目标和干扰子之间的拓扑性质差异可以削弱拥挤效应

\"拥挤效应\"被认为是外周视觉物体辨认过程中的一个重要瓶颈.它是指当目标被干扰子包围,在外周视野呈现时,观察者辨认目标的能力被大大削弱,尤其是当目标和干扰子之间存在某种相似性时.许多研究分别试图在不同层次上提出解释这一现象的机制.本文通过三个实验,使用了不同的视觉刺激图形的辨认任务(例如,三角形和箭头的朝向判断、数字和字母的辨认以及S形图形的朝向辨认),测量了目标和干扰子之间中心距离的阈值,结果一致地发现,当目标和干扰子之间存在拓扑性质差异(洞的个数差异)时,拥挤效应会显著降低,并且排除了目标和干扰子之间的主观相似性、形状和面积差异等可能的因素.从知觉组织的角度验证了当目标和干扰子之间存在拓扑性质差异时,拥挤效应会显著降低,这是首次发现的一个影响拥挤效应的新的维度.本文结果不仅为拥挤效应的机制提供了一个新的解释,也为大范围首先拓扑知觉在知觉物体形成中的作用提供了支持性证据.     

拓扑不变性质在运动诱发视盲现象中的作用

知觉物体的定义是认知科学领域富有争议的中心问题之一．本研究通过运动诱发视盲(MIB)现象的研究发现：a．两个图形当它们是连通的,或位于同一个洞中,或是具有相同的洞的个数,更倾向于整体共同消失或重现;b．前景图形和背景图形的拓扑性质差异,较之非拓扑性质差异,显著地削弱MIB现象;c．相对于其他各种几何性质的变化,拓扑性质的变化能更快地被知觉到返回意识状态．这些结果揭示了拓扑性质定义的知觉物体是MIB过程操作的基本单元,提示了拓扑性质改变产生新知觉物体的表征可能是意识下的过程,进一步支持了知觉物体的拓扑学定义．     

长期注射吗啡对戒断后小鼠Y－迷宫空间识别记忆的影响

使用急性成瘾性药物会影响大脑功能,随着药物使用时间的延长,这种影响更加广泛、持久,并且在药物戒断后的很长时间内依然存在。实验表明,急性及短期吗啡给予小鼠和戒断均损伤了其Y迷宫空间识别记忆能力,但这种损伤短暂且可逆。本实验小鼠被连续注射吗啡（40 mg/kg•day,i p）或生理盐水21天,利用Y迷宫来检测长期吗啡给予后在戒断第2、9和19天,吗啡对小鼠空间识别记忆的影响。结果表明, 连续吗啡给予21天后,在戒断第2、9和19天,小鼠Y迷宫空识别记忆能力均受到损伤,提示长期给予小鼠吗啡会导致其空间识别记忆能力的长期损伤。     

自闭症谱系障碍儿童拓扑变化捕获注意的缺陷

目的 自闭症谱系障碍（ASD）是一种神经发育疾病,其核心特征是交流和社会互动困难,限制性和重复行为。以往研究表明,ASD患者表现出早期和终身的注意力缺陷,这些缺陷与ASD的核心症状密切相关。基本的视觉注意加工可能为其社会交流和互动能力提供关键的基础。因此,本研究探索了ASD儿童对拓扑性质变化捕获注意的行为。方法 招募27名由专业医生根据美国精神障碍诊断与统计手册第5版（DSM-5）诊断的ASD儿童和28名年龄匹配的正常发展（TD）对照儿童。在一项注意捕获任务中,记录ASD儿童和TD儿童对拓扑变化和非拓扑变化刺激的眼跳行为。眼跳反应时（SRT）、视觉搜索时间（VS）和首次注视停留时间（FFDT）被用作注意偏向的指标。本研究还进行了注意偏向与临床评估量表之间的皮尔逊相关性检验。结果 与非拓扑变化刺激相比,TD儿童对拓扑变化刺激有更快的SRT（P0.05）和VS （P0.05）,而ASD儿童在两种指标上均没有表现出显著性差异（P0.05）。此外,ASD儿童对拓扑变化目标的注意力（由FFDT测得）显著少于TD儿童（P0.05）。而且,ASD儿童的注意偏向（由VS测得）与其强迫行为分量表得分之间存在显著负相关（P0.05）。结论 在变化检测过程中ASD儿童难以将注意转移到发生拓扑变化的物体上。这种非典型注意可能影响儿童的认知和行为发展,从而影响其社会沟通和互动。本研究表明,对拓扑变化刺激捕获注意的缺陷可能是自闭症儿童注意缺陷的一个关键特征。     

拓扑差异物体的构型处理：一项脑电研究

根据陈霖的拓扑知觉理论,在视觉感知中,拓扑差异的检测要快于局部特征的检测.本研究组认为,这一现象可能是对有＂洞＂图形和无＂洞＂图形的感知差异所造成的.本文旨在检验这两类图形所存在的知觉差异究竟是什么.利用脑电（ERP）技术,测量＂洞＂和＂非洞＂图形所引起的视觉诱发电位（VEP）,探究＂洞＂和＂非洞＂的区别.两类图形引起的VEP区别体现在N170上,＂洞＂图形的反转使得N170的潜伏期显著变化,而＂非洞＂图形的反转不会引起N170潜伏期的变化.人脸与非人脸物体的反转引起的N170变化与本结果相似.本研究认为,对＂洞＂的感知更偏向于整体加工,而对于＂非洞＂则更偏向于特征加工.     

