注意促進(jìn)運(yùn)動(dòng)知覺判斷的時(shí)間進(jìn)程*

丁錦紅 汪亞珉 姜 揚(yáng)

注意促進(jìn)運(yùn)動(dòng)知覺判斷的時(shí)間進(jìn)程

丁錦紅汪亞珉姜 揚(yáng)

(北京市“學(xué)習(xí)與認(rèn)知”重點(diǎn)實(shí)驗(yàn)室, 首都師范大學(xué)心理學(xué)院, 北京 100048) (肯塔基大學(xué)醫(yī)學(xué)院行為科學(xué)系, 美國(guó) 肯塔基 40536-0086)

本研究通過控制深度視覺線索, 分析3D SFM (structure from motion)知覺中的眼動(dòng)特征, 探討注意對(duì)SFM知覺判斷的影響及其時(shí)間進(jìn)程。結(jié)果顯示, 有線索刺激比模糊刺激的判斷更加快、更加肯定(百分比更高); 眼睛移動(dòng)方向和微眼跳方向都分別與知覺判斷的運(yùn)動(dòng)方向具有一致性; 微眼跳頻次、峰速度和幅度也都分別表現(xiàn)出深度線索的促進(jìn)效應(yīng)。實(shí)驗(yàn)結(jié)果表明, SFM知覺過程大致分為速度計(jì)算和構(gòu)建三維結(jié)構(gòu)兩個(gè)階段; 注意對(duì)SFM知覺的調(diào)節(jié)作用主要發(fā)生在構(gòu)建三維結(jié)構(gòu)階段; 注意從150 ms開始指向選擇對(duì)象, 駐留持續(xù)約200 ms后, 從局部運(yùn)動(dòng)矢量流轉(zhuǎn)移到整體運(yùn)動(dòng)方向的知覺判斷。

整體運(yùn)動(dòng), 注意, 微眼跳, 時(shí)間進(jìn)程, 知覺分組

1 引言

運(yùn)動(dòng)知覺作為人類最基本的知覺形式之一, 對(duì)生存和適應(yīng)環(huán)境具有重要意義(Burr & Thompson, 2011; Nishida et al., 2018)。一直以來, 研究者們都在通過不同范式探討運(yùn)動(dòng)知覺的生理與心理機(jī)制。Wallach和O'Connell (1953)通過一系列經(jīng)典實(shí)驗(yàn)首次證明運(yùn)動(dòng)信息也可以構(gòu)建三維物體結(jié)構(gòu), 并稱之為運(yùn)動(dòng)深度效應(yīng)(kinetic depth effect或structure- from-motion, SFM)。SFM刺激是一種雙穩(wěn)態(tài)(bistable)刺激, 對(duì)它的知覺屬于整體運(yùn)動(dòng)知覺(Martínez & Parra, 2018); 嬰兒在6個(gè)月左右時(shí)已具備這種基本視覺能力(Haith, 1966; Hirshkowitz et al., 2017; Johnson et al., 2008; Lin & Tadin, 2019; Simion et al., 2008)。

1.1 SFM知覺是否受注意調(diào)節(jié)

Cavanagh (1992)將運(yùn)動(dòng)知覺區(qū)分為沒有注意參與的“低水平”自動(dòng)加工階段和受到注意調(diào)節(jié)的速度判斷階段。Nishida等(2018)進(jìn)一步提出, 在低水平加工中, 時(shí)?空頻率覺察器探測(cè)局部運(yùn)動(dòng)信號(hào), 并將這些信號(hào)整合成運(yùn)動(dòng)矢量流; 而在較高加工水平階段中, 視覺系統(tǒng)對(duì)速度地圖進(jìn)行分析與解釋。Andersen和Bradley (1998)和Treue等(1991)則將SFM知覺劃分為速度測(cè)量(低水平加工)和三維物體表面構(gòu)建(高水平加工)兩個(gè)過程。作為一種資源, 注意在運(yùn)動(dòng)知覺中的作用備受關(guān)注(Cavanagh, 1992); 它可以通過選擇來自初級(jí)視皮層的低水平運(yùn)動(dòng)信號(hào)(Hubel & Wiesel, 1962), 分別對(duì)運(yùn)動(dòng)知覺的瞬態(tài)(transient states)特征提取(Scocchia et al., 2014)、時(shí)間整合(van Rullen et al., 2005)、信息傳輸速度(Stelmach et al., 1994)、運(yùn)動(dòng)方向標(biāo)記(Ramachandran & Anstis, 1983)以及知覺解釋(Tsal & Kolbet, 1985)等方面都起到重要調(diào)節(jié)作用。同時(shí), 注意也會(huì)影響較高水平的運(yùn)動(dòng)加工(Bartlett et al., 2019)。事件相關(guān)電位(ERP)研究表明, 注意可以在不同運(yùn)動(dòng)目標(biāo)之間轉(zhuǎn)移(Franconeri & Handy, 2007; Wang et al., 2014)、探測(cè)運(yùn)動(dòng)變化(Kuldkepp et al., 2013)以及促進(jìn)深度運(yùn)動(dòng)信息整合(Lamberty et al., 2008)等。

到目前為止, 大多數(shù)研究支持注意對(duì)運(yùn)動(dòng)知覺具有促進(jìn)作用。但Motoyoshi等(2015)卻發(fā)現(xiàn), 限制注意反而可以促進(jìn)整體運(yùn)動(dòng)知覺; 即使在沒有視覺意識(shí)的情況下, 視覺系統(tǒng)依然可以完成整體運(yùn)動(dòng)加工(Chung & Khuu, 2014)。Bartlett等(2019)通過元分析也發(fā)現(xiàn), 并不是所有研究都支持注意促進(jìn)運(yùn)動(dòng)知覺的觀點(diǎn)。Bartlett等分析認(rèn)為, 由于不同水平的運(yùn)動(dòng)加工分別對(duì)應(yīng)于不同腦區(qū)的神經(jīng)活動(dòng); 高水平(如三階運(yùn)動(dòng), 區(qū)分圖形與背景)運(yùn)動(dòng)加工與注意都處于更高級(jí)大腦皮層(前額), 因而受到注意調(diào)節(jié); 而低水平(如一階運(yùn)動(dòng), 亮度等變化)運(yùn)動(dòng)加工主要在頂?枕區(qū)完成, 它是否受注意調(diào)節(jié)取決于刺激類型、運(yùn)動(dòng)速度等因素。根據(jù)SFM知覺兩階段加工觀點(diǎn)(Andersen & Bradley, 1998; Treue et al., 1991)以及注意移動(dòng)方向和選擇目標(biāo)的時(shí)間順序都是計(jì)算運(yùn)動(dòng)目標(biāo)空間關(guān)系的要素(Cavanagh et al., 2010)等, 我們推測(cè), 注意對(duì)SFM運(yùn)動(dòng)知覺的調(diào)節(jié)作用也具有階段性(時(shí)間性), 即注意對(duì)SFM運(yùn)動(dòng)知覺不同階段的調(diào)節(jié)作用存在差異。

Egeth和Yantis (1997)將視覺注意時(shí)間進(jìn)程劃分為指向(directing attention)、駐留(dwell time of attention)和移動(dòng)(movement of attention)三部分。這方面研究主要集中在視覺搜索(Conci et al., 2011)、注意瞬脫(van Zoest et al., 2012)以及空間注意分配(Deubel, 2008)等; 而人們對(duì)注意調(diào)節(jié)SFM知覺時(shí)間特性的了解還比較有限。根據(jù)上述“兩階段”觀點(diǎn)(Andersen & Bradley, 1998; Cavanagh, 1992; Nishida et al., 2018; Treue et al., 1991), 運(yùn)動(dòng)知覺中低水平加工先于高水平加工; 高水平加工機(jī)制直接調(diào)節(jié)低水平加工, 但它同時(shí)又依賴低水平加工的輸出結(jié)果; 兩者相互協(xié)作, 完成運(yùn)動(dòng)知覺。因此, 注意調(diào)節(jié)運(yùn)動(dòng)信息加工的時(shí)間特性是運(yùn)動(dòng)知覺不同階段資源利用特點(diǎn)及知覺組織形成機(jī)制的重要內(nèi)容。

