NMDA and muscarinic receptors of the nucleus accumbens have differential effects on taste memory formation

Animals recognize a taste cue as aversive when it has been associated with post-ingestive malaise; this associative learning is known as conditioned taste aversion (CTA). When an animal consumes a new taste and no negative consequences follow, it becomes recognized as a safe signal, leading to an increase in its consumption in subsequent presentations (attenuation of neophobia, AN). It has been shown that the nucleus accumbens (NAcc) has an important role in taste learning. To elucidate the involvement of N-methyl-D-aspartate (NMDA) and muscarinic receptors in the NAcc during safe and aversive taste memory formation, we administrated bilateral infusions of DL-2-amino-5-phosphonopentanoic acid (APV) or scopolamine in the NAcc shell or core respectively. Our results showed that pre-training injections of APV in the NAcc core and shell disrupted aversive but not safe taste memory formation, whereas pre-training injections of scopolamine in the NAcc shell, but not core, disrupted both CTA and AN. These results suggest that muscarinic receptors seem to be necessary for processing taste stimuli for either safe or aversive taste memory, whereas NMDA receptors are only involved in the aversive taste memory trace formation.     

Quantifier comprehension in corticobasal degeneration

In this study, we investigated patients with focal neurodegenerative diseases to examine a formal linguistic distinction between classes of generalized quantifiers, like "some X" and "less than half of X." Our model of quantifier comprehension proposes that number knowledge is required to understand both first-order and higher-order quantifiers. The present results demonstrate that corticobasal degeneration (CBD) patients, who have number knowledge impairments but little evidence for a deficit understanding other aspects of language, are impaired in their comprehension of quantifiers relative to healthy seniors, Alzheimer's disease (AD) and frontotemporal dementia (FTD) patients [F(3,77)=4.98; p<.005]. Moreover, our model attempts to honor a distinction in complexity between classes of quantifiers such that working memory is required to comprehend higher-order quantifiers. Our results support this distinction by demonstrating that FTD and AD patients, who have working memory limitations, have greater difficulty understanding higher-order quantifiers relative to first-order quantifiers [F(1,77)=124.29; p<.001]. An important implication of these findings is that the meaning of generalized quantifiers appears to involve two dissociable components, number knowledge and working memory, which are supported by distinct brain regions.     

CBT intensity and outcome for panic disorder in a primary care setting

A hybrid efficacy-effectiveness design in which participants (n = 91/93) were retained in the study regardless of whether or not they received treatment enabled evaluation of CBT intensity in relation to panic disorder in the primary care setting. CBT intensity was operationalized as number of cognitive-behavioral therapy sessions, number of follow-up booster phone calls, and secondarily, as number of cognitive behavioral coping and exposure strategies. Baseline psychosocial and demographic predictors of CBT intensity were analyzed first. Severity of anxiety sensitivity predicted number of cognitive behavioral sessions, but no baseline variables predicted number of follow-up booster phone calls or number of coping and exposure strategies. Multivariate logistic and linear regressions were used to evaluate the degree to which treatment intensity predicted 3-month and 12-month outcomes (anxiety sensitivity, phobic avoidance, depressive symptoms, disability, and medical and mental health functioning) after controlling for potential confounding baseline variables. Number of cognitive behavioral therapy sessions predicted lower anxiety sensitivity at 3 and 12 months, and number of follow-up booster phone calls predicted lower anxiety sensitivity, less phobic avoidance, and less depression at 12 months. These findings indicate that "dose" of psychotherapy was an important predictor of outcome. The significance of follow-up booster phone contact is discussed as an index of continued self-management of panic and anxiety following acute treatment.     

