Does the body give the brain an attentional boost? Examining the relationship between attentional and cardiac gating.

Studies on mind-body interactions have largely focused on how mental states modulate bodily physiological responses. Increasing evidence suggests that bodily states also modulate mental states. Here we investigated how both may be integrated in the brain at the resolution of a heartbeat, examining how phasic fluctuations of peripheral blood pressure and central attentional resources combine to influence cognition. We examined the effects of cardiac phase on the performance of two simultaneous tasks: a go/no-go letter detection task where targets were concurrently presented on background faces and a short-term memory face discrimination task. Short-term memory for the background face was better when the initial face was encoded during the systole rather than diastole phase and when it was paired with a target rather than a distractor. There was no significant interaction between cardiac phase and letter detection. These data suggest that peripheral blood pressure and central attention independently regulate cognitive performance.

Modality general and modality specific coding of hedonic valence.

The pleasant or unpleasant qualities that attach to our perceptions help to determine whether we approach or avoid environmental stimuli, shaping their affordances. How do brains create this affective perceptual dimension? The traditional answer is that sensory areas serve only as conduits for external impressions that are then modulated by heteromodal limbic structures in subsequent phases. Here we raise the possibility that, in addition to these well established gain control effects, sensory systems might also have a more direct role in representing the pleasantness component of perception, as supported by several strands of recent brain imaging evidence. In conjunction with a shared valence code that is independent of its sensory origins, valence representations interleaved within sensory brain areas may support finer grained experiential distinctions between how things look, sound, feel, taste and smell good or bad to us, offering a higher dimensional space of evaluative discriminations.

Deletion variant in the ADRA2B gene increases coupling between emotional responses at encoding and later retrieval of emotional memories.

A deletion variant of the ADRA2B gene that codes for the α2b adrenoceptor has been linked to greater susceptibility to traumatic memory as well as attentional biases in perceptual encoding of negatively valenced stimuli. The goal of the present study was to examine whether emotional enhancements of memory associated with the ADRA2B deletion variant were predicted by encoding, as indexed by the subjectively perceived emotional salience (i.e., arousal) of events at the time of encoding. Genotyping was performed on 186 healthy young adults who rated positive, negative, and neutral scenes for level of emotional arousal and subsequently performed a surprise recognition memory task 1 week later. Experience of childhood trauma was also measured, as well as additional genetic variations associated with emotional biases and episodic memory. Results showed that subjective arousal was linked to memory accuracy and confidence for ADRA2B deletion carriers but not for non-carriers. Our results suggest that carrying the ADRA2B deletion variant enhances the relationship between arousal at encoding and subsequent memory for moderately arousing events.

Affective salience can reverse the effects of stimulus-driven salience on eye movements in complex scenes.

In natural vision both stimulus features and cognitive/affective factors influence an observer's attention. However, the relationship between stimulus-driven ("bottom-up") and cognitive/affective ("top-down") factors remains controversial: Can affective salience counteract strong visual stimulus signals and shift attention allocation irrespective of bottom-up features? Is there any difference between negative and positive scenes in terms of their influence on attention deployment? Here we examined the impact of affective factors on eye movement behavior, to understand the competition between visual stimulus-driven salience and affective salience and how they affect gaze allocation in complex scene viewing. Building on our previous research, we compared predictions generated by a visual salience model with measures indexing participant-identified emotionally meaningful regions of each image. To examine how eye movement behavior differs for negative, positive, and neutral scenes, we examined the influence of affective salience in capturing attention according to emotional valence. Taken together, our results show that affective salience can override stimulus-driven salience and overall emotional valence can determine attention allocation in complex scenes. These findings are consistent with the hypothesis that cognitive/affective factors play a dominant role in active gaze control.

Dietary trans fatty acid intake and maternal and infant adiposity.

BACKGROUND/OBJECTIVES: The fatty acid composition in maternal diet and in breastmilk during lactation may be a factor in the development of childhood overweight later in life. To investigate the association between trans fatty acid and adiposity, 96 mother-infant pairs (exclusive breastfed; mixed fed; and formula fed) at 3 months postpartum were interviewed; body composition was measured on site using the BOD POD and PEA POD for mothers and infants, respectively. SUBJECTS/METHODS: This was a cross-sectional study. Participants were recruited via convenience sampling from Athens-Clarke and surrounding counties of the state of Georgia. Data were analyzed using χ(2), analysis of variance and regression. RESULTS: There were no significant differences in maternal percent body fat by feeding group (32.70, 33.70, and 35.73%, for exclusive, mixed and formula feeding, respectively). Exclusively breastfed infants had higher percent body fat (24.87%) compared with their mixed-fed counterparts (22.15%) but not formula-fed infants (23.93). Mothers who consumed at least 4.5 g of trans fatty acids/day were 5.8 times more likely to have body fat ≥ 30% than those consuming less (odds ratio=5.81; 95% confidence interval (CI), 1.05, 32.32), and their infants were over two times more likely (odds ratio=2.13; 95% CI, 0.75, 6.01) to have body fat ≥ 24%. CONCLUSIONS: Trans fatty acid content of the maternal diet may be associated with both maternal and infant body composition in the early postpartum period. More research is warranted regarding maternal dietary and breastmilk fatty acid composition and their effects on maternal and infant body composition and the development of childhood overweight later in life.