1.2 注意調(diào)節(jié)作用的眼動(dòng)機(jī)制

眼睛運(yùn)動(dòng)是視覺運(yùn)動(dòng)知覺的重要線索, 早在1925年, Helmholtz就提出, 運(yùn)動(dòng)識(shí)別源于眼動(dòng)追蹤信號(hào)(Cavanagh, 1992); 眼動(dòng)決定了視覺系統(tǒng)對(duì)運(yùn)動(dòng)方向和距離的判斷(Rock et al., 1987)、產(chǎn)生似動(dòng)知覺(Pomerantz, 1970)以及在缺乏消除刺激歧義信息時(shí), 提供知覺判斷所依賴的信號(hào)(Laubrock et al., 2008)。神經(jīng)科學(xué)研究表明, 眼動(dòng)與注意轉(zhuǎn)移有共同神經(jīng)基礎(chǔ)(Grosbras et al., 2005)。眼跳峰速度越快、幅度越大, 注意系統(tǒng)激活程度越高(Di Stasi et al., 2013)。此外, 微眼跳是注視過程中的微小跳動(dòng), 與空間注意密切相關(guān)(Meyberg, Sinn et al., 2017; Meyberg, Sommer et al., 2017)。它的頻率變化反映了視覺注意的轉(zhuǎn)移(Engbert & Kliegl, 2003)與注意強(qiáng)度(Kaneko et al., 2011)變化, 隨注意需求增加而增加(Krueger et al., 2019); 微眼跳方向與注意方向也密切相關(guān)(Hafed & Clark, 2002; Rolfs et al., 2004)。因此, 微眼跳可以作為研究視覺空間注意時(shí)間分布的手段, 用來追蹤空間注意隨時(shí)間持續(xù)分配特點(diǎn)(Ryan et al., 2019)。在SFM知覺中, Stonkute等(2012)采用微眼跳為注意指標(biāo)進(jìn)一步發(fā)現(xiàn), 被試在判斷雙穩(wěn)態(tài)刺激(隨機(jī)點(diǎn)構(gòu)成的球體)旋轉(zhuǎn)方向發(fā)生反轉(zhuǎn)時(shí)(1秒左右), 微眼跳頻率明顯增加。結(jié)合其他指標(biāo), Stonkute等認(rèn)為, SFM知覺中的刺激反轉(zhuǎn)取決于對(duì)虛構(gòu)球體及其不規(guī)則表面的注意, 而不是對(duì)表面上單個(gè)點(diǎn)的注意跟蹤。由此可見, 微眼跳也可以作為SFM知覺中注意產(chǎn)生作用的有效手段。

1.3 研究假設(shè)

綜上所述, 雖然多數(shù)研究認(rèn)為, 注意能夠調(diào)節(jié)運(yùn)動(dòng)知覺, 但也有不同觀點(diǎn)。其原因可能在于SFM運(yùn)動(dòng)知覺在不同加工階段(水平)中受到注意的調(diào)節(jié)作用存在差異。要澄清這一問題, 還應(yīng)該進(jìn)一步明確注意在SFM知覺過程中產(chǎn)生作用的時(shí)間進(jìn)程。然而, 到目前為止, 人們對(duì)注意在SFM知覺不同階段發(fā)揮作用時(shí)間進(jìn)程的了解還比較有限。為了進(jìn)一步揭示注意對(duì)SFM知覺不同階段調(diào)節(jié)作用的時(shí)間特性, 本研究擬在Cavanagh (1992)、Nishida等(2018)、Andersen和Bradley (1998)以及Treue等(1991)的“兩階段”理論基礎(chǔ)上, 通過控制外源性深度視覺線索, 分析SFM知覺中的眼動(dòng)特征, 根據(jù)Egeth和Yantis (1997)提出的注意時(shí)間進(jìn)程三階段理論, 進(jìn)一步明確整體運(yùn)動(dòng)知覺中低水平加工與高水平加工之間的時(shí)間邏輯關(guān)系以及注意調(diào)節(jié)兩個(gè)階段的時(shí)間進(jìn)程。我們假設(shè), 注意能否參與SFM知覺的早期加工取決于知覺輸入的確定性, 當(dāng)存在外源性深度視覺線索時(shí), 注意資源被優(yōu)先獲得, 從而加快運(yùn)動(dòng)信息整合; 而在缺乏深度線索(雙穩(wěn)態(tài)模糊刺激)時(shí), 注意資源對(duì)整體運(yùn)動(dòng)知覺的調(diào)節(jié)作用主要發(fā)生在加工的后期階段。為了驗(yàn)證上述假設(shè), 我們?cè)O(shè)置了有、無深度線索的兩類SFM刺激, 并分析被試對(duì)這兩類刺激的知覺判斷及眼動(dòng)特點(diǎn)。我們預(yù)期, 有深度線索的判斷時(shí)成績(jī)好于無線索; 而兩種條件下的微眼跳頻次在不同時(shí)程上表現(xiàn)出明顯不同, 反映出注意的動(dòng)態(tài)變化過程。有線索時(shí), 由于SFM刺激中兩組運(yùn)動(dòng)方向相反的點(diǎn)之間差異明顯, 因此, 不同知覺判斷過程中微眼跳頻次之間的差異出現(xiàn)更早, 反映了注意更早的投入。相反, 在無線索時(shí), 由于SFM刺激中兩組運(yùn)動(dòng)方向相反的點(diǎn)之間存在競(jìng)爭(zhēng), 注意選擇較為困難, 不同知覺判斷時(shí)微眼跳頻率之間的差異要晚一些才會(huì)出現(xiàn)。

2 方法

2.1 被試

根據(jù)Cohen (1988, p26)對(duì)檢驗(yàn)中Cohen's= 0.80為高效應(yīng)量的定義, 采用G*Power 3.19軟件計(jì)算Cohen's= 0.80、α = 0.05、= 22時(shí), 1?β ≈ 0.95。因此, 共招募22名被試參加實(shí)驗(yàn), 其中男10人, 女12人。平均年齡23歲。被試的視力或校正視力在1.00以上, 色覺正常。實(shí)驗(yàn)后, 被試獲得一定報(bào)酬。被試在實(shí)驗(yàn)前需要簽署知情同意書。研究得到所在單位倫理委員會(huì)批準(zhǔn)。

2.2 實(shí)驗(yàn)材料與設(shè)備

實(shí)驗(yàn)刺激由30個(gè)直徑約0.2°視角的白色或灰色圓點(diǎn)構(gòu)成。這些圓點(diǎn)隨機(jī)分布在5°×5°范圍內(nèi)(見圖1a), 并按橢圓路徑以平均5°/s速度協(xié)同運(yùn)動(dòng), 從而形成轉(zhuǎn)動(dòng)的立體球體, 即運(yùn)動(dòng)形成的結(jié)構(gòu)(SFM)。轉(zhuǎn)動(dòng)球體中心位于屏幕中心; 屏幕背景為黑色。

從俯視視角看, 球體可以被看成順時(shí)針(clock- wise, CW)或逆時(shí)針(counterclock-wise, CCW)旋轉(zhuǎn)。順時(shí)針旋轉(zhuǎn)時(shí), 距離觀察者較近端圓點(diǎn)向左運(yùn)動(dòng), 遠(yuǎn)端圓點(diǎn)向右運(yùn)動(dòng); 而逆時(shí)針旋轉(zhuǎn)時(shí)則相反。在有些刺激中, 通過圓點(diǎn)的亮度變化, 提供深度線索。觀察者會(huì)將較亮的圓點(diǎn)知覺為距離自己更近, 而較暗圓點(diǎn)距離較遠(yuǎn)(Jiang et al., 1998); 此外, 盡管近端和遠(yuǎn)端兩個(gè)面運(yùn)動(dòng)時(shí)在視網(wǎng)膜上所形成的像具有相同速度, 但知覺到的近端面速度更快(Fernandez & Farell, 2006)。

