Mild cognitive impairment (MCI) is frequent in patients with late-life depression. Previous studies indicate that cognitive performance in these patients is not or only marginally improved when they recover from depression. However, recovery from cognitive impairments due to depression may have a longer time course than recovery from affective symptoms. In a group of 34 elderly depressed patients (mean age: 73.4 years) admitted to a gerontopsychiatric day-clinic, severity of depression and cognitive performance were assessed before the initiation of treatment and were reassessed 6 months later. At admission, 18 of 34 patients (53%) fulfilled the criteria for MCI, with a preponderance of impairments in short-term memory and visuospatial capabilities. At the 6-month follow-up, cognitive performance had not significantly improved for the entire group; 12 of 27 patients (44%) still were fulfilling the criteria for MCI. No relationships could be ascertained between cognitive impairment or functional level and severity or course of depression. Patients with diurnal variations of the depressive symptomatology were less likely to fully recover from depression.

This study compared NRT-performance in monolingual Dutch and bilingual Turkish–Dutch third-graders using a Dutch Nonword Repetition Task (NRT). Several novel response analyses at the phoneme level were applied to further understand the earlier reported overall accuracy differences in NRT-performance between bilinguals and monolinguals. Analyses in which the retention of phonemes and the retention of their serial order were disentangled revealed that monolinguals outperform bilinguals with respect to the retention of the phonemes themselves. However, both groups did not differ in their retention of the serial order of correctly recalled phonemes. Furthermore, this study confirms that expressive vocabulary skills do affect overall NRT-performance. The results are discussed in light of current short-term memory (STM) models and the role of long-term phonological knowledge in NRT tasks.

Simultaneous interpretation is a cognitively demanding process that requires a high level of language management. Previous studies on bilinguals have suggested that extensive practice managing two languages leads to enhancements in cognitive control. Thus, interpreters may be expected to show benefits beyond those seen in bilinguals, either as an extension of previously-seen benefits or in areas specific to interpretation. The present study examined professional interpreters (N = 23) and matched multilinguals (N = 21) on memory tests, the color-word Stroop task, the Attention Network Test, and a non-linguistic task-switching paradigm. The interpreters did not show advantages in conflict resolution or switching cost where bilingual benefits have been noted. However, an interpretation-specific advantage emerged on the mixing cost in the task-switching paradigm. Additionally, the interpreters had larger verbal and spatial memory spans. Interpreters do not continue to garner benefits from bilingualism, but they do appear to possess benefits specific to their experience with simultaneous interpretation.

Logopenic progressive aphasia (LPA) is a form of primary progressive aphasia (PPA) characterized by hesitant speech with marked impairment in naming and repetition. LPA is associated with brain atrophy in the left temporal and inferior parietal cortices and is predominantly associated with Alzheimer's disease (AD) pathology. In contrast to LPA, “typical” AD is commonly associated with episodic memory disturbance and bilateral medial temporal lobe atrophy. Recent evidence suggests verbal short-term memory is more impaired than visuospatial short-term memory in LPA. This study investigated verbal and visuospatial short-term memory in 12 LPA and 12 AD patients matched for disease severity, and in 12 age- and education-matched healthy controls. Overall, both patient groups showed significantly reduced verbal and visuospatial spans compared with controls. In addition, LPA patients performed significantly worse than AD patients on both forward and backward conditions of the Digit Span task. In contrast, no difference was present between patient groups on either version of the Spatial Span task. Importantly, LPA patients showed better visuospatial than verbal span whereas AD patients and controls did not differ across modality. This study demonstrates the specificity of the short-term memory disturbance in LPA, which arises from a breakdown of the phonological system. (JINS, 2012, 19, 1–7)

In this paper we explore the use of Answer Set Programming (ASP) to formalize, and reason about, psychological knowledge. In the field of psychology, a considerable amount of knowledge is still expressed using only natural language. This lack of a formalization complicates accurate studies, comparisons, and verification of theories. We believe that ASP, a knowledge representation formalism allowing for concise and simple representation of defaults, uncertainty, and evolving domains, can be used successfully for the formalization of psychological knowledge. To demonstrate the viability of ASP for this task, in this paper we develop an ASP-based formalization of the mechanics of Short-Term Memory. We also show that our approach can have rather immediate practical uses by demonstrating an application of our formalization to the task of predicting a user's interaction with a graphical interface.

Human agents draw a variety of inferences effortlessly, spontaneously, and with remarkable efficiency – as though these inferences were a reflexive response of their cognitive apparatus. Furthermore, these inferences are drawn with reference to a large body of background knowledge. This remarkable human ability seems paradoxical given the complexity of reasoning reported by researchers in artificial intelligence. It also poses a challenge for cognitive science and computational neuroscience: How can a system of simple and slow neuronlike elements represent a large body of systemic knowledge and perform a range of inferences with such speed? We describe a computational model that takes a step toward addressing the cognitive science challenge and resolving the artificial intelligence paradox. We show how a connectionist network can encode millions of facts and rules involving n-ary predicates and variables and perform a class of inferences in a few hundred milliseconds. Efficient reasoning requires the rapid representation and propagation of dynamic bindings. Our model (which we refer to as SHRUTI) achieves this by representing (1) dynamic bindings as the synchronous firing of appropriate nodes, (2) rules as interconnection patterns that direct the propagation of rhythmic activity, and (3) long-term facts as temporal pattern-matching subnetworks. The model is consistent with recent neurophysiological evidence that synchronous activity occurs in the brain and may play a representational role in neural information processing. The model also makes specific psychologically significant predictions about the nature of reflexive reasoning. It identifies constraints on the form of rules that may participate in such reasoning and relates the capacity of the working memory underlying reflexive reasoning to biological parameters such as the lowest frequency at which nodes can sustain synchronous oscillations and the coarseness of synchronization.

