Global Semantic Expectancy and Language Comprehension

1994 ◽  
Vol 6 (1) ◽  
pp. 70-83 ◽  
Author(s):  
Marie St. George ◽  
Suzanne Mannes ◽  
James E. Hoffinan

Previous research on the N400 component of the event-related brain potential (ERP) has dealt primarily with measuring the degree of expectancy on the part of the reader as a result of the context within a sentence. Research has shown that when the final word in a sentence is unexpected or incoherent, a greater N400 amplitude is elicited than if the final word is expected or coherent within the context of the sentence. The present study investigated whether the N400 component is sensitive to global, as well as local, semantic expectancy. Global coherence refers to the ease with which subjects can relate the current proposition they are reading with theme-related ideas. In the present study, the effect of global coherence on event-related brain potentials was tested using four titled and untitled paragraphs (Bransford & Johnson, 1972; Dooling & Lachman, 1971), presented one word at a time. These paragraphs are noncoherent, and are made coherent only with the presentation of a title. The EEG was recorded in response to every word in all four paragraphs. We found an increase in N400 amplitude in response to the words in the Untitled paragraphs relative to the Titled paragraphs, indicating that global coherence does affect the N400. In addition, subjects in the Titled group showed an enhanced P1-N1 component relative to the Untitled group suggesting that the presence of global coherence allows greater attention to be allocated to early visual processing of words.

1992 ◽  
Vol 4 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Arti Nigam ◽  
James E. Hoffman ◽  
Robert F. Simons

The N400 component of the human event-related brain potential appears to be related to violations of semantic expectancy during language comprehension. The present experiment investigated whether the N400 is related specifically to activity in a language system or is an index of a conceptual system that is accessed by both pictures and words. Sentences were visually presented one word at a time with the last word being replaced in one condition by a line drawing representing the same concept (eg, the word “socks” was replaced by a picture of socks). The N400 recorded in the Pictures Condition was found to be identical to the N400 generated by words in terms of amplitude, scalp distribution, and latency. These results suggest that the N400 is an index of activity in a conceptual memory that is accessed by both pictures and words.


The construction of directionally selective units, and their use in the processing of visual motion, are considered. The zero crossings of ∇ 2 G(x, y) ∗ I(x, y) are located, as in Marr & Hildreth (1980). That is, the image is filtered through centre-surround receptive fields, and the zero values in the output are found. In addition, the time derivative ∂[∇ 2 G(x, y) ∗ l(x, y) ]/∂ t is measured at the zero crossings, and serves to constrain the local direction of motion to within 180°. The direction of motion can be determined in a second stage, for example by combining the local constraints. The second part of the paper suggests a specific model of the information processing by the X and Y cells of the retina and lateral geniculate nucleus, and certain classes of cortical simple cells. A number of psychophysical and neurophysiological predictions are derived from the theory.


Neuron ◽  
2014 ◽  
Vol 82 (4) ◽  
pp. 887-895 ◽  
Author(s):  
John C. Tuthill ◽  
Aljoscha Nern ◽  
Gerald M. Rubin ◽  
Michael B. Reiser

2018 ◽  
Vol 1 ◽  
pp. 205920431877823 ◽  
Author(s):  
Linda Becker

Musical expertise can lead to neural plasticity in specific cognitive domains (e.g., in auditory music perception). However, not much is known about whether the visual perception of simple musical symbols (e.g., notes) already differs between musicians and non-musicians. This was the aim of the present study. Therefore, the Familiarity Effect (FE) – an effect which occurs quite early during visual processing and which is based on prior knowledge or expertise – was investigated. The FE describes the phenomenon that it is easier to find an unfamiliar element (e.g., a mirrored eighth note) in familiar elements (e.g., normally oriented eighth notes) than to find a familiar element in a background of unfamiliar elements. It was examined whether the strength of the FE for eighth notes differs between note readers and non-note readers. Furthermore, it was investigated at which component of the event-related brain potential (ERP) the FE occurs. Stimuli that consisted of either eighth notes or vertically mirrored eighth notes were presented to the participants (28 note readers, 19 non-note readers). A target element was embedded in half of the trials. Reaction times, sensitivity, and three ERP components (the N1, N2p, and P3) were recorded. For both the note readers and the non-note readers, strong FEs were found in the behavioral data. However, no differences in the strength of the FE between groups were found. Furthermore, for both groups, the FE was found for the same ERP components (target-absent trials – N1 latency; target-present trials – N2p latency, N2p amplitude, P3 amplitude). It is concluded that the early visual perception of eighth note symbols does not differ between note readers and non-note readers. However, future research is needed to verify this for more complex musical stimuli and for professional musicians.


1997 ◽  
Vol 8 (2) ◽  
pp. 95-100 ◽  
Author(s):  
Kimron Shapiro ◽  
Jon Driver ◽  
Robert Ward ◽  
Robyn E. Sorensen

When people must detect several targets in a very rapid stream of successive visual events at the same location, detection of an initial target induces misses for subsequent targets within a brief period. This attentional blink may serve to prevent interruption of ongoing target processing by temporarily suppressing vision for subsequent stimuli. We examined the level at which the internal blink operates, specifically, whether it prevents early visual processing or prevents quite substantial processing from reaching awareness. Our data support the latter view. We observed priming from missed letter targets, benefiting detection of a subsequent target with the same identity but a different case. In a second study, we observed semantic priming from word targets that were missed during the blink. These results demonstrate that attentional gating within the blink operates only after substantial stimulus processing has already taken place. The results are discussed in terms of two forms of visual representation, namely, types and tokens.


The existence of multiple channels, or multiple receptive field sizes, in the visual system does not commit us to any particular theory of spatial encoding in vision. However, distortions of apparent spatial frequency and width in a wide variety of conditions favour the idea that each channel carries a width- or frequency-related code or ‘label’ rather than a ‘local sign’ or positional label. When distortions of spatial frequency occur without prior adaptation (e.g. at low contrast or low luminance) they are associated with lowered sensitivity, and may be due to a mismatch between the perceptual labels and the actual tuning of the channels. A low-level representation of retinal space could be constructed from the spatial information encoded by the channels, rather than being projected intact from the retina.


2011 ◽  
Vol 33 (1) ◽  
pp. 63-74 ◽  
Author(s):  
Karsten Rauss ◽  
Gilles Pourtois ◽  
Patrik Vuilleumier ◽  
Sophie Schwartz

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