Andrea Hildebrandt

Complex span versus updating tasks of working memory : the gap is not that deep

How to best measure working memory capacity is an issue of ongoing debate. Besides established complex span tasks, which combine short-term memory demands with generally unrelated secondary tasks, there exists a set of paradigms characterized by continuous and simultaneous updating of several items in working memory, such as the n-back, memory updating, or alpha span tasks. With a latent variable analysis (N = 96) based on content-heterogeneous operationalizations of both task families, the authors found a latent correlation between a complex span factor and an updating factor that was not statistically different from unity (r = .96). Moreover, both factors predicted fluid intelligence (reasoning) equally well. The authors conclude that updating tasks measure working memory equally well as complex span tasks. Processes involved in building, maintaining, and updating arbitrary bindings may constitute the common working memory ability underlying performance on reasoning, complex span, and updating tasks.

What is working memory capacity, and how can we measure it?

A latent variable study examined whether different classes of working-memory tasks measure the same general construct of working-memory capacity (WMC). Data from 270 subjects were used to examine the relationship between Binding, Updating, Recall-N-back, and Complex Span tasks, and the relations of WMC with secondary memory measures, indicators of cognitive control from two response-conflict paradigms (Simon task and Eriksen flanker task), and fluid intelligence. Confirmatory factor analyses support the concept of a general WMC factor. Results from structural-equation modeling show negligible relations of WMC with response-conflict resolution, and very strong relations of WMC with secondary memory and fluid intelligence. The findings support the hypothesis that individual differences in WMC reflect the ability to build, maintain and update arbitrary bindings.

On the specificity of face cognition compared with general cognitive functioning across adult age.

Face cognition is considered a specific human ability, clearly differentiable from general cognitive functioning. Its specificity is primarily supported by cognitive-experimental and neuroimaging research, but recently also from an individual differences perspective. However, no comprehensive behavioral data are available, which would allow estimating lifespan changes of the covariance structure of face-cognition abilities and general cognitive functioning as well as age-differences in face cognition after accounting for interindividual variability in general cognition. The present study aimed to fill this gap. In an age-heterogeneous (18-82 years) sample of 448 adults, we found no factorial dedifferentiation between face cognition and general cognition. Age-related differences in face memory were still salient after taking into account changes in general cognitive functioning. Face cognition thus remains a specific human ability compared with general cognition, even until old age. We discuss implications for models of cognitive aging and suggest that it is necessary to include more explicitly special social abilities in those models.

Structural invariance and age-related performance differences in face cognition.

Perceiving and memorizing faces swiftly and correctly are important social competencies. The organization of these interpersonal abilities and how they change across the life span are still poorly understood. We investigated changes in the mean and covariance structure of face cognition abilities across the adult life span. A sample of 448 participants, with age ranging from 18 to 88 years, completed a battery of 15 face cognition tasks. After establishing a measurement model of face cognition that distinguishes between face perception, face memory, and the speed of face cognition, we used multiple group models and age-weighted measurement models to explore age-related changes. The modeling showed that the loadings and intercepts of all measures are age invariant. The factor means showed substantial decrements with increasing age. Age-related decrements in performance were strongest for the speed of face cognition but were also salient for face perception and face memory. The onset of age decrements is apparent in the 60s for face perception, in the late 40s for face memory, and in the early 30s for speed of face cognition. Implications of these findings on a theoretical and methodological level are discussed, and potential consequences for applied settings are considered.

Facial EMG responses to emotional expressions are related to emotion perception ability.

Although most people can identify facial expressions of emotions well, they still differ in this ability. According to embodied simulation theories understanding emotions of others is fostered by involuntarily mimicking the perceived expressions, causing a “reactivation” of the corresponding mental state. Some studies suggest automatic facial mimicry during expression viewing; however, findings on the relationship between mimicry and emotion perception abilities are equivocal. The present study investigated individual differences in emotion perception and its relationship to facial muscle responses - recorded with electromyogram (EMG) - in response to emotional facial expressions. N° = °269 participants completed multiple tasks measuring face and emotion perception. EMG recordings were taken from a subsample (N° = °110) in an independent emotion classification task of short videos displaying six emotions. Confirmatory factor analyses of the m. corrugator supercilii in response to angry, happy, sad, and neutral expressions showed that individual differences in corrugator activity can be separated into a general response to all faces and an emotion-related response. Structural equation modeling revealed a substantial relationship between the emotion-related response and emotion perception ability, providing evidence for the role of facial muscle activation in emotion perception from an individual differences perspective.

