Looking both ways through time: the Janus model of lateralized cognition

Existing models of laterality, while often successful at describing circumscribed domains, have not been successful as explanations of the overall patterns of hemispheric asymmetries. It is therefore suggested that a new approach is needed based on shared contributions to adaptive hemispheric roles rather than functional and structural intrahemispheric similarities. This paper proposes a model of laterality, the Janus model, based on evolutionary considerations of complementary hemispheric roles. It is proposed that the left hemisphere has the role of anticipating future scenarios and choosing between them while the right hemisphere has the role of integrating ongoing information into a unitary view of the past in order to immediately detect and respond to novel and unexpected events. Evidence for these complementary roles is provided in research on motor control and semantic priming. Finally, the Janus model is contrasted with efforts to cast the frequency model as a general model of laterality.     

Movement and visual coding: the structure of visuo-spatial working memory

The influential model of verbal working memory (WM) introduced by Baddeley and Hitch (Recent advances in learning and motivation. Academic, New York, 1974) comprised three interacting component parts; an executive controller and two subservient systems. The two subservient systems, one underpinning verbal processing and the other underpinning visual processing are themselves subdivided. In the verbal system, a passive phonological store is maintained by an active phonological loop, which is able to rehearse the material in the passive store. The visual working memory system has traditionally been thought of as having a similar architecture with a passive visual store being maintained by an active store, which codes in terms of movement over space. The paper discusses the evidence for this relationship in visuo-spatial WM and concludes that the architecture does not fit well with the experimental literature. A direction for future research is suggested.     

儿童外显视空间注意转移

采用提示范式探讨了三、六年级儿童的外显视空间注意转移。实验结果表明：内源性提示下儿童表现出显著的提示效度效应,其效度效应量在年龄组间没有显著差异;较短SOAs的外源性提示下,儿童表现出显著的提示效度效应;较长SOAs的外源性提示下儿童没有表现出返回抑制效应。用注意的过滤器理论和对象文件模型讨论了本研究的结果     

The clock as a focus of selective attention in those with primary insomnia: An experimental study using a modified Posner paradigm

Espie and colleagues [(2006). The attention-intention-effort pathway in the development of psychophysiological insomnia: a theoretical review. Sleep Medicine Reviews, 10, 215-245] propose a route into psychophysiological insomnia along the attention-intention-effort pathway which focuses on the inhibition of sleep-wake automaticity. A contributing factor to this is selective attention to sleep (alongside explicit intention to sleep and effort in the sleep engagement process). Following on from previous work on selective attention to sleep [Marchetti, L. M., Biello, S. M., Broomfield, N. M., MacMahon, K. M. A., & Espie, C. A. (2006). Who is pre-occupied with sleep?. A comparison of attention bias in people with psychphysiological insomnia, delayed sleep phase syndrome and good sleepers using the induced change blindness paradigm. Journal of Sleep Research, 15, 212-221; MacMahon, K., Broomfield, N., Macphee, L., & Espie, C. A. (2006). Attention bias for sleep related stimuli in primary insomnia and delayed sleep phase syndrome using the dot-probe task. Sleep, 29, 11] and considering the importance of monitoring both internal and external cues in the maintenance of insomnia, as highlighted in the cognitive model of insomnia [Harvey, A. G. (2002). A cognitive model of insomnia. Behaviour Research and Therapy, 40, 869-893], a cognitive probe task was employed to investigate further the role of the clock as a focus of selective attention in those with primary insomnia.A 2 × 2 between participants design comparing reaction time of individuals with primary insomnia (n = 22) and normal sleepers (n = 22) on a modified Posner paradigm. Responses obtained from a computer task presenting times which fall within a normal sleep period were analysed.Individuals with primary insomnia demonstrated delayed disengagement to the clock (F(1,84) = 6.9, p < 0.05) which is taken as further support for previous research demonstrating that individuals with primary insomnia exhibit an attentional bias to sleep related stimuli.These results lend support to the attention-intention-effort model (Espie et al., 2006) and the cognitive model (Harvey, 2002) both of which recognise the importance of selective attention towards salient stimuli in the maintenance of insomnia. Possible clinical implications of attentional bias to sleep as a marker of psychopathology progression and treatment efficacy are discussed.     

Interacting effects of worry and anxiety on attentional disengagement from threat

Recent work suggests that the ability to disengage attention from threatening information is impaired in people who suffer from anxiety and dysphoria. It has been suggested that this impaired ability to disengage from threat might specifically be associated with the tendency to perseverate about threat (i.e., worry), which is a main characteristic of anxiety disorders and a wide range of other psychopathologies. However, no studies have yet addressed this issue. The present study examined whether trait worry as well as worry intensity after experimental worry induction are associated with impaired ability to disengage attention from threatening cues (angry faces), independently from or in conjunction with anxiety. Sixty-one participants performed a visual cueing experiment that required detection of a target stimulus at one of two possible locations. Prior to the target neutral, happy or angry facial cues appeared at one of these two locations; when there is a relatively long period between the cue and the target (>300 ms), an overall faster responding to invalidly cued trials relative to validly cued trials is believed to indicate inhibition of return (IOR) to a recently attended location. A reduced IOR for angry faces was only found when both trait worry and anxiety were high. When anxiety was kept constant, both trait worry and state worry were associated with enhanced IOR for neutral faces instead. The results seem to suggest that specific threat-related deficiencies in IOR may be a function of the co-occurrence of worry and anxiety.     

