bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of giving pacifiers to premature infants and making them listen to lullabies on their transition period for total oral feeding and sucking success
Authors: Yildiz Aynur , Arikan Duygu
Published: June 2011

Aim and objective.  This research aimed to assess the effect of giving pacifiers to premature infants and making them listen to lullabies on the transition period to total oral feeding, their sucking success and their vital signs (peak heart rate, respiration rate and oxygen saturation).

Background.  It is very important that preterm infants start oral feeding as soon as possible to survive and get healthy quickly. Previous studies have shown that by using some external stimuli, premature babies can move to oral feeding at an earlier period than 34th gestational week, have increased daily weight gain and be discharged from hospital earlier.

Design.  In this quasi‐experimental and prospective study, 90 premature infants were studied with 30 premature infants allocated to each of pacifier, lullaby and control groups.

Method.  The research was conducted at a neonatal intensive care clinic and premature unit of a university hospital in the east of Turkey between December 2007–January 2009. The data were collected through demographic information form for premature infants, the LATCH Breastfeeding Charting System and patient monitoring.

Results.  We found that the group who proceeded to the oral feeding in the shortest period was the pacifier group (p < 0·05), followed by the lullaby group and the control group, respectively (p > 0·05). We also found that the highest sucking success was achieved by infants in the pacifier group (p < 0·05) followed by the lullaby group (p > 0·05).

Conclusion.  These results demonstrate that giving pacifiers to premature infants and making them listen to lullabies has a positive effect on their transition period to oral feeding, their sucking success and vital signs (peak heart rate and oxygen saturation).

Relevance to clinical practice.  Neonatal intensive care nurses can accelerate premature infants’ transition to oral feeding and develop their sucking success by using the methods of giving them pacifiers and making them listen to lullabies during gavage feeding.
Steroidogenic Factor 1 and the Central Nervous System
Authors: Büdefeld T. , Tobet S. A. , Majdic G.
Published: June 2011

Steroidogenic factor 1 (SF‐1; officially designated NR5a1) is a member of a nuclear receptor superfamily with important roles in the development of endocrine systems. Studies with global and tissue‐specific (i.e. central nervous system) knockout mice have revealed several roles of SF‐1 in brain. These include morphological effects on the development of the ventromedial nucleus of the hypothalamus and functional effects on body weight regulation through modulation of physical activity, anxiety‐like behaviours and female sexual behaviours. Although such defects are almost certainly a result of the absence of SF‐1 acting as a transcription factor in the hypothalamus, global SF‐1 knockout mice also represent a model for studying the sex differences in the brain that develop in the absence of exposure to foetal sex steroid hormones as a result of the absence of gonads. In the present review, current knowledge of the roles of SF‐1 protein in the central nervous system is discussed.
Measures of linkage disequilibrium among neighbouring SNPs indicate asymmetries across the house mouse hybrid zone
Authors: WANG LIUYANG , LUZYNSKI KEN , POOL JOHN E. , JANOUŠEK VÁCLAV , DUFKOVÁ PETRA , VYSKOČILOVÁ MARTINA M. , TEETER KATHERINE C. , NACHMAN MICHAEL W. , MUNCLINGER PAVEL , MACHOLÁN MILOŠ , PIÁLEK JAROSLAV , TUCKER PRISCILLA K.
Published: June 2011

Theory predicts that naturally occurring hybrid zones between genetically distinct taxa can move over space and time as a result of selection and/or demographic processes, with certain types of hybrid zones being more or less likely to move. Determining whether a hybrid zone is stationary or moving has important implications for understanding evolutionary processes affecting interactions in hybrid populations. However, direct observations of hybrid zone movement are difficult to make unless the zone is moving rapidly. Here, evidence for movement in the house mouseMus musculus domesticus × Mus musculus musculushybrid zone is provided using measures of LD and haplotype structure among neighbouring SNP markers from across the genome. Local populations of mice across two transects in Germany and the Czech Republic were sampled, and a total of 1301 mice were genotyped at 1401 markers from the nuclear genome. Empirical measures of LD provide evidence for extinction and (re)colonization in single populations and, together with simulations, suggest hybrid zone movement because of either geography‐dependent asymmetrical dispersal or selection favouring one subspecies over the other.
TCP14 and TCP15 affect internode length and leaf shape in Arabidopsis
Authors: Kieffer Martin , Master Vera , Waites Richard , Davies Brendan
Published: June 2011