本研究設(shè)置了3種刺激條件(見圖1a)。在第一種條件下, 當(dāng)圓點(diǎn)在橢圓軌跡上向左運(yùn)動(dòng)時(shí), 圓點(diǎn)為白色; 向右運(yùn)動(dòng)時(shí)則為灰色; 整個(gè)刺激的平均亮度約為14 cd/m。這種設(shè)置可以形成球體做CW旋轉(zhuǎn)運(yùn)動(dòng)。第二種條件則相反, 球體被看作CCW旋轉(zhuǎn)運(yùn)動(dòng)。第三種刺激中所有圓點(diǎn)的亮度相同, 整個(gè)刺激的平均亮度與前兩種刺激亮度相同; 刺激沒有任何深度線索; 被試對(duì)球體旋轉(zhuǎn)方向判斷完全依賴圓點(diǎn)運(yùn)動(dòng), 既可以看成CW旋轉(zhuǎn), 也可以看成CCW旋轉(zhuǎn)。因此, 它是一種“模棱兩可的” (ambiguous, AMB)刺激。

實(shí)驗(yàn)中采用德國(guó)SMI HiSpeed 眼動(dòng)儀記錄被試眼動(dòng)數(shù)據(jù), 眼動(dòng)儀采樣率為350 Hz。實(shí)驗(yàn)刺激呈現(xiàn)在19吋顯示器(分辨率為1024×768; 刷新頻率為120 Hz)上; 實(shí)驗(yàn)刺激和行為反應(yīng)由計(jì)算機(jī)通過e-Prime軟件控制和記錄。

圖1 實(shí)驗(yàn)刺激(a)和實(shí)驗(yàn)流程(b)

2.3 實(shí)驗(yàn)設(shè)計(jì)與過程

實(shí)驗(yàn)采用2(深度線索：有、無) × 2(知覺判斷：向左、向右)被試內(nèi)設(shè)計(jì), 其中一個(gè)因素為線索條件, 即有無深度線索; 有線索條件包括CW和CCW刺激, 而AMB刺激則屬于無線索條件。另一個(gè)因素是被試的知覺判斷, 包括做順時(shí)針和逆時(shí)針兩種判斷。

實(shí)驗(yàn)流程見圖1b。在實(shí)驗(yàn)中, 每個(gè)試次包含“+” 500 ms; 旋轉(zhuǎn)球體呈現(xiàn)950 ms; 1500 ms反應(yīng)窗口后, 呈現(xiàn)500 ms由灰色和白色點(diǎn)隨機(jī)分布構(gòu)成的掩蔽刺激, 以消除視覺短時(shí)記憶或后像的影響(Jiang et al., 1998)。被試雙手握住鼠標(biāo), 兩個(gè)拇指分別放在鼠標(biāo)的按鍵上; 任務(wù)是判斷球體的旋轉(zhuǎn)方向。當(dāng)將球體判斷成CW運(yùn)動(dòng)(近端圓點(diǎn)向左運(yùn)動(dòng))時(shí), 用左手拇指按鼠標(biāo)左鍵; CCW運(yùn)動(dòng)時(shí)則用右手拇指按右鍵。在整個(gè)實(shí)驗(yàn)中, CW和CCW兩種旋轉(zhuǎn)刺激各重復(fù)60次; AMB刺激則重復(fù)80次, 共200個(gè)試次。隨機(jī)排列后, 分成5個(gè)組塊, 每個(gè)組塊40個(gè)試次。在每個(gè)組塊的前后各有一個(gè)填充試次。在正式實(shí)驗(yàn)開始前, 被試完成一組20個(gè)試次的練習(xí)。正式實(shí)驗(yàn)中, 每個(gè)組塊前對(duì)眼動(dòng)儀進(jìn)行9點(diǎn)校準(zhǔn), 視距為60 cm。組塊之間休息3~5分鐘。眼動(dòng)儀和計(jì)算機(jī)分別記錄被試在實(shí)驗(yàn)過程中的眼動(dòng)數(shù)據(jù)和按鍵反應(yīng)。

2.4 數(shù)據(jù)分析方法

為了區(qū)分被試對(duì)不同刺激做出的不同反應(yīng), 我們分別用大寫CW、CCW和AMB表示3種不同刺激; 將被試做出的順時(shí)針(近端向左)和逆時(shí)針(近端向右)判斷分別用小寫字母cw和ccw表示。實(shí)驗(yàn)中, 被試對(duì)三種旋轉(zhuǎn)刺激的判斷都可能有cw和ccw兩種; 如用字母組合CW-cw和CW-ccw表示對(duì)CW旋轉(zhuǎn)刺激的刺激?反應(yīng)組合; 同樣, 用CCW-cw和CCW-ccw、AMB-cw和AMB-ccw分別表示對(duì)CCW和AMB的刺激?反應(yīng)組合。

微眼跳是眼睛在注視點(diǎn)內(nèi), 持續(xù)的微小運(yùn)動(dòng), 可以作為研究視覺空間注意時(shí)間分布的有效指標(biāo), 用來追蹤空間注意隨時(shí)間持續(xù)分配特點(diǎn)(Ryan et al., 2019)。本研究采用Otero-Millan等(2014)提出的微眼跳提取方法(參數(shù)設(shè)置：幅度上限 = 15°、相鄰微眼跳最小時(shí)間間隔 = 20 ms、最小眼跳時(shí)間 = 10 ms, 檢測(cè)閾限 = 1.60), 并將微眼跳定義為幅度在2°視角以內(nèi)(占99.10%)、峰速度小于150°/s (占97.30%) (Bonneh et al., 2015)。此外, 采用雙眼微眼跳作為微眼跳指標(biāo), 因?yàn)橹挥须p眼微眼動(dòng)能夠誘發(fā)空間注意(張陽(yáng)等, 2016)。

為了進(jìn)一步了解微眼跳頻次隨時(shí)間變化的過程, 我們對(duì)不同條件下微眼跳頻次按方向(向左為負(fù)值, 向右為正值)進(jìn)行分類, 參考Bonneh等(2015)以及Hermens和Walker (2010)的方法分析不同方向微眼跳頻次變化的時(shí)間進(jìn)程。具體步驟包括：(1)截取每個(gè)試次刺激呈現(xiàn)前500 ms和呈現(xiàn)后1000 ms為一段; (2)用1(向右)和?1(向左)分別將每段中出現(xiàn)微眼跳時(shí)刻標(biāo)記出來; (3)以100 ms時(shí)間窗寬度、1 ms為步長(zhǎng), 計(jì)算平均每秒次數(shù); (4)分別計(jì)算每個(gè)被試在不同條件下所有試次的平均值(類似腦電的疊加過程), 以備統(tǒng)計(jì)分析。

在實(shí)驗(yàn)中, 極個(gè)別遺漏反應(yīng)以及反應(yīng)時(shí)超出±3個(gè)標(biāo)準(zhǔn)差以外的試次(約占1.7%)被剔除。由于對(duì)CW做ccw判斷(8.40%)和對(duì)CCW做cw判斷(6.14%)的比例較低, 結(jié)果中不對(duì)CW-ccw和CCW-cw的反應(yīng)比例和反應(yīng)時(shí)進(jìn)行分析, 而是采用2(深度線索：有、無) × 2(反應(yīng)方向：向左、向右)對(duì)知覺判斷成績(jī)及相應(yīng)的微眼跳峰速度、幅度、時(shí)間進(jìn)行方差分析。此外, 由于微眼跳頻次按眼跳方向進(jìn)行了劃分, 因此, 僅對(duì)各種條件下不同方向微眼跳頻次之間差異進(jìn)行檢驗(yàn)。同時(shí), 還分析了不同條件下微眼跳頻次隨時(shí)間變化的過程。首先, 通過檢驗(yàn)按時(shí)間逐點(diǎn)(步長(zhǎng)為1 ms)比較不同條件下微眼跳頻次的差異。然后, 當(dāng)連續(xù)50 ms時(shí)間窗的統(tǒng)計(jì)檢驗(yàn)顯著時(shí), 則確定為顯著時(shí)間窗, 并采用該時(shí)間窗內(nèi)的平均值進(jìn)行差異檢驗(yàn)。

