A social neuroscience approach to self and social categorisation: A new look at an old issue

We take a social neuroscience approach to self and social categorisation in which the current self-categorisation(s) is constructed from relatively stable identity representations stored in memory (such as the significance of one's social identity) through iterative and interactive perceptual and evaluative processing. This approach describes these processes across multiple levels of analysis, linking the effects of self-categorisation and social identity on perception and evaluation to brain function. We review several studies showing that self-categorisation with an arbitrary group can override the effects of more visually salient, cross-cutting social categories on social perception and evaluation. The top-down influence of self-categorisation represents a powerful antecedent-focused strategy for suppressing racial bias without many of the limitations of a more response-focused strategy. Finally we discuss the implications of this approach for our understanding of social perception and evaluation and the neural substrates of these processes.     

Studying Early Adolescents' Academic Motivation,Social-Emotional Functioning,and Engagement in Learning: Variable- and Person-Centered Approaches

This study used variable- and person-centered data analytic techniques to examine how early adolescents' academic motivation and social-emotional functioning were associated with their self-reported cognitive and behavioral engagement in the middle school classroom. Regression results showed that both motivational and mental health constructs contributed to the prediction of individual differences in classroom engagement. Person-centered analyses revealed between group variation in classroom engagement as a function of differing patterns of motivation and mental health among different subgroups of adolescents. Convergent and complementary information on these subgroups was provided by using two different grouping approaches. Findings are discussed in terms of broad patterns of promise or problems during early adolescence.     

Probing the Brain Substrates of Cognitive Processes Responsible for Context Effects on Recognition Memory

ABSTRACT

Context effects on episodic recognition memory involve separable contributions of target-context binding, additive familiarity, and configural constancy. Here we examine whether these factors reflect contributions of processes attributed to different brain substrates. First, we challenged frontal and medial temporal lobe-based cognitive capacities in healthy young adults, employing divided attention tasks at encoding and retrieval, and extended retrieval delay, respectively. Target-context binding effects were specifically attenuated by delay, but not by divided attention. In a second experiment, older adults were identified by neuropsychological testing as having different levels of frontal and medial temporal lobe-dependent cognitive functions. Consistent with Experiment 1, older adults with low medial temporal lobe function exhibited reduced target-context binding effects, but levels of frontal function did not modulate binding effects. These findings indicate that unlike source memory, context effects on memory are associated with the integrity of medial temporal lobe-based processes but not with the integrity of frontal lobe-based processes. Our findings also emphasize the importance of discriminating between functional subgroups in the attempt to characterize memory processes in older adults.     

Noise on, voicing off: Speech perception deficits in children with specific language impairment

Speech perception of four phonetic categories (voicing, place, manner, and nasality) was investigated in children with specific language impairment (SLI) (n = 20) and age-matched controls (n = 19) in quiet and various noise conditions using an AXB two-alternative forced-choice paradigm. Children with SLI exhibited robust speech perception deficits in silence, stationary noise, and amplitude-modulated noise. Comparable deficits were obtained for fast, intermediate, and slow modulation rates, and this speaks against the various temporal processing accounts of SLI. Children with SLI exhibited normal “masking release” effects (i.e., better performance in fluctuating noise than in stationary noise), again suggesting relatively spared spectral and temporal auditory resolution. In terms of phonetic categories, voicing was more affected than place, manner, or nasality. The specific nature of this voicing deficit is hard to explain with general processing impairments in attention or memory. Finally, speech perception in noise correlated with an oral language component but not with either a memory or IQ component, and it accounted for unique variance beyond IQ and low-level auditory perception. In sum, poor speech perception seems to be one of the primary deficits in children with SLI that might explain poor phonological development, impaired word production, and poor word comprehension.     

Retroactive adjustment of perceived time

Accurately timing acoustic events in dynamic scenes is fundamental to scene analysis. To detect events in busy scenes, listeners must often identify a change in the pattern of ongoing fluctuation, resulting in many ubiquitous events being detected later than when they occurred. This raises the question of how delayed detection time affects the manner in which such events are perceived relative to other events in the environment.To model these situations, we use sequences of tone-pips with a time–frequency pattern that changes from regular to random (‘REG–RAND’) or vice versa (‘RAND–REG’). REG–RAND transitions are detected rapidly, but the emergence of regularity cannot be established immediately, and thus RAND–REG transitions take significantly longer to detect. Using a temporal order judgment task, and a light-flash as a temporal marker, we demonstrate that listeners do not perceive the onset of RAND–REG transitions at the point of detection (∼530 ms post transition), but automatically re-adjust their estimate ∼300 ms closer to the nominal transition.These results demonstrate that the auditory system possesses mechanisms that survey the proximal history of an ongoing stimulus and automatically adjust perception to compensate for prolonged detection time, allowing listeners to build meaningful representations of the environment.     

BOLD response to motion verbs in left posterior middle temporal gyrus during story comprehension

A primary focus within neuroimaging research on language comprehension is on the distribution of semantic knowledge in the brain. Studies have shown that the left posterior middle temporal gyrus (LPMT), a region just anterior to area MT/V5, is important for the processing of complex action knowledge. It has also been found that motion verbs cause activation in LPMT. In this experiment we investigated whether this effect could be replicated in a setting resembling real life language comprehension, i.e. without any overt behavioral task during passive listening to a story. During fMRI participants listened to a recording of the story “The Ugly Duckling”. We incorporated a nuisance elimination regression approach for factoring out known nuisance variables both in terms of physiological noise, sound intensity, linguistic variables and emotional content. Compared to the remaining text, clauses containing motion verbs were accompanied by a robust activation of LPMT with no other significant effects, consistent with the hypothesis that this brain region is important for processing motion knowledge, even during naturalistic language comprehension conditions.