TCP transcription factors constitute a small family of plant‐specific bHLH‐containing, DNA‐binding proteins that have been implicated in the control of cell proliferation in plants. Despite the significant role that is likely to be played by genes that control cell division in the elaboration of plant architecture, functional analysis of this family by forward and reverse genetics has been hampered by genetic redundancy. Here we show that mutants in two related class I TCP genes display a range of growth‐related phenotypes, consistent with their dynamic expression patterns; these phenotypes are enhanced in the double mutant. Together, the two genes influence plant stature by promoting cell division in young internodes. Reporter gene analysis and use of SRDX fusions suggested that TCP14 and TCP15 modulate cell proliferation in the developing leaf blade and specific floral tissues; a role that was not apparent in our phenotypic analysis of single or double mutants. However, when the relevant mutants were subjected to computer‐aided morphological analysis of the leaves, the consequences of loss of either or both genes became obvious. The effects on cell proliferation of perturbing the function of TCP14 and TCP15 vary with tissue, as has been suggested for other TCP factors. These findings indicate that the precise elaboration of plant form is dependent on the cumulative influence of many TCP factors acting in a context‐dependent fashion. The study highlights the need for advanced methods of phenotypic analysis in order to characterize phenotypes and to construct a dynamic model for TCP gene function.
Pityriasis lichenoides et varioliformis acuta: A rare association with the measles, mumps and rubella vaccine
Authors: Gunatheesan Shyamalar , Ferguson John , Moosa Yaaseen
Published: June 2011

The aetiology of pityriasis lichenoides (PL) is unknown. One major pathogenic theory suggests that PL is a lymphoproliferative disease or inflammatory reaction triggered by an antigenic stimulus, such as a virus or other infectious agent. We report the second case of PL et varioliformis acuta (PLEVA) occurring after measles vaccination and the first following the combined measles, mumps, rubella vaccination.
Comparison of the use of 5‐fluorouracil and bevacizumab in primary trabeculectomy: results at 1 year
Authors: Jurkowska‐Dudzińska Justyna , Kosior‐Jarecka Ewa , Żarnowski Tomasz
Published: June 2011

Abstract

Background:  The present study compared the effects of adjuvant bevacizumab and 5‐fluorouracil on the efficacy and safety of trabeculectomy.

Design:  A nonrandomized, prospective, interventional case study.

Participants:  A total of 62 patients in two groups undergoing primary trabeculectomy.

Methods:  In Group 1 (21 primary open‐angle glaucoma, nine pseudoexfoliative glaucoma), trabeculectomy was performed with an adjuvant 5% solution of 5‐fluorouracil administered for 4 min, intraoperatively. In Group 2 (21 primary open‐angle glaucoma, 11 pseudoexfoliative glaucoma), trabeculectomy was enhanced with 1.25 mg of bevacizumab applied subconjunctivally immediately before and after surgery and again 1 and 7 days after surgery.

Main Outcome Measures:  Intraocular pressure, best corrected visual acuity, visual field index, bleb morphology, cornel endothelial cell count.

Results:  Mean intraocular pressure was 28.0 ± 8.0 mmHg before 5‐fluorouracil‐augmented trabeculectomy and 27.8 ± 9.5 mmHg before bevacizumab‐augmented trabeculectomy. After 12 months, mean intraocular pressure was 13.6 ± 4.4 mmHg in the 5‐fluorouracil group and 14.7 ± 4.7 mmHg in the bevacizumab group. A 30% reduction of initial intraocular pressure was attained in 86.7% of patients in the 5‐fluorouracil group and 78.1% of patients in the bevacizumab group at the end of follow up. No significant differences were noted between the two studied groups with respect to corneal endothelial density, visual field indices and postoperative complications.

Conclusions:  The 12‐month intraocular pressure results showed no significant differences between the two groups of patients after bevacizumab or 5‐fluorouracil to augment trabeculectomy. However, to obtain successful intraocular pressure control more patients in bevacizumab group needed medical therapy.
Probing basal ganglia functions by saccade eye movements
Authors: Watanabe Masayuki , Munoz Douglas P.
Published: June 2011

The basal ganglia (BG) are a group of subcortical structures involved in diverse functions, such as motor, cognition and emotion. However, the BG do not control these functions directly, but rather modulate functional processes occurring in structures outside the BG. The BG form multiple functional loops, each of which controls different functions with similar architectures. Accordingly, to understand the modulatory role of the BG, it is strategic to uncover the mechanisms of signal processing within specific functional loops that control simple neural circuits outside the BG, and then extend the knowledge to other BG loops. The saccade control system is one of the best‐understood neural circuits in the brain. Furthermore, sophisticated saccade paradigms have been used extensively in clinical research in patients with BG disorders as well as in basic research in behaving monkeys. In this review, we describe recent advances of BG research from the viewpoint of saccade control. Specifically, we account for experimental results from neuroimaging and clinical studies in humans based on the updated knowledge of BG functions derived from neurophysiological experiments in behaving monkeys by taking advantage of homologies in saccade behavior. It has become clear that the traditional BG network model for saccade control is too limited to account for recent evidence emerging from the roles of subcortical nuclei not incorporated in the model. Here, we extend the traditional model and propose a new hypothetical framework to facilitate clinical and basic BG research and dialogue in the future.
The neural control of fast vs. slow vergence eye movements
Authors: Cullen Kathleen E. , Van Horn Marion R.
Published: June 2011

