Can humans perceive their brain states?

Although the brain enables us to perceive the external world and our body, it remains unknown whether brain processes themselves can be perceived. Brain tissue does not have receptors for its own activity. However, the ability of humans to acquire self-control of brain processes indicates that the perception of these processes may also be achieved by learning. In this study patients learned to control low-frequency components of their EEG: the so-called slow cortical potentials (SCPs). In particular "probe" sessions, the patients estimated the quality of the SCP shift they had produced in the preceding trial. The correspondence between the recorded SCP amplitudes and the subjective estimates increased with training. The ability to perceive the SCPs was related to the ability to control them; this perception was not mediated by peripheral variables such as changes in muscle tonus and cannot be reduced to simple vigilance monitoring. These data provide evidence that humans can learn to perceive the neural activity of their brain. Alternative interpretations are discussed.     

The effects of working memory resource availability on prospective memory: a formal modeling approach

The PAM theory of event-based prospective memory (Smith, 2003; Smith & Bayen, 2004a) proposes that successful prospective memory performance demands upon the interaction of preparatory attentional processes and retrospective memory processes. The two experiments in the current study represent the first application of a formal model to investigate the sensitivity of these underlying processes to variations in working memory resource availability. Multinomial modeling of data from prospective-memory tasks showed that working memory span influenced preparatory attentional processes and retrospective-memory processes.     

Looking behaviour and preference for artworks: The role of emotional valence and location

The position of an item influences its evaluation, with research consistently finding that items occupying central locations are preferred and have a higher subjective value. The current study investigated whether this centre-stage effect (CSE) is a result of bottom-up gaze allocation to the central item, and whether it is affected by item valence. Participants (n = 50) were presented with three images of artistic paintings in a row and asked to choose the image they preferred. Eye movements were recorded for a subset of participants (n = 22). On each trial the three artworks were either similar but different, or were identical and with positive valence, or were identical and with negative valence. The results showed a centre-stage effect, with artworks in the centre of the row preferred, but only when they were identical and of positive valence. Significantly greater gaze allocation to the central and left artwork was not mirrored by equivalent increases in preference choices. Regression analyses showed that when the artworks were positive and identical the participants' last fixation predicted preference for the central art-work, whereas the fixation duration predicted preference if the images were different. Overall the result showed that item valence, rather than level of gaze allocation, influences the CSE, which is incompatible with the bottom-up gaze explanation. We propose that the centre stage heuristic, which specifies that the best items are in the middle, is able to explain these findings and the centre-stage effect.     

A Narrower Scope or a Clearer Lens for Personality? Examining Sources of Observers’ Advantages Over Self‐Reports for Predicting Performance

Emerging studies have shown that observers' ratings of personality predict performance behaviors better than do self-ratings. However, it is unclear whether these predictive advantages stem from (a) use of observers who have a frame of reference more closely aligned with the criterion ("narrower scope") or (b) observers having greater accuracy than targets themselves ("clearer lens"). In a primary study of 291 raters of 97 targets, we found predictive advantages even when observers were personal acquaintances who knew targets only outside of the work context. Integrating these findings with previous meta-analyses showed that colleagues' unique perspectives did not predict incrementally beyond commonly held trait perceptions across all raters (except for openness) and that self-raters who overestimate their agreeableness and conscientiousness perform worse on the job. Broadly, our results suggest that observers have clearer lenses for viewing targets' personality traits, and we discuss the theoretical implications of these findings for studying and measuring personality.     

Empathic accuracy: age differences from adolescence into middle adulthood

ABSTRACT

This study investigated age differences in empathic accuracy, the ability to correctly perceive others’ emotions, in a sample of 151 boys and men from three age groups: adolescents (M_age?=?16 years, SD?=?1.04), young adults (M_age?=?29 years, SD?=?2.78), and middle-aged adults (M_age?=?50 years, SD?=?3.07). All participants viewed nine newly developed film clips, each depicting a boy or a man reliving one of three emotions (anger, sadness, or happiness), while talking about an autobiographical memory. Adolescents and middle-aged men were less accurate than young men, and these age differences were associated with parallel age differences in fluid-mechanical abilities. In addition, age differences in vocabulary, one indicator of crystallized-pragmatic intelligence, were associated with age differences in empathic accuracy in adolescent and young, but not middle-aged, men. Within the limitations of cross-sectional data, this study provides evidence for the idea that empathic accuracy is an effortful task that requires cognitive resources and, thus, may show a normative increase until young adulthood followed by periods of stability and decline in subsequent decades.     