3 結(jié)果

3.1 知覺判斷

被試對(duì)3種旋轉(zhuǎn)刺激的判斷比例和反應(yīng)時(shí)見圖2。方差分析表明, 對(duì)判斷百分比而言, 深度線索主效應(yīng)顯著,(1, 21) = 310.39,< 0.001, η= 0.94, 有線索顯著大于無線索; 并且對(duì)有深度線索的旋轉(zhuǎn)刺激(CW和CCW)做出相應(yīng)判斷的比例都分別高于對(duì)無線索刺激(AMB)的判斷比例, 即%> %,(21) = 4.989,< 0.001, Cohen's= 2.18; %> %,(21) = 8.66,< 0.001, Cohen's= 3.78。而對(duì)AMB刺激的cw和ccw判斷比例之間差異不顯著; 且它們分別與機(jī)遇水平(50%)之間的差異也不顯著。反應(yīng)方向主效應(yīng)以及兩個(gè)因素的交互作用均不顯著。

圖2 不同刺激的判斷百分比(a)和反應(yīng)時(shí)(b)。(注：①*表示p < 0.05; **表示p < 0.01; ②誤差線為標(biāo)準(zhǔn)誤)

在判斷反應(yīng)時(shí)上, 深度線索主效應(yīng)顯著,(1, 21) = 32.41,< 0.001, η= 0.61, 無線索顯著大于有線索。反應(yīng)方向主效應(yīng)顯著,(1, 21) = 5.24,= 0.032, η= 0.20, 判斷向右旋轉(zhuǎn)的時(shí)間顯著大于向左。兩者交互作用顯著,(1, 21) = 5.91,= 0.024, η= 0.22。簡(jiǎn)單效應(yīng)分析表明, 有線索(CW、CCW)條件下, 不同方向判斷反應(yīng)時(shí)之間差異不顯著; 而在無線索(AMB)條件下, 判斷向右旋轉(zhuǎn)的反應(yīng)時(shí)顯著大于向左旋轉(zhuǎn)判斷, RT< RT,(21) = –2.76,= 0.012, Cohen's= –1.21。

3.2 眼睛位置變化

在實(shí)驗(yàn)過程中, 要求被試眼睛注視刺激的中心位置。然而, 被試的眼睛并不是完全靜止, 而是追隨圓點(diǎn)小幅移動(dòng), 見圖3。圖3a是眼睛位置的空間分布; 從圖中可以看出, 不論是有線索的刺激(CW), 還是模糊刺激(AMB), 當(dāng)被試做順時(shí)針運(yùn)動(dòng)(cw)判斷時(shí), 眼睛都向左移動(dòng); 相反, 被試對(duì)CCW和AMB刺激做ccw判斷時(shí), 眼睛則向右移動(dòng)。因此, 被試在判斷過程中眼睛移動(dòng)與判斷運(yùn)動(dòng)的方向一致。此外, 圖3b顯示, 眼睛移動(dòng)滯后刺激出現(xiàn)200 ms左右; 此后眼睛位置隨時(shí)間緩慢向所判斷的方向移動(dòng)。

3.3 微眼跳

微眼跳的峰速度、幅度、時(shí)間和頻次統(tǒng)計(jì)結(jié)果見圖4。方差分析顯示, 有深度線索條件下的微眼跳峰速度都顯著大于無線索條件的眼跳峰速度,(1, 21) = 19.41,0.001, η= 0.48; 不同反應(yīng)及其與深度線索之間的交互作用均不顯著。微眼跳幅度也表現(xiàn)出類似趨勢(shì), 有深度線索條件下的微眼跳幅度更大,(1, 21) = 31.32,0.001, η= 0.60; 不同反應(yīng)及其與深度線索之間的交互作用均不顯著。眼跳時(shí)間沒有表現(xiàn)出任何顯著差異。

此外, 各種條件下, 不同方向的(向左和向右)微眼跳頻次也存在差異。當(dāng)被試判斷刺激做cw (近端向左)運(yùn)動(dòng)時(shí), 向左的微眼跳頻次顯著大于向右, 即CW-cw：(21) = 3.81,= 0.001, Cohen's= 1.66; AMB-cw：(21) = –2.49,= 0.021, Cohen's= –1.08。相反, 當(dāng)被試判斷刺激ccw (近端向右)運(yùn)動(dòng)時(shí), 則向右的微眼跳頻次顯著大于向左, CCW- ccw：(21) = 2.15,= 0.043, Cohen's= 0.94; AMB- ccw：(21) = –2.29,= 0.033, Cohen's= –1.00。

不同方向微眼跳頻次變化的時(shí)間進(jìn)程見圖5。統(tǒng)計(jì)分析顯示, 不論是否有深度線索, 被試在判斷刺激近端向左(cw)或向右(ccw)旋轉(zhuǎn)時(shí)的微眼跳具有明顯的偏向性, 即微眼跳更多朝向知覺判斷方向。在判斷方向內(nèi)部差異不顯著(見圖5a和5b); 而不同判斷方向之間存在顯著差異, 但在時(shí)間進(jìn)程上有所不同(見圖5c和5d)。當(dāng)有深度線索(CW-cw和CCW-ccw)時(shí), 顯著差異時(shí)間窗分別在150~400 ms ((21) = –2.49,= 0.021, Cohen's= –1.09)和500~975 ms ((21) = –3.17,= 0.005, Cohen's= –1.38)。而在無深度線索條件下(AMB-cw和AMB-ccw), 顯著差異時(shí)段分別為340~510 ms ((21) = –2.45,= 0.024, Cohen's= –1.07)和700~950 ms ((21) = –2.13,= 0.045, Cohen's= –0.93)。即有深度線索時(shí), 在約150 ms左右眼睛就開始對(duì)CW和CCW旋轉(zhuǎn)進(jìn)行區(qū)分; 而無線索條件下, 則要到340 ms才能對(duì)球體旋轉(zhuǎn)方向做出判斷。

圖3 觀看不同刺激時(shí)眼睛位置及其隨刺激呈現(xiàn)時(shí)間變化。(a) 眼睛位置的空間分布; (b) 眼睛位置隨刺激呈現(xiàn)變化的時(shí)間進(jìn)程。(注：圖中0點(diǎn)為旋轉(zhuǎn)刺激的中心位置, 即屏幕中心位置。“水平位置”和“垂直位置”的值大于0位于中心位置右側(cè)和下方; 小于0則位于左側(cè)和上方。)

圖4 不同條件的微眼跳參數(shù)比較。(a) 微眼跳峰速度; (b) 微眼跳幅度; (c) 微眼跳時(shí)間; (d)微眼跳頻次。(注：①*表示p < 0.05; **表示p < 0.01; ②誤差線為標(biāo)準(zhǔn)誤)

圖5 不同方向微眼跳頻次隨時(shí)間變化進(jìn)程比較。(a) 有線索(CW)與無線索(AMB)的相同判斷(cw)時(shí)微眼跳頻次; (b) CCW-ccw和AMB-ccw的微眼跳頻次; (c) 有線索條件下(CW和CCW)相應(yīng)判斷時(shí)微眼跳頻次; (d) 無線索條件下(AMB)不同判斷時(shí)微眼跳頻次。(注：①陰影部分為差異顯著時(shí)間窗; ② *表示p < 0.05; **表示p < 0.01。)