When looking between targets located in three‐dimensional space, information about relative depth is sent from the visual cortex to the motor control centers in the brainstem, which are responsible for generating appropriate motor commands to move the eyes. Surprisingly, how the neurons in the brainstem use the depth information supplied by the visual cortex to precisely aim each eye on a visual target remains highly controversial. This review will consider the results of recent studies that have focused on determining how individual neurons contribute to realigning gaze when we look between objects located at different depths. In particular, the results of new experiments provide compelling evidence that the majority of saccadic neurons dynamically encode the movement of an individual eye, and show that the time‐varying discharge of the saccadic neuron population encodes the drive required to account for vergence facilitation during disconjugate saccades. Notably, these results suggest that an additional input (i.e. from a separate vergence subsystem) is not required to shape the activity of motoneurons during disconjugate saccades. Furthermore, whereas motoneurons drive both fast and slow vergence movements, saccadic neurons discharge only during fast vergence movements, emphasizing the existence of distinct premotor pathways for controlling fast vs. slow vergence. Taken together, these recent findings contradict the traditional view that the brain is circuited with independent pathways for conjugate and vergence control, and thus provide an important new insight into how the brain controls three‐dimensional gaze shifts.
Mechanisms for generating and compensating for the smallest possible saccades
Authors: Hafed Ziad M.
Published: June 2011

Microsaccades are small eye movements that occur during gaze fixation. Although taking place only when we attempt to stabilize gaze position, microsaccades can be understood by relating them to the larger voluntary saccades, which abruptly shift gaze position. Starting from this approach to microsaccade analysis, I show how it can lead to significant insight about the generation and functional role of these eye movements. Like larger saccades, microsaccades are now known to be generated by brainstem structures involved not only in compiling motor commands for eye movements, but also in identifying and selecting salient target locations in the visual environment. In addition, these small eye movements both influence and are influenced by sensory and cognitive processes in various areas of the brain, and in a manner that is similar to the interactions between larger saccades and sensory or cognitive processes. By approaching the study of microsaccades from the perspective of what has been learned about their larger counterparts, we are now in a position to make greater strides in our understanding of the function of the smallest possible saccadic eye movements.
Binocular coordination of eye movements – Hering’s Law of equal innervation or uniocular control?
Authors: King W. M.
Published: June 2011

The neurophysiological basis for binocular control of eye movements in primates has been characterized by a scientific controversy that has its origin in the historical conflict of Hering and Helmholtz in the 19th century. This review focuses on two hypotheses, linked to that conflict, that seek to account for binocular coordination – Hering’s Law vs. uniocular control of each eye. In an effort to manage the length of the review, the focus is on extracellular single‐unit studies of premotor eye movement cells and extraocular motoneurons. In the latter half of the 20th century, these studies provided a wealth of neurophysiological data pertaining to the control of vergence and conjugate eye movements. The data were initially supportive of Hering’s Law. More recent data, however, have provided support for uniocular control of each eye consistent with Helmholtz’s original idea. The controversy is far from resolved. New anatomical descriptions of the disparate inputs to multiply and singly innervated extraocular muscle fibers challenge the concept of a ‘final common pathway’ as they suggest there may be separate groups of motoneurons involved in vergence and conjugate control of eye position. These data provide a new challenge for interpretation of uniocular premotor control networks and how they cooperate to produce coordinated eye movements.
Cortico‐basal ganglia mechanisms for overcoming innate, habitual and motivational behaviors
Authors: Isoda Masaki , Hikosaka Okihide
Published: June 2011

Most of the human behaviors are executed automatically under familiar circumstances. These behaviors are prepotent in that they take precedence over any other potential alternatives. Yet, humans are also capable of engaging cognitive resources to inhibit such a prepotent behavior and replace it with an alternative controlled behavior in response to an unforeseen situation. This remarkable capability to switch behaviors in a short period of time is the hallmark of executive functions. In this article, we first argue that the prepotent automaticity could emerge at least in three different domains – innate, habitual and motivational. We then review neurophysiological findings on how the brain might realize its switching functions in each domain, primarily by focusing on the monkey oculomotor system as the experimental model. Emerging evidence now suggests that multiple neuronal populations in the shared cortico‐basal ganglia network contribute to overriding prepotent eye movement, be its origin innate, habitual or motivational. This consideration suggests the general versatility of the cortico‐basal ganglia network as the neural mechanism whereby humans and other animals keep themselves from becoming subservient to reflex, habit and motivational impulses.
Contribution of the central thalamus to the generation of volitional saccades
Authors: Tanaka Masaki , Kunimatsu Jun
Published: June 2011