In bad taste: evidence for the oral origins of moral disgust.

In common parlance, moral transgressions "leave a bad taste in the mouth." This metaphor implies a link between moral disgust and more primitive forms of disgust related to toxicity and disease, yet convincing evidence for this relationship is still lacking. We tested directly the primitive oral origins of moral disgust by searching for similarity in the facial motor activity evoked by gustatory distaste (elicited by unpleasant tastes), basic disgust (elicited by photographs of contaminants), and moral disgust (elicited by unfair treatment in an economic game). We found that all three states evoked activation of the levator labii muscle region of the face, characteristic of an oralnasal rejection response. These results suggest that immorality elicits the same disgust as disease vectors and bad tastes.

Fewer colds, less asthma? A hypothesis to explain the fall in childhood asthma in the UK.

UK asthma prevalence fell significantly between 1993 and 2000. In children aged <5 years hospital admissions for asthma fell by 52% and primary care presentations in children under 14 years by over 40%. From 1994 to 2000, primary care consultations for acute respiratory infections in all age groups fell by 36%, and for the common cold by 46%. Isolates for respiratory syncytial virus notified to the Health Protection Agency voluntary reporting scheme fell by 56% between 1993 and 2003. Falls in UK birth rate and improvements in living conditions were reported by the Office of National Statistics over this time. The authors hypothesise that the fall in asthma reflects a fall in respiratory infections, the most important proximal trigger for asthma exacerbations, and that this in turn may be related to a fall in household members to a number too low for effective virus transmission. Future research into the prevalence of asthma must consider the effect of changing respiratory virus burden on populations.

Human and computer recognition of facial expressions of emotion.

Neuropsychological and neuroimaging evidence suggests that the human brain contains facial expression recognition detectors specialized for specific discrete emotions. However, some human behavioral data suggest that humans recognize expressions as similar and not discrete entities. This latter observation has been taken to indicate that internal representations of facial expressions may be best characterized as varying along continuous underlying dimensions. To examine the potential compatibility of these two views, the present study compared human and support vector machine (SVM) facial expression recognition performance. Separate SVMs were trained to develop fully automatic optimal recognition of one of six basic emotional expressions in real-time with no explicit training on expression similarity. Performance revealed high recognition accuracy for expression prototypes. Without explicit training of similarity detection, magnitude of activation across each emotion-specific SVM captured human judgments of expression similarity. This evidence suggests that combinations of expert classifiers from separate internal neural representations result in similarity judgments between expressions, supporting the appearance of a continuous underlying dimensionality. Further, these data suggest similarity in expression meaning is supported by superficial similarities in expression appearance.

Positive affect increases the breadth of attentional selection.

The present study examined the thesis that positive affect may serve to broaden the scope of attentional filters, reducing their selectivity. The effect of positive mood states was measured in two different cognitive domains: semantic search (remote associates task) and visual selective attention (Eriksen flanker task). In the conceptual domain, positive affect enhanced access to remote associates, suggesting an increase in the scope of semantic access. In the visuospatial domain, positive affect impaired visual selective attention by increasing processing of spatially adjacent flanking distractors, suggesting an increase in the scope of visuospatial attention. During positive states, individual differences in enhanced semantic access were correlated with the degree of impaired visual selective attention. These findings demonstrate that positive states, by loosening the reins on inhibitory control, result in a fundamental change in the breadth of attentional allocation to both external visual and internal conceptual space.

Transient lupus anticoagulant: an unusual cause of bruising in children.

A child presented with excessive bruising and prolonged activated partial thromboplastin time. Mixing studies in plasma were positive for phospholipid dependence of the anticoagulant, confirming a diagnosis of lupus anticoagulant. Factor II level was reduced. Laboratory findings normalised after three months, with spontaneous resolution of bruising. This case demonstrates a transient antiphospholipid antibody syndrome as a rare presentation of bleeding diathesis in a previously healthy child, and should be considered in children with new onset bruising and prolonged activated partial thromboplastin time.

Dissociated neural representations of intensity and valence in human olfaction.

