Role of left posterior superior temporal gyrus in phonological processing for speech perception and production

Models of both speech perception and speech production typically postulate a processing level that involves some form of phonological processing. There is disagreement, however, on the question of whether there are separate phonological systems for speech input versus speech output. We review a range of neuroscientific data that indicate that input and output phonological systems partially overlap. An important anatomical site of overlap appears to be the left posterior superior temporal gyrus. We then present the results of a new event-related functional magnetic resonance imaging (fMRI) experiment in which participants were asked to listen to and then (covertly) produce speech. In each participant, we found two regions in the left posterior superior temporal gyrus that responded both to the perception and production components of the task, suggesting that there is overlap in the neural systems that participate in phonological aspects of speech perception and speech production. The implications for neural models of verbal working memory are also discussed in connection with our findings.     

Pharmacologic Treatment of Attention-Deficit/Hyperactivity Disorder: Efficacy,Safety and Mechanisms of Action

Studies examining the efficacy, safety and mechanisms of action of agents for the treatment of attention-deficit/hyperactivity disorder (ADHD) are reviewed, with an emphasis on newer agents such as the long acting stimulants and atomoxetine. Recent studies of medications are characterized by large, rigorously diagnosed samples of children, adolescents and adults with ADHD, use of standardized rating scales and extensive safety data. These studies confirm a robust treatment effect for the Food and Drug Administration approved agents ranging from 0.7 to 1.5. The most common short term side effects to the most commonly used agents include insomnia, loss of appetite, and headaches. Despite public controversy and labeling changes to warn of extremely rare cardiovascular and psychiatric side effects, the evidence does not support the hypothesis that medication for ADHD increases risk for sudden death, mania or psychosis. A wide variety of neuroimaging techniques including electrocephalogram (EEG) power, event related potentials (ERP), functional magnetic resonance imaging (fMRI), and positron emission tomography (PET) are beginning to examine the mechanisms of action of medications for ADHD, and implicating the catecholamines and prefrontal and anterior cingulate cortices as prime sites of actions for these agents.     

The neural basis of cognitive control: Response selection and inhibition

The functional neuroanatomy of tasks that recruit different forms of response selection and inhibition has to our knowledge, never been directly addressed in a single fMRI study using similar stimulus–response paradigms where differences between scanning time and sequence, stimuli, and experimenter instructions were minimized. Twelve right-handed participants were scanned on two standard cognitive control tasks, a stimulus–response incompatibility task, and a response inhibition task. A compound trial design allowed comparison of preparing to inhibit an upcoming automatic response to wholly inhibiting an automatic response. Furthermore, inhibiting an automatic response to perform an alternative task-relevant response was compared to wholly inhibiting an automatic response. No differences were found in prefrontal activity when preparing to inhibit an automatic response was compared to wholly inhibiting an automatic response, suggesting a mostly common network. The left inferior frontal gyrus was found to be commonly recruited during both tasks when controlled responses were required, likely due to its role in response selection. In contrast, the right inferior frontal gyrus was found to be more involved when task demands were stronger for response inhibition. Our results are largely consistent with models of cognitive control that postulate that separate psychological constructs, such as response selection and inhibition, are related processes largely served by a common prefrontal network. This prefrontal network is recruited to a greater or lesser extent depending on specific task demands.     

Integrating core conflictual relationship themes in neurobiological assessment of interpersonal processes in psychotherapy

Interpersonal processes are a key target in counselling and psychotherapy. It is of paramount importance to sharpen their assessment using integrated methods. Hence, this methodological paper describes how fields of research in psychotherapy and neuroimaging can be integrated into one novel complementary neurobehavioural paradigm that can be applied to enhance our understanding of interpersonal processes in psychotherapy. To illustrate this integration, we present selected data from a pre–post pilot study where the authors assessed interpersonal processes in brief treatment for borderline personality disorder using the core conflictual relationship theme, functional magnetic resonance imaging (fMRI) and outcome questionnaires. To do so, they measured individual changes in neural activity using an fMRI task pre‐ and post‐treatment where clients gave feedback on the emotional valence of sentences extracted from their own Relationship Anecdotes Paradigm interviews mixed with neutral ones. In this paper, using data from two participants of said study, we discuss how to implement this methodology and what can be achieved in terms of results.     

Advantages of Rhythmic Movements at Resonance: Minimal Active Degrees of Freedom,Minimal Noise,and Maximal Predictability

Using time delay embedding, the authors applied phase space reconstruction to the time series of rhythmic movements of a hand-held pendulum. Subjects (N = 6) produced the manual oscillations about the wrist at the pendulum's resonant frequency and at a higher and a lower frequency. The number of active degrees of freedom required to capture the dynamics of the rhythmic behavior was 3 for the resonant frequency and 4 for each of the nonresonant frequencies. The residual high-dimensional noise was similarly lowest for the resonant frequency. Whereas 33% and 20%, respectively, of the vectors in the phase spaces of the dynamics higher and lower than resonance were unpredictable, only 12% were unpredictable at resonance. Finally, the predictability of the evolving dynamics extended farther into the future for oscillations at the resonant frequency. At resonance, the prediction horizon was 5 times farther than the prediction horizon for the higher than resonance behavior and 2.5 times farther than that for the lower than resonance behavior. The results suggest that, in pendular oscillations of a limb or limb segment, attunement of the central nervous system to the resonant frequency minimizes the variables to be controlled and maximizes the predictability of the rhythmic movement's chaotic dynamics.     