4 討論

通過將亮度對(duì)比設(shè)置成深度線索, 結(jié)果顯示, 深度線索有助于SFM知覺判斷, 與模糊刺激條件相比, 在有線索條件下, 判斷更加快、更加肯定(百分比更高); 眼睛位置移動(dòng)方向和微眼跳方向都分別與知覺判斷的運(yùn)動(dòng)方向具有一致性; 微眼跳次數(shù)、峰速度和幅度也都分別表現(xiàn)出深度線索的促進(jìn)效應(yīng)。在有深度線索條件下, 較亮圓點(diǎn)和較暗圓點(diǎn)的運(yùn)動(dòng)速度相同而方向相反。由于相同速度的低亮度刺激被知覺的速度小于高亮度刺激(Stone & Thompson, 1992; Thompson, 1982), 兩組點(diǎn)形成了運(yùn)動(dòng)視差。雙眼運(yùn)動(dòng)視差隨時(shí)間變化為立體運(yùn)動(dòng)知覺提供依據(jù)(Gumming & Parker, 1994)。于是, 低亮度圓點(diǎn)被知覺成距離觀察者更遠(yuǎn); 而高亮度圓點(diǎn)則被知覺為距離更近。因此, 亮度對(duì)比幫助視覺系統(tǒng)很快形成整體運(yùn)動(dòng)知覺, 并迅速做出判斷。相反, 在無線索條件下, 兩個(gè)方向的運(yùn)動(dòng)之間存在競(jìng)爭(zhēng), 需要更多加工過程才能完成判斷, 判斷時(shí)間也延長(zhǎng)。因?yàn)樵趯?duì)模棱兩可的SFM刺激知覺判斷中, 視覺系統(tǒng)需要在兩個(gè)對(duì)立的知覺解釋中進(jìn)行選擇, 從而判斷出三維結(jié)構(gòu)旋轉(zhuǎn)方向(Park & Tadin, 2018)。不過, 無線索條件下不同判斷方向反應(yīng)時(shí)之間的差異還有待進(jìn)一步研究。

不論是Cavanagh (1992)和Nishida等(2018)將運(yùn)動(dòng)知覺區(qū)分為“低水平”和“高水平”兩個(gè)加工階段, 還是Andersen和Bradley (1998)和Treue等(1991)將SFM知覺劃分為速度測(cè)量和三維物體表面構(gòu)建兩個(gè)加工過程; “兩階段”加工理論為人們進(jìn)一步認(rèn)識(shí)了SFM運(yùn)動(dòng)知覺的內(nèi)在機(jī)制提供了重要思路。在本研究中, 從知覺判斷結(jié)果無法明確區(qū)分SFM知覺的不同階段。但從微眼跳隨時(shí)間變化過程來看, 在有深度線索條件下, 不同知覺判斷時(shí)的微眼跳頻率在150 ms時(shí)便出現(xiàn)顯著差異(見圖5c); 眼睛位置隨時(shí)間變化過程(見圖3)顯示, 所有條件下, 在運(yùn)動(dòng)刺激出現(xiàn)(圓點(diǎn)開始移動(dòng))約200 ms內(nèi), 眼睛基本上是靜止在中心位置。這一段時(shí)間內(nèi)(0~200 ms)注意系統(tǒng)似乎還沒有參與知覺加工, 可以看成是第一階段。200 ms開始, 眼睛通過小幅度的微眼跳緩慢移向所判斷的方向; 這種短距離眼動(dòng)追蹤能夠?yàn)檫\(yùn)動(dòng)知覺提供有用信息(Schütz et al., 2011), 也符合微眼跳的反應(yīng)特點(diǎn), 即刺激呈現(xiàn)200 ms后, 朝向預(yù)期位置的微眼跳才會(huì)明顯增加(Rolfs et al., 2004)。因此, 200 ms以后是加工的第二階段。

如果以150~200 ms作為SFM知覺加工兩個(gè)階段的分界線; 那么, 這兩個(gè)階段內(nèi)又會(huì)經(jīng)歷哪些加工？注意時(shí)間進(jìn)程(指向、駐留和移動(dòng))的三個(gè)部分(Egeth & Yantis, 1997)又如何在這兩個(gè)階段發(fā)揮作用呢？

4.1 速度測(cè)量(低水平加工)階段

顏色和亮度是運(yùn)動(dòng)知覺的兩種載體(Papathomas et al., 1991)。與形狀相比, 亮度對(duì)SFM知覺能力的影響更大(Sara et al., 2017)。在有深度線索條件下CW-cw與CCW-ccw的微眼跳差異則出現(xiàn)在150 ms左右(圖5c)。在0~150 ms內(nèi), 視覺系統(tǒng)需要完成對(duì)運(yùn)動(dòng)亮點(diǎn)的感覺登記、速度判斷與整合(分組)等(Dombrowe et al., 2010); 它可能包括了用于從SFM運(yùn)動(dòng)中感知結(jié)構(gòu)點(diǎn)運(yùn)動(dòng)所需的50~85 ms (Treue et al., 1991; Alais et al., 2011)和誘發(fā)微眼跳所需的70 ms左右(潛伏期) (Horwitz & Albright, 2003)。

因此, 低水平加工階段主要發(fā)生在0~150 ms內(nèi), 此階段不需要注意參與, 時(shí)?空頻率覺察器探測(cè)局部運(yùn)動(dòng)信號(hào), 視覺系統(tǒng)主要完成對(duì)刺激基本特征(顏色、亮度、運(yùn)動(dòng))登記, 屬于Cavanagh (1992)、Nishida等(2018)和Schmitt等(2018)等所提出的沒有注意參與的“低水平”自動(dòng)加工階段。不過, 也有研究認(rèn)為, 相對(duì)于其他刺激, 運(yùn)動(dòng)刺激在開始時(shí)就能捕獲注意(Smith & Abrams, 2018), 但這種優(yōu)勢(shì)僅能維持約100 ms (Ramirez-Moreno et al., 2013)。SFM知覺的早期階段是否有注意參與還有待進(jìn)一步研究。

4.2 三維物體表面構(gòu)建(高水平加工)階段

視覺系統(tǒng)通過對(duì)已登記的運(yùn)動(dòng)信息進(jìn)行選擇和抑制、形成知覺分組, 才能構(gòu)建三維結(jié)構(gòu)(Andersen & Bradley, 1998; Treue et al., 1991)。這些加工都需要注意高度參與(Stelmach et al., 1994)。我們將結(jié)合注意時(shí)間進(jìn)程(指向、駐留和移動(dòng)) (Egeth & Yantis, 1997), 對(duì)注意在此階段的調(diào)節(jié)作用進(jìn)行深入分析。

注意指向 150 ms之后, 在有深度線索條件下, 不同知覺判斷時(shí)的微眼跳頻率開始出現(xiàn)顯著差異(見圖5c)。這意味著注意系統(tǒng)開始集中到相應(yīng)的知覺組塊(具有相同運(yùn)動(dòng)方向的較亮圓點(diǎn))上, 即注意通過調(diào)節(jié)知覺組織(Kasai & Takeya, 2012), 將這些信號(hào)整合成運(yùn)動(dòng)矢量流, 并把它選擇成為目標(biāo)(Conci et al., 2011)。ERP研究表明, 注意對(duì)知覺組織的快速調(diào)節(jié)作用發(fā)生在180~200 ms內(nèi)(Kasai & Takeya, 2012), 并在240~300 ms之內(nèi)選擇相應(yīng)目標(biāo)(Andersen & Muller, 2010); 而在眼動(dòng)研究中, 需要約250 ms (Peterson & Kramer, 2001)。根據(jù)注意的特征整合理論(Treisman & Gelade, 1980; Treisman & Gormican, 1988), 在完成基本特征登記后, 注意就會(huì)像“膠水”一樣將它們粘在一起, 形成知覺整體。此階段應(yīng)該是Egeth和Yantis (1997)所說的注意指向。對(duì)于有深度線索的刺激而言, 運(yùn)動(dòng)方向相反的兩組點(diǎn)的亮度差異很明顯, 較亮的點(diǎn)更容易被注意選擇, 較暗的點(diǎn)則更容易被抑制。而當(dāng)運(yùn)動(dòng)方向相反的兩組點(diǎn)亮度相同時(shí)(無深度線索), 注意選擇和抑制都會(huì)比較困難, 大約需要340 ms才能完成(見圖5d)。這是因?yàn)閷?duì)非注意刺激的抑制需要約360 ms (Andersen & Muller, 2010)。因此, 注意系統(tǒng)在150 ms至340 ms這段時(shí)間完成對(duì)一組運(yùn)動(dòng)點(diǎn)的選擇和對(duì)另一組點(diǎn)的抑制, 通過眼睛定向注意將視覺特征整合成SFM知覺(Jiang et al., 2008), 并且需要額外時(shí)間, 在更高層次上完成運(yùn)動(dòng)方向判斷。

