Sensory processing, perception and communication in simple nervous systems

我的研究计划试图将对自然行为及其适应性约束的研究与对潜在神经机制的分析结合起来，以解决以下领域的基本和实际问题。A.在感觉定向任务中整合线索的共同原则。B.感官知觉的简单模型。C.交流中感觉生态和信号复杂性之间的关系。本提案的具体目标： 1.昆虫听觉加工。1A.寄生蝇(Ormiasp.)通过定位雄蟋蟀的歌声来找到主人，并以无与伦比的准确性定向听力。目前的工作解决了该系统中听力的新维度，包括可塑性、仰角敏感性(3D定位)和幼虫背景下的近场听力(远程趋音之后的一种独特的行为背景)。1B.刺激识别中的可塑性和群体分化。地理上不同的奥米亚种群利用当地特定的寄主物种，这些寄主物种在与寄主识别和发声有关的歌曲特征上存在差异。信号偏好的定量测量允许跨种群的标准化比较来量化寄主特定的差异。对三个种群(FL、TX、CA)的实地工作正在扩大这些比较研究的范围，以包括可能导致苍蝇种群之间寄主觅食策略差异的生态变量(捕食；寄主密度)。 2.振动感官信号。蜘蛛对振动刺激的编码、识别和定位的细节主要是从对少数物种的研究中得知的。蚕丝的纤网结构和材料性能有很大的变化，人们对这些因素与振动刺激的传播和处理之间的关系越来越感兴趣。关于蜘蛛网栖息的寡妇蜘蛛的拟议工作将检查蛛网和丝绸的机械特性；表征振动信号和线索(猎物和同种蜘蛛)，并将这些与信号传播中作为蛛网特性函数的变化联系起来。 3.通信和信号复杂性的演变。3A.竞争信号。这项工作的重点是信号成本在沟通和竞争中的作用，使用直翅目昆虫和跳跃蜘蛛。我将通过将能量消耗的测量(呼吸测量)与竞争成功和信号质量(昆虫的声音信号；蜘蛛的振动信号)的个体差异联系起来，继续进行信号代谢成本方面的工作。3B.振动信号结构。目前对寡妇蜘蛛的研究记录了在单个显示序列中从随机信号到结构化信号的过程。因此，它们是测试信号组织功能重要性的一个很好的模型。拟议的工作将把这些行为研究与振动感觉工作(2)结合起来，对振动信号的感觉生态(从物理约束到感觉编码，再到行为)进行综合研究。

My research program seeks to integrate studies of natural behaviour and its adaptive constraints with analyses of underlying neural mechanism to address fundamental and practical questions in the following areas. A. Common principles for integration of cues in sensory orientation tasks. B. Simple models of sensory perception. C. Relationship between sensory ecology and signal complexity in communication. Specific objectives for this proposal: 1. Insect auditory processing. 1a. Parasitoid flies (Ormia sp.) find hosts by localizing the songs of male crickets with directional hearing of unsurpassed accuracy. Current work addresses novel dimensions of hearing in this system, including plasticity, elevation sensitivity (3D localization), and near-field hearing in the context of larviposition (a distinct behavioural context following long-range phonotaxis). 1b. Plasticity and population divergence in stimulus recognition. Geographically distinct Ormia populations exploit locally specific host species varying in song characteristics relevant to host recognition and phonotaxis. A quantitative measure of signal preference allows standardized comparisons across populations to quantify host-specific divergence. Field work on three populations (FL, TX, CA) is extending these comparative studies to include ecological variables (predation; host density) that may contribute to divergence of host-foraging strategies among fly populations. 2. Vibrational sensory signals. Details of coding, recognition, and localisation of vibration stimuli by spiders are primarily known from work on few species. There is considerable variation in the structure of webs and material properties of silk, and growing interest in the relationship between these factors and the propagation and processing of vibration stimuli. Proposed work on cobweb-dwelling widow spiders will examine mechanical properties of webs and silk; characterise vibration signals and cues (prey vs conspecifics) and link these to variation in signal propagation as a function of web properties. 3. Evolution of communication and signal complexity. 3a. Competitive signals. This work is focused the role of signal costs in communication and competition, using the orthopteran insects and jumping spiders. I will continue on-going work on metabolic costs of signalling by correlating measures of energy consumption (respirometry) with individual variation in competitive success and signal quality (acoustic signals in insects; vibratory signals in spiders). 3b. Vibrational signal structure. Current work on widow spiders documents a progression from haphazard to structured signals within a single display sequence. They are therefore a good model for testing the functional significance of signal organization. Proposed work will integrate these behavioural studies with vibrosensory work (2) for an integrative study of the sensory ecology of vibrational signals (from physical constraints, to sensory coding, to behaviour).