A Clinical Perspective was published (Myers & St. Louis, 1992). The following annotations summarize nearly all that has been written on cluttering since Weiss's classic publication in 1964.     

Oliver Bloodstein: reflections on a career. Interview by Mark Onslow

Oliver Bloodstein arrived at the University of Iowa in 1941 to study under Wendell Johnson. There he began an influential career that included a seminal documentation of the development of stuttering, the development of the continuity hypothesis and the anticipatory struggle hypothesis, and the writing of five editions of the influential text “A Handbook on Stuttering.” In this interview Dr. Bloodstein reflects on his remarkable and inspiring career, which continues today with his involvement in the preparation of a sixth edition of this text.

Educational objectives: The reader will; (1) describe the contribution to the field of stuttering made by Dr. Bloodstein; (2) discuss the career influences that led to his achievements; (3) know Dr. Bloodstein's current views on the cause of stuttering; and (4) identify the locations at which he worked during his career.     

The effect of cue-familiarity, cue-distinctiveness, and retention interval on prospective remembering

Five experiments investigated the effects of cue familiarity, cue distinctiveness, and retention interval on prospective remembering. Results showed that (1) performance in a prospective memory task is facilitated when the cue is unfamiliar and/or distinctive; and (2) it is impaired by 3-minutes' delay between the instructions and the task (Experiment 1). A beneficial effect of distinctiveness was also found when perceptual rather than semantic distinctiveness was tested (Experiment 2). Experiments 3 and 4 ruled out the hypotheses that “unfulfilled expectancy” of an event (i.e. non-appearance of the cue during training) (Experiment 3), or some sort of “habituation” in the target context (Experiment 4), may have caused the low performance observed in the delayed conditions. Finally, results from Experiment 5 showed that delay negatively affected prospective remembering when it was filled with either a demanding interpolated activity (practice in a STM task) or an undemanding motoric activity (repetitive hands movements). Unfilled delay and an undemanding verbal activity (counting) were found not to affect prospective memory. Implications for the mechanisms underlying prospective remembering are discussed.