The Experts below are selected from a list of 9219 Experts worldwide ranked by ideXlab platform
Jim Mintz - One of the best experts on this subject based on the ideXlab platform.
-
forward and backward Visual Masking in unaffected siblings of schizophrenic patients
Biological Psychiatry, 2006Co-Authors: Michael F. Green, Keith H. Nuechterlein, Bruno G. Breitmeyer, Jim MintzAbstract:Background Visual Masking tasks assess the earliest stages of Visual processing. This study examined Visual Masking performance for forward and backward Masking tasks in siblings of schizophrenic patients and healthy comparison subjects. Methods A staircase method was used to ensure that unmasked target identification was equivalent across subjects to eliminate differences due to discrimination of simple perceptual inputs. Four computerized Visual Masking tasks were administered to 43 siblings of patients and 42 normal comparison subjects. The tasks included: 1) locating a target; 2) identifying a target with a high-energy mask; 3) identifying a target with a low-energy mask; and 4) a paracontrast/metacontrast procedure with nonoverlapping target and mask. Results Across Masking conditions, there was a significant group by forward/backward interaction, meaning that siblings showed a larger difference from control subjects in backward versus forward Masking. This group difference was more pronounced in the location condition. Conclusions These results support the theory that Visual Masking procedures may be indicators of vulnerability to schizophrenia. The pattern of findings in this report (larger group differences on backward versus forward Masking and on the location condition) suggests that the activity of transient Visual channels may be particularly linked to vulnerability.
-
Modulation of Attention During Visual Masking in Schizophrenia
American Journal of Psychiatry, 2005Co-Authors: Yuri Rassovsky, Michael F. Green, Keith H. Nuechterlein, Bruno G. Breitmeyer, Jim MintzAbstract:OBJECTIVE: Schizophrenia patients consistently demonstrate performance deficits on Visual Masking procedures. The present study examined whether attentional manipulation would improve subjects’ performance on Visual Masking. METHOD: A metacontrast task was administered to 105 schizophrenia patients and 52 healthy comparison subjects. Attention was manipulated by associating selected trials of the task with monetary reward. RESULTS: Schizophrenia patients exhibited poorer performance than the comparison subjects across conditions. Patients demonstrated modest, but statistically significant, improvement in performance with the attentional manipulation. This improvement was not significant for the comparison subjects. CONCLUSIONS: These findings suggest that early Visual processes in schizophrenia are responsive to attentional manipulation but that the degree of improvement is relatively small, suggesting that these processes are not easily altered.
-
Visual processing in schizophrenia: Structural equation modeling of Visual Masking performance.
Schizophrenia Research, 2005Co-Authors: Yuri Rassovsky, Michael F. Green, Keith H. Nuechterlein, Bruno G. Breitmeyer, Jim MintzAbstract:Schizophrenic patients consistently demonstrate performance deficits on Visual Masking procedures. In Visual Masking, the subject's ability to process a target stimulus is reduced by another stimulus (mask) presented either before (forward Masking) or after (backward Masking) the target. Masking procedures employed in schizophrenia research have used several experimental paradigms. Most early studies have used high-energy masks (i.e., the mask is stronger than the target) and spatially overlapping target and mask. More recently, studies have begun to employ relatively weak (i.e., low-energy) masks, as well as masks that surround, but do not spatially overlap, the target. Data for forward and backward Masking components of four Masking conditions (target location and identification with a high-energy mask, target identification with a low-energy mask, and target identification with equal energy paracontrast/metacontrast) were collected from 75 patients with schizophrenia. Based on theoretical distinctions among Masking procedures, we compared four models of Visual Masking using structural equation modeling. Although high zero-order correlations were found among the Masking parameters, a four-factor model, in which factors were separated on the type of response (target location and identification), the shape of the function (monotonic and non-monotonic), and the overlap of the stimuli (overlapping and non-overlapping), provided the best fit for the data. These findings suggest that the four Masking procedures used in this study may tap unique aspects of Visual processing and are not redundant. The results also support theories of the different mechanisms underlying performance on these measures.