\"大范围优先\"对象形成的神经关联:前颞叶

知觉对象是什么?这事看起来很简单,却是认知科学许多领域中最核心的问题,目前为止还没有公认的解答.\"大范围优先\"的拓扑学方法把知觉对象的定义严格地联系到拓扑变换下的不变量.知觉对象的直观概念-形状改变时其整体一致性得以保持-可以精确地被拓扑不变量,如连接组分和洞,所刻画.知觉对象的拓扑学定义已经被大量的行为学实验所验证.这些实验一致表明,虽然对象的一致性能够在非拓扑变换下得以保持,却会被拓扑变换所破坏,从而一个新的对象被感知到.特别是进一步的功能磁共振成像实验揭示,前颞页区参与拓扑知觉和知觉对象的形成,而这一脑区本来是形式视觉通路的终点.行为学上\"大范围优先\"的结果与视觉通路神经解剖学结果的悖逆,提示我们应该注意对象表征形成的问题和更广泛的意义上,知觉到底在何处发生的基本问题.     

“大范围优先”对象形成的神经关联：前颞叶

知觉对象是什么？这事看起来很简单,却是认知科学许多领域中最核心的问题,日前为止还没有公认的解答。“大范围优先”的拓扑学方法把知觉对象的定义严格地联系到拓扑变换下的不变量。知觉对象的直观概念—形状改变时其整体一致性得以保持一可以精确地被拓扑不变量,如连接组分和洞,所刻画。知觉对象的拓扑学定义已经被大量的行为学实验所验证。这些实验一致表明,虽然对象的一致性能够在非拓扑变换下得以保持,却会被拓扑变换所破坏,从而一个新的对象被感知到。特别是进一步的功能磁共振成像实验揭示,前颞页区参与拓扑知觉和知觉对象的形成,而这一脑区本来是形式视觉通路的终点。行为学上“大范围优先”的结果与视觉通路神经解剖学结果的悖逆,提示我们应该注意对象表征形成的问题和更广泛的意义上,知觉到底在何处发生的基本问题。     

BALB/c和ICR小鼠的学习记忆能力等行为学研究

目的研究不同品系小鼠学习记忆能力的差异,为学习记忆的基础研究提供应用信息。方法80只BALB/c和80只ICR小鼠分别分为Morris水迷宫组、跳台组、穿梭组、ROTA-ROD组,每组20例,进行学习记忆能力及行动能力测试。结果水迷宫组在9轮水迷宫训练学习期BALB/c小鼠空间学习记忆能力没有明显提高。ICR小鼠从9轮水迷宫训练学习期的第4次开始,逃避潜伏期显著缩短,与前3次相比差异有显著性(P<0.001)。跳台组ICR和BALB/c小鼠训练前后5 min内错误次数及跳下潜伏期差异均具有显著性。穿梭组ICR小鼠学习期与记忆期主动逃避次数、被动逃避次数及电击时间的差异均有显著性,而BALB/c小鼠训练前后主动逃避次数、被动逃避次数及电击时间的差异均无显著性。ROTA-ROD组ICR小鼠的跑步动作维持时间显著高于BALB/c小鼠,其差异有显著性。结论以上结果提示在进行某些学习记忆实验时,使用ICR小鼠优于BALB/c小鼠。     

London/Swedish双突变APP转基因小鼠的鉴定

鉴定及评价APP双突变阿尔茨海默病的转基因小鼠模型。方法将London/Swedish双突变APP基因插入到PDGF启动子下游,构建转基因表达载体,通过显微注射法建立APP695^V652I/K596N/M597L双突变转基因C57BL/6J小鼠。PCR鉴定APP695双突变转基因小鼠的基因表型,RT-PCR和Western blotting检测APP突变基因表达,免疫组化检测APP695双突变转基因小鼠大脑病理改变。水迷宫检测APP695^V652I/K596N/M597L转基因小鼠的行为学改变。结果建立了2个品系的人APP695^V652I/K596N/M597L转基因小鼠。抗Aβ1-17免疫组织化学显示APP695双突变转基因小鼠海马区阳性细胞数较APP695^V652I单突变转基因小鼠,及野生小鼠阳性细胞数明显增多,胞膜着色明显加深。双突变转基因小鼠在5月龄时可检测到老年斑。行为学检测显示APP695^V652I/K596N/M597L双突变转基因小鼠学习记忆能力比APP695^V652I单突变转基因小鼠有明显下降。结论APP695^V652I/K596N/M597L转基因小鼠较APP695^V652I转基因小鼠更早出现老年斑及学习认知能力障碍。成功建立了人APP695^V652I/K596N/M597L转基因小鼠阿尔茨海默病模型,为研究阿尔茨海默病发病机制和药物研发提供了有价值的动物模型。     

