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We assessed the automaticity of emotional face processing with respect to the intentionality criterion, holding that automatic processes are triggered independently of intention. For this purpose, we observed emotion processing in event-related brain potential (ERP) components under five different task conditions. ERP components included the P1, N170, the early posterior negativity (EPN), and the late positive complex (LPC). Enhanced processing at perceptual stages as indicated by P1, N170, and EPN effects occurred independently of intention in angry expressions. In contrast, the emotion-related LPC, a putative manifestation of higher-level, more elaborative processing stages, depended on the intentional state of the participants. This suggests an automatic threat-related processing bias at perceptual stages, while higher cognitive emotion encoding is subject to voluntary control. Moreover, an independent component analyses (ICA) showed that EPN and LPC activity occurred simultaneously, indicating perceptual and higher cognitive emotion encoding to occur in parallel.
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The late positive potential (LPP) elicited by affective stimuli in the event-related brain potential (ERP) is often assumed to be a member of the P3 family. The present study addresses the relationship of the LPP to the classic P3b in a published data set, using a non-parametric permutation test for topographical comparisons, and residue iteration decomposition to assess the temporal features of the LPP and the P3b by decomposing the ERP into several component clusters according to their latency variability. The experiment orthogonally manipulated arousal and valence of words, which were either read or judged for lexicality. High-arousing and positive valenced words induced a larger LPP than low-arousing and negative valenced words, respectively, and the LDT elicited a larger P3b than reading. The experimental manipulation of arousal, valence, and task yielded main effects without any interactions on ERP amplitude in the LPP/P3b time range. The arousal and valence effects partially differed from the task effect in scalp topography; in addition, whereas the late positive component elicited by affective stimuli, defined as LPP, was stimulus-locked, the late positive component elicited by task demand, defined as P3b, was mainly latency-variable. Therefore LPP and P3b manifest different subcomponents.
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Relatively little is known regarding the broad factor of correct decision speed (CDS), which is represented in the theory of fluid and crystallized intelligence. The current study (N = 186) examined the possibility that distinct CDS factors may exist that are specific to the broad ability assessed by the tasks from which the correct response latencies are derived, in this instance fluid and crystallized intelligence (Gf and Gc) tasks. Additionally, the relationships between the correct response latencies and Gf, Gc, and processing speed (Gs) were investigated. Two distinct yet correlated factors of CDS were identified for Gf and Gc tasks, respectively. Both CDS factors were related to their ability factor counterparts, and CDSGc was lowly related to Gs. However, item difficulty moderated the relationships between CDS and the abilities. When item difficulty was considered relative to groups of participants differing in ability level, differences in the speed of responses were found amo
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A number of studies have shown an impact of speed of a developing facial expression of emotion on its recognition and perceived naturalness. Still, the impact of speed at constant, short presentation times, as normally used in many experiments is unclear. In the present study participants classified faces displaying facial expressions of six basic emotions in static and dynamic presentation modes and three different types of neutral movements. Stimuli were created with computer software that allows fine-grained control over action units and dynamic features. Rise times in dynamic expressions varied between 200 and 900 ms. Results replicated classical findings showing better performance for expressions of happiness, and frequent confusions among morphologically similar expressions, and a general dynamic facilitation for most expressions. Importantly, dynamic presentation as such facilitated a more accurate classification, but variations in speed at the fast range studied here had no noticeable effect for expressions of anger, fear, happiness, and surprise. The main exception was sadness, which was best recognised at slow speed and in static pictures, and disgust, which was most unambiguously categorised at fast to moderate speed.
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Attractive faces have a special status, possibly because of evolutionary reasons. We assessed the automaticity of facial attractiveness processing in a dual-task paradigm manipulating the availability of cognitive resources to face processing by a primary tone task presented at varying stimulus onset asynchrony (SOA). In event-related brain potentials, attractive relative to neutral faces induced an increased posterior negativity from 260ms onwards indicating enhanced stimulus encoding at the cortical level. Interestingly, effects of attractive faces on event-related brain potentials were most pronounced at high temporal overlap with the primary task (short stimulus onset asynchrony). This indicates that a shortage of cognitive resources may enhance the processing of attractive faces, revealing hard-wired processing biases of the human information processing system for evolutionarily prepared stimuli.
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Emotional pictures, faces, or words elicit an early posterior negativity (EPN) in the event-related potential, starting around 200–400 ms, followed by a late positive complex (LPC). Occasionally, also very early effects of emotion (VEEEs) are seen prior to 200 ms. The present study examined whether VEEEs can be due to direct links established by reinforcement learning. In the learning session, participants learned to associate previously unknown Chinese words with monetary gain, loss, or neither. In the test session, they were required to distinguish the learned stimuli from novel distracters. Specific to stimuli associated with positive outcome a VEEE, consisting of a posterior positivity, appeared around 150 ms and an LPC between 550 and 700 ms, whereas an EPN was absent. These results show that previous association with reward can induce VEEEs, indicating that emotion effects in ERPs may arise in the absence of biologically preparedness and semantic meaning.