-
Paracontrast and metacontrast in schizophrenia: clarifying the mechanism for Visual Masking deficits
Schizophrenia Research, 2004Co-Authors: Yuri Rassovsky, Michael F. Green, Keith H. Nuechterlein, Bruno G. Breitmeyer, Jim MintzAbstract:Schizophrenic patients consistently demonstrate performance deficits on Visual Masking procedures. Visual Masking can occur through two distinctly different mechanisms: interruption and integration. One highly effective way to limit the Masking mechanism to interruption is to use a mask that surrounds, but does not spatially overlap, the target. These procedures are called paracontrast and metacontrast (for forward and backward Masking, respectively). Despite their clear advantages for interpretation, paracontrast and metacontrast have not been used previously in schizophrenia. In the present study, we examined the reliability of the paracontrast and metacontrast procedures by administering these tasks to 103 schizophrenic patients and 49 normal control subjects. In addition, we compared the results to those from a low-energy Masking condition, which is an alternative way to limit Masking to interruption. Patients showed deficits on both the paracontrast and metacontrast procedures. The deficits in paracontrast and metacontrast were comparable to those seen previously with low-energy Masking. These results suggest that the paracontrast/metacontrast procedure and the procedure using a low-energy mask are roughly equally sensitive to deficits in early Visual processing among schizophrenic patients. These results bolster previous conclusions that schizophrenic patients show deficits on Visual Masking tasks even when Masking on those tasks occurs entirely through the interruption mechanism.
-
forward and backward Visual Masking in schizophrenia influence of age
Psychological Medicine, 2003Co-Authors: Michael F. Green, Keith H. Nuechterlein, Bruno G. Breitmeyer, Jim Mintz, John TsuangAbstract:Background. Visual Masking tasks assess the earliest stages of Visual processing. This study was conducted to address: (1) whether schizophrenia patients show Masking deficits after controlling for sensory input factors; (2) whether patients have relatively intact forward Masking (when the mask precedes the target) compared with backward Masking (when the mask follows the target); and (3) whether the Masking deficits in schizophrenia reflect an accelerated age-related decline in performance. Method. A staircase method was used to ensure that the unmasked target identification was equivalent across subjects to eliminate any confounding due to differences in discrimination of simple perceptual inputs. Three computerized Visual Masking tasks were administered to 120 schizophrenia patients (ages 18–56) and 55 normal comparison subjects (ages 19–54) under both forward and backward Masking conditions. The tasks included: (1) locating a target; (2) identifying a target with a high-energy mask; and (3) identifying a target with a low-energy mask. Results. Patients showed deficits across all three Masking tasks. Interactions of group by forward versus backward Masking were not significant, suggesting that deficits in forward and backward Masking were comparable. All three conditions showed an age-related decline in performance and rates of decline were comparable between patients and controls. Two of the Masking conditions showed increased rates of decline in backward, compared to forward, Masking. Conclusions. We found age-related decline in performance that was comparable for the two groups. In addition, we failed to find evidence of a relative sparing of forward Masking in schizophrenia. These results suggest that: (1) early Visual processing deficits in schizophrenia are not due to a simple perceptual input problem; (2) sustained channels are involved in the Masking deficit (in addition to transient channels); and (3) for the age range in this study, these deficits in schizophrenia are not age-related.
Michael F. Green - One of the best experts on this subject based on the ideXlab platform.