Lateralization of visuospatial attention across face regions varies with emotional prosody

It is well-established that linguistic processing is primarily a left-hemisphere activity, while emotional prosody processing is lateralized to the right hemisphere. Does attention, directed at different regions of the talker’s face, reflect this pattern of lateralization? We investigated visuospatial attention across a talker’s face with a dual-task paradigm, using dot detection and language comprehension measures. A static image of a talker was shown while participants listened to speeches spoken in two prosodic formats, emotional or neutral. A single dot was superimposed on the speaker’s face in one of 4 facial regions on half of the trials. Dot detection effects depended on emotion condition—in the neutral condition, discriminability was greater for the right-, than for the left-, side of the face image, and at the mouth, compared to the eye region. The opposite effects occurred in the emotional prosody condition. The results support a model wherein visuospatial attention used during language comprehension is directed by the left hemisphere given neutral emotional prosody, and by the right hemisphere given primarily negative emotional prosodic cues.     

Attention, emotion, and deactivation of default activity in inferior medial prefrontal cortex

Attention deactivates the inferior medial prefrontal cortex (IMPC), but it is uncertain if emotions can attenuate this deactivation. To test the extent to which common emotions interfere with attention, we measured changes of a blood flow index of brain activity in key areas of the IMPC with positron emission tomography (PET) of labeled water (H(15)2O) uptake in brain of 14 healthy subjects. The subjects performed either a less demanding or a more demanding task of attention while they watched neutral and emotive images of people in realistic indoor or outdoor situations. In the less demanding task, subjects used the index finger to press any key when a new image appeared. In the more demanding task, subjects chose the index or middle finger to press separate keys for outdoor and indoor scenes. Compared to the less demanding task, in a global search of all gray matter, the more demanding significantly lowered blood flow (rCBF) in left IMPC, left and right insula, and right amygdala, and significantly raised blood flow in motor cortex and right precuneus. Restricted searches of rCBF changes by emotion, at coordinates of significant effect in previous studies of the medial prefrontal and temporal cortices, revealed significant activation in the fusiform gyrus, independently of the task. In contrast, we found no effect of emotional content in the IMPC, where emotions failed to override the effect of the task. The results are consistent with a role of the IMPC in the selection among competitive inputs from multiple brain regions, as predicted by the theory of a default mode of brain function. The absent emotional interference with the deactivation of the default state suggests that the inferior prefrontal cortex continued to serve the attention rather than submit to the distraction.     

fMR-adaptation and the bilingual brain

fMR-Adaptation, where a pair of identical stimuli elicits a smaller neural response than a pair of dissimilar stimuli has been extensively used to study object identification and classification as well as memory. Thus far this technique has found limited application in evaluating brain areas sensitive to meaning, language and control of language production. These studies are reviewed together with suggestions as to how varying inter-stimulus repetition lag, dimension of interest and evaluating inter-individual differences may shed new light on how different languages are acquired and represented in the brain.     

Sleep deprivation and sustained attention performance: integrating mathematical and cognitive modeling

A long history of research has revealed many neurophysiological changes and concomitant behavioral impacts of sleep deprivation, sleep restriction, and circadian rhythms. Little research, however, has been conducted in the area of computational cognitive modeling to understand the information processing mechanisms through which neurobehavioral factors operate to produce degradations in human performance. Our approach to understanding this relationship is to link predictions of overall cognitive functioning, or alertness, from existing biomathematical models to information processing parameters in a cognitive architecture, leveraging the strengths from each to develop a more comprehensive explanation. The integration of these methodologies is used to account for changes in human performance on a sustained attention task across 88 h of total sleep deprivation. The integrated model captures changes due to time awake and circadian rhythms, and it also provides an account for underlying changes in the cognitive processes that give rise to those effects. The results show the potential for developing mechanistic accounts of how fatigue impacts cognition, and they illustrate the increased explanatory power that is possible by combining theoretical insights from multiple methodologies.     

Learning to attend: a connectionist model of situated language comprehension

Evidence from numerous studies using the visual world paradigm has revealed both that spoken language can rapidly guide attention in a related visual scene and that scene information can immediately influence comprehension processes. These findings motivated the coordinated interplay account ( Knoeferle & Crocker, 2006 ) of situated comprehension, which claims that utterance-mediated attention crucially underlies this closely coordinated interaction of language and scene processing. We present a recurrent sigma-pi neural network that models the rapid use of scene information, exploiting an utterance-mediated attentional mechanism that directly instantiates the CIA. The model is shown to achieve high levels of performance (both with and without scene contexts), while also exhibiting hallmark behaviors of situated comprehension, such as incremental processing, anticipation of appropriate role fillers, as well as the immediate use, and priority, of depicted event information through the coordinated use of utterance-mediated attention to the scene.