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Emotional meaning impacts word processing. However, it is unclear, at which functional locus this influence occurs and whether and how it depends on word class. These questions were addressed by recording event-related potentials (ERPs) in a lexical decision task with written adjectives, verbs, and nouns of positive, negative, and neutral emotional valence. In addition, word frequency (high vs. low) was manipulated. The early posterior negativity (EPN) in ERPs started earlier for emotional nouns and adjectives than for verbs. Depending on word class, EPN onsets coincided with or followed the lexicality effects. Main ERP effects of emotion overlapped with effects of word frequency between 300 and 550 ms but interacted with them only after 500 ms. These results indicate that in all three word classes examined, emotional evaluation as represented by the EPN has a post-lexical locus, starting already after a minimum of lexical access.
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Human cognitive ability shows consistent, positive associations with fitness components across the life-course. Underlying genetic variation should therefore be depleted by selection, which is not observed. Genetic variation in general cognitive ability (intelligence) could be maintained by a mutation-selection balance, with rare variants contributing to its genetic architecture. This study examines the association between the total number of rare stop-gain/ loss, splice and missense exonic variants and cognitive ability in childhood and old age in the same individuals. Exome array data were obtained in the Lothian Birth Cohorts of 1921 and 1936 (combined N = 1596). General cognitive ability was assessed at age 11 years and in late life (79 and 70 years, respectively) and was modelled against the total number of stop-gain/loss, splice, and missense exonic variants, with minor allele frequency less than or equal to 0.01, using linear regression adjusted for age and sex. In both cohorts and in both the childhood and late-life models, there were no significant associations between rare variant burden in the exome and cognitive ability that survived correction for multiple testing. Contrary to our a priori hypothesis, we observed no evidence for an association between the total number of rare exonic variants and either childhood cognitive ability or late-life cognitive ability.
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Associations between brain cortical tissue volume and cognitive function in old age are frequently interpreted as suggesting that preservation of cortical tissue is the foundation of successful cognitive aging. However, this association could also, in part, reflect a lifelong association between cognitive ability and cortical tissue. We analyzed data on 588 subjects from the Lothian Birth Cohort 1936 who had intelligence quotient (IQ) scores from the same cognitive test available at both 11 and 70 years of age as well as high-resolution brain magnetic resonance imaging data obtained at approximately 73 years of age. Cortical thickness was estimated at 81 924 sampling points across the cortex for each subject using an automated pipeline. Multiple regression was used to assess associations between cortical thickness and the IQ measures at 11 and 70 years. Childhood IQ accounted for more than two-third of the association between IQ at 70 years and cortical thickness measured at age 73 years. This warns against ascribing a causal interpretation to the association between cognitive ability and cortical tissue in old age based on assumptions about, and exclusive reference to, the aging process and any associated disease. Without early-life measures of cognitive ability, it would have been tempting to conclude that preservation of cortical thickness in old age is a foundation for successful cognitive aging when, instead, it is a lifelong association. This being said, results should not be construed as meaning that all studies on aging require direct measures of childhood IQ, but as suggesting that proxy measures of prior cognitive function can be useful to take into consideration.
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Background: intracranial volume (ICV) is commonly used as a marker of premorbid brain size in neuroimaging studies as it is thought to remain fixed throughout adulthood. However, inner skull table thickening would encroach on ICV and could mask actual brain atrophy. Objective: we investigated the effect that thickening might have on the associations between brain atrophy and cognition. Methods: the sample comprised 57 non-demented older adults who underwent structural brain MRI at mean age 72.7 +/- 0.7 years and were assessed on cognitive ability at mean age 11 and 73 years. Principal component analysis was used to derive factors of general cognitive ability (g), information processing speed and memory from the recorded cognitive ability data. The total brain tissue volume and ICV with (estimated original ICV) and without (current ICV) adjusting for the effects of inner table skull thickening were measured. General linear modelling was used to test for associations. Results: all cognitive ability variables were significantly (P < 0.01) associated with percentage total brain volume in ICV measured without adjusting for skull thickening (g: eta(2) = 0.177, speed: eta(2) = 0.264 and memory: eta(2) = 0.132). After accounting for skull thickening, only speed was significantly associated with percentage total brain volume in ICV (eta(2) = 0.085, P = 0.034), not g or memory. Conclusions: not accounting for skull thickening when computing ICV can distort the association between brain atrophy and cognitive ability in old age. Larger samples are required to determine the true effect.
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