-
Visual Masking in Schizophrenia: Overview and Theoretical Implications
Schizophrenia Bulletin, 2011Co-Authors: Michael F. Green, Junghee Lee, Jonathan K. Wynn, Kristopher I. MathisAbstract:Visual Masking provides several key advantages for exploring the earliest stages of Visual processing in schizophrenia: it allows for control over timing at the millisecond level, there are several well-supported theories of the underlying neurobiology of Visual Masking, and it is amenable to examination by electroencephalogram (EEG) and functional magnetic resonance imaging (fMRI). In this paper, we provide an overview of the Visual Masking impairment schizophrenia, including the relevant theoretical mechanisms for Masking impairment. We will discuss its relationship to clinical symptoms, antipsychotic medications, diagnostic specificity, and presence in at-risk populations. As part of this overview, we will cover the neural correlates of Visual Masking based on recent findings from EEG and fMRI. Finally, we will suggest a possible mechanism that could explain the patterns of Masking findings and other Visual processing findings in schizophrenia.
-
Visual Masking by object substitution in schizophrenia.
Psychological Medicine, 2010Co-Authors: Michael F. Green, Bruno G. Breitmeyer, Jonathan K. Wynn, Kristopher I. Mathis, Keith H. NuechterleinAbstract:Background Schizophrenia patients demonstrate impairment on Visual backward Masking, a measure of early Visual processing. Most Visual Masking paradigms involve two distinct processes, an early fast-acting component associated with object formation and a later component that acts through object substitution. So far, Masking paradigms used in schizophrenia research have been unable to separate these two processes. Method We administered three Visual processing paradigms (location Masking with forward and backward Masking, four-dot backward Masking and a cuing task) to 136 patients with schizophrenia or schizoaffective disorder and 79 healthy controls. A psychophysical procedure was used to match subjects on identification of an unmasked target prior to location Masking. Location Masking interrupts object formation, four-dot Masking task works through Masking by object substitution and the cuing task measures iconic decay. Results Patients showed impairment on location Masking after being matched for input threshold, similar to previous reports. After correcting for age, patients showed lower performance on four-dot Masking than controls, but the groups did not differ on the cuing task. Conclusions Patients with schizophrenia showed lower performance when Masking was specific to object substitution. The difference in object substitution Masking was not due to a difference in rate of iconic decay, which was comparable in the two groups. These results suggest that, despite normal iconic decay rates, individuals with schizophrenia show impairment in a paradigm of Masking by object substitution that did not also involve disruption of object formation.
-
Functional neuroanatomy of Visual Masking deficits in schizophrenia
Archives of General Psychiatry, 2009Co-Authors: Michael F. Green, Keith H. Nuechterlein, Junghee Lee, Jonathan K. Wynn, Mark S. Cohen, Stephen A. Engel, Alexander S. Korb, David C. GlahnAbstract:Context: Visual Masking procedures assess the earliest stages of Visual processing. Patients with schizophrenia reliably show deficits on Visual Masking, and these procedures have been used to explore vulnerability to schizophrenia, probe underlying neural circuits, and help explain functional outcome. Objective: To identify and compare regional brain activity associated with one form of Visual Masking (ie, backward Masking) in schizophrenic patients and healthy controls. Design: Subjects received functional magnetic resonance imaging scans. While in the scanner, subjects performed a backward Masking task and were given 3 functional localizer activation scans to identify early Visual processing regions of interest (ROIs).
-
Stability of Visual Masking performance in recent-onset schizophrenia: an 18-month longitudinal study.
Schizophrenia Research, 2008Co-Authors: Junghee Lee, Keith H. Nuechterlein, Kenneth L Subotnik, Catherine A Sugar, Joseph Ventura, Denise Gretchen-doorly, Kimberly Kelly, Michael F. GreenAbstract:Visual Masking deficit in schizophrenia has been suggested to be a potential vulnerability marker for schizophrenia. An important characteristic of a vulnerability marker is stability over time, but relatively little is known about the longitudinal course of Masking performance of schizophrenia patients. In this study, we examined the stability of Visual Masking performance in recent-onset schizophrenia patients over an 18-month period. We administered both forward and backward Masking trials with multiple stimulus onset asynchronies for four Masking conditions at three time points (baseline, 6-month, and 18-month). Recent-onset schizophrenia patients showed stable Masking performance for both forward and backward conditions over a period of 18 months. Furthermore, the stable performance was observed across all four Masking conditions. The findings of this study provide further support for the view that Visual Masking deficits reflect a possible vulnerability marker for schizophrenia.