Sex differences in face cognition

Although there is abundant evidence for female superiority in Face Cognition (FC), a number of questions regarding sex differences remain to be addressed. Here we report a reanalysis of data on the level of latent factors, modeled on the basis of an extensive test battery applied to three samples of over 800 adults in all. In independent samples the measurement structure of FC was invariant for both sexes, indicating that the measurement of the construct does not depend on the context variable sex, and investigating mean performance differences will not be biased by measurement issues - a neglected aspect in previous studies. We confirmed female superiority for face perception (FP) and face memory (FM). For the first time we could show that these sex differences prevailed after accounting for sex differences in broadly measured general cognitive functioning and in object perception. Across adult age, sex differences in FM increased due to the rapid decline of this ability in men, whereas performance in women remained stable across adult age. Self-reported social involvement and things-oriented activities moderated sex-differences in FM. Results show that sex differences are salient at the level of specific FC constructs and that they can be partially explained by social involvement.

Test battery for measuring the perception and recognition of facial expressions of emotion.

Despite the importance of perceiving and recognizing facial expressions in everyday life, there is no comprehensive test battery for the multivariate assessment of these abilities. As a first step toward such a compilation, we present 16 tasks that measure the perception and recognition of facial emotion expressions, and data illustrating each tasks difficulty and reliability. The scoring of these tasks focuses on either the speed or accuracy of performance. A sample of 269 healthy young adults completed all tasks. In general, accuracy and reaction time measures for emotion-general scores showed acceptable and high estimates of internal consistency and factor reliability. Emotion-specific scores yielded lower reliabilities, yet high enough to encourage further studies with such measures. Analyses of task difficulty revealed that all tasks are suitable for measuring emotion perception and emotion recognition related abilities in normal populations.

Face and Object Cognition Across Adult Age

We investigated the specificity of face compared with object cognition from an individual differences and aging perspective by determining the amount of overlap between these abilities at the level of latent constructs across age. Confirmatory factor analytic models tested the specificity of speed and accuracy measures for face and object cognition (N = 448; 18 to 88 years). Accuracy measures were distinguishable and slightly dedifferentiated across age, which was not due to loss of visual acuity and contrast sensitivity. There was no face specificity for speed measures. These results support the specificity of face cognition from differential and developmental perspective only for performance accuracy.

Exploiting the intra-subject latency variability from single-trial event-related potentials in the P3 time range: A review and comparative evaluation of methods

HIGHLIGHTSIntra‐subject variability (ISV) is reflected by single trial event‐related potentials (ERPs).We reviewed and compared eight algorithms for measuring ISV on ERP.The methods were applied on both simulated and empirical data.The relations between ISV measured from ERP and ISV from behavior were examined.The latency‐invariant ERP component cluster biases the measurement of ISV. ABSTRACT The intra‐subject variability (ISV) in brain responses during cognitive processing across experimental trials has been recognised as an important facet of neural functionality reflecting an intrinsic neurophysiological characteristic of the brain. In recent decades, ISV in behaviour has been found to be significantly associated with cognitive functioning varying across individuals, development, ages, and pathological conditions. Event‐related potentials (ERPs) measured in single trials are important tools for characterizing ISV at the neural level. However, due to the overlapping spectra of noise and signals, the retrieval of information from single‐trial ERPs related to cognitive processing has been a challenge. We review the major problems that researchers face in the estimation of ISV in single‐trial ERPs. Then, we present an extensive evaluation of several methods of single‐trial latency estimation based on both simulated and real data. The relationships of ISV in ERPs and reaction times are compared between the different single‐trial methods to assess their relative efficiency in predicting task performance from neural signals. The pros and cons of the methods are discussed.

Neurocognitive mechanisms of individual differences in face cognition: A replication and extension

Face cognition performance is related to individual differences in cognitive subprocesses, as reflected in the amplitudes and latencies of event-related brain potentials (ERPs; Herzmann, Kunina, Sommer, & Wilhelm, 2010). In order to replicate and extend these findings, 110 participants were tested on a comprehensive task battery measuring face cognition abilities and established cognitive abilities, followed by ERP recordings in a face-learning-and-recognition task. We replicated the links of the ERP components indicating the speed of structural face encoding (N170 latency) and access to structural representations in memory (early repetition effect [ERE]/N250r) with the accuracy and speed of face cognition and with established cognitive abilities. As a novel result, we differentiated between the accuracy of face perception and face memory on the behavioral and electrophysiological levels and report a relationship between basic visual processes (P100 amplitude) and face memory. Moreover, the brain–behavior relationships for the ERE/N250r held true, even though we eliminated pictorial and perceptual structural codes from the priming effects by using backward masking of the primes with novel unfamiliar faces. On a methodological level, we demonstrated the utility of the latent difference score modeling technique to parameterize ERP difference components (e.g., ERE/N250r) on a latent level and link them to face cognition abilities.