Dissociable contributions of left and right dorsolateral prefrontal cortex in planning.

It is well established that the mid-dorsolateral prefrontal cortex (dlPFC) plays a critical role in planning. Neuroimaging studies have yielded predominantly bilateral dlPFC activations, but the existence and nature of functionally specific contributions of left and right dlPFC have remained elusive. In recent experiments, 2 independent parameters have been identified which substantially determine planning: 1) the degree of interdependence between consecutive steps (search depth) and 2) the degree to which the configuration of the goal state renders the order of single steps either clearly evident or ambiguous (goal hierarchy). Thus, search depth affects the actual mental generation and eva…

Assessing Planning Ability Across the Adult Life Span in a Large Population-Representative Sample: Reliability Estimates and Normative Data for the Tower of London (TOL-F) Task

AbstractObjectives:The Tower of London (TOL) test has probably become the most often used task to assess planning ability in clinical and experimental settings. Since its implementation, efforts were made to provide a task version with adequate psychometric properties, but extensive normative data are not publicly available until now. The computerized TOL-Freiburg Version (TOL-F) was developed based on theory-grounded task analyses, and its psychometric adequacy has been repeatedly demonstrated in several studies but often with small and selective samples.Method:In the present study, we now report reliability estimates and normative data for the TOL-F stratified for age, sex, and education …

Reviewing the impact of problem structure on planning: a software tool for analyzing tower tasks.

Cognitive, clinical, and neuroimaging studies on planning abilities most frequently implement the Tower of London task or one of its variants. Yet, cumulating evidence from a series of experiments suggests that the commonly used approximation of problem difficulty in terms of the minimum number of moves for goal attainment is too coarse a measure for the underlying cognitive operations, and in some cases may be even misleading. Rather, problem difficulty can be more specifically characterized by a set of structural task parameters such as the number and nature of optimal and suboptimal solution paths, the required search depths, the patterns of intermediate and goal moves, goal hierarchies …

Differential impact of continuous theta-burst stimulation over left and right DLPFC on planning

Most neuroimaging studies on planning report bilateral activations of the dorsolateral prefron- tal cortex (dlPFC). Recently, these concurrent activations of left and right dlPFC have been shown to dou- ble dissociate with different cognitive demands imposed by the planning task: Higher demands on the extraction of task-relevant information led to stronger activation in left dlPFC, whereas higher demands on the integration of interdependent information into a coherent action sequence entailed stronger activa- tion of right dlPFC. Here, we used continuous theta-burst stimulation (cTBS) to investigate the supposed causal structure-function mapping underlying this double dissociation. Two grou…

Basic operations in working memory: contributions from functional imaging studies.

Abstract Working memory (WM) constitutes a fundamental aspect of human cognition. It refers to the ability to keep information active for further use, while allowing it to be prioritized, modified and protected from interference. Much research has addressed the storage function of WM, however, its ‘working’ aspect still remains underspecified. Many operations that work on the contents of WM do not appear specific to WM. The present review focuses on those operations that we consider “basic” because they operate in the service of memory itself, by providing its basic functionality of retaining information active, in a stable yet flexible way. Based on current process models of WM we review f…

Myopia and Cognitive Performance: Results From the Gutenberg Health Study.

Purpose To analyze the association between myopia and cognitive performance. Methods A cohort of the population-based Gutenberg Health Study included 3819 eligible enrollees between 40 and 79 years. We used the Tower of London (TOL) test to assess cognitive performance. Myopia was defined as a spherical equivalent (SE) ≤ -0.5 diopters (D) via noncycloplegic autorefractometry. We conducted linear mixed models with the SE as the dependent variable and the age, sex, duration of education, and TOL score as covariates. Results Complete data were available for 3452 participants (90.4%). The mean TOL score was 14.0 ± 3.9 in the myopes versus 12.9 ± 4.0 in the nonmyopes (P < 0.001). The mean TOL sc…

fMRI characterization of visual working memory recognition

Encoding and maintenance of information in visual working memory have been extensively studied, highlighting the crucial and capacity-limiting role of fronto-parietal regions. In contrast, the neural basis of recognition in visual working memory has remained largely unspecified. Cognitive models suggest that recognition relies on a matching process that compares sensory information with the mental representations held in memory. To characterize the neural basis of recognition we varied both the need for recognition and the degree of similarity between the probe item and the memory contents, while independently manipulating memory load to produce load-related fronto-parietal activations. fMR…

Transcranial direct current stimulation over left and right DLPFC: Lateralized effects on planning performance and related eye movements.

