Does Controlling for Temporal Parameters Change the Levels-of-Processing Effect in Working Memory?

The distinguishability between working memory (WM) and long-term memory has been a frequent and long-lasting source of debate in the literature. One recent method of identifying the relationship between the two systems has been to consider the influence of long-term memory effects, such as the levels-of-processing (LoP) effect, in WM. However, the few studies that have examined the LoP effect in WM have shown divergent results. This study examined the LoP effect in WM by considering a theoretically meaningful methodological aspect of the LoP span task. Specifically, we fixed the presentation duration of the processing component a priori because such fixed complex span tasks have shown differences when compared to unfixed tasks in terms of recall from WM as well as the latent structure of WM. After establishing a fixed presentation rate from a pilot study, the LoP span task presented memoranda in red or blue font that were immediately followed by two processing words that matched the memoranda in terms of font color or semantic relatedness. On presentation of the processing words, participants made deep or shallow processing decisions for each of the memoranda before a cue to recall them from WM. Participants also completed delayed recall of the memoranda. Results indicated that LoP affected delayed recall, but not immediate recall from WM. These results suggest that fixing temporal parameters of the LoP span task does not moderate the null LoP effect in WM, and further indicate that WM and long-term episodic memory are dissociable on the basis of LoP effects.     

The associations of illness perceptions and self-efficacy with psychological well-being of patients in preparation for joint replacement surgery

Patient well-being on referral to surgery likely affects their surgical experience yet few studies examine pre-surgical correlates of well-being. Guided by the Common Sense Model of Self-Regulation and Social Cognitive theory, this study examined whether illness and emotional representations, general and domain self-efficacy were associated with pre-surgical well-being. The pre-surgical assessment of a three-wave prospective study is reported. Fifty-four hip and knee replacements patients (mean age = 69.33; SD = 8.57) were recruited in the pre-surgery educational clinic at a UK general hospital. Patients completed a questionnaire-pack including the Revised Illness Perceptions Questionnaire, the General Self-Efficacy Scale, the Self-Efficacy for Rehabilitation Outcome Scale, the Falls-Efficacy Scale, and the Short Form of Psychological Well-Being Index. Multiple hierarchical regression analyses showed that above and beyond demographic and clinical characteristics, negative emotional representations were associated with lower psychological well-being while strong general self-efficacy beliefs were positively related to psychological well-being. Independent of demographic and clinical characteristics, joint replacement patients’ psychological well-being was associated with their cognitions and emotional reactions to their condition before surgery. Early interventions could potentially target these modifiable factors to improve pre-surgical well-being in this group of patients, with potential for additional post-surgical benefit.     

Effect of contextual knowledge on spatial layout extrapolation

Boundary extension (BE) refers to the tendency to remember a previously perceived scene with a greater spatial expanse. This phenomenon is described as resulting from different sources of information: external (i.e., visual) and internally driven (i.e., amodal, conceptual, and contextual) information. Although the literature has emphasized the role of top-down expectations to account for layout extrapolation, their effect has rarely been tested experimentally. In this research, we attempted to determine how visual context affects BE, as a function of scene exposure duration (long, short). To induce knowledge about visual context, the memorization phase of the camera distance paradigm was preceded by a preexposure phase, during which each of the to-be-memorized scenes was presented in a larger spatial framework. In an initial experiment, we examined the effect of contextual knowledge with presentation duration, allowing for in-depth processing of visual information during encoding (i.e., 15 s). The results indicated that participants exposed to the preexposure showed decreased BE, and displayed no directional memory error in some conditions. Because the effect of context is known to occur at an early stage of scene perception, in a second experiment we sought to determine whether the effect of a preview occurs during the first fixation on a visual scene. The results indicated that BE seems not to be modulated by this factor at very brief presentation durations. These results are discussed in light of current visual scene representation theories.     

Design of randomized controlled trials: Principles and methods applied to a treatment for early stuttering

The “gold standard” methodology for treatment efficacy research is the randomized controlled trial (RCT), which is used extensively in medical research and in other areas such as psychology. Results from a well designed and conducted RCT, which show a new treatment to be clinically and statistically superior to current standard practice, can lead to a change in clinical practice. This paper presents a tutorial on RCTs, presenting and discussing the following principles and methods: the trial protocol, choice of control treatment, eligibility criteria, random allocation, outcomes and hypotheses, sample size, subject recruitment, analysis by intention to treat, interim analysis, stopping rules, safety data monitoring/trial management, and study documentation. RCTs are a complicated and logistically involved methodology. Hence, prior to the commitment of resources to such a trial in the development of a new treatment, the safety and clinical promise of the new treatment needs to be demonstrated with preliminary studies. Such preliminary studies have been completed for the Lidcombe Program (LP) of early stuttering intervention, and an RCT of that treatment is being conducted at the time of writing. The principles and methods of RCTs are illustrated with reference to that study.

Educational objectives: The reader will understand the design principles and methods of RCTs. The reader will understand the logistics of conducting a RCT of a treatment for early stuttering.     

Cognitive processing impairments in a supra-second temporal discrimination task in rats with cerebellar lesion

The role of interpositus nuclei (IN) in timing in the sub-second range is well supported in eyeblink conditioning studies. Timing impairments shown in the seconds range in patients with intermediate cerebellar lesion, and known intermediate cerebellar cortex projection to IN raise the question of a possible involvement of IN in timing in the supra-second range as well. To address this question, we tested rats (Sprague-Dawley) given bilateral lesions of IN with Colchicine in a 2- vs. 8-s temporal discrimination task, followed by three daily sessions of a temporal bisection tests with five added intermediate non-reinforced durations. IN lesioned rats showed normal acquisition of the temporal discrimination, but a transient impairment of temporal sensitivity during the bisection tests. In addition, their response latencies suggested a different behavioral strategy from that of control animals. Our results indicate that the IN of the cerebellum may not be critically involved in temporal processing in the 2–8 s range, but may play a role in the cognitive processes that access temporal information in the mediation of choice behavior.     

Aging of the planning process: the role of executive functioning

This study tested whether the aging of executive functioning is linked to the decline in planning performance. Participants were divided into three groups: group 1 composed of 15 adults with a mean age of 22.7 years, group 2 composed of 15 adults with a mean age of 68.1 years and group 3 composed of 16 adults with a mean age of 78.75 years. Each participant took tests for shifting, inhibition, updating and processing speed. Planning was evaluated by the Tower of Hanoi task with 3 and 4 disks. Analyses of variance showed a main age effect on the many executive functioning and planning measures assessed. Analyses of regression indicated that combined processing speed and shifting accounted for 58.33% of performance on the 3-disk version, while processing speed accounted for only 36.86% of performance on the 4-disk version. These results are discussed in relation to two levels of the planning process: formulation and execution.     

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.     

Low working memory capacity impedes both efficiency and learning of number transcoding in children

This study aimed to evaluate the impact of individual differences in working memory capacity on number transcoding. A recently proposed model, ADAPT (a developmental asemantic procedural transcoding model), accounts for the development of number transcoding from verbal form to Arabic form by two mechanisms: the learning of new production rules that enlarge the range of numbers a child can transcode and the increase of the mental lexicon. The working memory capacity of 7-year-olds was evaluated along with their ability to transcode one- to four-digit numbers. As ADAPT predicts, the rate of transcoding errors increased when more production rules were required and when children had low working memory capacity, with these two factors interacting. Moreover, qualitative analysis of the errors produced by high- and low-span children showed that the latter have a developmental delay in the acquisition of the production rules.