Large-scale neural network for sentence processing

Our model of sentence comprehension includes at least grammatical processes important for structure-building, and executive resources such as working memory that support these grammatical processes. We hypothesized that a core network of brain regions supports grammatical processes, and that additional brain regions are activated depending on the working memory demands associated with processing a particular grammatical feature. We used functional magnetic resonance imaging (fMRI) to test this hypothesis by comparing cortical activation patterns during coherence judgments of sentences with three different syntactic features. We found activation of the ventral portion of left inferior frontal cortex during judgments of violations of each grammatical feature. Increased recruitment of the dorsal portion of left inferior frontal cortex was seen during judgments of violations of specific grammatical features that appear to involve a more prominent working memory component. Left posterolateral temporal cortex and anterior cingulate were also implicated in judging some of the grammatical features. Our observations are consistent with a large-scale neural network for sentence processing that includes a core set of regions for detecting and repairing several different kinds of grammatical features, and additional regions that appear to participate depending on the working memory demands associated with processing a particular grammatical feature.     

The Nature and Time Course of Pragmatic Plausibility Effects

The experiments reported in this article used a delayed same/different sentence matching task with concurrent measurement of eye movements to investigate the nature of the plausibility effect. The results clearly show that plausibility effects are not due to low level lexical associative processes, but arise as a consequence of the processing of the earliest or most basic form of sentential meaning. In fact, when sentential implausibility and lexical association are varied simultaneously, it is only sentential implausibility that exerts an effect. Effects of implausibility occur rapidly—sometimes parafoveally—and are localised in the regions of the sentence where the implausibility occurs, suggesting an incremental interpretive process progressing on a roughly word-by-word basis. It is suggested that plausibility effects result from the operation of a heuristically-driven process of sentential interpretation. This appears to behave in a ‘modular’ fashion, despite being influenced by real world knowledge and probabilities.Particular thanks are due to Ken Forster for kindling the ideas which led to much of this work and to Merrill Garrett for posing impossible challenges, which, probably to everyone’s surprise, could in fact be met. I am also much indebted to Claire Boissiere, Emma Clayes, Clare Dobbin, Alan Kennedy, Julie-Ann Marshall, Ashley Murray, and Murray Rowan for their collaboration in this research.     

A cognitive architecture that combines internal simulation with a global workspace

This paper proposes a brain-inspired cognitive architecture that incorporates approximations to the concepts of consciousness, imagination, and emotion. To emulate the empirically established cognitive efficacy of conscious as opposed to non-conscious information processing in the mammalian brain, the architecture adopts a model of information flow from global workspace theory. Cognitive functions such as anticipation and planning are realised through internal simulation of interaction with the environment. Action selection, in both actual and internally simulated interaction with the environment, is mediated by affect. An implementation of the architecture is described which is based on weightless neurons and is used to control a simulated robot.     

A smart unconscious? Procedural origins of automatic partner attitudes in marriage

The paper examines potential origins of automatic (i.e., unconscious) attitudes toward one’s marital partner. It tests the hypothesis that early experiences in conflict-of-interest situations predict one’s later automatic inclination to approach (or avoid) the partner. A longitudinal study linked daily experiences in conflict-of-interest situations in the initial months of new marriages to automatic evaluations of the partner assessed four years later using the Implicit Associations Test. The results revealed that partners who were initially (1) treated less responsively and (2) evidenced more self-protective and less connectedness-promoting “if-then” contingencies in their thoughts and behavior later evidenced less positive automatic partner attitudes. However, these factors did not predict changes in love, satisfaction, or explicit beliefs about the partner. The findings hint at the existence of a “smart” relationship unconscious that captures behavioral realities conscious reflection can miss.     

Group Counseling and Group Psychotherapy with Rehabilitation Clients

An instrument designed to measure components of two distinct alcoholism aftercare treatments was developed and evaluated for reliability and validity. Trained judges reliably rated audiotaped samples of coping skills and interactional group therapy sessions. Coping skills groups engaged in significantly more education and skill training, problem solving, and role playing. Interactional groups showed more interpersonal learning, expression/exploration of feelings, and here-and-now focus. Groups that employed more education and skill training, less expression and exploration of feelings, and less her e-and-now focus were associated with fewer members reporting subsequent drinking-related problems. None of the ratings of group activities was related to abstinence.