Working memory resources are shared across sensory modalities

A common assumption in the working memory literature is that the visual and auditory modalities have separate and independent memory stores. Recent evidence on visual working memory has suggested that resources are shared between representations, and that the precision of representations sets the limit for memory performance. We tested whether memory resources are also shared across sensory modalities. Memory precision for two visual (spatial frequency and orientation) and two auditory (pitch and tone duration) features was measured separately for each feature and for all possible feature combinations. Thus, only the memory load was varied, from one to four features, while keeping the stimuli similar. In Experiment 1, two gratings and two tones—both containing two varying features—were presented simultaneously. In Experiment 2, two gratings and two tones—each containing only one varying feature—were presented sequentially. The memory precision (delayed discrimination threshold) for a single feature was close to the perceptual threshold. However, as the number of features to be remembered was increased, the discrimination thresholds increased more than twofold. Importantly, the decrease in memory precision did not depend on the modality of the other feature(s), or on whether the features were in the same or in separate objects. Hence, simultaneously storing one visual and one auditory feature had an effect on memory precision equal to those of simultaneously storing two visual or two auditory features. The results show that working memory is limited by the precision of the stored representations, and that working memory can be described as a resource pool that is shared across modalities.     

A multiprogram approach to real-time experimentation

A technique for implementing real-time experiments utilizing several separate and independent programs is discussed. The technique can be employed when the experimental procedure is divided into real-time and nonreal-time program units. These program units are executed in the most appropriate computing environment, and the resulting output is directed to a sequential file. The nonreal-time program issues commands to the real-time program by means of keywords that are inserted in the sequential file output at those points where real-time operations are required. These commands are interpreted by the real-time program which processes the sequential file. While the nonreal-time program is experiment-specific, the real-time program is independent of the particular experiment performed. The applications of this multiprogram approach to real-time experimentation are considered.     

Cognitive integration of language and memory in bilinguals: semantic representation

Understanding cognitive research on the integration of 2 languages in bilingual memory is difficult because of the different terminology, methodology, analysis, and interpretation strategies that scholars with different backgrounds bring to the research. These studies can be usefully categorized on 2 dimensions: memory for verbal experience versus linguistic knowledge, and systemwise versus pairwise issues. Experimental findings in this area converge on the conclusion that at the word meaning/conceptual level, both episodic and linguistic memory can be characterized as shared at the systems level and at least partly shared at the pairwise translation-equivalent level. Interpretation problems that stem from weak hypothesis testing structure and from covert translation can be minimized by using appropriate design and analysis techniques.     

How do I remember that I know you know that I know?

Communication is aided greatly when speakers and listeners take advantage of mutually shared knowledge (i.e., common ground). How such information is represented in memory is not well known. Using a neuropsychological-psycholinguistic approach to real-time language understanding, we investigated the ability to form and use common ground during conversation in memory-impaired participants with hippocampal amnesia. Analyses of amnesics' eye fixations as they interpreted their partner's utterances about a set of objects demonstrated successful use of common ground when the amnesics had immediate access to common-ground information, but dramatic failures when they did not. These findings indicate a clear role for declarative memory in maintenance of common-ground representations. Even when amnesics were successful, however, the eye movement record revealed subtle deficits in resolving potential ambiguity among competing intended referents; this finding suggests that declarative memory may be critical to more basic aspects of the on-line resolution of linguistic ambiguity.     

ListChecker Pro 1.2: A program designed to facilitate creating word lists using the University of South Florida word association norms

Various areas of research (e.g., memory, metamemory, visual word recognition, associative priming) rely on the careful construction of reliable word lists. ListChecker Pro 1.2 is a computer program that accesses the University of South Florida word association norms (Nelson, McEvoy, & Schreiber, 1998, 2004) to report characteristics of words (e.g., frequency, concreteness), as well as direct and indirect associative relationships (e.g., shared associates, mediators). The present article presents the input requirements, menu options, and output obtained by ListChecker Pro 1.2. In addition, a randomly selected list of words from the associative versus semantic priming literature was submitted to ListChecker Pro 1.2 to demonstrate how seemingly unrelated words can be associated. The zipped file containing the program and database can be downloaded from www .eakinmemorylab.psychology.msstate.edu.     