Left and right dorsolateral prefrontal cortex (dlPFC) were recently found to be differentially affected by unilateral continuous theta-burst stimulation, reflected in an oppositional alteration of initial thinking time (ITT) in the Tower of London planning task. Here, we further explored this finding using bilateral transcranial direct current stimulation (tDCS) and simultaneous tracking of eye movements. Results revealed a decrease in ITT during concurrent cathodal tDCS of left dlPFC and anodal tDCS of right dlPFC. Eye-movement analyses showed that this facilitating tDCS effect was associated with the actual planning phase, thus reflecting a planning-specific impact of stimulation. For the…

Subclinical levels of anxiety but not depression are associated with planning performance in a large population-based sample

BackgroundMajor depression and anxiety disorders are known to negatively influence cognitive performance. Moreover, there is evidence for greater cognitive decline in older adults with generalized anxiety disorder. Except for clinical studies, complex executive planning functions and subclinical levels of anxiety have not been examined in a population-based sample with a broad age range.MethodsPlanning performance was assessed using the Tower of London task in a population-based sample of 4240 participants aged 40–80 years from the Gutenberg Health Study (GHS) and related to self-reported anxiety and depression by means of multiple linear regression analysis.ResultsHigher anxiety ratings we…

Separable neural bases for subprocesses of recognition in working memory.

Working memory supports the recognition of objects in the environment. Memory models have postulated that recognition relies on 2 processes: assessing the degree of similarity between an external stimulus and memory representations and testing the resulting summed-similarity value against a critical level for recognition. Here, we varied the similarity between samples held in working memory and a probe to investigate these 2 processes with magnetoencephalography. Two separable components matched our expectations: First, from 280 ms after probe onset, clearly nonmatching probes differed from both similar nonmatches and matches over left frontal cortex. At 350--400 ms, these signals evolved i…

Association of Type D personality with cognitive functioning in individuals with and without cardiovascular disease: The Gutenberg health study

ObjectiveDistressed (‘Type D’) personality is associated with adverse health outcomes in patients with cardiovascular disease (CVD). While personality traits from the Five-Factor Model are related to cognitive functioning, neither Type D personality nor its underlying traits negative affectivity (NA) and social inhibition (SI) have been investigated regarding cognition. We therefore compared the predictive value of Type D classification and its subcomponents NA and SI on planning performance in individuals with and without CVD.MethodsType D personality traits (DS14) were determined in a population-based sample of 4026 participants (including 549 with CVD) aged 40–80 years from the Gutenberg…

Inter-item distortions in visual working memory

Assessing Planning Ability Across the Adult Life Span: Population-Representative and Age-Adjusted Reliability Estimates for the Tower of London (TOL-F).

Planning ahead the consequences of future actions is a prototypical executive function. In clinical and experimental neuropsychology, disc-transfer tasks like the Tower of London (TOL) are commonly used for the assessment of planning ability. Previous psychometric evaluations have, however, yielded a poor reliability of measuring planning performance with the TOL. Based on theory-grounded task analyses and a systematic problem selection, the computerized TOL-Freiburg version (TOL-F) was developed to improve the task's psychometric properties for diagnostic applications. Here, we report reliability estimates for the TOL-F from two large samples collected in Mainz, Germany (n = 3,770; 40-80 y…

Linking planning performance and gray matter density in mid-dorsolateral prefrontal cortex: Moderating effects of age and sex

Abstract Planning of behavior relies on the integrity of the mid-dorsolateral prefrontal cortex (mid-dlPFC). Yet, only indirect evidence exists on the association of protracted maturation of dlPFC and continuing gains in planning performance post adolescence. Here, gray matter density of mid-dlPFC in young, healthy adults (18–32 years) was regressed onto performance on the Tower of London planning task while accounting for moderating effects of age and sex on this interrelation. Multiple regression analysis revealed an association of planning performance and mid-dlPFC gray matter density that was especially strong in late adolescence and early twenties. As expected, for males better plannin…