-
forward and backward Visual Masking in unaffected siblings of schizophrenic patients
Biological Psychiatry, 2006Co-Authors: Michael F. Green, Keith H. Nuechterlein, Bruno G. Breitmeyer, Jim MintzAbstract:Background Visual Masking tasks assess the earliest stages of Visual processing. This study examined Visual Masking performance for forward and backward Masking tasks in siblings of schizophrenic patients and healthy comparison subjects. Methods A staircase method was used to ensure that unmasked target identification was equivalent across subjects to eliminate differences due to discrimination of simple perceptual inputs. Four computerized Visual Masking tasks were administered to 43 siblings of patients and 42 normal comparison subjects. The tasks included: 1) locating a target; 2) identifying a target with a high-energy mask; 3) identifying a target with a low-energy mask; and 4) a paracontrast/metacontrast procedure with nonoverlapping target and mask. Results Across Masking conditions, there was a significant group by forward/backward interaction, meaning that siblings showed a larger difference from control subjects in backward versus forward Masking. This group difference was more pronounced in the location condition. Conclusions These results support the theory that Visual Masking procedures may be indicators of vulnerability to schizophrenia. The pattern of findings in this report (larger group differences on backward versus forward Masking and on the location condition) suggests that the activity of transient Visual channels may be particularly linked to vulnerability.
Keith H. Nuechterlein - One of the best experts on this subject based on the ideXlab platform.
-
Visual Masking by object substitution in schizophrenia.
Psychological Medicine, 2010Co-Authors: Michael F. Green, Bruno G. Breitmeyer, Jonathan K. Wynn, Kristopher I. Mathis, Keith H. NuechterleinAbstract:Background Schizophrenia patients demonstrate impairment on Visual backward Masking, a measure of early Visual processing. Most Visual Masking paradigms involve two distinct processes, an early fast-acting component associated with object formation and a later component that acts through object substitution. So far, Masking paradigms used in schizophrenia research have been unable to separate these two processes. Method We administered three Visual processing paradigms (location Masking with forward and backward Masking, four-dot backward Masking and a cuing task) to 136 patients with schizophrenia or schizoaffective disorder and 79 healthy controls. A psychophysical procedure was used to match subjects on identification of an unmasked target prior to location Masking. Location Masking interrupts object formation, four-dot Masking task works through Masking by object substitution and the cuing task measures iconic decay. Results Patients showed impairment on location Masking after being matched for input threshold, similar to previous reports. After correcting for age, patients showed lower performance on four-dot Masking than controls, but the groups did not differ on the cuing task. Conclusions Patients with schizophrenia showed lower performance when Masking was specific to object substitution. The difference in object substitution Masking was not due to a difference in rate of iconic decay, which was comparable in the two groups. These results suggest that, despite normal iconic decay rates, individuals with schizophrenia show impairment in a paradigm of Masking by object substitution that did not also involve disruption of object formation.
-
Functional neuroanatomy of Visual Masking deficits in schizophrenia
Archives of General Psychiatry, 2009Co-Authors: Michael F. Green, Keith H. Nuechterlein, Junghee Lee, Jonathan K. Wynn, Mark S. Cohen, Stephen A. Engel, Alexander S. Korb, David C. GlahnAbstract:Context: Visual Masking procedures assess the earliest stages of Visual processing. Patients with schizophrenia reliably show deficits on Visual Masking, and these procedures have been used to explore vulnerability to schizophrenia, probe underlying neural circuits, and help explain functional outcome. Objective: To identify and compare regional brain activity associated with one form of Visual Masking (ie, backward Masking) in schizophrenic patients and healthy controls. Design: Subjects received functional magnetic resonance imaging scans. While in the scanner, subjects performed a backward Masking task and were given 3 functional localizer activation scans to identify early Visual processing regions of interest (ROIs).