Lesions in the motor thalamus can cause deficits in somatic movements. However, the involvement of the thalamus in the generation of eye movements has only recently been elucidated. In this article, we review recent advances into the role of the thalamus in eye movements. Anatomically, the anterior group of the intralaminar nuclei and paralaminar portion of the ventrolateral, ventroanterior and mediodorsal nuclei of the thalamus send massive projections to the frontal eye field and supplementary eye field. In addition, these parts of the thalamus, collectively known as the ‘oculomotor thalamus’, receive inputs from the cerebellum, the basal ganglia and virtually all stages of the saccade‐generating pathways in the brainstem. In their pioneering work in the 1980s, Schlag and Schlag‐Rey found a variety of eye movement‐related neurons in the oculomotor thalamus, and proposed that this region might constitute a ‘central controller’ playing a role in monitoring eye movements and generating self‐paced saccades. This hypothesis has been evaluated by recent experiments in non‐human primates and by clinical observations of subjects with thalamic lesions. In addition, several recent studies have also addressed the involvement of the oculomotor thalamus in the generation of anti‐saccades and the selection of targets for saccades. These studies have revealed the impact of subcortical signals on the higher‐order cortical processing underlying saccades, and suggest the possibility of future studies using the oculomotor system as a model to explore the neural mechanisms of global cortico‐subcortical loops and the neural basis of a local network between the thalamus and cortex.
The role of the lateral intraparietal area in orienting attention and its implications for visual search
Authors: Bisley James W. , Mirpour Koorosh , Arcizet Fabrice , Ong Wei S.
Published: June 2011

Orienting visual attention is of fundamental importance when viewing a visual scene. One of the areas thought to play a role in the guidance of this process is the posterior parietal cortex. In this review, we will describe the way the lateral intraparietal area (LIP) of the posterior parietal cortex acts as a priority map to help guide the allocation of covert attention and eye movements (overt attention). We will explain the concept of a priority map and then show that LIP activity is biased by both bottom‐up stimulus‐driven factors and top‐down cognitive influences, and that this activity can be used to predict the locus of covert attention and initial saccadic latencies in simple visual search tasks. We will then describe evidence for how this system acts during covert visual search and how its activity could be used to optimize overt visual search performance.
Parietofrontal circuits in goal‐oriented behaviour
Authors: Medendorp W. Pieter , Buchholz Verena N. , Van Der Werf Jurrian , Leoné Frank T. M.
Published: June 2011

Parietal and frontal cortical areas play important roles in the control of goal‐oriented behaviour. This review examines how signal processing in the parietal and frontal eye fields is involved in coding and storing space, directing attention and processing the sensorimotor transformation for saccades. After a survey of the functional specialization of these areas in monkeys, we discuss homologous regions in the human brain in terms of topographic organization, storage capacity, target selection, spatial remapping, reference frame transformations and effector specificity. The overall picture suggests that bottom‐up sensory, top‐down cognitive signals and efferent motor signals are integrated in dynamic sensorimotor maps as part of a functionally flexible parietofrontal network. Neuronal synchronization in these maps may be instrumental in amplifying behaviourally relevant representations and setting up a functional pathway to route information in this parietofrontal circuit.
Tonic and phasic components of eye movements during REM sleep in the rat
Authors: Sánchez‐López Alvaro , Escudero Miguel
Published: June 2011

Phasic oculomotor activity is one of the features identifying rapid eye movement (REM) sleep. Recently, it has been shown in cats that, despite bursts of complex two‐component rapid eye movements, the eyes tend to maintain a nasal and downward rotation during REM sleep. Although the function of eye movements during sleep remains elusive, it is important to know whether the characteristics of eye movements during sleep are species‐specific in mammals. In this work, quantitative characteristics of eye movements, recorded by the scleral search coil technique, were studied during wakefulness and sleep in rats. During wakefulness, rats performed conjugated saccades at a very low rate and some eye movements associated to blinking and gnawing. Throughout non‐REM sleep, eye movements were slow, mostly unconjugated and the eyes maintained a divergence in the horizontal plane. The beginning of REM sleep was characterized by a convergence and downward rotation of the eyes, which tended to persist until the end of REM sleep. Rapid eye movements, isolated and monocular at the beginning, became complex and organized in high‐frequency bursts. These results demonstrate that, despite the difference in extraocular anatomy and visuomotor strategies between frontal‐ and lateral‐eyed species, eye movements during REM sleep in rats are very similar to those described in cats. This suggests that the mechanisms generating eye movements during REM sleep are largely conserved in mammals.
The relationship between spatial attention and saccades in the frontoparietal network of the monkey
Authors: Wardak Claire , Olivier Etienne , Duhamel Jean‐René
Published: June 2011

