General precedes specific in memory representations for structured experience.

Abstract The hollow-mask illusion is an optical illusion where a concave face is perceived as convex. It has been demonstrated that individuals with schizophrenia and anxiety are less susceptible to the illusion than controls. Previous research has shown that the P300 and P600 event-related potentials (ERPs) are affected in individuals with schizophrenia. Here, we examined whether individual differences in neuroticism and anxiety scores, traits that have been suggested to be risk factors for schizophrenia and anxiety disorders, affect ERPs of healthy participants while they view concave faces. Our results confirm that the participants were susceptible to the illusion, misperceiving concave faces as convex. We additionally demonstrate significant interactions of the concave condition with state anxiety in central and parietal electrodes for P300 and parietal areas for P600, but not with neuroticism and trait anxiety. The state anxiety interactions were driven by low-state anxiety participants showing lower amplitudes for concave faces compared to convex. The P300 and P600 amplitudes were smaller when a concave face activated a convex face memory representation, since the stimulus did not match the active representation. The opposite pattern was evident in high-state anxiety participants in regard to state anxiety interaction and the hollow-mask illusion, demonstrating larger P300 and P600 amplitudes to concave faces suggesting impaired late information processing in this group. This could be explained by impaired allocation of attentional resources in high-state anxiety leading to hyperarousal to concave faces that are unexpected mismatches to standard memory representations, as opposed to expected convex faces.

Download Full-text

Vision and the representation of the surroundings in spatial memory

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2010.0188 ◽

2011 ◽

Vol 366 (1564) ◽

pp. 596-610 ◽

Cited By ~ 50

Author(s):

Benjamin W. Tatler ◽

Michael F. Land

Keyword(s):

Spatial Memory ◽

Visual Environment ◽

Coding Scheme ◽

Perceptual Stability ◽

The World ◽

Scene Viewing ◽

Memory Representations ◽

The Brain ◽

Allocentric Representations ◽

And Task

One of the paradoxes of vision is that the world as it appears to us and the image on the retina at any moment are not much like each other. The visual world seems to be extensive and continuous across time. However, the manner in which we sample the visual environment is neither extensive nor continuous. How does the brain reconcile these differences? Here, we consider existing evidence from both static and dynamic viewing paradigms together with the logical requirements of any representational scheme that would be able to support active behaviour. While static scene viewing paradigms favour extensive, but perhaps abstracted, memory representations, dynamic settings suggest sparser and task-selective representation. We suggest that in dynamic settings where movement within extended environments is required to complete a task, the combination of visual input, egocentric and allocentric representations work together to allow efficient behaviour. The egocentric model serves as a coding scheme in which actions can be planned, but also offers a potential means of providing the perceptual stability that we experience.

Download Full-text

Intact Priming for Novel Perceptual Representations in Amnesia

Journal of Cognitive Neuroscience ◽

10.1162/jocn.1997.9.6.699 ◽

1997 ◽

Vol 9 (6) ◽

pp. 699-713 ◽

Cited By ~ 20

Author(s):

Stephan B. Hamann ◽

Larry R. Squire

Keyword(s):

Recognition Memory ◽

Declarative Memory ◽

Brain Structures ◽

Perceptual Identification ◽

Single Exposure ◽

Memory Representations ◽

Perceptual Representations ◽

The Creation ◽

And Control ◽

The Brain

Recent studies have challenged the notion that priming for ostensibly novel stimuli such as pseudowords (REAB) reflects the creation of new representations. Priming for such stimuli could instead reflect the activation of familiar memory representations that are orthographically similar (READ) and/or the activation of subparts of stimuli (RE, EX, AR), which are familar because they occur commonly in English. We addressed this issue in three experiments that assessed perceptual identification priming and recognition memory for novel and familiar letter strings in amnesic patients and control subjects. Priming for words, pseudowords, and orthographically illegal nonwords was fully intact in the amnesic patients following a single exposure, whereas recognition memory was impaired for the same items. Thus, priming can occur for stimuli that are unlikely to have preexisting representations. Words and pseudowords exhibited twice as much priming as illegal nonwords, suggesting that activation may contribute to priming for words and wordlike stimuli. Additional results showed that priming for illegal nonwords resulted from the formation of new perceptual associations among the component letters of each nonword rather than the activation of individual letter representations. In summary, the results demonstrate that priming following a single exposure can depend on the creation of new perceptual representations and that such priming is independent of the brain structures essential for declarative memory.

Download Full-text