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Visual masking: past accomplishments, present status, future developments.

Breitmeyer BG - Adv Cogn Psychol (2008)

Bottom Line: However, visual masking also has been a phenomenon deemed worthy of study in its own right.Most of the recent uses of visual masking have focused on the study of central processes, particularly those involved in feature, object and scene representations, in attentional control mechanisms, and in phenomenal awareness.Key issues and problems are discussed with the aim of guiding future empirical and theoretical research.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of Houston.

ABSTRACT
Visual masking, throughout its history, has been used as an investigative tool in exploring the temporal dynamics of visual perception, beginning with retinal processes and ending in cortical processes concerned with the conscious registration of stimuli. However, visual masking also has been a phenomenon deemed worthy of study in its own right. Most of the recent uses of visual masking have focused on the study of central processes, particularly those involved in feature, object and scene representations, in attentional control mechanisms, and in phenomenal awareness. In recent years our understanding of the phenomenon and cortical mechanisms of visual masking also has benefited from several brain imaging techniques and from a number of sophisticated and neurophysiologically plausible neural network models. Key issues and problems are discussed with the aim of guiding future empirical and theoretical research.

No MeSH data available.


Related in: MedlinePlus

Multi-unit recordings from upper layers of area V1 of rhesus monkey. Note							as indicated by dashed ovals a) optimal suppression of the early onset							response component at a paracontrast SOA of -100 ms and b) optimal							suppression of the later response component at a metcontrast SOA of 100							ms. (From Macknik &								Livingstone, 1998)
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Figure 2: Multi-unit recordings from upper layers of area V1 of rhesus monkey. Note as indicated by dashed ovals a) optimal suppression of the early onset response component at a paracontrast SOA of -100 ms and b) optimal suppression of the later response component at a metcontrast SOA of 100 ms. (From Macknik & Livingstone, 1998)

Mentions: I believe this view is also consistent with the some of the recent results reported by Macknik and Livingstone (1998). They showed (see Figure 2) that metacontrast suppresses a later target-response component which they associated with the offset of the target, whereas it had virtually no effect on the early response component associated with target onset. In contrast, when a paracontrast mask was applied, powerful suppression of the early response component occurred along with some suppression of the later component. What is one to make of these findings? While other interpretations are clearly possible, my preferred one runs as follows: First, paracontrast exerts its effects primarily on the early feedforward activity and secondarily on the late reentrant activity, since this late activity “feeds on” the feedforward drive. That is to say, since the feedforward drive in V1 is suppressed by paracontrast, the later cortical levels in the feedforward sweep are also activated less; hence the reentrant feedback emanating from them will be weaker, leading also to a suppressed late V1 response component. Second, metacontrast exerts its suppressive effects only on the late, reentrant activity.


Visual masking: past accomplishments, present status, future developments.

Breitmeyer BG - Adv Cogn Psychol (2008)

Multi-unit recordings from upper layers of area V1 of rhesus monkey. Note							as indicated by dashed ovals a) optimal suppression of the early onset							response component at a paracontrast SOA of -100 ms and b) optimal							suppression of the later response component at a metcontrast SOA of 100							ms. (From Macknik &								Livingstone, 1998)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2864971&req=5

Figure 2: Multi-unit recordings from upper layers of area V1 of rhesus monkey. Note as indicated by dashed ovals a) optimal suppression of the early onset response component at a paracontrast SOA of -100 ms and b) optimal suppression of the later response component at a metcontrast SOA of 100 ms. (From Macknik & Livingstone, 1998)
Mentions: I believe this view is also consistent with the some of the recent results reported by Macknik and Livingstone (1998). They showed (see Figure 2) that metacontrast suppresses a later target-response component which they associated with the offset of the target, whereas it had virtually no effect on the early response component associated with target onset. In contrast, when a paracontrast mask was applied, powerful suppression of the early response component occurred along with some suppression of the later component. What is one to make of these findings? While other interpretations are clearly possible, my preferred one runs as follows: First, paracontrast exerts its effects primarily on the early feedforward activity and secondarily on the late reentrant activity, since this late activity “feeds on” the feedforward drive. That is to say, since the feedforward drive in V1 is suppressed by paracontrast, the later cortical levels in the feedforward sweep are also activated less; hence the reentrant feedback emanating from them will be weaker, leading also to a suppressed late V1 response component. Second, metacontrast exerts its suppressive effects only on the late, reentrant activity.

Bottom Line: However, visual masking also has been a phenomenon deemed worthy of study in its own right.Most of the recent uses of visual masking have focused on the study of central processes, particularly those involved in feature, object and scene representations, in attentional control mechanisms, and in phenomenal awareness.Key issues and problems are discussed with the aim of guiding future empirical and theoretical research.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology, University of Houston.

ABSTRACT
Visual masking, throughout its history, has been used as an investigative tool in exploring the temporal dynamics of visual perception, beginning with retinal processes and ending in cortical processes concerned with the conscious registration of stimuli. However, visual masking also has been a phenomenon deemed worthy of study in its own right. Most of the recent uses of visual masking have focused on the study of central processes, particularly those involved in feature, object and scene representations, in attentional control mechanisms, and in phenomenal awareness. In recent years our understanding of the phenomenon and cortical mechanisms of visual masking also has benefited from several brain imaging techniques and from a number of sophisticated and neurophysiologically plausible neural network models. Key issues and problems are discussed with the aim of guiding future empirical and theoretical research.

No MeSH data available.


Related in: MedlinePlus