Spatial attention bears a remarkable resemblance to saccadic eye movements from both a behavioural and a neurophysiological point of view. In this review, we examine the contributions of two cortical areas, namely the lateral intraparietal area (LIP) and frontal eye field (FEF), to saccades and attention and discuss the possible interactions between these two areas. Based on the results of electrophysiological studies and on inactivation studies performed in the macaque monkey, we propose that LIP is mainly involved in salience representation and an attentional selection mechanism that underlies saccade guidance, at least when two objects or locations are in competition in the visual environment. In contrast, we suggest that FEF is involved in coding and triggering saccadic eye movements, as well as in coding the location of attention or the attentional shifts. However, these two functions subserved by the FEF are dissociable at a neuronal level. Saccade planning and attentional selection are intimately coupled from a behavioural point of view but correspond to distinct functional operations.
Neck muscle responses evoked by transcranial magnetic stimulation of the human frontal eye fields
Authors: Goonetilleke Samanthi C. , Gribble Paul L. , Mirsattari Seyed M. , Doherty Timothy J. , Corneil Brian D.
Published: June 2011

Transcranial magnetic stimulation (TMS) provides a non‐invasive means of investigating brain function. Whereas TMS of the human frontal eye fields (FEFs) does not induce saccades, electrical stimulation of the monkey FEF evokes eye–head gaze shifts, with neck muscle responses evoked at stimulation levels insufficient to evoke a saccade. These animal results motivated us to examine whether TMS of the FEF (TMS‐FEF) in humans evokes a neck muscle response. Subjects performed memory‐guided saccades to the left or right while TMS (two pulses at 20 Hz) was delivered on 30% of trials to the left FEF coincident with saccade instruction. As reported previously, TMS‐FEF decreased contralateral saccade reaction times. We simultaneously recorded the activity of splenius capitis (SPL) (an ipsilateral head turner). TMS‐FEF evoked a lateralized increase in the activity of the right SPL but not the left SPL, consistent with the recruitment of a contralateral head‐turning synergy. In some subjects, the evoked neck muscle response was time‐locked to stimulation, whereas in others the evoked response occurred around the time of the saccade. Importantly, evoked responses were greater when TMS was applied to the FEF engaged in contralateral saccade preparation, with even greater evoked responses preceding shorter latency saccades. These results provide new insights into both the nature of TMS and the human oculomotor system, demonstrating that TMS‐FEF engages brainstem oculomotor circuits in a manner consistent with a general role in eye–head gaze orienting. Our results also suggest that pairing neck muscle recordings with TMS‐FEF provides a novel way of assaying the covert preparation of oculomotor plans.
Neural mechanisms of saccade target selection: gated accumulator model of the visual–motor cascade
Authors: Schall Jeffrey D. , Purcell Braden A. , Heitz Richard P. , Logan Gordon D. , Palmeri Thomas J.
Published: June 2011

We review a new computational model developed to understand how evidence about stimulus salience in visual search is translated into a saccade command. The model uses the activity of visually responsive neurons in the frontal eye field as evidence for stimulus salience that is accumulated in a network of stochastic accumulators to produce accurate and timely saccades. We discovered that only when the input to the accumulation process was gated could the model account for the variability in search performance and predict the dynamics of movement neuron discharge rates. This union of cognitive modeling and neurophysiology indicates how the visual–motor transformation can occur, and provides a concrete mapping between neuron function and specific cognitive processes.
The search for the neural mechanisms of the set size effect
Authors: Jerde Trenton A. , Ikkai Akiko , Curtis Clayton E.
Published: June 2011

The set size effect in visual search refers to the linear increase in response time (RT) or decrease in accuracy as the number of distractors increases. Previous human and monkey studies have reported a correlation between set size and neural activity in the frontal eye field (FEF) and intraparietal sulcus (IPS). In a recent functional magnetic resonance imaging study, we did not observe a set size effect in the superior precentral sulcus (sPCS, thought to be the human homolog of the FEF) and IPS in an oculomotor visual search task (Ikkai et al., 2011). Our task used placeholders in the search array, along with the target and distractors, in order to equate the amount of retinal stimulation for each set size. We here attempted to reconcile these differences with the results from a follow‐up experiment in which the same oculomotor visual search task was used, but without placeholders. A strong behavioral set size effect was observed in both studies, with very similar saccadic RTs and slopes between RT and set size. However, a set size effect was now observed in the sPCS and IPS. We comment on this finding and discuss the role of these neural areas in visual search.
Split of spatial attention as predicted by a systems‐level model of visual attention
Authors: Zirnsak Marc , Beuth Frederik , Hamker Fred H.
Published: June 2011

Can we attend to multiple distinct spatial locations at the same time? According to a recent psychophysical study [J. Dubois et al. (2009)Journal of Vision, 9, 3.1–11] such a split of spatial attention might be limited to short periods of time. Following N. P. Bichot et al. [(1999)Perception & Psychophysics, 61, 403–423] subjects had to report the identity of multiple letters that were briefly presented at different locations, while two of these locations (targets) were relevant for a concurrent shape comparison task. In addition to the design used by Bichot et al. stimulus onset asynchrony between shape onset and letters was systematically varied. In general, the performance of subjects was superior at target locations. Furthermore, for short stimulus onset asynchronies, performance was simultaneously increasing at both target locations. For longer stimulus onset asynchronies, however, performance deteriorated at one of the target locations while increasing at the other target location. It was hypothesized that this dynamic deployment of attention might be caused by competitive processes in saccade‐related structures such as the frontal eye field. Here we simulated the task of Dubois et al. using a systems‐level model of attention. Our results are consistent with recent findings in the frontal eye field obtained during covert visual search, and they support the view of a transient deployment of spatial attention to multiple stimuli in the early epoch of target selection.
Investigating the role of the superior colliculus in active vision with the visual search paradigm
Authors: Shen Kelly , Valero Jerome , Day Gregory S. , Paré Martin
Published: June 2011