一种智能化的Y—型迷宫

本文介绍了一种智能化Ｙ－型迷宫的硬件、软件结构。它利用微机控制大鼠（或小鼠）分辨学习实验的全过程,利用红外光电传感器监测动物活动行为,判断准确,计时精确。由于以ＷＩＮＤＯＷＳ为工作平台,人机界面友好,操作简便。     

The potential of an insect pheromone lure,Z‐7‐dodecen‐1‐yl acetate,compared with peanut butter to attract laboratory and wild rats and mice

Abstract

We compared the attractiveness to rats and mice of two lures, the pheromone Z‐7‐dodecen‐1 ‐y 1 acetate and peanut butter. In the first part of the study, laboratory‐bred rats and mice were placed in a Y‐maze. Each arm of the maze offered their normal food, plus either the pheromone or 5% ethanol as a control. There were no significant differences, by species or sex, in the number of visits or the amount of time spent in each arm. The male mice took significantly less time, however, to enter the control arm of the maze than the pheromone arm. In addition, female mice were less active during the first 5 min of the Y‐maze study than during the 5 min familiarisation period, suggesting a repellent effect of the pheromone lure. In the second part of the study, tracking tunnels were placed out in the field and baited with one of three lures—the pheromone, peanut butter or a 5% ethanol control. There was no significant difference in the number of visits by mice to tunnels containing the three lures, but rats made more visits to the tunnels containing peanut butter in the “Test” stage than in the “Neo” stage. The wild rats and mice were found not to be neophobic, suggesting the standard 3‐week familiarisation period is not necessary.     

Modulation of neuropeptide Y and Y1 receptor expression in the amygdala by fluctuations in the brain content of neuroactive steroids during ethanol drinking discontinuation in Y1R/LacZ transgenic mice

Previous studies have shown that GABAergic neuroactive steroids increase Y₁ receptor (Y₁R) gene expression in the amygdala of Y ₁ R / LacZ transgenic mice, harbouring the murine Y₁R gene promoter linked to a LacZ reporter gene. As ethanol is known to increase GABAergic neuroactive steroids, we investigated the relationship between fluctuations in the brain content of neuroactive steroids induced by chronic voluntary ethanol consumption or ethanol discontinuation and both the level of neuropeptide Y (NPY) immunoreactivity and Y₁R gene expression in the amygdala of Y ₁ R / LacZ transgenic mice. Ethanol discontinuation (48 h) after voluntary consumption of consecutive solutions of 3%, 6%, 10% and 20% (v/v) ethanol over 4 weeks produced an anxiety-like behaviour as measured by elevated plus maze. Voluntary ethanol intake increased the cerebrocortical concentration of the progesterone metabolite 3α-hydroxy-5α-pregnan-20-one (3α,5α-TH PROG) that returned to control level 48 h after discontinuation of ethanol intake. Ethanol discontinuation significantly decreased NPY immunoreactivity and concomitantly increased Y ₁ R / LacZ transgene expression in the amygdala, whereas chronic ethanol intake failed to affect these parameters. The 5α-reductase inhibitor finasteride prevented both the increase in the cerebrocortical concentration of 3α,5α-TH PROG apparent after 4 weeks of ethanol intake and the changes in NPY immunoreactivity and transgene expression induced by ethanol discontinuation. Data suggest that 3α,5α-TH PROG plays an important role in the changes in NPY–Y₁R signalling in the amygdala during ethanol discontinuation.     

The choice behaviour of pigs in a Y maze: effects of deprivation of feed, social contact and bedding

We examined effects of deprivation of feed, social contact and bedding on the choice behaviour in Y maze tests. Eighty pigs were used to study two main effects: feed (estimated voluntary feed intake (VFI) vs. 70% VFI) and bedding (presence vs. absence), experiment 1; social contact (full vs. restricted) and bedding (presence vs. absence), experiment 2; and feed (as in experiment 1) and social contact (as in experiment 2), experiment 3.Overall pigs consistently chose feed and social contact over bedding. While social contact was more preferred than feed in experiment 3, there was substantial variation between pigs in their choice behaviour. The overall choice behaviour in experiment 3 contradicts previous research, but differences such as the preference methodology as well as the level of deprivation, level of reward and cost involved in accessing reward, may be responsible. Average daily weight gain (ADG) was affected in experiment 3: both feed and social restriction reduced ADG. While the feed effect is expected, one interpretation of the social effect is that social deprivation, through stress, may have reduced ADG. These results provide limited support for the notion that deprivation of a highly preferred resource may disrupt biological function.