Affective experience has been described in terms of two primary dimensions: intensity and valence. In the human brain, it is intrinsically difficult to dissociate the neural coding of these affective dimensions for visual and auditory stimuli, but such dissociation is more readily achieved in olfaction, where intensity and valence can be manipulated independently. Using event-related functional magnetic resonance imaging (fMRI), we found amygdala activation to be associated with intensity, and not valence, of odors. Activity in regions of orbitofrontal cortex, in contrast, were associated with valence independent of intensity. These findings show that distinct olfactory regions subserve the analysis of the degree and quality of olfactory stimulation, suggesting that the affective representations of intensity and valence draw upon dissociable neural substrates.

International study in premedical education.

This study surveyed medical school admission deans about the desirability of international study. Most agreed that an international study program in the premedical years was beneficial, but most were neutral concerning science courses taken in international programs.

Effects of phonological length on the attentional blink for words.

The authors tested whether the attentional blink (AB), a deficit in the ability to report a second target appearing within half a second of a first target, may reflect limitations for consolidating visual stimuli into working memory and awareness. Previous research has shown that people are severely limited in the rate that they can identify and report visual events presented in rapid succession. Word length was examined, a variable known to affect verbal working memory. Experiment 1 showed that the AB was modulated by the phonological length of the first target. Phonologically longer pseudowords triggered larger blink deficits. Experiment 2 also demonstrated the word-length effect on the AB using real-world stimuli, anagrams, that controlled for low-level visual differences between conditions. These data support proposals that the AB reflects a difficulty in consolidating information into working memory.

Lesions of the human amygdala impair enhanced perception of emotionally salient events.

Commensurate with the importance of rapidly and efficiently evaluating motivationally significant stimuli, humans are probably endowed with distinct faculties and maintain specialized neural structures to enhance their detection. Here we consider that a critical function of the human amygdala is to enhance the perception of stimuli that have emotional significance. Under conditions of limited attention for normal perceptual awareness-that is, the attentional blink-we show that healthy observers demonstrate robust benefits for the perception of verbal stimuli of aversive content compared with stimuli of neutral content. In contrast, a patient with bilateral amygdala damage has no enhanced perception for such aversive stimulus events. Examination of patients with either left or right amygdala resections shows that the enhanced perception of aversive words depends specifically on the left amygdala. All patients comprehend normally the affective meaning of the stimulus events, despite the lack of evidence for enhanced perceptual encoding of these events in patients with left amygdala lesions. Our results reveal a neural substrate for affective influences on perception, indicating that similar neural mechanisms may underlie the affective modulation of both recollective and perceptual experience.

Contribution of the anteromedial temporal lobes to the evaluation of facial emotion.

Amygdala damage can result in impairments in evaluating facial expressions largely specific to fear. In contrast, right-hemisphere cortical lesions result in a more global deficit in facial emotion evaluation. This study addressed these 2 contrasting findings by investigating amygdala and adjacent cortical contributions to the evaluation of facial emotion in 12 patients with right and 11 patients with left unilateral anteromedial temporal lobectomy (RTL and LTL, respectively) and 23 normal controls. RTL but not LTL patients revealed impaired intensity ratings that included but were not exclusive to fear, with the most severe deficits confined to expressions related to affective states of withdrawal-avoidance. This suggests that affective hemispheric specializations in cortical function may extend to subcortical limbic regions. In addition, the right amygdala and adjacent cortex may be part of a neural circuit representing facial expressions of withdrawal.

Expression without recognition: contributions of the human amygdala to emotional communication.

A growing body of evidence from humans and other animals suggests the amygdala may be a critical neural substrate for emotional processing. In particular, recent studies have shown that damage to the human amygdala impairs the normal appraisal of social signals of emotion, primarily those of fear. However, effective social communication depends on both the ability to receive (emotional appraisal) and the ability to send (emotional expression) signals of emotional state. Although the role of the amygdala in the appraisal of emotion is well established, its importance for the production of emotional expressions is unknown. We report a case study of a patient with bilateral amygdaloid damage who, despite a severe deficit in interpreting facial expressions of emotion including fear, exhibits an intact ability to express this and other basic emotions. This dissociation suggests that a single neural module does not support all aspects of the social communication of emotional state.

Intact recognition of vocal expressions of fear following bilateral lesions of the human amygdala.

A recent case study found that bilateral damage to the amygdala impairs the normal appraisal of vocal expressions of fear. However, the single source of evidence for this auditory emotion-processing impairment is from a patient with extra-amygdaloid damage that may include the basal ganglia, which have been shown to be important for prosody evaluation. In this study we provide evidence of preserved evaluation of vocal expressions of fear in a female patient (S.P.) with bilateral damage to the amygdala but with intact basal ganglia. This same patient has previously been shown to be impaired in the evaluation of facial expressions, including fear. These results indicate that the analysis of nonverbal signals of fear from different input channels are dissociable, being at least partially dependent on different brain structures. We suggest that the amygdala, in conjunction with the basal ganglia, may support the normal appraisal of auditory signals of danger.