We review here both the evidence that the functional visuomotor organization of the optic tectum is conserved in the primate superior colliculus (SC) and the evidence for the linking proposition that SC discriminating activity instantiates saccade target selection. We also present new data in response to questions that arose from recent SC visual search studies. First, we observed that SC discriminating activity predicts saccade initiation when monkeys perform an unconstrained search for a target defined by either a single visual feature or a conjunction of two features. Quantitative differences between the results in these two search tasks suggest, however, that SC discriminating activity does not only reflect saccade programming. This finding concurs with visual search studies conducted in posterior parietal cortex and the idea that, during natural active vision, visual attention is shifted concomitantly with saccade programming. Second, the analysis of a large neuronal sample recorded during feature search revealed that visual neurons in the superficial layers do possess discriminating activity. In addition, the hypotheses that there are distinct types of SC neurons in the deeper layers and that they are differently involved in saccade target selection were not substantiated. Third, we found that the discriminating quality of single‐neuron activity substantially surpasses the ability of the monkeys to discriminate the target from distracters, raising the possibility that saccade target selection is a noisy process. We discuss these new findings in light of the visual search literature and the view that the SC is a visual salience map for orienting eye movements.
Full reaction time distributions reveal the complexity of neural decision‐making
Authors: Noorani Imran , Carpenter R. H. S.
Published: June 2011

Measurement of the stochastic distribution of reaction time or latency has become a popular technique that can potentially provide precise, quantitative information about the underlying neural decision mechanisms. However, this approach typically requires data from large numbers of individual trials, in order to enable reliable distinctions to be made between different models of decision. When data are not plentiful, an approximation to full distributional information can be provided by using a small number of quantiles instead of full distributions – often, just five are used. Although this can often be adequate when the proposed underlying model is a relatively simple one, we show here that, with more complex tasks, and correspondingly extended models, this kind of approximation can often be extremely misleading, and may hide important features of the underlying mechanisms that only full distributional analysis can reveal.
Contribution of the retino‐tectal pathway to visually guided saccades after lesion of the primary visual cortex in monkeys
Authors: Kato Rikako , Takaura Kana , Ikeda Takuro , Yoshida Masatoshi , Isa Tadashi
Published: June 2011

Previous reports on ‘blindsight’ have shown that some patients with lesions of the primary visual cortex (V1) could localize visual targets in their scotoma with hand and/or eye movements without visual awareness. A role of the retino‐tectal pathway on residual vision has been proposed but the direct evidence for this still remains sparse. To examine this possibility, we inactivated the superior colliculus (SC) of unilateral V1‐lesioned monkeys using microinjections of muscimol, and analysed the effects on visually guided saccades. Following muscimol injections into the contralesional SC, the monkeys performed the visually guided saccade task with relatively minor deficits. The effects of ipsilesional SC inactivation were more severe. After injections, the monkeys failed to localize the target within the visual field represented at the injection site on the SC map. The effects of ipsilesional SC inactivation may result from sensory deficits, motor deficits or a combination of both. To examine these possibilities, we tested the effects of SC inactivation on the motor system by investigating spontaneous saccades. After inactivation of the ipsilesional SC, spontaneous saccades toward the injection site were not abolished, suggesting that impairment of visually guided saccades following inactivation of the ipsilesional SC could not be explained solely by a motor deficit and was primarily due to a visual deficit, presumably by interfering with processing in the superficial layer. We conclude that the retino‐tectal pathway plays an essential role in residual vision after V1 lesion. The results suggest that this pathway may be involved in mediating unconscious vision in blindsight patients.
Emotional reactions to scandals: When does moral character make a difference?
Authors: Jiang Jiang , Kou Yu , Wang Fang , Wu Ying , Li Yan‐Mei , Li Yuan , Yang Yiyin , Cao Hui , Wu Qiuping , Jing Shi‐Jie , Jiang Bi‐Jing , Shen La‐Mei , Li Ai‐Juan , Li Zhongquan , Gao Wenjun , Chiu Chi‐Yue , Hong Ying‐Yi , Hsu Shih‐Chi , Zhang Lin , Yang Bao‐Yan , Yang Xiao‐Li , Zhao De‐Lei , Zou Zhimin , Wei Qing‐Wang , Chen Xia , Zhao Yu‐Fang , Zhou Yi‐Jin , Chen Hong , Feng Jianping , Wang Xin
Published: June 2011