注意駐留 視覺注意不是一種高速轉(zhuǎn)換機(jī)制, 而是一種持續(xù)的狀態(tài), 在這種狀態(tài)下, 促進(jìn)對(duì)相關(guān)目標(biāo)的表征(Ward et al., 1996)。因此, 當(dāng)注意定向到相應(yīng)刺激上以后, 會(huì)在那里停留一段時(shí)間(Egeth & Yantis, 1997)。本研究中, 無論有無深度線索, 注意都會(huì)在目標(biāo)上停留一段時(shí)間, 表現(xiàn)為在一定時(shí)間窗(有線索：150~400 ms; 無線索：340~510 ms)內(nèi)不同知覺判斷時(shí)的微眼跳頻率差異顯著。在這段時(shí)間里, 視覺系統(tǒng)繼續(xù)抑制分心刺激(Forschack et al., 2017; van Zoest et al., 2016)、整合被選擇和被抑制的兩組點(diǎn)(Festman & Braun, 2012)等。只有在完成這些加工之后, 注意才會(huì)轉(zhuǎn)移, 傳播到整體; 這至少需要200~300 ms (Stoppel et al., 2012)。因此, 在SFM知覺中, 注意的駐留時(shí)間應(yīng)該持續(xù)約200 ms左右。不過, 為什么有深度線索刺激的注意駐留時(shí)間(250 ms)比無線索條件下(170 ms)更長(zhǎng)還有待進(jìn)一步研究。

注意轉(zhuǎn)移 完成知覺分組后, 由知覺分組構(gòu)成的虛擬輪廓成為產(chǎn)生整體運(yùn)動(dòng)知覺的基礎(chǔ)(Caplovitz & Tse, 2007)。局部運(yùn)動(dòng)知覺和整體運(yùn)動(dòng)知覺具有不同的神經(jīng)機(jī)制(Hedges et al., 2011); 在加工無線索(兩可)運(yùn)動(dòng)結(jié)構(gòu)體時(shí), 神經(jīng)元間的相關(guān)性顯著高于加工有線索(非兩可)結(jié)構(gòu)體或隨機(jī)二維運(yùn)動(dòng)(Wasmuht et al., 2019)。因此, 識(shí)別整體運(yùn)動(dòng)(Group Motion)比局部運(yùn)動(dòng)(Element Motion)需要更多注意資源(Ayd?n et al., 2011)。本研究中, 在完成局部特征分析并選擇相應(yīng)組塊后, 注意系統(tǒng)需要從單一組塊轉(zhuǎn)移到兩個(gè)運(yùn)動(dòng)方向相反的組塊上才能構(gòu)建三維結(jié)構(gòu)(整體)。圖5c和圖5d表明, 有無深度線索條件下分別500~970 ms和700~950 ms出現(xiàn)了兩個(gè)存在顯著差異的時(shí)間窗, 它們很可能標(biāo)志著注意從局部向整體的轉(zhuǎn)移。因?yàn)橹鲃?dòng)轉(zhuǎn)移注意可以改善整體運(yùn)動(dòng)的檢測(cè), 促進(jìn)整體運(yùn)動(dòng)方向知覺的判斷(Ishii et al., 2013)。

在對(duì)整體運(yùn)動(dòng)信息進(jìn)行加工時(shí), 視覺系統(tǒng)通過提取整體運(yùn)動(dòng)特征, 并使用整體運(yùn)動(dòng)信息估計(jì)局部運(yùn)動(dòng)特征(Rider et al., 2016), 實(shí)現(xiàn)局部運(yùn)動(dòng)的雙眼信息融合(Cai et al., 2019)。因此, 在兩種條件下的第二個(gè)時(shí)間窗內(nèi)很可能是對(duì)整體結(jié)構(gòu)中的局部元素進(jìn)行集中注意, 以進(jìn)一步確認(rèn)整體結(jié)構(gòu)旋轉(zhuǎn)方向的判斷, 即通過自上而下信號(hào)(如對(duì)真實(shí)目標(biāo)方向的先驗(yàn)知識(shí))檢驗(yàn)局部運(yùn)動(dòng)(Born & Pack, 2002); 其內(nèi)在機(jī)制還有待深入探討。

5 結(jié)論

研究結(jié)果表明, 注意加快有深度線索的知覺判斷。SFM知覺過程可以以150~200 ms為界限分成速度計(jì)算和構(gòu)建三維結(jié)構(gòu)兩個(gè)階段; 注意對(duì)SFM知覺的調(diào)節(jié)作用主要發(fā)生在高水平加工階段(構(gòu)建三維結(jié)構(gòu)), 特別是無深度線索的知覺判斷。注意從150 ms開始指向選擇對(duì)象; 駐留持續(xù)約200 ms (150~340 ms)后, 有無深度線索條件下分別在500~ 970 ms和700~950 ms出現(xiàn)了兩個(gè)存在顯著差異的時(shí)間窗, 完成從局部運(yùn)動(dòng)矢量流轉(zhuǎn)移到整體運(yùn)動(dòng)方向的知覺判斷。

Alais, D., Apthorp, D., Karmann, A., & Cass, J. (2011). Temporal integration of movement: The time-course of motion streaks revealed by masking.(12), e28675. https://doi.org/10.1371/journal.pone.0028675

Andersen, R. A. & Bradley, D. C. (1998). Perception of three- dimensional structure from motion.,(6), 222–228.

Andersen, S. K., & Muller, M. M. (2010). Behavioral performance follows the time course of neural facilitation and suppression during cued shifts of feature-selective attention.(31), 13878–13882.

Ayd?n, M., Herzog, M. H., & ??men, H. (2011). Attention modulates spatio-temporal grouping.(4), 435–446.

Bartlett, L. K., Graf, E. W., Hedger, N., & Adams, W. J. (2019). Motion adaptation and attention: A critical review and meta-analysis.,, 290–301.

Bonneh, Y. S., Adini, Y., & Polat, U. (2015). Contrast sensitivity revealed by microsaccades.(9), 1–12.

Born, R. T., & Pack, C. C. (2002). Integration of motion signals for smooth pursuit eye movements.,(1), 453–455.

Burr, D., & Thompson, P. (2011). Motion psychophysics: 1985-2010.,(13), 1431–1456.

Cai, L. T., Yuan, A. E., & Backus, B. T. (2019). Binocular global motion perception is improved by dichoptic segregation when stimuli have high contrast and high speed.,(13), 1–17.

Caplovitz, G. P., & Tse, P. U. (2007). Rotating dotted ellipses: Motion perception driven by grouped figural rather than local dot motion signals.,(15), 1979– 1991.

Cavanagh, P. (1992). Attention-based motion perception.,(5076), 1563–1565.

Cavanagh, P., Hunt, A. R., Afraz, A., & Rolfs, M. (2010). Visual stability based on remapping of attention pointers.,(4), 147–153.