-
Stability of Visual Masking performance in recent-onset schizophrenia: an 18-month longitudinal study.
Schizophrenia Research, 2008Co-Authors: Junghee Lee, Keith H. Nuechterlein, Kenneth L Subotnik, Catherine A Sugar, Joseph Ventura, Denise Gretchen-doorly, Kimberly Kelly, Michael F. GreenAbstract:Visual Masking deficit in schizophrenia has been suggested to be a potential vulnerability marker for schizophrenia. An important characteristic of a vulnerability marker is stability over time, but relatively little is known about the longitudinal course of Masking performance of schizophrenia patients. In this study, we examined the stability of Visual Masking performance in recent-onset schizophrenia patients over an 18-month period. We administered both forward and backward Masking trials with multiple stimulus onset asynchronies for four Masking conditions at three time points (baseline, 6-month, and 18-month). Recent-onset schizophrenia patients showed stable Masking performance for both forward and backward conditions over a period of 18 months. Furthermore, the stable performance was observed across all four Masking conditions. The findings of this study provide further support for the view that Visual Masking deficits reflect a possible vulnerability marker for schizophrenia.
-
forward and backward Visual Masking in unaffected siblings of schizophrenic patients
Biological Psychiatry, 2006Co-Authors: Michael F. Green, Keith H. Nuechterlein, Bruno G. Breitmeyer, Jim MintzAbstract:Background Visual Masking tasks assess the earliest stages of Visual processing. This study examined Visual Masking performance for forward and backward Masking tasks in siblings of schizophrenic patients and healthy comparison subjects. Methods A staircase method was used to ensure that unmasked target identification was equivalent across subjects to eliminate differences due to discrimination of simple perceptual inputs. Four computerized Visual Masking tasks were administered to 43 siblings of patients and 42 normal comparison subjects. The tasks included: 1) locating a target; 2) identifying a target with a high-energy mask; 3) identifying a target with a low-energy mask; and 4) a paracontrast/metacontrast procedure with nonoverlapping target and mask. Results Across Masking conditions, there was a significant group by forward/backward interaction, meaning that siblings showed a larger difference from control subjects in backward versus forward Masking. This group difference was more pronounced in the location condition. Conclusions These results support the theory that Visual Masking procedures may be indicators of vulnerability to schizophrenia. The pattern of findings in this report (larger group differences on backward versus forward Masking and on the location condition) suggests that the activity of transient Visual channels may be particularly linked to vulnerability.
-
Modulation of Attention During Visual Masking in Schizophrenia
American Journal of Psychiatry, 2005Co-Authors: Yuri Rassovsky, Michael F. Green, Keith H. Nuechterlein, Bruno G. Breitmeyer, Jim MintzAbstract:OBJECTIVE: Schizophrenia patients consistently demonstrate performance deficits on Visual Masking procedures. The present study examined whether attentional manipulation would improve subjects’ performance on Visual Masking. METHOD: A metacontrast task was administered to 105 schizophrenia patients and 52 healthy comparison subjects. Attention was manipulated by associating selected trials of the task with monetary reward. RESULTS: Schizophrenia patients exhibited poorer performance than the comparison subjects across conditions. Patients demonstrated modest, but statistically significant, improvement in performance with the attentional manipulation. This improvement was not significant for the comparison subjects. CONCLUSIONS: These findings suggest that early Visual processes in schizophrenia are responsive to attentional manipulation but that the degree of improvement is relatively small, suggesting that these processes are not easily altered.
Bruno G. Breitmeyer - One of the best experts on this subject based on the ideXlab platform.