A scandal can evoke public outrage when it is widely publicized and involves an individual who is perceived to have a high level of cultural representativeness. Two experiments showed that when the scandalous target's moral character was highlighted, emotional responses towards the target were least negative when the scandal was widely circulated and when the target was seen as a representative of his culture. These results suggest that when a cultural symbol is implicated in a widely‐circulated scandal, the negative emotions directed towards the scandalous individual can be alleviated when the public remains confident in his or her commitment to morality.
Identifying Discontinuities in Trend Surfaces Using Bilateral Kernel Regression
Authors: Brunsdon Chris
Published: June 2011

Following a brief review of the kernel regression approach to estimating surface models of the form z=f(x,y) +ε, this article will consider the situation where f is not a continuous surface function, and in particular where the discontinuities take the form of one‐dimensional breaks in the surface, and are not specified a priori. This form of model is particularly useful when visualizing some social and economic data where very rapid changes in geographical characteristics may occur – such as crime rates or house prices. The article briefly reviews approaches to this problem and proposes a novel approach (Bilateral Kernel Regression) adapting an algorithm from the field field of image processing (Bilateral Filtering), giving example analyses of synthetic and real‐world data. Techniques for enhancing the basic algorithm are also considered.
Spatially Clustered Associations in Health Related Geospatial Data
Authors: Leibovici Didier G. , Bastin Lucy , Anand Suchith , Hobona Gobe , Jackson Mike
Published: June 2011

Overlaying maps using a desktop GIS is often the first step of a multivariate spatial analysis. The potential of this operation has increased considerably as data sources and Web services to manipulate them are becoming widely available via the Internet. Standards from the OGC enable such geospatial ‘mashups’ to be seamless and user driven, involving discovery of thematic data. The user is naturally inclined to look for spatial clusters and ‘correlation’ of outcomes. Using classical cluster detection scan methods to identify multivariate associations can be problematic in this context, because of a lack of control on or knowledge about background populations. For public health and epidemiological mapping, this limiting factor can be critical but often the focus is on spatial identification of risk factors associated with health or clinical status. In this article we point out that this association itself can ensure some control on underlying populations, and develop an exploratory scan statistic framework for multivariate associations. Inference using statistical map methodologies can be used to test the clustered associations. The approach is illustrated with a hypothetical data example and an epidemiological study on community MRSA. Scenarios of potential use for online mashups are introduced but full implementation is left for further research.
Location Intelligence: An Innovative Approach to Business Location Decision‐making
Authors: Weber Patrick , Chapman Dave
Published: June 2011

As one of the leading ‘world cities’, London is particularly reliant on sources of foreign direct investment (FDI). In the face of increasing global competition and a difficult economic climate, the capital must compete effectively to encourage and support such investors. Through a collaborative study with London's official FDI promotion agency, Think London, the need for a coherent framework for data, methodologies and tools to inform business location decision‐making became apparent. This article discusses the development of a rich environment to explore, compare and rank London's business neighbourhoods. This is achieved through the development and evaluation of a model for location‐based decision support. First, we discuss the development of a geo‐business classification for London which draws upon methods and practices common in geodemographic neighbourhood classification. A geo‐business classification is developed, encapsulating relevant location variables using Principal Components Analysis into a set of composite area profiles. Second, we discuss the implementation of an appropriate Multi‐Criteria Decision Making methodology, in this case Analytical Hierarchy Process (AHP), enabling the aggregation of the geo‐business classification and decision‐makers' preferences into discrete decision alternatives. Finally, we present the results of the integration of both data and model through the development and evaluation of a web‐based prototype.
Exploring the Historical Determinants of Urban Growth Patterns through Cellular Automata
Authors: Stanilov Kiril , Batty Michael
Published: June 2011

We have adapted METRONAMICA, an established cellular automata (CA) modelling system, to simulate the historical growth of a section of a large world city. Our model is tuned to reflect the morphology of land use patterns more accurately than traditional CA models, which abstract those patterns to more aggregate spatial scales. We explore the spatial determinants of land use patterns with detailed empirical data, documenting the historical growth of West London at an unusually high level of spatial and temporal resolution. The results of the study provide support for our considered speculations: (1) that the spatial relationships between land uses and the physical environment are remarkably consistent through time, showing little variation relative to changes in historical context; and (2) that these relationships constitute a basic code for urban growth which determines the spatial signature of land development in a given metropolitan area.
Street‐level Spatial Scan Statistic and STAC for Analysing Street Crime Concentrations
Authors: Shiode Shino
Published: June 2011