Fine-grained Concurrency with Separation Logic

Reasoning about concurrent programs involves representing the information that concurrent processes manipulate disjoint portions of memory. In sophisticated applications, the division of memory between processes is not static. Through operations, processes can exchange the implied ownership of memory cells. In addition, processes can also share ownership of cells in a controlled fashion as long as they perform operations that do not interfere, e.g., they can concurrently read shared cells. Thus the traditional paradigm of distributed computing based on locations is replaced by a paradigm of concurrent computing which is more tightly based on program structure. Concurrent Separation Logic with Permissions, developed by O’Hearn, Bornat et al., is able to represent sophisticated transfer of ownership and permissions between processes. We demonstrate how these ideas can be used to reason about fine-grained concurrent programs which do not employ explicit synchronization operations to control interference but cooperatively manipulate memory cells so that interference is avoided. Reasoning about such programs is challenging and appropriate logical tools are necessary to carry out the reasoning in a reliable fashion. We argue that Concurrent Separation Logic with Permissions provides such tools. We illustrate the logical techniques by presenting the proof of a concurrent garbage collector originally studied by Dijkstra et al., and extended by Lamport to handle multiple user processes.     

Aspects of programmable calculator stimulus control and data acquisition in a psychophysiology laboratory

Advantages and disadvantages of programmable calculator control of research laboratories are discussed. Comparisons are drawn with microcomputers such as the Imsai 8080. While microcomputers have greater flexibility in sampling multiple measures at multiple rates and combining timing tasks with data acquisition, calculators are easier to program for applications combining data acquisition with mathematical processing. Calculators also offer advantages to laboratories that do not have access to programming or maintenance services.     

A floppy disk operating system for the 8080 and Z80

Techniques for the design and implementation of a floppy disk operating system for the 8080A or Z80 microprocessors are described. Implementation details are illustrated through reference to SOS, a prototype Small Operating System which runs with a single IBM-format floppy drive on an 8080. Techniques for floppy disk communication, disk directory design, and system resource management are described and illustrated.     

A multiprocessor system for generating visual displays and controlling experiments

A laboratory is described that is based on an IMSAI 8080 microcomputer and an IMLAC graphics display system. Procedures for using the system are described and illustrated.     

Flexible attention allocation to visual and auditory working memory tasks: manipulating reward induces a trade-off

Prominent roles for general attention resources are posited in many models of working memory, but the manner in which these can be allocated differs between models or is not sufficiently specified. We varied the payoffs for correct responses in two temporally-overlapping recognition tasks, a visual array comparison task and a tone sequence comparison task. In the critical conditions, an increase in reward for one task corresponded to a decrease in reward for the concurrent task, but memory load remained constant. Our results show patterns of interference consistent with a trade-off between the tasks, suggesting that a shared resource can be flexibly divided, rather than only fully allotted to either of the tasks. Our findings support a role for a domain-general resource in models of working memory, and furthermore suggest that this resource is flexibly divisible.     

Animal models of source memory

Source memory is the aspect of episodic memory that encodes the origin (i.e., source) of information acquired in the past. Episodic memory (i.e., our memories for unique personal past events) typically involves source memory because those memories focus on the origin of previous events. Source memory is at work when, for example, someone tells a favorite joke to a person while avoiding retelling the joke to the friend who originally shared the joke. Importantly, source memory permits differentiation of one episodic memory from another because source memory includes features that were present when the different memories were formed. This article reviews recent efforts to develop an animal model of source memory using rats. Experiments are reviewed which suggest that source memory is dissociated from other forms of memory. The review highlights strengths and weaknesses of a number of animal models of episodic memory. Animal models of source memory may be used to probe the biological bases of memory. Moreover, these models can be combined with genetic models of Alzheimer's disease to evaluate pharmacotherapies that ultimately have the potential to improve memory.     