Hierarchical modeling of contingency-based source monitoring: A test of the probability-matching account

According to the probability-matching account of source guessing (Spaniol & Bayen, Journal of Experimental Psychology: Learning, Memory, and Cognition 28:631–651, 2002), when people do not remember the source of an item in a source-monitoring task, they match the source-guessing probabilities to the perceived contingencies between sources and item types. In a source-monitoring experiment, half of the items presented by each of two sources were consistent with schematic expectations about this source, whereas the other half of the items were consistent with schematic expectations about the other source. Participants’ source schemas were activated either at the time of encoding or just before the source-monitoring test. After test, the participants judged the contingency of the item type and source. Individual parameter estimates of source guessing were obtained via beta-multinomial processing tree modeling (beta-MPT; Smith & Batchelder, Journal of Mathematical Psychology 54:167–183, 2010). We found a significant correlation between the perceived contingency and source guessing, as well as a correlation between the deviation of the guessing bias from the true contingency and source memory when participants did not receive the schema information until retrieval. These findings support the probability-matching account.     

Flexible target representations underlie repetition priming in visual search

Repeating target features across consecutive visual search trials can influence response time. Three experiments are reported that show that this repetition priming is dependent on the exact stimulus configuration and feature type. In Experiment 1 the target was defined relative to distractors by its orientation and target colour was task irrelevant. The roles played by these features were reversed in Experiment 2. Repeating target colour across trials speeded responses in both Experiments 1 and 2. Repeating orientation significantly slowed responses in Experiment 1 but had no significant effect in Experiment 2. Existing feature-based and episodic memory-based explanations of priming cannot account for these data, but instead more flexible explanations are required. Experiment 3 showed that significant positive priming results from repeating distractor-defining orientation, indicating that priming of pop-out effects previously reported in the literature may result from combined target and distractor effects.     

Prospective memory in young and older adults: The effects of ongoing-task load

ABSTRACT

Prospective memory involves remembering to perform intended actions in the future. Previous work with the multinomial model of event-based prospective memory indicated that adult age-related differences in prospective-memory performance were due to the prospective (not the retrospective) component of the task (Smith & Bayen, 2006 Smith, R. E. and Bayen, U. J. 2006. The source of age differences in event-based prospective memory: A multinomial modeling approach. Journal of Experimental Psychology: Learning, Memory, and Cognition, 32: 623–635. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar], Journal of Experimental Psychology: Learning, Memory, and Cognition, 32, 623). However, ongoing-task performance was also lower in older adults in that study. In the current study with young and older adults, the difficulty of the ongoing task was manipulated by varying the number of colors per trial to create easier and harder versions of the ongoing task for each age group. The easier version included 2 colors per trial for older adults and 4 colors for young adults. The harder version included 4 colors for older adults and 6 colors for young adults. By adjusting the ongoing-task difficulty, older adults were able to perform the ongoing task as well or better than the young adults. Analyses with the multinomial model revealed that making the ongoing task easier for older adults (or more difficult for young adults) did not eliminate age-related differences in prospective-memory performance and the underlying prospective component.     

Age differences in three facets of empathy: performance-based evidence

This study investigated age differences in cognitive and affective facets of empathy: the ability to perceive another's emotions accurately, the capacity to share another's emotions, and the ability to behaviorally express sympathy in an empathic episode. Participants, 80 younger (M(age) = 32 years) and 73 older (M(age) = 59 years) adults, viewed eight film clips, each portraying a younger or an older adult thinking-aloud about an emotionally engaging topic that was relevant to either younger adults or older adults. In comparison to their younger counterparts, older adults generally reported and expressed greater sympathy while observing the target persons; and they were better able to share the emotions of the target persons who talked about a topic that was relevant to older adults. Age-related deficits in the cognitive ability to accurately perceive another's emotions were only evident when the target person talked about a topic of little relevance to older adults. In sum, the present performance-based evidence speaks for multidirectional age differences in empathy.     

Age differences in emotional reactions: arousal and age-relevance count

Recent findings suggest positivity effects in older adults' attention and memory, but few studies have examined such effects on the level of emotional reactivity. In this study, 52 young and 52 older adults rated 172 pictures of the International Affective Picture System, differing in arousal and age-relevance, in terms of valence and discrete emotions. Age differences in the ratio of pleasantness reactions to pleasant pictures vs. unpleasantness reactions to unpleasant pictures as well as age differences in absolute levels of unpleasantness and pleasantness reactions suggest that positivity effects in older adults' subjective emotional reactions are reduced under high arousal. There is also evidence that positivity effects may be restricted to stimuli with low relevance in old age.