‘Paralysed associations’: countertransference difficulties in recognising meaning in the treatment of children on the autistic spectrum

Children with autism can have a paralysing effect on the clinician’s capacity to associate freely: connections that seem obvious on reflection may be impossible to notice in the child’s presence. The author argues that this situation can be reached by more than one pathway, and that the degree of the child’s bodily and emotional cohesion is an important factor. Children may seek to immobilise the therapist’s thought processes through projective identification, whether to communicate their own experience of paralysis or because these thought processes are equated with a parental intercourse that produces a ‘baby’ (as described by Bion and Britton). Vignettes are offered to illustrate how the therapist may be nudged into overlooking this baby as well as a potentially growing part of the child that is identified with it, with important consequences for development. A second possible pathway appears to involve the much more primitive mechanism of adhesive identification, in which the child’s sense of continuing existence depends on sticking to the therapist’s surface and any movement can lead to a sense of bodily disintegration. In the clinical illustration, the therapist felt physically constrained and unable to recognise links in the material: it is suggested that this was in resonance with the child’s fear that movement, whether physical or mental, meant losing parts of his body and must be avoided at all costs. These levels can mask each other, and it seems essential to attend to both in order to avoid impasse or the overlooking of essential aspects of the child’s experience.     

Silent music reading: Auditory imagery and visuotonal modality transfer in singers and non-singers

In daily life, responses are often facilitated by anticipatory imagery of expected targets which are announced by associated stimuli from different sensory modalities. Silent music reading represents an intriguing case of visuotonal modality transfer in working memory as it induces highly defined auditory imagery on the basis of presented visuospatial information (i.e. musical notes). Using functional MRI and a delayed sequence matching-to-sample paradigm, we compared brain activations during retention intervals (10 s) of visual (VV) or tonal (TT) unimodal maintenance versus visuospatial-to-tonal modality transfer (VT) tasks. Visual or tonal sequences were comprised of six elements, white squares or tones, which were low, middle, or high regarding vertical screen position or pitch, respectively (presentation duration: 1.5 s). For the cross-modal condition (VT, session 3), the visuospatial elements from condition VV (session 1) were re-defined as low, middle or high “notes” indicating low, middle or high tones from condition TT (session 2), respectively, and subjects had to match tonal sequences (probe) to previously presented note sequences. Tasks alternately had low or high cognitive load. To evaluate possible effects of music reading expertise, 15 singers and 15 non-musicians were included. Scanner task performance was excellent in both groups. Despite identity of applied visuospatial stimuli, visuotonal modality transfer versus visual maintenance (VT > VV) induced “inhibition” of visual brain areas and activation of primary and higher auditory brain areas which exceeded auditory activation elicited by tonal stimulation (VT > TT). This transfer-related visual-to-auditory activation shift occurred in both groups but was more pronounced in experts. Frontoparietal areas were activated by higher cognitive load but not by modality transfer. The auditory brain showed a potential to anticipate expected auditory target stimuli on the basis of non-auditory information and sensory brain activation rather mirrored expectation than stimulation. Silent music reading probably relies on these basic neurocognitive mechanisms.     

Role of medial prefrontal cortex in representing one’s own subjective emotional responses: A preliminary study

The medial prefrontal cortex (mPFC) has been implicated in attending to one’s own emotional states, but the role of emotional valence in this context is not understood. We examined valence-specific BOLD activity in a previously validated functional magnetic resonance imaging (fMRI) paradigm. Ten healthy subjects viewed emotional pictures and categorized their experience as pleasant, unpleasant or neutral. All three categories activated a common region within mPFC. Subtraction of neutral from pleasant or unpleasant conditions instead revealed ventromedial PFC (vmPFC), suggesting that this region represents emotional valence. During exteroceptive attention, greater mPFC responses were observed in response to emotional relative to neutral stimuli, consistent with studies implicating mPFC in the top-down modulation of emotion-biased attention. These findings may help to integrate the two proposed roles of mPFC in emotional representation and top-down modulation of subcortical structures.     

Investigations of the optical spectra and EPR g-factors for the tetragonal Ce3+ centers in YPO4 and LuPO4 crystals

The optical spectral band positions and EPR g-factors (g_‖ , g _⊥) for the tetragonal Ce³⁺ centers in YPO₄ and LuPO₄ crystals with the zircon-structure are calculated using a complete diagonalization (of the energy matrix) method (CDM) related to 4f¹ ions in tetragonal symmetry. In this method, the Zeeman interaction term are added to the Hamiltonian in the conventional CDM and so no perturbation calculations are required to obtain the g factors. The crystal-field parameters used in the calculations are obtained from the superposition model in which the local lattice relaxation related to the bonding lengths is considered. The calculated results are in reasonable agreement with the experimental values. It is found that the four observed optical bands for both the systems can be attributed to Ce³⁺ ions in a tetragonal crystal field.     

Hippocampal region-specific contributions to memory performance in normal elderly

To investigate the relationship between regional hippocampal volume and memory in healthy elderly, 147 community-based volunteers, aged 55–83 years, were evaluated using magnetic resonance imaging, the Groton Maze Learning Test, Visual Reproduction and the Rey Auditory Verbal Learning Test. Hippocampal volumes were determined by interactive volumetry. We found greater age-related reduction in the volume of the hippocampal head relative to the tail. Right hippocampal tail volume correlated with spatial memory on the Groton Maze Learning Test while left hippocampal body volume was associated with delayed verbal memory. These associations were independent of age, sex, education and speed of processing and support the notion of functional differentiation along the long axis of the hippocampus.