Using Excel to estimate parameters from observed data: An example from source memory data

We present an application, using Excel, that can solve best-fitting parameters for multinomial models. Multinomial modeling has become increasingly popular and can be used in a variety of domains, such as memory, perception, and other domains in which processes are assumed to be dissociable. We offer an application that can be used for a variety of psychological models and can be used on both PC and Macintosh platforms. We illustrate the use of our program by analyzing data from a source memory experiment.     

The effect of the order in which episodic autobiographical memories versus autobiographical knowledge are shared on feelings of closeness

Autobiographical memories (AMs) can be used to create and maintain closeness with others [Alea, N., &; Bluck, S. (2003). Why are you telling me that? A conceptual model of the social function of autobiographical memory. Memory, 11(2), 165–178]. However, the differential effects of memory specificity are not well established. Two studies with 148 participants tested whether the order in which autobiographical knowledge (AK) and specific episodic AM (EAM) are shared affects feelings of closeness. Participants read two memories hypothetically shared by each of four strangers. The strangers first shared either AK or an EAM, and then shared either AK or an EAM. Participants were randomly assigned to read either positive or negative AMs from the strangers. Findings suggest that people feel closer to those who share positive AMs in the same way they construct memories: starting with general and moving to specific.     

Getting connected: Both associative and semantic links structure semantic memory for newly learned persons

The present study examined whether semantic memory for newly learned people is structured by visual co-occurrence, shared semantics, or both. Participants were trained with pairs of simultaneously presented (i.e., co-occurring) preexperimentally unfamiliar faces, which either did or did not share additionally provided semantic information (occupation, place of living, etc.). Semantic information could also be shared between faces that did not co-occur. A subsequent priming experiment revealed faster responses for both co-occurrence/no shared semantics and no co-occurrence/shared semantics conditions, than for an unrelated condition. Strikingly, priming was strongest in the co-occurrence/shared semantics condition, suggesting additive effects of these factors. Additional analysis of event-related brain potentials yielded priming in the N400 component only for combined effects of visual co-occurrence and shared semantics, with more positive amplitudes in this than in the unrelated condition. Overall, these findings suggest that both semantic relatedness and visual co-occurrence are important when novel information is integrated into person-related semantic memory.     

When visual and verbal memories compete: Evidence of cross-domain limits in working memory

Recently, investigators have suggested that visual working memory operates in a manner unaffected by the retention of verbal material. We question that conclusion on the basis of a simple dual-task experiment designed to rule out phonological memory and to identify a more central faculty as the source of a shared limitation. With a visual working memory task in which two arrays of color squares were to be compared, performance was unaffected by concurrent recitation of a two-digit list or a known seven-digit sequence. However, visual working memory performance decreased markedly when paired with a load of seven random digits. This was not a simple tradeoff, inasmuch as errors on the visual array and high digit load tasks tended to co-occur. Working memory for digits and visual information thus are both subject to at least one type of shared limit, not just domain-specific limitations. The nature of the shared limit is discussed.     