-
A statistical perspective to Visual Masking
Vision Research, 2015Co-Authors: Sevda Agaoglu, Bruno G. Breitmeyer, Mehmet N. Agaoglu, Haluk OgmenAbstract:A stimulus (mask) reduces the visibility of another stimulus (target) when they are presented in close spatio-temporal vicinity of each other, a phenomenon called Visual Masking. Visual Masking has been extensively studied to understand dynamics of information processing in the Visual system. In this study, we adopted a statistical point of view, rather than a mechanistic one, to investigate how mask-related activities might influence target-related ones within the context of Visual Masking. We modeled the distribution of response errors of human observers in three different Visual Masking experiments, namely para-/meta-contrast Masking, pattern Masking by noise, and pattern Masking by structure. We adopted statistical models, which have been used previously in studies of Visual short-term memory, to capture response characteristics of observers under Masking conditions. We tested the following scenarios: (i) mask activity may reduce a target’s signal-to-noise ratio (SNR) without interfering with its encoding precision. (ii) Mask activity may ‘‘interfere” with the encoding of a target and cause decreased precision in observer’s reports. (iii) Decreased performance due to Masking may result from the confusion or ‘‘misbinding” of a mask’s features with those of the target, when they are similar as in the case of pattern Masking by structure. Our results show that in all three types of Masking, the reduction of a target’s SNR was the primary process whereby Masking occurred. A significant decrease, correlated with Masking strength, in the precision of the target’s encoding was observed in para-/meta-contrast and pattern Masking by structure, but not in pattern Masking by noise. We interpret these findings as the mask reducing the target’s SNR (i) by suppressing or interrupting the signal of the target in para-/meta-contrast, (ii) by increasing noise in pattern Masking by noise, and (iii) a combination of the two in pattern Masking by structure.
-
Visual Masking by object substitution in schizophrenia.
Psychological Medicine, 2010Co-Authors: Michael F. Green, Bruno G. Breitmeyer, Jonathan K. Wynn, Kristopher I. Mathis, Keith H. NuechterleinAbstract:Background Schizophrenia patients demonstrate impairment on Visual backward Masking, a measure of early Visual processing. Most Visual Masking paradigms involve two distinct processes, an early fast-acting component associated with object formation and a later component that acts through object substitution. So far, Masking paradigms used in schizophrenia research have been unable to separate these two processes. Method We administered three Visual processing paradigms (location Masking with forward and backward Masking, four-dot backward Masking and a cuing task) to 136 patients with schizophrenia or schizoaffective disorder and 79 healthy controls. A psychophysical procedure was used to match subjects on identification of an unmasked target prior to location Masking. Location Masking interrupts object formation, four-dot Masking task works through Masking by object substitution and the cuing task measures iconic decay. Results Patients showed impairment on location Masking after being matched for input threshold, similar to previous reports. After correcting for age, patients showed lower performance on four-dot Masking than controls, but the groups did not differ on the cuing task. Conclusions Patients with schizophrenia showed lower performance when Masking was specific to object substitution. The difference in object substitution Masking was not due to a difference in rate of iconic decay, which was comparable in the two groups. These results suggest that, despite normal iconic decay rates, individuals with schizophrenia show impairment in a paradigm of Masking by object substitution that did not also involve disruption of object formation.
-
Visual Masking: past accomplishments, present status, future developments.
Advances in cognitive psychology, 2008Co-Authors: Bruno G. BreitmeyerAbstract: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.