A theory is presented of how global visual interactions between depth, length, lightness, and form percepts can occur. The theory suggests how quantized activity patterns which reflect these visual properties can coherently fill-in, or complete, visually ambiguous regions starting with visually informative data features. Phenomena such as the Cornsweet and Craik–O'Brien effects, phantoms and subjective contours, binocular brightness summation, the equidistance tendency, Emmert's law, allelotropia, multiple spatial frequency scaling and edge detection, figure-ground completion, coexistence of depth and binocular rivalry, reflectance rivalry, Fechner's paradox, decrease of threshold contrast with increased number of cycles in a grating pattern, hysteresis, adaptation level tuning, Weber law modulation, shift of sensitivity with background luminance, and the finite capacity of visual short term memory are discussed in terms of a small set of concepts and mechanisms. Limitations of alternative visual theories which depend upon Fourier analysis, Laplacians, zero-crossings, and cooperative depth planes are described. Relationships between monocular and binocular processing of the same visual patterns are noted, and a shift in emphasis from edge and disparity computations toward the characterization of resonant activity-scaling correlations across multiple spatial scales is recommended. This recommendation follows from the theory's distinction between the concept of a structural spatial scale, which is determined by local receptive field properties, and a functional spatial scale, which is defined by the interaction between global properties of a visual scene and the network as a whole. Functional spatial scales, but not structural spatial scales, embody the quantization of network activity that reflects a scene's global visual representation. A functional scale is generated by a filling-in resonant exchange, or FIRE, which can be ignited by an exchange of feedback signals among the binocular cells where monocular patterns are binocularly matched.

This paper considers the use of memory models and machine intelligence, to dynamically update a computer based representation of the occupancy of a small building. The input to the model is derived from very simple, single bit, movement sensors in each room of the premises.I It will be shown that the information derived from these sensors can provide adequate data for a building control scheme.

Short and Long Term memory models of man will be briefly reviewed. Working models for Short and Long Term memory will be discussed, which have evolved from the earlier work but which have been tuned to fit the machine level constraints of this type of application.

A review of the performance of a working pilot installation will be given. A performance measure will be derived and initial figures using this measure will be presented.

It has been proposed that differences in digit span performance between English and Spanish speakers are due to the greater number of syllables per digit in the Spanish language. To test this hypothesis, we studied the performance of 30 English- and 30 Spanish-speaking elders on the Wcchsler Adult Intelligence Scale-Revised (WAIS-R) Digit Span Subtest, a modified digit span test that was linguistically comparable for both languages, and the Corsi Block Test. Consistent with previous reports, we found that English speakers scored significantly higher than Spanish speakers on WAIS-R Digit Span Forward. Group differences were reduced on the modified Digit Span Forward, but remained significant. English and Spanish speakers scored comparably on Digit Span Backward (WAIS-R and modified) and Visual Span. We suggest that although differences in the number of syllables per digit string are in part responsible for the lower performance of Spanish speakers on Digit Span Forward, cultural and educational issues also contribute to the observed differences between English and Spanish speakers. (J1NS, 1996, 2, 105–110.)

Seventeen patients diagnosed with Parkinson's disease completed a complex computer-based task that involved planning and management while also performing an attention-demanding secondary task. The tasks were performed concurrently, but it was necessary to switch from one to the other. Performance was compared to a group of healthy age-matched control participants and a group of young participants. Parkinson's patients performed better than the age-matched controls on almost all measures and as well as the young controls in many cases. However, the Parkinson's patients achieved this by paying relatively less attention to the secondary task and focusing attention more on the primary task. Thus, Parkinson's patients can apparently improve their performance on some aspects of a multidimensional task by simplifying task demands. This benefit may occur as a consequence of their inflexible exaggerated attention to some aspects of a complex task to the relative neglect of other aspects. (JINS, 2008, 14, 257–265.)

The aim of the present study was to assess the functioning of the different subsystems of working memory after severe traumatic brain injury (TBI). A total of 30 patients with severe chronic TBI and 28 controls received a comprehensive assessment of working memory addressing the phonological loop (forward and backward digit span; word length and phonological similarity effects), the visuospatial sketchpad (forward and backward visual spans), and the central executive (tasks requiring simultaneous storage and processing of information, dual-task processing, working memory updating). Results showed that there were only marginal group differences regarding the functioning of the two slave systems, whereas patients with severe TBI performed significantly poorer than controls on most central executive tasks, particularly on those requiring a high level of controlled processing. These results suggest that severe TBI is associated with an impairment of executive aspects of working memory. The anatomic substrate of this impairment remains to be elucidated. It might be related to a defective activation of a distributed network, including the dorsolateral prefrontal cortex. (JINS, 2007, 13, 770–780.)