L’entraînement de la mémoire de travail par le programme Cogmed et le TDAH

IntroductionAttention-deficit/hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder. Inattention, hyperactivity, and impulsivity are key symptoms of ADHD. It is typically associated with working memory deficits at the cognitive level. For this reason, interventions have been designed to train working memory in ADHD. Currently, Cogmed Working Memory Training program is the most commonly used and studied program in clinical practice and research. This program is proposed as an intervention for ADHD that targets working memory deficits with specific exercises through intensive training sessions.ObjectivesThe goal of this literature review is to examine the effects of the Cogmed program in children and adolescents with ADHD on working memory, inhibition, non-verbal reasoning, attention functioning, ADHD symptoms and academic achievement. All existing studies on the subject that included a control group (n = 8) are reviewed.ResultsIt is clear from most studies that Cogmed training program increases and verbal and visuospatial working memory (or the phonological loop and visuospatial sketchpad in Baddeley's model (1986, 2007), among ADHD participants. However, transfer of learning is not demonstrated on other components of working memory that are not directly targeted by the program such as the central executive described in Baddeley's model or the secondary memory defined by Unsworth & Engle (2007). With regards to far transfer measures, results are controversial for inhibition, non-verbal reasoning, ADHD symptoms reported by parents, and reading abilities. No improvement is demonstrated for attentional capacities, ADHD symptoms reported by teachers and mathematic reasoning.ConclusionCogmed training improves verbal and visuospatial working memory, two cognitive functions that play an important role in ADHD. However, Cogmed's exercises need to be modified in order to train more complex working memory components such as the central executive (Baddeley, 1986, 2007) and the secondary memory (Unsworth & Engle, 2007), which are more impaired in ADHD than the phonological loop and visuospatial sketchpad. Another approach would be to design programs that can tackle a larger range of cognitive functions that are impaired in ADHD (e.g., inhibition). In future, studies evaluating such modified programs, direct observation instruments that are more sensitive to short-term changes need to be included. Follow-up measures should also be systematically included.     

Task rules, working memory, and fluid intelligence

Many varieties of working memory have been linked to fluid intelligence. In Duncan et al. (Journal of Experimental Psychology:General 137:131-148, 2008), we described limited working memory for new task rules: When rules are complex, some may fail in their control of behavior, though they are often still available for explicit recall. Unlike other kinds of working memory, load is determined in this case not by real-time performance demands, but by the total complexity of the task instructions. Here, we show that the correlation with fluid intelligence is stronger for this aspect of working memory than for several other, more traditional varieties-including simple and complex spans and a test of visual short-term memory. Any task, we propose, requires construction of a mental control program that aids in segregating and assembling multiple task parts and their controlling rules. Fluid intelligence is linked closely to the efficiency of constructing such programs, especially when behavior is complex and novel.     

Input and output for microprocessors

Several alternative strategies for input and output for microprocessors are described, with examples for 8080 machines and the S-100 bus. The strategies are compared in terms of cost, complexity, flexibility, and speed in typical psychology laboratory tasks. Flag testing, interrupt processing, and direct memory access are considered in both parallel and serial modes.     

A word-finding computer program with a dynamic lexical-semantic memory for patients with anomia using an intelligent speech prosthesis

A computer program for a portable microprocessor has been developed which aids anomic patients in finding words given clues about the target word. Over time the lexical-semantic memory is reorganized automatically depending on the frequency of word usage by an individual patient. Words can be added or deleted to fit the patient's idiosyncratic lexicon. A clinical example is given. The program is being tested with a variety of aphasic-anomic patients with major word-finding difficulties.     

Distraction and placebo: two separate routes to pain control

An explosion of recent research has studied whether placebo treatments influence health-related outcomes and their biological markers, but almost no research has examined the psychological processes required for placebo effects to occur. This study tested whether placebo treatment and cognitive distraction reduce pain through shared or independent processes. We tested the joint effects of performance of an executive working memory task and placebo treatment on thermal pain perception. An interactive effect of these two manipulations would constitute evidence for shared mechanisms, whereas additive effects would imply separate mechanisms. Participants (N = 33) reported reduced pain both when they performed the working memory task and when they received the placebo treatment, but the reductions were additive, a result indicating that the executive demands of the working memory task did not interfere with placebo analgesia. Furthermore, placebo analgesia did not impair task performance. Together, these data suggest that placebo analgesia does not depend on active redirection of attention and that expectancy and distraction can be combined to maximize pain relief.