東華大學圖書館 |

語系: 繁體中文

說明(常見問題)

回圖書館首頁

手機版館藏查詢

登入

回首頁

切換: 標籤 | MARC模式 | ISBD

Feature-based Attentional Gain is Fl...

Scolari, Miranda Rose.

FindBook

Google Book

Amazon

博客來

Feature-based Attentional Gain is Flexibly Deployed in Visual Cortex.

紀錄類型:	書目-語言資料,印刷品 : Monograph/item
正題名/作者:	Feature-based Attentional Gain is Flexibly Deployed in Visual Cortex./
作者:	Scolari, Miranda Rose.
面頁冊數:	167 p.
附註:	Source: Dissertation Abstracts International, Volume: 73-08(E), Section: B.
Contained By:	Dissertation Abstracts International73-08B(E).
標題:	Psychology, General. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3505008
ISBN:	9781267288660

Feature-based Attentional Gain is Flexibly Deployed in Visual Cortex.
Scolari, Miranda Rose.

Feature-based Attentional Gain is Flexibly Deployed in Visual Cortex. - 167 p.

Source: Dissertation Abstracts International, Volume: 73-08(E), Section: B.

Thesis (Ph.D.)--University of California, San Diego, 2012.

Feature-based attention (FBA) is a selection mechanism implemented in the visual system that facilitates perceptual representations of behaviorally-relevant stimulus features at the expense of behaviorally-irrelevant features in order to aid decision-making. Traditional accounts of FBA indicate that this facilitation occurs via the modulation of feature-selective neurons in visual cortex: the responses of neurons that are maximally driven by (or "tuned to") the relevant feature are enhanced (termed sensory gain or attentional gain), while the responses of other neurons are suppressed. However, recent theoretical and psychophysical evidence suggests potential modifications to this longstanding model, wherein the locus of attentional gain depends not only on the shape of the neuronal tuning functions, but also on the nature of the perceptual task. For example, during a coarse discrimination task, in which an observer must discriminate a target feature (e.g., 90° oriented line) from a set of highly dissimilar distractors (e.g., 180° oriented line), neurons tuned to the target (termed on-channel or on-target neurons) are highly informative given a large change in firing rates between stimulus alternatives (i.e., greater signal-to-noise ratio or SNR). During a fine discrimination task, however, in which the target and distractors are highly similar (e.g., 90° oriented line among 85° oriented lines), on-channel neurons provide little sensory evidence since they respond nearly as well to both the target and distractors. In this case, attentional gain should be applied to neurons tuned away from the target feature (interchangeably termed off-channel or off-target neurons) that produce a greater SNR. Here, I present a set of psychophysical (Chapter 1) and neuroimaging (Chapters 2 and 3) studies in support of an optimal gain model of FBA that flexibly targets sensory inputs based on informativeness. Together, the studies suggest that human observers are able to optimally deploy attentional gain according to task demands to feature-selective populations in visual cortex. Furthermore, the level of off-channel modulation is predictive of subjects' behavioral performance on a range of difficult fine discrimination tasks, indicating that these inputs are ultimately utilized in perceptual decision-making.

ISBN: 9781267288660Subjects--Topical Terms:

1018034
Psychology, General.

Feature-based Attentional Gain is Flexibly Deployed in Visual Cortex.
LDR:03251nam a2200289 4500 001 1966594
005 20141112075020.5
008 150210s2012 ||||||||||||||||| ||eng d
020 $a 9781267288660
035 $a (MiAaPQ)AAI3505008
035 $a AAI3505008
040 $a MiAaPQ $c MiAaPQ
100 1 $a Scolari, Miranda Rose. $3 2103430
245 1 0 $a Feature-based Attentional Gain is Flexibly Deployed in Visual Cortex.
300 $a 167 p.
500 $a Source: Dissertation Abstracts International, Volume: 73-08(E), Section: B.
500 $a Adviser: John T. Serences.
502 $a Thesis (Ph.D.)--University of California, San Diego, 2012.
520 $a Feature-based attention (FBA) is a selection mechanism implemented in the visual system that facilitates perceptual representations of behaviorally-relevant stimulus features at the expense of behaviorally-irrelevant features in order to aid decision-making. Traditional accounts of FBA indicate that this facilitation occurs via the modulation of feature-selective neurons in visual cortex: the responses of neurons that are maximally driven by (or "tuned to") the relevant feature are enhanced (termed sensory gain or attentional gain), while the responses of other neurons are suppressed. However, recent theoretical and psychophysical evidence suggests potential modifications to this longstanding model, wherein the locus of attentional gain depends not only on the shape of the neuronal tuning functions, but also on the nature of the perceptual task. For example, during a coarse discrimination task, in which an observer must discriminate a target feature (e.g., 90° oriented line) from a set of highly dissimilar distractors (e.g., 180° oriented line), neurons tuned to the target (termed on-channel or on-target neurons) are highly informative given a large change in firing rates between stimulus alternatives (i.e., greater signal-to-noise ratio or SNR). During a fine discrimination task, however, in which the target and distractors are highly similar (e.g., 90° oriented line among 85° oriented lines), on-channel neurons provide little sensory evidence since they respond nearly as well to both the target and distractors. In this case, attentional gain should be applied to neurons tuned away from the target feature (interchangeably termed off-channel or off-target neurons) that produce a greater SNR. Here, I present a set of psychophysical (Chapter 1) and neuroimaging (Chapters 2 and 3) studies in support of an optimal gain model of FBA that flexibly targets sensory inputs based on informativeness. Together, the studies suggest that human observers are able to optimally deploy attentional gain according to task demands to feature-selective populations in visual cortex. Furthermore, the level of off-channel modulation is predictive of subjects' behavioral performance on a range of difficult fine discrimination tasks, indicating that these inputs are ultimately utilized in perceptual decision-making.
590 $a School code: 0033.
650 4 $a Psychology, General. $3 1018034
650 4 $a Psychology, Cognitive. $3 1017810
650 4 $a Biology, Neuroscience. $3 1017680
690 $a 0621
690 $a 0633
690 $a 0317
710 2 $a University of California, San Diego. $b Psychology. $3 1675458
773 0 $t Dissertation Abstracts International $g 73-08B(E).
790 $a 0033
791 $a Ph.D.
792 $a 2012
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3505008