Spina bifida meningomyelocele (SBM) is a neurodevelopmental disorder associated with adequate development of word reading and single word comprehension, but deficient text and discourse comprehension. Studies of comprehension in children with SBM are reviewed in relation to a comprehension model in which meanings are either activated from the surface code or constructed through resource-intensive integration and revision processes to form representations of the text base and models of the situation described by the text. Two new studies probed the construction of situation models in SBM. Experiment 1 tested the ability to build spatial and affective situation models from single sentences in 86 children with SBM (8 to 18 years of age) and 37 control children (8 to 16 years of age). Experiment 2 tested the ability to integrate across sentences to build spatial situation models in 15 children with SBM and 15 age-matched controls. Compared to age peers, children with SBM did not construct situation models that required integration of information across sentences, even though they could construct such models from single sentences. The data bear on the distinctive SBM neurocognitive profile, and more generally, on the significance of integration processes for the constructive aspects of language comprehension. (JINS, 2007, 13, 854–864.)

Executive functions are highly sensitive to the effects of aging and other conditions affecting frontal lobe function. Yet there are few validated interventions specifically designed to address executive functions, and, to our knowledge, none validated in a healthy aging sample. As part of a large-scale cognitive rehabilitation randomized trial in 49 healthy older adults, a modified Goal Management Training program was included to address the real-life deficits caused by executive dysfunction. This program emphasized periodic suspension of ongoing activity to establish goal hierarchies and monitor behavioral output. Tabletop simulated real-life tasks (SRLTs) were developed to measure the processes targeted by this intervention. Participants were randomized to two groups, one of which received the intervention immediately and the other of which was wait-listed prior to rehabilitation. Results indicated improvements in SRLT performance and self-rated executive deficits coinciding with the training in both groups. These gains were maintained at long-term follow-up. Future research will assess the specificity of these effects in patient groups (JINS, 2007, 13, 143–152.)

Working memory and information processing speed were examined in children with myelomeningocele and shunted hydrocephalus using the Children's Paced Auditory Serial Addition Test (CHIPASAT). The CHIPASAT was administered to 31 children with myelomeningocele and shunted hydrocephalus and 27 healthy siblings, all between 8 and 15 years of age. They also completed other standardized measures of working memory and processing speed. Children with myelomeningocele made fewer correct responses than siblings, although the magnitude of group differences declined as the rate of stimulus presentation increased. Children with myelomeningocele also made fewer consecutive correct responses and were more likely to provide correct but nonconsecutive responses, suggesting that they responded in a way that circumvents the working memory demands of the task. Standardized measures of processing speed and working memory accounted for significant variance in CHIPASAT performance after controlling for age, group membership, math skill, and general intellectual functioning. The results indicate that children with myelomeningocele and shunted hydrocephalus display deficits in working memory and information processing speed, and suggest that the CHIPASAT may provide a valid measure of these skills. (JINS, 2006, 12, 305–313.)

Although the prefrontal cortex (PFC) is consistently found to be associated with various working memory processes, the necessity of the PFC for such processes remains unclear. To elucidate PFC contributions to storage and rehearsal/maintenance processes engaged during verbal working memory function, we assessed behavior of patients with lesions to the left or right lateral PFC, and neural activity of healthy young subjects during fMRI scanning, during performance of working memory tasks. We found that PFC lesions did not affect storage processes—which is consistent with the notion that posterior cortical networks can support simple retention of information. We also found that PFC lesions did not affect rehearsal/maintenance processes, which was in contrast to our finding that healthy subjects performing a verbal delayed recognition task showed bilateral PFC activation. These combined imaging and behavioral data suggest that working memory rehearsal/maintenance processes may depend on both hemispheres, which may have implications for recovery of function and development of rehabilitation therapies after frontal injury. (JINS, 2006, 12, 248–260.)

High temporal resolution event-related brain potential and electroencephalographic coherence studies of the neural substrate of short-term storage in working memory indicate that the sustained coactivation of both prefrontal cortex and the posterior cortical systems that participate in the initial perception and comprehension of the retained information are involved in its storage. These studies further show that short-term storage mechanisms involve an increase in neural synchrony between prefrontal cortex and posterior cortex and the enhanced activation of long-term memory representations of material held in short-term memory. This activation begins during the encoding/comprehension phase and evidently is prolonged into the retention phase by attentional drive from prefrontal cortex control systems. A parsimonious interpretation of these findings is that the long-term memory systems associated with the posterior cortical processors provide the necessary representational basis for working memory, with the property of short-term memory decay being primarily due to the posterior system. In this view, there is no reason to posit specialized neural systems whose functions are limited to those of short-term storage buffers. Prefrontal cortex provides the attentional pointer system for maintaining activation in the appropriate posterior processing systems. Short-term memory capacity and phenomena such as displacement of information in short-term memory are determined by limitations on the number of pointers that can be sustained by the prefrontal control systems.