-
Visual Masking time slices through conscious and unconscious vision
2006Co-Authors: Bruno G. Breitmeyer, Haluk OgmenAbstract:1. A history of Visual Masking 2. Methods, applications, and findings in Visual pattern Masking 3. Neurobiological correlates of Visual pattern Masking 4. Models and mechanisms of Visual Masking: a selective review and comparison 5. The sustained-transient approach to Visual Masking: an updated model 6. Metacontrast and motion perception 7. Figural context and attention in Visual Masking 8. Unconscious processing revealed by Visual Masking 9. Visual Masking in select subject populations 10. Epilogue
-
forward and backward Visual Masking in unaffected siblings of schizophrenic patients
Biological Psychiatry, 2006Co-Authors: Michael F. Green, Keith H. Nuechterlein, Bruno G. Breitmeyer, Jim MintzAbstract:Background Visual Masking tasks assess the earliest stages of Visual processing. This study examined Visual Masking performance for forward and backward Masking tasks in siblings of schizophrenic patients and healthy comparison subjects. Methods A staircase method was used to ensure that unmasked target identification was equivalent across subjects to eliminate differences due to discrimination of simple perceptual inputs. Four computerized Visual Masking tasks were administered to 43 siblings of patients and 42 normal comparison subjects. The tasks included: 1) locating a target; 2) identifying a target with a high-energy mask; 3) identifying a target with a low-energy mask; and 4) a paracontrast/metacontrast procedure with nonoverlapping target and mask. Results Across Masking conditions, there was a significant group by forward/backward interaction, meaning that siblings showed a larger difference from control subjects in backward versus forward Masking. This group difference was more pronounced in the location condition. Conclusions These results support the theory that Visual Masking procedures may be indicators of vulnerability to schizophrenia. The pattern of findings in this report (larger group differences on backward versus forward Masking and on the location condition) suggests that the activity of transient Visual channels may be particularly linked to vulnerability.
Vincent Di Lollo - One of the best experts on this subject based on the ideXlab platform.
-
what s new in Visual Masking
Trends in Cognitive Sciences, 2000Co-Authors: James T. Enns, Vincent Di LolloAbstract:A brief display that is clearly visible when shown alone can be rendered invisible by the subsequent presentation of a second Visual stimulus. Several recently described backward Masking effects are not predicted by current theories of Visual Masking, including Masking by four small dots that surround (but do not touch) a target object and Masking by a surrounding object that remains on display after the target object has been turned off. A crucial factor in both of these effects is attention: almost no Masking occurs if attention can be rapidly focused on the target, whereas powerful Masking ensues if attention directed at the target is delayed. A new theory of Visual Masking, inspired by developments in neuroscience, can account for these effects, as well as more traditional Masking effects. In addition, the new theory sheds light on related research, such as the attentional blink, inattentional blindness and change blindness.
-
What’s new in Visual Masking?
Trends in Cognitive Sciences, 2000Co-Authors: James T. Enns, Vincent Di LolloAbstract:A brief display that is clearly visible when shown alone can be rendered invisible by the subsequent presentation of a second Visual stimulus. Several recently described backward Masking effects are not predicted by current theories of Visual Masking, including Masking by four small dots that surround (but do not touch) a target object and Masking by a surrounding object that remains on display after the target object has been turned off. A crucial factor in both of these effects is attention: almost no Masking occurs if attention can be rapidly focused on the target, whereas powerful Masking ensues if attention directed at the target is delayed. A new theory of Visual Masking, inspired by developments in neuroscience, can account for these effects, as well as more traditional Masking effects. In addition, the new theory sheds light on related research, such as the attentional blink, inattentional blindness and change blindness.
-
Visual Masking plays two roles in the attentional blink.
Perception & Psychophysics, 1999Co-Authors: Jamie C. Brehaut, James T. Enns, Vincent Di LolloAbstract:When two targets are displayed in rapid Visual sequence and masked by trailing patterns, identification accuracy is nearly perfect for the first target but follows a U-shaped pattern over temporal lag for the second target. Three experiments examined the role of Visual Masking in this attentional blink. Experiment 1 compared integration and interruption masks for both targets. Although either mask was effective in producing the blink when applied to the first target, only the interruption mask was effective when applied to the second target. Experiment 2 showed that integration Masking of the second target was ineffective over a wide range of accuracy levels. Combining the two forms of Masking in Experiment 3 confirmed the dissociation: A combined mask had only a main effect on accuracy for the first target, whereas it produced a qualitatively different pattern over temporal lag for the second target. These results suggest that representations of the target are substituted in consciousness by that of the interruption mask when Visual attention is preoccupied.