This study develops new types of hotspot detection methods to describe the micro‐space variation of the locations of crime incidents at the street level. It expands on two of the most widely used hotspot detection methods, Spatial and Temporal Analysis of Crime and Spatial Scan Statistic, and applies them to the analysis of the network space. The study first describes the conceptual and the methodological framework of the new methods followed by analyses using: (1) a simulated distribution of points along the street network; and (2) real street‐crime incident data. The simulation study using simulated point distributions confirms that the proposed methods is more accurate, stable and sensitive in detecting street‐level hotspots than their conventional counterparts are. The empirical analysis with real crime data focuses on the distribution of the drug markets and robberies in downtown Buffalo, NY in 1995 and 1996. The drug markets are found to form hotspots that are dense, compact and stable whereas hotspots of the robberies are observed more thinly across a wider area. The study also reveals that the location of the highest risk remains on the same spot over time for both types of crimes, indicating the presence of hotbeds which requires further attention.
How fast is a cow? Cross‐Scale Analysis of Movement Data
Authors: Laube Patrick , Purves Ross S.
Published: June 2011

Data representing the trajectories of moving point objects are becoming increasingly ubiquitous in GIScience, and are the focus of much methodological research aimed at extracting patterns and meaning describing the underlying phenomena. However, current research within GIScience in this area has largely ignored issues related to scale and granularity – in other words how much are the patterns that we see a function of the size of the looking glass that we apply? In this article we investigate the implications of varying the temporal scale at which three movement parameters, speed, sinuosity and turning angle are derived, and explore the relationship between this temporal scale and uncertainty in the individual data points making up a trajectory. A very rich dataset, representing the movement of 10 cows over some two days every 0.25 s is investigated. Our cross‐scale analysis shows firstly, that movement parameters for all 10 cows are broadly similar over a range of scales when the data are segmented to remove quasi‐static subtrajectories. However, by exploring realistic values of GPS uncertainty using Monte Carlo Simulation, it becomes apparent that fine scale measurement of all movement parameters is masked by uncertainties, and that we can only make meaningful statements about movement when we take these uncertainties into account.
Using Participatory Computer Simulation to Explore the Process of Urban Evolution
Authors: Dearden Joel , Wilson Alan
Published: June 2011

When planners intervene in urban systems they seek in part to generate a positive response from those parts of a city outside of their control, namely the private market and private individuals. This response is difficult to predict due to the fact that the city is a nonlinear system of organized complexity. Models of cities which seek to explain this response are necessarily complicated and dynamic. Where an analytical solution is not possible we turn to computer simulation and interactive visualization in order to understand their output. Allowing human participation in such simulations provides a sandbox in which to experiment with the dynamic behaviour of an urban model and play a part in its evolution. Two possible options for structuring this participation are: (1) toy retail systems, which allow unconstrained experimentation, and (2) games, which impose rules and involve role‐play and competition. To explore these ideas we construct a toy retail system and a two‐player retail game, both of which are derived from an existing agent‐based retail model. We explore the application of these systems to the metropolitan county of South Yorkshire in the UK.
Automatic Classification of Retail Spaces from a Large Scale Topographic Database
Authors: Mackaness William A , Chaudhry Omair Z
Published: June 2011

There is considerable interest in understanding the distribution patterns of different types of retail space, over time, and doing so at a national scale. Yet a lack of suitable data, coupled with poor classification schemas, has stymied efforts to create such a national perspective. This research reports on metrics and classification methodologies that have been applied to large scale topographic data, that afford a systematic classification of certain retail spaces potentially at the national coverage. By analysing the form, composition, extent and patterns of buildings within retail spaces, together with their degree of centrality and levels of access, we demonstrate that it is possible to classify different types of retail space. The research illustrates the utility of fine scale topographic data beyond mere mapping. The article compares three methodologies used for classification (Boolean, fuzzy logic and Bayesian modelling) and evaluates them through comparison with known locations of various retail types as a way of assessing the validity of these approaches. The quality of the results are good, though the work highlights the inconsistency in definitions that currently exist – reflecting, as much as anything, the shifting sands of definitions of various retail spaces that ebb and flow according to consumer needs, and the ambitions of urban planners.
A Comparison of Fuzzy AHP and Ideal Point Methods for Evaluating Land Suitability
Authors: Elaalem Mukhtar , Comber Alexis , Fisher Pete
Published: June 2011

This article compares two fuzzy approaches to land suitability evaluations, Analytical Hierarchy Process (AHP) and Ideal Point. The methods were evaluated using a case study which models the opportunities for wheat production under irrigation conditions in the north‐western region of Jeffara Plain, Libya. A number of relevant soil and landscape criteria were identified through a review of the literature and their weights specified as a result of discussions with local experts. The results of the Fuzzy AHP showed that the majority of the study area has membership values to the set of suitability between 0.40 and 0.50, while the results of the Ideal Point approach revealed most of the study area to have membership values between 0.30 and 0.40. While the Fuzzy AHP and Ideal Point approaches accommodate the continuous nature of many soil properties and produce more intuitive distributions of land suitabilities values, the Fuzzy AHP approach was found to be better than Fuzzy Ideal Point. This was due to the latter's tendency to be biased towards positive and negative ideal values.