Chung, C. Y. L., & Khuu, S. K. (2014). The processing of coherent global form and motion patterns without visual awareness.,, 195. https://doi.org/ 10.3389/fpsyg.2014.00195

Cohen, J. (1988).. Hillsdale, New Jersey: Lawrence Erlbaum Associates.

Conci, M., T?llner, T., Leszczynski, M., & Müller, H. J. (2011). The time-course of global and local attentional guidance in Kanizsa-figure detection.,(9), 2456– 2464.

Deubel, H. (2008). The time course of presaccadic attention shifts.,(6), 630–640.

Di Stasi, L. L., Catenad, A., Ca?asc, J. J., Macknike, S. L., & Martinez-Conde, S. (2013). Saccadic velocity as an arousal index in naturalistic tasks.,(5), 968–975.

Dombrowe, I. C., Olivers, C. N. L., & Donk, M. (2010). The time course of color- and luminance-based salience effects.,, 189. https://doi.org/10.3389/ fpsyg.2010.00189

Egeth, H. E., & Yantis, S. (1997). Visual attention: Control, representation, and time course.,, 269–297.

Engbert, R., & Kliegl, R. (2003). Microsaccades uncover the orientation of covert attention.,(9), 1035–1045.

Fernandez, J. M., & Farell, B. (2006). A reversed structure- from-motion effect for simultaneously viewed stereo- surfaces.,(8-9), 1230–1241.

Festman, Y., & Braun, J. (2012). Feature-based attention spreads preferentially in an object-specific manner.,(1), 31–38.

Forschack, N., Andersen, S. K., & Müller, M. M. (2017). Global enhancement but local suppression in feature-based attention.,(4), 619– 627.

Franconeri, S., & Handy, T. (2007). Rapid shifts of attention between two objects during spatial relationship judgments.,(9), 582. https://doi.org/10.1167/7.9. 582

Grosbras, M. H., Laird, A. R., & Paus, T. (2005). Cortical regions involved in eye movements, shifts of attention, and gaze perception.,(1), 140–154.

Gumming, B. G., & Parker, A. J. (1994). Binocular mechanisms for detecting motion-in-depth.,(4), 483–495.

Hafed, Z. M., & Clark, J. J. (2002). Microsaccades as an overt measure of covert attention shifts.,(22), 2533–2545.

Haith, M. M. (1966). The response of the human newborn to visual movement.,(3), 235–243.

Hedges, J. H., Gartshteyn, Y., Kohn, A., Rust, N. C., Shadlen, M. N., Newsome, W. T., & Movshon, J. A. (2011). Dissociation of neuronal and psychophysical responses to local and global motion.,(23), 2023– 2028.

Hermens, F., & Walker, R. (2010). What determines the direction of microsaccades?,(4), 1–20.

Hirshkowitz, A., Biondi, M., & Wilcox, T. (2017). Cortical responses to shape-from-motion stimuli in the infant.,(1), 011014. https://doi.org/10.1117/1.nph. 5.1.011014

Horwitz, G. D., & Albright, T. D. (2003). Short-latency fixational saccades induced by luminance increments.,(2), 1333–1339.

Hubel, D. H., & Wiesel, T. N. (1962). Receptive fields, binocular interaction and functional architecture in the cat's visual cortex.,(1), 106–154.

Ishii, T., Motoyoshi, I., & Kamachi, M. G. (2013). Removal of attention facilitates global motion detection.,(1), 135–136.

Jiang, Y., Boehler, C. N., N?nnig, N., Düzel, E., Hopf, J. M., Heinze, H. J., & Schoenfeld M. A. (2008). Binding 3-D object perception in the human visual cortex.,(4), 553–562.

Jiang, Y., Pantle, A. J., & Mark, L. S. (1998). Visual inertia of rotating 3-D objects.,(2), 275–286.

Johnson, S. P., Davidow, J., Hall-Haro, C., & Frank, M. C. (2008). Development of perceptual completion originates in information acquisition.,(5), 1214–1224.

Kaneko, H., Itakura, S., & Inagami, M. (2011). Relationship between the frequency of microsaccade and attentional state.,(4), 332–332.

Kasai, T., & Takeya, R. (2012). Time course of spatial and feature selective attention for partly-occluded objects.(9), 2281–2289.

Krueger, E., Schneider, A., Sawyer, B., Chavaillaz, A., Sonderegger, A., Groner, R., & Hancock P. (2019). Microsaccades distinguish looking from seeing.,(6). https://doi.org/10.16910/ jemr.12.6.2

Kuldkepp, N., Kreegipuu, K., Raidvee, A., N??t?nen, R., & Allik, J. (2013). Unattended and attended visual change detection of motion as indexed by event-related potentials and its behavioral correlates.,, 476. https://doi.org/10.3389/fnhum.2013. 00476

Lamberty, K., Gobbelé, R., Schoth, F., Buchner, H., & Waberski, T. D. (2008). The temporal pattern of motion in depth perception derived from ERPs in humans.(2), 198–202.

Laubrock, J., Engbert, R., & Kliegl, R. (2008). Fixational eye movements predict the perceived direction of ambiguous apparent motion.,(14), 1–17.

Lin, Y., & Tadin, D. (2019). Motion perception: Slow development of center-surround suppression.,(18), R878–R880.

Martínez, G. A. R., & Parra, H. C. (2018). Bistable perception: Neural bases and usefulness in psychological research.,(2), 63–76.

Meyberg, S., Sinn, P., Engbert, R., & Sommer, W. (2017). Revising the link between microsaccades and the spatial cueing of voluntary attention.,, 47–60

Meyberg, S., Sommer, W., & Dimigen, O. (2017). How microsaccades relate to lateralized ERP components of spatial attention: A co-registration study.,, 64–80.

Motoyoshi, I., Ishii, T., & Kamachi, M. G. (2015). Limited attention facilitates coherent motion processing.,(13), 1. https://doi.org/10.1167/15.13.1

Nishida, S., Kawabe, T., Sawayama, M., & Fukiage, T. (2018). Motion perception: From detection to interpretation.,(20), 501–523.

Otero-Millan, J., Castro, J. L. A., Macknik, S. L., & Martinez- Conde, S. (2014). Unsupervised clustering method to detect microsaccades.,(2), 1–17.

Papathomas, T. V., Gorea, A., & Julesz, B. (1991). Two carriers for motion perception: Color and luminance.,(11), 1883–1891.

Park, W. J., & Tadin, D. (2018). Motion perception. In J. Serences (Ed.).(4th ed.) (pp. 415–488). Wiley.

Peterson, M. S., & Kramer, A. F. (2001). Attentional guidance of the eyes by contextual information and abrupt onsets.,, 1239–1249.

Pomerantz, J. R. (1970). Eye movements affect the perception of apparent (beta) movement.,(4), 193–194.

Ramachandran, V. S., & Anstis, S. M. (1983). Perceptual organization in moving patterns., 529–531.

Ramirez-Moreno, D. F., Schwartz, O., & Ramirez-Villegas, J. F. (2013). A saliency-based bottom-up visual attention model for dynamic scenes analysis.(2), 141–160.

Rider, A. T., Nishida, S., & Johnston, A. (2016). Multiple- stage ambiguity in motion perception reveals global computation of local motion directions.,(15), 7, 1–11.

Rock, I., Halper, F., DiVita, J., & Wheeler, D. (1987). Eye movement as a cue to figure motion in anorthoscopic perception.,(3), 344–352.

Rolfs, M., Engbert, R., & Kliegl, R. (2004). Microsaccade orientation supports attentional enhancement opposite a peripheral cue: Commentary on Tse, Sheinberg, and Logothetis (2003).,(10), 705–707.

Ryan, A. E., Keane, B., & Wallis, G. (2019). Microsaccades and covert attention: Evidence from a continuous, divided attention task.,(6). https://doi.org/10.16910/jemr.12.6.6

Sara, G., Tony, P., Roberto, B., Kerstin, H., & Mariagrazia, B. (2017). The effect of luminance condition on form, form-from-motion and motion perception.,(2), 65–72.

