High neuromagnetic activation in the left prefrontal and frontal cortices correlates with better memory performance for abstract words

The ability to store and manipulate online information may be enhanced by an inner speech mechanism that draws upon motor brain regions. Neural correlates of this mechanism were examined using event-related functional magnetic resonance imaging (fMRI). Sixteen participants completed two conditions of a verbal working memory task. In both conditions, participants viewed one or two target letters. In the “storage” condition, these targets were held in mind across a delay. Then a probe letter was presented, and participants indicated by button press whether the probe matched the targets. In the “manipulation” condition, participants identified new targets by thinking two alphabetical letters forward of each original target (e.g., f → h). Participants subsequently indicated whether the probe matched the newly derived targets. Brain activity during the storage and manipulation conditions was examined specifically during the delay phase in order to directly compare manipulation versus storage processes. Activations that were common to both conditions, yet disproportionately greater with manipulation, were observed in the left inferior frontal cortex, premotor cortex, and anterior insula, bilaterally in the parietal lobes and superior cerebellum, and in the right inferior cerebellum. This network shares substrates with overt speech and may represent an inner speech pathway that increases activity with greater working memory demands. Additionally, an inverse correlation was observed between manipulation-related brain activity (on correct trials) and test accuracy in the left premotor cortex, anterior insula, and bilateral superior cerebellum. This inverse relationship may represent intensification of inner speech as one struggles to maintain performance levels.     

Age-related differences in the brain areas outside the classical language areas among adults using category decision task

Older adults perform much like younger adults on language. This similar level of performance, however, may come about through different underlying brain processes. In the present study, we evaluated age-related differences in the brain areas outside the typical language areas among adults using a category decision task. Our results showed that similar activation patterns were found in classical language processing areas across the three age groups although regional lateralization indices in Broca’s and Wernicke’s areas decreased with age. The greatest differences, however, among the three groups were found primarily in the brain areas not associated with core language functioning including the hippocampus, middle frontal gyrus, ventromedial frontal cortex, medial superior parietal cortex and posterior cingulate cortex. Therefore, the non-classical language areas may exhibit an age-related difference between three age groups while the subjects show a similar activation pattern in the core, primary language processing during a semantic decision task.     

Metaphorically feeling: comprehending textural metaphors activates somatosensory cortex

Conceptual metaphor theory suggests that knowledge is structured around metaphorical mappings derived from physical experience. Segregated processing of object properties in sensory cortex allows testing of the hypothesis that metaphor processing recruits activity in domain-specific sensory cortex. Using functional magnetic resonance imaging (fMRI) we show that texture-selective somatosensory cortex in the parietal operculum is activated when processing sentences containing textural metaphors, compared to literal sentences matched for meaning. This finding supports the idea that comprehension of metaphors is perceptually grounded.     

Resting EEG in alpha and beta bands predicts individual differences in attentional blink magnitude

Accuracy for a second target (T2) is reduced when it is presented within 500 ms of a first target (T1) in a rapid serial visual presentation (RSVP) - an attentional blink (AB). There are reliable individual differences in the magnitude of the AB. Recent evidence has shown that the attentional approach that an individual typically adopts during a task or in anticipation of a task, as indicated by various measures, predicts individual differences in the AB deficit. It has yet to be observed whether indices of attentional approach when not engaged in a goal-directed task are also relevant to individual differences in the AB. The current studies investigated individual differences in the AB by examining their relationship with attention at rest using quantitative measures of EEG. Greater levels of alpha at rest were associated with larger AB magnitudes, where greater levels of beta at rest were associated with smaller AB magnitudes. Furthermore, individuals with more beta than alpha demonstrated a smaller AB effect than individuals with more alpha than beta. Our results suggest that greater attentional engagement at rest, when not engaged in a goal-directed task, is associated with smaller AB magnitudes.     

Perceiving age and gender in unfamiliar faces: an fMRI study on face categorization

Efficient processing of unfamiliar faces typically involves their categorization (e.g., into old vs. young or male vs. female). However, age and gender categorization may pose different perceptual demands. In the present study, we employed functional magnetic resonance imaging (fMRI) to compare the activity evoked during age vs. gender categorization of unfamiliar faces. In different blocks, participants performed age and gender classifications for old or young unfamiliar faces (50% female respectively). Both tasks elicited activations in the bilateral fusiform gyri (fusiform face area, FFA) and bilateral inferior occipital gyri (occipital face area, OFA). Importantly, the same stimuli elicited enhanced activation during gender as compared to age categorization. This enhancement was significant in the right FFA and the left OFA, and may be related to increased configural processing. Our findings replicate and extend recent work, and shows that the activation of core components of the face processing network is strongly dependent on task demands.     

How equivalent are the action execution,imagery, and observation of intransitive movements? Revisiting the concept of somatotopy during action simulation

Jeannerod (2001) hypothesized that action execution, imagery, and observation are functionally equivalent. This led to the major prediction that these motor states are based on the same action-specific and even effector-specific motor representations. The present study examined whether hand and foot movements are represented in a somatotopic manner during action execution, imagery, and action observation.     

fMRI responses to Jung's Word Association Test: implications for theory,treatment and research

Jung's Word Association Test was performed under fMRI conditions by 12 normal subjects. Pooled complexed responses were contrasted against pooled neutral ones. The fMRI activation pattern of this generic ‘complexed response’ was very strong (corrected Z scores ranging from 4.90 to 5.69). The activation pattern in each hemisphere includes mirror neurone areas that track ‘otherness’ (perspectival empathy), anterior insula (both self‐awareness and emotional empathy), and cingulated gyrus (self‐awareness and conflict‐monitoring). These are the sites described by Siegel and colleagues as the ‘resonance circuitry’ in the brain which is central to mindfulness (awareness of self) and empathy (sense of the other), negotiations between self awareness and the ‘internal other’. But there is also an interhemispheric dialogue. Within 3 seconds, the left hemisphere over‐rides the right (at least in our normal subjects). Mindfulness and empathy are central to good psychotherapy, and complexes can be windows of opportunity if left‐brain hegemony is resisted. This study sets foundations for further research: (i) QEEG studies (with their finer temporal resolution) of complexed responses in normal subjects (ii) QEEG and fMRI studies of complexed responses in other conditions, like schizophrenia, PTSD, disorders of self organization.     

Language difficulties in children adopted internationally: Neuropsychological and functional neural correlates

Children who have experienced deprivation as a result of orphanage care during early development are at increased risk for a number of cognitive, emotional, and social difficulties (MacLean, 2003). This study examined the neuropsychological and behavioral profile of internationally adopted children with language difficulties, one of the most common cognitive challenges (Behen et al., 2008). In addition to neuropsychological testing, fMRI was utilized to examine activation patterns during expressive fluency and receptive language tasks. In comparison to internationally adopted children without language difficulties and nonadopted controls, participants with language difficulty had worse performance on tasks of verbal memory and reasoning, academic skills, and working memory. Behaviorally, all internationally adopted participants, regardless of language ability, had more parent-reported hyperactivity and impulsivity compared with controls. The fMRI tasks revealed reduced activation in traditional language areas in participants with language difficulty. The impact of early adverse experience on later development is discussed.