Schmitt, C., Klingenhoefer, S., & Bremmer, F. (2018). Preattentive and Predictive Processing of Visual Motion.,, 12399. https://doi.org/10.1038/ s41598-018-30832-9

Schütz, A. C., Braun, D. I., & Gegenfurtner, K. R. (2011). Eye movements and perception: A selective review.,(5), 9, 1–30.

Scocchia, L., Valsecchi, M., & Triesch, J. (2014). Top-down influences on ambiguous perception: The role of stable and transient states of the observer.,. https://doi.org/10.3389/fnhum.2014. 00979

Simion, F., Regolin, L., & Bulf, H. (2008). A predisposition for biological motion in the newborn baby.,(2), 809–813.

Smith, K. C., & Abrams, R. A. (2018). Motion onset really does capture attention.,(7), 1775–1784.

Stelmach, L. B., Herdman, C. M., & McNeil, K. R. (1994). Attentional modulation of visual processes in motion perception.,(1), 108–121.

Stone, L. S., & Thompson, P. (1992). Human speed perception is contrast dependent.,(8), 1535–1549.

Stonkute, S., Braun, J., & Pastukhov, A. (2012). The role of attention in ambiguous reversals of structure-from-motion., 7(5), e37734. https://doi.org/10.1371/journal. pone.0037734

Stoppel, C. M., Boehler, C. N., Strumpf, H., Krebs, R. M., Heinze, H. J., Hopf, J. M., & Schoenfeld, M. A. (2012). Spatiotemporal dynamics of feature-based attention spread: Evidence from combined electroencephalographic and magnetoencephalographic recordings.(28), 9671–9676.

Thompson, P. (1982). Perceived rate of movement depends on contrast.,(3), 377–380.

Treisman, A., & Gelade, G. (1980). A feature-integration theory of attention.(1), 97–136.

Treisman, A., & Gormican, S. (1988). Feature analysis in early vision: Evidence from search asymmetries.,(1), 15–48.

Treue, S., Husain, M., & Andersen, R. A. (1991). Human perception of structure from motion.,(1), 59–75.

Tsal, Y., & Kolbet, L. (1985). Disambiguating ambiguous figures by selective attention.,(1), 25–37.

van Rullen, R., Reddy, L., & Koch, C. (2005). Attention- driven discrete sampling of motion perception.,(14), 5291–5296.

van Zoest, W., Donk, M., & van der Stigchel, S. (2012). Stimulus-salience and the time-course of saccade trajectory deviations.,(8), 16–16.

van Zoest, W., Heimler, B., & Pavani, F. (2016). The oculomotor salience of flicker, apparent motion and continuous motion in saccade trajectories.,(1), 181–191.

Wallach, H., & O'Connell, D. N. (1953). The kinetic depth effect.,(4), 205–217.

Wang, L., Yang, X., Shi, J., & Jiang, Y. (2014). The feet have it: Local biological motion cues trigger reflexive attentional orienting in the brain., 217–224.

Ward, R., Duncan, J., & Shapiro, K. (1996). The slow time- course of visual attention.,(1), 79–109.

Wasmuht, D. F., Parker, A. J., & Krug, K. (2019). Interneuronal correlations at longer time scales predict decision signals for bistable structure-from-motion perception.,, 11449. https://doi.org/10.1038/ s41598-019-47786-1

Zhang, Y., Li, A., Han, Y., Zhang, S., & Zhang, M. (2016). The effect of microsaccade types on attention.(6), 29–37.

[張陽(yáng), 李艾蘇, 韓玉, 張少杰, 張明. (2016). 微眼動(dòng)類型對(duì)注意的影響.,(6), 29–37.]

Temporal dynamics of eye movements and attentional modulation in perceptual judgments of structure-from-motion (SFM)

DING Jinhong, WANG Yamin, JIANG Yang

(Beijing Key Lab of Learning and Cognition, Collage of Psychology, Capital Normal University, Beijing, 100048, China) (Department of Behavioral Science, College of Medicine, University of Kentucky, Lexington, KY 40536-0086, USA)

How attention plays a role in resolving ambiguous perceptual judgments is one of the age-old scientific questions. Understanding the processes of perceptual grouping, switching, processing speed, and awareness is a key step towards solving significant problems in applications such as computer vision and automatic driving involving three-dimensional space. The rotating three-dimensional (3D) structure from motion (SFM) is a well-known bistable ambiguous stimulus. Thus far, it is still an open question how attention, eye movements, and depth cues modulate perceptual judgments of rotating directions of a 3D SFM. As early as 1925, motion perception resulted from eye tracking signals was proposed by Helmholtz (Cavanagh, 1992). Pomerantz (1970) claimed that eye movement plays an important role in the occurrence of kinesthetic perception. Furthermore, neuroscience studies has supported a common neural basis for eye movement and attention transfer (Grosbras, Laird & Paus, 2005). The current study aimed to investigate the characteristics and the time course of eye movements during SFM perception by controlling exogenous visual cues and ascertain the effect of attention on SFM perception. Using advanced eyemovements analysis, we investigated how attention under both unambiguous and ambiguous depth cues modulate perceptual judgments of rotation directions in deepth.

Twenty-two college students (10 males and 12 females), mean age 22, participated in this experiment. Their task was to indicate the rotation directions of 3D SFM by pressing the left (for clockwise CW percept from top view) or the right key of a mouse (for CCW percept) with their left or right thumb. A computer simulated structure-from-motion (a 3D rotating sphere) was created via 30 coherently moving dots with 0.2° diameter each along with an elliptical trajectory of different radii at a mean velocity of 5°/s. The luminant dots were randomly distributed in a spherical area extended 5°×5°. Under unambiguous depth cue condition, dots were fully illuminated in the half of their trajectories and partially illuminated in the other part of the trajectories. The two groups of dots appeared to move in opposite direction. There were two sets of cued rotations in which bright dots (drawing attention) moving leftwards or rightwards. For ambiguous condition (AMB), all dots had equal brightness (averaged luminance of unambiguous displays), which had equal chance to be seen as rotating in either CW or CCW direction. During each experimental trial, after a 500 ms fixation “+”, a rotation-in-depth structure was presented for about 950 ms. A mask of random brighter and dimer dots was displayed for 500 ms after a response window of 1500 ms at the end of each trial.

Advanced eyemovements analysis, e.g. microsaccade rates with directions and time courses, were conducted using methods from Bonneh, Adini & Polat (2015) and Hermens & Walker (2010). The statistical analysis revealed that perceptual judgments of rotation directions under unambiguous cues were faster and more confident than those under the ambiguous conditions. For the micro-saccade, peak velocity and amplitude were higher during perception of unambiguous 3D rotation than those during the ambiguous rotations.There was no significant difference in saccade duration. When participants judged the SFM as rotation of clockwise (left), their microsaccade rate towards left was significantly higher than that towards right and vise versa while the counter-clockwise judgment was made. Under the unambiguous condition, significant differences between CW-cw and CCW-ccw were found during time widows of 150~400 ms and 500~970 ms. In contrast, ambiguous conditions (AMB-cw and AMB-ccw) differed most during 700~950 ms, which indicated extra time of attentional processes.

Our findings of temporal dynamics of the ambiguous and unambiguous perceptual judgments of 3D rotations indicated two stages of processing. First, local speed calculation in three-dimensional structure construction during initial period of 150~200 ms after stimulus onset. Second, visual processing binds local motion vector flows to the overall perceptual judgment of rotation directions. The ambiguous conditions took longer time. When rotations were unambiguous, attentional facilitates during perceptual judgment of 3D rotation of SFM speed up in the higher-level processing.

structure-from-motion (SFM), attention, microsaccade, time course, perceptual grouping

2020-04-14

* 首都師范大學(xué)交叉科學(xué)研究院項(xiàng)目資助。

丁錦紅, E-mail: dingjh@cnu.edu.cn

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